/* ════════════════════════════════════════════════
   Multi-Video Exam
   ════════════════════════════════════════════════ */

/* ══════════════════════════════════════════════════════
   MULTI-VIDEO EXAM
   ══════════════════════════════════════════════════════ */
.mexam-page {
    position: fixed; inset: 0; z-index: 9700;
    background: #070712;
    display: flex; flex-direction: column;
    overflow: hidden;
}
html.light-mode .mexam-page { background: #eef0ff; }
.mexam-inner {
    display: flex; flex-direction: column;
    height: 100%; max-width: 900px;
    margin: 0 auto; width: 100%;
    padding: 0 20px;
    overflow-y: auto;
}
.mexam-header {
    display: flex; align-items: center;
    justify-content: space-between;
    padding: 16px 0; flex-shrink: 0;
}
.mexam-title {
    font-size: 22px; font-weight: 800;
    color: var(--text-primary);
}
.mexam-subtitle {
    font-size: 12px; color: var(--text-secondary);
    text-align: center;
}

/* Step container */
.mexam-step { padding: 10px 0 40px; }
.mexam-step.hidden { display: none; }

/* ── Step 1: Video Selector ── */
.mexam-select-header {
    display: flex; align-items: center;
    justify-content: space-between;
    margin-bottom: 16px;
}
.mexam-select-header h3 {
    font-size: 16px; font-weight: 700;
    color: var(--text-primary);
}
.mexam-selected-count {
    font-size: 13px; font-weight: 600;
    color: var(--accent); background: rgba(139,92,246,0.12);
    padding: 4px 12px; border-radius: 20px;
}
.mexam-video-list {
    display: flex; flex-direction: column;
    gap: 8px; max-height: 50vh;
    overflow-y: auto; padding-right: 4px;
}
.mexam-video-item {
    display: flex; align-items: center;
    gap: 12px; padding: 12px 14px;
    border-radius: 12px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    cursor: pointer; transition: all 0.2s;
}
.mexam-video-item:hover {
    border-color: var(--accent);
    background: var(--bg-card-hover);
}
.mexam-video-item.selected {
    border-color: var(--accent);
    background: rgba(139,92,246,0.08);
    box-shadow: 0 0 0 1px var(--accent);
}
.mexam-video-check {
    width: 22px; height: 22px; border-radius: 6px;
    border: 2px solid var(--border);
    display: flex; align-items: center;
    justify-content: center; flex-shrink: 0;
    transition: all 0.2s;
}
.mexam-video-item.selected .mexam-video-check {
    background: var(--accent);
    border-color: var(--accent);
}
.mexam-video-check svg { display: none; }
.mexam-video-item.selected .mexam-video-check svg { display: block; }
.mexam-video-thumb {
    width: 64px; height: 36px; border-radius: 6px;
    object-fit: cover; flex-shrink: 0;
}
.mexam-video-info { flex: 1; min-width: 0; }
.mexam-video-name {
    font-size: 13px; font-weight: 600;
    color: var(--text-primary);
    white-space: nowrap; overflow: hidden;
    text-overflow: ellipsis;
}
.mexam-video-meta {
    font-size: 11px; color: var(--text-secondary);
}
.mexam-video-topics {
    font-size: 10px; color: var(--text-muted);
    margin-top: 2px;
}

/* Options row */
.mexam-options-row {
    display: flex; align-items: center;
    justify-content: space-between;
    gap: 16px; margin-top: 20px;
    padding-top: 16px;
    border-top: 1px solid var(--border);
}
.mexam-slider-group {
    display: flex; align-items: center;
    gap: 10px; font-size: 13px;
    color: var(--text-secondary);
}
.mexam-slider-group input[type="range"] {
    width: 120px; accent-color: var(--accent);
}
.mexam-slider-val {
    font-weight: 700; color: var(--accent);
    min-width: 24px; text-align: center;
}
.mexam-generate-btn {
    display: flex; align-items: center;
    gap: 8px; padding: 12px 24px;
    border-radius: 12px; border: none;
    background: linear-gradient(135deg, var(--accent), var(--accent-dark));
    color: #fff; font-weight: 700;
    font-size: 14px; cursor: pointer;
    transition: all 0.25s;
    font-family: var(--font);
}
.mexam-generate-btn:hover:not(:disabled) {
    transform: translateY(-1px);
    box-shadow: 0 4px 20px rgba(139,92,246,0.4);
}
.mexam-generate-btn:disabled {
    opacity: 0.4; cursor: not-allowed;
}

