:root {
            --primary-color: #2c7da0;
            --secondary-color: #a9d6e5;
            --accent-color: #01497c;
            --stats-color: #e83e8c;
            --prob-color: #28a745;
            --zscore-color: #6f42c1;
            --light-gray: #f8f9fa;
            --border-color: #eaeaea;
            --text-color: #333;
            --text-muted: #6c757d;
        }
       .page-header {
            background: linear-gradient(135deg, rgba(169, 214, 229, 0.4) 0%, rgba(44, 125, 160, 0.4) 100%);
            padding: 1.5rem 0;
            margin-bottom: 2rem;
            border-bottom: 1px solid rgba(44, 125, 160, 0.2);
            position: relative;
            overflow: hidden;     color: var(--text-color);
        }
        .breadcrumb {
            background-color: transparent;
            padding: 0.5rem 0;
            margin-bottom: 0.5rem;
        }
        .breadcrumb-item a {
            color: var(--text-muted);
            text-decoration: none;
        }
        .breadcrumb-item.active {
            color: var(--text-color);
        }
        .form-control:focus {
            border-color: var(--primary-color);
            box-shadow: 0 0 0 3px rgba(44, 125, 160, 0.15);
        }
        .math-result {
            padding: 12px;
            background-color: white;
            border-radius: 4px;
            border: 1px solid #eee;
            font-size: 1.1rem;
            font-family: 'Cambria Math', 'Latin Modern Math', STIXGeneral, serif;
            margin: 10px 0;
            text-align: center;
        }
        .distribution-formula {
            font-size: 1.2rem;
            padding: 15px;
            background-color: rgba(44, 125, 160, 0.05);
            border-left: 4px solid var(--primary-color);
            border-radius: 4px;
            margin: 15px 0;
            text-align: center;
        }
        .stats-box {
            background-color: rgba(232, 62, 140, 0.05);
            border-left: 3px solid var(--stats-color);
            padding: 1rem;
            border-radius: 0 4px 4px 0;
            margin: 1.5rem 0;
        }
        @media (max-width: 768px) {
            }
        .calculation-step {
            margin-bottom: 1.5rem;
            padding-bottom: 1.5rem;
            border-bottom: 1px dashed var(--border-color);
        }
        .probability-result {
            padding: 1rem;
            background-color: rgba(40, 167, 69, 0.1);
            border-radius: 6px;
            margin: 1rem 0;
            border: 1px solid rgba(40, 167, 69, 0.2);
        }
        .probability-value {
            font-size: 1.8rem;
            font-weight: 700;
            color: var(--prob-color);
            text-align: center;
            margin: 0.5rem 0;
        }
        .probability-label {
            font-weight: 600;
            margin-bottom: 0.5rem;
            color: var(--text-color);
        }
        .zscore-table {
            width: 100%;
            border-collapse: collapse;
            margin: 1.5rem 0;
        }
        .zscore-table th, .zscore-table td {
            padding: 0.75rem;
            text-align: center;
            border: 1px solid var(--border-color);
        }
        .zscore-table th {
            background-color: var(--light-gray);
            font-weight: 600;
        }
        .zscore-table tr:nth-child(even) {
            background-color: rgba(111, 66, 193, 0.05);
        }
        .parameter-display {
            display: flex;
            align-items: center;
            margin: 1rem 0;
            padding: 1rem;
            background-color: rgba(255,255,255,0.8);
            border-radius: 6px;
            border: 1px solid var(--border-color);
        }
        .parameter-value {
            font-family: 'Courier New', monospace;
            background-color: rgba(44, 125, 160, 0.1);
            padding: 0.5rem;
            border-radius: 4px;
            margin: 0 0.5rem;
        }
        .parameter-label {
            font-weight: 600;
            margin-right: 0.5rem;
        }
        .graph-legend {
            display: flex;
            justify-content: center;
            flex-wrap: wrap;
            gap: 1.5rem;
            margin-top: 1rem;
        }
        .legend-item {
            display: flex;
            align-items: center;
        }
        .legend-color {
            width: 20px;
            height: 4px;
            margin-right: 0.5rem;
        }
        .distribution-color {
            background-color: rgba(44, 125, 160, 0.8);
        }
        .probability-color {
            background-color: rgba(40, 167, 69, 0.8);
        }
        .mean-color {
            width: 10px;
            height: 10px;
            border-radius: 50%;
            margin-right: 0.5rem;
            background-color: rgba(232, 62, 140, 0.8);
        }
        .range-selector {
            background-color: white;
            border-radius: 6px;
            padding: 1rem;
            border: 1px solid var(--border-color);
            margin: 1rem 0;
        }
        .range-option {
            display: inline-block;
            margin-right: 1rem;
            margin-bottom: 0.5rem;
        }
        .range-option input {
            margin-right: 0.5rem;
        }
        .interval-display {
            padding: 1rem;
            background-color: rgba(111, 66, 193, 0.1);
            border-radius: 6px;
            margin: 1rem 0;
            border: 1px solid rgba(111, 66, 193, 0.2);
        }
        .interval-value {
            font-size: 1.5rem;
            font-weight: 700;
            color: var(--zscore-color);
