/* 完整优化版CSS文件 - 增强粒子效果，增强性能和可维护性 */

/* ============ CSS变量系统 ============ */
:root {
    /* 主色系 - 科技蓝主题 */
    --primary: #0066CC;
    --primary-dark: #0052A3;
    --primary-light: #3399FF;
    --accent: #00A8FF;
    
    /* 副色系 */
    --secondary: #222222;
    --secondary-light: #444444;
    
    /* 背景色 */
    --bg: #FFFFFF;
    --bg-light: #F5F7FA;
    --bg-dark: #1A1A1A;
    
    /* 文字色 */
    --text: #333333;
    --text-light: #666666;
    --text-white: #FFFFFF;
    
    /* 边框色 */
    --border: #E6E6E6;
    
    /* 状态色 */
    --success: #34C759;
    --warning: #FF9500;
    --error: #FF3B30;
    
    /* 阴影 */
    --shadow: 0 4px 12px rgba(0, 102, 204, 0.1);
    --shadow-lg: 0 10px 30px rgba(0, 102, 204, 0.15);
    
    /* 圆角 */
    --radius: 12px;
    --radius-sm: 6px;
    --radius-pill: 50px;
    
    /* 过渡动画 */
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    
    /* 间距 */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --spacing-3xl: 4rem;
    
    /* 层叠上下文 */
    --z-background: -9999;
    --z-base: 1;
    --z-dropdown: 1000;
    --z-tooltip: 1001;
    --z-modal: 1002;
}

/* ============ 重置和基础样式 ============ */
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    -webkit-tap-highlight-color: transparent;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Noto Sans SC', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--bg-light);
    color: var(--text);
    line-height: 1.6;
    position: relative;
    overflow-x: hidden;
    text-rendering: optimizeLegibility;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    min-height: 100vh;
}

/* 平滑滚动容器 */
.smooth-scroll {
    scroll-behavior: smooth;
}

/* ============ 增强的背景动态效果 ============ */
.background-effects {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: var(--z-background);
    pointer-events: none;
    overflow: hidden;
    isolation: isolate;
}

/* 1. 增强的全局流动粒子背景 */
.global-particles {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    will-change: transform;
    transform: translateZ(0);
    backface-visibility: hidden;
}

.global-particle {
    position: absolute;
    border-radius: 50%;
    animation: floatParticle linear infinite;
    filter: blur(0.5px);
    transition: all 0.5s ease;
    z-index: var(--z-background);
}

@keyframes floatParticle {
    0% {
        transform: translateY(100vh) translateX(0) rotate(0deg);
        opacity: 0;
    }
    10% {
        opacity: 0.8;
    }
    90% {
        opacity: 0.8;
    }
    100% {
        transform: translateY(-100px) translateX(var(--move-x, 0)) rotate(360deg);
        opacity: 0;
    }
}

/* 2. 增强的动态波浪背景 */
.wave-container {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 30vh;
    overflow: hidden;
    opacity: 0.9;
}

.wave {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 200%;
    height: 100%;
    background: linear-gradient(transparent, rgba(0, 102, 204, 0.15));
    border-radius: 50% 50% 0 0;
    animation: waveMove 25s linear infinite;
    animation-play-state: running;
}

.wave:nth-child(2) {
    animation-delay: -5s;
    opacity: 0.4;
    height: 80%;
}

.wave:nth-child(3) {
    animation-delay: -10s;
    opacity: 0.2;
    height: 60%;
}

@keyframes waveMove {
    0% {
        transform: translateX(0) translateY(0);
    }
    50% {
        transform: translateX(-25%) translateY(10px);
    }
    100% {
        transform: translateX(-50%) translateY(0);
    }
}

/* ============ 容器和布局 ============ */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

