/* 全局重置与变量 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
:root {
    --bg: #f8f9fa;
    --bg-card: rgba(255,255,255,0.7);
    --text: #1a1a2e;
    --text-light: #555;
    --primary: #e94560;
    --primary-dark: #c23152;
    --accent: #0f3460;
    --gradient1: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
    --gradient2: linear-gradient(135deg, #e94560 0%, #c23152 100%);
    --shadow: 0 8px 32px rgba(0,0,0,0.1);
    --glass: rgba(255,255,255,0.15);
    --border: rgba(255,255,255,0.2);
    --radius: 20px;
    --radius-sm: 12px;
    --transition: 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}
body.dark {
    --bg: #0d1117;
    --bg-card: rgba(30,30,50,0.8);
    --text: #e6e6e6;
    --text-light: #aaa;
    --shadow: 0 8px 32px rgba(0,0,0,0.5);
    --glass: rgba(0,0,0,0.3);
    --border: rgba(255,255,255,0.1);
}
body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    transition: background 0.3s, color 0.3s;
    overflow-x: hidden;
}
a {
    color: var(--primary);
    text-decoration: none;
    transition: color 0.3s;
}
a:hover {
    color: var(--primary-dark);
}
img, svg {
    max-width: 100%;
    height: auto;
    display: block;
}
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}
/* Header */
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 var(--border);
    transition: background 0.3s;
}
.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 24px;
    max-width: 1200px;
    margin: 0 auto;
}
.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text);
}
.logo svg {
    width: 36px;
    height: 36px;
}
nav {
    display: flex;
    align-items: center;
    gap: 12px;
}
nav a {
    padding: 8px 14px;
    border-radius: 30px;
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text);
    transition: background 0.3s, color 0.3s;
}
nav a:hover, nav a.active {
    background: var(--gradient2);
    color: #fff;
}
.menu-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.8rem;
    color: var(--text);
    cursor: pointer;
    padding: 4px 8px;
}
.dark-toggle {
    background: none;
    border: 1px solid var(--border);
    border-radius: 30px;
    padding: 6px 14px;
    font-size: 0.9rem;
    cursor: pointer;
    color: var(--text);
    transition: background 0.3s;
    margin-left: 8px;
}
.dark-toggle:hover {
    background: var(--glass);
}
/* Mobile nav */
.mobile-nav {
    display: none;
    flex-direction: column;
    background: var(--bg-card);
    backdrop-filter: blur(20px);
    padding: 16px 24px;
    border-radius: 0 0 var(--radius) var(--radius);
    border-bottom: 1px solid var(--border);
}
.mobile-nav a {
    padding: 10px 0;
    border-bottom: 1px solid var(--border);
    font-size: 1rem;
}
.mobile-nav a:last-child {
    border-bottom: none;
}
/* Sections */
section {
    padding: 100px 0;
    position: relative;
}
.section-title {
    font-size: 2.4rem;
    font-weight: 700;
    margin-bottom: 20px;
    text-align: center;
    background: var(--gradient2);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}
.section-sub {
    text-align: center;
    max-width: 700px;
    margin: 0 auto 60px;
    color: var(--text-light);
    font-size: 1.1rem;
}
.grid-2, .grid-3, .grid-4 {
    display: grid;
    gap: 30px;
}
.grid-2 { grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }
.grid-3 { grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); }
.grid-4 { grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); }
.card {
    background: var(--bg-card);
    backdrop-filter: blur(10px);
    border-radius: var(--radius);
    padding: 30px;
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
    transition: transform 0.3s, box-shadow 0.3s;
}
.card:hover {
    transform: translateY(-6px);
    box-shadow: 0 12px 40px rgba(0,0,0,0.15);
}
.card-icon {
    width: 60px;
    height: 60px;
    margin-bottom: 16px;
}
.btn {
    display: inline-block;
    padding: 12px 32px;
    border-radius: 30px;
    background: var(--gradient2);
    color: #fff;
    font-weight: 600;
    border: none;
    cursor: pointer;
    transition: transform 0.3s, box-shadow 0.3s;
