/*
 * subject-base.css — Shared styles for all subject pages
 *
 * Each subject still defines its own :root (--primary, --primary-light),
 * loading-screen gradient, topic-tag variants, and dark-mode --primary-light.
 * Everything else lives here.
 *
 * Usage: <link rel="stylesheet" href="../shared/css/subject-base.css">
 *        (loaded AFTER the subject's own :root / variable block)
 */

/* ---- Skip-to-content (accessibility) ---- */
.skip-to-content {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--primary, #4361ee);
    color: #fff;
    padding: 8px 16px;
    z-index: 100000;
    font-size: 14px;
    text-decoration: none;
    border-radius: 0 0 4px 0;
    transition: top 0.2s;
}
.skip-to-content:focus {
    top: 0;
}

/* ---- Reset ---- */
* { margin: 0; padding: 0; box-sizing: border-box; }

/* ---- Shared root variables (non-colour) ---- */
:root {
    --success: #06d6a0;
    --success-light: #e6faf4;
    --error: #ef476f;
    --error-light: #fde8ed;
    --bg: #f0f2f5;
    --card: #ffffff;
    --text: #2b2d42;
    --text-light: #6c757d;
    --radius: 16px;
    --shadow: 0 4px 24px rgba(0,0,0,0.08);
    --warning: #f39c12;
    --warning-light: #fef5e7;
    --border: #e0e0e0;
    --border-light: #f0f0f0;
    --bg-subtle: #f8f9fa;
    /* Design tokens (shared with hub) */
    --color-brand: #534AB7;
    --color-brand-light: #EEEDFE;
    --color-science: #1D9E75;
    --color-humanities: #D85A30;
    --color-arts: #BA7517;
    --color-correct: #1D9E75;
    --color-incorrect: #E24B4A;
    --color-lesson: #00838f;
    --color-lesson-light: #e0f7fa;
    /* Spacing tokens */
    --space-xs: 4px;
    --space-sm: 8px;
    --space-md: 16px;
    --space-lg: 24px;
    --space-xl: 32px;
    /* Typography tokens */
    --font-xs: 11px;
    --font-sm: 13px;
    --font-base: 14px;
    --font-lg: 16px;
    --font-xl: 20px;
    --font-weight-normal: 400;
    --font-weight-medium: 500;
    --font-weight-bold: 700;
    /* Radius tokens */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-pill: 20px;
    --radius-full: 50%;
}

/* ---- Body / App ---- */
body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--bg);
    color: var(--text);
    min-height: 100vh; padding: 20px;
}
#app { max-width: 680px; margin: 0 auto; }
.view { display: none; }
.view.active { display: block; }

/* ---- Hub ---- */
.hub-header { text-align: center; margin-bottom: 32px; }
.hub-header h1 { font-size: 2rem; font-weight: 700; color: var(--primary); margin-bottom: 6px; }
.hub-header p { color: var(--text-light); font-size: 0.95rem; }
header { text-align: center; margin-bottom: 24px; background: var(--card); border-radius: 20px; padding: 20px; box-shadow: var(--shadow); }
header h1 { font-size: 1.8rem; font-weight: 700; color: var(--primary); margin-bottom: 4px; }
header p { color: var(--text-light); font-size: 0.95rem; }

/* ---- Back to hub link ---- */
.back-to-hub { display: inline-flex; align-items: center; gap: 6px; margin-bottom: 8px; font-size: 0.85rem; color: var(--primary); text-decoration: none; font-weight: 600; padding: 8px 14px; border-radius: 10px; background: rgba(255,255,255,0.85); box-shadow: 0 2px 8px rgba(0,0,0,0.06); transition: all 0.2s; }
.back-to-hub:hover { background: #fff; box-shadow: 0 4px 12px rgba(0,0,0,0.1); }

/* ---- Auth bar ---- */
.auth-bar { display: flex; align-items: center; justify-content: center; gap: 10px; margin-top: 12px; }
.auth-avatar { width: 28px; height: 28px; border-radius: 50%; vertical-align: middle; }
.auth-name { font-size: 0.85rem; color: var(--text); font-weight: 600; vertical-align: middle; margin-left: 4px; }
.btn-sm { padding: 6px 14px; font-size: 0.8rem; border-radius: 8px; }

/* ---- Daily streak ---- */
.daily-streak-bar { display: flex; justify-content: center; gap: 24px; margin-top: 14px; }
.daily-streak-item { display: flex; align-items: baseline; gap: 5px; }
.daily-streak-val { font-size: 1.5rem; font-weight: 800; color: #ffc107; }
.daily-streak-label { font-size: 0.78rem; color: var(--text-light); }
.last-updated { font-size: 0.8rem; color: var(--text-light); margin-top: 12px; opacity: 0.7; }

/* ---- Topic grid ---- */
.topic-grid {
    display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px;
}
.topic-card {
    background: var(--card); border-radius: var(--radius);
    box-shadow: var(--shadow); padding: 28px 24px;
    cursor: pointer; transition: all 0.2s ease;
    border: 2px solid transparent;
}
.topic-card:hover { border-color: var(--primary); transform: translateY(-2px); }
.topic-card h2 { font-size: 1.1rem; font-weight: 700; margin-bottom: 6px; color: var(--text); }
.topic-card p { font-size: 0.85rem; color: var(--text-light); line-height: 1.4; }
.section-label { grid-column: 1 / -1; font-size: 0.85rem; color: var(--text-light); margin: 8px 0 -4px 4px; text-transform: uppercase; letter-spacing: 1px; }

/* ---- Topic tags (shared variants) ---- */
.topic-tag {
    display: inline-block; padding: 4px 12px; border-radius: 20px;
    font-size: 0.72rem; font-weight: 700; margin-top: 10px; margin-bottom: 4px; letter-spacing: 0.3px;
}
.topic-tag.lesson { background: #e0f7fa; color: #00838f; }
.topic-tag.lesson-done { background: var(--success-light); color: var(--success); margin-left: 6px; }
.topic-tag.dash { background: var(--primary-light); color: var(--primary); }

/* ---- Back button ---- */
.back-btn {
    display: inline-flex; align-items: center; gap: 6px;
    background: rgba(255,255,255,0.85); border: none; color: var(--primary);
    font-size: 0.9rem; font-weight: 600; cursor: pointer;
    padding: 8px 16px; margin-bottom: 12px; font-family: inherit;
    transition: all 0.2s; border-radius: 10px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.06);
}
.back-btn:hover { background: #fff; box-shadow: 0 4px 12px rgba(0,0,0,0.1); }
.back-btn::before { content: '\2190'; font-size: 1.1rem; }

/* ---- Buttons ---- */
.btn {
    display: inline-block; padding: 12px 28px; border: none;
    border-radius: var(--radius); font-weight: 600;
    font-size: 0.95rem; cursor: pointer; transition: all 0.2s;
}
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { filter: brightness(1.08); transform: translateY(-1px); }
.btn-primary:disabled { opacity: 0.5; cursor: not-allowed; }
.btn-hint { background: var(--primary-light); color: var(--primary); }
.btn-hint:hover { background: var(--primary); color: #fff; }
.btn-hint:disabled { opacity: 0.4; cursor: not-allowed; }

/* ---- Score bar ---- */
.score-bar {
    display: flex; justify-content: center; gap: 32px;
    padding: 16px; background: var(--card);
    border-radius: var(--radius); box-shadow: var(--shadow);
    margin-bottom: 20px;
}
.score-item { text-align: center; }
.score-item .label { font-size: 0.75rem; color: var(--text-light); text-transform: uppercase; letter-spacing: 0.5px; }
.score-item .value { font-size: 1.4rem; font-weight: 700; }
.score-item .value.primary { color: var(--primary); }
.score-item .value.success { color: var(--success); }

/* ---- Level select ---- */
.level-select {
    display: flex; justify-content: center; gap: 8px; margin-bottom: 20px;
}
.level-btn {
    padding: 8px 18px; border: 2px solid var(--primary-light);
    border-radius: 24px; background: var(--card); color: var(--text);
    font-size: 0.82rem; font-weight: 600; cursor: pointer; transition: all 0.15s;
}
.level-btn.active { background: var(--primary); color: #fff; border-color: var(--primary); }

/* ---- Question card ---- */
.question-card {
    background: var(--card); border-radius: var(--radius);
    box-shadow: var(--shadow); padding: 32px 28px;
    margin-bottom: 20px;
}
.difficulty-tag {
    display: inline-block; padding: 3px 12px; border-radius: 16px;
    font-size: 0.72rem; font-weight: 700; margin-bottom: 10px;
    text-transform: uppercase; letter-spacing: 0.5px;
}
.difficulty-tag.easy { background: #d4edda; color: #155724; }
.difficulty-tag.medium { background: #fff3cd; color: #856404; }
.difficulty-tag.hard { background: #f8d7da; color: #721c24; }
.rule-tag { display: inline-block; padding: 3px 12px; border-radius: 16px; font-size: 0.72rem; font-weight: 600; margin-bottom: 14px; margin-left: 6px; background: var(--primary-light); color: var(--primary); }
.question-text { font-size: 1rem; line-height: 1.5; margin-bottom: 14px; }
.question-prompt { font-size: 1.3rem; text-align: center; margin: 18px 0; font-weight: 500; }

/* ---- Options grid (MC) ---- */
.options-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; margin-top: 16px; }
.option-btn {
    padding: 14px 16px; border: 2px solid var(--border);
    border-radius: 12px; background: var(--card); cursor: pointer;
    font-size: 0.92rem; text-align: center; transition: all 0.15s;
}
.option-btn:hover:not(:disabled) { border-color: var(--primary); background: var(--primary-light); }
.option-btn.selected { border-color: var(--primary); background: var(--primary-light); }
.option-btn.correct { border-color: var(--success); background: var(--success-light); }
.option-btn.incorrect { border-color: var(--error); background: var(--error-light); }
.option-btn:disabled { cursor: default; opacity: 0.85; }

/* ---- Input area ---- */
.input-area { display: flex; gap: 10px; justify-content: center; align-items: center; margin-top: 16px; }
.lr-math-field {
    font-size: 1.3rem; padding: 10px 16px;
    border: 2px solid var(--border); border-radius: 12px;
    min-width: 160px; max-width: 260px;
}

/* ---- Hint ---- */
.hint-box {
    background: #fef9e7; border-left: 4px solid #f39c12;
    padding: 14px 18px; border-radius: 0 12px 12px 0;
    margin-bottom: 16px; display: none; font-size: 0.92rem; line-height: 1.5;
}
.hint-box.show { display: block; }

/* ---- Feedback ---- */
.feedback {
    padding: 18px; border-radius: var(--radius); margin-bottom: 16px;
    display: none; text-align: center;
}
.feedback.show { display: block; }
.feedback.correct { background: var(--success-light); border: 2px solid var(--success); }
.feedback.incorrect { background: var(--error-light); border: 2px solid var(--error); }
.feedback-title { font-weight: 700; font-size: 1.1rem; margin-bottom: 6px; }
.feedback.correct .feedback-title { color: var(--success); }
.feedback.incorrect .feedback-title { color: var(--error); }
.feedback-explanation { font-size: 0.92rem; line-height: 1.5; color: var(--text); }
.feedback.partial { background: #fff8e1; border: 2px solid #ffc107; }
.feedback.partial .feedback-title { color: #f57f17; }

