: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;
            --uart-color: #007bff;
            --spi-color: #6f42c1;
            --i2c-color: #e83e8c;
            --error-color: #dc3545;
        }
         
        .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);
        }
         
        /* Form Styles with Validation */
        .form-label {
            font-weight: 600;
            margin-bottom: 0.5rem;
            color: var(--text-color);
        }
        
        .form-control {
            border: 1px solid #ddd;
            border-radius: 6px;
            padding: 0.75rem;
            transition: all 0.3s;
        }
        
        .form-control:focus {
            border-color: var(--primary-color);
            box-shadow: 0 0 0 3px rgba(44, 125, 160, 0.15);
        }
        
        .form-control.is-invalid {
            border-color: var(--error-color);
            background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 12 12' width='12' height='12' fill='none' stroke='%23dc3545'%3e%3ccircle cx='6' cy='6' r='4.5'/%3e%3cpath stroke-linejoin='round' d='M5.8 3.6h.4L6 6.5z'/%3e%3ccircle cx='6' cy='8.2' r='.6' fill='%23dc3545' stroke='none'/%3e%3c/svg%3e");
            background-repeat: no-repeat;
            background-position: right calc(0.375em + 0.1875rem) center;
            background-size: calc(0.75em + 0.375rem) calc(0.75em + 0.375rem);
        }
        
        .form-control.is-valid {
            border-color: var(--success-color);
            background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 8 8'%3e%3cpath fill='%23198754' d='M2.3 6.73L.6 4.53c-.4-1.04.46-1.4 1.1-.8l1.1 1.4 3.4-3.8c.6-.63 1.6-.27 1.2.7l-4 4.6c-.43.5-.8.4-1.1.1z'/%3e%3c/svg%3e");
            background-repeat: no-repeat;
            background-position: right calc(0.375em + 0.1875rem) center;
            background-size: calc(0.75em + 0.375rem) calc(0.75em + 0.375rem);
        }
        
        .invalid-feedback {
            display: none;
            width: 100%;
            margin-top: 0.25rem;
            font-size: 0.875em;
            color: var(--error-color);
        }
        
        .was-validated .form-control:invalid ~ .invalid-feedback,
        .form-control.is-invalid ~ .invalid-feedback {
            display: block;
        }
        
        .input-group-text {
            background-color: var(--light-gray);
            border: 1px solid #ddd;
        }
        
        .input-group .form-control.is-invalid {
            z-index: 3;
        }
        
     
        
        .btn-outline-secondary {
            font-weight: 600;
            border-radius: 6px;
            padding: 0.75rem 1.5rem;
        }
        
        /* MCU Selector */
        .mcu-selector {
            background-color: rgba(44, 125, 160, 0.05);
            border-radius: 8px;
            padding: 1rem;
            margin-bottom: 1.5rem;
            border: 1px solid rgba(44, 125, 160, 0.2);
        }
        
        .mcu-params {
            margin-top: 1rem;
            padding: 0.75rem;
            background-color: white;
            border-radius: 6px;
            border: 1px solid var(--border-color);
        }
        
        /* Protocol Tabs */
        .protocol-tabs {
            display: flex;
            background-color: var(--light-gray);
            border-radius: 8px;
            padding: 5px;
            margin-bottom: 1.5rem;
            flex-wrap: wrap;
        }
        
        .protocol-tab {
            flex: 1;
            text-align: center;
            padding: 1rem;
            border-radius: 6px;
            cursor: pointer;
            transition: all 0.3s;
            font-weight: 600;
            min-width: 150px;
            margin: 2px;
        }
        
        .protocol-tab.active {
            background-color: white;
            box-shadow: 0 2px 8px rgba(0,0,0,0.1);
        }
        
        .uart-tab.active {
            border-bottom: 3px solid var(--uart-color);
            color: var(--uart-color);
        }
        
        .spi-tab.active {
            border-bottom: 3px solid var(--spi-color);
            color: var(--spi-color);
        }
        
        .i2c-tab.active {
            border-bottom: 3px solid var(--i2c-color);
            color: var(--i2c-color);
        }
        
