/* 全局变量与重置 */
:root {
    --primary: #1a1a2e;
    --secondary: #16213e;
    --accent: #e94560;
    --accent2: #0f3460;
    --light: #f8f9fa;
    --dark: #0d0d0d;
    --glass: rgba(255,255,255,0.08);
    --shadow: 0 8px 32px rgba(0,0,0,0.3);
    --radius: 16px;
    --transition: 0.3s ease;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
body {
    font-family: system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
    background: var(--primary);
    color: var(--light);
    line-height: 1.7;
    overflow-x: hidden;
}
a { color: inherit; text-decoration: none; }
img, svg { max-width: 100%; height: auto; display: block; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }

/* 亮色模式 */
body.light-mode {
    --primary: #f0f2f5;
    --secondary: #ffffff;
    --light: #1a1a2e;
    --dark: #f8f9fa;
    --glass: rgba(0,0,0,0.05);
    --shadow: 0 8px 32px rgba(0,0,0,0.1);
}

/* 导航 */
header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    background: var(--glass);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(255,255,255,0.05);
    transition: var(--transition);
}
header.scrolled { background: rgba(26,26,46,0.95); }
body.light-mode header.scrolled { background: rgba(255,255,255,0.95); }
.nav-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}
.logo {
    font-size: 1.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, #e94560, #0f3460);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}
.nav-links { display: flex; gap: 2rem; list-style: none; font-size: 0.95rem; }
.nav-links a {
    opacity: 0.8;
    transition: var(--transition);
    position: relative;
}
.nav-links a:hover, .nav-links a.active { opacity: 1; }
.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent);
    transition: var(--transition);
}
.nav-links a:hover::after, .nav-links a.active::after { width: 100%; }
.menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    background: none;
    border: none;
    padding: 10px;
}
.menu-toggle span {
    width: 28px;
    height: 2px;
    background: var(--light);
    border-radius: 2px;
    transition: var(--transition);
}
.theme-toggle {
    background: var(--glass);
    border: 1px solid rgba(255,255,255,0.1);
    color: var(--light);
    padding: 8px 16px;
    border-radius: 30px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: var(--transition);
}
.theme-toggle:hover { background: var(--accent); }

/* 移动菜单 */
.mobile-nav {
    display: none;
    position: fixed;
    top: 70px;
    left: 0;
    width: 100%;
    background: var(--primary);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    padding: 20px;
    flex-direction: column;
    gap: 1rem;
    border-bottom: 1px solid rgba(255,255,255,0.05);
    z-index: 999;
}
.mobile-nav.open { display: flex; }
.mobile-nav a { padding: 10px 0; border-bottom: 1px solid rgba(255,255,255,0.05); }

/* Hero */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    overflow: hidden;
    padding-top: 70px;
}
.hero-bg {
    position: absolute;
    inset: 0;
    background: radial-gradient(ellipse at 30% 50%, #0f3460 0%, transparent 60%),
                radial-gradient(ellipse at 70% 50%, #e94560 0%, transparent 50%);
    opacity: 0.3;
}
.hero-content { position: relative; z-index: 2; text-align: center; max-width: 800px; margin: 0 auto; }
.hero h1 {
    font-size: 3.5rem;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 1.5rem;
    background: linear-gradient(135deg, #fff, #e94560);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}
.hero p { font-size: 1.2rem; opacity: 0.9; margin-bottom: 2.5rem; }
.hero-buttons { display: flex; gap: 1.5rem; justify-content: center; flex-wrap: wrap; }

/* 按钮 */
.btn {
    padding: 14px 36px;
    border-radius: 50px;
    font-weight: 600;
    border: none;
    cursor: pointer;
    transition: var(--transition);
    font-size: 1rem;
}
.btn-primary {
    background: var(--accent);
    color: #fff;
    box-shadow: 0 4px 20px rgba(233,69,96,0.4);
}
.btn-primary:hover { transform: translateY(-3px); box-shadow: 0 8px 30px rgba(233,69,96,0.6); }
.btn-outline { background: transparent; border: 2px solid var(--light); color: var(--light); }
.btn-outline:hover { background: var(--light); color: var(--primary); }

/* 通用section */
section { padding: 100px 0; }
.section-title {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
}
.section-sub {
    text-align: center;
    opacity: 0.7;
    max-width: 600px;
    margin: 0 auto 60px;
}

/* 卡片网格 */
.grid-3 { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 30px; }
.grid-4 { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 24px; }
.card {
    background: var(--glass);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-radius: var(--radius);
    padding: 30px;
    border: 1px solid rgba(255,255,255,0.05);
    transition: var(--transition);
    box-shadow: var(--shadow);
}
.card:hover { transform: translateY(-8px); border-color: var(--accent); }
.card-icon { margin-bottom: 20px; width: 60px; height: 60px; }
.card h3 { font-size: 1.4rem; margin-bottom: 12px; }
.card p { opacity: 0.8; font-size: 0.95rem; }