/* ---- AI Explain ---- */
.ai-explain-btn {
    display: inline-flex; align-items: center; gap: 6px;
    margin-top: 12px; padding: 8px 16px;
    background: linear-gradient(135deg, #6c63ff, #48b6ff);
    color: #fff; border: none; border-radius: 8px;
    font-size: 0.85rem; font-weight: 600; cursor: pointer;
    transition: opacity 0.2s, transform 0.15s;
}
.ai-explain-btn:hover { opacity: 0.9; transform: translateY(-1px); }
.ai-explain-btn.loading { opacity: 0.7; cursor: wait; }
.ai-explain-btn svg { flex-shrink: 0; }
.ai-spinner {
    display: inline-block; width: 14px; height: 14px;
    border: 2px solid rgba(255,255,255,0.3); border-top-color: #fff;
    border-radius: 50%; animation: aiSpin 0.6s linear infinite;
}
@keyframes aiSpin { to { transform: rotate(360deg); } }
.ai-explain-response {
    margin-top: 10px; padding: 12px 16px;
    background: rgba(108,99,255,0.06); border-left: 3px solid #6c63ff;
    border-radius: 0 8px 8px 0; font-size: 0.9rem; line-height: 1.6;
    color: var(--text);
}
.ai-explain-response code { background: rgba(0,0,0,0.06); padding: 1px 5px; border-radius: 3px; font-size: 0.85em; }
.ai-explain-error { color: var(--error); }
.ai-explain-limit { color: var(--warning); font-weight: 600; }

/* ---- Next button ---- */
.next-btn { display: none; margin: 0 auto; }
.next-btn.show { display: block; }
body.timed-active .next-btn.show { display: none; }

/* ---- Working out ---- */
.workout-section {
    background: var(--card); border-radius: var(--radius);
    box-shadow: var(--shadow); margin-bottom: 20px;
}
details.workout-section { padding: 0; }
details.workout-section summary {
    padding: 16px 24px; cursor: pointer; font-weight: 600;
    color: var(--primary); user-select: none; list-style: none;
}
details.workout-section summary::-webkit-details-marker { display: none; }
details.workout-section summary::before { content: '+ '; font-weight: 700; }
details.workout-section[open] summary::before { content: '\2212 '; }
details.workout-section[open] summary { border-bottom: 1px solid #f0f0f0; }
.workout-content {
    width: calc(100% - 32px); min-height: 150px; margin: 0 16px 16px; padding: 16px;
    border: 2px solid var(--border); border-radius: 12px; background: #fafbfc;
    font-family: 'Cascadia Code','Fira Code',monospace; font-size: 1rem;
    line-height: 1.8; overflow-y: auto; max-height: 400px; outline: none;
}
.copy-calc-btn {
    display: block; margin: 12px 16px 8px; padding: 8px 16px;
    background: var(--primary); color: white; border: none; border-radius: 8px;
    cursor: pointer; font-size: 0.85rem; font-weight: 600; width: calc(100% - 32px);
}
.copy-calc-btn:hover { opacity: 0.9; transform: translateY(-1px); }
.copy-calc-btn:active { transform: translateY(0); }
details.workout-section .copy-calc-btn { margin-bottom: 8px; }

/* ---- Calculator (Desmos) ---- */
.calc-btn {
    position: fixed; bottom: 24px; right: 24px; z-index: 1000;
    width: 56px; height: 56px; border-radius: 50%;
    background: var(--primary); color: #fff; border: none;
    cursor: pointer; font-size: 1.5rem; transition: all 0.2s;
    display: flex; align-items: center; justify-content: center;
}
.calc-btn:hover { transform: scale(1.1); }
.calc-btn.active { background: var(--error); }
.calc-modal {
    display: none; position: fixed; bottom: 90px; right: 24px; z-index: 999;
    width: 380px; height: 500px; background: var(--card);
    border-radius: var(--radius); box-shadow: 0 8px 32px rgba(0,0,0,0.2);
    overflow: hidden; animation: slideUp 0.2s ease;
}
.calc-modal.show { display: block; }
@keyframes slideUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}
.calc-modal .calc-container { width: 100%; height: 100%; touch-action: none; }
.calc-clear-btn { padding: 4px 12px; font-size: 0.78rem; border-radius: 6px; border: 1.5px solid var(--error); background: transparent; color: var(--error); cursor: pointer; font-weight: 600; margin-left: 8px; transition: all 0.2s; }
.calc-clear-btn:hover { background: var(--error); color: white; }
@media (max-width: 480px) {
    .calc-modal { width: calc(100vw - 32px); right: 16px; bottom: 80px; height: 440px; }
    .calc-btn { bottom: 16px; right: 16px; width: 50px; height: 50px; font-size: 1.3rem; }
}

/* ---- Rules reference ---- */
.rules-ref {
    background: var(--card); border-radius: var(--radius);
    box-shadow: var(--shadow); margin-top: 8px;
}
.rules-ref summary {
    padding: 16px 24px; cursor: pointer; font-weight: 600;
    color: var(--primary); user-select: none; list-style: none;
}
.rules-ref summary::-webkit-details-marker { display: none; }
.rules-ref summary::before { content: '+ '; font-weight: 700; }
.rules-ref[open] summary::before { content: '- '; }
.rules-content { padding: 0 24px 20px; }
.rule-item { padding: 10px 0; border-bottom: 1px solid #f0f0f0; font-size: 0.95rem; line-height: 2; }
.rule-item:last-child { border-bottom: none; }
.rule-item .rule-name { font-weight: 700; color: var(--primary); margin-right: 8px; }

/* ---- Lesson Card Differentiation ---- */
.topic-card.lesson-card {
    border-left: 3px solid #00838f;
    background: linear-gradient(135deg, var(--card) 92%, rgba(0,131,143,0.04) 100%);
}
.topic-card.lesson-card::before {
    content: '';
    position: absolute; top: 12px; right: 12px;
    width: 20px; height: 20px;
    background: #e0f7fa;
    border-radius: 50%;
    display: flex; align-items: center; justify-content: center;
}
.topic-card.lesson-card::after {
    content: '\\25B6';
    position: absolute; top: 14px; right: 15px;
    font-size: 10px; color: #00838f; line-height: 1;
}
.topic-card.lesson-card:hover { border-color: #00838f; }
body.dark-mode .topic-card.lesson-card {
    border-left-color: #26c6da;
    background: linear-gradient(135deg, var(--card) 92%, rgba(38,198,218,0.06) 100%);
}
body.dark-mode .topic-card.lesson-card::before { background: rgba(38,198,218,0.15); }
body.dark-mode .topic-card.lesson-card::after { color: #26c6da; }
body.dark-mode .topic-card.lesson-card:hover { border-color: #26c6da; }

/* ---- Lesson view ---- */
.lesson-progress { height: 6px; background: var(--border); border-radius: 3px; margin-bottom: 20px; overflow: hidden; }
.lesson-progress-fill { height: 100%; background: var(--primary); border-radius: 3px; transition: width 0.3s; }
.lesson-content {
    background: var(--card); border-radius: var(--radius);
    box-shadow: var(--shadow); padding: 32px 28px; margin-bottom: 20px;
}
.lesson-content h3 { font-size: 1.15rem; margin-bottom: 14px; color: var(--primary); }
.lesson-box {
    background: var(--primary-light); border-left: 4px solid var(--primary);
    padding: 16px 20px; border-radius: 0 12px 12px 0;
    margin: 14px 0; font-size: 0.95rem; line-height: 1.6;
}
.lesson-step { opacity: 0; max-height: 0; overflow: hidden; transition: all 0.4s ease; padding: 0 12px; margin: 0; font-size: 0.95rem; }
.lesson-step.revealed { opacity: 1; max-height: 200px; padding: 10px 12px; margin: 8px 0; background: var(--bg-subtle); border-radius: 8px; }
.lesson-btn-row { display: flex; gap: 12px; justify-content: center; margin-top: 8px; }
.lesson-score { font-size: 1.1rem; margin: 12px 0 18px; text-align: center; }

/* ---- Dashboard ---- */
.dash-overview { display: flex; gap: 12px; margin-bottom: 20px; flex-wrap: wrap; justify-content: center; }
.dash-stat { background: var(--card); border-radius: 12px; padding: 16px 20px; text-align: center; min-width: 110px; box-shadow: var(--shadow); }
.dash-stat-value { font-size: 1.5rem; font-weight: 800; }
.dash-stat-label { font-size: 0.75rem; color: var(--text-light); text-transform: uppercase; margin-top: 4px; }
.dash-topic { background: var(--card); border-radius: 12px; padding: 16px; margin-bottom: 12px; box-shadow: var(--shadow); }
.dash-topic-header { font-weight: 700; font-size: 0.95rem; margin-bottom: 10px; color: var(--primary); }
.dash-lesson-count { font-size: 0.78rem; color: var(--text-light); font-weight: 400; float: right; }
.dash-row { display: flex; align-items: center; gap: 10px; padding: 6px 0; }
.dash-row-label { min-width: 120px; font-size: 0.85rem; font-weight: 500; }
.dash-row-bar { flex: 1; height: 8px; background: #e9ecef; border-radius: 4px; overflow: hidden; }
.dash-row-fill { height: 100%; border-radius: 4px; transition: width 0.5s; }
.dash-row-stat { font-size: 0.82rem; min-width: 55px; text-align: right; }
.dash-row-pct { font-size: 0.82rem; font-weight: 700; min-width: 40px; text-align: right; }
.hist-row { display: flex; align-items: center; gap: 10px; padding: 4px 0; font-size: 0.82rem; }
.hist-name { flex: 1; font-weight: 500; }
.hist-date { color: var(--text-light); min-width: 50px; }
.hist-score { min-width: 45px; text-align: right; }
.hist-pct { font-weight: 700; min-width: 35px; text-align: right; }

/* ---- Leaderboard ---- */
.lb-table { width: 100%; border-collapse: collapse; font-size: 0.85rem; background: var(--card); border-radius: var(--radius); box-shadow: var(--shadow); overflow: hidden; }
.lb-table th { background: var(--primary-light); color: var(--primary); padding: 10px 8px; text-align: left; }
.lb-table td { padding: 10px 8px; border-bottom: 1px solid var(--border-light); }
.lb-table tr.lb-me { background: #fff8e1; }
.lb-avatar { width: 24px; height: 24px; border-radius: 50%; vertical-align: middle; margin-right: 6px; }
.lb-school { font-size: 0.8rem; color: var(--text-light); max-width: 140px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.lb-pos { font-weight: 800; color: var(--primary); width: 30px; }

/* ---- Settings dropdown ---- */
.settings-dropdown {
    display: none; background: var(--card); border-radius: var(--radius);
    box-shadow: var(--shadow); padding: 16px 20px; margin-top: 12px;
    text-align: left;
}
.settings-dropdown.show { display: block; }
.settings-item { display: flex; align-items: center; justify-content: space-between; padding: 8px 0; gap: 10px; }
.settings-item span { font-size: 0.85rem; }
#font-selector { font-size: 0.82rem; padding: 4px 8px; border-radius: 6px; border: 1px solid #ccc; }

/* ---- Continue prompt ---- */
.continue-card {
    background: var(--card); border-radius: var(--radius);
    box-shadow: var(--shadow); padding: 16px 20px;
    margin-bottom: 20px; display: flex; align-items: center; gap: 16px;
    cursor: pointer; transition: all 0.2s; border: 2px solid transparent;
}
.continue-card:hover { border-color: var(--primary); }
.continue-left { flex: 1; }
.continue-label { font-size: 0.78rem; color: var(--text-light); text-transform: uppercase; letter-spacing: 0.5px; }
.continue-name { font-size: 1rem; font-weight: 700; margin-top: 2px; }
.continue-stats { font-size: 0.82rem; color: var(--text-light); margin-top: 2px; }
.continue-arrow { font-size: 1.5rem; color: var(--primary); }