        .protocol-icon {
            margin-right: 8px;
            font-size: 1.2rem;
        }
        
        /* Protocol-specific forms */
        .protocol-form {
            display: none;
        }
        
        .protocol-form.active {
            display: block;
        }
        
        /* I2C Timing Parameters */
        .i2c-timing-section {
            background-color: rgba(232, 62, 140, 0.05);
            border: 1px solid rgba(232, 62, 140, 0.2);
            border-radius: 6px;
            padding: 1rem;
            margin: 1rem 0;
        }
        
        .timing-params {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
            gap: 1rem;
            margin-top: 1rem;
        }
        
        /* Result Area */
        .result-container {
            background-color: var(--light-gray);
            border-radius: 6px;
            padding: 1.5rem;
            margin-top: 1.5rem;
            position: relative;
            border: 1px solid var(--border-color);
        }
        
        .result-title {
            font-weight: 600;
            margin-bottom: 0.75rem;
            color: var(--primary-color);
        }
        
        /* Communication Summary */
        .communication-summary {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 1.5rem;
            margin: 2rem 0;
        }
        
        .communication-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);
        }
        
        .communication-item h4 {
            font-size: 1rem;
            color: var(--text-muted);
            margin-bottom: 0.5rem;
        }
        
        .communication-item .value {
            font-size: 1.5rem;
            font-weight: 700;
            margin-bottom: 0.25rem;
        }
        
        .communication-item .detail {
            font-size: 0.9rem;
            color: var(--text-muted);
            margin-top: 0.5rem;
        }
        
        /* Protocol-specific colors */
        .uart-color {
            color: var(--uart-color);
        }
        
        .spi-color {
            color: var(--spi-color);
        }
        
        .i2c-color {
            color: var(--i2c-color);
        }
        
        .uart-bg {
            background-color: rgba(0, 123, 255, 0.1);
            border-left: 4px solid var(--uart-color);
        }
        
        .spi-bg {
            background-color: rgba(111, 66, 193, 0.1);
            border-left: 4px solid var(--spi-color);
        }
        
        .i2c-bg {
            background-color: rgba(232, 62, 140, 0.1);
            border-left: 4px solid var(--i2c-color);
        }
        
        /* Content Sections */
        .section-title {
            font-weight: 600;
            margin-bottom: 1rem;
            color: var(--primary-color);
            padding-bottom: 0.5rem;
            border-bottom: 1px solid var(--border-color);
        }
        
        .protocol-comparison {
            width: 100%;
            border-collapse: collapse;
            margin: 1.5rem 0;
        }
        
        .protocol-comparison th, .protocol-comparison td {
            padding: 0.75rem;
            text-align: left;
            border: 1px solid var(--border-color);
        }
        
        .protocol-comparison th {
            background-color: var(--light-gray);
            font-weight: 600;
        }
        
        .protocol-comparison tr:hover {
            background-color: rgba(44, 125, 160, 0.05);
        }
        
        /* Info Boxes */
        .info-box {
            background-color: rgba(44, 125, 160, 0.05);
            border-left: 3px solid var(--primary-color);
            padding: 1rem;
            border-radius: 0 4px 4px 0;
            margin: 1.5rem 0;
        }
        
        .uart-info {
            background-color: rgba(0, 123, 255, 0.05);
            border-left: 3px solid var(--uart-color);
        }
        
        .spi-info {
            background-color: rgba(111, 66, 193, 0.05);
            border-left: 3px solid var(--spi-color);
        }
        
        .i2c-info {
            background-color: rgba(232, 62, 140, 0.05);
            border-left: 3px solid var(--i2c-color);
        }
        
        /* Accuracy Indicator */
        .accuracy-indicator {
            display: inline-flex;
            align-items: center;
            padding: 0.25rem 0.5rem;
            border-radius: 4px;
            font-size: 0.9rem;
            font-weight: 600;
            margin-left: 0.5rem;
        }
        
        .accuracy-good {
            background-color: rgba(40, 167, 69, 0.1);
            color: var(--success-color);
        }
        
