:root {
            --main-color: #1A48EE;
            --secondary-color: #008AFF;
            --secondary-background: #f9f9f9;
            --main-background: #e5f3ff;
            --color-white: #ffffff;
            --color-error: #c53030;
            --color-error-background: #fef2f2;
            --border-color: #e2e8f0;
            --color-gray: #4a5568;
            --color-dark-gray: #1F2937;
            --focus-ring-color: rgba(26, 72, 238, 0.3);
        }
        .wrapper { padding: 2rem 1rem; }
        h1 {
            text-align: center;
            margin-top: 0px;
            color: var(--color-dark-gray);
            font-size: 2.25rem;
            font-weight: bold;
        }
        h2 {
            font-size: 1.5rem;
            font-weight: 600;
            color: var(--color-dark-gray);
            margin-top: 2rem;
            margin-bottom: 1rem;
        }
        h3 {
            font-size: 1.25rem;
            font-weight: 600;
        }
        .instructions h3{
             font-size: 1.1rem;
             font-weight: 600;
             margin-bottom: 0.5rem;
        }
        p { margin: 0 0 16px; color: var(--color-gray); line-height: 1.6; }
        .articlecontainer { margin: auto; max-width: 1024px; width: 100%; }
        .hidden { display: none; }
        .card {
            background-color: var(--color-white);
            border-radius: 16px;
            border: 1px solid var(--border-color);
            box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
            padding: 2.5rem;
            margin-bottom: 2rem;
        }
        .instructions {
            background-color: var(--color-white);
            padding: 1.5rem;
            border-radius: 8px;
            box-shadow: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -1px rgba(0,0,0,0.06);
            margin-bottom: 1.5rem;
        }
        .instructions ul { list-style-position: inside; padding-left:0; margin-left: 1rem; }
        .instructions li { margin-bottom: 0.5rem; }
        .ad-container { width: 100%; margin: 2rem auto; text-align: center; min-height: 90px; }
        .visually-hidden {
            position: absolute; width: 1px; height: 1px;
            padding: 0; margin: -1px; overflow: hidden;
            clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0;
        }
        
        .grid-container {
            display: grid;
            grid-template-columns: 1fr;
            gap: 2.5rem;
        }
        @media (min-width: 1024px) {
            .grid-container { grid-template-columns: 2fr 3fr; }
        }

        .form-section h2 {
            font-size: 1.25rem;
            border-bottom: 1px solid var(--border-color);
            padding-bottom: 0.75rem;
            margin-bottom: 1.5rem;
        }
        .form-group { margin-bottom: 1.25rem; }
        .form-group label {
            display: block; font-size: 0.875rem; font-weight: 500;
            color: var(--color-dark-gray); margin-bottom: 0.5rem;
        }
        .form-group label span { color: var(--color-gray); font-weight: 400; }
        
        input[type="text"], input[type="number"], input[type="date"] {
            width: 100%; padding: 0.75rem; border: 1px solid #cbd5e0;
            border-radius: 0.5rem; font-size: 1rem;
            transition: border-color 0.2s, box-shadow 0.2s;
        }
        input[type="text"]:focus, input[type="number"]:focus, input[type="date"]:focus {
            outline: none; border-color: var(--main-color);
            box-shadow: 0 0 0 3px var(--focus-ring-color);
        }
        
        .button-group-toggle {
            display: flex;
            margin-top: 0.5rem;
        }
        .button-group-toggle label {
            border: 1px solid #cbd5e0;
            padding: 0.65rem 1rem;
            background-color: var(--secondary-background);
            color: var(--color-gray);
            font-weight: 500;
            cursor: pointer;
            transition: background-color 0.2s, color 0.2s;
            font-size: 1rem;
            line-height: 1.5;
            white-space: nowrap;
            flex: 1;
            text-align: center;
        }
        .button-group-toggle label:hover {
            background-color: #e5e7eb;
        }
        .button-group-toggle label:first-of-type {
            border-top-left-radius: 6px;
            border-bottom-left-radius: 6px;
        }
        .button-group-toggle label:not(:first-of-type) {
            border-left: 0;
        }
        .button-group-toggle label:last-of-type {
            border-top-right-radius: 6px;
            border-bottom-right-radius: 6px;
        }
        .button-group-toggle input:checked + label {
            background-color: var(--main-color);
            color: var(--color-white);
            border-color: var(--main-color);
            z-index: 1;
        }
        
