:root {
    --primary: #3b82f6;
    --primary-hover: #2563eb;
    --primary-light: #eff6ff;
    --primary-dark: #1e40af;
    --success: #10b981;
    --success-light: #d1fae5;
    --error: #ef4444;
    --error-light: #fee2e2;
    --bg: #f8fafc;
    --card-bg: #ffffff;
    --white: #ffffff;
    --border: #e2e8f0;
    --text-main: #0f172a;
    --text-secondary: #475569;
    --shadow: rgba(0, 0, 0, 0.05);
    --shadow-hover: rgba(0, 0, 0, 0.1);
    --font-main: "Times New Roman", Times, Baskerville, Georgia, serif;
}

[data-theme="dark"] {
    --primary: #60a5fa;
    --primary-hover: #3b82f6;
    --primary-light: #1e3a8a;
    --primary-dark: #93c5fd;
    --success: #34d399;
    --success-light: #064e3b;
    --error: #f87171;
    --error-light: #7f1d1d;
    --bg: #0f172a;
    --card-bg: #1e293b;
    --white: #ffffff;
    --border: #334155;
    --text-main: #f1f5f9;
    --text-secondary: #cbd5e1;
    --shadow: rgba(0, 0, 0, 0.3);
    --shadow-hover: rgba(0, 0, 0, 0.5);
}

body {
    font-family: var(--font-main) ;
    font-size: 17px;
    background-color: var(--bg);
    margin: 0;
    padding: 20px;
    color: var(--text-main);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    transition: background-color 0.3s ease, color 0.3s ease;
}
.logo-img {
    display: block;
    max-width: 200px;
    height: auto;
    margin: 1rem auto 1.5rem auto;
    transition: filter 0.3s ease;
}

[data-theme="dark"] .logo-img {
    filter: brightness(0) invert(1);
}

.card {
    background-color: var(--card-bg);
    width: 95%;
    max-width: 850px;
    border-radius: 16px;
    box-shadow: 0 10px 25px var(--shadow);
    padding: 2.5rem;
    margin: 2rem 0;
    transition: background-color 0.3s ease, box-shadow 0.3s ease;
    position: relative;
}

.card h1 {
    font-family: var(--font-main) ;
    font-size: 2.5rem;
}

.card h2 {
    font-family: var(--font-main) ;
    color: var(--text-main);
    font-size: 1.5 rem ;
    margin-bottom: 1.5rem;
    border-bottom: 2px solid var(--primary-light);
    padding-bottom: 0.5rem;
    display: inline-block;
    transition: color 0.3s ease;
}

.step-section {
    display: none;
}

.active {
    display: block;
    animation: fadeIn 0.4s ease-out;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.option-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.2rem;
    margin-top: 1.5rem;
}

.btn-choice {
    padding: 1.5rem;
    border: 2px solid var(--border);
    background: var(--card-bg);
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-family: var(--font-main) ;
    font-size: 1.3rem ;
    font-weight: 700;
    color: var(--text-main);
}

.btn-choice:hover {
    border-color: var(--primary);
    background: var(--primary-light);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px var(--shadow-hover);
}

.question-card {
    border: 1px solid var(--border);
    padding: 2rem;
    border-radius: 12px;
    margin-bottom: 1.5rem;
    background: var(--card-bg);
    transition: background-color 0.3s ease, border-color 0.3s ease;
}

.question-text {
    font-family: var(--font-main) ;
    font-size: 1.4rem ;
    line-height: 1.6;
}

.question-image {
    display: block;
    max-width: 600px;
    max-height: 400px;
    width: auto;
    height: auto;
    margin: 1.5rem auto;
    border-radius: 8px;
    border: 1px solid var(--border);
    transition: border-color 0.3s ease;
}

.passage-box {
    padding: 1.5rem;
    margin-bottom: 2rem;
    border-radius: 12px;
    border: 2px solid var(--border);
    background: var(--primary-light);
    color: var(--text-main);
    line-height: 1.8;
    transition: background-color 0.3s ease, border-color 0.3s ease, color 0.3s ease;
}

hr {
    border: none;
    border-top: 1px solid var(--border);
    margin: 2rem 0;
    transition: border-color 0.3s ease;
}

h3 {
    color: var(--text-main);
    transition: color 0.3s ease;
}

.completion-badge {
    display: inline-block;
    margin-left: 0.5rem;
    padding: 0.2rem 0.5rem;
    background: var(--success);
    color: white;
    border-radius: 12px;
    font-size: 0.75rem;
    font-weight: 700;
}

