/* ============================================
   CHINESE MASTER - Enhanced Activity UI
   Cleaner, more intuitive activity templates
   ============================================ */

/* ===== Shared activity scaffolding ===== */
.activity-card {
    background: var(--bg-card);
    border: 1px solid var(--glass-border);
    border-radius: 18px;
    padding: 28px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.18);
    max-width: 820px;
    margin: 0 auto;
    animation: fadeInUp 0.35s ease both;
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.activity-card + .activity-card {
    margin-top: 20px;
}

.activity-prompt {
    text-align: center;
}

.activity-eyebrow {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 4px 12px;
    background: rgba(255, 107, 107, 0.15);
    color: #fca5a5;
    border-radius: 999px;
    font-size: 12px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin-bottom: 12px;
}

.activity-title {
    font-size: 22px;
    font-weight: 700;
    color: var(--text-primary);
    margin: 0 0 6px;
}

.activity-subtitle {
    color: var(--text-secondary);
    font-size: 14px;
    margin: 0;
}

.activity-progress-dots {
    display: flex;
    justify-content: center;
    gap: 6px;
    margin-top: 16px;
}

.activity-progress-dots .dot {
    width: 8px;
    height: 8px;
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.15);
    transition: all 0.25s ease;
}

.activity-progress-dots .dot.done {
    background: var(--color-success, #10b981);
}

.activity-progress-dots .dot.current {
    background: var(--color-primary-light, #fca5a5);
    transform: scale(1.4);
    box-shadow: 0 0 0 4px rgba(255, 107, 107, 0.2);
}

/* ===== Audio control ===== */
.audio-hero {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 14px;
    padding: 28px;
    background: linear-gradient(135deg, rgba(255, 107, 107, 0.12), rgba(155, 89, 182, 0.08));
    border: 1px solid rgba(255, 255, 255, 0.06);
    border-radius: 18px;
    margin-bottom: 24px;
}

.audio-hero .audio-btn {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--color-primary-light, #fca5a5), var(--color-primary-dark, #ef4444));
    border: none;
    color: white;
    font-size: 32px;
    cursor: pointer;
    box-shadow: 0 8px 24px rgba(255, 107, 107, 0.4);
    transition: transform 0.2s, box-shadow 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
}

.audio-hero .audio-btn:hover {
    transform: scale(1.05);
    box-shadow: 0 10px 30px rgba(255, 107, 107, 0.55);
}

.audio-hero .audio-btn:active {
    transform: scale(0.96);
}

.audio-hero .audio-btn.playing {
    animation: audioPulse 1.4s ease-in-out infinite;
}

.audio-hero .audio-hint {
    color: rgba(255, 255, 255, 0.7);
    font-size: 13px;
    font-weight: 500;
}

@keyframes audioPulse {
    0%, 100% { box-shadow: 0 8px 24px rgba(255, 107, 107, 0.4); }
    50% { box-shadow: 0 8px 36px rgba(255, 107, 107, 0.7); }
}

/* ===== Hint chip ===== */
.hint-chip {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 14px;
    background: rgba(167, 139, 250, 0.12);
    color: #c4b5fa;
    border: 1px solid rgba(167, 139, 250, 0.25);
    border-radius: 999px;
    font-size: 13px;
    margin: 12px 0;
}

.hint-chip .hint-icon {
    font-size: 14px;
}

/* ===== Dictation ===== */
.dictation-stage {
    max-width: 640px;
    margin: 0 auto;
}

.dictation-input-wrap {
    position: relative;
}

.dictation-input {
    width: 100%;
    padding: 18px 20px;
    font-size: 22px;
    font-family: 'Noto Sans SC', sans-serif;
    text-align: center;
    background: rgba(255, 255, 255, 0.05);
    border: 2px solid rgba(255, 255, 255, 0.12);
    border-radius: 14px;
    color: white;
    transition: all 0.2s;
    letter-spacing: 0.05em;
}

.dictation-input::placeholder {
    color: rgba(255, 255, 255, 0.35);
    font-size: 16px;
}

.dictation-input:focus {
    outline: none;
    border-color: var(--color-primary-light, #fca5a5);
    background: rgba(255, 255, 255, 0.08);
    box-shadow: 0 0 0 4px rgba(255, 107, 107, 0.15);
}

.dictation-input.correct {
    border-color: var(--color-success, #10b981);
    background: rgba(6, 182, 212, 0.08);
    color: var(--color-success, #10b981);
}

.dictation-input.close {
    border-color: var(--color-warning, #f59e0b);
    background: rgba(212, 149, 43, 0.08);
    color: var(--color-warning, #f59e0b);
}

.dictation-input.incorrect {
    border-color: var(--color-danger, #ff6b6b);
    background: rgba(255, 107, 107, 0.08);
}

.dictation-counter {
    position: absolute;
    right: 14px;
    top: 50%;
    transform: translateY(-50%);
    font-size: 11px;
    color: rgba(255, 255, 255, 0.4);
}

.dictation-actions {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-top: 18px;
    flex-wrap: wrap;
}

.icon-btn {
    padding: 8px 14px;
    border-radius: 10px;
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.8);
    font-size: 13px;
    cursor: pointer;
    transition: all 0.2s;
}

.icon-btn:hover {
    background: rgba(255, 255, 255, 0.12);
    color: white;
}

.dictation-answer-reveal {
    margin-top: 18px;
    padding: 16px 20px;
    background: rgba(255, 255, 255, 0.04);
    border-radius: 12px;
    border-left: 3px solid var(--color-success, #10b981);
    text-align: center;
    animation: fadeInUp 0.3s ease;
}

.dictation-answer-reveal .answer-cn {
    font-family: 'Noto Sans SC', sans-serif;
    font-size: 28px;
    color: white;
    margin-bottom: 6px;
    letter-spacing: 0.05em;
}

.dictation-answer-reveal .answer-py {
    color: rgba(255, 255, 255, 0.6);
    font-size: 14px;
    font-style: italic;
}

/* ===== Answer feedback ===== */
.answer-feedback {
    margin-top: 14px;
    padding: 10px 16px;
    border-radius: 10px;
    font-size: 14px;
    font-weight: 600;
    text-align: center;
    animation: fadeInUp 0.25s ease;
}

.answer-feedback.correct {
    background: rgba(6, 182, 212, 0.12);
    color: #67e8f9;
    border: 1px solid rgba(6, 182, 212, 0.3);
}

.answer-feedback.close {
    background: rgba(212, 149, 43, 0.12);
    color: #c4b5fa;
    border: 1px solid rgba(212, 149, 43, 0.3);
}

.answer-feedback.incorrect {
    background: rgba(255, 107, 107, 0.12);
    color: #fca5a5;
    border: 1px solid rgba(255, 107, 107, 0.3);
}

