: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;
            --hex-color: #e83e8c;
            --binary-color: #6f42c1;
            --decimal-color: #2c7da0;
            --octal-color: #20c997;
            --bitwise-color: #fd7e14;
        }
         .page-header {
            background: linear-gradient(135deg, rgba(232, 62, 140, 0.1) 0%, rgba(44, 125, 160, 0.1) 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);
        }
        .calc-mode-tabs {
            display: flex;
            flex-wrap: wrap;
            border-bottom: 1px solid var(--border-color);
            margin-bottom: 1.5rem;
        }
        .calc-tab {
            padding: 0.75rem 1.15rem;
            background: none;
            border: none;
            border-bottom: 3px solid transparent;
            font-weight: 600;
            color: var(--text-muted);
            transition: all 0.3s;
            cursor: pointer;
        }
        .calc-tab:hover {
            color: var(--primary-color);
        }
        .calc-tab.active {
            color: var(--primary-color);
            border-bottom: 3px solid var(--primary-color);
        }
        .calc-display {
            background-color: #1a1a1a;
            color: #00ff00;
            font-family: 'Courier New', monospace;
            font-size: 1.8rem;
            padding: 1.5rem;
            border-radius: 8px;
            text-align: right;
            margin-bottom: 1.5rem;
            min-height: 80px;
            overflow-x: auto;
            white-space: nowrap;
            border: 2px solid #333;
        }
        .calc-expression {
            font-size: 1rem;
            color: #aaa;
            min-height: 1.5rem;
            margin-bottom: 0.5rem;
        }
        .calc-result {
            font-size: 1.8rem;
            font-weight: 600;
        }
        .calc-buttons {
            display: grid;
            grid-template-columns: repeat(6, 1fr);
            gap: 8px;
            margin-bottom: 1.5rem;
        }
        .calc-button {
            padding: 1rem 0.5rem;
            font-size: 1.1rem;
            font-weight: 600;
            border: 1px solid var(--border-color);
            border-radius: 6px;
            background-color: white;
            transition: all 0.2s;
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: center;
        }
        .calc-button:hover {
            transform: translateY(-2px);
            box-shadow: 0 4px 8px rgba(0,0,0,0.1);
        }
        .calc-button.number {
            background-color: #f8f9fa;
        }
        .calc-button.hex {
            background-color: rgba(232, 62, 140, 0.1);
            color: var(--hex-color);
            font-weight: 700;
        }
        .calc-button.operation {
            background-color: rgba(44, 125, 160, 0.1);
            color: var(--primary-color);
        }
        .calc-button.bitwise {
            background-color: rgba(253, 126, 20, 0.1);
            color: var(--bitwise-color);
        }
        .calc-button.equals {
            background-color: var(--primary-color);
            color: white;
        }
        .calc-button.clear {
            background-color: rgba(220, 53, 69, 0.1);
            color: #dc3545;
        }
        .calc-button.function {
            background-color: rgba(111, 66, 193, 0.1);
            color: var(--binary-color);
        }
        .form-control:focus {
            border-color: var(--primary-color);
            box-shadow: 0 0 0 3px rgba(44, 125, 160, 0.15);
        }
        .input-mode-selector {
            display: flex;
            flex-wrap: wrap;
            gap: 0.5rem;
            margin-bottom: 1rem;
        }
        .mode-btn {
            padding: 0.5rem 1rem;
            border: 1px solid var(--border-color);
            border-radius: 4px;
            background-color: white;
            color: var(--text-muted);
            cursor: pointer;
            transition: all 0.3s;
        }
        .mode-btn:hover {
            background-color: var(--light-gray);
        }
        .mode-btn.active {
            background-color: var(--hex-color);
            color: white;
            border-color: var(--hex-color);
        }
        .mode-btn.decimal.active {
            background-color: var(--decimal-color);
            border-color: var(--decimal-color);
        }
        .mode-btn.binary.active {
            background-color: var(--binary-color);
            border-color: var(--binary-color);
        }
        .mode-btn.octal.active {
            background-color: var(--octal-color);
            border-color: var(--octal-color);
        }
        .conversion-results {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
            gap: 1rem;
            margin-top: 1rem;
        }
        .conversion-card {
            background: white;
            border-radius: 6px;
            padding: 1rem;
            border: 1px solid var(--border-color);
            box-shadow: 0 2px 4px rgba(0,0,0,0.05);
        }
        .conversion-type {
            font-size: 0.9rem;
            color: var(--text-muted);
            margin-bottom: 0.5rem;
        }
        .conversion-value {
            font-family: 'Courier New', monospace;
            font-size: 1.2rem;
            font-weight: 600;
            color: var(--text-color);
            word-break: break-all;
        }
        .hex-representation {
            display: flex;
            flex-wrap: wrap;
            gap: 4px;
            margin: 1rem 0;
        }
        .hex-digit {
            width: 40px;
            height: 40px;
            display: flex;
            align-items: center;
            justify-content: center;
            border: 1px solid #ddd;
            border-radius: 4px;
            font-family: 'Courier New', monospace;
            font-weight: 600;
            background-color: white;
        }
        .hex-digit.active {
            background-color: rgba(232, 62, 140, 0.1);
