:root {
    --primary: #4c6fff;
    --primary-2: #409eff;
    --primary-dark: #3d58db;
    --navy: #0b102a;
    --text: #303133;
    --muted: #606266;
    --gray: #909399;
    --line: #ebeef5;
    --bg: #f8faff;
    --card: #ffffff;
    --radius: 14px;
    --shadow: 0 12px 40px rgba(27, 77, 203, 0.08);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
    margin: 0;
    color: var(--text);
    background: #fff;
    font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
    line-height: 1.65;
}
a { color: inherit; text-decoration: none; }
button, input { font: inherit; }
img { max-width: 100%; }
.container { width: min(1180px, calc(100% - 40px)); margin: 0 auto; }

.site-header {
    position: sticky;
    top: 0;
    z-index: 40;
    background: rgba(255,255,255,.92);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid transparent;
}
.site-header.scrolled { border-bottom-color: var(--line); box-shadow: 0 4px 18px rgba(11,16,42,.04); }
.header-inner { display: flex; align-items: center; gap: 24px; min-height: 72px; }
.logo { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 18px; white-space: nowrap; }
.logo-img { width: 36px; height: 36px; border-radius: 10px; display: block; flex: 0 0 36px; }
.logo-copy { display: flex; flex-direction: column; line-height: 1.15; }
.logo-text { font-size: 16px; }
.logo-sub { font-size: 11px; font-weight: 500; color: var(--gray); letter-spacing: .02em; }
.logo.light { color: #fff; }
.logo.light .logo-sub { color: rgba(255,255,255,.62); }
.nav { display: flex; align-items: center; gap: 6px; margin-left: auto; }
.nav-link {
    display: inline-flex; align-items: center; gap: 6px;
    padding: 8px 12px; border-radius: 8px; color: var(--muted); font-size: 14px;
}
.nav-link:hover, .nav-link.active { color: var(--primary); background: #ecf5ff; }
.nav-item { position: relative; }
.mega-menu {
    display: none; position: absolute; top: 100%; left: 0; width: 340px;
    background: #fff; border: 1px solid var(--line); border-radius: 12px;
    box-shadow: var(--shadow); padding: 8px; z-index: 20;
}
.nav-item:hover .mega-menu { display: grid; }
.mega-menu a {
    display: flex; gap: 12px; align-items: flex-start;
    padding: 10px 12px; border-radius: 10px;
}
.mega-menu a:hover { background: #f5f7fa; }
.mega-menu i { width: 28px; color: var(--primary); margin-top: 3px; }
.mega-menu strong { display: block; font-size: 14px; }
.mega-menu em { display: block; font-style: normal; color: var(--gray); font-size: 12px; }
.header-actions { display: flex; align-items: center; gap: 10px; }
.nav-toggle { display: none; border: 0; background: #f5f7fa; width: 40px; height: 40px; border-radius: 10px; }

.btn {
    display: inline-flex; align-items: center; justify-content: center; gap: 8px;
    border: 1px solid transparent; border-radius: 10px; padding: 9px 16px;
    cursor: pointer; background: #fff; color: var(--text); transition: .2s ease;
}
.btn.sm { padding: 7px 12px; font-size: 13px; }
.btn.lg { padding: 12px 20px; font-size: 15px; }
.btn-primary { background: var(--primary); color: #fff; box-shadow: 0 8px 18px rgba(76,111,255,.24); }
.btn-primary:hover { background: var(--primary-dark); }
.btn-outline { border-color: #dcdfe6; background: #fff; }
.btn-outline:hover { border-color: var(--primary); color: var(--primary); }
.btn-ghost { background: transparent; color: var(--muted); }
.btn-light { background: #fff; color: var(--navy); }

.hero {
    background:
        radial-gradient(circle at 85% 10%, rgba(76,111,255,.16), transparent 28%),
        linear-gradient(180deg, #f8faff 0%, #fff 100%);
    padding: 56px 0 36px;
}
.hero-grid { display: grid; grid-template-columns: 1.05fr .95fr; gap: 48px; align-items: center; }
.eyebrow { color: var(--primary); font-weight: 600; margin: 0 0 10px; letter-spacing: .04em; }
.hero h1 { font-size: 46px; line-height: 1.2; margin: 0 0 16px; letter-spacing: -0.02em; }
.hero h1 span { color: var(--primary); }
.lead { color: var(--muted); font-size: 16px; margin: 0 0 20px; }
.feature-pills { display: flex; flex-wrap: wrap; gap: 8px; padding: 0; margin: 0 0 24px; list-style: none; }
.feature-pills li {
    padding: 6px 12px; border-radius: 999px; background: #ecf5ff; color: #3a8ee6; font-size: 13px;
}
.hero-actions { display: flex; gap: 12px; flex-wrap: wrap; }
.hero-note { color: var(--gray); font-size: 13px; margin: 16px 0 0; }
.hero-note i { color: var(--primary-2); }