/* ===== Comprehension: passage + questions ===== */
.passage-hero {
    padding: 24px 28px;
    background: linear-gradient(135deg, rgba(96, 149, 192, 0.12), rgba(155, 89, 182, 0.06));
    border: 1px solid rgba(255, 255, 255, 0.06);
    border-radius: 18px;
    margin-bottom: 24px;
}

.passage-hero .passage-label {
    font-size: 12px;
    color: rgba(255, 255, 255, 0.5);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin-bottom: 10px;
    font-weight: 600;
}

.passage-hero .passage-text {
    font-family: 'Noto Sans SC', sans-serif;
    font-size: 22px;
    line-height: 1.7;
    color: white;
    margin: 0;
}

.passage-hero .passage-pinyin {
    color: rgba(255, 255, 255, 0.55);
    font-size: 14px;
    margin-top: 10px;
    font-style: italic;
}

.comprehension-question {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 14px;
    padding: 20px;
    margin-bottom: 16px;
}

.comprehension-question .q-number {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 28px;
    height: 28px;
    border-radius: 999px;
    background: var(--color-primary-light, #fca5a5);
    color: white;
    font-size: 13px;
    font-weight: 700;
    margin-right: 10px;
}

.comprehension-question .q-text {
    display: inline;
    font-family: 'Noto Sans SC', sans-serif;
    font-size: 17px;
    font-weight: 500;
    color: white;
    vertical-align: middle;
}

.comprehension-options {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 10px;
    margin-top: 14px;
}

.listening-option {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 14px 16px;
    background: rgba(255, 255, 255, 0.04);
    border: 2px solid rgba(255, 255, 255, 0.08);
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.2s;
    font-family: 'Noto Sans SC', sans-serif;
    font-size: 15px;
}

.listening-option:hover {
    background: rgba(255, 255, 255, 0.08);
    border-color: rgba(255, 255, 255, 0.2);
    transform: translateY(-1px);
}

.listening-option.selected {
    border-color: var(--color-primary-light, #fca5a5);
    background: rgba(255, 107, 107, 0.1);
}

.listening-option.correct {
    border-color: var(--color-success, #10b981);
    background: rgba(6, 182, 212, 0.15);
    color: #67e8f9;
}

.listening-option.incorrect {
    border-color: var(--color-danger, #ff6b6b);
    background: rgba(255, 107, 107, 0.15);
    color: #fca5a5;
}

.listening-option .option-letter {
    flex-shrink: 0;
    width: 28px;
    height: 28px;
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.08);
    color: rgba(255, 255, 255, 0.7);
    font-family: 'Inter', sans-serif;
    font-size: 13px;
    font-weight: 700;
    display: flex;
    align-items: center;
    justify-content: center;
}

.listening-option.correct .option-letter {
    background: var(--color-success, #10b981);
    color: white;
}

.listening-option.incorrect .option-letter {
    background: var(--color-danger, #ff6b6b);
    color: white;
}

/* ===== Minimal pairs ===== */
.minimal-pairs-stage {
    max-width: 720px;
    margin: 0 auto;
}

.minimal-pair-cards {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 18px;
}

.minimal-pair-card {
    background: rgba(255, 255, 255, 0.04);
    border: 2px solid rgba(255, 255, 255, 0.08);
    border-radius: 18px;
    padding: 28px 18px;
    text-align: center;
    cursor: pointer;
    transition: all 0.2s;
    position: relative;
    overflow: hidden;
}

.minimal-pair-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--color-primary-light, #fca5a5), var(--color-primary-dark, #ef4444));
    opacity: 0;
    transition: opacity 0.2s;
}

.minimal-pair-card:hover {
    border-color: rgba(255, 255, 255, 0.2);
    background: rgba(255, 255, 255, 0.08);
    transform: translateY(-2px);
}

.minimal-pair-card:hover::before {
    opacity: 1;
}

.minimal-pair-card.selected {
    border-color: var(--color-primary-light, #fca5a5);
    background: rgba(255, 107, 107, 0.08);
}

.minimal-pair-card.correct {
    border-color: var(--color-success, #10b981);
    background: rgba(6, 182, 212, 0.12);
}

.minimal-pair-card.correct::before {
    opacity: 1;
    background: var(--color-success, #10b981);
}

.minimal-pair-card.incorrect {
    border-color: var(--color-danger, #ff6b6b);
    background: rgba(255, 107, 107, 0.12);
}

.minimal-pair-card.incorrect::before {
    opacity: 1;
    background: var(--color-danger, #ff6b6b);
}

.minimal-pair-card .pair-char {
    font-family: 'Noto Sans SC', sans-serif;
    font-size: 64px;
    color: white;
    margin-bottom: 6px;
    line-height: 1;
}

.minimal-pair-card .pair-py {
    font-size: 18px;
    color: rgba(255, 255, 255, 0.7);
    margin-bottom: 4px;
    font-style: italic;
}

.minimal-pair-card .pair-meaning {
    font-size: 13px;
    color: rgba(255, 255, 255, 0.55);
}

.minimal-pairs-controls {
    display: flex;
    justify-content: center;
    gap: 10px;
    flex-wrap: wrap;
}

.minimal-pairs-controls .btn {
    padding: 10px 18px;
    border-radius: 12px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    border: 1px solid rgba(255, 255, 255, 0.1);
    background: rgba(255, 255, 255, 0.04);
    color: rgba(255, 255, 255, 0.85);
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

.minimal-pairs-controls .btn:hover {
    background: rgba(255, 255, 255, 0.1);
    transform: translateY(-1px);
}

.minimal-pairs-controls .btn-primary {
    background: linear-gradient(135deg, var(--color-primary-light, #fca5a5), var(--color-primary-dark, #ef4444));
    border: none;
    color: white;
    font-weight: 600;
}

/* ===== Dialogue ===== */
.dialogue-list {
    max-width: 600px;
    margin: 0 auto;
}

.dialogue-turn {
    display: flex;
    gap: 12px;
    margin-bottom: 16px;
    animation: fadeInUp 0.3s ease both;
}

.dialogue-turn.speaker-a {
    flex-direction: row;
}

.dialogue-turn.speaker-b {
    flex-direction: row-reverse;
}

.dialogue-turn.speaker-b .dialogue-bubble {
    background: linear-gradient(135deg, rgba(255, 107, 107, 0.18), rgba(255, 107, 107, 0.05));
    border-color: rgba(255, 107, 107, 0.25);
}

.dialogue-turn.speaker-b .dialogue-avatar {
    background: linear-gradient(135deg, var(--color-primary-light, #fca5a5), var(--color-primary-dark, #ef4444));
}

.dialogue-avatar {
    flex-shrink: 0;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--color-info, #3b82f6), var(--color-info-dark, #2563eb));
    color: white;
    font-weight: 700;
    font-size: 18px;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.25);
}

