:root {
    --primary-color: #f59e0b;
    --primary-dark: #d97706;
    --primary-light: #fbbf24;
    --secondary-color: #374151;
    --secondary-light: #6b7280;
    --secondary-dark: #1f2937;
    --accent-color: #fcd34d;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
    --light-color: #f9fafb;
    --dark-color: #111827;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    background-color: var(--gray-100);
    color: var(--gray-800);
}

main {
    flex: 1;
}

.bg-gradient-primary {
    background: linear-gradient(135deg, var(--secondary-dark) 0%, var(--secondary-color) 50%, var(--gray-600) 100%);
}

.bg-primary {
    background-color: var(--primary-color) !important;
}

.bg-secondary-dark {
    background-color: var(--secondary-dark) !important;
}

.navbar {
    background-color: var(--secondary-dark) !important;
}

.btn-primary {
    background-color: var(--primary-color);
    border-color: var(--primary-color);
    color: var(--gray-900);
    font-weight: 600;
}

.btn-primary:hover {
    background-color: var(--primary-dark);
    border-color: var(--primary-dark);
    color: var(--gray-900);
}

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

.btn-outline-primary:hover,
.btn-outline-primary.active {
    background-color: var(--primary-color);
    border-color: var(--primary-color);
    color: var(--gray-900);
}

.btn-light {
    background-color: #ffffff;
    border-color: #ffffff;
    color: var(--secondary-dark);
    font-weight: 600;
}

.btn-light:hover {
    background-color: var(--gray-100);
    border-color: var(--gray-100);
    color: var(--secondary-dark);
}

.btn-outline-light {
    color: #ffffff;
    border-color: rgba(255, 255, 255, 0.5);
}

.btn-outline-light:hover {
    background-color: rgba(255, 255, 255, 0.1);
    border-color: #ffffff;
    color: #ffffff;
}

.text-primary {
    color: var(--primary-color) !important;
}

.text-yellow {
    color: var(--primary-color) !important;
}

.hero-section {
    min-height: 70vh;
    display: flex;
    align-items: center;
    position: relative;
    overflow: hidden;
}

.hero-image {
    max-width: 100%;
    height: auto;
    max-height: 250px;
    margin-bottom: 2rem;
    border-radius: 12px;
    opacity: 0.9;
}

.min-vh-50 {
    min-height: 50vh;
}

.feature-icon {
    width: 60px;
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark)) !important;
}

.card {
    transition: transform 0.2s ease-in-out, box-shadow 0.2s ease-in-out;
    border-radius: 12px;
}

.card:hover {
    transform: translateY(-2px);
}

.instruction-number {
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    flex-shrink: 0;
    background-color: var(--primary-color) !important;
    color: var(--gray-900) !important;
}

.answer-btn {
    padding: 1rem 1.5rem;
    font-size: 1.1rem;
    transition: all 0.2s ease;
    border-color: var(--gray-400);
    color: var(--gray-700);
}

.answer-btn:hover {
    transform: scale(1.02);
    border-color: var(--primary-color);
    background-color: rgba(245, 158, 11, 0.1);
    color: var(--gray-800);
}

.answer-btn.active,
.answer-btn.btn-primary {
    background-color: var(--primary-color) !important;
    border-color: var(--primary-color) !important;
    color: var(--gray-900) !important;
}

.confidence-btn {
    min-width: 80px;
    padding: 0.75rem 1.25rem;
    font-weight: 600;
    transition: all 0.2s ease;
    border-color: var(--gray-400);
    color: var(--gray-600);
}

.confidence-btn:hover {
    transform: scale(1.05);
    background-color: var(--primary-color);
    border-color: var(--primary-color);
    color: var(--gray-900);
}

.progress {
    border-radius: 10px;
    overflow: hidden;
    background-color: var(--gray-200);
}

.progress-bar {
    background: linear-gradient(90deg, var(--primary-color), var(--primary-dark));
    transition: width 0.3s ease;
}

.stat-row {
    transition: background-color 0.2s ease;
}

.stat-row:hover {
    background-color: rgba(245, 158, 11, 0.05);
}

.stats-container .stat-item {
    padding: 1rem;
}

.form-range::-webkit-slider-thumb {
    background: var(--primary-color);
}

.form-range::-moz-range-thumb {
    background: var(--primary-color);
}

.table th {
    font-weight: 600;
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    background-color: var(--gray-100);
}

