/* ============ 基础 ============ */
:root {
  --bg: #ffffff;
  --bg-2: #f5f7fb;
  --bg-3: #eef1f7;
  --card: #ffffff;
  --border: rgba(15, 23, 42, 0.10);
  --text: #0f172a;
  --muted: #5b6b7f;
  --accent: #0284c7;
  --accent-2: #6366f1;
  --accent-3: #0e7490;
  --grad: linear-gradient(120deg, #0284c7, #6366f1 55%, #0e7490);
  --radius: 16px;
  --maxw: 1140px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; }

/* ============ 导航 ============ */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  backdrop-filter: blur(14px);
  background: rgba(255, 255, 255, 0.85);
  border-bottom: 1px solid var(--border);
  transition: background .3s;
}
.nav-inner {
  max-width: var(--maxw); margin: 0 auto; padding: 14px 24px;
  display: flex; align-items: center; gap: 28px;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 19px; }
.brand-logo {
  display: inline-grid; place-items: center; width: 34px; height: 34px;
  background: var(--grad); border-radius: 9px; color: #fff; font-size: 18px;
}
.nav-links { display: flex; gap: 24px; margin-left: auto; }
.nav-links a { color: var(--muted); font-size: 15px; transition: color .2s; }
.nav-links a:hover { color: var(--text); }
.nav-cta {
  padding: 9px 20px; border-radius: 10px; background: var(--grad);
  color: #fff; font-weight: 600; font-size: 14px; white-space: nowrap;
}
.lang-switch { display: flex; align-items: center; gap: 6px; }
.lang-btn {
  background: none; border: none; cursor: pointer; color: var(--muted);
  font-size: 13px; font-weight: 600; padding: 4px 7px; border-radius: 6px; transition: all .2s;
}
.lang-btn:hover { color: var(--text); }
.lang-btn.active { color: #fff; background: var(--grad); }
.lang-sep { color: var(--muted); font-size: 12px; }
.nav-toggle { display: none; background: none; border: none; color: var(--text); font-size: 24px; cursor: pointer; }

/* ============ Hero ============ */
.hero {
  position: relative; min-height: 100vh; display: flex; align-items: center;
  padding: 120px 24px 80px; overflow: hidden;
}
.hero-bg { position: absolute; inset: 0; z-index: -1; }
.grid-overlay {
  position: absolute; inset: 0;
  background-image: linear-gradient(rgba(2,132,199,.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(2,132,199,.05) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse at 50% 40%, #000 30%, transparent 75%);
}
.orb { position: absolute; border-radius: 50%; filter: blur(90px); opacity: .16; }
.orb-1 { width: 460px; height: 460px; background: #2563eb; top: -120px; right: -80px; }
.orb-2 { width: 380px; height: 380px; background: #7c3aed; bottom: -120px; left: -100px; opacity: .12; }
.orb-3 { width: 280px; height: 280px; background: #06b6d4; top: 40%; left: 55%; opacity: .10; }
.hero-inner { max-width: var(--maxw); margin: 0 auto; width: 100%; }
.hero-badge {
  display: inline-block; padding: 7px 16px; border-radius: 999px;
  border: 1px solid var(--border); background: rgba(56,189,248,.08);
  color: var(--accent); font-size: 13px; letter-spacing: .5px; margin-bottom: 22px;
}
.hero-title { font-size: clamp(30px, 5.2vw, 54px); line-height: 1.25; margin-bottom: 20px; font-weight: 800; letter-spacing: 1px; }
.grad-text { background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero-sub { color: var(--muted); font-size: clamp(16px, 2vw, 19px); max-width: 720px; margin-bottom: 34px; }
.hl { color: var(--accent-3); font-weight: 600; }
.hero-actions { display: flex; gap: 16px; flex-wrap: wrap; margin-bottom: 48px; }
.btn {
  display: inline-block; padding: 13px 28px; border-radius: 12px; font-weight: 600;
  font-size: 15px; cursor: pointer; transition: transform .15s, box-shadow .2s; border: none;
}
.btn-primary { background: var(--grad); color: #fff; box-shadow: 0 8px 30px rgba(56,189,248,.35); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 12px 36px rgba(99,102,241,.5); }
.btn-ghost { border: 1px solid var(--border); color: var(--text); background: rgba(15,23,42,.02); }
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); }
.btn-block { width: 100%; }
.hero-stats { display: flex; gap: 48px; flex-wrap: wrap; }
.hstat strong { display: block; font-size: 34px; font-weight: 800; background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hstat span { color: var(--muted); font-size: 14px; }
.hero-split { display: grid; grid-template-columns: 1.1fr 0.9fr; gap: 48px; align-items: center; }
.hero-img img {
  width: 100%; height: 420px; object-fit: cover; border-radius: 20px;
  box-shadow: 0 16px 50px rgba(15,23,42,.18); border: 1px solid var(--border);
}
.scroll-hint { position: absolute; bottom: 26px; left: 50%; transform: translateX(-50%); color: var(--muted); font-size: 13px; animation: float 2.2s ease-in-out infinite; }
@keyframes float { 0%,100% { transform: translate(-50%,0); } 50% { transform: translate(-50%,8px); } }

