:root {
            --primary: #4361ee;
            --primary-dark: #3a56d4;
            --secondary: #7209b7;
            --accent: #f72585;
            --light: #f8f9fa;
            --dark: #212529;
            --success: #4cc9f0;
            --warning: #f8961e;
            --danger: #e63946;
            --gray: #6c757d;
            --gray-light: #e9ecef;
            --border-radius: 12px;
            --box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
            --transition: all 0.3s ease;
        }

        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }

        body {
            background: linear-gradient(135deg, #f5f7fa 0%, #e4edf5 100%);
            color: var(--dark);
            line-height: 1.6;
            min-height: 100vh;
            padding: 20px;
        }

        .container {
            max-width: 1400px;
            margin: 0 auto;
        }

        header {
            text-align: center;
            margin-bottom: 40px;
            padding: 30px 20px;
            background: white;
            border-radius: var(--border-radius);
            box-shadow: var(--box-shadow);
        }

        h1 {
            color: var(--primary);
            font-size: 2.5rem;
            margin-bottom: 10px;
        }

        .subtitle {
            color: var(--gray);
            font-size: 1.2rem;
            max-width: 700px;
            margin: 0 auto;
        }

        .main-content {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 30px;
            margin-bottom: 40px;
        }

        @media (max-width: 1024px) {
            .main-content {
                grid-template-columns: 1fr;
            }
        }

        .card {
            background: white;
            border-radius: var(--border-radius);
            box-shadow: var(--box-shadow);
            padding: 25px;
            transition: var(--transition);
        }

        .card:hover {
            transform: translateY(-5px);
            box-shadow: 0 15px 40px rgba(0, 0, 0, 0.12);
        }

        .card-title {
            font-size: 1.4rem;
            margin-bottom: 20px;
            color: var(--primary);
            display: flex;
            align-items: center;
            gap: 10px;
        }

        .card-title i {
            color: var(--secondary);
        }

        .input-group {
            margin-bottom: 20px;
        }

        textarea {
            width: 100%;
            min-height: 300px;
            padding: 15px;
            border: 2px solid var(--gray-light);
            border-radius: var(--border-radius);
            font-size: 1rem;
            resize: vertical;
            transition: var(--transition);
            font-family: 'Consolas', 'Monaco', monospace;
            line-height: 1.5;
        }

        textarea:focus {
            outline: none;
            border-color: var(--primary);
            box-shadow: 0 0 0 3px rgba(67, 97, 238, 0.2);
        }

        .btn {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            padding: 12px 24px;
            background: var(--primary);
            color: white;
            border: none;
            border-radius: var(--border-radius);
            font-size: 1rem;
            font-weight: 600;
            cursor: pointer;
            transition: var(--transition);
        }

        .btn:hover {
            background: var(--primary-dark);
            transform: translateY(-2px);
        }

        .btn-secondary {
            background: var(--secondary);
        }

        .btn-secondary:hover {
            background: #6411a3;
        }

        .btn-success {
            background: var(--success);
        }

        .btn-success:hover {
            background: #3ab3d6;
        }

        .btn-danger {
            background: var(--danger);
        }

        .btn-danger:hover {
            background: #d32f3a;
        }

        .btn-outline {
            background: transparent;
            border: 2px solid var(--primary);
            color: var(--primary);
        }

        .btn-outline:hover {
            background: var(--primary);
            color: white;
        }

        .btn-group {
            display: flex;
            gap: 10px;
            flex-wrap: wrap;
            margin-top: 15px;
        }

        .result-container {
            margin-top: 40px;
        }

        .result-area {
            background: white;
            border-radius: var(--border-radius);
            box-shadow: var(--box-shadow);
            padding: 25px;
            min-height: 400px;
            max-height: 600px;
            overflow-y: auto;
            font-family: 'Consolas', 'Monaco', monospace;
            line-height: 1.5;
            white-space: pre-wrap;
            word-wrap: break-word;
        }

        .diff-added {
            background-color: rgba(76, 201, 240, 0.2);
            padding: 2px 4px;
            border-radius: 4px;
            text-decoration: none;
        }

        .diff-removed {
            background-color: rgba(230, 57, 70, 0.2);
            padding: 2px 4px;
            border-radius: 4px;
            text-decoration: line-through;
        }

        .diff-unchanged {
            padding: 2px 4px;
        }

        .stats {
            display: flex;
            gap: 20px;
            margin-top: 20px;
            flex-wrap: wrap;
        }

