/* =====================================================
   现代卡片式瀑布流网站CSS样式表
   布局方案: 卡片式瀑布流 (Masonry Grid)
   设计风格: 毛玻璃 + 渐变 + 圆角 + 微交互动效
   ===================================================== */

/* =====================================================
   第一部分：CSS变量定义
   ===================================================== */
:root {
    /* 主色调 */
    --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --secondary-gradient: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --accent-gradient: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    --dark-gradient: linear-gradient(180deg, #0f0f23 0%, #1a1a3e 100%);
    
    /* 毛玻璃颜色 */
    --glass-bg: rgba(255, 255, 255, 0.08);
    --glass-border: rgba(255, 255, 255, 0.15);
    --glass-shadow: rgba(0, 0, 0, 0.3);
    
    /* 品牌色彩 */
    --primary: #667eea;
    --primary-dark: #5a67d8;
    --secondary: #764ba2;
    --accent: #4facfe;
    --accent-light: #00f2fe;
    
    /* 背景与文字 */
    --bg-dark: #0f0f23;
    --bg-card: rgba(30, 30, 60, 0.6);
    --text-primary: #ffffff;
    --text-secondary: rgba(255, 255, 255, 0.7);
    --text-muted: rgba(255, 255, 255, 0.5);
    
    /* 间距系统 */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --spacing-3xl: 4rem;
    
    /* 圆角 */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --radius-full: 9999px;
    
    /* 阴影 */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.15);
    --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.25);
    --shadow-lg: 0 8px 40px rgba(0, 0, 0, 0.35);
    --shadow-glow: 0 0 30px rgba(102, 126, 234, 0.4);
    
    /* 过渡 */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);
    
    /* 字体 */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-display: 'Poppins', var(--font-primary);
    
    /* 布局 */
    --container-max: 1400px;
    --nav-height: 72px;
}

/* =====================================================
   第二部分：全局重置与基础样式
   ===================================================== */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-primary);
    background: var(--dark-gradient);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    overflow-x: hidden;
}

/* 背景装饰层 */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background:
        radial-gradient(ellipse at 20% 20%, rgba(102, 126, 234, 0.15) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 80%, rgba(118, 75, 162, 0.15) 0%, transparent 50%),
        radial-gradient(ellipse at 50% 50%, rgba(79, 172, 254, 0.08) 0%, transparent 70%);
    pointer-events: none;
    z-index: -1;
}

/* 链接基础样式 */
a {
    color: var(--accent);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--accent-light);
}

/* 图片基础样式 */
img {
    max-width: 100%;
    height: auto;
    display: block;
}

/* 列表基础样式 */
ul, ol {
    list-style: none;
}

/* 按钮基础样式 */
button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

/* 输入框基础样式 */
input, textarea, select {
    font-family: inherit;
    font-size: inherit;
}

/* =====================================================
   第三部分：容器与布局
   ===================================================== */
.container {
    width: 100%;
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

/* 主内容区域 */
.main-content {
    padding-top: var(--nav-height);
    min-height: 100vh;
}

/* =====================================================
   第四部分：瀑布流网格布局
   ===================================================== */
.masonry-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--spacing-lg);
    padding: var(--spacing-xl) 0;
}

.masonry-item {
    break-inside: avoid;
    margin-bottom: var(--spacing-lg);
}

/* 不同高度的瀑布流项目 */
.masonry-item--small .card {
    aspect-ratio: 1;
}

.masonry-item--medium .card {
    aspect-ratio: 4/5;
}

.masonry-item--large .card {
    aspect-ratio: 3/4;
}

.masonry-item--tall .card {
    aspect-ratio: 2/3;
}

/* =====================================================
   第五部分：毛玻璃卡片
   ===================================================== */
.card {
    position: relative;
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition:
        transform var(--transition-normal),
        box-shadow var(--transition-normal),
        border-color var(--transition-normal);
}

/* 卡片悬停效果 */
.card:hover {
    transform: translateY(-8px) scale(1.02);
    box-shadow: var(--shadow-lg), var(--shadow-glow);
    border-color: rgba(102, 126, 234, 0.4);
}