.navbar-brand {
    font-size: 1.25rem;
}

.footer {
    background-color: var(--secondary-dark);
    color: var(--gray-300);
}

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

.footer a:hover {
    color: var(--primary-light);
    text-decoration: underline;
}

.footer-heading {
    color: #ffffff;
    font-weight: 600;
    margin-bottom: 1rem;
}

.footer-link {
    color: var(--gray-400);
    text-decoration: none;
    display: block;
    margin-bottom: 0.5rem;
    transition: color 0.2s ease;
}

.footer-link:hover {
    color: var(--primary-color);
}

.footer-bottom {
    border-top: 1px solid var(--gray-700);
    padding-top: 1.5rem;
    margin-top: 2rem;
}

@media (max-width: 768px) {
    .hero-section {
        min-height: auto;
        padding: 3rem 0;
    }
    
    .hero-image {
        max-height: 150px;
    }
    
    .display-4 {
        font-size: 1rem;
    }
    
    .confidence-btn {
        min-width: 60px;
        padding: 0.5rem 0.75rem;
    }
    
    .stats-container {
        flex-direction: column;
    }
    
    .stats-container .stat-item {
        margin-bottom: 1rem;
    }
}

.badge {
    font-weight: 500;
}

.badge.bg-secondary {
    background-color: var(--gray-600) !important;
}

.badge.bg-primary {
    background-color: var(--primary-color) !important;
    color: var(--gray-900);
}

.badge.bg-info {
    background-color: var(--primary-light) !important;
    color: var(--gray-900);
}

.alert {
    border: none;
    border-radius: 10px;
}

.alert-info {
    background-color: rgba(245, 158, 11, 0.1);
    color: var(--gray-800);
    border-left: 4px solid var(--primary-color);
}

.alert-warning {
    background-color: rgba(245, 158, 11, 0.15);
    color: var(--gray-800);
    border-left: 4px solid var(--primary-dark);
}

.card-header.bg-primary {
    background-color: var(--secondary-dark) !important;
}

.table-success {
    background-color: rgba(16, 185, 129, 0.1) !important;
}

.table-danger {
    background-color: rgba(239, 68, 68, 0.1) !important;
}

.bg-success {
    background-color: var(--success-color) !important;
}

.bg-danger {
    background-color: var(--danger-color) !important;
}

.bg-warning {
    background-color: var(--primary-color) !important;
    color: var(--gray-900) !important;
}

.text-warning {
    color: var(--primary-color) !important;
}

/* --- Calibration chart --- */
.calibration-chart .chart-wrap {
    background: #ffffff;
    border: 1px solid var(--gray-200);
    border-radius: 12px;
    padding: 12px;
    box-shadow: 0 1px 2px rgba(0,0,0,0.04);
}

.calibration-svg {
    width: 100%;
    height: 340px;
    display: block;
}

.cal-bg {
    fill: #ffffff;
}

.cal-grid {
    stroke: var(--gray-200);
    stroke-width: 1;
}

.cal-axis {
    stroke: var(--gray-700);
    stroke-width: 2;
}

.cal-tick {
    stroke: var(--gray-700);
    stroke-width: 2;
}

.cal-label {
    fill: var(--gray-600);
    font-size: 12px;
    font-weight: 500;
}

.cal-axis-title {
    fill: var(--gray-800);
    font-size: 14px;
    font-weight: 700;
}

.cal-refline {
    fill: none;
    stroke: var(--gray-500);
    stroke-width: 2.5;
    stroke-dasharray: 6 6;
    opacity: 0.9;
}

/* Match your badge logic visually */
.cal-point {
    stroke: #ffffff;
    stroke-width: 2;
}

.cal-point-good {
    fill: var(--success-color);
}

.cal-point-over {
    fill: var(--danger-color);
}

.cal-point-under {
    fill: var(--warning-color);
}

.cal-point-label {
    fill: var(--gray-700);
    font-size: 12px;
    font-weight: 600;
}

@media (max-width: 768px) {
    .calibration-svg {
        height: 300px;
    }
    .cal-point-label {
        font-size: 11px;
    }
}