/* ========== CSS 变量 - 中国风配色 ========== */
        :root {
            --primary: #1677ff;        /* 中国红变体，更加现代 */
            --primary-dark: #0958d9;
            --primary-light: rgba(22, 119, 255, 0.1);
            --primary-lighter: rgba(22, 119, 255, 0.06);
            
            --secondary: #666666;       /* 中性灰 */
            --secondary-light: #999999;
            
            --success: #52c41a;         /* 青绿色 */
            --success-dark: #389e0d;
            --success-light: rgba(82, 196, 26, 0.1);
            
            --error: #ff4d4f;          /* 警示红 */
            --error-dark: #d9363e;
            --error-light: rgba(255, 77, 79, 0.1);
            
            --warning: #faad14;        /* 橙色 */
            --warning-dark: #d48806;
            
            --light: #fafafa;          /* 浅灰背景 */
            --light-2: #f5f5f5;
            --light-3: #f0f0f0;
            
            --dark: #262626;           /* 深灰文字 */
            --darker: #000000;
            
            --border: #d9d9d9;         /* 边框色 */
            --border-light: #f0f0f0;
            
            --radius: 8px;             /* 圆角大小 */
            --radius-sm: 6px;
            --radius-lg: 12px;
            
            --shadow: 0 3px 6px rgba(0, 0, 0, 0.05);
            --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.08);
            --shadow-hover: 0 12px 32px rgba(0, 0, 0, 0.12);
            
            --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        }
        
        /* ========== 重置样式 ========== */
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        
        html {
            scroll-behavior: smooth;
            font-size: 16px;
        }
        
        body {
            font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
            line-height: 1.5715;
            color: var(--dark);
            background: var(--light);
            min-height: 100vh;
            overflow-x: hidden;
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }
        
        a {
            text-decoration: none;
            color: inherit;
            transition: var(--transition);
        }
        
        ul, ol {
            list-style: none;
        }
        
        img {
            max-width: 100%;
            height: auto;
            display: block;
        }
        
        button, input, textarea, select {
            font-family: inherit;
            font-size: inherit;
            outline: none;
            border: none;
            background: none;
        }
        
        /* ========== 通用样式 ========== */
        .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
        }
        
        .section {
            padding: 80px 0;
        }
        
        .section-sm {
            padding: 60px 0;
        }
        
        .text-center {
            text-align: center;
        }
        
        .flex {
            display: flex;
        }
        
        .flex-col {
            flex-direction: column;
        }
        
        .items-center {
            align-items: center;
        }
        
        .justify-between {
            justify-content: space-between;
        }
        
        .justify-center {
            justify-content: center;
        }
        
        .gap-1 {
            gap: 8px;
        }
        
        .gap-2 {
            gap: 16px;
        }
        
        .gap-3 {
            gap: 24px;
        }
        
        .gap-4 {
            gap: 32px;
        }
        
        .mt-1 { margin-top: 8px; }
        .mt-2 { margin-top: 16px; }
        .mt-3 { margin-top: 24px; }
        .mt-4 { margin-top: 32px; }
        .mt-5 { margin-top: 40px; }
        
        .mb-1 { margin-bottom: 8px; }
        .mb-2 { margin-bottom: 16px; }
        .mb-3 { margin-bottom: 24px; }
        .mb-4 { margin-bottom: 32px; }
        
        /* ========== 导航栏 - 更简洁 ========== */
        .navbar {
            background: white;
            padding: 0;
            position: sticky;
            top: 0;
            z-index: 1000;
            box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
            border-bottom: 1px solid var(--border-light);
            height: 64px;
        }
        
        .nav-content {
            height: 100%;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        
        .logo {
            display: flex;
            align-items: center;
            gap: 12px;
        }
        
        .logo img {
            height: 36px;
            transition: var(--transition);
        }
        
        .logo img:hover {
            transform: scale(1.05);
        }
        
        .logo-text {
            font-size: 20px;
            font-weight: 600;
            color: var(--darker);
            background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
        }
        
        .nav-links {
            display: flex;
            gap: 32px;
            align-items: center;
        }
        
        .nav-link {
            color: var(--dark);
            font-weight: 500;
            font-size: 15px;
            padding: 8px 0;
            position: relative;
            transition: var(--transition);
            display: flex;
            align-items: center;
            gap: 8px;
        }
        
        .nav-link:hover {
            color: var(--primary);
        }
        
        .nav-link.active {
            color: var(--primary);
            font-weight: 600;
        }
        
        .nav-link.active::after {
            content: '';
            position: absolute;
            bottom: -1px;
            left: 0;
            width: 100%;
            height: 3px;
            background: var(--primary);
            border-radius: 3px 3px 0 0;
        }
        