/* 卡片图片区域 */
.card__image {
    position: relative;
    width: 100%;
    height: 100%;
    overflow: hidden;
}

.card__image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition-slow);
}

.card:hover .card__image img {
    transform: scale(1.1);
}

/* 图片渐变叠加层 */
.card__image::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 60%;
    background: linear-gradient(to top, rgba(15, 15, 35, 0.9) 0%, transparent 100%);
    pointer-events: none;
}

/* 卡片内容区域 */
.card__content {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    padding: var(--spacing-lg);
    z-index: 1;
}

/* 卡片分类标签 */
.card__category {
    display: inline-block;
    padding: var(--spacing-xs) var(--spacing-sm);
    background: var(--primary-gradient);
    border-radius: var(--radius-full);
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: var(--spacing-sm);
}

/* 卡片标题 */
.card__title {
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 700;
    line-height: 1.3;
    margin-bottom: var(--spacing-sm);
    background: linear-gradient(135deg, #ffffff 0%, #e0e0e0 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* 卡片描述 */
.card__desc {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.5;
    margin-bottom: var(--spacing-md);
}

/* 卡片底部信息 */
.card__footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--glass-border);
}

.card__author {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.card__avatar {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    border: 2px solid var(--glass-border);
}

.card__author-name {
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text-primary);
}

.card__date {
    font-size: 0.8rem;
    color: var(--text-muted);
}

/* 卡片装饰元素 */
.card__decoration {
    position: absolute;
    top: var(--spacing-md);
    right: var(--spacing-md);
    width: 40px;
    height: 40px;
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transform: scale(0.8);
    transition:
        opacity var(--transition-normal),
        transform var(--transition-normal);
}

.card:hover .card__decoration {
    opacity: 1;
    transform: scale(1);
}

.card__decoration svg {
    width: 20px;
    height: 20px;
    stroke: var(--text-primary);
}

/* =====================================================
   第六部分：导航栏
   ===================================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--nav-height);
    background: rgba(15, 15, 35, 0.8);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--glass-border);
    z-index: 1000;
    transition: background var(--transition-normal);
}

.navbar:hover {
    background: rgba(15, 15, 35, 0.95);
}

.navbar__container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 100%;
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

/* Logo样式 */
.navbar__logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
}

.navbar__logo-icon {
    width: 40px;
    height: 40px;
    background: var(--primary-gradient);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
}

/* 导航链接 */
.navbar__menu {
    display: flex;
    align-items: center;
    gap: var(--spacing-xl);
}

.navbar__link {
    position: relative;
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--text-secondary);
    padding: var(--spacing-sm) 0;
    transition: color var(--transition-fast);
}

.navbar__link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent-gradient);
    border-radius: var(--radius-full);
    transition: width var(--transition-normal);
}

.navbar__link:hover,
.navbar__link--active {
    color: var(--text-primary);
}

.navbar__link:hover::after,
.navbar__link--active::after {
    width: 100%;
}

/* 导航栏按钮组 */
.navbar__actions {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

/* 汉堡菜单按钮 */
.navbar__toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: var(--spacing-sm);
}

.navbar__toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    border-radius: var(--radius-full);
    transition: var(--transition-fast);
}

/* =====================================================
   第七部分：按钮样式
   ===================================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-lg);
    font-size: 0.9rem;
    font-weight: 600;
    border-radius: var(--radius-full);
    transition:
        transform var(--transition-fast),
        box-shadow var(--transition-normal),
        background var(--transition-normal);
}

/* 主要按钮 */
.btn--primary {
    background: var(--primary-gradient);
    color: var(--text-primary);
    box-shadow: var(--shadow-sm);
}

.btn--primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md), var(--shadow-glow);
}

.btn--primary:active {
    transform: translateY(0);
}

/* 次要按钮 */
.btn--secondary {
    background: var(--glass-bg);
    color: var(--text-primary);
    border: 1px solid var(--glass-border);
    backdrop-filter: blur(10px);
}