/* ---- Timed challenge ---- */
.timed-btn {
    padding: 10px 24px; border: 2px solid var(--primary);
    border-radius: 24px; background: var(--card); color: var(--primary);
    font-size: 0.85rem; font-weight: 700; cursor: pointer; transition: all 0.15s;
}
.timed-btn:hover { background: var(--primary); color: #fff; }
.timed-timer {
    position: fixed; top: 0; left: 0; right: 0; height: 6px; z-index: 999;
    background: #e9ecef;
}
.timed-timer-fill { height: 100%; background: var(--primary); transition: width 1s linear; }
.timed-timer-text {
    position: fixed; top: 8px; right: 16px; z-index: 1000;
    font-size: 0.9rem; font-weight: 800; color: var(--primary);
}
.timed-overlay {
    position: fixed; inset: 0; background: rgba(0,0,0,0.5);
    display: none; align-items: center; justify-content: center; z-index: 10000;
}
.timed-results {
    background: var(--card); border-radius: var(--radius); padding: 40px;
    max-width: 400px; width: 90%; text-align: center; box-shadow: 0 8px 40px rgba(0,0,0,0.2);
}
.timed-results h2 { color: var(--primary); margin-bottom: 20px; }
.timed-stat-grid { display: flex; gap: 16px; justify-content: center; margin-bottom: 24px; }
.timed-stat { text-align: center; }
.timed-stat-val { font-size: 1.4rem; font-weight: 800; color: var(--primary); }
.timed-stat-lbl { font-size: 0.75rem; color: var(--text-light); }
.timed-btn-row { display: flex; gap: 12px; justify-content: center; }

/* ---- Feedback floating ---- */
.fb-float-btn {
    position: fixed; bottom: 24px; right: 90px; width: 48px; height: 48px;
    border-radius: 50%; border: none; background: var(--primary);
    color: #fff; font-size: 1.3rem; cursor: pointer; box-shadow: 0 4px 16px rgba(0,0,0,0.2);
    z-index: 900; transition: transform 0.2s;
}
.fb-float-btn:hover { transform: scale(1.1); }
.fb-float-panel {
    position: fixed; bottom: 80px; right: 90px; width: 320px;
    background: var(--card); border-radius: var(--radius); box-shadow: 0 8px 32px rgba(0,0,0,0.15);
    z-index: 901; display: none; overflow: hidden;
}
.fb-float-panel.show { display: block; }
.fb-float-header { display: flex; justify-content: space-between; align-items: center; padding: 14px 18px; background: var(--primary); color: #fff; font-weight: 700; }
.fb-float-close { background: none; border: none; color: #fff; font-size: 1.3rem; cursor: pointer; }
.fb-float-body { padding: 16px 18px; }
.fb-float-body select { width: 100%; padding: 8px; border-radius: 8px; border: 1px solid #ccc; margin-bottom: 10px; font-size: 0.85rem; }
.fb-float-body textarea { width: 100%; height: 100px; padding: 10px; border-radius: 8px; border: 1px solid #ccc; resize: vertical; font-size: 0.85rem; margin-bottom: 10px; }
.fb-confirmation { display: none; text-align: center; color: var(--success); font-weight: 600; margin-top: 8px; }
.fb-confirmation.show { display: block; }

/* ---- Dark Mode (shared overrides — subject sets --primary-light) ---- */
body.dark-mode {
    --bg: #1a1a2e;
    --card: #16213e;
    --text: #e0e0e0;
    --text-light: #a0a0b0;
    --shadow: 0 4px 24px rgba(0,0,0,0.3);
}
body.dark-mode .back-to-hub { background: rgba(22,33,62,0.85); color: var(--primary); }
body.dark-mode .back-to-hub:hover { background: var(--card); }
body.dark-mode .back-btn { background: rgba(22,33,62,0.85); color: var(--primary); }
body.dark-mode .back-btn:hover { background: var(--card); }
body.dark-mode .question-card { background: var(--card); }
body.dark-mode .option-btn { background: var(--card); border-color: #333; color: var(--text); }
body.dark-mode .option-btn:hover:not(:disabled) { border-color: var(--primary); }
body.dark-mode .workout-content { border-color: #444; background: #1a1a2e; color: var(--text); }
body.dark-mode details.workout-section[open] summary { border-bottom-color: #333; }
body.dark-mode .lesson-step.revealed { background: #1a1a2e; }
body.dark-mode .hint-box { background: #2a2a3e; border-left-color: var(--warning); }
body.dark-mode .lb-table th { background: var(--primary-light); }
body.dark-mode .lb-table td { border-bottom-color: #333; }
body.has-bg .lb-table { background: rgba(255,255,255,0.92); backdrop-filter: blur(18px); -webkit-backdrop-filter: blur(18px); }
body.dark-mode.has-bg .lb-table { background: rgba(22,33,62,0.92); }
body.dark-mode .rules-ref[open] summary { border-bottom-color: #333; }
body.dark-mode .timed-results { background: var(--card); }

/* ---- Background overlay ---- */
.bg-overlay {
    position: fixed; inset: 0; z-index: -1;
    background-size: cover; background-position: center;
    opacity: 0; pointer-events: none;
}
body.has-bg { background: transparent; }
body.has-bg .bg-overlay { z-index: 0; }
body.has-bg #app { position: relative; z-index: 1; }
body.has-bg .topic-card,
body.has-bg .question-card,
body.has-bg .score-bar,
body.has-bg .lesson-content,
body.has-bg .dash-stat,
body.has-bg .dash-topic,
body.has-bg .continue-card,
body.has-bg header { background: rgba(255,255,255,0.85); backdrop-filter: blur(8px); }
body.has-bg .hub-header { background: rgba(255,255,255,0.85); backdrop-filter: blur(16px); -webkit-backdrop-filter: blur(16px); border-radius: var(--radius); padding: 20px; margin-bottom: 24px; }
body.has-bg .hub-header h1 { color: var(--primary); }
body.has-bg .hub-header p { color: var(--text-light); }
body.has-bg.dark-mode .hub-header { background: rgba(22,33,62,0.85); }
body.has-bg.dark-mode .topic-card,
body.has-bg.dark-mode .question-card,
body.has-bg.dark-mode .score-bar,
body.has-bg.dark-mode .lesson-content,
body.has-bg.dark-mode .dash-stat,
body.has-bg.dark-mode .dash-topic,
body.has-bg.dark-mode .continue-card,
body.has-bg.dark-mode header { background: rgba(22,33,62,0.85); }

/* ---- Loading screen (shared structure — subject overrides .loading-screen background & .loading-bar gradient) ---- */
.loading-screen {
    position: fixed; inset: 0; z-index: 99999;
    display: flex; align-items: center; justify-content: center;
    transition: opacity 0.8s cubic-bezier(.4,0,.2,1), visibility 0.8s;
    overflow: hidden;
}
.loading-screen.hidden { opacity: 0; visibility: hidden; pointer-events: none; }
.loading-screen.hidden .loading-content { transform: scale(0.9) translateY(-20px); }
.loading-content {
    text-align: center; position: relative; z-index: 2;
    transition: transform 0.8s cubic-bezier(.4,0,.2,1);
}
.loading-icon { margin: 0 auto 20px; }
.loading-title { color: #fff; font-size: 1.8rem; font-weight: 800; letter-spacing: -0.5px; margin-bottom: 12px; }
.loading-fact {
    color: rgba(255,255,255,0.55); font-size: 0.85rem; margin-top: 0;
    min-height: 1.4em; transition: opacity 0.4s;
}
.loading-fact.fade { opacity: 0; }
.loading-bar-wrap {
    width: 200px; height: 4px; background: rgba(255,255,255,0.1);
    border-radius: 4px; margin: 18px auto 0; overflow: hidden;
}
.loading-bar {
    height: 100%; width: 0%; border-radius: 4px;
    background-size: 200% 100%;
    animation: bar-shimmer 1.5s ease-in-out infinite;
    transition: width 0.3s ease;
}
@keyframes bar-shimmer { 0%{background-position:0% 0%} 50%{background-position:100% 0%} 100%{background-position:0% 0%} }
.loading-counter {
    color: rgba(255,255,255,0.35); font-size: 0.75rem; margin-top: 8px;
    font-variant-numeric: tabular-nums;
}
/* Floating symbols */
.loading-floats { position: absolute; inset: 0; overflow: hidden; z-index: 1; }
.loading-float-sym {
    position: absolute; color: rgba(255,255,255,0.06); font-size: 1.4rem;
    animation: float-up linear infinite; pointer-events: none; user-select: none;
}
@keyframes float-up {
    0% { transform: translateY(100vh) rotate(0deg); opacity: 0; }
    10% { opacity: 1; }
    90% { opacity: 1; }
    100% { transform: translateY(-10vh) rotate(360deg); opacity: 0; }
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ---- Music button ---- */
.music-btn {
    position: fixed; bottom: 24px; left: 24px; width: 42px; height: 42px;
    border-radius: 50%; border: none; background: var(--card);
    font-size: 1.2rem; cursor: pointer; box-shadow: var(--shadow);
    z-index: 900; opacity: 0.7; transition: opacity 0.2s;
}
.music-btn:hover { opacity: 1; }
.music-btn.playing { opacity: 1; color: var(--primary); }

/* ---- Extended answer ---- */
.extended-area { margin-top: 16px; }
.extended-textarea {
    width: 100%; min-height: 120px; padding: 14px; border: 2px solid var(--border);
    border-radius: 12px; font-size: 0.95rem; font-family: inherit;
    line-height: 1.6; resize: vertical; background: var(--card); color: var(--text);
    transition: border-color 0.2s;
}
.extended-textarea:focus { border-color: var(--primary); outline: none; }
.extended-meta { display: flex; justify-content: space-between; align-items: center; margin-top: 8px; }
.word-count { font-size: 0.78rem; color: var(--text-light); }
.mark-breakdown { text-align: left; margin: 12px 0; }
.mark-row { display: flex; align-items: flex-start; gap: 8px; padding: 6px 0; font-size: 0.9rem; }
.mark-icon { font-size: 1rem; min-width: 20px; text-align: center; }
.mark-icon.awarded { color: var(--success); }
.mark-icon.missed { color: var(--error); }
.mark-text { flex: 1; }
.model-answer {
    background: var(--bg-subtle); border-left: 4px solid var(--primary);
    padding: 12px 16px; border-radius: 0 8px 8px 0;
    margin-top: 12px; font-size: 0.88rem; line-height: 1.5;
}
body.dark-mode .extended-textarea { background: #1a1a2e; border-color: #444; color: var(--text); }
body.dark-mode .model-answer { background: #1a1a2e; }
body.dark-mode .feedback.partial { background: rgba(255,248,225,0.1); border-color: #ffc107; }

/* ---- Paper Generator (shared structure) ---- */
.pg-mode-select { display: flex; justify-content: center; gap: 8px; margin-bottom: 20px; }
.pg-mode-btn {
    padding: 10px 24px; border: 2px solid var(--primary-light);
    border-radius: 24px; background: var(--card); color: var(--text);
    font-size: 0.88rem; font-weight: 600; cursor: pointer; transition: all 0.15s;
}
.pg-mode-btn.active { background: var(--primary); color: #fff; border-color: var(--primary); }
.pg-setup-card {
    background: var(--card); border-radius: var(--radius);
    box-shadow: var(--shadow); padding: 24px; margin-bottom: 16px;
}
.pg-setup-card h3 { font-size: 1rem; font-weight: 700; margin-bottom: 8px; color: var(--primary); }
.pg-desc { font-size: 0.85rem; color: var(--text-light); margin-bottom: 16px; }
.pg-option-row { display: flex; align-items: flex-start; gap: 12px; padding: 8px 0; }
.pg-option-row > label { min-width: 60px; font-size: 0.85rem; font-weight: 600; padding-top: 4px; }
.pg-topic-checks { display: flex; flex-wrap: wrap; gap: 8px; }
.pg-check { font-size: 0.82rem; display: flex; align-items: center; gap: 4px; cursor: pointer; }
.pg-check input { accent-color: var(--primary); }
.pg-select {
    padding: 8px 12px; border-radius: 8px; border: 1px solid #ccc;
    font-size: 0.85rem; background: var(--card); color: var(--text);
}

