/* ===== Language Buttons ===== */
.lang-buttons {
    display: flex;
    gap: 14px;
    flex-wrap: wrap;
}

.lang-btn {
    flex: 1;
    min-width: 140px;
    color: #fff;
    font-weight: bold;
    border: none;
    padding: 28px 16px;
    border-radius: 14px;
    font-size: 1.1rem;
    cursor: pointer;
    transition: all 0.3s;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    position: relative;
    overflow: hidden;
    background: linear-gradient(135deg, var(--accent-pink), var(--accent-purple));
    box-shadow: 0 4px 25px rgba(var(--accent-pink-rgb), 0.35);
}

.lang-btn::after {
    content: '';
    position: absolute;
    top: -50%; left: -50%;
    width: 200%; height: 200%;
    background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, transparent 70%);
    opacity: 0;
    transition: opacity 0.3s;
}
.lang-btn:hover::after { opacity: 1; }

@media (hover: hover) and (pointer: fine) {
    .lang-btn:hover {
        transform: translateY(-4px) scale(1.02);
    }
}
.lang-btn:active {
    transform: translateY(0) scale(0.97);
}

.lang-flag {
    width: 42px;
    height: 28px;
    object-fit: cover;
    border-radius: 4px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.3);
    border: 1px solid rgba(255,255,255,0.2);
}

/* ===== Input ===== */
.input-group {
    display: flex;
    gap: 10px;
}

.input-group input {
    flex: 1;
    padding: 11px 14px;
    border-radius: 8px;
    border: 1px solid var(--border-input);
    background-color: var(--bg-input);
    color: var(--text);
    font-size: 0.9rem;
    transition: all 0.3s;
}
.input-group input:focus {
    outline: none;
    border-color: var(--accent-light-purple);
    box-shadow: 0 0 15px rgba(192,132,252,0.25);
}

.input-group button,
.mode-card button {
    background: linear-gradient(135deg, var(--accent-pink), var(--accent-light-purple));
    color: #fff;
    font-weight: bold;
    border: none;
    padding: 11px 20px;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.25s;
    position: relative;
    overflow: hidden;
}
.input-group button:hover,
.mode-card button:hover {
    box-shadow: 0 0 20px rgba(244,114,182,0.35);
    transform: translateY(-2px);
}

.status {
    font-size: 0.85rem;
    color: var(--text-accent);
    margin-top: 10px;
    margin-bottom: 0;
    text-align: center;
}

.mode-buttons {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.mode-btn {
    flex: 1;
    min-width: 140px;
    padding: 14px 10px !important;
    font-size: 0.95rem !important;
    border-radius: 10px !important;
    border: 2px solid var(--border-card);
    transition: all 0.2s;
}
.mode-btn-active {
    border-color: var(--accent-pink) !important;
    background: rgba(var(--accent-pink-rgb),0.2) !important;
    box-shadow: 0 0 20px rgba(244,114,182,0.35);
}
.count-btn { min-width: 80px; }

/* ===== Quiz Card ===== */
.quiz-card {
    position: relative;
    background: var(--bg-card);
    backdrop-filter: blur(10px);
    padding: 30px;
    border-radius: 16px;
    border: 1px solid var(--border-card);
    box-shadow: var(--shadow-card), var(--shadow-card-inset);
    text-align: center;
    margin-bottom: 20px;
}

/* ===== Result Card ===== */
.result-card-enter {
    animation: resultCardIn 250ms cubic-bezier(0.77,0,0.175,1);
}
@keyframes resultCardIn {
    from { opacity: 0; transform: translateY(8px); }
    to   { opacity: 1; transform: translateY(0); }
}
@media (prefers-reduced-motion: reduce) {
    .result-card-enter { animation-duration: 100ms; }
}

.result-summary {
    margin: 20px 0;
}
.result-stats {
    display: flex;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
}
.stat {
    background: var(--bg-stat);
    border-radius: 12px;
    padding: 12px 20px;
    font-size: 1rem;
    font-weight: 600;
    min-width: 80px;
}
.correct-stat { color: var(--accent-green); border: 1px solid rgba(110,231,183,0.3); }
.wrong-stat { color: var(--accent-red); border: 1px solid rgba(252,165,165,0.3); }
.score-stat { color: var(--text-accent); border: 1px solid rgba(200,162,224,0.3); }
.pct-stat { color: var(--accent-yellow); border: 1px solid rgba(251,191,36,0.3); font-size: 1.2rem; }