        .nav-actions {
            display: flex;
            gap: 12px;
            align-items: center;
        }
        
        /* ========== 按钮样式 - 更精致 ========== */
        .btn {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            gap: 8px;
            padding: 8px 20px;
            border-radius: var(--radius);
            font-weight: 500;
            font-size: 15px;
            transition: var(--transition);
            cursor: pointer;
            border: 1px solid transparent;
            white-space: nowrap;
            height: 36px;
            line-height: 1;
        }
        
        .btn-sm {
            padding: 6px 16px;
            font-size: 14px;
            height: 32px;
        }
        
        .btn-lg {
            padding: 12px 28px;
            font-size: 16px;
            height: 44px;
            border-radius: var(--radius-lg);
        }
        
        .btn-block {
            width: 100%;
        }
        
        .btn-primary {
            background: var(--primary);
            color: white;
            border-color: var(--primary);
            box-shadow: 0 2px 4px rgba(22, 119, 255, 0.1);
        }
        
        .btn-primary:hover {
            background: var(--primary-dark);
            border-color: var(--primary-dark);
            transform: translateY(-2px);
            box-shadow: 0 4px 12px rgba(22, 119, 255, 0.2);
        }
        
        .btn-outline {
            background: white;
            color: var(--primary);
            border-color: var(--primary);
        }
        
        .btn-outline:hover {
            background: var(--primary);
            color: white;
            border-color: var(--primary);
            transform: translateY(-2px);
            box-shadow: var(--shadow);
        }
        
        .btn-success {
            background: var(--success);
            color: white;
            border-color: var(--success);
        }
        
        .btn-success:hover {
            background: var(--success-dark);
            border-color: var(--success-dark);
            transform: translateY(-2px);
        }
        
        .btn:disabled {
            opacity: 0.5;
            cursor: not-allowed;
            transform: none !important;
            box-shadow: none !important;
        }
        
        /* ========== 主内容区 ========== */
        .main-content {
            flex: 1;
            padding: 40px 0 0;
        }
        
        /* ========== 生成器卡片 - 卡片式设计 ========== */
        .generator-card {
            background: white;
            border-radius: var(--radius-lg);
            overflow: hidden;
            box-shadow: var(--shadow-lg);
            margin-bottom: 80px;
            border: 1px solid var(--border-light);
        }
        
        .generator-grid {
            display: grid;
            grid-template-columns: 1.2fr 0.8fr;
            min-height: 520px;
        }
        
        .generator-left {
            padding: 48px;
            display: flex;
            flex-direction: column;
            justify-content: center;
            background: linear-gradient(135deg, #fafafa 0%, #f5f5f5 100%);
            position: relative;
            overflow: hidden;
        }
        
        .generator-left::before {
            content: '';
            position: absolute;
            top: 0;
            right: 0;
            width: 120px;
            height: 120px;
            background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
            border-radius: 0 0 0 100%;
            opacity: 0.1;
        }
        
        .generator-right {
            padding: 48px;
            display: flex;
            flex-direction: column;
            background: white;
            border-left: 1px solid var(--border-light);
        }
        
        .generator-header {
            margin-bottom: 40px;
        }
        
        .generator-title {
            font-size: 28px;
            font-weight: 600;
            color: var(--darker);
            margin-bottom: 12px;
            line-height: 1.4;
        }
        
        .generator-subtitle {
            font-size: 16px;
            color: var(--secondary);
            line-height: 1.6;
        }
        
        /* ========== 表单样式 - 更符合中国审美 ========== */
        .form-group {
            margin-bottom: 28px;
        }
        
        .form-label {
            display: flex;
            align-items: center;
            gap: 8px;
            margin-bottom: 12px;
            font-weight: 500;
            color: var(--darker);
            font-size: 15px;
        }
        
        .form-label-icon {
            color: var(--primary);
            font-size: 16px;
        }
        
        .form-control {
            width: 100%;
            padding: 12px 16px;
            border: 1px solid var(--border);
            border-radius: var(--radius);
            font-size: 15px;
            transition: var(--transition);
            background: white;
            color: var(--dark);
            line-height: 1.5715;
        }
        
        .form-control:focus {
            border-color: var(--primary);
            box-shadow: 0 0 0 2px rgba(22, 119, 255, 0.1);
            outline: none;
        }
        
        .form-control:disabled {
            background: var(--light-3);
            color: var(--secondary-light);
            cursor: not-allowed;
        }
        