/* History */
.pg-history { margin-top: 8px; }
.pg-history-row {
    display: flex; align-items: center; gap: 10px; padding: 6px 0;
    border-bottom: 1px solid var(--border-light); font-size: 0.82rem;
}
.pg-hist-date { min-width: 50px; color: var(--text-light); }
.pg-hist-mode { flex: 1; font-weight: 500; }
.pg-hist-score { min-width: 50px; text-align: right; font-weight: 600; }
.pg-hist-grade { min-width: 60px; text-align: right; color: var(--primary); font-weight: 700; }
.pg-hist-del { background: none; border: none; color: var(--text-light); cursor: pointer; font-size: 0.9rem; padding: 2px 6px; border-radius: 4px; opacity: 0.5; transition: opacity 0.2s; }
.pg-hist-del:hover { opacity: 1; color: var(--error); }
.pg-hist-actions { display: flex; justify-content: flex-end; padding: 6px 0 2px; }
.pg-hist-clear { background: none; border: none; color: var(--error); cursor: pointer; font-size: 0.78rem; opacity: 0.7; }
.pg-hist-clear:hover { opacity: 1; text-decoration: underline; }
.pg-history-row.clickable { cursor: pointer; border-radius: 6px; padding: 6px 8px; margin: 0 -8px; transition: background 0.15s; }
.pg-history-row.clickable:hover { background: rgba(99,102,241,0.08); }

/* Active view */
.pg-top-bar {
    display: flex; align-items: center; justify-content: space-between;
    margin-bottom: 16px; gap: 12px;
}
.pg-timer {
    flex: 1; height: 8px; background: #e9ecef; border-radius: 4px;
    overflow: hidden; position: relative;
}
.pg-timer-fill { height: 100%; background: var(--primary); transition: width 1s linear; width: 100%; }
.pg-timer-text { font-size: 0.85rem; font-weight: 800; color: var(--primary); white-space: nowrap; }
.pg-mark-tally { font-size: 0.82rem; color: var(--text-light); font-weight: 600; white-space: nowrap; }

/* Nav strip */
.pg-nav-strip {
    display: flex; flex-wrap: wrap; gap: 4px; align-items: center;
    margin-bottom: 16px; padding: 10px;
    background: var(--card); border-radius: var(--radius); box-shadow: var(--shadow);
    overflow-x: auto;
}
.pg-nav-btn {
    padding: 4px 8px; border: 2px solid var(--border); border-radius: 8px;
    background: var(--card); font-size: 0.72rem; font-weight: 600;
    cursor: pointer; transition: all 0.15s; white-space: nowrap;
}
.pg-nav-btn.active { border-color: var(--primary); background: var(--primary-light); color: var(--primary); }
.pg-nav-btn.answered.correct { background: var(--success-light); border-color: var(--success); }
.pg-nav-btn.answered.incorrect { background: var(--error-light); border-color: var(--error); }
.pg-nav-sep { color: var(--text-light); font-size: 0.85rem; margin: 0 2px; }

/* Context box */
.pg-context-text { color: var(--text); }

/* Part card */
.pg-part-header { display: flex; align-items: center; gap: 10px; margin-bottom: 12px; flex-wrap: wrap; }
.pg-part-label { font-weight: 800; font-size: 1.1rem; color: var(--primary); }
.pg-command-word {
    display: inline-block; padding: 3px 10px; border-radius: 12px;
    background: var(--primary-light); color: var(--primary);
    font-size: 0.75rem; font-weight: 700; text-transform: uppercase;
}
.pg-marks-badge {
    font-size: 0.75rem; font-weight: 600; color: var(--text-light);
}
.pg-part-text { font-size: 0.95rem; line-height: 1.5; margin-bottom: 14px; }
.pg-unit-hint { font-size: 0.78rem; color: var(--text-light); text-align: center; margin-top: 6px; }

/* Bottom nav */
.pg-bottom-nav { display: flex; gap: 12px; justify-content: center; margin-top: 16px; }

/* Results view */
.pg-results-header { text-align: center; margin-bottom: 24px; }
.pg-grade-num { font-size: 2.5rem; font-weight: 900; color: #fff; line-height: 1; }
.pg-grade-label { font-size: 0.7rem; color: rgba(255,255,255,0.8); font-weight: 600; }
.pg-results-summary { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.pg-result-stat { text-align: center; }
.pg-result-val { display: block; font-size: 1.3rem; font-weight: 800; color: var(--primary); }
.pg-result-lbl { font-size: 0.75rem; color: var(--text-light); }
.pg-section-title { font-size: 0.9rem; font-weight: 700; color: var(--primary); margin: 20px 0 10px; text-transform: uppercase; letter-spacing: 0.5px; }

/* Question breakdown */
.pg-q-breakdown {
    background: var(--card); border-radius: 12px; padding: 12px 16px;
    margin-bottom: 8px; box-shadow: var(--shadow);
}
.pg-q-breakdown summary {
    cursor: pointer; font-size: 0.88rem; font-weight: 600;
    display: flex; align-items: center; gap: 8px;
}
.pg-q-score { margin-left: auto; font-size: 0.82rem; font-weight: 700; color: var(--primary); }
.pg-q-details { padding: 8px 0 4px; }
.pg-part-result { display: flex; align-items: center; gap: 8px; padding: 4px 0; font-size: 0.85rem; }
.pg-part-lbl { flex: 1; }
.pg-part-marks { font-weight: 700; min-width: 40px; text-align: right; }
.pg-part-model { font-size: 0.82rem; color: var(--text-light); padding: 4px 0 4px 28px; line-height: 1.5; }

/* Command word analysis */
.pg-cw-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(140px, 1fr)); gap: 10px; }
.pg-cw-card {
    background: var(--card); border-radius: 10px; padding: 12px;
    box-shadow: var(--shadow); text-align: center;
}
.pg-cw-name { font-size: 0.82rem; font-weight: 700; margin-bottom: 6px; }
.pg-cw-bar { height: 8px; background: #e9ecef; border-radius: 4px; overflow: hidden; margin-bottom: 4px; }
.pg-cw-fill { height: 100%; border-radius: 4px; transition: width 0.5s; }
.pg-cw-score { font-size: 0.75rem; color: var(--text-light); }

/* Topic performance */
.pg-topic-grid { display: flex; flex-direction: column; gap: 8px; }
.pg-topic-bar-item { display: flex; align-items: center; gap: 10px; font-size: 0.85rem; }
.pg-topic-name { min-width: 80px; font-weight: 600; }
.pg-topic-pct { min-width: 40px; text-align: right; font-weight: 700; }

/* Reading Time */
.pg-reading-banner {
    background: linear-gradient(135deg, #6c3483, #8e44ad);
    color: white;
    text-align: center;
    padding: 16px 20px;
    border-radius: 12px;
    margin-bottom: 16px;
    box-shadow: 0 4px 15px rgba(108,52,131,0.3);
}
.pg-reading-title { font-size: 1.1em; font-weight: 600; text-transform: uppercase; letter-spacing: 1px; }
.pg-reading-countdown { font-size: 2em; font-weight: 700; font-variant-numeric: tabular-nums; margin: 4px 0; }
.pg-reading-note { font-size: 0.85em; opacity: 0.85; }
.paper-reading-time .pg-option,
.paper-reading-time .pg-submit-btn,
.paper-reading-time .pg-copy-calc,
.paper-reading-time .pg-math-field,
.paper-reading-time .pg-extended-textarea,
.paper-reading-time .pg-working-textarea,
.paper-reading-time .pg-working-content { pointer-events: none !important; opacity: 0.4; }
.paper-reading-time .pg-finish-btn { display: none !important; }

/* Dark mode paper gen */
body.dark-mode .pg-setup-card { background: var(--card); }
body.dark-mode .pg-nav-strip { background: var(--card); }
body.dark-mode .pg-nav-btn { background: var(--card); border-color: #444; }
body.dark-mode .pg-q-breakdown { background: var(--card); }
body.dark-mode .pg-cw-card { background: var(--card); }
body.dark-mode .pg-history-row { border-bottom-color: #333; }
body.dark-mode .pg-select { background: #1a1a2e; border-color: #444; color: var(--text); }

/* Glassmorphism for paper gen */
body.has-bg .pg-setup-card,
body.has-bg .pg-nav-strip,
body.has-bg .pg-context-box,
body.has-bg .pg-q-breakdown,
body.has-bg .pg-cw-card { background: rgba(255,255,255,0.85); backdrop-filter: blur(8px); }
body.has-bg.dark-mode .pg-setup-card,
body.has-bg.dark-mode .pg-nav-strip,
body.has-bg.dark-mode .pg-context-box,
body.has-bg.dark-mode .pg-q-breakdown,
body.has-bg.dark-mode .pg-cw-card { background: rgba(22,33,62,0.85); }

/* ---- Mark Scheme ---- */
.pg-ms-topbar { display: flex; gap: 12px; margin-bottom: 20px; flex-wrap: wrap; }
.pg-ms-topbar .btn { font-size: 0.9rem; }
.pg-ms-question { background: var(--card, #ffffff); border-radius: 12px; padding: 20px; margin-bottom: 20px; border: 1px solid var(--border); }
.pg-ms-question h3 { margin: 0 0 12px; font-size: 1.1rem; }
.pg-ms-context { font-size: 0.95rem; color: var(--text-light); margin-bottom: 16px; padding: 12px; background: var(--bg); border-radius: 8px; }
.pg-ms-part { margin-bottom: 16px; padding-left: 16px; border-left: 3px solid var(--border); }
.pg-ms-part-header { display: flex; align-items: center; gap: 8px; margin-bottom: 8px; flex-wrap: wrap; }
.pg-ms-part-label { font-weight: 700; color: var(--primary); }
.pg-ms-command { font-size: 0.8rem; background: rgba(99,102,241,0.1); color: var(--primary); padding: 2px 8px; border-radius: 4px; }
.pg-ms-marks { font-size: 0.8rem; color: var(--text-light); }
.pg-ms-part-text { margin-bottom: 8px; }
.pg-ms-answer { background: rgba(34,197,94,0.08); border-left: 4px solid var(--success); padding: 12px 16px; border-radius: 0 8px 8px 0; margin-bottom: 8px; }
.pg-ms-answer strong { color: var(--success); }
.pg-ms-options { display: flex; flex-direction: column; gap: 4px; margin-bottom: 8px; }
.pg-ms-opt { padding: 6px 12px; border-radius: 6px; font-size: 0.9rem; }
.pg-ms-opt.correct { background: rgba(34,197,94,0.15); font-weight: 700; }
.pg-ms-markscheme { margin-top: 8px; }
.pg-ms-markscheme-title { font-size: 0.85rem; font-weight: 700; margin-bottom: 4px; color: var(--text-light); }
.pg-ms-mark-row { display: flex; align-items: flex-start; gap: 8px; padding: 4px 0; font-size: 0.9rem; }
.pg-ms-mark-bullet { color: var(--success); font-weight: 700; flex-shrink: 0; }
.pg-ms-model { background: var(--bg); padding: 12px; border-radius: 8px; margin-top: 8px; font-size: 0.9rem; line-height: 1.6; }
.pg-ms-model strong { display: block; margin-bottom: 4px; }