.availability-badge {
    display: inline-block;
    margin-left: 0.3rem;
    padding: 0.15rem 0.4rem;
    border-radius: 8px;
    font-size: 0.7rem;
    font-weight: 600;
    font-style: italic;
}

.availability-badge.available {
    background: var(--success-light);
    color: var(--success);
}

.availability-badge.unavailable {
    background: var(--error-light);
    color: var(--error);
}

[data-theme="dark"] .availability-badge.available {
    background: var(--success-light);
    color: var(--success);
}

[data-theme="dark"] .availability-badge.unavailable {
    background: var(--error-light);
    color: var(--error);
}

.btn-choice.completed {
    position: relative;
    background: var(--primary-light);
    border-color: var(--primary);
    border-width: 2px;
    font-weight: 700;
}

.btn-choice.unavailable {
    opacity: 0.65;
    cursor: not-allowed;
    background: var(--card-bg);
    border-color: var(--border);
    border-style: dashed;
    position: relative;
    pointer-events: none;
}

.btn-choice.unavailable:hover {
    transform: none;
    border-color: var(--border);
    background: var(--card-bg);
    box-shadow: none;
    opacity: 0.65;
}

.btn-choice.unavailable:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.btn-choice.completed:hover {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.4);
}

[data-theme="dark"] .btn-choice.completed {
    background: var(--primary-light);
    border-color: var(--primary);
    color: var(--text-main);
}

[data-theme="dark"] .btn-choice.completed:hover {
    background: var(--primary);
    color: var(--card-bg);
    border-color: var(--primary);
}

.history-grid {
    display: grid;
    gap: 1.5rem;
    margin-top: 1.5rem;
}

.history-card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 1.5rem;
    transition: all 0.3s ease;
}

.history-card:hover {
    box-shadow: 0 4px 12px var(--shadow-hover);
    transform: translateY(-2px);
}

.history-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.history-header h3 {
    margin: 0;
    font-size: 1.3rem;
    color: var(--text-main);
}

.history-date {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.history-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1rem;
}

.stat-item {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.stat-label {
    font-size: 0.85rem;
    color: var(--text-secondary);
    font-weight: 600;
}

.stat-value {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--text-main);
}

.stat-value.best-score {
    color: var(--success);
}

@media (max-width: 600px) {
    .history-header {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .history-stats {
        grid-template-columns: 1fr;
    }
}

.options-container {
    font-family: var(--font-main) ;
}

.option-label {
    display: flex;
    align-items: center;
    padding: 1.2rem;
    flex-wrap: wrap;
    margin: 0.6rem 0;
    border: 1.5px solid var(--border);
    border-radius: 10px;
    cursor: pointer;
    transition: 0.2s;
    font-size: 0.8 rem;
    background: var(--card-bg);
    color: var(--text-main);
}

.option-label:hover {
    border-color: var(--primary);
    background: var(--primary-light);
}

.option-label input {
    margin-right: 12px;
}

.option-label img {
    max-width: 300px;
    max-height: 220px;
    width: auto;
    height: auto;
    object-fit: contain;
    margin-left: 8px;
    border-radius: 4px;
}


@media (max-width: 900px) {
    .question-image { max-width: 90%; max-height: 360px; }
    .option-label img { max-width: 40%; max-height: 160px; }
    .review-image { max-width: 90%; max-height: 280px; }
}

@media (max-width: 480px) {
    .question-image { max-width: 100%; max-height: 260px; }
    .option-label img { max-width: 48%; max-height: 120px; margin-left: 6px; }
    .review-image { max-width: 100%; max-height: 200px; }
}

.score-display {
    text-align: center;
    padding: 2rem;
    background: var(--primary-light);
    border-radius: 20px;
}

.score-circle {
    font-size: 4rem;
    font-weight: 900;
    color: var(--primary);
}

button.primary-btn {
    width: 100%;
    padding: 1.2rem;
    background: var(--primary);
    color: white;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    margin-top: 1rem;
    font-family: var(--font-main) ;
    font-size: 1.2rem ;
    font-weight: 700;
    transition: background-color 0.3s ease, transform 0.2s ease, box-shadow 0.2s ease, color 0.3s ease;
}

[data-theme="dark"] button.primary-btn {
    color: white;
}

button.primary-btn:hover {
    background: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.4);
}

button.primary-btn.secondary-btn {
    background: var(--text-secondary);
}

button.primary-btn.secondary-btn:hover {
    background: var(--text-main);
    box-shadow: 0 4px 12px var(--shadow-hover);
}

