:root {
            --primary-color: #2c7da0;
            --secondary-color: #a9d6e5;
            --accent-color: #01497c;
            --hydration-blue: #1a8cff;
            --hydration-light-blue: #80d0ff;
            --sport-green: #28a745;
            --warning-orange: #fd7e14;
            --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);
        }
         
        
        /* Hydration Plan Grid */
        .hydration-plan-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
            gap: 1rem;
            margin: 1.5rem 0;
        }
        
        .hydration-phase-card {
            background: white;
            border-radius: 8px;
            padding: 1.25rem;
            border: 1px solid var(--border-color);
            box-shadow: 0 2px 4px rgba(0,0,0,0.05);
            text-align: center;
        }
        
        .hydration-phase-card.active {
            border: 2px solid var(--hydration-blue);
            background-color: rgba(26, 140, 255, 0.05);
        }
        
        .phase-name {
            font-weight: 600;
            margin-bottom: 0.5rem;
            color: var(--text-color);
        }
        
        .phase-value {
            font-size: 1.25rem;
            font-weight: 700;
            color: var(--hydration-blue);
        }
        
        .phase-desc {
            font-size: 0.85rem;
            color: var(--text-muted);
            margin-top: 0.5rem;
        }
         
        
        /* Responsive Adjustments */
        @media (max-width: 768px) {
 
            .hydration-plan-grid {
                grid-template-columns: 1fr;
            } 
            .timeline::before {
                left: 20px !important;
            }
            
            .timeline-item {
                flex-direction: row !important;
            }
            
            .timeline-content {
                width: calc(100% - 60px) !important;
                margin-left: 60px !important;
            }
            
            .timeline-marker {
                left: 20px !important;
            }
            
            .mobile-hidden {
                display: none !important;
            }
            
            .mobile-full-width {
                width: 100% !important;
            }
        }
        
        /* Measurement System Toggle */
        .measurement-system {
            display: flex;
            background-color: var(--light-gray);
            border-radius: 6px;
            padding: 4px;
            margin-bottom: 1.5rem;
        }
        
        .system-btn {
            flex: 1;
            text-align: center;
            padding: 0.75rem;
            border-radius: 4px;
            cursor: pointer;
            transition: all 0.3s;
            font-weight: 600;
        }
        
        .system-btn.active {
            background-color: var(--hydration-blue);
            color: white;
        }
        
        /* Toast notifications */
        .toast-container {
            position: fixed;
            bottom: 20px;
            right: 20px;
            z-index: 1050;
        }
        
        /* Action buttons */
        .action-btn {
            background-color: white;
            border: 1px solid var(--border-color);
            border-radius: 6px;
            padding: 0.5rem 1rem;
            margin-left: 0.5rem;
            transition: all 0.3s;
            color: var(--text-color);
        }
        
        .action-btn:hover {
            background-color: var(--light-gray);
            color: var(--primary-color);
        }
        
        /* Input group styling */
        .input-group {
            margin-bottom: 1rem;
        }
        
        /* Reference table */
        .reference-table {
            width: 100%;
            border-collapse: collapse;
            margin: 1.5rem 0;
        }
        
        .reference-table th, .reference-table td {
            padding: 0.75rem;
            text-align: left;
            border: 1px solid var(--border-color);
        }
        
        .reference-table th {
            background-color: var(--light-gray);
            font-weight: 600;
        }
        
        .reference-table tr:nth-child(even) {
            background-color: rgba(26, 140, 255, 0.05);
        }
        
        /* Hydration-specific styles */
        .hydration-formula-box {
            background-color: rgba(26, 140, 255, 0.05);
            border-radius: 8px;
            padding: 1.5rem;
            margin: 1.5rem 0;
            border: 1px solid rgba(26, 140, 255, 0.2);
        }
        
        .formula-text {
            font-family: 'Courier New', monospace;
            font-size: 1.1rem;
            color: var(--accent-color);
            margin-bottom: 0.5rem;
        }
        
        .formula-title {
            font-weight: 600;
            margin-bottom: 0.5rem;
            color: var(--hydration-blue);
        }
        
        .hydration-applications {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
            gap: 1rem;
            margin: 1.5rem 0;
        }
        
        .application-card {
            background: white;
            border-radius: 8px;
            padding: 1.25rem;
            border: 1px solid var(--border-color);
            box-shadow: 0 2px 4px rgba(0,0,0,0.05);
        }
        
        .application-icon {
            width: 48px;
            height: 48px;
            border-radius: 8px;
            background-color: rgba(26, 140, 255, 0.1);
            display: flex;
            align-items: center;
            justify-content: center;
            margin-bottom: 1rem;
            color: var(--hydration-blue);
            font-size: 1.25rem;
        }
        
        .application-title {
            font-weight: 600;
            margin-bottom: 0.5rem;
            color: var(--text-color);
        }
        
        .application-desc {
            color: var(--text-muted);
            font-size: 0.9rem;
        }
        
        /* Intensity indicators */
        .intensity-badge {
            display: inline-block;
            padding: 0.25rem 0.75rem;
            border-radius: 20px;
            font-size: 0.85rem;
            font-weight: 500;
            margin-right: 0.5rem;
        }
        
        .intensity-low {
            background-color: rgba(40, 167, 69, 0.1);
            color: #28a745;
        }
        
        .intensity-medium {
            background-color: rgba(255, 193, 7, 0.1);
            color: #ffc107;
        }
        
        .intensity-high {
            background-color: rgba(220, 53, 69, 0.1);
            color: #dc3545;
        }
        
        /* Range slider styling */
        .form-range {
            width: 100%;
            height: 1rem;
            padding: 0;
            background-color: transparent;
            -webkit-appearance: none;
        }
        