/* ── Step 2: Loading ── */
.mexam-loading {
    display: flex; flex-direction: column;
    align-items: center; justify-content: center;
    padding: 80px 20px; gap: 16px;
}
.mexam-spinner {
    width: 48px; height: 48px;
    border: 3px solid var(--border);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }
.mexam-loading p {
    font-size: 16px; font-weight: 600;
    color: var(--text-primary);
}
.mexam-loading-hint {
    font-size: 12px !important; font-weight: 400 !important;
    color: var(--text-secondary) !important;
}

/* ── Step 3: Exam Questions ── */
.mexam-exam-header {
    display: flex; align-items: center;
    justify-content: space-between;
    margin-bottom: 12px;
}
.mexam-exam-header h3 {
    font-size: 18px; font-weight: 800;
    color: var(--text-primary);
}
.mexam-exam-meta {
    display: flex; gap: 16px; align-items: center;
}
.mexam-exam-meta span {
    font-size: 13px; font-weight: 600;
    color: var(--text-secondary);
}
.mexam-timer {
    background: rgba(139,92,246,0.12);
    padding: 4px 10px; border-radius: 8px;
    color: var(--accent) !important;
    font-variant-numeric: tabular-nums;
}
.mexam-progress-bar {
    height: 4px; background: var(--border);
    border-radius: 4px; margin-bottom: 20px;
    overflow: hidden;
}
.mexam-progress-fill {
    height: 100%; background: linear-gradient(90deg, var(--accent), var(--accent-light));
    border-radius: 4px; transition: width 0.3s;
}
.mexam-question-area {
    min-height: 300px;
}
.mexam-q-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 16px; padding: 24px;
    animation: fadeUp 0.3s ease;
}
@keyframes fadeUp {
    from { opacity: 0; transform: translateY(12px); }
    to   { opacity: 1; transform: translateY(0); }
}
.mexam-q-badges {
    display: flex; gap: 8px; flex-wrap: wrap;
    margin-bottom: 14px;
}
.mexam-badge {
    font-size: 10px; font-weight: 700;
    padding: 3px 8px; border-radius: 6px;
    text-transform: uppercase; letter-spacing: 0.5px;
}
.mexam-badge-easy { background: rgba(16,185,129,0.15); color: #34d399; }
.mexam-badge-medium { background: rgba(251,191,36,0.15); color: #fbbf24; }
.mexam-badge-hard { background: rgba(239,68,68,0.15); color: #f87171; }
.mexam-badge-cross {
    background: rgba(96,165,250,0.15); color: #60a5fa;
}
.mexam-badge-source {
    background: rgba(255,255,255,0.06); color: var(--text-secondary);
    font-weight: 500; text-transform: none;
    max-width: 200px; overflow: hidden;
    text-overflow: ellipsis; white-space: nowrap;
}
.mexam-q-text {
    font-size: 16px; font-weight: 600;
    color: var(--text-primary);
    line-height: 1.5; margin-bottom: 18px;
}
.mexam-q-num {
    color: var(--accent); margin-right: 8px;
}
.mexam-options {
    display: flex; flex-direction: column; gap: 8px;
}
.mexam-opt {
    display: flex; align-items: flex-start;
    gap: 10px; padding: 14px 16px;
    border-radius: 12px; border: 1px solid var(--border);
    background: transparent; cursor: pointer;
    transition: all 0.2s; font-size: 14px;
    color: var(--text-primary); text-align: left;
    font-family: var(--font); width: 100%;
}
.mexam-opt:hover {
    border-color: var(--accent);
    background: rgba(139,92,246,0.06);
}
.mexam-opt.selected {
    border-color: var(--accent);
    background: rgba(139,92,246,0.1);
}
.mexam-opt.correct {
    border-color: #10b981;
    background: rgba(16,185,129,0.1);
}
.mexam-opt.wrong {
    border-color: #ef4444;
    background: rgba(239,68,68,0.08);
}
.mexam-opt-letter {
    width: 26px; height: 26px; border-radius: 8px;
    display: flex; align-items: center;
    justify-content: center; flex-shrink: 0;
    font-weight: 700; font-size: 12px;
    background: rgba(255,255,255,0.06);
    color: var(--text-secondary);
}
.mexam-opt.selected .mexam-opt-letter {
    background: var(--accent); color: #fff;
}
.mexam-opt.correct .mexam-opt-letter {
    background: #10b981; color: #fff;
}
.mexam-opt.wrong .mexam-opt-letter {
    background: #ef4444; color: #fff;
}
.mexam-explanation {
    margin-top: 14px; padding: 14px;
    border-radius: 10px;
    background: rgba(139,92,246,0.06);
    border-left: 3px solid var(--accent);
    font-size: 13px; color: var(--text-secondary);
    line-height: 1.5;
    animation: fadeUp 0.3s ease;
}