.dialogue-bubble {
    flex: 1;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 16px;
    padding: 14px 18px;
    position: relative;
}

.dialogue-text {
    font-family: 'Noto Sans SC', sans-serif;
    font-size: 19px;
    color: white;
    line-height: 1.5;
    margin-bottom: 6px;
}

.dialogue-pinyin {
    font-size: 13px;
    color: rgba(255, 255, 255, 0.55);
    font-style: italic;
    margin-bottom: 8px;
}

.dialogue-meaning {
    font-size: 13px;
    color: rgba(255, 255, 255, 0.75);
    padding-top: 8px;
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    transition: all 0.3s;
}

.dialogue-meaning.dialogue-hidden {
    color: transparent;
    user-select: none;
    background: repeating-linear-gradient(
        45deg,
        rgba(255, 255, 255, 0.04),
        rgba(255, 255, 255, 0.04) 6px,
        rgba(255, 255, 255, 0.08) 6px,
        rgba(255, 255, 255, 0.08) 12px
    );
    border-radius: 6px;
    padding: 8px;
    text-align: center;
}

.dialogue-meaning.dialogue-hidden::before {
    content: '?';
    color: rgba(255, 255, 255, 0.4);
    font-weight: 700;
}

.dialogue-meaning.revealed {
    color: rgba(255, 255, 255, 0.85);
    background: rgba(6, 182, 212, 0.06);
    border-radius: 6px;
    padding: 8px 10px;
}

.dialogue-actions {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-top: 18px;
    flex-wrap: wrap;
}

/* ===== Speed listening ===== */
.speed-stage {
    max-width: 600px;
    margin: 0 auto;
}

.speed-readout {
    text-align: center;
    margin: 18px 0;
    padding: 18px;
    background: rgba(255, 255, 255, 0.03);
    border-radius: 14px;
}

.speed-readout .speed-display {
    font-size: 42px;
    font-weight: 700;
    color: var(--color-primary-light, #fca5a5);
    line-height: 1;
}

.speed-readout .speed-label {
    font-size: 12px;
    color: rgba(255, 255, 255, 0.55);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-top: 4px;
}

.speed-marks {
    display: flex;
    justify-content: space-between;
    font-size: 11px;
    color: rgba(255, 255, 255, 0.4);
    margin-top: 6px;
    padding: 0 4px;
}

.speed-slider {
    width: 100%;
    margin: 8px 0 4px;
}

.speed-presets {
    display: flex;
    justify-content: center;
    gap: 8px;
    margin-top: 12px;
    flex-wrap: wrap;
}

.speed-preset {
    padding: 6px 14px;
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.08);
    color: rgba(255, 255, 255, 0.7);
    font-size: 13px;
    cursor: pointer;
    transition: all 0.2s;
}

.speed-preset:hover {
    background: rgba(255, 255, 255, 0.1);
    color: white;
}

.speed-preset.active {
    background: var(--color-primary-light, #fca5a5);
    border-color: var(--color-primary-light, #fca5a5);
    color: white;
}

/* ===== Shadowing ===== */
.shadowing-stage {
    max-width: 580px;
    margin: 0 auto;
    text-align: center;
}

.shadowing-display {
    padding: 36px 24px;
    background: linear-gradient(135deg, rgba(155, 89, 182, 0.15), rgba(96, 149, 192, 0.08));
    border: 1px solid rgba(255, 255, 255, 0.06);
    border-radius: 22px;
    margin-bottom: 24px;
}

.shadowing-display .sh-cn {
    font-family: 'Noto Sans SC', sans-serif;
    font-size: 48px;
    color: white;
    margin-bottom: 10px;
    line-height: 1.3;
}

.shadowing-display .sh-py {
    font-size: 18px;
    color: rgba(255, 255, 255, 0.65);
    font-style: italic;
    margin-bottom: 12px;
}

.shadowing-display .sh-meaning {
    font-size: 16px;
    color: rgba(255, 255, 255, 0.8);
}

.shadowing-wave {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    height: 80px;
    margin: 24px 0;
    padding: 0 16px;
}

.shadowing-wave .wave-bar {
    width: 6px;
    background: linear-gradient(180deg, var(--color-primary-light, #fca5a5), var(--color-primary-dark, #ef4444));
    border-radius: 999px;
    animation: wave 1.1s ease-in-out infinite;
    box-shadow: 0 0 8px rgba(255, 107, 107, 0.4);
}

.shadowing-wave.paused .wave-bar {
    animation-play-state: paused;
    opacity: 0.4;
    background: rgba(255, 255, 255, 0.2);
}

.shadowing-actions {
    display: flex;
    justify-content: center;
    gap: 12px;
    flex-wrap: wrap;
}

/* ===== Reading: character match ===== */
.character-match-stage {
    max-width: 760px;
    margin: 0 auto;
}

.match-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 18px;
    margin-top: 20px;
}

.match-column h4 {
    text-align: center;
    color: rgba(255, 255, 255, 0.6);
    font-size: 13px;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin: 0 0 10px;
}

.match-item {
    background: rgba(255, 255, 255, 0.04);
    border: 2px solid rgba(255, 255, 255, 0.08);
    border-radius: 12px;
    padding: 16px;
    margin-bottom: 8px;
    text-align: center;
    cursor: pointer;
    transition: all 0.2s;
}

.match-item.character-item {
    font-family: 'Noto Sans SC', sans-serif;
    font-size: 28px;
    color: white;
}

.match-item:hover {
    border-color: rgba(255, 255, 255, 0.2);
    background: rgba(255, 255, 255, 0.08);
    transform: translateY(-1px);
}

.match-item.selected {
    border-color: var(--color-primary-light, #fca5a5);
    background: rgba(255, 107, 107, 0.12);
}

.match-item.matched {
    border-color: var(--color-success, #10b981);
    background: rgba(6, 182, 212, 0.12);
    color: #67e8f9;
    cursor: default;
    opacity: 0.7;
}

.match-item.incorrect {
    border-color: var(--color-danger, #ff6b6b);
    background: rgba(255, 107, 107, 0.12);
}

.match-progress {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    padding: 12px 16px;
    background: rgba(255, 255, 255, 0.04);
    border-radius: 999px;
    margin: 16px auto;
    max-width: 240px;
}

.match-progress .match-count {
    font-weight: 700;
    color: white;
}

.match-progress .match-progress-bar {
    flex: 1;
    height: 6px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 999px;
    overflow: hidden;
}

.match-progress .match-progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--color-success, #10b981), var(--color-success-dark, #059669));
    border-radius: 999px;
    transition: width 0.3s ease;
}

/* ===== Sentence completion ===== */
.sentence-stage {
    max-width: 640px;
    margin: 0 auto;
}

.sentence-display {
    padding: 28px;
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.05), rgba(255, 255, 255, 0.02));
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 18px;
    text-align: center;
    margin-bottom: 20px;
}