        .accuracy-warning {
            background-color: rgba(255, 193, 7, 0.1);
            color: var(--warning-color);
        }
        
        .accuracy-error {
            background-color: rgba(220, 53, 69, 0.1);
            color: var(--error-color);
        }
         
        
        /* Export Code Area */
        .code-export {
            background-color: #f8f9fa;
            border: 1px solid #dee2e6;
            border-radius: 6px;
            padding: 1rem;
            margin-top: 1rem;
            font-family: 'Courier New', monospace;
            font-size: 0.9rem;
            white-space: pre-wrap;
            max-height: 300px;
            overflow-y: auto;
        }
        
        .export-buttons {
            display: flex;
            gap: 0.5rem;
            margin-top: 1rem;
        }
        
        /* Signal Visualization */
        .signal-visualization {
            height: 120px;
            width: 100%;
            background-color: #f8f9fa;
            border-radius: 6px;
            border: 1px solid #dee2e6;
            margin: 1rem 0;
            position: relative;
            overflow: hidden;
        }
        
        .signal-label {
            position: absolute;
            font-size: 0.8rem;
            color: #6c757d;
            font-weight: 500;
        }
        
        .signal-line {
            position: absolute;
            height: 2px;
            background-color: #333;
        }
        
        /* Preset Selector */
        .preset-selector {
            background-color: rgba(44, 125, 160, 0.05);
            border-radius: 6px;
            padding: 1rem;
            margin-bottom: 1rem;
        }
        
        /* Responsive Adjustments */
        @media (max-width: 768px) {
            .tool-card {
                padding: 1.5rem;
            }
            
            .communication-summary {
                grid-template-columns: 1fr;
            }
            
            .protocol-tabs {
                flex-direction: column;
            }
            
            .timing-params {
                grid-template-columns: 1fr;
            }
            
            .export-buttons {
                flex-direction: column;
            }
        }
        
        /* 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);
        }
        
        /* Generating indicator */
        .generating-indicator {
            display: none;
            text-align: center;
            padding: 1rem;
            color: var(--text-muted);
        }
        
        /* Baud rate table */
        .baud-table {
            width: 100%;
            border-collapse: collapse;
            margin: 1.5rem 0;
        }
        
        .baud-table th, .baud-table td {
            padding: 0.75rem;
            text-align: center;
            border: 1px solid var(--border-color);
        }
        
        .baud-table th {
            background-color: var(--light-gray);
            font-weight: 600;
        }
        
        .baud-table tr:nth-child(even) {
            background-color: rgba(44, 125, 160, 0.05);
        }
         
        /* Range limits display */
        .range-info {
            font-size: 0.85rem;
            color: var(--text-muted);
            margin-top: 0.25rem;
        }
        
        /* I2C timing parameter fields */
        .timing-input-group {
            display: flex;
            align-items: center;
            margin-bottom: 0.5rem;
        }
        
        .timing-input-group label {
            min-width: 120px;
            margin-right: 10px;
            font-size: 0.9rem;
        }
        
        /* Toggle for auto/manual timing */
        .timing-toggle {
            display: flex;
            align-items: center;
            margin-bottom: 1rem;
        }
        
        .toggle-label {
            margin-right: 10px;
            font-weight: 500;
        }
        
        .toggle-switch {
            position: relative;
            display: inline-block;
            width: 50px;
            height: 24px;
        }
        
        .toggle-switch input {
            opacity: 0;
            width: 0;
            height: 0;
        }
        
        .toggle-slider {
            position: absolute;
            cursor: pointer;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background-color: #ccc;
            transition: .4s;
            border-radius: 24px;
        }
        
        .toggle-slider:before {
            position: absolute;
            content: "";
            height: 16px;
            width: 16px;
            left: 4px;
            bottom: 4px;
            background-color: white;
            transition: .4s;
            border-radius: 50%;
        }
        
        input:checked + .toggle-slider {
            background-color: var(--i2c-color);
        }
        
        input:checked + .toggle-slider:before {
            transform: translateX(26px);
        }