    box-shadow: 0 4px 15px rgba(233,69,96,0.3);
}
.btn:hover {
    transform: scale(1.05);
    box-shadow: 0 8px 25px rgba(233,69,96,0.4);
}
.btn-outline {
    background: transparent;
    border: 2px solid var(--primary);
    color: var(--primary);
    box-shadow: none;
}
.btn-outline:hover {
    background: var(--primary);
    color: #fff;
}
/* Hero Banner */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    background: var(--gradient1);
    position: relative;
    overflow: hidden;
    padding-top: 80px;
}
.hero-bg {
    position: absolute;
    inset: 0;
    z-index: 0;
}
.hero-bg svg {
    width: 100%;
    height: 100%;
    object-fit: cover;
    opacity: 0.2;
}
.hero-content {
    position: relative;
    z-index: 1;
    max-width: 800px;
    padding: 0 24px;
}
.hero h1 {
    font-size: 4rem;
    font-weight: 800;
    color: #fff;
    margin-bottom: 20px;
    line-height: 1.2;
}
.hero p {
    font-size: 1.3rem;
    color: rgba(255,255,255,0.8);
    margin-bottom: 40px;
}
.hero .btn {
    font-size: 1.1rem;
    padding: 16px 48px;
}
.banner-indicators {
    display: flex;
    justify-content: center;
    gap: 12px;
    margin-top: 40px;
}
.banner-indicators span {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: rgba(255,255,255,0.3);
    cursor: pointer;
    transition: background 0.3s;
}
.banner-indicators span.active {
    background: var(--primary);
}
/* Scroll animation */
.fade-up {
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 0.8s ease, transform 0.8s ease;
}
.fade-up.visible {
    opacity: 1;
    transform: translateY(0);
}
/* FAQ */
.faq-item {
    border-bottom: 1px solid var(--border);
    padding: 16px 0;
}
.faq-question {
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    font-weight: 600;
    font-size: 1.1rem;
    padding: 8px 0;
}
.faq-question span {
    transition: transform 0.3s;
}
.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease, padding 0.3s;
    color: var(--text-light);
}
.faq-answer.open {
    max-height: 300px;
    padding: 12px 0;
}
/* Footer */
footer {
    background: var(--gradient1);
    color: rgba(255,255,255,0.8);
    padding: 60px 0 30px;
}
footer a {
    color: rgba(255,255,255,0.7);
}
footer a:hover {
    color: #fff;
}
.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 40px;
}
.footer-bottom {
    border-top: 1px solid rgba(255,255,255,0.1);
    padding-top: 30px;
    margin-top: 40px;
    text-align: center;
    font-size: 0.9rem;
}
/* Breadcrumb */
.breadcrumb {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
    padding: 16px 0;
    font-size: 0.9rem;
    color: var(--text-light);
}
.breadcrumb a {
    color: var(--text-light);
}
/* Search */
.search-box {
    display: flex;
    gap: 8px;
    max-width: 400px;
    margin: 20px auto;
}
.search-box input {
    flex: 1;
    padding: 12px 20px;
    border-radius: 30px;
    border: 1px solid var(--border);
    background: var(--bg-card);
    color: var(--text);
    font-size: 1rem;
    outline: none;
}
.search-box button {
    padding: 12px 24px;
    border-radius: 30px;
    background: var(--gradient2);
    color: #fff;
    border: none;
    cursor: pointer;
}
/* Back to top */
.back-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: var(--gradient2);
    color: #fff;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    box-shadow: 0 4px 15px rgba(233,69,96,0.3);
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.3s, transform 0.3s;
    z-index: 999;
}
.back-top.show {
    opacity: 1;
    transform: translateY(0);
}
/* Responsive */
@media (max-width: 768px) {
    .header-inner nav {
        display: none;
    }
    .menu-toggle {
        display: block;
    }
    .mobile-nav.open {
        display: flex;
    }
    .hero h1 {
        font-size: 2.6rem;
    }
    .section-title {
        font-size: 1.8rem;
    }
    section {
        padding: 60px 0;
    }
    .grid-2, .grid-3, .grid-4 {
        grid-template-columns: 1fr;
    }
}
@media (min-width: 769px) {
    .mobile-nav {
        display: none !important;
    }
}