/* ============================================
   JAMB Quiz App - Enhanced Styles (FIXED)
   ============================================ */

:root {
    --primary-color: #1a472a;
    --secondary-color: #2d5f3f;
    --accent-color: #4ade80;
    --success-color: #22c55e;
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
    --info-color: #3b82f6;
    --purple-primary: #667eea;
    --purple-secondary: #764ba2;
    --whatsapp-color: #25D366;
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.15);
    --transition-base: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

/* ============================================
   Screen Management
   ============================================ */

.screen {
    display: none;
    min-height: 100vh;
    animation: fadeIn 0.3s ease;
}

.screen.active {
    display: block;
}

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

/* ============================================
   ✅ ENHANCED BUTTONS
   ============================================ */

.btn {
    padding: 14px 28px;
    border: none;
    border-radius: 10px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition-base);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    position: relative;
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.btn:active {
    transform: scale(0.98);
}

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

/* Primary Button */
.btn-primary {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    box-shadow: 0 4px 15px rgba(26, 71, 42, 0.3);
}

.btn-primary:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(26, 71, 42, 0.4);
}

.btn-primary::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
    transition: left 0.5s;
}

.btn-primary:hover::before {
    left: 100%;
}

/* Secondary Button (Purple for Single Subject) */
.btn-secondary {
    background: linear-gradient(135deg, var(--purple-primary) 0%, var(--purple-secondary) 100%);
    color: white;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.3);
}

.btn-secondary:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(102, 126, 234, 0.4);
}

/* Success Button */
.btn-success {
    background: linear-gradient(135deg, var(--success-color) 0%, #16a34a 100%);
    color: white;
    box-shadow: 0 4px 15px rgba(34, 197, 94, 0.3);
}

.btn-success:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(34, 197, 94, 0.4);
}

/* WhatsApp Button */
.btn-whatsapp {
    background: linear-gradient(135deg, var(--whatsapp-color) 0%, #128C7E 100%);
    color: white;
    padding: 12px 24px;
    border-radius: 10px;
    font-weight: 600;
    box-shadow: 0 4px 15px rgba(37, 211, 102, 0.3);
    transition: var(--transition-base);
}

.btn-whatsapp:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(37, 211, 102, 0.4);
}

/* Large Button */
.btn-large {
    padding: 18px 36px;
    font-size: 18px;
    width: 100%;
    max-width: 400px;
    margin: 20px auto;
    display: flex;
    border-radius: 12px;
}

/* Back Button */
.btn-back {
    background: transparent;
    border: none;
    font-size: 16px;
    color: var(--primary-color);
    cursor: pointer;
    padding: 8px 16px;
    font-weight: 600;
    transition: var(--transition-base);
}

.btn-back:hover {
    transform: translateX(-3px);
}

/* ============================================
   Home Screen
   ============================================ */

.app-header {
    text-align: center;
    padding: 40px 20px;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    border-radius: 16px;
    margin-bottom: 40px;
    position: relative;
    box-shadow: var(--shadow-lg);
}

.logo h1 {
    font-size: 2.5rem;
    margin-bottom: 8px;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.2);
}

.logo p {
    font-size: 1.2rem;
    opacity: 0.9;
}

.install-btn {
    position: absolute;
    top: 20px;
    right: 20px;
    background: rgba(255, 255, 255, 0.2);
    color: white;
    border: 2px solid white;
    padding: 8px 16px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 14px;
    transition: var(--transition-base);
}

.install-btn:hover {
    background: rgba(255, 255, 255, 0.3);
}

.mode-selection h2 {
    text-align: center;
    margin-bottom: 30px;
    color: var(--text-primary);
    font-size: 2rem;
}

.mode-selection h3 {
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 8px;
    margin-bottom: 16px;
}

.mode-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 24px;
    margin-bottom: 40px;
}

.mode-card {
    background: var(--card-bg);
    padding: 32px;
    border-radius: 16px;
    text-align: center;
    box-shadow: var(--shadow-md);
    transition: var(--transition-base);
    border: 2px solid transparent;
}