/* ============ 通用 Section ============ */
.section { padding: 96px 24px; }
.section-alt { background: var(--bg-2); }
.container { max-width: var(--maxw); margin: 0 auto; }
.section-head { text-align: center; margin-bottom: 56px; }
.kicker { display: block; color: var(--accent); font-size: 13px; letter-spacing: 3px; margin-bottom: 10px; text-transform: uppercase; }
.section-head h2 { font-size: clamp(26px, 3.6vw, 38px); font-weight: 800; margin-bottom: 12px; }
.lead { color: var(--muted); font-size: 17px; }

/* ============ 关于 ============ */
.about-grid { display: grid; grid-template-columns: 1.4fr 1fr; gap: 40px; align-items: center; }
.about-text p { color: var(--muted); margin-bottom: 16px; }
.about-text b { color: var(--text); }
.about-list { list-style: none; margin-top: 20px; display: grid; gap: 10px; }
.about-list li { color: var(--text); font-size: 15px; }
.about-card {
  background: var(--card); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 36px; text-align: center; backdrop-filter: blur(8px);
}
.about-card-head { display: flex; align-items: baseline; justify-content: center; gap: 6px; margin-bottom: 4px; }
.big-num { font-size: 72px; font-weight: 800; background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.unit { font-size: 22px; color: var(--accent); font-weight: 700; }
.about-card > p { color: var(--muted); margin-bottom: 24px; }
.about-metrics { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.metric { background: rgba(15,23,42,.03); border: 1px solid var(--border); border-radius: 12px; padding: 18px 10px; }
.metric b { display: block; font-size: 26px; font-weight: 800; }
.metric span { color: var(--muted); font-size: 13px; }
.industry-grid { display: grid; grid-template-columns: 1.2fr 0.8fr; gap: 40px; align-items: center; }
.industry-text p { color: var(--muted); font-size: 15px; line-height: 1.8; margin-bottom: 20px; }
.industry-pains { list-style: none; display: grid; gap: 10px; }
.industry-pains li {
  background: var(--card); border: 1px solid var(--border); border-radius: 10px;
  padding: 12px 16px; font-size: 14.5px; color: var(--text);
}
.industry-pains li::before { content: "⚠ "; color: #f59e0b; }
.industry-img img {
  width: 100%; height: 320px; object-fit: cover; border-radius: 16px;
  box-shadow: 0 12px 40px rgba(15,23,42,.14); border: 1px solid var(--border);
}

/* ============ 产品卡片 ============ */
.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 22px; }
.card {
  background: var(--card); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 30px 26px; transition: transform .2s, border-color .2s, box-shadow .25s;
  backdrop-filter: blur(8px);
}
.card:hover { transform: translateY(-6px); border-color: rgba(56,189,248,.5); box-shadow: 0 16px 40px rgba(37,99,235,.25); }
.card-icon { width: 56px; height: 56px; border-radius: 14px; display: grid; place-items: center; margin-bottom: 18px; color: #fff; }
.card-icon svg { width: 34px; height: 34px; }
.icon-server { background: linear-gradient(135deg,#3b82f6,#6366f1); }
.icon-network { background: linear-gradient(135deg,#06b6d4,#3b82f6); }
.icon-camera { background: linear-gradient(135deg,#8b5cf6,#ec4899); }
.icon-integration { background: linear-gradient(135deg,#22d3ee,#14b8a6); }
.card h3 { font-size: 19px; margin-bottom: 10px; }
.card p { color: var(--muted); font-size: 14.5px; margin-bottom: 16px; }
.tag { display: inline-block; font-size: 12px; color: var(--accent); background: rgba(56,189,248,.1); border: 1px solid var(--border); padding: 4px 10px; border-radius: 999px; }

/* ============ 解决方案 ============ */
.solutions { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 22px; }
.solution {
  background: var(--card); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 28px; position: relative; overflow: hidden; transition: border-color .2s;
}
.solution:hover { border-color: rgba(56,189,248,.5); }
.sol-num { position: absolute; right: 20px; top: 12px; font-size: 48px; font-weight: 800; color: rgba(56,189,248,.15); }
.solution h3 { font-size: 19px; margin-bottom: 10px; color: var(--accent-3); }
.solution p { color: var(--muted); font-size: 14.5px; }