        .calculate-btn {
            width: 100%; background-color: var(--main-color); color: var(--color-white);
            font-weight: 600; padding: 0.85rem 2rem; border: none;
            border-radius: 0.5rem; transition: background-color 0.2s, transform 0.2s;
            cursor: pointer; font-size: 1rem; margin-top: 1.5rem;
        }
        .calculate-btn:hover { background-color: #2142c2; transform: translateY(-1px); }
        .results-section {
            min-width: 0; /* Fix for grid item overflow */
        }
        .results-section h2, .results-section h3 {
            border-bottom: 1px solid var(--border-color);
            padding-bottom: 0.75rem; margin-bottom: 1.5rem;
        }
        .monthly-payment-summary {
            background: var(--main-color);
            padding: 2rem; border-radius: 12px; text-align: center;
            margin-bottom: 2rem; color: var(--color-white);
        }
        .monthly-payment-summary .label { font-size: 1rem; color:var(--color-white); font-weight: bold; background-color: var(--main-color);}
        .monthly-payment-summary .amount { font-size: 2.75rem; font-weight: 700; margin: 0.5rem 0; color:var(--color-white);}
        
        .payment-breakdown-grid {
            display: grid; grid-template-columns: 1fr 1fr;
            gap: 1rem; margin-bottom: 2.5rem;
        }
        .payment-breakdown-grid .breakdown-item {
            padding: 1.25rem; border-radius: 8px; text-align: center;
            border: 1px solid var(--border-color);
        }
        .payment-breakdown-grid .breakdown-item .label {
            font-size: 0.875rem; font-weight: 500; color: var(--color-gray);
        }
        .payment-breakdown-grid .breakdown-item .amount {
            font-size: 1.25rem; font-weight: 600; color: var(--color-dark-gray); margin-top: 0.25rem;
        }
        
        .initial-message {
            display: flex; align-items: center; justify-content: center;
            height: 100%; background-color: var(--secondary-background);
            border-radius: 12px; padding: 2rem; text-align: center;
            color: var(--color-gray); border: 2px dashed var(--border-color);
        }
        
        .amortization-table-container {
            max-height: 400px; overflow-y: auto; overflow-x: auto;
            width: 100%;
            border: 1px solid var(--border-color); border-radius: 8px;
        }
        .amortization-table {
            width: 100%; border-collapse: collapse; text-align: left;
        }
        .amortization-table th, .amortization-table td {
            padding: 0.75rem 1rem; border-bottom: 1px solid var(--border-color);
        }
        .amortization-table thead {
            background-color: var(--secondary-background); position: sticky;
            top: 0; font-size: 0.75rem; text-transform: uppercase;
            color: var(--color-gray);
        }
        .amortization-table tbody tr:last-child td { border-bottom: none; }
        .amortization-table tbody tr:hover { background-color: #F9FAFB; }
        .amortization-table .text-right { text-align: right; }

        .error-message {
            background-color: var(--color-error-background);
            color: var(--color-error);
            border-left: 4px solid var(--color-error);
            padding: 1rem;
            margin-bottom: 1.5rem;
            border-radius: 4px;
        }
        .error-message p { margin: 0; font-weight: 500; }
       @media (max-width: 629px) {
            .wrapper { padding: 1rem 0.5rem; }
            h1 { font-size: 1.75rem; }
            .card { padding: 1.5rem; }
            .results-section h2, .results-section h3 {
                font-size: 1.25rem;
            }
            .payment-breakdown-grid { grid-template-columns: 1fr; }
            .payment-breakdown-grid .breakdown-item {
                padding: 1rem;
            }
            .monthly-payment-summary {
                padding: 1.5rem;
                overflow-wrap: break-word;
            }
            .monthly-payment-summary .amount { font-size: 2.25rem; }
            .amortization-table th, .amortization-table td {
                padding: 0.5rem 0.75rem;
                font-size: 0.9rem;
            }
            .button-group-toggle {
                flex-direction: column;
            }
            .button-group-toggle label {
                border-radius: 0 !important;
                border-left: 1px solid #cbd5e0;
            }
            .button-group-toggle label:not(:first-of-type) {
                border-top: 0;
            }
            .button-group-toggle label:first-of-type {
                border-top-left-radius: 6px !important;
                border-top-right-radius: 6px !important;
            }
            .button-group-toggle label:last-of-type {
                border-bottom-left-radius: 6px !important;
                border-bottom-right-radius: 6px !important;
            }
        }