/* Working out area (paper generator) */
.pg-working { margin-bottom: 12px; }
.pg-working summary { font-size: 0.82rem; font-weight: 600; color: var(--primary); cursor: pointer; padding: 4px 0; }
.pg-working-textarea { width: 100%; border: 1.5px dashed var(--border, #e0e0e0); border-radius: 8px; padding: 10px; font-size: 0.88rem; font-family: inherit; resize: vertical; min-height: 60px; background: var(--bg); color: var(--text); margin-top: 6px; }
.pg-working-textarea:focus { border-color: var(--primary); outline: none; }
.pg-working-content { width: 100%; border: 1.5px dashed var(--border, #e0e0e0); border-radius: 8px; padding: 10px; font-size: 0.88rem; font-family: inherit; min-height: 60px; background: var(--bg); color: var(--text); margin-top: 6px; overflow-y: auto; max-height: 300px; }
.pg-working-content:focus { border-color: var(--primary); outline: none; }
.pg-working-content:empty::before { content: 'Show your working here...'; color: var(--text-light); opacity: 0.5; }
body.dark-mode .pg-working-textarea { background: #1a1a2e; border-color: #444; color: var(--text); }
body.dark-mode .pg-working-content { background: #1a1a2e; border-color: #444; color: var(--text); }
.pg-working-marked .pg-working-textarea { border-style: solid; min-height: 80px; }
.pg-working-marked .pg-working-content { border-style: solid; min-height: 80px; }
.pg-working-marked .pg-working-content:empty::before { content: 'Show your working step by step...'; }
.pg-working-header { font-size: 0.85rem; font-weight: 700; color: var(--primary); margin-bottom: 6px; }
.pg-working-marks { font-size: 0.75rem; font-weight: 600; color: var(--text-light); margin-left: 6px; }
.pg-answer-mark { font-size: 0.8rem; color: var(--text-light); }
.pg-working-feedback { margin-top: 10px; padding-top: 10px; border-top: 1px solid var(--border, #e0e0e0); }
.pg-working-fb-title { font-size: 0.82rem; font-weight: 700; color: var(--primary); margin-bottom: 4px; }
.pg-mark-breakdown { text-align: left; margin: 8px 0; }
.pg-mark-row { display: flex; align-items: flex-start; gap: 8px; padding: 4px 0; font-size: 0.88rem; }
.pg-mark-icon { font-size: 1rem; min-width: 20px; text-align: center; }
.pg-mark-icon.awarded { color: var(--success); }
.pg-mark-icon.missed { color: var(--error); }
.pg-mark-text { flex: 1; }

@media print {
    body * { visibility: hidden; }
    #view-paper-markscheme, #view-paper-markscheme * { visibility: visible; }
    #view-paper-markscheme { position: absolute; left: 0; top: 0; width: 100%; }
    .pg-ms-topbar, .back-btn, nav, .wallpaper-bg { display: none !important; }
    .pg-ms-question { break-inside: avoid; border: 1px solid #ccc; }
    .pg-ms-answer { background: #f0fdf4 !important; border-left: 4px solid #22c55e; }
    .pg-ms-opt.correct { background: #f0fdf4 !important; }
    * { color: #000 !important; }
}

/* ---- Formula Booklet ---- */
.formula-section { background: var(--card-bg, rgba(255,255,255,0.92)); border-radius: 12px; padding: 16px 20px; margin-bottom: 16px; box-shadow: 0 2px 8px rgba(0,0,0,0.08); }
.formula-section h3 { color: var(--primary); border-bottom: 2px solid var(--primary); padding-bottom: 4px; margin-bottom: 8px; margin-top: 0; }
.formula-table { width: 100%; border-collapse: collapse; }
.formula-table td, .formula-table th { padding: 8px 12px; border-bottom: 1px solid rgba(128,128,128,0.15); }
.formula-table td:first-child, .formula-table th:first-child { width: 40%; font-weight: 500; }
.formula-table td:last-child, .formula-table th:last-child { text-align: center; }
.formula-table tr:last-child td { border-bottom: none; }
.formula-table tr:hover { background: rgba(128,128,128,0.05); }
/* Formula FAB */
.formula-fab { position: fixed; bottom: 24px; right: 24px; width: 52px; height: 52px; border-radius: 50%; background: var(--primary); color: #fff; border: none; font-size: 1.4rem; cursor: pointer; z-index: 999; box-shadow: 0 4px 14px rgba(0,0,0,0.3); display: none; align-items: center; justify-content: center; transition: transform 0.2s; }
.formula-fab:hover { transform: scale(1.1); }
/* Formula slide-out panel */
.formula-panel-backdrop { position: fixed; top: 0; left: 0; right: 0; bottom: 0; background: rgba(0,0,0,0.4); z-index: 1000; opacity: 0; pointer-events: none; transition: opacity 0.3s; }
.formula-panel-backdrop.open { opacity: 1; pointer-events: auto; }
.formula-panel { position: fixed; top: 0; right: 0; width: 420px; max-width: 90vw; height: 100vh; background: var(--bg, #fff); z-index: 1001; overflow-y: auto; padding: 20px; box-shadow: -4px 0 24px rgba(0,0,0,0.2); transform: translateX(100%); transition: transform 0.3s ease; }
.formula-panel.open { transform: translateX(0); }
.formula-panel .formula-section { box-shadow: none; background: rgba(128,128,128,0.06); }
.formula-panel-close { background: none; border: none; font-size: 1.5rem; cursor: pointer; color: var(--text); padding: 4px 10px; border-radius: 8px; margin-bottom: 12px; }
.formula-panel-close:hover { background: rgba(128,128,128,0.1); }

/* ---- Gem Counter ---- */
.gem-val { color: #a855f7 !important; }

/* ---- Freeze Dots ---- */
.freeze-dots { display: flex; align-items: center; gap: 4px; flex-wrap: wrap; justify-content: center; }
.freeze-dot {
    width: 14px; height: 14px; border-radius: 50%; border: 2px solid #60a5fa;
    background: transparent; display: inline-block; transition: background 0.3s;
}
.freeze-dot.filled { background: #60a5fa; box-shadow: 0 0 6px rgba(96,165,250,0.5); }

/* ---- Gem Toast ---- */
.gem-toast {
    position: fixed; top: 20px; left: 50%; transform: translateX(-50%) translateY(-80px);
    z-index: 9999; background: linear-gradient(135deg, #a855f7, #7c3aed);
    color: #fff; padding: 10px 24px; border-radius: 30px;
    font-weight: 700; font-size: 0.95rem; white-space: nowrap;
    box-shadow: 0 4px 20px rgba(168,85,247,0.4);
    transition: transform 0.5s cubic-bezier(.34,1.56,.64,1), opacity 0.4s;
}
.gem-toast.show { transform: translateX(-50%) translateY(0); }
.gem-toast.out { transform: translateX(-50%) translateY(-80px); opacity: 0; }

/* ---- Streak Reminder Banner ---- */
.streak-reminder {
    position: fixed; top: 0; left: 0; right: 0; z-index: 9990;
    background: linear-gradient(135deg, #f59e0b, #ea580c);
    color: #fff; padding: 12px 48px 12px 20px; text-align: center;
    font-weight: 600; font-size: 0.9rem;
    transform: translateY(-100%); transition: transform 0.4s ease;
}
.streak-reminder.show { transform: translateY(0); }
.streak-reminder-close {
    position: absolute; right: 12px; top: 50%; transform: translateY(-50%);
    background: none; border: none; color: #fff; font-size: 1.4rem; cursor: pointer;
    padding: 4px 8px; opacity: 0.8;
}
.streak-reminder-close:hover { opacity: 1; }

/* ---- Weekly Reward Banner ---- */
.lb-reward-banner { position: fixed; top: 0; left: 0; right: 0; z-index: 9991; background: linear-gradient(135deg, #f59e0b, #d97706, #b45309); color: #fff; padding: 12px 48px 12px 20px; text-align: center; font-weight: 600; font-size: 0.9rem; transform: translateY(-100%); transition: transform 0.4s ease; }
.lb-reward-banner.show { transform: translateY(0); }
.lb-reward-close { position: absolute; right: 12px; top: 50%; transform: translateY(-50%); background: none; border: none; color: #fff; font-size: 1.4rem; cursor: pointer; padding: 4px 8px; opacity: 0.8; }
.lb-reward-close:hover { opacity: 1; }

/* ---- Paper Generator SVG Diagrams ---- */
.pg-pattern-svg { margin: 12px 0; overflow-x: auto; }
.pg-pattern-svg svg { max-width: 100%; height: auto; display: block; }

/* ---- Personalized Recommendations ---- */
.pg-rec-section { margin-top: 28px; }
.pg-rec-section h3 { margin-bottom: 14px; }
.pg-rec-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 14px; margin-bottom: 20px; }
.pg-rec-card {
    background: var(--card, #fff); border-radius: 12px; padding: 16px 18px;
    border: 1px solid var(--border); border-left: 4px solid var(--error);
    transition: box-shadow 0.2s;
}
.pg-rec-card:hover { box-shadow: 0 4px 16px rgba(0,0,0,0.08); }
.pg-rec-card-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 10px; }
.pg-rec-topic { font-weight: 700; font-size: 1rem; }
.pg-rec-score { font-size: 0.82rem; font-weight: 600; color: var(--error); background: rgba(239,68,68,0.1); padding: 2px 8px; border-radius: 6px; }
.pg-rec-actions { display: flex; flex-wrap: wrap; gap: 8px; }
.pg-rec-activity {
    padding: 6px 14px; border-radius: 8px; border: none; font-size: 0.82rem; font-weight: 600;
    background: var(--primary); color: #fff; cursor: pointer; transition: opacity 0.2s;
}
.pg-rec-activity:hover { opacity: 0.85; }
.pg-rec-lesson {
    padding: 6px 14px; border-radius: 8px; border: 2px solid var(--primary); font-size: 0.82rem;
    font-weight: 600; background: transparent; color: var(--primary); cursor: pointer; transition: all 0.2s;
}
.pg-rec-lesson:hover { background: var(--primary); color: #fff; }
.pg-rec-cw-section { margin-top: 16px; }
.pg-rec-cw-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 10px; }
.pg-rec-cw-card {
    background: var(--card, #fff); border-radius: 10px; padding: 12px 16px;
    border: 1px solid var(--border); display: flex; flex-direction: column; gap: 4px;
}
.pg-rec-cw-header { display: flex; justify-content: space-between; align-items: center; }
.pg-rec-cw-name { font-weight: 700; font-size: 0.9rem; }
.pg-rec-cw-score { font-size: 0.78rem; font-weight: 600; color: var(--error); }
.pg-rec-cw-tip { font-size: 0.82rem; color: var(--text-light); line-height: 1.4; }
.pg-rec-perfect {
    background: var(--card, #fff); border-radius: 12px; padding: 20px;
    border: 1px solid var(--border); border-left: 4px solid var(--success);
    text-align: center;
}
.pg-rec-perfect-icon { font-size: 2rem; margin-bottom: 6px; }
.pg-rec-perfect-title { font-weight: 700; font-size: 1.05rem; color: var(--success); }
.pg-rec-perfect-text { font-size: 0.9rem; color: var(--text-light); margin-top: 4px; }
/* Dark mode */
body.dark-mode .pg-rec-card { background: var(--card); }
body.dark-mode .pg-rec-cw-card { background: var(--card); }
body.dark-mode .pg-rec-perfect { background: var(--card); }
/* Glassmorphism */
body.has-bg .pg-rec-card,
body.has-bg .pg-rec-cw-card,
body.has-bg .pg-rec-perfect {
    background: rgba(255,255,255,0.85); backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px);
}
body.has-bg.dark-mode .pg-rec-card,
body.has-bg.dark-mode .pg-rec-cw-card,
body.has-bg.dark-mode .pg-rec-perfect {
    background: rgba(22,33,62,0.85); backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px);
}