.btn--secondary:hover {
    background: rgba(255, 255, 255, 0.15);
    border-color: rgba(255, 255, 255, 0.3);
}

/* 轮廓按钮 */
.btn--outline {
    background: transparent;
    color: var(--accent);
    border: 2px solid var(--accent);
}

.btn--outline:hover {
    background: var(--accent);
    color: var(--bg-dark);
}

/* 渐变文字按钮 */
.btn--gradient-text {
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    border: 1px solid var(--accent);
}

.btn--gradient-text:hover {
    background: var(--accent);
    -webkit-text-fill-color: var(--text-primary);
}

/* 大尺寸按钮 */
.btn--lg {
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: 1rem;
}

/* 小尺寸按钮 */
.btn--sm {
    padding: var(--spacing-xs) var(--spacing-md);
    font-size: 0.8rem;
}

/* 按钮图标 */
.btn__icon {
    width: 18px;
    height: 18px;
}

/* 悬浮时按钮图标动画 */
.btn:hover .btn__icon {
    transform: translateX(3px);
}

/* =====================================================
   第八部分：表单元素
   ===================================================== */
.form-group {
    margin-bottom: var(--spacing-lg);
}

.form-label {
    display: block;
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-sm);
}

/* 输入框 */
.form-input {
    width: 100%;
    padding: var(--spacing-md) var(--spacing-lg);
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 1rem;
    transition:
        border-color var(--transition-fast),
        box-shadow var(--transition-fast),
        background var(--transition-fast);
}

.form-input::placeholder {
    color: var(--text-muted);
}

.form-input:hover {
    border-color: rgba(255, 255, 255, 0.3);
    background: rgba(255, 255, 255, 0.12);
}

.form-input:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(79, 172, 254, 0.2);
    background: rgba(255, 255, 255, 0.15);
}

/* 文本域 */
.form-textarea {
    min-height: 120px;
    resize: vertical;
}

/* 选择框 */
.form-select {
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='24' height='24' viewBox='0 0 24 24' fill='none' stroke='%23ffffff' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right var(--spacing-md) center;
    background-size: 18px;
    padding-right: var(--spacing-2xl);
    cursor: pointer;
}

/* 复选框与单选框 */
.form-checkbox,
.form-radio {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    cursor: pointer;
}

.form-checkbox input,
.form-radio input {
    display: none;
}

.form-checkbox__box,
.form-radio__circle {
    width: 20px;
    height: 20px;
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    transition:
        background var(--transition-fast),
        border-color var(--transition-fast);
}

.form-radio__circle {
    border-radius: 50%;
}

.form-checkbox input:checked + .form-checkbox__box,
.form-radio input:checked + .form-radio__circle {
    background: var(--primary-gradient);
    border-color: transparent;
}

.form-checkbox__box svg,
.form-radio__circle::after {
    opacity: 0;
    transform: scale(0.5);
    transition:
        opacity var(--transition-fast),
        transform var(--transition-fast);
}

.form-checkbox input:checked + .form-checkbox__box svg,
.form-radio input:checked + .form-radio__circle::after {
    opacity: 1;
    transform: scale(1);
}

/* 搜索框 */
.search-box {
    position: relative;
    max-width: 400px;
}

.search-box__input {
    padding-left: var(--spacing-2xl);
}

.search-box__icon {
    position: absolute;
    left: var(--spacing-md);
    top: 50%;
    transform: translateY(-50%);
    width: 20px;
    height: 20px;
    stroke: var(--text-muted);
    pointer-events: none;
    transition: stroke var(--transition-fast);
}

.search-box:hover .search-box__icon {
    stroke: var(--text-secondary);
}

.search-box__input:focus + .search-box__icon {
    stroke: var(--accent);
}

/* =====================================================
   第九部分：Hero区域
   ===================================================== */
.hero {
    position: relative;
    padding: var(--spacing-3xl) 0;
    text-align: center;
    overflow: hidden;
}

/* 英雄区域装饰圆形 */
.hero::before,
.hero::after {
    content: '';
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.4;
    pointer-events: none;
}

