:root {
            --primary-color: #2c7da0;
            --secondary-color: #a9d6e5;
            --accent-color: #01497c;
            --light-gray: #f8f9fa;
            --border-color: #eaeaea;
            --text-color: #333;
            --text-muted: #6c757d;
            --success-color: #28a745;
            --warning-color: #ffc107;
        }
         
        
        .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);
        }
       .result-container{display:none}
        
        .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);
        }
         
        .summary-card {
            background: white;
            border-radius: 8px;
            padding: 1.5rem;
            border: 1px solid var(--border-color);
            margin-bottom: 1.5rem;
            box-shadow: 0 2px 4px rgba(0,0,0,0.05);
        }
        
        .summary-value {
            font-size: 1.5rem;
            font-weight: 700;
            color: var(--primary-color);
            margin-bottom: 0.5rem;
        }
        
        .summary-label {
            color: var(--text-muted);
            font-size: 0.9rem;
        }
        
        /* Chart Container */
        .chart-container {
            position: relative;
            height: 400px;
            width: 100%;
            margin: 2rem 0;
        }
        
        /* Financial Summary */
        .financial-summary {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 1.5rem;
            margin: 2rem 0;
        }
        
        .financial-item {
            background: white;
            border-radius: 8px;
            padding: 1.5rem;
            border: 1px solid var(--border-color);
            box-shadow: 0 2px 4px rgba(0,0,0,0.05);
        }
        
        .financial-item h4 {
            font-size: 1rem;
            color: var(--text-muted);
            margin-bottom: 0.5rem;
        }
        
        .financial-item .value {
            font-size: 1.5rem;
            font-weight: 700;
            color: var(--primary-color);
        }
        
        .financial-item .detail {
            font-size: 0.9rem;
            color: var(--text-muted);
            margin-top: 0.5rem;
        }
         
        /* Responsive Adjustments */
        @media (max-width: 768px) { 
            .financial-summary {
                grid-template-columns: 1fr;
            }
        }
        
        /* Toggle switch for calculation modes */
        .calculation-modes {
            display: flex;
            background-color: var(--light-gray);
            border-radius: 6px;
            padding: 4px;
            margin-bottom: 1.5rem;
            flex-wrap: wrap;
        }
        
        .mode-btn {
            flex: 1;
            text-align: center;
            padding: 0.75rem;
            border-radius: 4px;
            cursor: pointer;
            transition: all 0.3s;
            font-weight: 600;
            min-width: 120px;
            margin: 2px;
        }
        
        .mode-btn.active {
            background-color: var(--primary-color);
            color: white;
        }
       
        /* Hess's Law specific styles */
        .reaction-container {
            margin-bottom: 1.5rem;
            padding: 1rem;
            border: 1px solid var(--border-color);
            border-radius: 6px;
            background-color: white;
        }
        
        .reaction-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 1rem;
        }
        
        .reaction-title {
            font-weight: 600;
            color: var(--primary-color);
        }
        
        .reaction-input {
            display: flex;
            align-items: center;
            flex-wrap: wrap;
            gap: 0.5rem;
        }
        
        .coefficient-input {
            width: 60px;
        }
        
        .compound-input {
            flex: 1;
            min-width: 120px;
        }
        
        .enthalpy-input {
            width: 150px;
        }
        
        .phase-indicator {
            font-size: 0.8rem;
            color: var(--text-muted);
            margin-left: 0.25rem;
        }
        
        .arrow {
            margin: 0 1rem;
            font-weight: 600;
            color: var(--primary-color);
        }
        
        .reaction-controls {
            display: flex;
            gap: 0.5rem;
            margin-top: 1rem;
        }
        
        .reaction-step {
            background-color: rgba(44, 125, 160, 0.05);
            border-radius: 6px;
            padding: 1rem;
            margin-bottom: 1rem;
        }
        
        .step-number {
            background-color: var(--primary-color);
            color: white;
            border-radius: 50%;
            width: 24px;
            height: 24px;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            margin-right: 0.5rem;
            font-size: 0.8rem;
            font-weight: 600;
        }
        
        .step-description {
            margin-top: 0.5rem;
            font-size: 0.9rem;
            color: var(--text-muted);
        }
        
        .energy-level-diagram {
            margin: 2rem 0;
            padding: 1rem;
            background-color: white;
            border-radius: 6px;
            border: 1px solid var(--border-color);
        }
        
        .diagram-container {
            height: 300px;
            position: relative;
        }
        
        /* Math rendering */
        .math-equation {
            font-size: 1.1rem;
            padding: 0.5rem;
            background-color: rgba(255, 255, 255, 0.8);
            border-radius: 4px;
            margin: 0.5rem 0;
        }
        
        /* Advanced options */
        .advanced-options {
            margin-top: 1rem;
            padding: 1rem;
            background-color: var(--light-gray);
            border-radius: 6px;
            border: 1px solid var(--border-color);
        }
        
        .advanced-toggle {
            cursor: pointer;
            color: var(--primary-color);
            font-weight: 600;
        }
        
        .advanced-content {
            margin-top: 1rem;
            display: none;
        }
        
        .advanced-content.show {
            display: block;
        }