.mode-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

/* Highlight single subject cards */
.mode-card.single-subject-card {
    border-color: rgba(102, 126, 234, 0.2);
    background: linear-gradient(135deg, rgba(102, 126, 234, 0.03), rgba(118, 75, 162, 0.03));
}

.mode-icon {
    font-size: 3rem;
    margin-bottom: 16px;
}

.mode-card h3 {
    font-size: 1.5rem;
    margin-bottom: 12px;
    border-bottom: none;
}

.mode-card p {
    color: var(--text-secondary);
    margin-bottom: 8px;
}

.mode-detail {
    font-size: 0.9rem;
    margin-bottom: 20px !important;
    color: var(--info-color);
    font-weight: 600;
}

/* ============================================
   Statistics
   ============================================ */

.stats-section {
    margin-top: 40px;
}

.stats-section h3 {
    text-align: center;
    margin-bottom: 24px;
    font-size: 1.5rem;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
}

.stat-card {
    background: var(--card-bg);
    padding: 24px;
    border-radius: 12px;
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: var(--transition-base);
}

.stat-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
}

.stat-value {
    font-size: 2rem;
    font-weight: bold;
    color: var(--primary-color);
    margin-bottom: 8px;
}

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

/* ============================================
   Subject Selection
   ============================================ */

.screen-header {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-bottom: 30px;
}

.screen-header h2 {
    flex: 1;
    text-align: center;
}

.subject-note {
    background: linear-gradient(135deg, #fef3c7, #fde68a);
    padding: 20px;
    border-radius: 12px;
    margin-bottom: 30px;
    text-align: center;
    box-shadow: var(--shadow-sm);
}

.subject-note strong {
    color: var(--primary-color);
}

.mode-info {
    margin-top: 8px;
    font-size: 0.95rem;
    color: var(--text-secondary);
    font-weight: 600;
}

.subjects-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
    padding: 0 8px;
    margin: 20px 0;
}

.subject-card {
    padding: 12px 8px;
    text-align: center;
    font-size: 0.95rem;
    background: var(--card-bg);
    border-radius: 12px;
    box-shadow: var(--shadow-sm);
    transition: var(--transition-base);
    cursor: pointer;
    border: 2px solid transparent;
}

.subject-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
}

.subject-card.selected {
    border: 2px solid var(--primary-color);
    background: linear-gradient(135deg, rgba(26, 71, 42, 0.08), rgba(45, 95, 63, 0.08));
}

.subject-card.compulsory {
    border: 2px solid var(--accent-color);
    background: linear-gradient(135deg, rgba(74, 222, 128, 0.15), rgba(34, 197, 94, 0.15));
}

.subject-icon {
    font-size: 2.5rem;
    margin-bottom: 12px;
}

.subject-card h3 {
    font-size: 1.1rem;
    margin: 8px 0 12px;
}

.compulsory-badge {
    background: var(--accent-color);
    color: var(--primary-color);
    padding: 4px 12px;
    border-radius: 12px;
    font-size: 0.8rem;
    font-weight: bold;
    display: inline-block;
    margin-top: 8px;
}

.subject-checkbox {
    width: 20px;
    height: 20px;
    cursor: pointer;
    margin-top: 8px;
}

.selection-info {
    text-align: center;
    font-size: 1.3rem;
    margin: 20px 0;
    color: var(--text-primary);
    font-weight: 700;
}

/* ============================================
   Quiz Screen
   ============================================ */

.quiz-header {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    padding: 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-md);
}

.quiz-info {
    display: flex;
    gap: 24px;
    align-items: center;
}

.timer {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 1.2rem;
    font-weight: bold;
}

.progress-info {
    font-size: 1.1rem;
}

.subject-indicator {
    background: rgba(255, 255, 255, 0.2);
    padding: 8px 16px;
    border-radius: 8px;
    font-weight: 600;
}

.quiz-container {
    max-width: 900px;
    margin: 0 auto;
    padding: 20px;
}

.progress-bar {
    width: 100%;
    height: 8px;
    background: var(--border-color);
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 30px;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
    transition: width 0.3s ease;
}

.question-section {
    background: var(--card-bg);
    padding: 32px;
    border-radius: 16px;
    box-shadow: var(--shadow-md);
    margin-bottom: 30px;
}