.hero::before {
    width: 400px;
    height: 400px;
    background: var(--primary);
    top: -100px;
    left: -100px;
}

.hero::after {
    width: 300px;
    height: 300px;
    background: var(--accent);
    bottom: -50px;
    right: -50px;
}

.hero__content {
    position: relative;
    z-index: 1;
    max-width: 800px;
    margin: 0 auto;
}

.hero__badge {
    display: inline-block;
    padding: var(--spacing-xs) var(--spacing-md);
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-full);
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--accent);
    margin-bottom: var(--spacing-lg);
}

.hero__title {
    font-family: var(--font-display);
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 700;
    line-height: 1.1;
    margin-bottom: var(--spacing-lg);
    
    /* 渐变文字效果 */
    background: linear-gradient(
        135deg,
        #ffffff 0%,
        #e0e0e0 25%,
        var(--accent) 50%,
        #ffffff 75%,
        #e0e0e0 100%
    );
    background-size: 200% auto;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    
    animation: gradient-shift 8s ease infinite;
}

@keyframes gradient-shift {
    0%, 100% { background-position: 0% center; }
    50% { background-position: 100% center; }
}

.hero__subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xl);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.hero__actions {
    display: flex;
    justify-content: center;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

/* 几何装饰元素 */
.hero__decoration {
    position: absolute;
    pointer-events: none;
}

.hero__decoration--1 {
    top: 20%;
    left: 10%;
    width: 60px;
    height: 60px;
    border: 2px solid rgba(102, 126, 234, 0.3);
    border-radius: var(--radius-md);
    transform: rotate(45deg);
    animation: float 6s ease-in-out infinite;
}

.hero__decoration--2 {
    top: 60%;
    right: 15%;
    width: 40px;
    height: 40px;
    background: rgba(79, 172, 254, 0.2);
    border-radius: 50%;
    animation: float 8s ease-in-out infinite reverse;
}

.hero__decoration--3 {
    bottom: 20%;
    left: 20%;
    width: 80px;
    height: 80px;
    border: 3px solid rgba(118, 75, 162, 0.25);
    border-radius: var(--radius-lg);
    animation: rotate-slow 20s linear infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0) rotate(0deg); }
    50% { transform: translateY(-20px) rotate(5deg); }
}

@keyframes rotate-slow {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

/* =====================================================
   第十部分：特色区块
   ===================================================== */
.features {
    padding: var(--spacing-3xl) 0;
}

.features__grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-xl);
}

.feature-card {
    padding: var(--spacing-xl);
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    text-align: center;
    transition:
        transform var(--transition-normal),
        box-shadow var(--transition-normal),
        border-color var(--transition-normal);
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
    border-color: rgba(102, 126, 234, 0.3);
}

.feature-card__icon {
    width: 64px;
    height: 64px;
    margin: 0 auto var(--spacing-lg);
    background: var(--primary-gradient);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform var(--transition-normal);
}

.feature-card:hover .feature-card__icon {
    transform: scale(1.1) rotate(5deg);
}

.feature-card__icon svg {
    width: 32px;
    height: 32px;
    stroke: var(--text-primary);
}

.feature-card__title {
    font-family: var(--font-display);
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

.feature-card__desc {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* =====================================================
   第十一部分：页脚
   ===================================================== */
.footer {
    padding: var(--spacing-3xl) 0 var(--spacing-xl);
    background: rgba(10, 10, 20, 0.8);
    border-top: 1px solid var(--glass-border);
    margin-top: var(--spacing-3xl);
}

.footer__grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: var(--spacing-2xl);
    margin-bottom: var(--spacing-2xl);
}

.footer__brand {
    max-width: 300px;
}

.footer__logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--spacing-md);
}

.footer__desc {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

.footer__title {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-lg);
}

.footer__links {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.footer__link {
    font-size: 0.9rem;
    color: var(--text-secondary);
    transition: color var(--transition-fast);
}

.footer__link:hover {
    color: var(--accent);
}

.footer__social {
    display: flex;
    gap: var(--spacing-md);
}

.footer__social-link {
    width: 40px;
    height: 40px;
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    transition:
        background var(--transition-fast),
        border-color var(--transition-fast),
        transform var(--transition-fast);
}