.container-fluid {
    width: 100%;
    padding: 0 var(--spacing-lg);
}

/* ============ 英雄区域 ============ */
.hero {
    padding: clamp(4rem, 10vw, 8rem) 0 clamp(4rem, 8vw, 6rem);
    background: linear-gradient(135deg, #F0F7FF 0%, #E6F2FF 100%);
    position: relative;
    overflow: hidden;
    margin-top: 0;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    right: 0;
    width: min(50%, 600px);
    height: 100%;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><path fill="%230066CC" opacity="0.05" d="M0,0 L100,0 L100,100 Z"/></svg>');
    background-size: cover;
    opacity: 0.8;
}

.hero-content {
    max-width: 800px;
    position: relative;
    z-index: 2;
}

.hero-title {
    font-size: clamp(2rem, 5vw, 3.5rem);
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: var(--spacing-lg);
    background: linear-gradient(135deg, var(--primary), var(--accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.02em;
}

.hero-subtitle {
    font-size: clamp(1rem, 2.5vw, 1.25rem);
    color: var(--text-light);
    margin-bottom: var(--spacing-2xl);
    line-height: 1.7;
    max-width: 600px;
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
    margin-bottom: var(--spacing-2xl);
}

/* ============ 按钮样式 ============ */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: 0.875rem 1.75rem;
    border-radius: var(--radius-pill);
    font-weight: 600;
    font-size: 1rem;
    text-decoration: none;
    transition: var(--transition);
    border: 2px solid transparent;
    cursor: pointer;
    position: relative;
    overflow: hidden;
    white-space: nowrap;
    user-select: none;
    font-family: inherit;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--accent));
    color: var(--text-white);
    border: none;
    box-shadow: var(--shadow);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.btn-primary::after {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
    transition: left 0.7s ease;
}

.btn-primary:hover::after {
    left: 100%;
}

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

.btn-secondary:hover {
    background: var(--primary);
    color: var(--text-white);
    transform: translateY(-3px);
    box-shadow: var(--shadow);
}

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
}

.btn-lg {
    padding: 1rem 2rem;
    font-size: 1.125rem;
}

/* ============ 英雄特性网格 ============ */
.hero-features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-xl);
    margin-top: var(--spacing-3xl);
    padding-top: var(--spacing-2xl);
    border-top: 1px solid rgba(0, 102, 204, 0.1);
}

.feature-item {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-lg);
    padding: var(--spacing-xl);
    background: var(--bg);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.feature-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.feature-icon {
    width: 64px;
    height: 64px;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-white);
    font-size: 1.75rem;
    flex-shrink: 0;
    transition: var(--transition);
}

.feature-item:hover .feature-icon {
    transform: rotate(10deg) scale(1.1);
}

.feature-text h4 {
    font-size: 1.2rem;
    margin-bottom: var(--spacing-sm);
    color: var(--text);
    font-weight: 700;
}

.feature-text p {
    color: var(--text-light);
    font-size: 0.95rem;
    line-height: 1.6;
}

/* ============ 通用部分样式 ============ */
.section {
    padding: clamp(3rem, 8vw, 6rem) 0;
}

.section-title {
    text-align: center;
    margin-bottom: var(--spacing-3xl);
}

.title {
    font-size: clamp(1.75rem, 4vw, 2.5rem);
    font-weight: 800;
    margin-bottom: var(--spacing-md);
    background: linear-gradient(135deg, var(--primary), var(--accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    display: inline-block;
    letter-spacing: -0.02em;
}

.subtitle {
    color: var(--text-light);
    font-size: clamp(1rem, 2vw, 1.1rem);
    max-width: 600px;
    margin: 0 auto;
    line-height: 1.7;
}

/* ============ 服务网格 ============ */
.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-xl);
}

.service-card {
    background: var(--bg);
    border-radius: var(--radius);
    padding: var(--spacing-2xl) var(--spacing-xl);
    box-shadow: var(--shadow);
    transition: var(--transition);
    border: 1px solid transparent;
    text-align: center;
    position: relative;
    overflow: hidden;
    animation: fadeInUp 0.6s ease forwards;
    opacity: 0;
}

