/* 全局样式 */
:root {
    /* 主色调 */
    --primary-color: #63acf1;
    --primary-dark: #3877ca;
    --primary-light: #81b1f8;
    
    /* 渐变色 */
    --gradient-primary: linear-gradient(135deg, #00a2ff 0%, #00ffff 100%);
    --gradient-secondary: linear-gradient(135deg, #3b82f6 0%, #1e40af 100%);
    --gradient-accent: linear-gradient(135deg, #ec4899 0%, #337cea 100%);
    
    /* 背景色 */
    --bg-dark: #0f172a;
    --bg-darker: #020617;
    --bg-light: #1e293b;
    --bg-lighter: #334155;
    
    /* 文本颜色 */
    --text-primary: #f8fafc;
    --text-secondary: #cbd5e1;
    --text-muted: #94a3b8;
    
    /* 其他颜色 */
    --success: #10b981;
    --warning: #f59e0b;
    --error: #ef4444;
    --info: #0ea5e9;
    
    /* 间距 */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 0.75rem;
    --spacing-lg: 1.25rem;
    --spacing-xl: 1.5rem;
    --spacing-2xl: 2rem;
    --spacing-3xl: 2.5rem;
    
    /* 圆角 */
    --radius-sm: 0.25rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-full: 9999px;
    
    /* 阴影 */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-hover: 0 15px 25px -5px rgba(0, 0, 0, 0.2), 0 10px 10px -5px rgba(0, 0, 0, 0.1);
    --shadow-glow: 0 0 15px rgba(99, 172, 241, 0.4);
    
    /* 过渡 */
    --transition-fast: 0.15s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
    --transition-bounce: 0.5s cubic-bezier(0.68, -0.55, 0.27, 1.55);
    
    /* 布局 */
    --container-padding: 1.5rem;
    --header-height: 4rem;
}

/* 基本重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

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

body {
    font-family: 'Inter', 'SF Pro Display', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    background-color: var(--bg-dark);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    transition: background-color var(--transition-normal);
}

h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.3;
    margin-bottom: var(--spacing-md);
}

h1 {
    font-size: 2.5rem;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

h2 {
    font-size: 2rem;
    position: relative;
}

h2::after {
    content: '';
    position: absolute;
    bottom: -0.5rem;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background: var(--gradient-primary);
    border-radius: var(--radius-full);
}

h3 {
    font-size: 1.5rem;
}

h4 {
    font-size: 1.25rem;
}

p {
    margin-bottom: var(--spacing-md);
}

a {
    color: var(--primary-light);
    text-decoration: none;
    transition: all var(--transition-normal);
    position: relative;
}

a:hover {
    color: var(--primary-color);
}

a:not(.btn):after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 0;
    height: 1px;
    background: var(--primary-color);
    transition: width var(--transition-normal);
}

a:not(.btn):hover:after {
    width: 100%;
}

img {
    max-width: 100%;
    height: auto;
    border: none;
    transition: transform 0.5s ease, filter 0.5s ease;
}

ul, ol {
    padding-left: var(--spacing-xl);
    margin-bottom: var(--spacing-md);
}

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

/* 按钮样式 */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.625rem 1.25rem;
    border-radius: var(--radius-md);
    font-weight: 500;
    font-size: 0.875rem;
    line-height: 1;
    text-align: center;
    cursor: pointer;
    transition: all var(--transition-bounce);
    border: none;
    outline: none;
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: rgba(255, 255, 255, 0.2);
    transition: all 0.4s ease;
}

.btn:hover::before {
    left: 100%;
}

.btn i {
    margin-right: 0.5rem;
}

.btn-primary {
    background: var(--gradient-primary);
    color: white;
    box-shadow: 0 4px 6px rgba(99, 102, 241, 0.25);
}

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

.btn-primary:active {
    transform: translateY(-1px);
}

.btn-secondary {
    background: var(--bg-lighter);
    color: var(--text-primary);
}

.btn-secondary:hover {
    background: var(--bg-light);
    color: var(--text-primary);
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.btn-outline {
    background: transparent;
    border: 1px solid var(--primary-color);
    color: var(--primary-color);
}

.btn-outline:hover {
    background: var(--primary-color);
    color: white;
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.btn-cta {
    background: var(--gradient-accent);
    color: white;
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    box-shadow: 0 4px 6px rgba(236, 72, 153, 0.25);
}

.btn-cta:hover {
    box-shadow: var(--shadow-hover), 0 0 20px rgba(236, 72, 153, 0.4);
    transform: translateY(-3px) scale(1.05);
    color: white;
}

.btn-cta:active {
    transform: translateY(-1px) scale(1.02);
}

/* 导航栏 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: var(--header-height);
    background: rgba(15, 23, 42, 0.8);
    backdrop-filter: blur(10px);
    z-index: 1000;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    transition: all var(--transition-normal);
}

.navbar .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
}

.logo {
    display: flex;
    align-items: center;
}

.logo a {
    display: flex;
    align-items: center;
    color: var(--text-primary);
    font-weight: 600;
    transition: transform var(--transition-normal);
}