/* 轮播 */
.carousel { position: relative; overflow: hidden; border-radius: var(--radius); }
.carousel-track { display: flex; transition: transform 0.5s ease; }
.carousel-slide {
    min-width: 100%;
    padding: 40px;
    background: var(--glass);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    text-align: center;
}
.carousel-slide h3 { font-size: 1.8rem; margin-bottom: 1rem; }
.carousel-btn {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background: var(--glass);
    border: none;
    color: var(--light);
    width: 50px;
    height: 50px;
    border-radius: 50%;
    cursor: pointer;
    font-size: 1.5rem;
    transition: var(--transition);
    z-index: 10;
}
.carousel-btn:hover { background: var(--accent); }
.carousel-btn.prev { left: 10px; }
.carousel-btn.next { right: 10px; }

/* FAQ */
.faq-item {
    margin-bottom: 16px;
    border-radius: var(--radius);
    overflow: hidden;
    background: var(--glass);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid rgba(255,255,255,0.05);
}
.faq-question {
    padding: 20px 24px;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-weight: 600;
    font-size: 1.05rem;
    transition: var(--transition);
}
.faq-question:hover { background: rgba(255,255,255,0.05); }
.faq-question .icon { transition: var(--transition); font-size: 1.2rem; }
.faq-item.active .faq-question .icon { transform: rotate(45deg); }
.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease;
    padding: 0 24px;
}
.faq-item.active .faq-answer { max-height: 400px; padding: 0 24px 20px; }

/* 数字动画 */
.stats-grid { display: flex; justify-content: center; gap: 60px; flex-wrap: wrap; margin: 60px 0; }
.stat-item { text-align: center; }
.stat-number {
    font-size: 3rem;
    font-weight: 800;
    background: linear-gradient(135deg, #e94560, #0f3460);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}
.stat-label { opacity: 0.7; margin-top: 8px; }

/* 滚动动画 */
.fade-up {
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 0.8s ease, transform 0.8s ease;
}
.fade-up.visible { opacity: 1; transform: translateY(0); }

/* 回到顶部 */
.back-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: var(--accent);
    color: #fff;
    border: none;
    cursor: pointer;
    font-size: 1.5rem;
    box-shadow: 0 4px 20px rgba(233,69,96,0.4);
    transition: var(--transition);
    z-index: 100;
    display: none;
}
.back-top.show { display: block; }
.back-top:hover { transform: scale(1.1); }

/* Footer */
footer { background: var(--secondary); padding: 60px 0 30px; border-top: 1px solid rgba(255,255,255,0.05); }
.footer-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 40px; margin-bottom: 40px; }
.footer-col h4 { margin-bottom: 20px; font-size: 1.1rem; }
.footer-col ul { list-style: none; }
.footer-col li { margin-bottom: 10px; opacity: 0.7; transition: var(--transition); }
.footer-col li:hover { opacity: 1; }
.footer-bottom { text-align: center; padding-top: 30px; border-top: 1px solid rgba(255,255,255,0.05); opacity: 0.6; font-size: 0.9rem; }

/* 面包屑 */
.breadcrumb { display: flex; gap: 10px; list-style: none; padding: 20px 0; font-size: 0.9rem; opacity: 0.7; }
.breadcrumb li+li::before { content: '/'; margin-right: 10px; }

/* 搜索框 */
.search-box {
    display: flex;
    max-width: 400px;
    margin: 20px auto;
    background: var(--glass);
    border-radius: 50px;
    overflow: hidden;
    border: 1px solid rgba(255,255,255,0.1);
}
.search-box input {
    flex: 1;
    padding: 14px 20px;
    background: transparent;
    border: none;
    color: var(--light);
    outline: none;
    font-size: 1rem;
}
.search-box button {
    padding: 14px 24px;
    background: var(--accent);
    border: none;
    color: #fff;
    cursor: pointer;
    font-weight: 600;
    transition: var(--transition);
}
.search-box button:hover { background: #d63852; }

/* 响应式 */
@media (max-width: 768px) {
    .nav-links { display: none; }
    .menu-toggle { display: flex; }
    .hero h1 { font-size: 2.2rem; }
    .section-title { font-size: 2rem; }
    .stats-grid { gap: 30px; }
    .carousel-slide { padding: 20px; }
}
@media (max-width: 480px) {
    .hero h1 { font-size: 1.8rem; }
    .btn { padding: 12px 24px; font-size: 0.9rem; }
}