/* Quiz-specific styles - uses CSS variables from styles.css */

/* ============================================
   LIGHT THEME (default)
   ============================================ */
:root,
.theme-light {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --success-color: #16a34a;
    --warning-color: #d97706;
    --error-color: #dc2626;
    --background: #f8fafc;
    --surface: #ffffff;
    --surface-elevated: #ffffff;
    --border: #e2e8f0;
    --text-primary: #1e293b;
    --text-secondary: #475569;
    --text-muted: #64748b;
    --diagram-bg: #ffffff;
    --diagram-grid: #e0e0e0;
    --diagram-text: #333333;
    --diagram-c0: #ef4444;
    --diagram-c90: #3b82f6;
}

/* ============================================
   DARK THEME
   ============================================ */
.theme-dark {
    --primary-color: #60a5fa;
    --primary-hover: #3b82f6;
    --success-color: #4ade80;
    --warning-color: #fbbf24;
    --error-color: #f87171;
    --background: #0f172a;
    --surface: #1e293b;
    --surface-elevated: #334155;
    --border: #475569;
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-muted: #94a3b8;
    --diagram-bg: #1a1a2e;
    --diagram-grid: #404060;
    --diagram-text: #e0e0e0;
    --diagram-c0: #f87171;
    --diagram-c90: #60a5fa;
}

/* ============================================
   BASE LAYOUT
   ============================================ */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    background: var(--background);
    color: var(--text-primary);
    min-height: 100vh;
}

.quiz-app {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    background: var(--background);
    color: var(--text-primary);
}

/* ============================================
   HEADER
   ============================================ */
.quiz-header {
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    padding: 1rem 1.5rem;
}

.header-content {
    max-width: 800px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.header-title {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.header-icon {
    font-size: 1.5rem;
}

.header-controls {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.language-selector {
    padding: 0.4rem 0.5rem;
    border: 1px solid var(--border);
    border-radius: 8px;
    background: var(--surface);
    color: var(--text-primary);
    font-size: 0.85rem;
    cursor: pointer;
    outline: none;
}

.language-selector:hover {
    border-color: var(--primary-color);
}

.language-selector:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px rgba(37, 99, 235, 0.2);
}

.theme-toggle {
    background: none;
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 0.5rem;
    cursor: pointer;
    font-size: 1.25rem;
    line-height: 1;
}

.theme-toggle:hover {
    background: var(--surface-elevated);
}

/* ============================================
   MAIN CONTENT
   ============================================ */
.quiz-main {
    flex: 1;
    max-width: 800px;
    margin: 0 auto;
    padding: 2rem 1.5rem;
    width: 100%;
}

/* ============================================
   FOOTER
   ============================================ */
.quiz-footer {
    background: var(--surface);
    border-top: 1px solid var(--border);
    padding: 1rem 1.5rem;
    text-align: center;
    font-size: 0.85rem;
    color: var(--text-muted);
}

.footer-link {
    color: var(--primary-color);
    text-decoration: none;
}

.footer-link:hover {
    text-decoration: underline;
}

.footer-sep {
    margin: 0 0.75rem;
    color: var(--border);
}

/* ============================================
   CONFIG SCREEN
   ============================================ */
.config-screen {
    display: flex;
    justify-content: center;
}

.config-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 2rem;
    width: 100%;
    max-width: 700px;
}

.config-title {
    font-size: 1.5rem;
    margin-bottom: 0.25rem;
}

.config-subtitle {
    color: var(--text-muted);
    margin-bottom: 1.5rem;
}

.config-section {
    margin-bottom: 1.5rem;
}

.config-section h3 {
    font-size: 1rem;
    margin-bottom: 0.75rem;
    color: var(--text-secondary);
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.75rem;
}

.section-header h3 {
    margin-bottom: 0;
}

.section-actions {
    display: flex;
    gap: 0.75rem;
}

.link-btn {
    background: none;
    border: none;
    color: var(--primary-color);
    cursor: pointer;
    font-size: 0.85rem;
    padding: 0;
}

.link-btn:hover {
    text-decoration: underline;
}

/* Category grid */
.category-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 0.5rem;
}

.category-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 0.75rem;
    border: 1px solid var(--border);
    border-radius: 8px;
    cursor: pointer;
    transition: background 0.15s;
}