.result-detail {
    max-height: 400px;
    overflow-y: auto;
    margin: 15px 0;
    border-radius: 10px;
    border: 1px solid var(--border-subtle);
}
.result-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.85rem;
}
.result-table th {
    position: sticky;
    top: 0;
    background: var(--bg-result-th);
    color: var(--text-accent);
    padding: 10px 12px;
    text-align: left;
    border-bottom: 2px solid var(--border-card);
}
.result-table td {
    padding: 8px 12px;
    border-bottom: 1px solid var(--border-subtle);
}
.result-table tr.result-correct td { color: var(--accent-green); }
.result-table tr.result-wrong td { color: var(--accent-red); }
.result-table tr.result-wrong td:first-child { text-decoration: line-through; opacity: 0.8; }

.quiz-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: var(--text-accent);
    font-size: 0.85rem;
    border-bottom: 1px solid var(--border-subtle);
    padding-bottom: 12px;
    margin-bottom: 10px;
    flex-wrap: wrap;
    gap: 4px;
}

.auto-speak-btn {
    background: var(--bg-stat);
    border: 1px solid var(--border-card);
    color: var(--text-accent);
    border-radius: 8px;
    padding: 4px 10px;
    font-size: 0.8rem;
    cursor: pointer;
    transition: all 0.2s;
}
.auto-speak-btn:hover { background: rgba(var(--accent-pink-rgb),0.15); }
.auto-speak-btn.speak-active { background: rgba(var(--accent-pink-rgb),0.2); border-color: var(--accent-pink); color: var(--text-pink); }

.question-row {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
}
.speak-btn {
    background: var(--bg-stat);
    border: 1px solid var(--border-card);
    color: var(--text-accent);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    font-size: 1.2rem;
    cursor: pointer;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
}
.speak-btn:hover { background: rgba(var(--accent-pink-rgb),0.2); border-color: var(--accent-pink); transform: scale(1.1); }
.speak-btn:active { transform: scale(0.95); }

.question-box {
    margin: 20px 0 15px;
    position: relative;
}

.question-deco {
    color: var(--text-pink);
    font-size: 0.9rem;
    margin-bottom: 8px;
    animation: twinkle 2s ease-in-out infinite;
}

.question-box h2 {
    font-size: 3.2rem;
    margin: 0;
    background: linear-gradient(180deg, var(--text) 30%, var(--text-pink) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    filter: drop-shadow(0 2px 10px rgba(244,114,182,0.3));
}

.hint {
    color: var(--text-hint);
    font-size: 1.05rem;
    margin-top: 10px;
}

.options-divider {
    width: 60px;
    height: 2px;
    background: linear-gradient(90deg, transparent, var(--accent-pink), transparent);
    margin: 0 auto 18px;
}

.options-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
    margin-bottom: 20px;
}

.option-btn {
    background: var(--bg-option);
    color: var(--text);
    border: 2px solid var(--border-option);
    border-radius: 12px;
    padding: 15px 12px;
    font-size: 1.05rem;
    cursor: pointer;
    transition: all 0.25s ease;
    text-align: center;
    word-break: break-word;
    position: relative;
    overflow: hidden;
}

.option-btn::before {
    content: '';
    position: absolute;
    top: 0; left: -100%;
    width: 100%; height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.05), transparent);
    transition: left 0.5s;
}
.option-btn:disabled { cursor: default; }

@media (hover: hover) and (pointer: fine) {
    .option-btn:hover::before { left: 100%; }

    .option-btn:hover:not(:disabled) {
        border-color: var(--accent-pink);
        background: var(--bg-option-hover);
        box-shadow: 0 0 20px rgba(244,114,182,0.2);
        transform: translateY(-3px);
    }
}

.option-btn.correct-choice {
    background: linear-gradient(135deg, #059669, #10b981, #34d399);
    color: #fff;
    border-color: #10b981;
    font-weight: bold;
    box-shadow: 0 0 25px rgba(16,185,129,0.4);
    animation: correctPulse 0.5s ease;
}

.option-btn.wrong-choice {
    background: linear-gradient(135deg, #dc2626, #ef4444, #f87171);
    color: #fff;
    border-color: #ef4444;
    box-shadow: 0 0 25px rgba(239,68,68,0.4);
    animation: wrongShake 0.4s ease;
}