/* ---- Ordering & Matching Question Types ---- */
.pg-ordering-area { margin-top: 12px; }
.pg-ordering-label { font-size: 0.88rem; font-weight: 600; color: var(--text-light); margin-bottom: 10px; }
.pg-ordering-selected { min-height: 40px; padding: 8px; border: 2px dashed var(--border, #e0e0e0); border-radius: 10px; margin-bottom: 10px; display: flex; flex-wrap: wrap; gap: 6px; }
.pg-order-tag {
    display: inline-block; padding: 6px 14px; border-radius: 8px; font-size: 0.85rem; font-weight: 600;
    background: var(--primary); color: #fff; cursor: pointer; transition: opacity 0.2s;
}
.pg-order-tag:hover { opacity: 0.8; }
.pg-ordering-pool { display: flex; flex-wrap: wrap; gap: 8px; }
.pg-order-item {
    padding: 8px 16px; border-radius: 8px; border: 2px solid var(--primary, #4361ee); font-size: 0.85rem;
    font-weight: 600; background: transparent; color: var(--primary, #4361ee); cursor: pointer; transition: all 0.2s;
}
.pg-order-item:hover:not(:disabled) { background: var(--primary); color: #fff; }
.pg-order-item.used, .pg-order-item:disabled { opacity: 0.35; cursor: default; }
.pg-ordering-feedback { margin-top: 8px; }
.pg-order-fb-row { padding: 4px 0; font-size: 0.88rem; }

.pg-matching-area { margin-top: 12px; }
.pg-match-row {
    display: flex; align-items: center; gap: 12px; padding: 10px 14px; margin-bottom: 6px;
    background: var(--card, #fff); border-radius: 10px; border: 1px solid var(--border, #e0e0e0);
    transition: border-color 0.2s;
}
.pg-match-row.pg-match-correct { border-color: var(--success, #22c55e); background: rgba(34,197,94,0.06); }
.pg-match-row.pg-match-incorrect { border-color: var(--error, #ef4444); background: rgba(239,68,68,0.06); }
.pg-match-left { font-weight: 600; font-size: 0.9rem; flex: 1; min-width: 0; }
.pg-match-select {
    padding: 6px 12px; border-radius: 8px; border: 1.5px solid var(--border, #e0e0e0); font-size: 0.85rem;
    font-family: inherit; background: var(--bg, #fff); color: var(--text, #1a1a2e); min-width: 160px;
}
.pg-match-select:focus { border-color: var(--primary); outline: none; }
.pg-matching-feedback { margin-top: 8px; }
.pg-match-fb-row { padding: 4px 0; font-size: 0.88rem; }
body.dark-mode .pg-match-select { background: #1a1a2e; border-color: #444; color: #e0e0e0; }
body.dark-mode .pg-match-row { background: var(--card); }
body.dark-mode .pg-ordering-selected { border-color: #444; }

/* ---- PhET Simulation Iframe Embed ---- */
.pg-sim-embed { position: relative; width: 100%; margin: 12px 0 16px; border-radius: var(--radius, 12px); overflow: hidden; box-shadow: 0 4px 20px rgba(0,0,0,0.15); }
.pg-sim-embed iframe { width: 100%; height: 450px; border: none; display: block; background: #1a1a2e; }
.pg-sim-label { font-size: 0.82rem; font-weight: 600; color: var(--text-light); margin-bottom: 6px; }
.pg-sim-fallback { display: none; padding: 20px; text-align: center; background: #1a1a2e; color: #e0e0e0; border-radius: var(--radius, 12px); }
.pg-sim-fallback a { color: var(--primary); font-weight: 600; }

/* ---- Video Embed in Paper Generator ---- */
.pg-video-embed { position: relative; width: 100%; padding-bottom: 56.25%; margin: 12px 0 16px; border-radius: var(--radius, 12px); overflow: hidden; box-shadow: 0 4px 20px rgba(0,0,0,0.15); }
.pg-video-embed iframe { position: absolute; top: 0; left: 0; width: 100%; height: 100%; border: none; }

/* ---- PhET Simulation Embeds ---- */
.lesson-sim-desc {
    color: var(--text-light); font-size: 0.92rem; margin-bottom: 12px; line-height: 1.5;
}
.lesson-sim-container {
    position: relative; width: 100%; border-radius: var(--radius);
    overflow: hidden; margin: 12px 0 16px; box-shadow: 0 4px 20px rgba(0,0,0,0.15);
    background: #1a1a2e;
}
.lesson-sim-card {
    padding: 32px 24px; text-align: center; color: #e0e0e0;
}
.lesson-sim-icon { font-size: 2.5rem; margin-bottom: 10px; }
.lesson-sim-card p { font-size: 0.9rem; margin-bottom: 16px; opacity: 0.85; }
.lesson-sim-launch {
    display: inline-block; padding: 10px 24px; font-size: 0.9rem; font-weight: 700;
    border-radius: 10px; text-decoration: none;
}
.lesson-sim-tasks {
    background: rgba(128,128,128,0.06); border-radius: 10px; padding: 14px 18px;
    margin-top: 8px; font-size: 0.88rem; line-height: 1.6;
}
.lesson-sim-tasks strong { color: var(--primary); }
.lesson-sim-tasks ul { margin: 6px 0 0 16px; padding: 0; }
.lesson-sim-tasks li { margin-bottom: 4px; }

/* ---- Home icon ---- */
.home-icon { flex-shrink: 0; }

/* ---- Search ---- */
.search-bar { position: relative; margin: 0 auto 18px; max-width: 480px; }
.search-input { width: 100%; padding: 10px 16px; border: 1.5px solid var(--border, #e0e0e0); border-radius: 10px; font-size: 0.92rem; font-family: inherit; background: var(--bg, #fff); color: var(--text, #1a1a2e); outline: none; transition: border-color 0.2s; }
.search-input:focus { border-color: var(--primary, #4361ee); }
.search-input::placeholder { color: var(--text-light, #6c757d); opacity: 0.7; }
body.dark-mode .search-input { background: #1a1a2e; border-color: #444; color: #e0e0e0; }
.search-results { position: absolute; top: 100%; left: 0; right: 0; background: var(--bg, #fff); border: 1.5px solid var(--border, #e0e0e0); border-radius: 10px; margin-top: 4px; max-height: 320px; overflow-y: auto; z-index: 100; display: none; box-shadow: 0 8px 24px rgba(0,0,0,0.12); }
.search-results.show { display: block; }
.search-result { display: flex; align-items: center; gap: 10px; padding: 10px 14px; cursor: pointer; border-bottom: 1px solid rgba(0,0,0,0.05); transition: background 0.15s; }
.search-result:hover, .search-result.active { background: var(--primary-light, rgba(67,97,238,0.08)); }
.search-result:last-child { border-bottom: none; }
.search-result-icon { font-size: 1.2rem; flex-shrink: 0; }
.search-result-text { flex: 1; min-width: 0; }
.search-result-title { font-weight: 600; font-size: 0.88rem; }
.search-result-sub { font-size: 0.75rem; color: var(--text-light, #6c757d); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.search-result-type { font-size: 0.65rem; text-transform: uppercase; font-weight: 700; padding: 2px 6px; border-radius: 4px; background: var(--primary-light, rgba(67,97,238,0.1)); color: var(--primary, #4361ee); flex-shrink: 0; }
body.dark-mode .search-results { background: #16213e; border-color: #444; }
.topic-card.search-hidden { display: none !important; }

/* ---- Lesson History Modal ---- */
.lh-overlay { position: fixed; inset: 0; background: rgba(0,0,0,0.5); z-index: 9999; display: flex; align-items: center; justify-content: center; backdrop-filter: blur(4px); -webkit-backdrop-filter: blur(4px); }
.lh-modal { background: var(--bg, #fff); border-radius: 16px; width: 90%; max-width: 520px; max-height: 80vh; overflow: hidden; display: flex; flex-direction: column; box-shadow: 0 16px 48px rgba(0,0,0,0.2); }
.lh-header { display: flex; align-items: center; justify-content: space-between; padding: 16px 20px; border-bottom: 1px solid var(--border, #e0e0e0); }
.lh-header h2 { margin: 0; font-size: 1.1rem; }
.lh-close { background: none; border: none; font-size: 1.5rem; cursor: pointer; color: var(--text-light, #6c757d); padding: 0 4px; }
.lh-body { overflow-y: auto; padding: 16px 20px; flex: 1; }
.lh-count { font-size: 0.8rem; color: var(--text-light, #6c757d); margin-bottom: 12px; }
.lh-row { display: flex; align-items: center; justify-content: space-between; padding: 12px 14px; background: var(--card, #fff); border-radius: 12px; box-shadow: 0 2px 8px rgba(0,0,0,0.06); margin-bottom: 8px; }
.lh-row:last-child { margin-bottom: 0; }
.lh-info { flex: 1; min-width: 0; }
.lh-name { font-weight: 600; font-size: 0.88rem; }
.lh-date { font-size: 0.72rem; color: var(--text-light, #6c757d); }
.lh-score-area { text-align: right; min-width: 100px; }
.lh-bar-wrap { width: 80px; height: 6px; background: var(--border, #e0e0e0); border-radius: 3px; margin-bottom: 4px; margin-left: auto; }
.lh-bar { height: 100%; border-radius: 3px; transition: width 0.3s; }
.lh-pct { font-size: 0.75rem; font-weight: 600; }
body.dark-mode .lh-modal { background: #16213e; }

/* ---- Paper Generator Folder Nav ---- */
.pg-nav-folders { display: flex; flex-wrap: wrap; gap: 4px; padding: 8px 0; align-items: flex-start; }
.pg-nav-q { display: inline-flex; flex-direction: column; align-items: center; position: relative; }
.pg-nav-qbtn { padding: 6px 12px; border: 1.5px solid var(--border, #e0e0e0); border-radius: 8px; background: var(--bg, #fff); color: var(--text, #1a1a2e); font-size: 0.82rem; font-weight: 600; cursor: pointer; transition: all 0.15s; }
.pg-nav-qbtn:hover { border-color: var(--primary, #4361ee); }
.pg-nav-qbtn.active { background: var(--primary, #4361ee); color: #fff; border-color: var(--primary, #4361ee); }
.pg-nav-qbtn.has-answered { border-color: #27ae60; }
.pg-nav-parts { display: none; flex-wrap: wrap; gap: 2px; margin-top: 4px; }
.pg-nav-q.expanded .pg-nav-parts { display: flex; }
.pg-nav-pbtn { padding: 3px 8px; border: 1px solid var(--border, #e0e0e0); border-radius: 6px; background: transparent; color: var(--text, #1a1a2e); font-size: 0.75rem; cursor: pointer; transition: all 0.15s; }
.pg-nav-pbtn:hover { border-color: var(--primary, #4361ee); }
.pg-nav-pbtn.active { background: var(--primary, #4361ee); color: #fff; border-color: var(--primary, #4361ee); }
.pg-nav-pbtn.answered { border-color: #27ae60; color: #27ae60; }
.pg-nav-pbtn.correct { background: rgba(39,174,96,0.1); border-color: #27ae60; color: #27ae60; }
.pg-nav-pbtn.incorrect { background: rgba(231,76,60,0.1); border-color: var(--error); color: var(--error); }
body.dark-mode .pg-nav-qbtn { background: #1a1a2e; border-color: #444; color: #e0e0e0; }
body.dark-mode .pg-nav-pbtn { border-color: #444; color: #e0e0e0; }

