: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;
            --image-color: #6f42c1;
            --convert-color: #e83e8c;
        }
         .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);
        }
        .nav-tabs {
            border-bottom: 2px solid var(--border-color);
            margin-bottom: 1.5rem;
        }
        .nav-tabs .nav-tabs .form-control:focus {
            border-color: var(--primary-color);
            box-shadow: 0 0 0 3px rgba(44, 125, 160, 0.15);
        }
        .upload-area {
            border: 2px dashed var(--border-color);
            border-radius: 8px;
            padding: 3rem 2rem;
            text-align: center;
            background-color: var(--light-gray);
            cursor: pointer;
            transition: all 0.3s;
            margin-bottom: 1.5rem;
        }
        .upload-area:hover, .upload-area.dragover {
            border-color: var(--primary-color);
            background-color: rgba(44, 125, 160, 0.05);
        }
        .upload-icon {
            font-size: 3rem;
            color: var(--primary-color);
            margin-bottom: 1rem;
        }
        .color-input-container {
            background-color: rgba(111, 66, 193, 0.05);
            border-left: 3px solid var(--image-color);
            padding: 1.5rem;
            border-radius: 0 6px 6px 0;
            margin: 1.5rem 0;
        }
        .color-sliders {
            margin-bottom: 1.5rem;
        }
        .color-slider-group {
            margin-bottom: 1rem;
        }
        .slider-label {
            display: flex;
            justify-content: space-between;
            margin-bottom: 0.5rem;
        }
        .slider-value {
            font-weight: 600;
            color: var(--primary-color);
        }
        .color-preview-box {
            width: 100%;
            height: 80px;
            border-radius: 6px;
            border: 1px solid var(--border-color);
            margin-bottom: 1.5rem;
            transition: all 0.3s;
        }
        .conversion-options {
            background-color: rgba(111, 66, 193, 0.05);
            border-left: 3px solid var(--image-color);
            padding: 1.5rem;
            border-radius: 0 6px 6px 0;
            margin: 1.5rem 0;
        }
        .method-card {
            background-color: white;
            border: 1px solid var(--border-color);
            border-radius: 6px;
            padding: 1.25rem;
            margin-bottom: 1rem;
            cursor: pointer;
            transition: all 0.3s;
        }
        .method-card:hover {
            border-color: var(--primary-color);
            box-shadow: 0 3px 8px rgba(0,0,0,0.1);
        }
        .method-card.selected {
            border-color: var(--primary-color);
            background-color: rgba(44, 125, 160, 0.05);
        }
        .method-title {
            font-weight: 600;
            color: var(--text-color);
            margin-bottom: 0.5rem;
        }
        .method-description {
            color: var(--text-muted);
            font-size: 0.9rem;
        }
        .method-formula {
            font-family: 'Courier New', monospace;
            background-color: rgba(0,0,0,0.05);
            padding: 0.5rem;
            border-radius: 4px;
            margin-top: 0.5rem;
            font-size: 0.9rem;
        }
        .color-conversion-result {
            display: flex;
            justify-content: space-between;
            align-items: center;
            flex-wrap: wrap;
            gap: 1.5rem;
            margin: 1.5rem 0;
        }
        .color-display {
            flex: 1;
            min-width: 200px;
            text-align: center;
        }
        .color-box {
            width: 100%;
            height: 100px;
            border-radius: 6px;
            border: 1px solid var(--border-color);
            margin-bottom: 1rem;
        }
        .color-label {
            font-weight: 600;
            margin-bottom: 0.5rem;
            font-size: 1.1rem;
        }
        .color-value {
            font-family: 'Courier New', monospace;
            font-size: 1rem;
            padding: 0.5rem;
            background-color: white;
            border-radius: 4px;
            border: 1px solid var(--border-color);
        }
        .conversion-arrow {
            font-size: 2rem;
            color: var(--primary-color);
        }
        .image-preview-container {
            display: flex;
            flex-wrap: wrap;
            gap: 2rem;
            margin: 1.5rem 0;
            justify-content: center;
        }
        .image-preview {
            text-align: center;
            max-width: 100%;
        }
        .preview-image {
            max-width: 100%;
            max-height: 300px;
            border-radius: 6px;
            border: 1px solid var(--border-color);
            box-shadow: 0 3px 10px rgba(0,0,0,0.08);
            background-color: #f5f5f5;
        }
        .action-buttons {
            display: flex;
            gap: 1rem;
            margin-top: 1.5rem;
            flex-wrap: wrap;
        }
        .download-btn {
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 0.5rem;
            padding: 0.75rem 1.5rem;
        }
        .image-box {
            background-color: rgba(111, 66, 193, 0.05);
            border-left: 3px solid var(--image-color);
            padding: 1rem;
            border-radius: 0 4px 4px 0;
            margin: 1.5rem 0;
        }
        @media (max-width: 768px) {
            .color-conversion-result {
                flex-direction: column;
            }
            .conversion-arrow {
                transform: rotate(90deg);
            }
            .action-buttons {
                flex-direction: column;
            }
            .download-btn {
                width: 100%;
            }
        }
        .quick-examples {
            display: flex;
            flex-wrap: wrap;
            gap: 0.75rem;
            margin: 1rem 0;
        }
        .example-chip {
            background-color: rgba(44, 125, 160, 0.1);
            border: 1px solid rgba(44, 125, 160, 0.2);
            border-radius: 20px;
            padding: 0.5rem 1rem;
            font-size: 0.9rem;
            color: var(--primary-color);
            cursor: pointer;
            transition: all 0.2s;
            display: flex;
            align-items: center;
        }
        .example-chip:hover {
            background-color: rgba(44, 125, 160, 0.2);
            transform: translateY(-2px);
        }
        .example-color {
            width: 20px;
            height: 20px;
            border-radius: 50%;
            margin-right: 0.5rem;
            border: 1px solid rgba(0,0,0,0.1);
        }