.logo a:hover {
    transform: scale(1.05);
}

.logo a:after {
    display: none;
}

.logo img {
    height: 2rem;
    margin-right: 0.5rem;
}

.nav-links {
    display: flex;
    gap: 1.5rem;
}

.nav-links a {
    color: var(--text-secondary);
    position: relative;
    padding: 0.5rem 0;
    font-weight: 500;
}

.nav-links a:hover, .nav-links a.active {
    color: var(--text-primary);
}

.nav-links a:after {
    display: none;
}

.nav-links a.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 2px;
    background: var(--gradient-primary);
    border-radius: var(--radius-full);
}

.nav-links a:not(.active)::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 2px;
    background: var(--gradient-primary);
    border-radius: var(--radius-full);
    transition: width var(--transition-normal);
}

.nav-links a:not(.active):hover::after {
    width: 100%;
}

.nav-buttons {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.mobile-menu-btn {
    display: none;
    background: transparent;
    border: none;
    color: var(--text-primary);
    font-size: 1.25rem;
    cursor: pointer;
    transition: transform var(--transition-fast);
}

.mobile-menu-btn:hover {
    transform: rotate(90deg);
}

.mobile-menu {
    display: none;
    position: fixed;
    top: var(--header-height);
    left: 0;
    width: 100%;
    background: var(--bg-dark);
    padding: 1rem;
    flex-direction: column;
    gap: 1rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    z-index: 999;
    transform: translateY(-10px);
    opacity: 0;
    transition: all var(--transition-normal);
}

.mobile-menu a {
    color: var(--text-secondary);
    padding: 0.75rem 0;
    font-weight: 500;
    transform: translateX(-10px);
    opacity: 0;
    transition: all var(--transition-normal);
}

.mobile-menu-open {
    display: flex;
    transform: translateY(0);
    opacity: 1;
}

.mobile-menu-open a {
    transform: translateX(0);
    opacity: 1;
    transition-delay: calc(var(--i, 0) * 0.1s);
}

.mobile-menu a.active, .mobile-menu a:hover {
    color: var(--text-primary);
}

.mobile-menu .btn {
    margin-top: 0.5rem;
}

/* 页脚 */
footer {
    background-color: var(--bg-darker);
    padding: var(--spacing-2xl) 0 var(--spacing-xl);
    margin-top: var(--spacing-3xl);
    position: relative;
    overflow: hidden;
}

footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--primary-light), transparent);
}

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

.footer-logo img {
    height: 2rem;
    margin-bottom: var(--spacing-md);
}

.footer-logo p {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
}

.footer-links h4 {
    color: var(--text-primary);
    margin-bottom: var(--spacing-md);
    font-size: 1rem;
}

.footer-links a {
    display: block;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-sm);
    transition: all var(--transition-normal);
}

.footer-links a:hover {
    color: var(--text-primary);
    transform: translateX(5px);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: var(--spacing-lg);
    text-align: center;
    color: var(--text-muted);
    font-size: 0.875rem;
}

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

.footer-bottom a {
    color: var(--text-muted);
    transition: color var(--transition-normal);
}

.footer-bottom a:hover {
    color: var(--primary-light);
}

/* 动画类 */
.animate-fade-up {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease, transform 0.8s ease;
}

.animate-fade-up.animated {
    opacity: 1;
    transform: translateY(0);
}

.animate-fade-in {
    opacity: 0;
    transition: opacity 0.8s ease;
}

.animate-fade-in.animated {
    opacity: 1;
}

.animate-scale-in {
    opacity: 0;
    transform: scale(0.9);
    transition: opacity 0.8s ease, transform 0.8s ease;
}

.animate-scale-in.animated {
    opacity: 1;
    transform: scale(1);
}

.stagger-delay-1 {
    transition-delay: 0.1s;
}

.stagger-delay-2 {
    transition-delay: 0.2s;
}

.stagger-delay-3 {
    transition-delay: 0.3s;
}

.stagger-delay-4 {
    transition-delay: 0.4s;
}

/* 响应式设计 */
@media (max-width: 992px) {
    h1 {
        font-size: 2.25rem;
    }
    
    h2 {
        font-size: 1.75rem;
    }
    
    .footer-grid {
        grid-template-columns: 1fr 1fr;
        gap: var(--spacing-xl) var(--spacing-lg);
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    
    .mobile-menu-btn {
        display: block;
    }
    
    .footer-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-xl);
    }
}

@media (max-width: 576px) {
    h1 {
        font-size: 2rem;
    }
    
    h2 {
        font-size: 1.5rem;
    }
    
    .container {
        padding: 0 1rem;
    }
}

/* 公共部分样式 */
section {
    padding: var(--spacing-2xl) 0;
    position: relative;
}

section h2 {
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

.section-desc {
    text-align: center;
    color: var(--text-secondary);
    max-width: 600px;
    margin: -1rem auto var(--spacing-xl);
}