:root {
    --primary-color: #0f4c81; /* Classic professional blue */
    --primary-hover: #0a365c;
    --secondary-color: #e2e8f0;
    --secondary-hover: #cbd5e1;
    --danger-color: #ef4444;
    --danger-hover: #dc2626;
    --text-main: #1e293b;
    --text-muted: #64748b;
    --bg-main: #f8fafc;
    --bg-card: #ffffff;
    --border-color: #e2e8f0;
    --correct-bg: #dcfce7;
    --correct-border: #86efac;
    --wrong-bg: #fee2e2;
    --wrong-border: #fca5a5;
    --selected-bg: #e0f2fe;
    --selected-border: #7dd3fc;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}


body {
    min-width: 320px;
    overflow-x: hidden;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-main);
    color: var(--text-main);
    line-height: 1.6;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 20px;
}

header {
    background-color: var(--primary-color);
    color: white;
    padding: 20px 0;
    margin-bottom: 30px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

header h1 {
    font-size: 1.8rem;
    margin-bottom: 5px;
}

header p {
    opacity: 0.9;
    font-size: 0.9rem;
}

main {
    min-height: 60vh;
}

.screen {
    display: none;
    animation: fadeIn 0.3s ease-in;
}

.screen.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.info-box {
    background-color: #e0f2fe;
    border-left: 4px solid var(--primary-color);
    padding: 15px;
    margin: 20px 0;
    border-radius: 0 4px 4px 0;
}

.info-box ul {
    margin-top: 10px;
    margin-bottom: 10px;
    padding-left: 20px;
}

button {
    cursor: pointer;
    border: none;
    padding: 10px 20px;
    font-size: 1rem;
    font-weight: 600;
    border-radius: 4px;
    transition: background-color 0.2s, color 0.2s;
}

button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

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

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

.secondary-btn {
    background-color: var(--secondary-color);
    color: var(--text-main);
}

.secondary-btn:hover:not(:disabled) {
    background-color: var(--secondary-hover);
}

.danger-btn {
    background-color: var(--danger-color);
    color: white;
}

.danger-btn:hover:not(:disabled) {
    background-color: var(--danger-hover);
}

.quiz-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 1px solid var(--border-color);
    font-weight: 600;
    color: var(--text-muted);
}

.question-container {
    background-color: var(--bg-card);
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
    margin-bottom: 20px;
}

.question-text {
    font-size: 1.2rem;
    font-weight: 500;
    margin-bottom: 25px;
}

.option {
    display: block;
    width: 100%;
    text-align: left;
    background-color: white;
    border: 2px solid var(--border-color);
    padding: 15px;
    margin-bottom: 10px;
    border-radius: 6px;
    font-size: 1rem;
    color: var(--text-main);
    font-weight: normal;
}

.option:hover:not(:disabled) {
    border-color: var(--primary-color);
    background-color: #f8fafc;
}

.option.selected {
    background-color: var(--selected-bg);
    border-color: var(--selected-border);
}

/* Feedback classes for Drill mode */
.option.correct {
    background-color: var(--correct-bg);
    border-color: var(--correct-border);
    color: #166534;
}

.option.wrong {
    background-color: var(--wrong-bg);
    border-color: var(--wrong-border);
    color: #991b1b;
}

.drill-feedback {
    background-color: var(--bg-card);
    padding: 20px;
    border-radius: 8px;
    border-left: 4px solid var(--primary-color);
    margin-bottom: 20px;
}

.drill-feedback.hidden {
    display: none;
}

.drill-feedback.correct {
    border-left-color: #22c55e;
}

.drill-feedback.wrong {
    border-left-color: #ef4444;
}

#feedback-text {
    font-weight: bold;
    margin-bottom: 10px;
}

.quiz-controls {
    display: flex;
    justify-content: space-between;
    margin-top: 20px;
}

.card {
    background-color: var(--bg-card);
    padding: 25px;
    border-radius: 8px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
    margin-bottom: 20px;
}

.overall-result {
    text-align: center;
}

.overall-result h3 {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 10px;
}

.topic-results-container {
    display: grid;
    gap: 15px;
}

.topic-card {
    background-color: var(--bg-card);
    padding: 20px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
}

.topic-card.high-priority {
    border-left: 4px solid var(--danger-color);
}

.topic-card.low-priority {
    border-left: 4px solid #22c55e;
}

.topic-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
}

.topic-title {
    font-weight: bold;
    font-size: 1.1rem;
}

.topic-priority-badge {
    font-size: 0.8rem;
    padding: 4px 8px;
    border-radius: 12px;
    font-weight: 600;
}

.badge-high {
    background-color: var(--wrong-bg);
    color: #991b1b;
}

.badge-low {
    background-color: var(--correct-bg);
    color: #166534;
}

.topic-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    gap: 10px;
    font-size: 0.9rem;
}

.stat-box {
    background-color: var(--bg-main);
    padding: 10px;
    border-radius: 4px;
    text-align: center;
}

.stat-value {
    font-weight: bold;
    font-size: 1.1rem;
    color: var(--primary-color);
}

footer {
    text-align: center;
    padding: 30px 0;
    margin-top: 50px;
    color: var(--text-muted);
    font-size: 0.9rem;
    border-top: 1px solid var(--border-color);
}

@media (max-width: 600px) {
    .topic-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 10px;
    }
}

.drill-comparison {
    margin-top: 20px;
    padding-top: 20px;
    border-top: 1px solid var(--border-color);
    font-size: 1.1rem;
    color: var(--text-muted);
}

.drill-comparison div {
    margin-bottom: 5px;
}

.drill-comparison .change-positive {
    color: #166534;
    font-weight: bold;
}

.drill-comparison .change-negative {
    color: #991b1b;
    font-weight: bold;
}