.service-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary);
}

.service-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto var(--spacing-lg);
    color: var(--text-white);
    font-size: 2rem;
    transition: var(--transition);
}

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

.service-card h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-md);
    color: var(--text);
    font-weight: 700;
}

.service-card p {
    color: var(--text-light);
    line-height: 1.6;
    font-size: 1rem;
}

/* ============ 技术栈网格 ============ */
.tech-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: var(--spacing-xl);
}

.tech-item {
    background: var(--bg);
    border-radius: var(--radius);
    padding: var(--spacing-xl);
    text-align: center;
    box-shadow: var(--shadow);
    transition: var(--transition);
    border: 1px solid transparent;
    animation: fadeInUp 0.6s ease forwards;
    opacity: 0;
}

.tech-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary);
}

.tech-icon {
    font-size: 3rem;
    color: var(--primary);
    margin-bottom: var(--spacing-md);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 80px;
    height: 80px;
    background: rgba(0, 102, 204, 0.1);
    border-radius: 50%;
    transition: var(--transition);
}

.tech-item:hover .tech-icon {
    transform: scale(1.1);
    background: rgba(0, 102, 204, 0.2);
}

.tech-item h4 {
    font-size: 1.1rem;
    margin-bottom: var(--spacing-sm);
    color: var(--text);
    font-weight: 600;
}

.tech-item p {
    color: var(--text-light);
    font-size: 0.9rem;
}

/* ============ 关于我们 ============ */
.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: clamp(2rem, 5vw, 4rem);
    align-items: center;
    margin-bottom: var(--spacing-3xl);
}

.about-image {
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
}

.image-placeholder {
    height: min(400px, 60vw);
    background: linear-gradient(135deg, var(--primary), var(--accent));
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-white);
    font-size: clamp(3rem, 6vw, 5rem);
    position: relative;
    overflow: hidden;
}

.image-placeholder::after {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(45deg, transparent 30%, rgba(255,255,255,0.1) 50%, transparent 70%);
    animation: shimmer 3s infinite;
}

@keyframes shimmer {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}

.about-text h3 {
    font-size: clamp(1.5rem, 3vw, 2rem);
    margin-bottom: var(--spacing-lg);
    color: var(--text);
    font-weight: 700;
}

.about-text p {
    color: var(--text-light);
    line-height: 1.7;
    margin-bottom: var(--spacing-lg);
    font-size: 1.05rem;
}

.stats {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-xl);
    margin-top: var(--spacing-2xl);
}

.stat-item {
    text-align: center;
    padding: var(--spacing-lg);
    background: var(--bg);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.stat-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.stat-number {
    font-size: clamp(2rem, 4vw, 2.5rem);
    font-weight: 800;
    color: var(--primary);
    display: block;
    line-height: 1;
    margin-bottom: var(--spacing-sm);
}

.stat-label {
    color: var(--text-light);
    font-size: 0.95rem;
    font-weight: 500;
}

.team-features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-xl);
}

.team-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
    padding: var(--spacing-xl);
    background: var(--bg);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    transition: var(--transition);
    animation: fadeInUp 0.6s ease forwards;
    opacity: 0;
}

.team-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
    background: linear-gradient(135deg, var(--primary), var(--accent));
    color: var(--text-white);
}

.team-item:hover .team-icon {
    background: var(--text-white);
    color: var(--primary);
}

.team-item:hover .team-content h4,
.team-item:hover .team-content p {
    color: var(--text-white);
}

.team-icon {
    width: 64px;
    height: 64px;
    background: var(--primary);
    color: var(--text-white);
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.75rem;
    flex-shrink: 0;
    transition: var(--transition);
}

.team-content h4 {
    font-size: 1.2rem;
    margin-bottom: var(--spacing-sm);
    color: var(--text);
    font-weight: 700;
    transition: var(--transition);
}