/* ============ 优势 ============ */
.adv-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 22px; }
.adv { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 28px; text-align: center; transition: transform .2s; }
.adv:hover { transform: translateY(-4px); }
.adv-icon { font-size: 34px; display: block; margin-bottom: 14px; }
.adv h3 { font-size: 17px; margin-bottom: 8px; }
.adv p { color: var(--muted); font-size: 14px; }

/* ============ 联系 ============ */
.contact-grid { display: grid; grid-template-columns: 1fr 1.2fr; gap: 32px; align-items: start; }
.contact-info { display: grid; gap: 18px; }
.c-item { display: flex; gap: 16px; align-items: flex-start; background: var(--card); border: 1px solid var(--border); border-radius: 14px; padding: 18px 20px; }
.c-icon { font-size: 22px; }
.c-item b { display: block; margin-bottom: 2px; }
.c-item p { color: var(--muted); font-size: 15px; }
.contact-form { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 28px; display: grid; gap: 14px; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.contact-form input, .contact-form textarea {
  width: 100%; padding: 13px 16px; border-radius: 11px; border: 1px solid var(--border);
  background: #f8fafc; color: var(--text); font-size: 15px; font-family: inherit;
  outline: none; transition: border-color .2s;
}
.contact-form input:focus, .contact-form textarea:focus { border-color: var(--accent); }
.contact-form textarea { resize: vertical; }
.form-note { color: var(--muted); font-size: 13px; text-align: center; }

/* ============ 页脚 ============ */
.footer { background: var(--bg-2); border-top: 1px solid var(--border); padding: 34px 24px; }
.footer-inner { display: flex; align-items: center; justify-content: space-between; gap: 20px; flex-wrap: wrap; }
.footer-brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 17px; }
.footer-text p { color: var(--muted); font-size: 14px; }
.footer-copy { font-size: 12.5px !important; opacity: .7; margin-top: 4px; }

/* ============ 动画（内容默认可见，已移除滚动隐藏避免空白） ============ */
.reveal { opacity: 1; transform: none; }

/* ============ 下载专区 & 在线工具 ============ */
.active-link { color: var(--text) !important; font-weight: 700; }
.hero-sub { min-height: 30vh; }
.dl-group { margin-bottom: 44px; }
.dl-cat { font-size: 20px; margin-bottom: 18px; color: var(--accent-3); }
.dl-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 18px; }
.dl-card {
  display: flex; align-items: center; gap: 16px;
  background: var(--card); border: 1px solid var(--border); border-radius: 14px; padding: 20px;
  transition: transform .2s, border-color .2s;
}
.dl-card:hover { transform: translateY(-4px); border-color: rgba(56,189,248,.5); }
.dl-icon { font-size: 30px; flex-shrink: 0; }
.dl-body { flex: 1; min-width: 0; }
.dl-body h4 { font-size: 16px; margin-bottom: 4px; }
.dl-body p { color: var(--muted); font-size: 13px; line-height: 1.5; }
.dl-meta { margin-top: 8px; }
.dl-size { font-size: 12px; color: var(--accent); background: rgba(56,189,248,.1); border: 1px solid var(--border); padding: 2px 8px; border-radius: 6px; }
.btn-dl { padding: 9px 16px; font-size: 13px; white-space: nowrap; flex-shrink: 0; }

.subnet-wrap { max-width: 720px; margin: 0 auto; }
.subnet-form { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 26px; }
.subnet-form .field { display: grid; gap: 6px; }
.subnet-form label { color: var(--muted); font-size: 13px; }
.subnet-form input {
  width: 100%; padding: 12px 14px; border-radius: 10px; border: 1px solid var(--border);
  background: #f8fafc; color: var(--text); font-size: 15px; outline: none;
  transition: border-color .2s;
}
.subnet-form input:focus { border-color: var(--accent); }
.subnet-form .btn { margin-top: 16px; }
.subnet-result {
  margin-top: 20px; background: var(--card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 8px 22px;
}
.sub-row { display: flex; justify-content: space-between; align-items: center; padding: 12px 0; border-bottom: 1px solid var(--border); }
.sub-row:last-child { border-bottom: none; }
.sub-row span { color: var(--muted); font-size: 14px; }
.sub-row b { font-family: ui-monospace, SFMono-Regular, Menlo, monospace; color: var(--accent-3); font-size: 15px; }
.sub-err { color: #f87171; padding: 16px; text-align: center; }