.sentence-display .sentence-cn {
    font-family: 'Noto Sans SC', sans-serif;
    font-size: 28px;
    color: white;
    line-height: 1.5;
    margin-bottom: 12px;
    letter-spacing: 0.03em;
}

.sentence-display .sentence-cn .blank-slot {
    display: inline-block;
    min-width: 70px;
    border-bottom: 3px solid var(--color-primary-light, #fca5a5);
    color: var(--color-primary-light, #fca5a5);
    font-weight: 700;
    text-align: center;
    padding: 0 6px;
}

.sentence-display .sentence-meaning {
    color: rgba(255, 255, 255, 0.65);
    font-size: 15px;
    font-style: italic;
}

.sentence-options {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 10px;
}

.sentence-option {
    padding: 16px;
    background: rgba(255, 255, 255, 0.04);
    border: 2px solid rgba(255, 255, 255, 0.08);
    border-radius: 12px;
    text-align: center;
    cursor: pointer;
    transition: all 0.2s;
    font-family: 'Noto Sans SC', sans-serif;
    font-size: 20px;
    color: white;
}

.sentence-option:hover {
    background: rgba(255, 255, 255, 0.08);
    border-color: rgba(255, 255, 255, 0.2);
    transform: translateY(-1px);
}

.sentence-option.selected {
    border-color: var(--color-primary-light, #fca5a5);
    background: rgba(255, 107, 107, 0.12);
}

.sentence-option.correct {
    border-color: var(--color-success, #10b981);
    background: rgba(6, 182, 212, 0.15);
    color: #67e8f9;
}

.sentence-option.incorrect {
    border-color: var(--color-danger, #ff6b6b);
    background: rgba(255, 107, 107, 0.15);
    color: #fca5a5;
}

/* ===== Passage reading ===== */
.passage-stage {
    max-width: 720px;
    margin: 0 auto;
}

.passage-card {
    padding: 28px;
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.05), rgba(255, 255, 255, 0.02));
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 18px;
    margin-bottom: 20px;
}

.passage-card .passage-title {
    font-size: 18px;
    color: var(--color-primary-light, #fca5a5);
    margin: 0 0 16px;
    font-weight: 700;
}

.passage-card .passage-title small {
    color: rgba(255, 255, 255, 0.5);
    font-weight: 400;
    margin-left: 8px;
}

.passage-card .passage-body {
    font-family: 'Noto Sans SC', sans-serif;
    font-size: 21px;
    line-height: 1.85;
    color: white;
    margin: 0;
    letter-spacing: 0.02em;
}

.passage-card .passage-pinyin {
    margin-top: 14px;
    padding: 14px;
    background: rgba(255, 255, 255, 0.03);
    border-radius: 10px;
    color: rgba(255, 255, 255, 0.6);
    font-size: 13px;
    line-height: 1.7;
    font-style: italic;
}

.passage-questions {
    margin-top: 20px;
}

.passage-question {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 14px;
    padding: 18px;
    margin-bottom: 12px;
}

.passage-question .q-header {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    margin-bottom: 12px;
}

.passage-options {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
}

.passage-option {
    padding: 10px 14px;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.2s;
    font-size: 14px;
    color: white;
}

.passage-option:hover {
    background: rgba(255, 255, 255, 0.08);
}

.passage-option.selected {
    border-color: var(--color-primary-light, #fca5a5);
    background: rgba(255, 107, 107, 0.12);
}

.passage-option.correct {
    border-color: var(--color-success, #10b981);
    background: rgba(6, 182, 212, 0.15);
    color: #67e8f9;
}

.passage-option.incorrect {
    border-color: var(--color-danger, #ff6b6b);
    background: rgba(255, 107, 107, 0.15);
    color: #fca5a5;
}

/* ===== Speed reading ===== */
.speed-reading-stage {
    max-width: 720px;
    margin: 0 auto;
}

.speed-timer {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 14px;
    margin: 16px 0 20px;
    padding: 16px 20px;
    background: linear-gradient(135deg, rgba(255, 107, 107, 0.15), rgba(155, 89, 182, 0.08));
    border: 1px solid rgba(255, 107, 107, 0.25);
    border-radius: 14px;
}

.speed-timer .timer-value {
    font-size: 36px;
    font-weight: 800;
    color: #ff6b6b;
    line-height: 1;
    font-variant-numeric: tabular-nums;
}

.speed-timer .timer-value.warning {
    color: var(--color-warning, #f59e0b);
    animation: pulse 0.5s ease infinite;
}

.speed-timer .timer-value.danger {
    color: var(--color-danger, #ff6b6b);
    animation: pulse 0.3s ease infinite;
}

@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.08); }
}

.speed-timer .timer-label {
    color: rgba(255, 255, 255, 0.65);
    font-size: 13px;
    text-transform: uppercase;
    letter-spacing: 0.08em;
}

/* ===== Radical learning ===== */
.radical-stage {
    max-width: 700px;
    margin: 0 auto;
}

.radical-hero {
    text-align: center;
    padding: 32px 20px;
    background: linear-gradient(135deg, rgba(255, 107, 107, 0.12), rgba(155, 89, 182, 0.06));
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 22px;
    margin-bottom: 24px;
}

.radical-hero .radical-glyph {
    font-family: 'Noto Sans SC', sans-serif;
    font-size: 96px;
    color: white;
    line-height: 1;
    margin-bottom: 8px;
    text-shadow: 0 4px 20px rgba(255, 107, 107, 0.3);
}

.radical-hero .radical-name {
    color: #fca5a5;
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 4px;
}

.radical-hero .radical-meaning {
    color: rgba(255, 255, 255, 0.7);
    font-size: 14px;
}

.radical-characters {
    margin-top: 16px;
}

.radical-characters h4 {
    color: rgba(255, 255, 255, 0.6);
    font-size: 13px;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin: 0 0 12px;
    text-align: center;
}

.radical-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(110px, 1fr));
    gap: 12px;
}

.radical-card {
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 14px;
    padding: 18px 12px;
    text-align: center;
    transition: all 0.2s;
    cursor: pointer;
}

.radical-card:hover {
    background: rgba(255, 255, 255, 0.08);
    transform: translateY(-2px);
    border-color: rgba(255, 255, 255, 0.15);
}

.radical-card .radical-char {
    font-family: 'Noto Sans SC', sans-serif;
    font-size: 38px;
    color: white;
    margin-bottom: 6px;
}

.radical-card .radical-char-meaning {
    color: rgba(255, 255, 255, 0.7);
    font-size: 12px;
}

/* ===== Context clues ===== */
.context-stage {
    max-width: 680px;
    margin: 0 auto;
}