.category-item:hover {
    background: var(--surface-elevated);
}

.category-item input[type="checkbox"] {
    accent-color: var(--primary-color);
}

.category-label {
    flex: 1;
    font-size: 0.9rem;
}

.category-count {
    font-size: 0.75rem;
    color: var(--text-muted);
    background: var(--background);
    padding: 0.1rem 0.4rem;
    border-radius: 10px;
}

/* Difficulty radio */
.difficulty-options {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.radio-item {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    cursor: pointer;
    font-size: 0.9rem;
}

.radio-item input[type="radio"] {
    accent-color: var(--primary-color);
}

/* Question count */
.count-options {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.count-btn {
    padding: 0.5rem 1.25rem;
    border: 1px solid var(--border);
    border-radius: 8px;
    background: var(--surface);
    color: var(--text-primary);
    cursor: pointer;
    font-size: 0.9rem;
    transition: all 0.15s;
}

.count-btn:hover {
    border-color: var(--primary-color);
}

.count-btn.active {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

/* Summary */
.config-summary {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 1.5rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border);
}

.available-count {
    color: var(--text-muted);
    font-size: 0.9rem;
}

.start-btn {
    padding: 0.75rem 2rem;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.15s;
}

.start-btn:hover {
    background: var(--primary-hover);
}

.start-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

/* ============================================
   QUIZ VIEW
   ============================================ */
.quiz-view {
    max-width: 700px;
    margin: 0 auto;
}

/* Progress */
.progress-section {
    margin-bottom: 1.5rem;
}

.progress-info {
    display: flex;
    justify-content: space-between;
    margin-bottom: 0.5rem;
    font-size: 0.85rem;
}

.progress-text {
    font-weight: 600;
}

.score-text {
    color: var(--text-muted);
}

.progress-bar {
    height: 6px;
    background: var(--border);
    border-radius: 3px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: var(--primary-color);
    border-radius: 3px;
    transition: width 0.3s ease;
}

/* Question card */
.question-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 1.5rem;
}

.question-meta {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.question-category {
    font-size: 0.75rem;
    font-weight: 600;
    padding: 0.2rem 0.6rem;
    border-radius: 12px;
    background: var(--primary-color);
    color: white;
}

.question-difficulty {
    font-size: 0.75rem;
    font-weight: 600;
    padding: 0.2rem 0.6rem;
    border-radius: 12px;
}

.diff-beginner {
    background: #dcfce7;
    color: #166534;
}
.theme-dark .diff-beginner {
    background: #14532d;
    color: #86efac;
}

.diff-intermediate {
    background: #fef3c7;
    color: #92400e;
}
.theme-dark .diff-intermediate {
    background: #78350f;
    color: #fde68a;
}

.diff-expert {
    background: #fee2e2;
    color: #991b1b;
}
.theme-dark .diff-expert {
    background: #7f1d1d;
    color: #fca5a5;
}

.question-text {
    font-size: 1.1rem;
    line-height: 1.5;
    margin-bottom: 1.25rem;
}

/* Diagrams */
.question-diagram {
    margin-bottom: 1.25rem;
    display: flex;
    justify-content: center;
}

.diagram-pair {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    justify-content: center;
}

.diagram-single {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.diagram-item {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.diagram-label {
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-bottom: 0.5rem;
    font-weight: 500;
}

/* Options */
.options-list {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.option-btn {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    padding: 0.75rem 1rem;
    border: 2px solid var(--border);
    border-radius: 8px;
    background: var(--surface);
    color: var(--text-primary);
    cursor: pointer;
    text-align: left;
    font-size: 0.95rem;
    transition: all 0.15s;
    width: 100%;
}

.option-btn:hover:not(:disabled) {
    border-color: var(--primary-color);
    background: var(--background);
}

.option-btn.correct {
    border-color: var(--success-color);
    background: #dcfce7;
}
.theme-dark .option-btn.correct {
    background: #14532d40;
}

.option-btn.wrong {
    border-color: var(--error-color);
    background: #fee2e2;
}
.theme-dark .option-btn.wrong {
    background: #7f1d1d40;
}

.option-btn.disabled {
    opacity: 0.5;
    cursor: default;
}

.option-btn:disabled {
    cursor: default;
}

.option-letter {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 1.75rem;
    height: 1.75rem;
    border-radius: 50%;
    background: var(--background);
    border: 1px solid var(--border);
    font-weight: 700;
    font-size: 0.8rem;
    flex-shrink: 0;
    color: var(--text-secondary);
}