.footer__social-link:hover {
    background: var(--primary-gradient);
    border-color: transparent;
    transform: translateY(-3px);
}

.footer__social-link svg {
    width: 20px;
    height: 20px;
    stroke: var(--text-primary);
}

.footer__bottom {
    padding-top: var(--spacing-xl);
    border-top: 1px solid var(--glass-border);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

.footer__copyright {
    font-size: 0.85rem;
    color: var(--text-muted);
}

.footer__legal {
    display: flex;
    gap: var(--spacing-lg);
}

.footer__legal-link {
    font-size: 0.85rem;
    color: var(--text-muted);
}

.footer__legal-link:hover {
    color: var(--text-secondary);
}

/* =====================================================
   第十二部分：加载动画
   ===================================================== */
.loading {
    display: flex;
    justify-content: center;
    align-items: center;
    padding: var(--spacing-2xl);
}

.loading__spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--glass-border);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* 骨架屏加载 */
.skeleton {
    background: linear-gradient(
        90deg,
        var(--glass-bg) 25%,
        rgba(255, 255, 255, 0.1) 50%,
        var(--glass-bg) 75%
    );
    background-size: 200% 100%;
    animation: shimmer 1.5s infinite;
    border-radius: var(--radius-md);
}

@keyframes shimmer {
    0% { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}

.skeleton--text {
    height: 1rem;
    margin-bottom: var(--spacing-sm);
}

.skeleton--title {
    height: 1.5rem;
    width: 70%;
    margin-bottom: var(--spacing-md);
}

.skeleton--image {
    aspect-ratio: 4/3;
}

/* =====================================================
   第十三部分：工具类
   ===================================================== */
.text-gradient {
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.text-accent {
    color: var(--accent);
}

.text-muted {
    color: var(--text-muted);
}

.text-center {
    text-align: center;
}

.mt-1 { margin-top: var(--spacing-xs); }
.mt-2 { margin-top: var(--spacing-sm); }
.mt-3 { margin-top: var(--spacing-md); }
.mt-4 { margin-top: var(--spacing-lg); }
.mt-5 { margin-top: var(--spacing-xl); }

.mb-1 { margin-bottom: var(--spacing-xs); }
.mb-2 { margin-bottom: var(--spacing-sm); }
.mb-3 { margin-bottom: var(--spacing-md); }
.mb-4 { margin-bottom: var(--spacing-lg); }
.mb-5 { margin-bottom: var(--spacing-xl); }

.py-1 { padding-top: var(--spacing-xs); padding-bottom: var(--spacing-xs); }
.py-2 { padding-top: var(--spacing-sm); padding-bottom: var(--spacing-sm); }
.py-3 { padding-top: var(--spacing-md); padding-bottom: var(--spacing-md); }
.py-4 { padding-top: var(--spacing-lg); padding-bottom: var(--spacing-lg); }
.py-5 { padding-top: var(--spacing-xl); padding-bottom: var(--spacing-xl); }

.hidden { display: none; }
.visible { display: block; }

.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.gap-1 { gap: var(--spacing-xs); }
.gap-2 { gap: var(--spacing-sm); }
.gap-3 { gap: var(--spacing-md); }
.gap-4 { gap: var(--spacing-lg); }
.gap-5 { gap: var(--spacing-xl); }

/* =====================================================
   第十四部分：响应式设计
   ===================================================== */

/* 超大屏幕 (>= 1400px) */
@media (max-width: 1399px) {
    .masonry-grid {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .footer__grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* 大屏幕平板 (>= 1024px) */
@media (max-width: 1023px) {
    :root {
        --nav-height: 64px;
    }
    
    .masonry-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: var(--spacing-md);
    }
    
    .features__grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .hero__title {
        font-size: clamp(2rem, 4vw, 3rem);
    }
    
