:root {
            --primary: #2563eb;
            --primary-dark: #1d4ed8;
            --secondary: #475569;
            --accent: #8b5cf6;
            --background: #f8fafc;
            --card-bg: #ffffff;
            --text: #1e293b;
            --text-light: #64748b;
            --border: #e2e8f0;
            --success: #10b981;
            --success-light: #ecfdf5;
            --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
            --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
            --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
            --radius: 8px;
            --transition: all 0.3s ease;
        }

        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        body {
            font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
            background-color: var(--background);
            color: var(--text);
            line-height: 1.6;
            padding: 0;
            margin: 0;
            min-height: 100vh;
        }

        .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
        }

        header {
            background: white;
            color: var(--text);
            padding: 40px 0;
            margin-bottom: 40px;
            box-shadow: var(--shadow);
        }

        header .container {
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            text-align: center;
        }

        h1 {
            font-size: 2.5rem;
            font-weight: 700;
            margin: 0;
            letter-spacing: -0.025em;
            margin-bottom: 8px;
            color: var(--primary);
        }

        h2 {
            font-size: 1.5rem;
            font-weight: 600;
            margin: 1.5rem 0 1rem 0;
            color: var(--primary);
        }

        h3 {
            font-size: 1.2rem;
            font-weight: 600;
            margin: 1.2rem 0 0.8rem 0;
            color: var(--secondary);
        }

        .header-desc {
            font-size: 1.1rem;
            max-width: 600px;
            opacity: 0.9;
            margin-top: 10px;
        }

        .card {
            background-color: var(--card-bg);
            border-radius: var(--radius);
            box-shadow: var(--shadow);
            margin-bottom: 30px;
            transition: var(--transition);
            border: 1px solid var(--border);
            overflow: hidden;
        }

        .card:hover {
            box-shadow: var(--shadow-lg);
            transform: translateY(-2px);
        }

        .card-header {
            padding: 20px 25px;
            border-bottom: 1px solid var(--border);
            background-color: rgba(245, 247, 250, 0.5);
        }

        .card-header h2 {
            margin: 0;
        }

        .card-body {
            padding: 25px;
        }

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

        label {
            display: block;
            margin-bottom: 8px;
            font-weight: 500;
            color: var(--text);
        }

        textarea, input {
            width: 100%;
            padding: 12px 15px;
            border: 1px solid var(--border);
            border-radius: var(--radius);
            font-size: 15px;
            font-family: inherit;
            color: var(--text);
            background-color: var(--card-bg);
            transition: var(--transition);
        }

        textarea {
            min-height: 120px;
            resize: vertical;
        }

        textarea:focus, input:focus, select:focus {
            outline: none;
            border-color: var(--primary);
            box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
        }

        select {
            padding: 12px 15px;
            border: 1px solid var(--border);
            border-radius: var(--radius);
            font-size: 15px;
            font-family: inherit;
            color: var(--text);
            width: 100%;
            max-width: 400px;
            background-color: var(--card-bg);
            appearance: none;
            background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' fill='%232563eb' viewBox='0 0 16 16'%3E%3Cpath d='M7.247 11.14 2.451 5.658C1.885 5.013 2.345 4 3.204 4h9.592a1 1 0 0 1 .753 1.659l-4.796 5.48a1 1 0 0 1-1.506 0z'/%3E%3C/svg%3E");
            background-repeat: no-repeat;
            background-position: right 15px center;
            padding-right: 45px;
            transition: var(--transition);
        }

        button {
            padding: 12px 24px;
            border: none;
            border-radius: var(--radius);
            background-color: var(--primary);
            color: white;
            font-size: 1rem;
            font-weight: 500;
            cursor: pointer;
            transition: var(--transition);
            display: inline-flex;
            align-items: center;
            justify-content: center;
            gap: 8px;
        }

        button:hover {
            background-color: var(--primary-dark);
            transform: translateY(-1px);
            box-shadow: var(--shadow);
        }

        button:active {
            transform: translateY(0);
        }

        button.secondary {
            background-color: #f1f5f9;
            color: var(--secondary);
            border: 1px solid var(--border);
        }

        button.secondary:hover {
            background-color: #e2e8f0;
        }

        .button-group {
            display: flex;
            gap: 12px;
            flex-wrap: wrap;
            margin-top: 20px;
        }

        .ratio-container {
            display: flex;
            align-items: center;
            gap: 12px;
            flex-wrap: wrap;
            margin-top: 15px;
        }

        .ratio-input {
            width: 80px;
            text-align: center;
        }

        .custom-ratio {
            padding: 20px;
            background-color: #f8fafc;
            border-radius: var(--radius);
            border: 1px solid var(--border);
            margin-top: 15px;
            animation: fadeIn 0.3s ease;
        }

        code {
            display: block;
            padding: 20px;
            background-color: #f1f5f9;
            border-radius: var(--radius);
            font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
            line-height: 1.5;
            font-size: 14px;
            color: #334155;
            overflow-x: auto;
            white-space: pre-wrap;
            word-break: break-all;
        }

        .success-message {
            color: var(--success);
            font-weight: 500;
            margin-left: 10px;
            opacity: 0;
            transition: opacity 0.5s ease;
        }

        .show {
            opacity: 1;
        }

        .preview-section {
            margin-top: 30px;
            padding-top: 30px;
            border-top: 1px solid var(--border);
        }

        .copy-container {
            display: flex;
            align-items: center;
            margin-top: 15px;
        }

        .result-item {
            margin-bottom: 25px;
        }

        /* Icons */
        .icon {
            display: inline-block;
            width: 20px;
            height: 20px;
            stroke-width: 0;
            stroke: currentColor;
            fill: currentColor;
        }

        /* Animations */
        @keyframes fadeIn {
            from { opacity: 0; transform: translateY(10px); }
            to { opacity: 1; transform: translateY(0); }
        }

        .fade-in {
            animation: fadeIn 0.5s ease;
        }

        /* Responsive */
        @media (max-width: 768px) {
            h1 {
                font-size: 2rem;
            }
            .button-group {
                flex-direction: column;
            }
            button {
                width: 100%;
            }
        }

        footer {
            text-align: center;
            margin-top: 60px;
            margin-bottom: 30px;
            color: var(--text-light);
            font-size: 0.9rem;
        }