:root {
    --primary-color: #4a6fa5;
    --primary-light: #6a8cc9;
    --primary-dark: #345284;
    --accent-color: #ff9800;
    --accent-light: #ffb74d;
    --accent-dark: #f57c00;
    --text-dark: #333;
    --text-light: #f8f9fa;
    --bg-light: #f8f9fa;
    --bg-dark: #212529;
    --gray-100: #f8f9fa;
    --gray-200: #e9ecef;
    --gray-300: #dee2e6;
    --gray-400: #ced4da;
    --gray-500: #adb5bd;
    --gray-600: #6c757d;
    --gray-700: #495057;
    --gray-800: #343a40;
    --gray-900: #212529;
    --border-radius: 8px;
    --box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

body {
    font-family: 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', sans-serif;
    color: var(--text-dark);
    line-height: 1.6;
    background-color: var(--bg-light);
}

/* === Page Header === */
.page-header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: white;
    padding: 3rem 0;
    margin-bottom: 2rem;
    text-align: left; /* Changed from center to left */
}
.page-header h1 {
    color: white;
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
    text-align: left; /* Ensure left alignment */
}
.page-header p {
    font-size: 1.1rem;
    opacity: 0.9;
    max-width: 800px; /* Increased from 600px */
    text-align: left; /* Ensure left alignment */
}

/* === Main Content Styles === */
.test-card {
    background-color: white;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    margin-bottom: 1.5rem;
    overflow: hidden;
    transition: var(--transition);
}

.test-card:hover {
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.test-card-header {
    background-color: var(--primary-color);
    color: white;
    padding: 1rem 1.5rem;
}

.test-card-body {
    padding: 1.5rem;
}

.form-group {
    margin-bottom: 1.25rem;
}

.input-with-tooltip {
    display: flex;
    align-items: center;
}

.info-tooltip {
    margin-left: 0.5rem;
    color: var(--gray-600);
    cursor: pointer;
    font-size: 0.875rem;
}

.info-tooltip:hover {
    color: var(--primary-color);
}

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

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

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

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

.result-section {
    background-color: var(--gray-100);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    margin-top: 1.5rem;
}

.chart-container {
    position: relative;
    height: 300px;
    margin: 1.5rem 0;
}

.steps-container {
    counter-reset: steps;
}

.step-item {
    position: relative;
    padding-left: 2.5rem;
    margin-bottom: 1.25rem;
    counter-increment: steps;
}

.step-item::before {
    content: counter(steps);
    position: absolute;
    left: 0;
    top: 0;
    width: 1.75rem;
    height: 1.75rem;
    background-color: var(--primary-color);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.875rem;
    font-weight: bold;
}

.step-item h5 {
    margin-bottom: 0.5rem;
    color: var(--primary-dark);
}

.simulation-container {
    background-color: white;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    padding: 1.5rem;
    margin-top: 2rem;
}

.math-formula {
    overflow-x: auto;
    margin: 1rem 0;
    padding: 0.75rem;
    background-color: var(--gray-100);
    border-radius: var(--border-radius);
}

.contingency-table {
    width: 100%;
    margin-bottom: 1rem;
}

.contingency-table td input {
    width: 100%;
}

.contingency-table th {
    background-color: var(--gray-200);
    padding: 0.5rem;
    text-align: center;
}

.contingency-table td {
    padding: 0.25rem;
}

.highlight {
    background-color: rgba(255, 152, 0, 0.15);
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
}

.learning-links {
    margin-top: 1.5rem;
    padding: 1rem;
    background-color: var(--gray-100);
    border-radius: var(--border-radius);
}

.learning-links h5 {
    margin-bottom: 0.75rem;
    color: var(--primary-color);
}

.learning-links ul {
    padding-left: 1.25rem;
}

.learning-links li {
    margin-bottom: 0.5rem;
}

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

.learning-links a:hover {
    text-decoration: underline;
}

/* Toggle control for simulation */
.simulation-toggle {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
    background-color: var(--primary-light);
    color: white;
    border-radius: var(--border-radius);
    margin-bottom: 1rem;
    cursor: pointer;
}

.toggle-icon {
    transition: transform 0.3s ease;
}

.toggle-open .toggle-icon {
    transform: rotate(180deg);
}

.simulation-content {
    display: none;
    padding: 1rem;
    background-color: white;
    border: 1px solid var(--gray-300);
    border-radius: 0 0 var(--border-radius) var(--border-radius);
}

.toggle-open + .simulation-content {
    display: block;
}