    .navbar__menu {
        gap: var(--spacing-lg);
    }
}

/* 中等屏幕平板 (>= 768px) */
@media (max-width: 767px) {
    :root {
        --spacing-lg: 1rem;
        --spacing-xl: 1.5rem;
        --spacing-2xl: 2rem;
        --spacing-3xl: 3rem;
    }
    
    .masonry-grid {
        grid-template-columns: 1fr;
    }
    
    .masonry-item--small .card,
    .masonry-item--medium .card,
    .masonry-item--large .card,
    .masonry-item--tall .card {
        aspect-ratio: 4/3;
    }
    
    .features__grid {
        grid-template-columns: 1fr;
    }
    
    .footer__grid {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .footer__brand {
        max-width: 100%;
    }
    
    .footer__logo {
        justify-content: center;
    }
    
    .footer__social {
        justify-content: center;
    }
    
    .footer__bottom {
        flex-direction: column;
        text-align: center;
    }
    
    /* 移动端导航 */
    .navbar__menu {
        position: fixed;
        top: var(--nav-height);
        left: 0;
        right: 0;
        bottom: 0;
        background: rgba(15, 15, 35, 0.98);
        backdrop-filter: blur(20px);
        flex-direction: column;
        justify-content: flex-start;
        padding: var(--spacing-2xl);
        gap: var(--spacing-xl);
        transform: translateX(100%);
        transition: transform var(--transition-normal);
    }
    
    .navbar__menu.active {
        transform: translateX(0);
    }
    
    .navbar__link {
        font-size: 1.2rem;
    }
    
    .navbar__toggle {
        display: flex;
    }
    
    .navbar__toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }
    
    .navbar__toggle.active span:nth-child(2) {
        opacity: 0;
    }
    
    .navbar__toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(5px, -5px);
    }
    
    .hero {
        padding: var(--spacing-2xl) 0;
    }
    
    .hero__actions {
        flex-direction: column;
        align-items: center;
    }
    
    .hero__decoration {
        display: none;
    }
    
    .card__title {
        font-size: 1.25rem;
    }
    
    .card__desc {
        display: none;
    }
}

/* 小屏幕手机 (>= 480px) */
@media (max-width: 479px) {
    :root {
        --spacing-md: 0.75rem;
        --spacing-lg: 1rem;
        --radius-lg: 12px;
    }
    
    .container {
        padding: 0 var(--spacing-md);
    }
    
    .btn--lg {
        padding: var(--spacing-sm) var(--spacing-lg);
        font-size: 0.9rem;
    }
    
    .hero__title {
        font-size: 1.75rem;
    }
    
    .hero__subtitle {
        font-size: 1rem;
    }
    
    .feature-card {
        padding: var(--spacing-lg);
    }
    
    .feature-card__icon {
        width: 48px;
        height: 48px;
    }
    
    .feature-card__icon svg {
        width: 24px;
        height: 24px;
    }
}

/* 触摸设备优化 */
@media (hover: none) and (pointer: coarse) {
    .card:hover {
        transform: none;
    }
    
    .card:active {
        transform: scale(0.98);
        box-shadow: var(--shadow-md);
    }
    
    .btn:hover {
        transform: none;
    }
    
    .btn:active {
        transform: scale(0.95);
    }
    
    .navbar__link::after {
        display: none;
    }
    
    .navbar__link--active {
        color: var(--accent);
    }
}

/* 减少动画偏好 */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
    
    html {
        scroll-behavior: auto;
    }
}

/* 高对比度模式 */
@media (prefers-contrast: high) {
    :root {
        --glass-bg: rgba(255, 255, 255, 0.2);
        --glass-border: rgba(255, 255, 255, 0.4);
    }
    
    .card,
    .feature-card,
    .navbar {
        border-width: 2px;
    }
}

/* 打印样式 */
@media print {
    body::before,
    .hero__decoration,
    .card__decoration {
        display: none;
    }
    
    body {
        background: white;
        color: black;
    }
    
    .card,
    .feature-card,
    .navbar {
        background: white;
        border: 1px solid #ddd;
        box-shadow: none;
    }
    
    .btn--primary {
        background: #667eea;
    }
}
```