.context-sentence {
    padding: 24px 28px;
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.05), rgba(255, 255, 255, 0.02));
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 16px;
    text-align: center;
    font-family: 'Noto Sans SC', sans-serif;
    font-size: 22px;
    line-height: 1.7;
    color: white;
    margin-bottom: 18px;
}

.context-sentence .unknown-word {
    display: inline-block;
    padding: 2px 8px;
    background: rgba(255, 107, 107, 0.18);
    border-bottom: 2px solid var(--color-primary-light, #fca5a5);
    color: #fca5a5;
    font-weight: 700;
    margin: 0 2px;
    border-radius: 4px;
}

.context-hints {
    margin: 18px 0;
    padding: 14px 18px;
    background: rgba(167, 139, 250, 0.06);
    border: 1px solid rgba(167, 139, 250, 0.18);
    border-radius: 12px;
}

.context-hints .hints-label {
    color: #c4b5fa;
    font-size: 12px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin-bottom: 6px;
}

.context-hints ul {
    margin: 0;
    padding: 0;
    list-style: none;
}

.context-hints li {
    color: rgba(255, 255, 255, 0.8);
    font-size: 14px;
    padding: 4px 0 4px 18px;
    position: relative;
}

.context-hints li::before {
    content: '💡';
    position: absolute;
    left: 0;
    top: 4px;
    font-size: 11px;
}

.context-options {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 10px;
}

.context-option {
    padding: 14px;
    background: rgba(255, 255, 255, 0.04);
    border: 2px solid rgba(255, 255, 255, 0.08);
    border-radius: 12px;
    text-align: center;
    cursor: pointer;
    transition: all 0.2s;
    color: white;
    font-size: 15px;
}

.context-option:hover {
    background: rgba(255, 255, 255, 0.08);
    border-color: rgba(255, 255, 255, 0.2);
    transform: translateY(-1px);
}

.context-option.selected {
    border-color: var(--color-primary-light, #fca5a5);
    background: rgba(255, 107, 107, 0.12);
}

.context-option.correct {
    border-color: var(--color-success, #10b981);
    background: rgba(6, 182, 212, 0.15);
    color: #67e8f9;
}

.context-option.incorrect {
    border-color: var(--color-danger, #ff6b6b);
    background: rgba(255, 107, 107, 0.15);
    color: #fca5a5;
}

.context-feedback {
    margin-top: 14px;
    padding: 14px 16px;
    background: rgba(6, 182, 212, 0.08);
    border: 1px solid rgba(6, 182, 212, 0.25);
    border-radius: 12px;
    color: rgba(255, 255, 255, 0.85);
    font-size: 14px;
    line-height: 1.55;
}

/* ===== Grammar ===== */

/* --- Search --- */
.grammar-search-wrap {
    margin-bottom: 18px;
    position: relative;
}

.grammar-search {
    width: 100%;
    padding: 14px 18px 14px 44px;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 14px;
    color: white;
    font-size: 15px;
    transition: border-color 0.25s, background 0.25s, box-shadow 0.25s;
    box-sizing: border-box;
    backdrop-filter: blur(8px);
}

.grammar-search-wrap::before {
    content: '\1F50D';
    position: absolute;
    left: 16px;
    top: 50%;
    transform: translateY(-50%);
    font-size: 15px;
    opacity: 0.45;
    pointer-events: none;
    z-index: 1;
}

.grammar-search::placeholder {
    color: rgba(255, 255, 255, 0.3);
}

.grammar-search:focus {
    outline: none;
    border-color: rgba(255, 107, 107, 0.5);
    background: rgba(255, 255, 255, 0.07);
    box-shadow: 0 0 0 3px rgba(255, 107, 107, 0.15), 0 4px 16px rgba(0, 0, 0, 0.15);
}

.grammar-no-results {
    text-align: center;
    padding: 48px 20px;
    color: rgba(255, 255, 255, 0.35);
    font-size: 14px;
    font-style: italic;
}

/* --- Progress bar --- */
.grammar-progress-wrap {
    margin-bottom: 14px;
    display: flex;
    align-items: center;
    gap: 12px;
}

.grammar-progress-bar {
    flex: 1;
    height: 6px;
    background: rgba(255,255,255,0.06);
    border-radius: 3px;
    overflow: hidden;
}

.grammar-progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--color-primary, #ff6b6b), var(--color-secondary, #a78bfa));
    border-radius: 3px;
    transition: width 0.5s ease;
}

.grammar-progress-label {
    font-size: 12px;
    color: rgba(255,255,255,0.45);
    white-space: nowrap;
    flex-shrink: 0;
}

/* --- HSK level chips --- */
.grammar-chips {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 12px;
}

.grammar-chip {
    padding: 6px 16px;
    border-radius: 20px;
    border: 1px solid rgba(255,255,255,0.1);
    background: rgba(255,255,255,0.04);
    color: rgba(255,255,255,0.55);
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    font-family: inherit;
}

.grammar-chip:hover {
    border-color: rgba(255,255,255,0.2);
    color: rgba(255,255,255,0.8);
}

.grammar-chip.active {
    border-color: var(--color-primary, #ff6b6b);
    background: rgba(255,107,107,0.15);
    color: var(--color-primary, #ff6b6b);
    box-shadow: 0 0 12px rgba(255,107,107,0.15);
}

/* --- Toggle bar --- */
.grammar-toggle-bar {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 14px;
}

.grammar-toggle-btn {
    padding: 5px 14px;
    border-radius: 16px;
    border: 1px solid rgba(255,255,255,0.08);
    background: rgba(255,255,255,0.03);
    color: rgba(255,255,255,0.5);
    font-size: 12px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    font-family: inherit;
}

.grammar-toggle-btn:hover {
    border-color: rgba(255,255,255,0.17);
    color: rgba(255,255,255,0.75);
}

.grammar-toggle-btn.active {
    border-color: var(--color-accent, #06b6d4);
    background: rgba(6,182,212,0.12);
    color: var(--color-accent, #06b6d4);
}

.grammar-sort-select {
    background: rgba(255,255,255,0.05);
    color: var(--text-primary, #e2e8f0);
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: 8px;
    padding: 6px 10px;
    font-size: 0.85rem;
    font-family: inherit;
    cursor: pointer;
    transition: border-color 0.2s;
}

.grammar-sort-select:focus {
    outline: none;
    border-color: var(--color-accent, #06b6d4);
    box-shadow: 0 0 0 3px rgba(6, 182, 212, 0.15);
}

.grammar-sort-select option {
    background: #1e293b;
    color: #e2e8f0;
}

/* --- Group sections --- */
.grammar-group {
    margin-bottom: 4px;
}

.grammar-group-header {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 16px;
    border-radius: 10px;
    background: rgba(255,255,255,0.03);
    cursor: pointer;
    transition: background 0.2s;
    user-select: none;
}