[data-theme="dark"] button.primary-btn.secondary-btn {
    background: #64748b;
}

[data-theme="dark"] button.primary-btn.secondary-btn:hover {
    background: #94a3b8;
}

.review-card {
    margin-top: 1.5rem;
    padding: 1.5rem;
    border-radius: 8px;
    border: 1px solid var(--border);
    background: var(--card-bg);
    transition: background-color 0.3s ease, border-color 0.3s ease;
}

.status-correct {
    border-left: 3px solid var(--success);
    background: var(--card-bg);
}

.status-wrong {
    border-left: 3px solid var(--error);
    background: var(--card-bg);
}

.review-card .question-text {
    margin-bottom: 1rem;
    font-size: 1.2rem;
    line-height: 1.6;
}

.review-image {
    max-width: 500px;
    max-height: 375px;
    width: auto;
    height: auto;
    margin: 1rem auto;
    border-radius: 6px;
    border: 1px solid var(--border);
    display: block;
}

.review-card .image-grid {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    margin: 1rem 0;
}

.review-card .image-grid .review-image {
    margin: 0;
}

.correct-tag {
    color: var(--text-main);
    font-weight: 600;
    font-size: 1rem;
    margin-top: 0.75rem;
    padding: 0.5rem 0;
}

.correct-tag::before {
    content: "✓ ";
    color: var(--success);
    font-weight: bold;
    margin-right: 0.25rem;
}

.wrong-tag {
    color: var(--text-main);
    font-weight: 600;
    font-size: 1rem;
    margin-top: 0.75rem;
    padding: 0.5rem 0;
}

.wrong-tag::before {
    content: "✗ ";
    color: var(--error);
    font-weight: bold;
    margin-right: 0.25rem;
}

.actual-answer {
    font-size: 1rem;
    margin-top: 0.5rem;
    padding: 0.75rem;
    background: var(--primary-light);
    border-radius: 6px;
    border-left: 3px solid var(--primary);
    color: var(--text-main);
}

.theme-toggle {
    position: fixed;
    top: 20px;
    right: 20px;
    background: var(--card-bg);
    border: 2px solid var(--border);
    border-radius: 50%;
    width: 50px;
    height: 50px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
    z-index: 1000;
    box-shadow: 0 4px 12px var(--shadow);
    color: var(--text-main);
}

.theme-toggle svg {
    width: 24px;
    height: 24px;
    transition: transform 0.3s ease;
}

.theme-toggle:hover {
    border-color: var(--primary);
    background: var(--primary-light);
    transform: scale(1.1);
    box-shadow: 0 6px 16px var(--shadow-hover);
}

.theme-toggle:active {
    transform: scale(0.95);
}

* {
    transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
}

body.preload * {
    transition: none !important;
}

.nav-buttons {
    display: flex;
    gap: 1rem;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
    align-items: center;
}

.nav-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.25rem;
    border: 2px solid var(--border);
    background: var(--card-bg);
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-family: var(--font-main);
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-main);
    text-decoration: none;
    box-shadow: 0 2px 4px var(--shadow);
}

.nav-btn svg {
    flex-shrink: 0;
    transition: transform 0.3s ease;
}

.nav-btn:hover {
    border-color: var(--primary);
    background: var(--primary-light);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px var(--shadow-hover);
}

.nav-btn:hover svg {
    transform: translateX(-2px);
}

.nav-btn:active {
    transform: translateY(0);
    box-shadow: 0 2px 4px var(--shadow);
}

.back-btn {
    border-color: var(--text-secondary);
}

.back-btn:hover {
    border-color: var(--primary);
    background: var(--primary-light);
    color: var(--primary);
}

.home-btn {
    border-color: var(--primary);
    background: var(--primary-light);
    color: var(--primary);
}

.home-btn:hover {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
}

[data-theme="dark"] .home-btn {
    background: var(--primary-light);
    color: var(--primary);
    border-color: var(--primary);
}

[data-theme="dark"] .home-btn:hover {
    background: var(--primary);
    color: var(--card-bg);
}

@media (max-width: 600px) {
    .option-grid {
        grid-template-columns: 1fr;
    }
    
    .theme-toggle {
        top: 10px;
        right: 10px;
        width: 45px;
        height: 45px;
        font-size: 1.3rem;
    }
    
    .nav-buttons {
        gap: 0.75rem;
    }
    
    .nav-btn {
        padding: 0.65rem 1rem;
        font-size: 0.9rem;
    }
    
    .nav-btn svg {
        width: 18px;
        height: 18px;
    }
}