        /* ========== 自定义短链接输入框 - 中文风格 ========== */
        .custom-url-container {
            display: flex;
            align-items: stretch;
            width: 100%;
            border: 1px solid var(--border);
            border-radius: var(--radius);
            overflow: hidden;
            background: white;
            transition: var(--transition);
            height: 44px;
        }
        
        .custom-url-container:focus-within {
            border-color: var(--primary);
            box-shadow: 0 0 0 2px rgba(22, 119, 255, 0.1);
        }
        
        .url-prefix {
            display: flex;
            align-items: center;
            gap: 8px;
            padding: 0 16px;
            background: var(--light-3);
            font-weight: 500;
            color: var(--primary);
            font-size: 15px;
            white-space: nowrap;
            border-right: 1px solid var(--border);
            min-width: 140px;
        }
        
        .url-prefix-icon {
            color: var(--primary);
        }
        
        .custom-url-input {
            flex: 1;
            padding: 0 16px;
            font-size: 15px;
            background: transparent;
            min-width: 0;
            color: var(--dark);
        }
        
        .custom-url-input::placeholder {
            color: var(--secondary-light);
        }
        
        .form-text {
            display: block;
            margin-top: 8px;
            color: var(--secondary);
            font-size: 13px;
            display: flex;
            align-items: center;
            gap: 6px;
        }
        
        .form-text-icon {
            color: var(--primary);
        }
        
        /* ========== 消息提示 - 中文风格 ========== */
        .alert {
            padding: 12px 20px;
            border-radius: var(--radius);
            margin-bottom: 24px;
            font-weight: 500;
            display: flex;
            align-items: center;
            gap: 12px;
            animation: slideIn 0.3s ease;
            font-size: 14px;
            line-height: 1.5;
        }
        
        @keyframes slideIn {
            from {
                opacity: 0;
                transform: translateY(-10px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }
        
        .alert.success {
            background: var(--success-light);
            color: var(--success-dark);
            border: 1px solid rgba(82, 196, 26, 0.2);
            border-left: 4px solid var(--success);
        }
        
        .alert.error {
            background: var(--error-light);
            color: var(--error-dark);
            border: 1px solid rgba(255, 77, 79, 0.2);
            border-left: 4px solid var(--error);
        }
        
        /* ========== 结果卡片 - 更精致 ========== */
        .result-card {
            background: white;
            border-radius: var(--radius-lg);
            padding: 32px;
            border: 1px solid var(--border);
            animation: fadeIn 0.5s ease;
            box-shadow: var(--shadow);
        }
        
        @keyframes fadeIn {
            from { opacity: 0; transform: translateY(20px); }
            to { opacity: 1; transform: translateY(0); }
        }
        
        .result-header {
            display: flex;
            align-items: center;
            gap: 12px;
            margin-bottom: 24px;
        }
        
        .result-icon {
            width: 40px;
            height: 40px;
            background: var(--success-light);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            color: var(--success);
            font-size: 20px;
        }
        
        .result-title {
            font-size: 20px;
            font-weight: 600;
            color: var(--success-dark);
        }
        
        .short-url-display {
            display: flex;
            gap: 12px;
            margin-bottom: 24px;
        }
        
        .short-url-input {
            flex: 1;
            padding: 12px 16px;
            border: 1px solid var(--border);
            border-radius: var(--radius);
            background: white;
            font-family: 'Microsoft YaHei', 'PingFang SC', sans-serif;
            font-size: 15px;
            overflow: hidden;
            text-overflow: ellipsis;
            white-space: nowrap;
            color: var(--darker);
        }
        
        .action-buttons {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 12px;
            margin: 24px 0;
        }
        
        /* ========== 二维码区域 - 更美观 ========== */
        .qr-section {
            text-align: center;
            margin-top: 32px;
            padding-top: 32px;
            border-top: 1px solid var(--border);
        }
        
        .qr-title {
            font-weight: 600;
            margin-bottom: 20px;
            color: var(--darker);
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 10px;
            font-size: 18px;
        }
        
        .qr-code-container {
            position: relative;
            display: inline-block;
            margin: 16px auto;
            padding: 16px;
            background: white;
            border-radius: var(--radius);
            border: 1px solid var(--border);
            box-shadow: var(--shadow);
        }
        
        .qr-code {
            border-radius: var(--radius-sm);
            width: 200px;
            height: 200px;
            display: block;
        }
        
        .qr-tip {
            color: var(--secondary);
            margin-top: 20px;
            font-size: 14px;
            line-height: 1.6;
            max-width: 400px;
            margin-left: auto;
            margin-right: auto;
        }
        
        /* ========== 空状态 ========== */
        .result-placeholder {
            text-align: center;
            padding: 80px 20px;
            color: var(--secondary);
        }
        