.question-number {
    color: var(--primary-color);
    font-weight: bold;
    font-size: 0.9rem;
    margin-bottom: 16px;
}

.question-text {
    font-size: 1.2rem;
    line-height: 1.8;
    margin-bottom: 24px;
    color: var(--text-primary);
}

.options-container {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.option {
    background: var(--bg-color);
    padding: 16px 20px;
    border-radius: 12px;
    border: 2px solid var(--border-color);
    cursor: pointer;
    transition: var(--transition-base);
    display: flex;
    align-items: center;
    gap: 12px;
}

.option:hover {
    background: white;
    border-color: var(--primary-color);
    transform: translateX(5px);
}

.option.selected {
    background: linear-gradient(135deg, rgba(26, 71, 42, 0.1), rgba(45, 95, 63, 0.1));
    border-color: var(--primary-color);
    font-weight: 600;
}

.option-label {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: var(--border-color);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    flex-shrink: 0;
    transition: var(--transition-base);
}

.option.selected .option-label {
    background: var(--primary-color);
    color: white;
}

.quiz-navigation {
    display: flex;
    gap: 16px;
    justify-content: space-between;
    margin-bottom: 30px;
}

.quiz-navigation .btn {
    flex: 1;
}

/* Passage Box */
.passage-box {
    background: linear-gradient(135deg, #f8f9fa, #e9ecef);
    border-left: 4px solid var(--primary-color);
    padding: 20px;
    margin: 20px 0;
    border-radius: 0 12px 12px 0;
    font-family: Georgia, 'Times New Roman', serif;
    font-size: 16px;
    line-height: 1.8;
    color: #333;
    box-shadow: var(--shadow-sm);
}

.passage-box h3 {
    margin-top: 0;
    color: var(--primary-color);
    font-size: 18px;
    margin-bottom: 12px;
}

/* ============================================
   Question Navigator
   ============================================ */

.question-navigator {
    background: var(--card-bg);
    padding: 24px;
    border-radius: 16px;
    box-shadow: var(--shadow-md);
}

.btn-toggle-nav {
    width: 100%;
    padding: 12px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 600;
    margin-bottom: 16px;
    transition: var(--transition-base);
}

.btn-toggle-nav:hover {
    background: var(--secondary-color);
}

#navGrid {
    display: grid;
    grid-template-columns: repeat(10, 1fr);
    gap: 8px;
    max-height: 320px;
    overflow-y: auto;
    padding: 12px 8px;
    background: #f9fbfa;
    border-radius: 8px;
    scrollbar-width: thin;
    scrollbar-color: #ccc #f9fbfa;
}

#navGrid::-webkit-scrollbar {
    width: 6px;
}

#navGrid::-webkit-scrollbar-thumb {
    background-color: #ccc;
    border-radius: 3px;
}

.nav-item {
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 14px;
    border-radius: 6px;
    background: #fff;
    border: 1px solid #ddd;
    cursor: pointer;
    user-select: none;
    box-shadow: var(--shadow-sm);
    transition: var(--transition-base);
}

.nav-item:hover {
    transform: scale(1.1);
    box-shadow: var(--shadow-md);
}

.nav-item.current {
    background: var(--primary-color);
    color: white;
    border: 2px solid #0d3b21;
    font-weight: bold;
}

.nav-item.answered {
    background: #e8f5e9;
    border-color: #c8e6c9;
}

.nav-subject-header {
    grid-column: span 10;
    text-align: left;
    margin-top: 12px;
    font-weight: bold;
    color: var(--primary-color);
    font-size: 14px;
}

/* ============================================
   Results & Review
   ============================================ */

.results-container {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.results-header {
    margin-bottom: 40px;
}

.results-icon {
    font-size: 4rem;
    margin-bottom: 16px;
    animation: bounce 1s ease-in-out;
}

@keyframes bounce {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-20px); }
}

.score-display {
    display: flex;
    justify-content: center;
    margin-bottom: 40px;
}

.score-circle {
    position: relative;
    width: 200px;
    height: 200px;
}

.score-bg {
    fill: none;
    stroke: var(--border-color);
    stroke-width: 10;
}