@keyframes correctPulse {
    0% { transform: scale(1); }
    50% { transform: scale(1.05); }
    100% { transform: scale(1); }
}

@keyframes wrongShake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-6px); }
    75% { transform: translateX(6px); }
}

@media (prefers-reduced-motion: reduce) {
    .option-btn.correct-choice, .option-btn.wrong-choice { animation: none; }
}

.feedback {
    font-size: 1.15rem;
    font-weight: bold;
    white-space: pre-line;
    min-height: 30px;
    margin-bottom: 15px;
}
.feedback.correct { color: #34d399; }
.feedback.wrong   { color: #f87171; }

.action-buttons {
    display: flex;
    justify-content: center;
    gap: 12px;
    flex-wrap: wrap;
    margin-top: 20px;
}

.share-btn {
    background: linear-gradient(135deg, var(--accent-pink), var(--accent-purple));
    color: #fff;
    font-weight: bold;
    border: none;
    padding: 11px 26px;
    border-radius: 22px;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.3s;
    box-shadow: 0 0 15px rgba(var(--accent-pink-rgb),0.25);
}
.share-btn:hover {
    box-shadow: 0 0 25px rgba(var(--accent-pink-rgb),0.45);
    transform: translateY(-2px);
}

.next-btn {
    background: linear-gradient(135deg, var(--accent-pink), var(--accent-light-purple));
    color: #fff;
    font-weight: bold;
    border: none;
    padding: 11px 30px;
    border-radius: 22px;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.3s;
    box-shadow: 0 0 15px rgba(244,114,182,0.25);
}
.next-btn:hover {
    box-shadow: 0 0 25px rgba(244,114,182,0.45);
    transform: translateY(-2px);
}

.back-btn {
    background: transparent;
    color: var(--text-accent);
    border: 1px solid var(--border-card);
    padding: 11px 22px;
    border-radius: 22px;
    font-size: 0.9rem;
    cursor: pointer;
    transition: all 0.3s;
}
.back-btn:hover {
    color: var(--text);
    border-color: var(--accent-purple);
    box-shadow: 0 0 15px rgba(168,85,247,0.2);
}

/* ===== Quiz Tools (Mistake / Stats) ===== */
.quiz-tools {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    justify-content: center;
    margin-top: 18px;
}
.tool-btn {
    background: rgba(var(--accent-purple-rgb),0.08);
    color: var(--text-accent);
    border: 1px solid var(--border-card);
    padding: 9px 20px;
    border-radius: 20px;
    font-size: 0.9rem;
    cursor: pointer;
    transition: all 0.3s;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}
@media (hover: hover) and (pointer: fine) {
    .tool-btn:hover {
        color: var(--text);
        border-color: var(--accent-purple);
        background: rgba(var(--accent-purple-rgb),0.18);
        transform: translateY(-2px);
    }
}
.tool-badge {
    background: var(--accent-pink);
    color: #fff;
    font-size: 0.72rem;
    font-weight: bold;
    border-radius: 10px;
    padding: 1px 7px;
    min-width: 18px;
}