.grammar-group-header:hover {
    background: rgba(255,255,255,0.06);
}

.grammar-group-arrow {
    font-size: 11px;
    color: rgba(255,255,255,0.3);
    width: 16px;
    text-align: center;
    flex-shrink: 0;
    transition: transform 0.2s;
}

.grammar-group-title {
    flex: 1;
    font-size: 13px;
    font-weight: 700;
    color: rgba(255,255,255,0.65);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.grammar-group-count {
    font-size: 12px;
    font-weight: 600;
    color: rgba(255,255,255,0.35);
    background: rgba(255,255,255,0.05);
    padding: 2px 10px;
    border-radius: 10px;
    flex-shrink: 0;
}

.grammar-group-body {
    padding: 6px 0 6px 8px;
    display: flex;
    flex-direction: column;
    gap: 6px;
}

/* --- Star/bookmark button --- */
.grammar-star-btn {
    flex-shrink: 0;
    background: none;
    border: none;
    color: rgba(255,255,255,0.15);
    font-size: 18px;
    cursor: pointer;
    padding: 4px 8px;
    transition: color 0.2s, transform 0.2s;
    line-height: 1;
    font-family: inherit;
}

.grammar-star-btn:hover {
    color: var(--color-warning, #f59e0b);
    transform: scale(1.2);
}

.grammar-star-btn.starred {
    color: var(--color-warning, #f59e0b);
    text-shadow: 0 0 8px rgba(245,158,11,0.4);
}

/* --- Lesson list --- */
.grammar-lessons-list {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.grammar-lesson-item {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.06);
    border-radius: 14px;
    padding: 16px 20px;
    display: flex;
    gap: 16px;
    align-items: center;
    cursor: pointer;
    transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.grammar-lesson-item::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 3px;
    background: linear-gradient(180deg, var(--color-primary-light, #fca5a5), var(--color-primary-dark, #ef4444));
    opacity: 0;
    transition: opacity 0.25s;
}

.grammar-lesson-item:hover {
    background: rgba(255, 255, 255, 0.06);
    border-color: rgba(255, 107, 107, 0.25);
    transform: translateX(4px);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
}

.grammar-lesson-item:hover::before {
    opacity: 1;
}

.grammar-lesson-item.completed {
    border-color: rgba(6, 182, 212, 0.25);
    background: rgba(6, 182, 212, 0.04);
}

.grammar-lesson-item.completed::before {
    background: linear-gradient(180deg, var(--color-success, #10b981), #059669);
    opacity: 1;
}

.grammar-lesson-item.completed .grammar-lesson-number {
    background: linear-gradient(135deg, var(--color-success, #10b981), #059669);
    box-shadow: 0 4px 12px rgba(6, 182, 212, 0.3);
}

.grammar-lesson-number {
    flex-shrink: 0;
    width: 40px;
    height: 40px;
    border-radius: 12px;
    background: linear-gradient(135deg, var(--color-primary-light, #fca5a5), var(--color-primary-dark, #ef4444));
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 15px;
    box-shadow: 0 4px 12px rgba(255, 107, 107, 0.25);
    transition: transform 0.2s;
}

.grammar-lesson-item:hover .grammar-lesson-number {
    transform: scale(1.08);
}

.grammar-lesson-info {
    flex: 1;
    min-width: 0;
}

.grammar-lesson-info h3 {
    margin: 0 0 4px;
    color: white;
    font-size: 16px;
    font-weight: 600;
    line-height: 1.3;
}

.grammar-lesson-info p {
    margin: 0;
    color: rgba(255, 255, 255, 0.5);
    font-size: 13px;
    display: flex;
    align-items: center;
    gap: 6px;
    flex-wrap: wrap;
}

.grammar-level-badge {
    display: inline-flex;
    align-items: center;
    padding: 2px 8px;
    border-radius: 6px;
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 0.04em;
    text-transform: uppercase;
    line-height: 1.4;
}

.grammar-level-badge.hsk-1 { background: rgba(96, 149, 192, 0.2); color: #80c0e8; }
.grammar-level-badge.hsk-2 { background: rgba(6, 182, 212, 0.2); color: #67e8f9; }
.grammar-level-badge.hsk-3 { background: rgba(6, 182, 212, 0.2); color: #67e8f9; }
.grammar-level-badge.hsk-4 { background: rgba(212, 149, 43, 0.2); color: #e8c870; }
.grammar-level-badge.hsk-5 { background: rgba(212, 107, 43, 0.2); color: #e8a870; }
.grammar-level-badge.hsk-6 { background: rgba(255, 107, 107, 0.2); color: #fca5a5; }

.grammar-lesson-arrow {
    margin-left: auto;
    color: rgba(255, 255, 255, 0.2);
    font-size: 20px;
    transition: transform 0.25s, color 0.25s;
    flex-shrink: 0;
}

.grammar-lesson-item:hover .grammar-lesson-arrow {
    color: rgba(255, 107, 107, 0.7);
    transform: translateX(4px);
}

/* --- Lesson detail card --- */
.grammar-lesson-card {
    max-width: 760px;
    margin: 0 auto;
}

.grammar-pattern-card {
    padding: 28px 28px;
    background: linear-gradient(135deg, rgba(255, 107, 107, 0.12), rgba(155, 89, 182, 0.06));
    border: 1px solid rgba(255, 107, 107, 0.2);
    border-radius: 18px;
    margin-bottom: 22px;
    text-align: center;
    position: relative;
    overflow: hidden;
    box-shadow: 0 8px 32px rgba(255, 107, 107, 0.08);
}

.grammar-pattern-card::before {
    content: '';
    position: absolute;
    inset: 0;
    background: radial-gradient(ellipse at 50% 0%, rgba(255, 107, 107, 0.1), transparent 70%);
    pointer-events: none;
}

.grammar-pattern-card .pattern-label {
    font-size: 11px;
    color: #fca5a5;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.12em;
    margin-bottom: 10px;
    position: relative;
}

.grammar-pattern-card .pattern-text {
    font-family: 'Noto Sans SC', sans-serif;
    font-size: 24px;
    color: white;
    line-height: 1.6;
    letter-spacing: 0.04em;
    position: relative;
    text-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

/* --- Pattern breakdown --- */
.pattern-breakdown {
    padding: 18px 20px;
    background: rgba(255, 255, 255, 0.02);
    border-radius: 14px;
    border: 1px solid rgba(255, 255, 255, 0.05);
    margin-bottom: 18px;
}

.pattern-breakdown .section-title {
    color: #a78bfa;
    font-size: 12px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin-bottom: 12px;
}

.breakdown-items {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.breakdown-chip {
    display: inline-flex;
    flex-direction: column;
    align-items: center;
    padding: 10px 16px;
    border-radius: 12px;
    border: 1px solid rgba(255, 255, 255, 0.08);
    transition: transform 0.2s, box-shadow 0.2s;
    min-width: 60px;
    text-align: center;
}