/* Nav */
.mexam-nav {
    display: flex; justify-content: center;
    gap: 10px; margin-top: 24px; padding-bottom: 20px;
}
.mexam-nav-btn {
    padding: 10px 24px; border-radius: 10px;
    border: 1px solid var(--border);
    background: var(--bg-card);
    color: var(--text-primary);
    font-weight: 600; font-size: 14px;
    cursor: pointer; transition: all 0.2s;
    font-family: var(--font);
}
.mexam-nav-btn:hover:not(:disabled) {
    border-color: var(--accent);
}
.mexam-nav-btn:disabled { opacity: 0.3; cursor: not-allowed; }
.mexam-nav-btn.mexam-primary {
    background: var(--accent); color: #fff;
    border-color: var(--accent);
}
.mexam-nav-btn.mexam-submit {
    background: linear-gradient(135deg, #10b981, #059669);
    color: #fff; border: none;
}

/* ── Step 4: Results ── */
.mexam-results {
    text-align: center; padding: 30px 0;
}
.mexam-score-circle {
    width: 160px; height: 160px;
    border-radius: 50%; margin: 0 auto 24px;
    display: flex; flex-direction: column;
    align-items: center; justify-content: center;
    border: 6px solid var(--accent);
    background: rgba(139,92,246,0.06);
}
.mexam-score-num {
    font-size: 42px; font-weight: 900;
    color: var(--accent);
}
.mexam-score-label {
    font-size: 12px; color: var(--text-secondary);
}
.mexam-result-title {
    font-size: 24px; font-weight: 800;
    color: var(--text-primary); margin-bottom: 8px;
}
.mexam-result-subtitle {
    font-size: 14px; color: var(--text-secondary);
    margin-bottom: 24px;
}
.mexam-result-stats {
    display: flex; justify-content: center;
    gap: 20px; flex-wrap: wrap;
    margin-bottom: 30px;
}
.mexam-stat {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 12px; padding: 14px 20px;
    min-width: 100px;
}
.mexam-stat-num {
    font-size: 22px; font-weight: 800;
    color: var(--text-primary);
}
.mexam-stat-label {
    font-size: 11px; color: var(--text-secondary);
}
.mexam-result-actions {
    display: flex; justify-content: center;
    gap: 12px; flex-wrap: wrap;
}
.mexam-result-btn {
    padding: 10px 24px; border-radius: 10px;
    border: 1px solid var(--border);
    background: var(--bg-card);
    color: var(--text-primary);
    font-weight: 600; font-size: 14px;
    cursor: pointer; transition: all 0.2s;
    font-family: var(--font);
}
.mexam-result-btn:hover { border-color: var(--accent); }
.mexam-result-btn.primary {
    background: var(--accent); color: #fff;
    border-color: var(--accent);
}
.mexam-review-list {
    text-align: left; margin-top: 30px;
    display: flex; flex-direction: column; gap: 12px;
}
.mexam-review-item {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 12px; padding: 16px;
}
.mexam-review-item.correct { border-left: 3px solid #10b981; }
.mexam-review-item.wrong { border-left: 3px solid #ef4444; }
.mexam-review-q {
    font-size: 14px; font-weight: 600;
    color: var(--text-primary); margin-bottom: 6px;
}
.mexam-review-answer {
    font-size: 12px; color: var(--text-secondary);
}

/* ── Tabs ── */
.mexam-tabs {
    display: flex; gap: 4px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 12px; padding: 4px;
    margin-bottom: 16px;
}
.mexam-tab {
    flex: 1; padding: 10px 16px;
    border-radius: 10px; border: none;
    background: transparent;
    color: var(--text-secondary);
    font-weight: 600; font-size: 13px;
    cursor: pointer; transition: all 0.2s;
    display: flex; align-items: center;
    justify-content: center; gap: 6px;
    font-family: var(--font);
}
.mexam-tab:hover { color: var(--text-primary); }
.mexam-tab.active {
    background: var(--accent);
    color: #fff;
}
.mexam-hist-count {
    background: rgba(255,255,255,0.2);
    padding: 1px 7px; border-radius: 10px;
    font-size: 11px;
}
.mexam-tab.active .mexam-hist-count {
    background: rgba(255,255,255,0.25);
}