        .stat-card {
            background: white;
            border-radius: var(--border-radius);
            box-shadow: var(--box-shadow);
            padding: 20px;
            text-align: center;
            flex: 1;
            min-width: 150px;
        }

        .stat-value {
            font-size: 2rem;
            font-weight: bold;
            color: var(--primary);
            margin-bottom: 5px;
        }

        .stat-label {
            color: var(--gray);
            font-size: 0.9rem;
        }

        .notification {
            position: fixed;
            bottom: 20px;
            right: 20px;
            padding: 15px 25px;
            background: var(--success);
            color: white;
            border-radius: var(--border-radius);
            box-shadow: var(--box-shadow);
            transform: translateY(100px);
            opacity: 0;
            transition: var(--transition);
            z-index: 1000;
        }

        .notification.show {
            transform: translateY(0);
            opacity: 1;
        }

        footer {
            text-align: center;
            padding: 30px 20px;
            color: var(--gray);
            font-size: 0.9rem;
            margin-top: 40px;
        }

        .feature-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 20px;
            margin-top: 40px;
        }

        .feature-card {
            background: white;
            border-radius: var(--border-radius);
            padding: 25px;
            text-align: center;
            box-shadow: var(--box-shadow);
            transition: var(--transition);
        }

        .feature-card:hover {
            transform: translateY(-5px);
        }

        .feature-icon {
            font-size: 2.5rem;
            color: var(--primary);
            margin-bottom: 15px;
        }

        .feature-title {
            font-size: 1.2rem;
            margin-bottom: 10px;
            color: var(--dark);
        }

        .feature-desc {
            color: var(--gray);
            font-size: 0.95rem;
        }

        .settings-panel {
            margin-top: 20px;
            padding-top: 20px;
            border-top: 1px solid var(--gray-light);
        }

        .setting-item {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 15px;
        }

        .switch {
            position: relative;
            display: inline-block;
            width: 50px;
            height: 24px;
        }

        .switch input {
            opacity: 0;
            width: 0;
            height: 0;
        }

        .slider {
            position: absolute;
            cursor: pointer;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background-color: #ccc;
            transition: .4s;
            border-radius: 24px;
        }

        .slider:before {
            position: absolute;
            content: "";
            height: 16px;
            width: 16px;
            left: 4px;
            bottom: 4px;
            background-color: white;
            transition: .4s;
            border-radius: 50%;
        }

        input:checked + .slider {
            background-color: var(--primary);
        }

        input:checked + .slider:before {
            transform: translateX(26px);
        }

        .badge {
            display: inline-block;
            padding: 3px 8px;
            background: var(--primary);
            color: white;
            border-radius: 20px;
            font-size: 0.75rem;
            font-weight: 600;
            margin-left: 5px;
        }

        .comparison-options {
            display: flex;
            gap: 10px;
            margin-top: 15px;
            flex-wrap: wrap;
        }

        .option-group {
            display: flex;
            gap: 10px;
            align-items: center;
        }

        select {
            padding: 10px 15px;
            border: 2px solid var(--gray-light);
            border-radius: var(--border-radius);
            font-size: 1rem;
            background: white;
            transition: var(--transition);
        }

        select:focus {
            outline: none;
            border-color: var(--primary);
        }

        .file-upload {
            display: none;
        }

        .file-upload-label {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            padding: 10px 20px;
            background: var(--gray-light);
            color: var(--dark);
            border-radius: var(--border-radius);
            cursor: pointer;
            transition: var(--transition);
        }

        .file-upload-label:hover {
            background: var(--gray);
            color: white;
        }

        .empty-state {
            text-align: center;
            padding: 40px 20px;
            color: var(--gray);
        }

        .empty-state i {
            font-size: 3rem;
            margin-bottom: 15px;
            color: var(--gray-light);
        }

        .legend {
            display: flex;
            gap: 15px;
            margin-top: 15px;
            flex-wrap: wrap;
        }

        .legend-item {
            display: flex;
            align-items: center;
            gap: 5px;
            font-size: 0.9rem;
        }

        .legend-color {
            width: 20px;
            height: 20px;
            border-radius: 4px;
        }

        .legend-added {
            background-color: rgba(76, 201, 240, 0.2);
        }

        .legend-removed {
            background-color: rgba(230, 57, 70, 0.2);
        }