.window {
    background: #fff; border: 1px solid var(--line); border-radius: 18px;
    box-shadow: var(--shadow); overflow: hidden;
}
.window-bar {
    display: flex; align-items: center; gap: 6px;
    padding: 12px 16px; background: #f5f7fa; border-bottom: 1px solid var(--line);
}
.window-bar span { width: 10px; height: 10px; border-radius: 50%; background: #dcdfe6; }
.window-bar span:first-child { background: #f56c6c; }
.window-bar span:nth-child(2) { background: #e6a23c; }
.window-bar span:nth-child(3) { background: #67c23a; }
.window-bar em { margin-left: 10px; font-style: normal; color: var(--gray); font-size: 13px; }
.window-body { display: grid; grid-template-columns: 180px 1fr; min-height: 320px; }
.window-body aside { border-right: 1px solid var(--line); padding: 12px; background: #fcfdff; }
.account { display: flex; gap: 10px; padding: 10px; border-radius: 10px; margin-bottom: 8px; }
.account.active, .account:hover { background: #ecf5ff; }
.account i { width: 32px; height: 32px; border-radius: 8px; display: grid; place-items: center; background: var(--navy); color: #fff; }
.account strong, .account small { display: block; }
.account small { color: var(--gray); font-size: 12px; }
.chat { padding: 18px; display: flex; flex-direction: column; gap: 10px; }
.bubble { max-width: 86%; padding: 10px 12px; border-radius: 12px; font-size: 13px; }
.bubble.in { background: #f5f7fa; align-self: flex-start; }
.bubble.out { background: var(--primary); color: #fff; align-self: flex-end; }
.card-msg {
    display: flex; gap: 10px; align-items: center;
    border: 1px solid #d6e4ff; background: #f8faff; border-radius: 12px; padding: 10px;
}
.card-msg .thumb {
    width: 42px; height: 42px; border-radius: 8px; background: var(--primary); color: #fff;
    display: grid; place-items: center;
}
.card-msg small { color: var(--primary); }
.rule { font-size: 12px; color: #3a8ee6; background: #ecf5ff; border-radius: 8px; padding: 8px 10px; }

.stats { padding: 20px 0 10px; }
.stats-inner {
    display: flex; align-items: center; justify-content: space-between; gap: 24px;
    padding: 22px 28px; border: 1px solid var(--line); border-radius: 16px; background: #fff;
}
.stat-main { display: flex; align-items: baseline; gap: 8px; }
.stat-main strong { font-size: 36px; color: var(--primary); }
.stat-main span, .stats-inner > p { color: var(--muted); margin: 0; }
.stat-tags { display: flex; gap: 8px; flex-wrap: wrap; }
.stat-tags span { background: #f5f7fa; color: var(--muted); padding: 4px 10px; border-radius: 999px; font-size: 12px; }

.section { padding: 72px 0; }
.section.alt { background: var(--bg); }
.section.slim { padding: 40px 0 72px; }
.section-head { margin-bottom: 32px; }
.section-head h2, .scene-grid h2, .cta h2, .help-row h2 { font-size: 32px; line-height: 1.3; margin: 0 0 12px; }
.section-head em { color: var(--primary); font-style: normal; }

.product-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.product-card {
    background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
    padding: 22px; min-height: 168px; transition: .2s ease;
}
.product-card:hover { transform: translateY(-4px); box-shadow: var(--shadow); border-color: #d6e4ff; }
.product-card i { color: var(--primary); font-size: 22px; margin-bottom: 14px; }
.product-card h3 { margin: 0 0 8px; font-size: 16px; }
.product-card p { margin: 0; color: var(--muted); font-size: 13px; }

.scene-grid { display: grid; grid-template-columns: .9fr 1.1fr; gap: 36px; align-items: center; }
.scene-tags { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 20px; }
.scene-tags span, .filter-tabs button, .mini-chips em {
    border: 1px solid var(--line); background: #fff; border-radius: 999px; padding: 7px 14px; font-size: 13px; color: var(--muted);
}
.scene-tags span.on, .filter-tabs button.on { background: var(--primary); color: #fff; border-color: var(--primary); }
.scene-card { background: #fff; border-radius: 18px; padding: 28px; box-shadow: var(--shadow); }
.scene-card h3 { margin: 0 0 8px; }
.scene-card ul { padding: 0; margin: 16px 0; list-style: none; }
.scene-card li { margin-bottom: 8px; color: var(--muted); }
.scene-card i { color: #67c23a; margin-right: 6px; }
.mini-chips { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 18px; }