.team-content p {
    color: var(--text-light);
    font-size: 0.95rem;
    line-height: 1.6;
    transition: var(--transition);
}

/* ============ 页脚 ============ */
.footer {
    background: var(--bg-dark);
    color: var(--text-white);
    padding: var(--spacing-3xl) 0 var(--spacing-xl);
    position: relative;
    overflow: hidden;
}

.footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, var(--primary), var(--accent));
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: clamp(2rem, 4vw, 3rem);
    margin-bottom: var(--spacing-2xl);
}

.footer-about {
    padding-right: var(--spacing-xl);
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 1.75rem;
    font-weight: 800;
    margin-bottom: var(--spacing-lg);
    color: var(--text-white);
}

.footer-about p {
    color: rgba(255, 255, 255, 0.7);
    margin-bottom: var(--spacing-xl);
    line-height: 1.7;
    font-size: 1rem;
}

.footer-links h4 {
    font-size: 1.2rem;
    margin-bottom: var(--spacing-lg);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    color: var(--text-white);
    font-weight: 700;
}

.footer-links ul {
    list-style: none;
    padding: 0;
}

.footer-links li {
    margin-bottom: var(--spacing-sm);
}

.footer-links a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-xs) 0;
    font-size: 0.95rem;
}

.footer-links a:hover {
    color: var(--text-white);
    padding-left: var(--spacing-sm);
    transform: translateX(5px);
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: var(--spacing-xl);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.5);
    font-size: 0.875rem;
    position: relative;
}

.footer-legal a {
    color: rgba(255, 255, 255, 0.5);
    text-decoration: none;
    margin-left: var(--spacing-xl);
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.footer-legal a:hover {
    color: var(--text-white);
}

/* ============ 回到顶部按钮 ============ */
.back-to-top {
    position: fixed;
    bottom: var(--spacing-xl);
    right: var(--spacing-xl);
    width: 56px;
    height: 56px;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    color: var(--text-white);
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    z-index: var(--z-tooltip);
    box-shadow: var(--shadow);
    transform: translateY(20px);
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    transform: translateY(-5px) scale(1.05);
    box-shadow: var(--shadow-lg);
}

/* ============ Logo样式 ============ */
.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-xl);
}

.logo-icon {
    width: 60px;
    height: 60px;
    background: transparent;
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-white);
    font-size: 1.25rem;
    transition: var(--transition);
    overflow: hidden;
}

.logo:hover .logo-icon img {
    transform: scale(1.05);
}

.logo-icon img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    border-radius: var(--radius-sm);
    transition: var(--transition);
}

.logo-text {
    font-size: 1.75rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* ============ 用户相关样式 ============ */
.user-menu {
    position: fixed;
    top: var(--spacing-lg);
    right: var(--spacing-lg);
    z-index: var(--z-dropdown);
}

.auth-buttons {
    display: flex;
    gap: var(--spacing-sm);
    animation: fadeIn 0.5s ease;
}

.btn-login, .btn-register {
    padding: 0.6rem 1.25rem;
    border-radius: var(--radius-pill);
    font-weight: 600;
    font-size: 0.9rem;
    text-decoration: none;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    border: 2px solid transparent;
    font-family: 'Noto Sans SC', sans-serif;
}

.btn-login {
    background: transparent;
    color: var(--primary);
    border-color: var(--primary);
}

.btn-login:hover {
    background: var(--primary);
    color: var(--text-white);
    transform: translateY(-3px);
    box-shadow: var(--shadow);
}

.btn-register {
    background: linear-gradient(135deg, var(--primary), var(--accent));
    color: var(--text-white);
}

.btn-register:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.user-profile {
    position: relative;
    animation: fadeIn 0.5s ease;
}

.user-avatar {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    color: var(--text-white);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    border: 2px solid var(--bg);
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.user-avatar:hover {
    transform: scale(1.05) rotate(5deg);
    box-shadow: var(--shadow-lg);
}

