/* 基础重置 - 兼容所有浏览器 */
        * {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
        }
        
        /* 清除浮动 - 兼容旧浏览器 */
        .clearfix::after {
            content: "";
            display: table;
            clear: both;
        }
        
        /* 简化渐变背景 - 为不支持linear-gradient的浏览器提供回退 */
        .gradient-bg {
            background: #2563eb; /* 主色作为回退 */
            background: linear-gradient(135deg, #2563eb 0%, #8b5cf6 100%);
        }
        
        /* 简化阴影效果 - 兼容旧浏览器 */
        .shadow-sm {
            box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
        }
        
        .shadow-md {
            box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
        }
        
        .shadow-lg {
            box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
        }
        
        /* 简化变换效果 - 为不支持transform的浏览器提供回退 */
        .hover\:-translate-y-1:hover {
            position: relative;
            top: -4px;
        }
        
        /* 简化透明度 - 兼容旧浏览器 */
        .opacity-90 {
            opacity: 0.9;
            filter: alpha(opacity=90); /* IE8及以下 */
        }
        
        .opacity-80 {
            opacity: 0.8;
            filter: alpha(opacity=80);
        }
        
        /* 简化过渡效果 */
        .transition-custom {
            transition: all 0.3s ease;
            -webkit-transition: all 0.3s ease;
            -moz-transition: all 0.3s ease;
            -o-transition: all 0.3s ease;
        }
        
        /* 简化flexbox布局 - 为旧浏览器提供回退 */
        .flex {
            display: -webkit-box;
            display: -ms-flexbox;
            display: flex;
        }
        
        .flex-col {
            -webkit-box-orient: vertical;
            -webkit-box-direction: normal;
                -ms-flex-direction: column;
                    flex-direction: column;
        }
        
        .flex-grow {
            -webkit-box-flex: 1;
                -ms-flex-positive: 1;
                    flex-grow: 1;
        }
        
        /* 简化grid布局 - 为不支持grid的浏览器提供flex回退 */
        .grid {
            display: -webkit-box;
            display: -ms-flexbox;
            display: flex;
            -ms-flex-wrap: wrap;
                flex-wrap: wrap;
        }
        
        .grid > * {
            -webkit-box-flex: 1;
                -ms-flex: 1 1 auto;
                    flex: 1 1 auto;
        }
        
        /* 为移动端菜单提供绝对定位回退 */
        #mobile-menu {
            position: absolute;
            left: 0;
            right: 0;
        }
        
        /* 简化clip-path回退 */
        .rounded-full {
            border-radius: 9999px;
        }
        
        .rounded-xl {
            border-radius: 12px;
        }
        
        /* 隐藏/显示类 */
        .hidden {
            display: none !important;
        }
        
        /* 固定定位兼容性 */
        .fixed {
            position: fixed;
            width: 100%;
        }
        
        /* 简化视口单位回退 */
        .min-h-screen {
            min-height: 100vh;
        }
        
        /* 简化clamp()函数回退 */
        .text-large {
            font-size: 2.5rem;
        }
        
        .text-medium {
            font-size: 1.5rem;
        }
        
        @media (max-width: 768px) {
            .text-large {
                font-size: 1.8rem;
            }
            
            .text-medium {
                font-size: 1.25rem;
            }
        }
        
        /* 简化backdrop-filter回退 */
        .backdrop-blur-sm {
            background-color: rgba(255, 255, 255, 0.15);
        }
        
        /* 主色调定义 */
        .text-primary {
            color: #2563eb;
        }
        
        .bg-primary {
            background-color: #2563eb;
        }
        
        .border-primary {
            border-color: #2563eb;
        }
        
        .text-secondary {
            color: #10b981;
        }
        
        .bg-secondary {
            background-color: #10b981;
        }
        
        .text-accent {
            color: #8b5cf6;
        }
        
        .bg-accent {
            background-color: #8b5cf6;
        }
        
        .text-neutral {
            color: #1e293b;
        }
        
        .bg-neutral {
            background-color: #1e293b;
        }
        
        .bg-light {
            background-color: #f8fafc;
        }
        
        /* 字体定义 */
        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            line-height: 1.6;
            color: #1e293b;
            background-color: #f8fafc;
        }
        