.drill-comparison .change-neutral {
    color: var(--text-main);
    font-weight: bold;
}

.badges-container {
    display: flex;
    gap: 8px;
    align-items: center;
    flex-wrap: wrap;
}
.performance-badge {
    font-size: 0.8rem;
    padding: 4px 8px;
    border-radius: 12px;
    font-weight: 600;
}
.badge-good {
    background-color: var(--correct-bg, #dcfce7);
    color: #166534;
}
.badge-warn {
    background-color: #fef08a;
    color: #854d0e;
}
.badge-bad {
    background-color: var(--wrong-bg, #fee2e2);
    color: #991b1b;
}
.badge-neutral {
    background-color: #e5e7eb;
    color: #374151;
}
.transparency-note {
    font-size: 0.85rem;
    color: #6b7280;
    margin-bottom: 15px;
    text-align: center;
}

.explanation-card {
    background-color: var(--secondary-color, #e2e8f0);
    border-radius: 8px;
    padding: 15px;
    margin-top: 15px;
    font-size: 0.95rem;
    color: var(--text-main, #1e293b);
}
.diagnostic-review-container {
    display: flex;
    flex-direction: column;
    gap: 20px;
}
.review-item {
    background-color: var(--bg-card, #ffffff);
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}
.review-question {
    font-weight: 600;
    margin-bottom: 10px;
}
.review-answers {
    margin-bottom: 10px;
}
.review-correct {
    color: #166534;
    font-weight: bold;
}
.review-incorrect {
    color: #991b1b;
    font-weight: bold;
}
/* Progress Screen Styles */
.progress-summary {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
    margin-bottom: 30px;
}
.progress-stat-card {
    background: var(--bg-card);
    padding: 15px;
    border-radius: 8px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
    text-align: center;
}
.progress-stat-card h4 {
    margin-bottom: 5px;
    color: var(--text-muted);
    font-size: 0.9rem;
}
.progress-stat-card p {
    font-size: 1.2rem;
    font-weight: 700;
}
.progress-table-container {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    margin-bottom: 25px;
}
.progress-table {
    width: 100%;
    min-width: 500px; /* Force scroll on mobile rather than crushing */
    border-collapse: collapse;
    font-size: 0.9rem;
}
.progress-table th, .progress-table td {
    padding: 10px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}
.progress-table th {
    background-color: var(--secondary-color);
    font-weight: 600;
}

.question-text, .option, .explanation-card, p, h1, h2, h3, h4, .review-item, .mistake-item, .topic-title {
    word-break: break-word;
    overflow-wrap: break-word;
}

.score-circle {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background-color: var(--bg-card);
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
    margin: 20px 0;
}

.score-number {
    font-size: 2.5rem;
    font-weight: bold;
    color: var(--primary-color);
    margin-bottom: 10px;
}

.score-label {
    font-size: 1.2rem;
    color: var(--text-muted);
}

@media (max-width: 600px) {
    header {
        padding: 15px 0;
        margin-bottom: 20px;
    }
    
    header h1 {
        font-size: 1.5rem;
    }
    
    .question-container {
        padding: 15px;
    }
    
    .card, .review-item, .mistake-item {
        padding: 15px;
    }
    
    .question-text {
        font-size: 1.1rem;
        margin-bottom: 20px;
    }
    
    .option {
        padding: 12px 15px;
        font-size: 0.95rem;
    }
    
    button {
        padding: 12px 20px; /* Better touch target */
        width: 100%;
        margin-bottom: 10px;
    }
    
    .quiz-controls {
        flex-direction: column;
        gap: 10px;
    }
    
    .quiz-controls button {
        width: 100%;
        margin-bottom: 0;
    }
    
    .actions {
        display: flex;
        flex-direction: column;
        gap: 10px;
    }
    
    .actions button, .actions a.primary-btn, .actions a.secondary-btn {
        width: 100%;
        margin-bottom: 0;
        display: block;
        box-sizing: border-box;
    }
    
    .progress-summary {
        grid-template-columns: 1fr;
    }
    
    .topic-stats {
        grid-template-columns: 1fr 1fr;
    }
}

.topic-practice-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 10px;
    margin-top: 15px;
}

button:focus, a:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

.option:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 1px;
}

/* Modal Styles */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0,0,0,0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
}
.modal.hidden {
    display: none;
}
.modal-content {
    width: 90%;
    max-width: 400px;
}

/* Palette Styles */
.quiz-palette-container {
    background-color: var(--bg-card);
    padding: 15px;
    border-radius: 8px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
    margin-bottom: 20px;
}
.quiz-palette-container.hidden {
    display: none;
}
.quiz-palette {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}
.palette-btn {
    width: 36px;
    height: 36px;
    padding: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1px solid var(--border-color);
    background-color: var(--bg-main);
    color: var(--text-main);
    border-radius: 4px;
    font-weight: bold;
    font-size: 0.9rem;
    transition: all 0.2s;
}
.palette-btn:hover {
    border-color: var(--primary-color);
}
.palette-btn.answered {
    background-color: var(--correct-bg);
    border-color: var(--correct-border);
    color: #166534;
}
.palette-btn.current {
    border: 2px solid var(--primary-color);
    box-shadow: 0 0 0 2px rgba(15, 76, 129, 0.2);
}
.palette-btn.marked {
    background-color: #fef08a;
    border-color: #eab308;
    color: #854d0e;
}
/* Mobile adjustments */
@media (max-width: 600px) {
    .palette-btn {
        width: 40px;
        height: 40px;
        font-size: 0.95rem;
    }
    .quiz-controls > div {
        display: flex;
        width: 100%;
        gap: 10px;
    }
    .quiz-controls > div > button {
        flex: 1;
        margin: 0 !important;
    }
}