/* ===== Mistake Notebook ===== */
.mistake-empty {
    text-align: center;
    color: var(--text-accent);
    padding: 25px 0;
    font-size: 0.95rem;
}
.mistake-group {
    margin-bottom: 22px;
    text-align: left;
}
.mistake-group-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 8px;
    padding: 8px 12px;
    background: var(--bg-mistake-header);
    border-radius: 10px;
    margin-bottom: 8px;
}
.mistake-group-name {
    font-weight: bold;
    color: var(--text-pink);
}
.mistake-group-actions {
    display: flex;
    gap: 8px;
    align-items: center;
}
.mistake-review-btn {
    background: linear-gradient(135deg, var(--accent-pink), var(--accent-light-purple));
    color: #fff;
    border: none;
    padding: 6px 14px;
    border-radius: 14px;
    font-size: 0.82rem;
    cursor: pointer;
    transition: all 0.3s;
}
.mistake-review-btn:hover {
    box-shadow: 0 0 12px rgba(244,114,182,0.4);
    transform: translateY(-1px);
}
.mistake-clear-btn {
    background: transparent;
    color: var(--text-dim2);
    border: 1px solid var(--border-subtle);
    padding: 6px 12px;
    border-radius: 14px;
    font-size: 0.78rem;
    cursor: pointer;
    transition: all 0.3s;
}
.mistake-clear-btn:hover {
    color: #ff8fa3;
    border-color: rgba(255,82,82,0.4);
}
.mistake-need4 {
    font-size: 0.75rem;
    color: var(--text-dim2);
}
.mistake-items {
    display: flex;
    flex-direction: column;
    gap: 5px;
}
.mistake-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 7px 12px;
    background: var(--bg-mistake-item);
    border: 1px solid var(--border-section);
    border-radius: 8px;
    font-size: 0.9rem;
}
.mistake-word {
    font-weight: bold;
    color: var(--text);
    min-width: 90px;
}
.mistake-answer {
    color: var(--text-accent);
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}
.mistake-count {
    color: var(--accent-pink);
    font-size: 0.8rem;
    font-weight: bold;
}
.mistake-del {
    background: transparent;
    border: none;
    color: var(--text-dim2);
    cursor: pointer;
    font-size: 0.85rem;
    padding: 2px 6px;
    border-radius: 6px;
    transition: all 0.2s;
}
.mistake-del:hover {
    color: #ff5252;
    background: rgba(255,82,82,0.1);
}
.mistake-pagination {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 14px;
    margin-top: 10px;
}
.mistake-page-btn {
    background: rgba(var(--accent-purple-rgb),0.1);
    color: var(--text-accent);
    border: 1px solid var(--border-card);
    padding: 6px 16px;
    border-radius: 18px;
    font-size: 0.82rem;
    cursor: pointer;
    transition: all 0.25s;
}
.mistake-page-btn:hover:not(:disabled) {
    background: rgba(var(--accent-purple-rgb),0.25);
    color: var(--text);
    border-color: var(--accent-purple);
    transform: translateY(-1px);
}
.mistake-page-btn:disabled {
    opacity: 0.3;
    cursor: default;
}
.mistake-page-info {
    color: var(--text-dim2);
    font-size: 0.82rem;
    min-width: 40px;
    text-align: center;
}

/* ===== Quiz Stats ===== */
.stats-summary {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(110px, 1fr));
    gap: 12px;
    margin-bottom: 20px;
}
.stats-tile {
    background: var(--bg-stats-tile);
    border: 1px solid var(--border-section);
    border-radius: 12px;
    padding: 14px 8px;
    text-align: center;
}
.stats-num {
    font-size: 1.5rem;
    font-weight: bold;
    background: linear-gradient(135deg, var(--accent-pink), var(--accent-light-purple));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}
.stats-label {
    font-size: 0.78rem;
    color: var(--text-accent);
    margin-top: 4px;
}
.stats-chart-title {
    text-align: left;
    color: var(--text-pink);
    font-weight: bold;
    font-size: 0.92rem;
    margin: 16px 0 8px;
}
.stats-chart {
    background: var(--bg-stats-chart);
    border: 1px solid var(--border-section);
    border-radius: 12px;
    padding: 10px;
}
.stats-chart svg {
    width: 100%;
    height: 130px;
    display: block;
}
.achievement-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: 10px;
}
.achievement-badge {
    background: var(--bg-stats-tile);
    border: 1px solid var(--border-section);
    border-radius: 12px;
    padding: 12px 8px;
    text-align: center;
    transition: transform 0.2s;
}
.achievement-badge:not(.locked):hover {
    transform: translateY(-2px);
}
.achievement-badge.locked {
    opacity: 0.35;
    filter: grayscale(1);
}
.achievement-icon {
    font-size: 1.6rem;
}
.achievement-title {
    font-size: 0.82rem;
    font-weight: bold;
    color: var(--text-pink);
    margin-top: 4px;
}
.achievement-desc {
    font-size: 0.7rem;
    color: var(--text-accent);
    margin-top: 2px;
}
.streak-display {
    text-align: center;
    margin-top: 14px;
    font-size: 0.9rem;
    font-weight: bold;
    color: var(--text-pink);
}
.streak-display span#streak-count {
    font-size: 1.05rem;
}
.stats-table {
    width: 100%;
}