.dropdown-menu {
    position: absolute;
    top: 60px;
    right: 0;
    background: var(--bg);
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
    min-width: 220px;
    display: none;
    overflow: hidden;
    z-index: var(--z-tooltip);
    animation: dropdownFadeIn 0.3s ease;
    border: 1px solid var(--border);
}

.dropdown-menu.show {
    display: block;
}

.dropdown-header {
    padding: var(--spacing-lg);
    background: linear-gradient(135deg, var(--primary), var(--accent));
    color: var(--text-white);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.user-avatar-small {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.2);
    color: var(--text-white);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1rem;
    font-weight: 600;
}

.dropdown-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: 0.875rem var(--spacing-lg);
    color: var(--text);
    text-decoration: none;
    transition: var(--transition);
    border-bottom: 1px solid var(--border);
    font-size: 0.95rem;
}

.dropdown-item:hover {
    background: var(--bg-light);
    color: var(--primary);
    padding-left: 1.5rem;
}

.dropdown-item:last-child {
    border-bottom: none;
    color: var(--error);
}

.dropdown-item:last-child:hover {
    background: rgba(255, 59, 48, 0.1);
}

/* ============ 动画关键帧 ============ */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes dropdownFadeIn {
    from {
        opacity: 0;
        transform: translateY(-20px) scale(0.95);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* ============ 服务卡片动画延迟 ============ */
.service-card:nth-child(1) { animation-delay: 0.1s; }
.service-card:nth-child(2) { animation-delay: 0.2s; }
.service-card:nth-child(3) { animation-delay: 0.3s; }
.service-card:nth-child(4) { animation-delay: 0.4s; }
.service-card:nth-child(5) { animation-delay: 0.5s; }
.service-card:nth-child(6) { animation-delay: 0.6s; }

.tech-item:nth-child(1) { animation-delay: 0.1s; }
.tech-item:nth-child(2) { animation-delay: 0.2s; }
.tech-item:nth-child(3) { animation-delay: 0.3s; }
.tech-item:nth-child(4) { animation-delay: 0.4s; }

.team-item:nth-child(1) { animation-delay: 0.1s; }
.team-item:nth-child(2) { animation-delay: 0.2s; }
.team-item:nth-child(3) { animation-delay: 0.3s; }
.team-item:nth-child(4) { animation-delay: 0.4s; }

/* ============ 滚动条美化 ============ */
::-webkit-scrollbar {
    width: 10px;
    height: 10px;
}

::-webkit-scrollbar-track {
    background: rgba(0, 102, 204, 0.05);
    border-radius: var(--radius-sm);
}

::-webkit-scrollbar-thumb {
    background: var(--primary);
    border-radius: var(--radius-sm);
    border: 2px solid transparent;
    background-clip: padding-box;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--primary-dark);
}

/* ============ 工具类 ============ */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.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); }

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

/* ============ 暗色模式支持 ============ */
@media (prefers-color-scheme: dark) {
    :root {
        --bg: #0a0a0a;
        --bg-light: #1a1a1a;
        --text: #ffffff;
        --text-light: #b0b0b0;
        --border: #333333;
    }
    
    .hero {
        background: linear-gradient(135deg, #0a1929 0%, #0a0a0a 100%);
    }
    
    .global-particle {
        background: var(--primary-light);
        box-shadow: 0 0 15px rgba(51, 153, 255, 0.5);
    }
    
    .wave {
        background: linear-gradient(transparent, rgba(0, 102, 204, 0.25));
    }
    
    .dropdown-menu {
        background: var(--bg-dark);
        border-color: rgba(255, 255, 255, 0.1);
    }
    
    .dropdown-item {
        color: var(--text-white);
        border-color: rgba(255, 255, 255, 0.1);
    }
    