.breakdown-chip:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.breakdown-chip.structure {
    background: rgba(255, 107, 107, 0.1);
    border-color: rgba(255, 107, 107, 0.2);
}

.breakdown-chip.placeholder {
    background: rgba(96, 149, 192, 0.1);
    border-color: rgba(96, 149, 192, 0.2);
}

.breakdown-chip .bd-text {
    font-family: 'Noto Sans SC', sans-serif;
    font-size: 18px;
    color: white;
    font-weight: 600;
    line-height: 1.3;
}

.breakdown-chip .bd-label {
    font-size: 10px;
    color: rgba(255, 255, 255, 0.45);
    text-transform: uppercase;
    letter-spacing: 0.06em;
    margin-top: 4px;
    font-weight: 600;
}

/* --- Section titles (shared) --- */
.section-title {
    font-size: 12px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin-bottom: 10px;
}

/* --- Frequency badge --- */
.freq-badge {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.02em;
}

/* --- Explanation --- */
.grammar-explanation {
    padding: 20px 22px;
    background: rgba(96, 149, 192, 0.04);
    border-radius: 14px;
    border-left: 3px solid rgba(96, 149, 192, 0.5);
    margin-bottom: 18px;
}

.grammar-explanation .section-title {
    color: #80b8d8;
}

.grammar-explanation p {
    margin: 0;
    color: rgba(255, 255, 255, 0.78);
    font-size: 14px;
    line-height: 1.7;
}

/* --- Common mistakes --- */
.common-mistakes {
    padding: 18px 22px;
    background: rgba(212, 149, 43, 0.06);
    border-radius: 14px;
    border-left: 3px solid rgba(212, 149, 43, 0.5);
    margin-bottom: 18px;
}

.common-mistakes .section-title {
    color: #e8c870;
}

.common-mistakes p {
    margin: 0;
    color: rgba(255, 255, 255, 0.75);
    font-size: 13px;
    line-height: 1.65;
}

/* --- Examples --- */
.grammar-examples {
    margin-top: 18px;
}

.grammar-examples .section-title {
    color: #67e8f9;
}

.grammar-example-item {
    padding: 16px 18px;
    background: rgba(6, 182, 212, 0.04);
    border-radius: 12px;
    margin-bottom: 10px;
    border-left: 3px solid rgba(6, 182, 212, 0.4);
    transition: background 0.2s, transform 0.2s;
}

.grammar-example-item:hover {
    background: rgba(6, 182, 212, 0.08);
    transform: translateX(2px);
}

.grammar-example-item .ex-cn {
    font-family: 'Noto Sans SC', sans-serif;
    font-size: 19px;
    color: white;
    margin-bottom: 6px;
    font-weight: 500;
}

.grammar-example-item .ex-py {
    color: rgba(255, 255, 255, 0.5);
    font-size: 13px;
    font-style: italic;
    margin-bottom: 4px;
    letter-spacing: 0.02em;
}

.grammar-example-item .ex-meaning {
    color: rgba(255, 255, 255, 0.72);
    font-size: 13px;
}

/* --- Practice stage --- */
.grammar-practice-stage {
    max-width: 640px;
    margin: 0 auto;
}

.grammar-question-card {
    padding: 32px 28px;
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.05), rgba(255, 255, 255, 0.02));
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 20px;
    text-align: center;
    margin-bottom: 20px;
    position: relative;
    overflow: hidden;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
}

.grammar-question-card::before {
    content: '';
    position: absolute;
    inset: 0;
    background: radial-gradient(ellipse at 50% 0%, rgba(255, 107, 107, 0.06), transparent 60%);
    pointer-events: none;
}

.grammar-question-card .q-eyebrow {
    color: rgba(255, 255, 255, 0.5);
    font-size: 12px;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: 14px;
    font-weight: 600;
    position: relative;
}

.grammar-question-card .q-cn {
    font-family: 'Noto Sans SC', sans-serif;
    font-size: 30px;
    color: white;
    line-height: 1.5;
    letter-spacing: 0.04em;
    position: relative;
    text-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

.grammar-options {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
}

.grammar-option {
    padding: 18px 16px;
    background: rgba(255, 255, 255, 0.04);
    border: 2px solid rgba(255, 255, 255, 0.08);
    border-radius: 14px;
    text-align: center;
    cursor: pointer;
    transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    font-family: 'Noto Sans SC', sans-serif;
    font-size: 20px;
    color: white;
    position: relative;
    overflow: hidden;
}

.grammar-option::before {
    content: '';
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at 50% 50%, rgba(255, 255, 255, 0.06), transparent 70%);
    opacity: 0;
    transition: opacity 0.25s;
}

.grammar-option:hover {
    background: rgba(255, 255, 255, 0.08);
    border-color: rgba(255, 255, 255, 0.2);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.15);
}

.grammar-option:hover::before {
    opacity: 1;
}

.grammar-option.selected {
    border-color: var(--color-primary-light, #fca5a5);
    background: rgba(255, 107, 107, 0.12);
    box-shadow: 0 0 0 3px rgba(255, 107, 107, 0.15);
}

.grammar-option.correct {
    border-color: var(--color-success, #10b981);
    background: rgba(6, 182, 212, 0.15);
    color: #67e8f9;
    box-shadow: 0 0 0 3px rgba(6, 182, 212, 0.15);
}

.grammar-option.incorrect {
    border-color: var(--color-danger, #ff6b6b);
    background: rgba(255, 107, 107, 0.15);
    color: #fca5a5;
    box-shadow: 0 0 0 3px rgba(255, 107, 107, 0.1);
}

.grammar-option.locked {
    pointer-events: none;
}

.grammar-option.locked:not(.selected):not(.correct):not(.incorrect) {
    opacity: 0.5;
}

/* ===== Speaking ===== */
.speaking-stage {
    max-width: 580px;
    margin: 0 auto;
    text-align: center;
}

.speaking-display {
    padding: 36px 24px;
    background: linear-gradient(135deg, rgba(255, 107, 107, 0.1), rgba(155, 89, 182, 0.06));
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 22px;
    margin-bottom: 22px;
}

.speaking-display .sp-cn {
    font-family: 'Noto Sans SC', sans-serif;
    font-size: 48px;
    color: white;
    margin-bottom: 12px;
    line-height: 1.3;
    letter-spacing: 0.03em;
}

.speaking-display .sp-py {
    color: rgba(255, 255, 255, 0.65);
    font-size: 18px;
    font-style: italic;
    margin-bottom: 12px;
}

.speaking-display .sp-meaning {
    color: rgba(255, 255, 255, 0.8);
    font-size: 16px;
}