.option-text {
    padding-top: 0.2rem;
    line-height: 1.4;
}

/* Feedback */
.feedback {
    padding: 1rem;
    border-radius: 8px;
    margin-bottom: 1rem;
}

.feedback.correct {
    background: #dcfce7;
    border: 1px solid var(--success-color);
}
.theme-dark .feedback.correct {
    background: #14532d40;
}

.feedback.wrong {
    background: #fee2e2;
    border: 1px solid var(--error-color);
}
.theme-dark .feedback.wrong {
    background: #7f1d1d40;
}

.feedback-header {
    font-weight: 700;
    font-size: 1rem;
    margin-bottom: 0.5rem;
}

.feedback.correct .feedback-header {
    color: var(--success-color);
}

.feedback.wrong .feedback-header {
    color: var(--error-color);
}

.feedback-explanation {
    font-size: 0.9rem;
    line-height: 1.5;
    color: var(--text-secondary);
}

.feedback-reference {
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-top: 0.5rem;
}

/* Navigation */
.question-nav {
    display: flex;
    justify-content: flex-end;
    margin-top: 1rem;
}

.nav-btn {
    padding: 0.6rem 1.5rem;
    border-radius: 8px;
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.15s;
}

.nav-btn.primary {
    background: var(--primary-color);
    color: white;
    border: none;
}

.nav-btn.primary:hover {
    background: var(--primary-hover);
}

.nav-btn.secondary {
    background: none;
    border: 1px solid var(--border);
    color: var(--text-secondary);
}

.nav-btn.secondary:hover {
    border-color: var(--text-muted);
}

/* ============================================
   RESULTS SCREEN
   ============================================ */
.results-screen {
    display: flex;
    justify-content: center;
}

.results-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 2rem;
    width: 100%;
    max-width: 600px;
    text-align: center;
}

.grade-badge {
    display: inline-block;
    padding: 0.5rem 1.5rem;
    border-radius: 20px;
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
}

.grade-excellent {
    background: #dcfce7;
    color: #166534;
}
.theme-dark .grade-excellent {
    background: #14532d;
    color: #86efac;
}

.grade-good {
    background: #dbeafe;
    color: #1e40af;
}
.theme-dark .grade-good {
    background: #1e3a5f;
    color: #93c5fd;
}

.grade-ok {
    background: #fef3c7;
    color: #92400e;
}
.theme-dark .grade-ok {
    background: #78350f;
    color: #fde68a;
}

.grade-poor {
    background: #fee2e2;
    color: #991b1b;
}
.theme-dark .grade-poor {
    background: #7f1d1d;
    color: #fca5a5;
}

.score-display {
    margin-bottom: 2rem;
}

.score-pct {
    display: block;
    font-size: 3rem;
    font-weight: 800;
    color: var(--text-primary);
    line-height: 1.2;
}

.score-detail {
    display: block;
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-top: 0.25rem;
}

/* Breakdown */
.breakdown-section {
    text-align: left;
    margin-bottom: 1.5rem;
}

.breakdown-section h3 {
    font-size: 0.9rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 0.75rem;
}

.breakdown-list {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

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

.breakdown-label {
    display: flex;
    justify-content: space-between;
    font-size: 0.85rem;
}

.breakdown-score {
    color: var(--text-muted);
    font-size: 0.8rem;
}

.breakdown-bar {
    height: 6px;
    background: var(--border);
    border-radius: 3px;
    overflow: hidden;
}

.bar-fill {
    height: 100%;
    border-radius: 3px;
    transition: width 0.5s ease;
}

.bar-fill.good {
    background: var(--success-color);
}

.bar-fill.ok {
    background: var(--warning-color);
}

.bar-fill.poor {
    background: var(--error-color);
}

/* ============================================
   RESPONSIVE
   ============================================ */
@media (max-width: 600px) {
    .quiz-main {
        padding: 1rem;
    }

    .config-card,
    .results-card {
        padding: 1.25rem;
    }

    .category-grid {
        grid-template-columns: 1fr;
    }

    .diagram-pair {
        flex-direction: column;
        align-items: center;
    }

    .header-title {
        font-size: 1rem;
    }

    .config-summary {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }

    .difficulty-options {
        flex-direction: column;
        gap: 0.5rem;
    }
}