        .placeholder-icon {
            font-size: 64px;
            color: var(--border);
            margin-bottom: 24px;
            opacity: 0.6;
        }
        
        .placeholder-title {
            font-size: 20px;
            font-weight: 500;
            margin-bottom: 12px;
            color: var(--secondary);
        }
        
        .placeholder-desc {
            font-size: 14px;
            color: var(--secondary-light);
            line-height: 1.6;
            max-width: 300px;
            margin: 0 auto;
        }
        
        /* ========== 功能介绍区 - 卡片式 ========== */
        .features-section {
            padding: 80px 0;
            background: linear-gradient(135deg, #fafafa 0%, #f5f5f5 100%);
            position: relative;
            overflow: hidden;
        }
        
        .features-section::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            height: 1px;
            background: linear-gradient(90deg, transparent, var(--border), transparent);
        }
        
        .section-header {
            text-align: center;
            margin-bottom: 60px;
            position: relative;
        }
        
        .section-title {
            font-size: 32px;
            font-weight: 600;
            color: var(--darker);
            margin-bottom: 16px;
            line-height: 1.3;
        }
        
        .section-subtitle {
            font-size: 16px;
            color: var(--secondary);
            max-width: 600px;
            margin: 0 auto;
            line-height: 1.6;
        }
        
        .features-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 24px;
            margin-top: 20px;
        }
        
        .feature-card {
            background: white;
            padding: 32px 24px;
            border-radius: var(--radius-lg);
            text-align: center;
            transition: var(--transition);
            border: 1px solid var(--border-light);
            height: 100%;
            position: relative;
            overflow: hidden;
        }
        
        .feature-card:hover {
            transform: translateY(-8px);
            box-shadow: var(--shadow-hover);
            border-color: var(--primary);
        }
        
        .feature-card::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            height: 3px;
            background: linear-gradient(90deg, var(--primary) 0%, var(--primary-dark) 100%);
            opacity: 0;
            transition: var(--transition);
        }
        
        .feature-card:hover::before {
            opacity: 1;
        }
        
        .feature-icon {
            width: 64px;
            height: 64px;
            margin: 0 auto 24px;
            background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 24px;
            color: white;
            transition: var(--transition);
        }
        
        .feature-card:hover .feature-icon {
            transform: scale(1.1);
        }
        
        .feature-title {
            font-weight: 600;
            margin-bottom: 12px;
            color: var(--darker);
            font-size: 18px;
            line-height: 1.4;
        }
        
        .feature-desc {
            font-size: 14px;
            color: var(--secondary);
            line-height: 1.6;
        }
        
        /* ========== 统计数据 ========== */
        .stats-section {
            background: linear-gradient(135deg, #fafafa 0%, #f5f5f5 100%);
            padding: 60px 0;
            position: relative;
        }
        
        .stats-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 40px;
            text-align: center;
        }
        
        .stat-item {
            padding: 32px 24px;
            background: white;
            border-radius: var(--radius-lg);
            border: 1px solid var(--border-light);
            transition: var(--transition);
        }
        
        .stat-item:hover {
            transform: translateY(-4px);
            box-shadow: var(--shadow-lg);
            border-color: var(--primary);
        }
        
        .stat-number {
            font-size: 48px;
            font-weight: 700;
            color: var(--primary);
            display: block;
            line-height: 1;
            margin-bottom: 12px;
            font-family: "Microsoft YaHei", sans-serif;
        }
        
        .stat-label {
            font-size: 16px;
            color: var(--secondary);
            font-weight: 500;
        }
        
        /* ========== 页脚 - 更简洁 ========== */
        .footer {
            background: var(--darker);
            color: white;
            padding: 0 0 30px;
            margin-top: 80px;
        }
        
        .footer-content {
            display: grid;
            grid-template-columns: 2fr 1fr 1fr;
            gap: 60px;
        }
        
        .footer-section h3 {
            color: white;
            margin-bottom: 24px;
            font-size: 18px;
            font-weight: 600;
        }
        
        .footer-section p {
            color: rgba(255, 255, 255, 0.7);
            line-height: 1.6;
            max-width: 400px;
            font-size: 14px;
        }
        
        .footer-links li {
            margin-bottom: 16px;
        }
        
        .footer-links a {
            color: rgba(255, 255, 255, 0.7);
            transition: var(--transition);
            display: flex;
            align-items: center;
            gap: 12px;
            font-size: 14px;
        }
        
        .footer-links a:hover {
            color: white;
            transform: translateX(4px);
        }
        