    .dropdown-item:hover {
        background: rgba(255, 255, 255, 0.1);
    }
    
    .feature-item,
    .service-card,
    .tech-item,
    .stat-item,
    .team-item {
        background: rgba(255, 255, 255, 0.05);
        border-color: rgba(255, 255, 255, 0.1);
    }
}

/* ============ 移动端优化 ============ */
@media (max-width: 768px) {
    body {
        font-size: 15px;
    }
    
    .background-effects {
        opacity: 0.8;
    }
    
    .global-particle {
        width: 3px !important;
        height: 3px !important;
    }
    
    .wave {
        height: 20vh;
    }
    
    .hero {
        padding: var(--spacing-3xl) 0 var(--spacing-2xl);
    }
    
    .hero-buttons {
        flex-direction: column;
        width: 100%;
    }
    
    .hero-buttons .btn {
        width: 100%;
        max-width: 300px;
        justify-content: center;
    }
    
    .about-content {
        grid-template-columns: 1fr;
        gap: var(--spacing-2xl);
    }
    
    .stats {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }
    
    .footer-bottom {
        flex-direction: column;
        gap: var(--spacing-md);
        text-align: center;
    }
    
    .footer-legal a {
        margin: 0 var(--spacing-sm);
    }
    
    .user-menu {
        top: var(--spacing-md);
        right: var(--spacing-md);
    }
    
    .auth-buttons {
        gap: var(--spacing-xs);
    }
    
    .btn-login, .btn-register {
        padding: 0.5rem 1rem;
        font-size: 0.85rem;
    }
    
    .user-avatar {
        width: 44px;
        height: 44px;
        font-size: 1rem;
    }
    
    /* 横屏模式优化 */
    @media (orientation: landscape) and (max-height: 600px) {
        .hero {
            padding: var(--spacing-2xl) 0 !important;
        }
        
        .hero-title {
            font-size: 1.75rem !important;
        }
        
        .hero-buttons {
            flex-direction: row !important;
        }
        
        .hero-buttons .btn {
            width: auto !important;
        }
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 var(--spacing-md);
    }
    
    .hero-title {
        font-size: clamp(1.5rem, 6vw, 2rem);
    }
    
    .hero-features {
        grid-template-columns: 1fr;
    }
    
    .services-grid,
    .tech-grid {
        grid-template-columns: 1fr;
    }
    
    .feature-item {
        padding: var(--spacing-lg);
    }
    
    .feature-icon {
        width: 48px;
        height: 48px;
        font-size: 1.25rem;
    }
    
    /* 用户菜单响应式 */
    .user-menu {
        top: 10px;
        right: 10px;
    }
    
    .auth-buttons {
        flex-direction: column;
        gap: 0.4rem;
    }
    
    .btn-login, .btn-register {
        padding: 0.4rem 0.8rem;
        font-size: 0.8rem;
        justify-content: center;
    }
    
    .user-avatar {
        width: 40px;
        height: 40px;
    }
    
    .dropdown-menu {
        min-width: 180px;
        top: 55px;
    }
    
    /* 小屏幕手机特别优化 */
    .hero-buttons .btn {
        padding: 0.75rem 1.25rem;
        font-size: 0.9rem;
    }
    
    .service-icon {
        width: 55px;
        height: 55px;
        font-size: 1.4rem;
    }
    
    .stats {
        grid-template-columns: repeat(2, 1fr);
        gap: var(--spacing-md);
    }
    
    .stat-item {
        padding: var(--spacing-lg) var(--spacing-md);
    }
    
    .stat-number {
        font-size: 1.75rem;
    }
}

/* 平板优化 */
@media (min-width: 768px) and (max-width: 1024px) {
    .hero-title {
        font-size: 2.25rem;
    }
    
    .services-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .tech-grid {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .about-content {
        gap: var(--spacing-2xl);
    }
}

/* 桌面端优化 */
@media (min-width: 1024px) {
    .hero-title {
        font-size: clamp(2.5rem, 4vw, 3.5rem);
    }
    