            text-align: center;
            margin: 0.5rem 0;
        }
        .dataset-container {
            margin-top: 2rem;
            padding-top: 1.5rem;
            border-top: 1px solid var(--border-color);
        }
        .dataset-controls {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 1rem;
            flex-wrap: wrap;
            gap: 1rem;
        }
        .dataset-buttons {
            display: flex;
            gap: 0.5rem;
        }
        .dataset-table-container {
            max-height: 400px;
            overflow-y: auto;
            border: 1px solid var(--border-color);
            border-radius: 6px;
            margin-bottom: 1rem;
            background-color: white;
        }
        .dataset-table {
            width: 100%;
            border-collapse: collapse;
        }
        .dataset-table th, .dataset-table td {
            padding: 0.75rem;
            text-align: center;
            border-bottom: 1px solid var(--border-color);
        }
        .dataset-table th {
            background-color: var(--light-gray);
            font-weight: 600;
            position: sticky;
            top: 0;
            z-index: 10;
        }
        .dataset-table tr:hover {
            background-color: rgba(44, 125, 160, 0.05);
        }
        .data-point {
            font-family: 'Courier New', monospace;
        }
        .dataset-info {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-top: 1rem;
            padding: 0.75rem;
            background-color: rgba(44, 125, 160, 0.05);
            border-radius: 6px;
            font-size: 0.9rem;
        }
        .dataset-summary {
            display: flex;
            gap: 1.5rem;
            flex-wrap: wrap;
        }
        .dataset-summary-item {
            display: flex;
            flex-direction: column;
        }
        .dataset-summary-label {
            font-weight: 600;
            color: var(--text-muted);
            font-size: 0.8rem;
        }
        .dataset-summary-value {
            font-weight: 700;
            color: var(--primary-color);
        }
        .dataset-tabs {
            margin-top: 1.5rem;
        }
        .dataset-tabs .dataset-tabs .dataset-raw {
            background-color: white;
            border: 1px solid var(--border-color);
            border-radius: 6px;
            padding: 1rem;
            max-height: 300px;
            overflow-y: auto;
            font-family: 'Courier New', monospace;
            font-size: 0.9rem;
            white-space: pre-wrap;
        }
        .mode-selector {
            margin-bottom: 1.5rem;
            padding: 1rem;
            background-color: rgba(44, 125, 160, 0.05);
            border-radius: 6px;
            border: 1px solid rgba(44, 125, 160, 0.2);
        }
        .mode-label {
            font-weight: 600;
            margin-bottom: 0.5rem;
            color: var(--primary-color);
        }
        .mode-description {
            font-size: 0.9rem;
            color: var(--text-muted);
            margin-bottom: 0.5rem;
        }
        .mode-buttons {
            display: flex;
            flex-wrap: wrap;
            gap: 0.5rem;
        }
        .mode-btn {
            flex: 1;
            min-width: 150px;
            padding: 0.75rem;
            border: 2px solid var(--border-color);
            border-radius: 6px;
            background-color: white;
            text-align: center;
            cursor: pointer;
            transition: all 0.3s;
        }
        .mode-btn:hover {
            border-color: var(--primary-color);
            background-color: rgba(44, 125, 160, 0.05);
        }
        .mode-btn.active {
            border-color: var(--primary-color);
            background-color: rgba(44, 125, 160, 0.1);
            color: var(--primary-color);
            font-weight: 600;
        }
        .mode-btn-icon {
            font-size: 1.5rem;
            margin-bottom: 0.5rem;
            display: block;
        }
        .preset-ranges {
            margin-top: 1rem;
            padding: 1rem;
            background-color: rgba(111, 66, 193, 0.05);
            border-radius: 6px;
            border: 1px solid rgba(111, 66, 193, 0.2);
        }
        .preset-title {
            font-weight: 600;
            margin-bottom: 0.5rem;
            color: var(--zscore-color);
        }
        .preset-buttons {
            display: flex;
            flex-wrap: wrap;
            gap: 0.5rem;
        }
        .preset-btn {
            padding: 0.5rem 0.75rem;
            border: 1px solid rgba(111, 66, 193, 0.3);
            border-radius: 4px;
            background-color: white;
            font-size: 0.9rem;
            cursor: pointer;
            transition: all 0.3s;
        }
        .preset-btn:hover {
            background-color: rgba(111, 66, 193, 0.1);
        }
        .advanced-section {
            animation: fadeIn 0.5s ease-in-out;
        }
        @keyframes fadeIn {
            from { opacity: 0; transform: translateY(-10px); }
            to { opacity: 1; transform: translateY(0); }
        }
        .basic-mode-info {
            padding: 1rem;
            background-color: rgba(44, 125, 160, 0.05);
            border-radius: 6px;
            border-left: 4px solid var(--primary-color);
            margin: 1rem 0;
        }
        .advanced-mode-info {
            padding: 1rem;
            background-color: rgba(40, 167, 69, 0.05);
            border-radius: 6px;
            border-left: 4px solid var(--prob-color);
            margin: 1rem 0;
        }