/* ---- Streak Freeze Dialog ---- */
.freeze-dialog-overlay {
    display: none; position: fixed; inset: 0; z-index: 9000;
    background: rgba(0,0,0,0.5); justify-content: center; align-items: center;
}
.freeze-dialog-overlay.show { display: flex; }
.freeze-dialog {
    background: var(--card); border-radius: var(--radius);
    box-shadow: 0 8px 40px rgba(0,0,0,0.3); padding: 28px 24px;
    text-align: center; max-width: 380px; width: 92%;
    animation: slideIn 0.3s ease; position: relative;
}
.freeze-dialog h2 { color: #60a5fa; margin-bottom: 8px; font-size: 1.4rem; }
.freeze-dialog-desc { color: var(--text-light); font-size: 0.88rem; margin-bottom: 20px; line-height: 1.5; }
.freeze-dialog-close {
    position: absolute; top: 10px; right: 14px; background: none;
    border: none; font-size: 1.6rem; color: var(--text-light); cursor: pointer; padding: 4px;
}
.freeze-dialog-close:hover { color: var(--error); }
.freeze-dialog-dots { display: flex; justify-content: center; gap: 10px; margin-bottom: 8px; }
.freeze-dialog-dots .freeze-dot { width: 28px; height: 28px; border-width: 3px; }
.freeze-dialog-count { font-size: 0.85rem; color: var(--text-light); margin-bottom: 16px; }
.freeze-dialog-balance {
    font-size: 1.1rem; font-weight: 700; margin-bottom: 12px;
    display: flex; align-items: center; justify-content: center; gap: 6px;
}
.freeze-dialog-gem-icon { color: #a855f7; font-size: 1.2rem; }
.freeze-dialog-buy { width: 100%; padding: 14px; font-size: 0.95rem; }
.freeze-dialog-buy:disabled { background: #666; cursor: default; transform: none; }
.freeze-dialog-msg {
    font-size: 0.82rem; min-height: 1.2em; margin-top: 8px;
    transition: color 0.3s;
}
.freeze-dialog-msg.error { color: var(--error); }
.freeze-dialog-msg.success { color: var(--success); }
.freeze-dialog-info {
    font-size: 0.75rem; color: var(--text-light); margin-top: 12px; opacity: 0.7;
}

/* ---- Gem Shop ---- */
.gem-shop-overlay {
    display: none; position: fixed; inset: 0; z-index: 9000;
    background: rgba(0,0,0,0.5); justify-content: center; align-items: center;
}
.gem-shop-overlay.show { display: flex; }
.gem-shop {
    background: var(--card); border-radius: var(--radius);
    box-shadow: 0 8px 40px rgba(0,0,0,0.3); padding: 28px 24px;
    text-align: center; max-width: 420px; width: 92%;
    max-height: 85vh; overflow-y: auto;
    animation: slideIn 0.3s ease; position: relative;
}
.gem-shop h2 { color: #a855f7; margin-bottom: 4px; font-size: 1.4rem; }
.gem-shop-close {
    position: absolute; top: 10px; right: 14px; background: none;
    border: none; font-size: 1.6rem; color: var(--text-light); cursor: pointer; padding: 4px;
}
.gem-shop-close:hover { color: var(--error); }
.gem-shop-balance {
    font-size: 1.2rem; font-weight: 700; margin-bottom: 16px;
    display: flex; align-items: center; justify-content: center; gap: 6px;
}
.gem-shop-gem-icon { color: #a855f7; font-size: 1.3rem; }
.gem-shop-section { text-align: left; margin-bottom: 16px; }
.gem-shop-section h3 {
    font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.06em;
    color: var(--text-light); margin-bottom: 8px; padding-bottom: 4px;
    border-bottom: 1px solid rgba(128,128,128,0.2);
}
.gem-mission {
    display: flex; align-items: center; gap: 10px;
    padding: 10px 12px; border-radius: 10px; margin-bottom: 6px;
    background: rgba(128,128,128,0.06); transition: background 0.2s;
}
.gem-mission.ready { background: rgba(168,85,247,0.08); }
.gem-mission.claimed { opacity: 0.5; }
.gem-mission-info { flex: 1; min-width: 0; }
.gem-mission-title { font-weight: 600; font-size: 0.9rem; }
.gem-mission-desc { font-size: 0.78rem; color: var(--text-light); }
.gem-mission-reward {
    font-weight: 700; font-size: 0.95rem; color: #a855f7;
    white-space: nowrap; min-width: 32px; text-align: right;
}
.gem-mission-reward::after { content: 'g'; font-size: 0.7rem; margin-left: 1px; }
.gem-mission-claim { white-space: nowrap; padding: 6px 14px !important; font-size: 0.78rem !important; }
.gem-mission-badge {
    font-size: 0.72rem; font-weight: 600; padding: 4px 10px; border-radius: 10px;
    background: var(--success-light); color: var(--success); white-space: nowrap;
}
.gem-mission-badge.pending { background: rgba(128,128,128,0.1); color: var(--text-light); }
.gem-shop-info {
    font-size: 0.78rem; color: var(--text-light); margin-top: 8px;
    border-top: 1px solid rgba(128,128,128,0.2); padding-top: 12px;
}

/* ---- High Contrast ---- */
body.high-contrast .topic-card,
body.high-contrast .question-card,
body.high-contrast .score-bar,
body.high-contrast .search-input,
body.high-contrast .search-results,
body.high-contrast header {
    border: 2px solid var(--text) !important;
    overflow: hidden;
    position: relative;
}
body.high-contrast .topic-tag { border: 1.5px solid currentColor; }
body.high-contrast .btn, body.high-contrast .btn-primary, body.high-contrast .btn-hint {
    border: 2px solid currentColor !important;
}
body.high-contrast .option-btn { border: 2px solid var(--text) !important; }

/* ---- Two-Column Folder Layout ---- */
.folder-layout {
    display: grid;
    grid-template-columns: 220px 1fr;
    gap: 20px;
    align-items: start;
}
.folder-sidebar {
    position: sticky; top: 72px;
    display: flex; flex-direction: column; gap: 2px;
}
.folder-sidebar-item {
    display: flex; align-items: center; gap: 8px;
    padding: 10px 12px; border-radius: 10px;
    font-size: 13px; font-weight: 500; color: var(--text);
    cursor: pointer; transition: background 0.12s;
    border: none; background: none; text-align: left;
    font-family: inherit; width: 100%;
}
.folder-sidebar-item:hover { background: rgba(0,0,0,0.04); }
.folder-sidebar-item.active {
    background: var(--primary-light); color: var(--primary); font-weight: 600;
}
.folder-sidebar-item .sidebar-tag {
    font-size: 10px; padding: 2px 6px; border-radius: 8px;
    background: var(--primary-light); color: var(--primary);
    margin-left: auto; font-weight: 600;
}
.folder-sidebar-item .sidebar-tag.lesson-tag {
    background: #e0f7fa; color: #00838f;
}
body.dark-mode .folder-sidebar-item:hover { background: rgba(255,255,255,0.05); }
body.dark-mode .folder-sidebar-item.active { background: rgba(67,97,238,0.15); }

.folder-main { min-width: 0; }

/* ---- Subject Exam Banner (persistent across pages) ---- */
.subject-exam-banner {
    display: flex; align-items: center; justify-content: space-between;
    background: #EEEDFE; border: 0.5px solid #AFA9EC;
    border-radius: 10px; padding: 10px 14px; margin-bottom: 16px;
    gap: 10px;
}
.subject-exam-banner-left { display: flex; align-items: center; gap: 8px; }
.subject-exam-banner-icon {
    width: 24px; height: 24px; border-radius: 6px; background: #AFA9EC;
    display: flex; align-items: center; justify-content: center;
    font-size: 12px; flex-shrink: 0;
}
.subject-exam-banner-text { font-size: 12px; font-weight: 500; color: #3C3489; }
.subject-exam-banner-days {
    font-size: 16px; font-weight: 600; color: #3C3489;
    white-space: nowrap;
}
body.dark-mode .subject-exam-banner {
    background: rgba(83,74,183,0.12); border-color: rgba(175,169,236,0.3);
}
body.dark-mode .subject-exam-banner-text { color: #c4bff0; }
body.dark-mode .subject-exam-banner-days { color: #d4d0f4; }
body.dark-mode .subject-exam-banner-icon { background: rgba(175,169,236,0.3); }

/* ---- Full-Focus Practice Mode ---- */
body.focus-mode .hub-header,
body.focus-mode .auth-bar,
body.focus-mode .daily-streak-bar,
body.focus-mode .last-updated,
body.focus-mode .search-bar,
body.focus-mode .continue-prompt,
body.focus-mode .level-section,
body.focus-mode .subject-exam-banner,
body.focus-mode .sidebar,
body.focus-mode .sidebar-toggle,
body.focus-mode .fb-float-btn,
body.focus-mode .fb-float-panel,
body.focus-mode .calc-btn,
body.focus-mode .calc-modal,
body.focus-mode .rules-ref,
body.focus-mode .workout-section,
body.focus-mode .hint-box,
body.focus-mode .btn-hint,
body.focus-mode .music-btn,
body.focus-mode footer { display: none !important; }

body.focus-mode { padding: 0 !important; }
body.focus-mode #app { max-width: 600px; padding: 12px 16px; }

body.focus-mode .view.active > header {
    display: none;
}

.focus-topbar {
    display: none;
    position: sticky; top: 0; z-index: 1000;
    align-items: center; justify-content: space-between;
    height: 48px; padding: 0 16px;
    background: var(--card); border-bottom: 0.5px solid var(--border);
}
body.focus-mode .focus-topbar { display: flex; }
body.dark-mode .focus-topbar { background: var(--card); border-bottom-color: rgba(255,255,255,0.06); }

.focus-exit {
    display: inline-flex; align-items: center; gap: 4px;
    font-size: 13px; font-weight: 500; color: var(--text-light);
    background: none; border: none; cursor: pointer;
    padding: 6px 10px; border-radius: 8px;
    font-family: inherit; transition: background 0.12s;
}
.focus-exit:hover { background: rgba(0,0,0,0.04); }
body.dark-mode .focus-exit:hover { background: rgba(255,255,255,0.05); }

.focus-counter {
    font-size: 13px; font-weight: 600; color: var(--text);
}
.focus-progress {
    width: 120px; height: 4px; background: var(--border);
    border-radius: 2px; overflow: hidden;
}
.focus-progress-fill {
    height: 100%; background: var(--primary); border-radius: 2px;
    transition: width 0.3s ease;
}

/* ---- Responsive ---- */
@media (max-width: 600px) {
    body { padding: 12px; }
    .topic-grid { grid-template-columns: 1fr; }
    .options-grid { grid-template-columns: 1fr; }
    .score-bar { gap: 16px; padding: 12px; }
    .question-card { padding: 20px 16px; }
    .hub-header h1 { font-size: 1.5rem; }
    .lesson-content { padding: 20px 16px; }
    .fb-float-btn { bottom: 16px; right: 76px; width: 42px; height: 42px; font-size: 1rem; }
    .fb-float-panel { width: calc(100vw - 32px); right: 16px; bottom: 68px; }
    .dash-overview { flex-direction: column; align-items: stretch; }
    .dash-row-label { min-width: 80px; font-size: 0.78rem; }
    .pg-nav-strip { gap: 3px; padding: 8px; }
    .pg-nav-btn { padding: 3px 6px; font-size: 0.65rem; }
    .pg-context-box { padding: 14px 16px; }
    .pg-mode-select { flex-direction: column; align-items: stretch; }
    .pg-option-row { flex-direction: column; gap: 6px; }
    .pg-cw-grid { grid-template-columns: 1fr 1fr; }
    .pg-results-summary { gap: 12px; }
    .pg-bottom-nav { flex-wrap: wrap; }
    .pg-rec-grid { grid-template-columns: 1fr; }
    .pg-rec-cw-grid { grid-template-columns: 1fr; }
    /* Collapse folder layout to single column on mobile */
    .folder-layout { grid-template-columns: 1fr; }
    .folder-sidebar {
        position: static;
        flex-direction: row; overflow-x: auto;
        gap: 4px; padding-bottom: 4px;
        -webkit-overflow-scrolling: touch;
        scrollbar-width: none;
    }
    .folder-sidebar::-webkit-scrollbar { display: none; }
    .folder-sidebar-item {
        white-space: nowrap; padding: 8px 14px;
        border-radius: 20px; font-size: 12px;
        border: 1px solid var(--border); flex-shrink: 0;
    }
    .folder-sidebar-item.active {
        border-color: var(--primary);
    }
}