    .section {
        padding: clamp(4rem, 8vw, 6rem) 0;
    }
}

/* ============ 触控设备优化 ============ */
@media (hover: none) and (pointer: coarse) {
    .global-particle {
        animation-duration: 25s;
    }
    
    /* 移除悬停效果，改用激活状态 */
    .btn-primary:active,
    .btn-secondary:active {
        transform: scale(0.98);
    }
    
    .feature-item:active,
    .service-card:active,
    .tech-item:active,
    .team-item:active,
    .stat-item:active {
        transform: translateY(-5px);
        box-shadow: var(--shadow-lg);
    }
    
    /* 增加触摸目标大小 */
    .btn,
    .dropdown-item,
    .footer-links a {
        min-height: 44px;
    }
    
    .hero-buttons .btn {
        min-height: 52px;
    }
}

/* ============ 减少动画用户优化 ============ */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        animation-delay: 0ms !important;
    }
    
    .global-particle,
    .wave,
    .image-placeholder::after {
        animation: none !important;
        display: none;
    }
    
    .btn-primary::after {
        display: none;
    }
    
    .service-card,
    .tech-item,
    .team-item {
        animation: none !important;
        opacity: 1;
        transform: none;
    }
}

/* ============ 高对比度模式优化 ============ */
@media (prefers-contrast: high) {
    :root {
        --primary: #004080;
        --accent: #0066CC;
        --border: #000000;
    }
    
    .btn {
        border-width: 3px;
    }
    
    .feature-item,
    .service-card,
    .tech-item,
    .team-item,
    .stat-item {
        border: 2px solid var(--border);
    }
}

/* ============ 打印样式优化 ============ */
@media print {
    .background-effects,
    .user-menu,
    .back-to-top,
    .hero-buttons,
    .feature-item,
    .service-card,
    .tech-item,
    .team-item {
        display: none !important;
    }
    
    body {
        background: white !important;
        color: black !important;
        font-size: 12pt;
        line-height: 1.5;
    }
    
    .container {
        max-width: 100% !important;
        padding: 0 !important;
    }
    
    .hero {
        background: white !important;
        padding: 1cm 0 !important;
        text-align: center;
    }
    
    .hero-title {
        background: none !important;
        -webkit-text-fill-color: black !important;
        color: black !important;
        font-size: 24pt !important;
    }
    
    .section {
        padding: 1cm 0 !important;
        page-break-inside: avoid;
    }
    
    .footer {
        background: white !important;
        color: black !important;
        padding: 0.5cm 0 !important;
        border-top: 2pt solid black;
    }
    
    a {
        color: black !important;
        text-decoration: underline;
    }
    
    a[href^="http"]::after {
        content: " (" attr(href) ")";
        font-size: 10pt;
        color: #666;
    }
}

/* ============ 加载状态 ============ */
.loading-spinner {
    padding: var(--spacing-xl);
    text-align: center;
}

.loading-spinner::after {
    content: '';
    display: inline-block;
    width: 40px;
    height: 40px;
    border: 3px solid rgba(0, 102, 204, 0.2);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

.fallback-data {
    display: none;
}

.fallback-data.active {
    display: block;
}

/* ============ 性能优化类 ============ */
.will-change-transform {
    will-change: transform;
}

.will-change-opacity {
    will-change: opacity;
}

.backface-hidden {
    backface-visibility: hidden;
    -webkit-backface-visibility: hidden;
}

/* ============ 文本优化 ============ */
.text-balance {
    text-wrap: balance;
}

.text-pretty {
    text-wrap: pretty;
}

.text-truncate {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

/* ============ 网格系统工具类 ============ */
.grid {
    display: grid;
    gap: var(--spacing-xl);
}