.filter-tabs { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 16px; }
.filter-tabs button { cursor: pointer; }
.news-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.news-card {
    border: 1px solid var(--line); border-radius: var(--radius); padding: 20px; background: #fff; min-height: 220px;
}
.news-card:hover { box-shadow: var(--shadow); }
.news-tag { color: var(--primary); font-size: 12px; margin-bottom: 12px; }
.news-card h3 { font-size: 16px; margin: 0 0 10px; line-height: 1.45; }
.news-card p { color: var(--muted); font-size: 13px; }
.news-card span { color: var(--gray); font-size: 12px; }
.center { text-align: center; margin-top: 28px; }
.more-link { color: var(--primary); font-weight: 600; }

.cta {
    background:
        linear-gradient(135deg, rgba(76,111,255,.92), rgba(11,16,42,.94)),
        var(--navy);
    color: #fff; padding: 72px 0;
}
.cta-inner { text-align: center; }
.cta p, .cta small { color: rgba(255,255,255,.78); }
.cta ul { display: flex; justify-content: center; gap: 22px; list-style: none; padding: 0; flex-wrap: wrap; }
.cta .hero-actions { justify-content: center; margin: 20px 0 12px; }
.help-row { display: flex; justify-content: space-between; gap: 24px; align-items: center; background: #f8faff; border: 1px solid var(--line); border-radius: 16px; padding: 28px; }
.help-row p { color: var(--muted); margin: 0; }
.help-actions { display: flex; gap: 10px; }

.site-footer { background: var(--navy); color: #c0c4cc; padding: 56px 0 20px; }
.footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1fr; gap: 32px; }
.footer-desc { color: #909399; max-width: 320px; }
.footer-social { display: flex; gap: 10px; }
.footer-social button {
    width: 36px; height: 36px; border: 0; border-radius: 8px; background: #1b2144; color: #fff; cursor: pointer;
}
.site-footer h4 { color: #fff; margin: 0 0 14px; }
.site-footer a, .site-footer p { display: block; margin: 0 0 10px; color: #c0c4cc; }
.footer-bottom {
    margin-top: 28px; padding-top: 18px; border-top: 1px solid #1b2144;
    display: flex; justify-content: space-between; gap: 16px; font-size: 13px; align-items: center;
}
.beian { display: flex; flex-wrap: wrap; gap: 8px 16px; color: #909399; }
.beian a { display: inline; margin: 0; color: #c0c4cc; }
.beian a:hover { color: #fff; }

.modal-mask {
    position: fixed; inset: 0; background: rgba(11,16,42,.45);
    display: grid; place-items: center; z-index: 80; padding: 20px;
}
.modal-mask[hidden] { display: none; }
.modal-box { width: min(440px, 100%); background: #fff; border-radius: 18px; padding: 32px 28px 24px; position: relative; }
.modal-close { position: absolute; right: 14px; top: 14px; border: 0; background: #f5f7fa; width: 32px; height: 32px; border-radius: 8px; cursor: pointer; }
.modal-icon { width: 48px; height: 48px; border-radius: 12px; background: #ecf5ff; color: var(--primary); display: grid; place-items: center; font-size: 20px; }
.modal-list { list-style: none; padding: 0; color: var(--muted); }
.modal-list i { color: #67c23a; margin-right: 8px; }
.modal-actions { display: flex; justify-content: flex-end; }

@media (max-width: 980px) {
    .nav { display: none; position: absolute; top: 72px; left: 0; right: 0; background: #fff; border-bottom: 1px solid var(--line); padding: 12px; flex-direction: column; align-items: stretch; }
    .nav.open { display: flex; }
    .nav-toggle { display: inline-grid; place-items: center; }
    .nav-item:hover .mega-menu, .mega-menu { position: static; width: auto; display: none; box-shadow: none; }
    .nav-item.open .mega-menu { display: grid; }
    .hero-grid, .scene-grid, .product-grid, .news-grid, .footer-grid, .stats-inner, .help-row { grid-template-columns: 1fr; }
    .hero h1 { font-size: 32px; }
    .window-body { grid-template-columns: 1fr; }
    .window-body aside { display: none; }
    .header-actions .btn-ghost { display: none; }
    .footer-bottom { flex-direction: column; align-items: flex-start; }
}