:root {
            /* DHGS Corporate Design Colors */
            --dhgs-blue: #004494;
            --dhgs-blue-light: rgba(0, 68, 148, 0.1);
            --dhgs-orange: #ff8800;
            --dhgs-orange-light: rgba(255, 136, 0, 0.1);
            
            --bg-color: #f4f7f6;
            --card-bg: #ffffff;
            --text-main: #1a202c;
            --secondary: #4a5568;
            --border: #e2e8f0;
        }

        .calc-container {
            max-width: 1200px;
            margin: 0 auto;
            background: var(--card-bg);
            border-radius: 8px;
            box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
            overflow: hidden;
        }
        
        /* --- Premium Header --- */
        .app-header {
            background-color: var(--dhgs-blue);
            color: white;
            padding: 1.5rem 2rem;
            text-align: center;
            border-bottom: 4px solid var(--dhgs-orange);
        }
        .app-header h1 {
            margin: 0;
            font-size: 2rem;
            letter-spacing: 0.02em;
            font-weight: 700;
            text-transform: uppercase;
        }

        .grid-layout {
            display: grid;
            grid-template-columns: 1fr 2fr;
        }


        .calc-sidebar {
            padding: 2.5rem;
            background-color: #fafbfc;
            border-right: 1px solid var(--border);
        }
        .main-content {
            padding: 2.5rem;
            display: flex;
            flex-direction: column;
        }
        
        .calc-container  .section-title { 
            font-size: 1.15rem; 
            color: var(--dhgs-blue); 
            margin-top: 1.5rem; 
            margin-bottom: 1rem;
            padding-bottom: 0.5rem;
            border-bottom: 2px solid var(--border);
            text-transform: uppercase;
            letter-spacing: 0.05em;
            font-weight: 700;
        }
        .calc-container  .section-title:first-child {
            margin-top: 0;
        }
        
        .form-group { margin-bottom: 1.25rem; }
        .calc-container  label {
            display: block;
            font-weight: 700;
            margin-bottom: 0.5rem;
            font-size: 0.95rem;
            color: var(--secondary);
        }
       .calc-container select, .calc-container input {
            width: 100%;
            padding: 0.8rem;
            border: 1px solid #cbd5e0;
            border-radius: 4px;
            font-size: 1rem;
            font-family: 'PT Sans', sans-serif;
            box-sizing: border-box;
            background-color: #fff;
            transition: all 0.2s ease;
        }
        .calc-container select:focus, .calc-container input:focus {
            outline: none;
            border-color: var(--dhgs-orange);
            box-shadow: 0 0 0 3px var(--dhgs-orange-light);
        }
        .calc-container select:disabled {
            background-color: #edf2f7;
            color: #a0aec0;
            cursor: not-allowed;
            border-color: #e2e8f0;
        }
        .hidden { display: none !important; }
        
        /* Premium Summary Boxes */
        .summary-boxes {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 1.5rem;
            margin-bottom: 2rem;
        }
        .summary-box {
            padding: 1.5rem;
            border-radius: 6px;
            text-align: center;
            background: #fff;
            border: 1px solid var(--border);
            box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05);
        }
        .summary-title { 
            font-size: 0.9rem; 
            color: var(--secondary); 
            text-transform: uppercase; 
            font-weight: 700; 
            letter-spacing: 0.05em; 
        }
        .summary-value { 
            font-size: 2.2rem; 
            font-weight: 700; 
            margin-top: 0.5rem; 
        }
        .val-orange { color: var(--dhgs-orange); }
        .val-blue { color: var(--dhgs-blue); }
        .val-red { color: #e53e3e; }
        
        .chart-container {
            position: relative;
            height: 450px;
            width: 100%;
            flex-grow: 1;
        }

        @media (max-width: 860px) {
            .grid-layout, .summary-boxes { grid-template-columns: 1fr; }
            .main-content { padding: 0;}
            .calc-container {box-shadow: 0 0px 0px 0px rgba(0, 0, 0, 0.1); }
            .calc-sidebar { padding: 2.5rem 0; background-color: transparent; border-right: 0px solid #fff;}
}