        /* 简化动画类 */
        .card-hover {
            transition: all 0.3s ease;
            -webkit-transition: all 0.3s ease;
            -moz-transition: all 0.3s ease;
            -o-transition: all 0.3s ease;
        }
        
        .card-hover:hover {
            box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
            position: relative;
            top: -4px;
        }
        
        /* 容器类 */
        .container {
            width: 100%;
            padding-right: 15px;
            padding-left: 15px;
            margin-right: auto;
            margin-left: auto;
        }
        
        @media (min-width: 640px) {
            .container {
                max-width: 640px;
            }
        }
        
        @media (min-width: 768px) {
            .container {
                max-width: 768px;
            }
        }
        
        @media (min-width: 1024px) {
            .container {
                max-width: 1024px;
            }
        }
        
        @media (min-width: 1280px) {
            .container {
                max-width: 1280px;
            }
        }
        
        /* 响应式显示/隐藏 */
        @media (max-width: 767px) {
            .md\:hidden {
                display: none !important;
            }
            
            .md\:block {
                display: block !important;
            }
        }
        
        @media (min-width: 768px) {
            .md\:flex {
                display: -webkit-box !important;
                display: -ms-flexbox !important;
                display: flex !important;
            }
        }
        
        /* 间距工具类 */
        .space-y-3 > * + * {
            margin-top: 12px;
        }
        
        .space-x-2 > * + * {
            margin-left: 8px;
        }
        
        .space-x-4 > * + * {
            margin-left: 16px;
        }
        
        .gap-4 {
            gap: 16px;
        }
        
        .gap-8 {
            gap: 32px;
        }
        
        /* 简化网格列 */
        .md\:grid-cols-2 {
            width: 50%;
        }
        
        .md\:grid-cols-3 {
            width: 33.333%;
        }
        
        .md\:grid-cols-4 {
            width: 25%;
        }
        
        /* 响应式调整 */
        @media (max-width: 767px) {
            .md\:grid-cols-2,
            .md\:grid-cols-3,
            .md\:grid-cols-4 {
                width: 100%;
            }
        }
        
        /* 填充和边距 */
        .p-4 {
            padding: 16px;
        }
        
        .p-6 {
            padding: 24px;
        }
        
        .p-8 {
            padding: 32px;
        }
        
        .py-12 {
            padding-top: 48px;
            padding-bottom: 48px;
        }
        
        .py-16 {
            padding-top: 64px;
            padding-bottom: 64px;
        }
        
        .py-20 {
            padding-top: 80px;
            padding-bottom: 80px;
        }
        
        .pt-20 {
            padding-top: 80px;
        }
        
        .mb-4 {
            margin-bottom: 16px;
        }
        
        .mb-6 {
            margin-bottom: 24px;
        }
        
        .mb-8 {
            margin-bottom: 32px;
        }
        
        .mb-10 {
            margin-bottom: 40px;
        }
        
        .mb-16 {
            margin-bottom: 64px;
        }
        
        .mx-auto {
            margin-left: auto;
            margin-right: auto;
        }
        
        /* 文本对齐 */
        .text-center {
            text-align: center;
        }
        
        .text-left {
            text-align: left;
        }
        
        /* 字体粗细 */
        .font-bold {
            font-weight: 700;
        }
        
        .font-semibold {
            font-weight: 600;
        }
        
        .font-medium {
            font-weight: 500;
        }
        
        /* 最大宽度 */
        .max-w-2xl {
            max-width: 42rem;
        }
        
        .max-w-3xl {
            max-width: 48rem;
        }
        
        .max-w-4xl {
            max-width: 56rem;
        }
        
        .max-w-5xl {
            max-width: 64rem;
        }
        
        /* 边框 */
        .border-2 {
            border-width: 2px;
            border-style: solid;
        }
        
        .border-t {
            border-top-width: 1px;
            border-top-style: solid;
        }
        