/* ── Exam History Cards ── */
.mexam-history-list {
    display: flex; flex-direction: column;
    gap: 10px; padding-bottom: 40px;
}
.mexam-hist-empty {
    text-align: center; padding: 60px 20px;
    color: var(--text-secondary); font-size: 14px;
}
.mexam-hist-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 14px; padding: 16px;
    display: flex; align-items: center;
    gap: 14px; cursor: pointer;
    transition: all 0.2s;
    position: relative;
}
.mexam-hist-card:hover {
    border-color: var(--accent);
    transform: translateY(-1px);
    box-shadow: 0 4px 20px rgba(0,0,0,0.15);
}
.mexam-hist-score {
    width: 56px; height: 56px;
    border-radius: 50%; flex-shrink: 0;
    display: flex; flex-direction: column;
    align-items: center; justify-content: center;
    font-weight: 900; font-size: 18px;
    border: 3px solid;
}
.mexam-hist-score.grade-a { border-color: #10b981; color: #10b981; background: rgba(16,185,129,0.08); }
.mexam-hist-score.grade-b { border-color: #60a5fa; color: #60a5fa; background: rgba(96,165,250,0.08); }
.mexam-hist-score.grade-c { border-color: #fbbf24; color: #fbbf24; background: rgba(251,191,36,0.08); }
.mexam-hist-score.grade-f { border-color: #f87171; color: #f87171; background: rgba(248,113,113,0.08); }
.mexam-hist-score.grade-draft { border-color: #fbbf24; color: #fbbf24; background: rgba(251,191,36,0.06); border-style: dashed; }
.mexam-hist-grade {
    font-size: 9px; font-weight: 700; opacity: 0.7;
}
.mexam-hist-info { flex: 1; min-width: 0; }
.mexam-hist-name {
    font-size: 14px; font-weight: 700;
    color: var(--text-primary);
    white-space: nowrap; overflow: hidden;
    text-overflow: ellipsis;
}
.mexam-hist-detail {
    font-size: 11px; color: var(--text-secondary);
    margin-top: 3px;
}
.mexam-hist-diff-bar {
    display: flex; gap: 6px; margin-top: 5px;
}
.mexam-hist-diff-chip {
    font-size: 9px; font-weight: 700;
    padding: 1px 6px; border-radius: 4px;
}
.mexam-hist-actions {
    display: flex; gap: 6px; flex-shrink: 0;
}
.mexam-hist-action-btn {
    width: 32px; height: 32px; border-radius: 8px;
    border: 1px solid var(--border);
    background: transparent;
    color: var(--text-secondary);
    cursor: pointer; display: flex;
    align-items: center; justify-content: center;
    transition: all 0.2s;
}
.mexam-hist-action-btn:hover {
    border-color: var(--accent);
    color: var(--accent);
}
.mexam-hist-action-btn.delete:hover {
    border-color: #ef4444; color: #ef4444;
}

@media (max-width: 640px) {
    .mexam-inner { padding: 0 12px; }
    .mexam-header {
        flex-direction: row;
        align-items: center;
        gap: 0;
    }
    .mexam-header > div:last-child { width: 36px !important; }
    .mexam-header > div:nth-child(2) { flex: 1; text-align: center; }
    .mexam-title { font-size: 17px; }
    .mexam-subtitle { font-size: 11px; }
    .mexam-q-card { padding: 16px; }
    .mexam-q-text { font-size: 14px; }
    .mexam-opt { padding: 12px; font-size: 13px; }
    .mexam-options-row { flex-direction: column; gap: 12px; }
    .mexam-generate-btn { width: 100%; justify-content: center; }
    .mexam-video-thumb { width: 48px; height: 27px; }
    .mexam-tab { font-size: 12px; padding: 8px 10px; }
    .mexam-hist-card { padding: 12px; gap: 10px; }
    .mexam-hist-score { width: 44px; height: 44px; font-size: 15px; }
}



@media (max-width: 480px) {
    .mexam-page { }
}