.tone-display {
    display: flex;
    justify-content: center;
    gap: 12px;
}

.tone-display .tone-number {
    width: 64px;
    height: 64px;
    border-radius: 16px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: rgba(255, 255, 255, 0.04);
    border: 2px solid rgba(255, 255, 255, 0.08);
    cursor: pointer;
    transition: all 0.2s;
    color: white;
}

.tone-display .tone-number:hover {
    background: rgba(255, 255, 255, 0.1);
    transform: translateY(-2px);
}

.tone-display .tone-number.active {
    background: linear-gradient(135deg, var(--color-primary-light, #fca5a5), var(--color-primary-dark, #ef4444));
    border-color: var(--color-primary-light, #fca5a5);
    color: white;
    box-shadow: 0 6px 20px rgba(255, 107, 107, 0.4);
}

.tone-display .tone-number .tone-num {
    font-size: 24px;
    font-weight: 700;
}

.tone-display .tone-number .tone-mark {
    font-size: 18px;
    margin-top: 2px;
}

.tone-1 .tone-mark::after { content: '¯'; }
.tone-2 .tone-mark::after { content: '´'; }
.tone-3 .tone-mark::after { content: 'ˇ'; }
.tone-4 .tone-mark::after { content: '`'; }

.speaking-actions {
    display: flex;
    justify-content: center;
    gap: 12px;
    flex-wrap: wrap;
    margin-top: 14px;
}

.speaking-progress {
    text-align: center;
    padding: 8px 0;
}

.speaking-progress .progress-label {
    display: inline-block;
    padding: 4px 14px;
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 999px;
    color: rgba(255, 255, 255, 0.5);
    font-size: 12px;
    font-weight: 600;
    letter-spacing: 0.04em;
}

/* ===== Vocabulary learner enhancements ===== */
.level-card {
    text-align: center;
}

.level-card .level-stats {
    margin-top: 6px;
    font-size: 11px;
    color: rgba(255, 255, 255, 0.5);
}

.flashcard-character {
    letter-spacing: 0.04em;
}

.rating-btn {
    font-family: 'Inter', sans-serif;
}

/* ===== Animations ===== */
@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(12px); }
    to { opacity: 1; transform: translateY(0); }
}

/* ===== Module menu grids ===== */
.listening-menu,
.reading-menu,
.speaking-menu,
.grammar-menu {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    gap: 16px;
    margin: 0 auto;
}

.exercise-type-card {
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 16px;
    padding: 22px 18px;
    text-align: center;
    cursor: pointer;
    transition: all 0.2s;
    position: relative;
    overflow: hidden;
}

.exercise-type-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--color-primary-light, #fca5a5), var(--color-primary-dark, #ef4444));
    opacity: 0;
    transition: opacity 0.2s;
}

.exercise-type-card:hover {
    background: rgba(255, 255, 255, 0.08);
    border-color: rgba(255, 255, 255, 0.15);
    transform: translateY(-3px);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.25);
}

.exercise-type-card:hover::before {
    opacity: 1;
}

.exercise-type-card .type-icon {
    font-size: 36px;
    margin-bottom: 8px;
}

.exercise-type-card h3 {
    margin: 0 0 6px;
    color: white;
    font-size: 17px;
    font-weight: 600;
}

.exercise-type-card p {
    margin: 0 0 10px;
    color: rgba(255, 255, 255, 0.6);
    font-size: 13px;
    line-height: 1.45;
}

.exercise-type-card .type-difficulty {
    display: inline-block;
    padding: 3px 10px;
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.7);
    font-size: 11px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* ===== Exercise container header ===== */
.exercise-container {
    max-width: 900px;
    margin: 0 auto;
}

.exercise-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 14px;
    margin-bottom: 18px;
    padding: 14px 16px;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.06);
    border-radius: 14px;
}

.exercise-title {
    flex: 1;
    text-align: center;
    color: white;
    font-weight: 600;
    font-size: 16px;
}

.exercise-progress {
    color: rgba(255, 255, 255, 0.6);
    font-size: 13px;
    font-weight: 500;
    padding: 6px 14px;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 999px;
    font-variant-numeric: tabular-nums;
}

.exercise-controls {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-top: 22px;
    flex-wrap: wrap;
}

/* ===== Activity buttons ===== */
.btn {
    padding: 8px 16px;
    border-radius: 12px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    border: 1px solid rgba(255, 255, 255, 0.1);
    background: rgba(255, 255, 255, 0.05);
    color: rgba(255, 255, 255, 0.85);
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-family: inherit;
}

.btn:hover {
    background: rgba(255, 255, 255, 0.1);
    transform: translateY(-1px);
}

.btn:active {
    transform: translateY(0);
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none !important;
}

.btn-primary {
    background: linear-gradient(135deg, var(--color-primary-light, #fca5a5), var(--color-primary-dark, #ef4444));
    border-color: var(--color-primary-light, #fca5a5);
    color: white;
    font-weight: 600;
    box-shadow: 0 4px 14px rgba(255, 107, 107, 0.3);
}

.btn-primary:hover {
    background: linear-gradient(135deg, var(--color-primary-light, #fca5a5), var(--color-primary-dark, #ef4444));
    box-shadow: 0 6px 20px rgba(255, 107, 107, 0.45);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.05);
    border-color: rgba(255, 255, 255, 0.15);
}

.btn-success {
    background: linear-gradient(135deg, var(--color-success, #10b981), var(--color-success-dark, #059669));
    border-color: var(--color-success, #10b981);
    color: white;
}

/* Hide the legacy top-level Listen-Again button; the activity cards have their own. */
#listen-again-btn {
    display: none;
}

/* ===== MINIMAL CHILL ACTIVITY MICRO-INTERACTIONS ===== */
.listening-option, .option-card, .exercise-type-card, .matching-card, .flashcard, .btn, .choice-btn {
    transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1), 
                background 0.25s ease, 
                border-color 0.25s ease, 
                box-shadow 0.25s cubic-bezier(0.16, 1, 0.3, 1) !important;
}

.listening-option:hover, .option-card:hover, .exercise-type-card:hover {
    transform: translateY(-2px) scale(1.01);
    box-shadow: 0 12px 28px rgba(0, 0, 0, 0.35), 0 0 16px rgba(53, 223, 177, 0.12);
}

.listening-option:active, .option-card:active, .exercise-type-card:active {
    transform: translateY(0) scale(0.98);
}

.listening-option.selected, .option-card.selected {
    box-shadow: 0 0 20px rgba(250, 74, 67, 0.25), inset 0 0 12px rgba(250, 74, 67, 0.1);
}

.listening-option.correct, .option-card.correct {
    box-shadow: 0 0 24px rgba(53, 223, 177, 0.35), inset 0 0 16px rgba(53, 223, 177, 0.15);
    animation: chillPulse 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

@keyframes chillPulse {
    0% { transform: scale(1); }
    50% { transform: scale(1.03); }
    100% { transform: scale(1); }
}