        /* 文本阴影简化 */
        .text-shadow {
            text-shadow: 0 2px 4px rgba(0,0,0,0.1);
        }
        
        /* 颜色辅助类 */
        .text-gray-400 {
            color: #9ca3af;
        }
        
        .text-gray-500 {
            color: #6b7280;
        }
        
        .text-gray-600 {
            color: #4b5563;
        }
        
        .bg-gray-50 {
            background-color: #f9fafb;
        }
        
        .bg-gray-100 {
            background-color: #f3f4f6;
        }
        
        .bg-gray-900 {
            background-color: #111827;
        }
        
        .bg-white {
            background-color: #ffffff;
        }
        
        .text-white {
            color: #ffffff;
        }
        
        .bg-blue-100 {
            background-color: #dbeafe;
        }
        
        .text-blue-500 {
            color: #3b82f6;
        }
        
        .bg-green-100 {
            background-color: #d1fae5;
        }
        
        .text-green-500 {
            color: #10b981;
        }
        
        .bg-purple-100 {
            background-color: #e9d5ff;
        }
        
        .text-purple-500 {
            color: #8b5cf6;
        }
        
        .bg-orange-100 {
            background-color: #ffedd5;
        }
        
        .text-orange-500 {
            color: #f97316;
        }
        
        .bg-yellow-400 {
            background-color: #fbbf24;
        }
        
        .text-yellow-400 {
            color: #fbbf24;
        }
        
        /* 宽度和高度 */
        .w-full {
            width: 100%;
        }
        
        .w-12 {
            width: 48px;
        }
        
        .w-14 {
            width: 56px;
        }
        
        .w-16 {
            width: 64px;
        }
        
        .w-24 {
            width: 96px;
        }
        
        .h-12 {
            height: 48px;
        }
        
        .h-14 {
            height: 56px;
        }
        
        .h-16 {
            height: 64px;
        }
        
        .h-24 {
            height: 96px;
        }
        
        /* 对象适应 */
        .object-cover {
            object-fit: cover;
        }
        
        /* 定位 */
        .relative {
            position: relative;
        }
        
        .absolute {
            position: absolute;
        }
        
        .z-10 {
            z-index: 10;
        }
        
        .z-20 {
            z-index: 20;
        }
        
        .z-50 {
            z-index: 50;
        }
        
        /* 光标 */
        .cursor-pointer {
            cursor: pointer;
        }
        
        /* 不透明度 */
        .opacity-0 {
            opacity: 0;
        }
        
        .opacity-100 {
            opacity: 1;
        }
        
        /* 可见性 */
        .invisible {
            visibility: hidden;
        }
        
        .visible {
            visibility: visible;
        }
        
        /* 长宽比容器简化 */
        .aspect-video {
            position: relative;
            padding-bottom: 56.25%; /* 16:9 */
            height: 0;
            overflow: hidden;
        }
        
        .aspect-video > * {
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
        }
        
        /* 简化translate变换 */
        .translate-y-0 {
            transform: translateY(0);
            -webkit-transform: translateY(0);
            -moz-transform: translateY(0);
            -ms-transform: translateY(0);
            -o-transform: translateY(0);
        }
        
        .translate-y-4 {
            transform: translateY(16px);
            -webkit-transform: translateY(16px);
            -moz-transform: translateY(16px);
            -ms-transform: translateY(16px);
            -o-transform: translateY(16px);
        }
        
        /* 简化按钮样式 */
        .btn-primary {
            display: inline-block;
            background-color: #2563eb;
            color: white;
            padding: 12px 32px;
            border-radius: 9999px;
            font-weight: 600;
            text-decoration: none;
            transition: all 0.3s ease;
        }
        
        .btn-primary:hover {
            background-color: #1d4ed8;
            box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
            position: relative;
            top: -2px;
        }
        
        .btn-outline-white {
            display: inline-block;
            border: 2px solid white;
            color: white;
            padding: 12px 32px;
            border-radius: 9999px;
            font-weight: 600;
            text-decoration: none;
            transition: all 0.3s ease;
        }
        
        .btn-outline-white:hover {
            background-color: rgba(255, 255, 255, 0.1);
        }