/* ===== Share Toast ===== */
.share-toast {
    position: fixed;
    bottom: 90px;
    left: 50%;
    transform: translateX(-50%) translateY(20px);
    background: linear-gradient(135deg, var(--accent-pink), var(--accent-purple));
    color: #fff;
    padding: 12px 28px;
    border-radius: 24px;
    font-size: 0.95rem;
    font-weight: 600;
    opacity: 0;
    pointer-events: none;
    transition: all 0.35s ease;
    z-index: 9999;
    box-shadow: 0 4px 20px rgba(var(--accent-purple-rgb),0.4);
    white-space: nowrap;
}
.share-toast.show {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
}

/* ===== Timer ===== */
.timer-display {
    background: rgba(251,191,36,0.15);
    color: #fbbf24;
    padding: 4px 12px;
    border-radius: 12px;
    font-weight: 700;
    font-size: 0.95rem;
    min-width: 50px;
    text-align: center;
}
.timer-bar-container {
    width: 100%;
    height: 4px;
    background: rgba(255,255,255,0.08);
    border-radius: 2px;
    margin-top: -8px;
    margin-bottom: 12px;
    overflow: hidden;
}
.timer-bar {
    height: 100%;
    width: 100%;
    background: #6ee7b7;
    border-radius: 2px;
}

/* ===== Flashcard ===== */
.flashcard-container {
    position: relative;
    perspective: 800px;
    width: 100%;
    max-width: 360px;
    height: 220px;
    margin: 20px auto;
}
.flashcard-speak-btn {
    position: absolute;
    top: 8px;
    right: 8px;
    z-index: 5;
    width: 34px;
    height: 34px;
    font-size: 1rem;
}
.flashcard {
    width: 100%;
    height: 100%;
    position: relative;
    transform-style: preserve-3d;
    transition: transform 350ms cubic-bezier(0.77,0,0.175,1);
    cursor: pointer;
}
.flashcard.flipped {
    transform: rotateY(180deg);
}
@media (prefers-reduced-motion: reduce) {
    .flashcard { transition-duration: 0.15s; }
}
.flashcard-front, .flashcard-back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    border-radius: 16px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 20px;
    box-sizing: border-box;
}
.flashcard-front {
    background: linear-gradient(135deg, rgba(192,132,252,0.15), rgba(244,114,182,0.15));
    border: 1px solid rgba(192,132,252,0.3);
}
.flashcard-back {
    background: linear-gradient(135deg, rgba(110,231,183,0.12), rgba(96,165,250,0.12));
    border: 1px solid rgba(110,231,183,0.3);
    transform: rotateY(180deg);
}
.flashcard-word {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text);
    text-align: center;
    line-height: 1.3;
}
.flashcard-sub {
    font-size: 1rem;
    color: var(--text-muted, rgba(255,255,255,0.5));
    margin-top: 8px;
    text-align: center;
}
.flashcard-nav {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 20px;
    margin: 12px 0;
}
.flashcard-nav span {
    color: var(--text-muted, rgba(255,255,255,0.5));
    font-size: 0.9rem;
    min-width: 60px;
    text-align: center;
}
.flashcard-actions {
    display: flex;
    gap: 12px;
    justify-content: center;
    margin-top: 8px;
}
.flashcard-known {
    background: rgba(110,231,183,0.15);
    color: #6ee7b7;
    border: 1px solid rgba(110,231,183,0.3);
    padding: 8px 20px;
    border-radius: 20px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
}
.flashcard-known:hover {
    background: rgba(110,231,183,0.25);
}
.flashcard-unknown {
    background: rgba(248,113,113,0.15);
    color: #f87171;
    border: 1px solid rgba(248,113,113,0.3);
    padding: 8px 20px;
    border-radius: 20px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
}
.flashcard-unknown:hover {
    background: rgba(248,113,113,0.25);
}

/* ===== Listening Quiz ===== */
.listening-input-group {
    display: flex;
    gap: 10px;
    justify-content: center;
    align-items: center;
    margin: 20px 0;
}
.listening-input {
    background: var(--bg-input, rgba(255,255,255,0.06));
    border: 2px solid rgba(192,132,252,0.3);
    border-radius: 12px;
    color: var(--text);
    padding: 12px 18px;
    font-size: 1.1rem;
    width: 260px;
    max-width: 100%;
    outline: none;
    transition: border-color 0.3s;
    text-align: center;
}
.listening-input:focus {
    border-color: rgba(192,132,252,0.6);
    box-shadow: 0 0 12px rgba(192,132,252,0.15);
}
.listening-input:disabled {
    opacity: 0.6;
}