        .copyright {
            text-align: center;
            padding-top: 30px;
            margin-top: 60px;
            border-top: 1px solid rgba(255, 255, 255, 0.1);
            color: rgba(255, 255, 255, 0.5);
            font-size: 14px;
            line-height: 1.6;
        }
        
        .copyright a {
            color: rgba(255, 255, 255, 0.5);
            transition: var(--transition);
        }
        
        .copyright a:hover {
            color: white;
            text-decoration: underline;
        }
        
        /* ========== 响应式设计 ========== */
        @media (max-width: 1200px) {
            .container {
                max-width: 100%;
                padding: 0 24px;
            }
            
            .features-grid {
                gap: 20px;
            }
            
            .stats-grid {
                gap: 24px;
            }
        }
        
        @media (max-width: 992px) {
            .generator-grid {
                grid-template-columns: 1fr;
            }
            
            .generator-right {
                border-left: none;
                border-top: 1px solid var(--border-light);
            }
            
            .features-grid {
                grid-template-columns: repeat(2, 1fr);
            }
            
            .footer-content {
                grid-template-columns: repeat(2, 1fr);
                gap: 40px;
            }
            
            .section {
                padding: 60px 0;
            }
            
            .generator-left,
            .generator-right {
                padding: 40px 32px;
            }
        }
        
        @media (max-width: 768px) {
            .nav-links {
                display: none;
            }
            
            .nav-actions {
                display: flex;
            }
            
            .logo-text {
                display: none;
            }
            
            .generator-title {
                font-size: 24px;
            }
            
            .generator-subtitle {
                font-size: 15px;
            }
            
            .short-url-display {
                flex-direction: column;
            }
            
            .action-buttons {
                grid-template-columns: 1fr;
            }
            
            .custom-url-container {
                flex-direction: column;
                height: auto;
                border: none;
                background: transparent;
            }
            
            .url-prefix {
                width: 100%;
                justify-content: center;
                padding: 12px 16px;
                border: 1px solid var(--border);
                border-radius: var(--radius);
                margin-bottom: 8px;
                border-right: 1px solid var(--border);
                min-width: auto;
            }
            
            .custom-url-input {
                width: 100%;
                border: 1px solid var(--border);
                border-radius: var(--radius);
                padding: 12px 16px;
                height: 44px;
            }
            
            .features-grid {
                grid-template-columns: 1fr;
                gap: 20px;
            }
            
            .stats-grid {
                grid-template-columns: 1fr;
                gap: 20px;
            }
            
            .footer-content {
                grid-template-columns: 1fr;
                gap: 40px;
                text-align: center;
            }
            
            .footer-section p {
                max-width: 100%;
                margin: 0 auto;
            }
            
            .section-title {
                font-size: 28px;
            }
            
            .stat-number {
                font-size: 40px;
            }
        }
        
        @media (max-width: 480px) {
            .container {
                padding: 0 16px;
            }
            
            .generator-left,
            .generator-right {
                padding: 32px 24px;
            }
            
            .generator-title {
                font-size: 22px;
            }
            
            .nav-actions {
                gap: 8px;
            }
            
            .btn {
                padding: 8px 16px;
                font-size: 14px;
            }
            
            .section-title {
                font-size: 24px;
            }
            
            .stat-number {
                font-size: 36px;
            }
            
            .feature-card {
                padding: 24px 20px;
            }
        }
        
        /* ========== 工具类动画 ========== */
        .pulse {
            animation: pulse 2s infinite;
        }
        
        @keyframes pulse {
            0% { box-shadow: 0 0 0 0 rgba(22, 119, 255, 0.4); }
            70% { box-shadow: 0 0 0 10px rgba(22, 119, 255, 0); }
            100% { box-shadow: 0 0 0 0 rgba(22, 119, 255, 0); }
        }
        
        /* ========== 加载动画 ========== */
        .loading {
            display: inline-block;
            width: 16px;
            height: 16px;
            border: 2px solid rgba(255, 255, 255, 0.3);
            border-radius: 50%;
            border-top-color: white;
            animation: spin 0.8s linear infinite;
        }
        
        @keyframes spin {
            to { transform: rotate(360deg); }
        }
        
        /* ========== 滚动动画 ========== */
        .fade-in-up {
            opacity: 0;
            transform: translateY(20px);
            animation: fadeInUp 0.6s ease forwards;
        }
        
        @keyframes fadeInUp {
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }
        
        .delay-1 { animation-delay: 0.1s; }
        .delay-2 { animation-delay: 0.2s; }
        .delay-3 { animation-delay: 0.3s; }
        .delay-4 { animation-delay: 0.4s; }