            border-color: var(--hex-color);
        }
        .hex-digit.index {
            font-size: 0.7rem;
            color: var(--text-muted);
            background-color: transparent;
            border: none;
        }
        .hex-box {
            background-color: rgba(232, 62, 140, 0.05);
            border-left: 3px solid var(--hex-color);
            padding: 1rem;
            border-radius: 0 4px 4px 0;
            margin: 1.5rem 0;
        }
        .bitwise-box {
            background-color: rgba(253, 126, 20, 0.05);
            border-left: 3px solid var(--bitwise-color);
            padding: 1rem;
            border-radius: 0 4px 4px 0;
            margin: 1.5rem 0;
        }
        .hex-table {
            width: 100%;
            border-collapse: collapse;
            margin: 1.5rem 0;
        }
        .hex-table th, .hex-table td {
            padding: 0.75rem;
            text-align: center;
            border: 1px solid var(--border-color);
        }
        .hex-table th {
            background-color: var(--light-gray);
            font-weight: 600;
        }
        .hex-table tr:nth-child(even) {
            background-color: rgba(44, 125, 160, 0.05);
        }
        .operation-examples {
            display: flex;
            flex-wrap: wrap;
            gap: 0.5rem;
            margin: 1rem 0;
        }
        .example-btn {
            background-color: rgba(232, 62, 140, 0.1);
            border: 1px solid rgba(232, 62, 140, 0.2);
            border-radius: 4px;
            padding: 0.5rem 0.75rem;
            font-size: 0.9rem;
            color: var(--hex-color);
            cursor: pointer;
            transition: all 0.2s;
            font-family: 'Courier New', monospace;
        }
        .example-btn:hover {
            background-color: rgba(232, 62, 140, 0.2);
            transform: translateY(-2px);
        }
        @media (max-width: 992px) {
            .calc-buttons {
                grid-template-columns: repeat(4, 1fr);
            }
        }
        @media (max-width: 768px) {
            .calc-buttons {
                grid-template-columns: repeat(3, 1fr);
            }
            .conversion-results {
                grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
            }
        }
        .hex-visualization {
            padding: 1rem;
            background-color: white;
            border-radius: 8px;
            border: 1px solid var(--border-color);
            margin: 1rem 0;
        }
        .digit-explanation {
            font-size: 0.9rem;
            color: var(--text-muted);
            margin-top: 0.5rem;
        }
        .base-label {
            display: inline-block;
            padding: 0.2rem 0.5rem;
            border-radius: 4px;
            font-size: 0.8rem;
            font-weight: 600;
            margin-left: 0.5rem;
        }
        .base-hex {
            background-color: rgba(232, 62, 140, 0.1);
            color: var(--hex-color);
        }
        .base-decimal {
            background-color: rgba(44, 125, 160, 0.1);
            color: var(--primary-color);
        }
        .base-binary {
            background-color: rgba(111, 66, 193, 0.1);
            color: var(--binary-color);
        }
        .base-octal {
            background-color: rgba(32, 201, 151, 0.1);
            color: var(--octal-color);
        }
        .function-buttons {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 8px;
            margin-bottom: 1rem;
        }
        .function-btn {
            padding: 0.75rem;
            font-size: 0.9rem;
            font-weight: 600;
            border: 1px solid var(--border-color);
            border-radius: 6px;
            background-color: white;
            cursor: pointer;
            transition: all 0.2s;
        }
        .function-btn:hover {
            background-color: rgba(111, 66, 193, 0.1);
            transform: translateY(-2px);
        }
        .hex-0 { color: #6c757d; }
        .hex-1 { color: #007bff; }
        .hex-2 { color: #28a745; }
        .hex-3 { color: #17a2b8; }
        .hex-4 { color: #ffc107; }
        .hex-5 { color: #dc3545; }
        .hex-6 { color: #e83e8c; }
        .hex-7 { color: #6f42c1; }
        .hex-8 { color: #20c997; }
        .hex-9 { color: #fd7e14; }
        .hex-a { color: #e83e8c; font-weight: bold; }
        .hex-b { color: #6610f2; font-weight: bold; }
        .hex-c { color: #28a745; font-weight: bold; }
        .hex-d { color: #17a2b8; font-weight: bold; }
        .hex-e { color: #ffc107; font-weight: bold; }
        .hex-f { color: #dc3545; font-weight: bold; }
        .bitwise-grid {
            display: grid;
            grid-template-columns: auto 1fr;
            gap: 10px;
            margin-top: 10px;
        }
        .bit-row {
            display: contents;
        }
        .bit-label {
            font-weight: 600;
            color: var(--text-muted);
        }
        .bit-values {
            font-family: 'Courier New', monospace;
            word-break: break-all;
        }
        .bit-values.highlight {
            color: var(--hex-color);
            font-weight: bold;
        }
        .bigint-warning {
            background-color: rgba(255, 193, 7, 0.1);
            border-left: 3px solid var(--warning-color);
            padding: 0.75rem;
            border-radius: 0 4px 4px 0;
            margin: 1rem 0;
            font-size: 0.9rem;
        }
        .negative-value {
            color: #dc3545;
        }
        .twos-complement-steps {
            background-color: rgba(111, 66, 193, 0.05);
            padding: 1rem;
            border-radius: 6px;
            margin-top: 1rem;
            font-family: 'Courier New', monospace;
            font-size: 0.9rem;
        }
        .step-line {
            margin-bottom: 0.5rem;
        }
        .step-line:last-child {
            margin-bottom: 0;
        }