/* ---- 375px Mobile Audit ---- */
@media (max-width: 375px) {
    body { padding: 8px; }
    #app { max-width: 100%; }
    .hub-header h1 { font-size: 1.3rem; }
    .hub-header p { font-size: 0.82rem; }
    .topic-card { padding: 18px 14px; }
    .topic-card h2 { font-size: 0.95rem; }
    .topic-card p { font-size: 0.78rem; }
    .topic-card-inner { gap: 10px; }
    .topic-card-icon { width: 36px; height: 36px; }
    .score-bar { gap: 12px; padding: 10px; flex-wrap: wrap; }
    .score-item .value { font-size: 1.1rem; }
    .score-item .label { font-size: 0.68rem; }
    .question-card { padding: 16px 12px; }
    .question-text { font-size: 0.92rem; }
    .question-prompt { font-size: 1.1rem; }
    .option-btn { padding: 12px; font-size: 0.85rem; min-height: 44px; }
    .options-grid { gap: 8px; }
    .btn { padding: 10px 20px; font-size: 0.88rem; min-height: 44px; }
    .level-btn { padding: 8px 14px; font-size: 0.78rem; }
    .level-select { gap: 6px; flex-wrap: wrap; }
    .back-btn { font-size: 0.82rem; padding: 7px 12px; }
    .lesson-content { padding: 16px 12px; }
    .lesson-box { padding: 12px 14px; font-size: 0.88rem; }
    .hint-box { padding: 10px 14px; font-size: 0.85rem; }
    .feedback { padding: 14px; }
    .feedback-title { font-size: 1rem; }
    .feedback-explanation { font-size: 0.85rem; }
    .rules-ref summary { padding: 12px 16px; font-size: 0.88rem; }
    .rules-content { padding: 0 16px 14px; }
    .rule-item { font-size: 0.88rem; }
    .auth-bar { gap: 6px; flex-wrap: wrap; }
    .daily-streak-bar { gap: 14px; flex-wrap: wrap; }
    .daily-streak-val { font-size: 1.2rem; }
    .subject-exam-banner { padding: 8px 10px; border-radius: 8px; }
    .subject-exam-banner-text { font-size: 11px; }
    .subject-exam-banner-days { font-size: 14px; }
    .focus-topbar { height: 44px; padding: 0 10px; }
    .focus-progress { width: 80px; }
    .folder-sidebar-item { padding: 6px 10px; font-size: 11px; }
    .calc-modal { width: calc(100vw - 16px); right: 8px; }
}

/* ---- Empty States ---- */
.empty-state {
    display: flex; flex-direction: column; align-items: center;
    justify-content: center; gap: 8px;
    padding: 32px 20px; text-align: center;
    color: var(--text-light);
}
.empty-state-icon {
    font-size: 32px; opacity: 0.4; line-height: 1;
}
.empty-state-title {
    font-size: 14px; font-weight: 600; color: var(--text);
}
.empty-state-desc {
    font-size: 12px; color: var(--text-light); max-width: 280px;
    line-height: 1.5;
}
.empty-state-action {
    margin-top: 8px; padding: 8px 20px; border-radius: 10px;
    background: var(--primary); color: #fff; border: none;
    font-size: 13px; font-weight: 600; cursor: pointer;
    text-decoration: none; display: inline-block;
    transition: filter 0.15s;
}
.empty-state-action:hover { filter: brightness(1.08); }

/* Score bar empty state */
.score-bar:empty::after {
    content: 'Answer a question to see your stats';
    display: block; width: 100%; text-align: center;
    font-size: 12px; color: var(--text-light); padding: 8px;
}

/* ---- Keyboard Navigation for Practice ---- */
.option-btn:focus-visible {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
    box-shadow: 0 0 0 4px rgba(67, 97, 238, 0.15);
}
.option-btn[data-key]::after {
    content: attr(data-key);
    position: absolute; top: 4px; right: 6px;
    font-size: 9px; font-weight: 700; color: var(--text-light);
    opacity: 0.5; pointer-events: none;
    background: var(--bg-subtle); padding: 1px 5px;
    border-radius: 4px; line-height: 1.3;
}
.option-btn { position: relative; }

/* Next button keyboard hint */
.next-btn:focus-visible {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}

/* ---- Touch & Mobile Improvements ---- */
* { -webkit-tap-highlight-color: transparent; }

.btn-primary:active { filter: brightness(0.9); }
.option-btn:active:not(:disabled) { transform: scale(0.98); }
.topic-card:active { transform: translateY(0); }
.back-btn:active { background: var(--primary-light); }

@media (pointer: coarse) {
    .btn-sm { padding: 10px 18px; font-size: 0.85rem; min-height: 44px; }
    .pg-nav-btn { min-width: 40px; min-height: 36px; padding: 6px 10px; }
    .level-btn, .mode-btn { padding: 10px 20px; min-height: 44px; }
}

@media (hover: none) {
    .topic-card:hover { transform: none; }
    .btn-primary:hover { transform: none; }
}

@media (pointer: coarse) {
    #view-paper-active { position: relative; }
    #view-paper-active::before, #view-paper-active::after {
        content: ''; position: fixed; top: 50%; width: 4px; height: 60px;
        border-radius: 2px; background: var(--primary); opacity: 0.15;
        transform: translateY(-50%); pointer-events: none;
    }
    #view-paper-active::before { left: 4px; }
    #view-paper-active::after { right: 4px; }
}

/* ================================================================
   PAPER GENERATOR ENHANCEMENTS — Feedback Items #4-#13
   ================================================================ */

/* ---- #5 Bookmark / Flag ---- */
.pg-flag-btn {
    background: none; border: none; font-size: 1.1rem; cursor: pointer;
    padding: 2px 6px; opacity: 0.35; transition: all 0.2s; color: var(--text, #2b2d42);
}
.pg-flag-btn:hover { opacity: 0.7; }
.pg-flag-btn.flagged { opacity: 1; color: #f39c12; }
.pg-nav-pbtn.flagged { position: relative; }
.pg-nav-pbtn.flagged::after {
    content: ''; position: absolute; top: -2px; right: -2px;
    width: 7px; height: 7px; border-radius: 50%;
    background: #f39c12; border: 1px solid #fff;
}
.pg-flag-count { font-size: 0.78rem; color: #f39c12; font-weight: 600; margin-left: 8px; }

/* ---- #7 Per-Q Marks in Nav ---- */
.pg-nav-q-marks {
    font-size: 0.65rem; color: var(--text-light, #6c757d); font-weight: 600;
    display: block; text-align: center; margin-top: 1px;
}

/* ---- #10 Topic Pool Info ---- */
.pg-pool-info { margin-top: 12px; }
.pg-pool-info summary {
    font-size: 0.82rem; font-weight: 600; color: var(--primary);
    cursor: pointer; padding: 6px 0;
}
.pg-pool-grid { padding: 8px 0; }
.pg-pool-row {
    display: flex; justify-content: space-between; align-items: center;
    padding: 4px 8px; font-size: 0.82rem;
    border-bottom: 1px solid var(--border-light, #f0f0f0);
}
.pg-pool-row:last-child { border-bottom: none; }
.pg-pool-topic { font-weight: 600; text-transform: capitalize; }
.pg-pool-count { color: var(--text-light); font-size: 0.78rem; }

/* ---- #11 Resume Banner ---- */
.pg-resume-banner {
    display: flex; align-items: center; justify-content: space-between;
    background: linear-gradient(135deg, rgba(67,97,238,0.08), rgba(67,97,238,0.15));
    border: 1.5px solid var(--primary, #4361ee);
    border-radius: 12px; padding: 14px 18px; margin-bottom: 16px;
    gap: 12px; flex-wrap: wrap;
}
.pg-resume-info { flex: 1; min-width: 0; }
.pg-resume-info strong { display: block; font-size: 0.92rem; margin-bottom: 2px; }
.pg-resume-meta { font-size: 0.78rem; color: var(--text-light); }
.pg-resume-actions { display: flex; gap: 8px; }
body.dark-mode .pg-resume-banner {
    background: linear-gradient(135deg, rgba(67,97,238,0.1), rgba(67,97,238,0.05));
}

/* ---- #12 Time Adjustment Buttons ---- */
.pg-time-adjust {
    display: inline-flex; align-items: center; gap: 4px; margin-left: 6px;
}
.pg-time-btn {
    width: 26px; height: 26px; border-radius: 50%; border: 1.5px solid var(--border, #e0e0e0);
    background: var(--card, #fff); color: var(--text); font-size: 0.9rem; font-weight: 700;
    cursor: pointer; display: flex; align-items: center; justify-content: center;
    transition: all 0.15s; padding: 0; line-height: 1;
}
.pg-time-btn:hover { border-color: var(--primary); color: var(--primary); }
body.dark-mode .pg-time-btn { background: #1a1a2e; border-color: #444; }

/* ---- #13 Sticky Context Box ---- */
.pg-context-box.pg-sticky {
    position: sticky; top: 0; z-index: 10;
    max-height: 45vh; overflow-y: auto;
    background: var(--card, #fff);
    border-bottom: 1px solid var(--border, #e0e0e0);
    border-radius: 0 0 var(--radius, 12px) var(--radius, 12px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.08);
    padding: 12px 16px;
}
body.dark-mode .pg-context-box.pg-sticky { background: var(--card); border-bottom-color: #444; }
body.has-bg .pg-context-box.pg-sticky { background: rgba(255,255,255,0.95); backdrop-filter: blur(12px); }
body.has-bg.dark-mode .pg-context-box.pg-sticky { background: rgba(22,33,62,0.95); }

/* ---- #4 Formatting Polish ---- */
.pg-part-card-wrap { transition: opacity 0.25s ease; }
.pg-part-card-wrap.pg-fade-in { animation: pgFadeIn 0.3s ease; }
@keyframes pgFadeIn { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: translateY(0); } }
.pg-context-title {
    font-size: 0.92rem; font-weight: 700; margin-bottom: 8px;
    display: flex; align-items: center; gap: 8px; flex-wrap: wrap;
}
.pg-topic-label {
    display: inline-block; padding: 2px 10px; border-radius: 8px;
    background: var(--primary-light, rgba(67,97,238,0.1));
    color: var(--primary); font-size: 0.72rem; font-weight: 700;
    text-transform: uppercase; letter-spacing: 0.3px;
}
.pg-context-box {
    background: var(--card, #fff); border-radius: var(--radius, 12px);
    box-shadow: var(--shadow); padding: 16px 20px; margin-bottom: 16px;
}
.pg-context-box .pg-context-text { line-height: 1.6; }
.pg-context-box svg { max-width: 100%; height: auto; display: block; margin: 8px auto; }
.pg-grade-circle {
    display: inline-flex; flex-direction: column; align-items: center; justify-content: center;
    width: 90px; height: 90px; border-radius: 50%;
    background: var(--primary); margin-bottom: 16px;
    box-shadow: 0 4px 20px rgba(67,97,238,0.3);
}
.pg-feedback.show { animation: pgFadeIn 0.3s ease; }
.pg-q-breakdown { transition: box-shadow 0.2s; }
.pg-q-breakdown:hover { box-shadow: 0 4px 16px rgba(0,0,0,0.1); }

/* ---- #1 Interactive Labels (overlay) ---- */
.pg-label-overlay { position: relative; display: inline-block; }
.pg-label-pin {
    position: absolute; padding: 3px 8px; border-radius: 6px;
    background: rgba(0,0,0,0.75); color: #fff; font-size: 0.7rem;
    font-weight: 600; pointer-events: none; white-space: nowrap;
    transform: translate(-50%, -120%);
}

/* ---- Measurement Question Type (#6 simplified) ---- */
.pg-measurement-area { text-align: center; margin: 12px 0; }
.pg-measurement-area svg { max-width: 100%; height: auto; }
.pg-measurement-hint { font-size: 0.78rem; color: var(--text-light); margin-top: 6px; }