        .form-range:focus {
            outline: none;
        }
        
        .form-range::-webkit-slider-thumb {
            width: 1rem;
            height: 1rem;
            margin-top: -0.5rem;
            background-color: var(--hydration-blue);
            border: 0;
            border-radius: 1rem;
            -webkit-appearance: none;
        }
        
        .form-range::-webkit-slider-runnable-track {
            width: 100%;
            height: 0.5rem;
            cursor: pointer;
            animate: 0.2s;
            background: var(--light-gray);
            border-radius: 0.5rem;
        }
        
        .slider-value {
            background-color: var(--hydration-blue);
            color: white;
            padding: 0.25rem 0.5rem;
            border-radius: 4px;
            font-size: 0.8rem;
            margin-left: 0.5rem;
        }
        
        /* Hydration chart styling */
        .hydration-chart-container {
            position: relative;
            height: 350px;
            width: 100%;
            margin: 1.5rem 0;
        }
        
        /* Hydration classification */
        .hydration-classification {
            padding: 1rem;
            border-radius: 8px;
            margin: 1rem 0;
            border-left: 5px solid;
        }
        
        .hydration-low {
            background-color: rgba(220, 53, 69, 0.1);
            border-left-color: #dc3545;
        }
        
        .hydration-adequate {
            background-color: rgba(40, 167, 69, 0.1);
            border-left-color: #28a745;
        }
        
        .hydration-excessive {
            background-color: rgba(255, 193, 7, 0.1);
            border-left-color: #ffc107;
        }
        
        /* Drink calculator */
        .drink-calculator {
            background-color: rgba(26, 140, 255, 0.05);
            border-radius: 8px;
            padding: 1.5rem;
            margin: 1.5rem 0;
            border: 1px solid rgba(26, 140, 255, 0.2);
        }
        
        /* Sport icons */
        .sport-icon {
            width: 60px;
            height: 60px;
            border-radius: 8px;
            background-color: rgba(26, 140, 255, 0.1);
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 1rem;
            color: var(--hydration-blue);
            font-size: 1.5rem;
        }
        
        /* Hydration timeline */
        .timeline {
            position: relative;
            margin: 2rem 0;
        }
        
        .timeline::before {
            content: '';
            position: absolute;
            left: 50%;
            transform: translateX(-50%);
            width: 2px;
            height: 100%;
            background-color: var(--hydration-blue);
        }
        
        .timeline-item {
            display: flex;
            align-items: center;
            margin-bottom: 2rem;
            position: relative;
        }
        
        .timeline-item:nth-child(odd) {
            flex-direction: row-reverse;
        }
        
        .timeline-content {
            width: 45%;
            padding: 1rem;
            background-color: white;
            border-radius: 8px;
            border: 1px solid var(--border-color);
            box-shadow: 0 2px 4px rgba(0,0,0,0.05);
        }
        
        .timeline-marker {
            width: 20px;
            height: 20px;
            border-radius: 50%;
            background-color: var(--hydration-blue);
            position: absolute;
            left: 50%;
            transform: translateX(-50%);
            z-index: 1;
        }
        
        /* 特殊人群调整区域 */
        .special-population {
            background-color: rgba(253, 126, 20, 0.05);
            border-radius: 8px;
            padding: 1.5rem;
            margin: 1.5rem 0;
            border: 1px solid rgba(253, 126, 20, 0.2);
        }
        
        .population-factor-card {
            background: white;
            border-radius: 8px;
            padding: 1rem;
            border: 1px solid var(--border-color);
            margin-bottom: 1rem;
            cursor: pointer;
            transition: all 0.3s;
        }
        
        .population-factor-card:hover {
            border-color: var(--warning-orange);
            background-color: rgba(253, 126, 20, 0.05);
        }
        
        .population-factor-card.active {
            border: 2px solid var(--warning-orange);
            background-color: rgba(253, 126, 20, 0.1);
        }
        
        .population-name {
            font-weight: 600;
            margin-bottom: 0.25rem;
            color: var(--text-color);
        }
        
        .population-desc {
            color: var(--text-muted);
            font-size: 0.9rem;
        }
        
        /* 历史记录区域 */
        .history-container {
            background-color: rgba(26, 140, 255, 0.05);
            border-radius: 8px;
            padding: 1.5rem;
            margin: 1.5rem 0;
            border: 1px solid rgba(26, 140, 255, 0.2);
        }
        
        .history-list {
            max-height: 300px;
            overflow-y: auto;
        }
        
        .history-item {
            background: white;
            border-radius: 6px;
            padding: 1rem;
            border: 1px solid var(--border-color);
            margin-bottom: 0.75rem;
            transition: all 0.3s;
        }
        
        .history-item:hover {
            border-color: var(--hydration-blue);
            background-color: rgba(26, 140, 255, 0.05);
        }
        
        /* 免责声明 */
        .disclaimer-box {
            background-color: rgba(108, 117, 125, 0.05);
            border-left: 3px solid #6c757d;
            padding: 1rem;
            border-radius: 0 4px 4px 0;
            margin: 1.5rem 0;
            font-size: 0.9rem;
        }
        
        /* 极端情况警告 */
        .extreme-warning {
            background-color: rgba(220, 53, 69, 0.1);
            border-left: 3px solid #dc3545;
            padding: 1rem;
            border-radius: 0 4px 4px 0;
            margin: 1rem 0;
            display: none;
        }
        
        /* 设置保存提示 */
        .settings-saved {
            position: fixed;
            bottom: 20px;
            left: 50%;
            transform: translateX(-50%);
            background-color: #28a745;
            color: white;
            padding: 0.75rem 1.5rem;
            border-radius: 6px;
            box-shadow: 0 4px 12px rgba(0,0,0,0.15);
            z-index: 1060;
            display: none;
            font-weight: 500;
        }