.score-progress {
    fill: none;
    stroke: var(--accent-color);
    stroke-width: 10;
    stroke-linecap: round;
    transform: rotate(-90deg);
    transform-origin: center;
    stroke-dasharray: 565;
    stroke-dashoffset: 565;
    transition: stroke-dashoffset 1s ease;
}

.score-text {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

.score-percentage {
    font-size: 2.5rem;
    font-weight: bold;
    color: var(--primary-color);
}

.results-summary {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 20px;
    margin-bottom: 40px;
}

.summary-card {
    background: var(--card-bg);
    padding: 24px;
    border-radius: 12px;
    box-shadow: var(--shadow-md);
    transition: var(--transition-base);
}

.summary-card:hover {
    transform: translateY(-5px);
}

.summary-icon {
    font-size: 2rem;
    margin-bottom: 12px;
}

.summary-value {
    font-size: 2rem;
    font-weight: bold;
    margin-bottom: 8px;
}

.summary-card.correct .summary-value {
    color: var(--success-color);
}

.summary-card.wrong .summary-value {
    color: var(--danger-color);
}

.summary-card.unanswered .summary-value {
    color: var(--warning-color);
}

.subject-breakdown {
    background: var(--card-bg);
    padding: 24px;
    border-radius: 12px;
    box-shadow: var(--shadow-md);
    margin-bottom: 30px;
}

.subject-result {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 0;
    border-bottom: 1px solid var(--border-color);
}

.subject-result:last-child {
    border-bottom: none;
}

.subject-result-score {
    color: var(--primary-color);
    font-weight: bold;
}

.results-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
    justify-content: center;
}

.review-filters {
    display: flex;
    gap: 12px;
    margin-bottom: 30px;
    flex-wrap: wrap;
    justify-content: center;
}

.filter-btn {
    padding: 10px 20px;
    border: 2px solid var(--border-color);
    background: white;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 600;
    transition: var(--transition-base);
}

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

.review-item {
    background: var(--card-bg);
    padding: 24px;
    border-radius: 12px;
    margin-bottom: 20px;
    box-shadow: var(--shadow-md);
}

.review-item.hidden {
    display: none;
}

.review-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 16px;
}

.review-question-number {
    font-weight: bold;
    color: var(--primary-color);
}

.review-status {
    padding: 6px 12px;
    border-radius: 6px;
    font-size: 0.9rem;
    font-weight: 600;
}

.review-status.correct {
    background: rgba(34, 197, 94, 0.1);
    color: var(--success-color);
}

.review-status.wrong {
    background: rgba(239, 68, 68, 0.1);
    color: var(--danger-color);
}

.review-status.unanswered {
    background: rgba(245, 158, 11, 0.1);
    color: var(--warning-color);
}

.review-question {
    font-size: 1.1rem;
    margin-bottom: 16px;
    line-height: 1.6;
}

.review-option {
    padding: 12px 16px;
    margin: 8px 0;
    border-radius: 8px;
    background: var(--bg-color);
}

.review-option.user-answer {
    background: rgba(239, 68, 68, 0.1);
    border: 2px solid var(--danger-color);
}

.review-option.user-answer.correct-answer {
    background: rgba(34, 197, 94, 0.1);
    border: 2px solid var(--success-color);
}

/* ============================================
   Responsive Design
   ============================================ */

@media (max-width: 768px) {
    .subjects-grid {
        grid-template-columns: repeat(3, 1fr);
    }

    .logo h1 {
        font-size: 2rem;
    }

    .mode-cards {
        grid-template-columns: 1fr;
    }

    .quiz-header {
        flex-direction: column;
        gap: 12px;
    }

    .quiz-info {
        width: 100%;
        justify-content: space-between;
    }

    .quiz-navigation {
        flex-direction: column;
    }

    .results-actions {
        flex-direction: column;
    }

    .results-actions .btn {
        width: 100%;
    }

    .install-btn {
        position: static;
        margin-top: 16px;
        width: 100%;
    }
}

@media (max-width: 360px) {
    .subjects-grid {
        grid-template-columns: repeat(2, 1fr);
    }
   }