.grid-cols-1 { grid-template-columns: repeat(1, 1fr); }
.grid-cols-2 { grid-template-columns: repeat(2, 1fr); }
.grid-cols-3 { grid-template-columns: repeat(3, 1fr); }
.grid-cols-4 { grid-template-columns: repeat(4, 1fr); }

/* ============ 最终性能优化 ============ */
@media (max-width: 768px) {
    .wave {
        animation-duration: 30s;
    }
    
    .global-particle {
        animation-duration: 20s;
    }
}

/* 强制GPU加速的元素 */
.gpu-accelerated {
    transform: translateZ(0);
    -webkit-transform: translateZ(0);
}

/* 图片加载优化 */
img[loading="lazy"] {
    opacity: 0;
    transition: opacity 0.3s ease;
}

img[loading="lazy"].loaded {
    opacity: 1;
}

/* 自定义焦点样式 */
:focus-visible {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}

/* 禁用状态 */
.btn:disabled,
.btn.disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none !important;
    pointer-events: none;
}

/* 自定义属性回退支持 */
@supports not (color: var(--primary)) {
    :root {
        --primary: #0066CC;
        --primary-dark: #0052A3;
        --primary-light: #3399FF;
        --accent: #00A8FF;
        --secondary: #222222;
        --secondary-light: #444444;
        --bg: #FFFFFF;
        --bg-light: #F5F7FA;
        --bg-dark: #1A1A1A;
        --text: #333333;
        --text-light: #666666;
        --text-white: #FFFFFF;
        --border: #E6E6E6;
        --success: #34C759;
        --warning: #FF9500;
        --error: #FF3B30;
    }
}
/* ============ 时间钟和统计的额外样式 ============ */
.clock-display {
    text-align: center;
    padding: 0.5rem 0;
}

.time-display {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
    margin: 0.5rem 0;
    font-family: 'Courier New', monospace;
    transition: all 0.3s ease;
}

.date-display {
    font-size: 0.9rem;
    color: var(--text-light);
    margin-bottom: 0.25rem;
}

.weekday-display {
    font-size: 0.85rem;
    color: var(--accent);
    font-weight: 600;
    text-transform: uppercase;
}

.stats-container {
    width: 100%;
    min-height: 120px;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 0.75rem;
    margin-top: 0.5rem;
}

.stat-item-small {
    background: rgba(0, 102, 204, 0.05);
    border-radius: var(--radius-sm);
    padding: 0.75rem;
    text-align: center;
    transition: var(--transition);
    border: 1px solid rgba(0, 102, 204, 0.1);
}

.stat-item-small:hover {
    transform: translateY(-3px);
    background: rgba(0, 102, 204, 0.1);
    border-color: var(--primary);
}

.stat-item-small .stat-value {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 0.25rem;
}

.stat-item-small .stat-label {
    font-size: 0.75rem;
    color: var(--text-light);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.stats-footer {
    margin-top: 0.75rem;
    text-align: center;
    padding-top: 0.5rem;
    border-top: 1px solid rgba(0, 102, 204, 0.1);
    color: var(--text-light);
    font-size: 0.7rem;
}

.stats-footer i {
    margin-right: 0.25rem;
    font-size: 0.6rem;
}

.loading-spinner-small {
    padding: 1.5rem;
    text-align: center;
    color: var(--text-light);
}

.loading-spinner-small i {
    margin-right: 0.5rem;
    color: var(--primary);
}

/* 动画 */
@keyframes pulse {
    0% { transform: scale(1); }
    50% { transform: scale(1.05); }
    100% { transform: scale(1); }
}

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

/* 响应式调整 */
@media (max-width: 768px) {
    .time-display {
        font-size: 1.25rem;
    }
    
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 0.5rem;
    }
    
    .stat-item-small {
        padding: 0.5rem;
    }
    
    .stat-item-small .stat-value {
        font-size: 1rem;
    }
}

/* 点击效果 */
.feature-item {
    cursor: pointer;
    user-select: none;
}

.feature-item:active {
    transform: scale(0.98);
}