/* ============ 解决方案详情页 ============ */
.sol-hero { min-height: 30vh; }
.sol-hero-inner { display: grid; grid-template-columns: 1.1fr 0.9fr; gap: 40px; align-items: center; }
.sol-hero-img img {
  width: 100%; height: 280px; object-fit: cover; border-radius: 16px;
  box-shadow: 0 12px 40px rgba(15,23,42,.16); border: 1px solid var(--border);
  display: block;
}
.sol-block { margin-bottom: 44px; }
.sol-h { font-size: 22px; font-weight: 800; margin-bottom: 18px; display: flex; align-items: center; gap: 10px; }
.sol-h::before { content: ""; width: 5px; height: 22px; background: var(--grad); border-radius: 3px; }
.sol-list { list-style: none; display: grid; gap: 14px; }
.sol-list li { display: flex; gap: 14px; align-items: flex-start; background: var(--card); border: 1px solid var(--border); border-radius: 12px; padding: 16px 18px; }
.sol-list .mark { color: #fbbf24; font-size: 18px; flex-shrink: 0; line-height: 1.4; }
.sol-list .num { font-family: ui-monospace, monospace; color: var(--accent); font-weight: 800; font-size: 18px; flex-shrink: 0; }
.sol-list li div { color: var(--text); font-size: 15px; line-height: 1.6; }
.sol-highlights { display: flex; flex-wrap: wrap; gap: 12px; }
.hl-chip { background: rgba(56,189,248,.08); border: 1px solid var(--border); color: var(--accent-3); padding: 9px 16px; border-radius: 999px; font-size: 14px; }
.sol-nav { display: flex; justify-content: center; gap: 14px; flex-wrap: wrap; margin-top: 48px; }
.sol-layout { display: grid; grid-template-columns: 1fr 300px; gap: 36px; align-items: start; }
.sol-side { position: sticky; top: 90px; display: grid; gap: 20px; }
.side-card { background: var(--card); border: 1px solid var(--border); border-radius: 14px; padding: 18px; box-shadow: 0 1px 3px rgba(15,23,42,.06); }
.side-card img { width: 100%; height: 170px; object-fit: cover; border-radius: 10px; }
.side-card h4 { font-size: 16px; margin-bottom: 8px; }
.side-contact p { color: var(--muted); font-size: 13px; margin-bottom: 14px; }
.side-contact .btn { margin-bottom: 14px; }
.side-phone { display: flex; align-items: center; gap: 8px; font-size: 13px; color: var(--muted); }
.side-phone b { color: var(--accent); font-size: 15px; }
.rel-list { display: grid; gap: 8px; }
.rel-link { display: flex; align-items: center; gap: 8px; padding: 8px 10px; border: 1px solid var(--border); border-radius: 8px; color: var(--text); font-size: 14px; transition: border-color .2s; }
.rel-link:hover { border-color: var(--accent); color: var(--accent); }
.sol-arch {
  background: var(--card); border: 1px solid var(--border); border-left: 4px solid var(--accent);
  border-radius: 12px; padding: 18px 20px; color: var(--text); font-size: 15px; line-height: 1.7;
}
.sol-products { display: flex; flex-wrap: wrap; gap: 12px; }
.prod-chip {
  background: rgba(99,102,241,.12); border: 1px solid rgba(99,102,241,.3);
  color: #4f46e5; padding: 9px 16px; border-radius: 999px; font-size: 14px;
}
.topo-wrap {
  background: var(--card); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 16px; overflow-x: auto;
}
.topo-svg { width: 100%; height: auto; display: block; min-width: 560px; }
.topo-band { fill: rgba(2,132,199,0.04); stroke: rgba(2,132,199,0.18); }
.topo-layer { fill: #0284c7; font-size: 13px; font-weight: 700; }
.topo-node { fill: #ffffff; stroke: rgba(2,132,199,0.5); stroke-width: 1.5; }
.topo-node-text { fill: #0f172a; font-size: 12px; }
.topo-line { stroke: rgba(2,132,199,0.4); stroke-width: 1.5; stroke-dasharray: 5 4; }

/* ============ 卡片阴影（浅色主题用） ============ */
.card, .solution, .adv, .c-item, .dl-card, .about-card, .contact-form, .subnet-form, .subnet-result, .metric, .topo-wrap {
  box-shadow: 0 1px 3px rgba(15,23,42,.06);
}

/* ============ 响应式 ============ */
@media (max-width: 860px) {
  .nav-links { display: none; position: absolute; top: 100%; left: 0; right: 0; background: rgba(255,255,255,0.98); flex-direction: column; padding: 16px 24px; gap: 14px; border-bottom: 1px solid var(--border); }
  .nav-links.open { display: flex; }
  .nav-cta { display: none; }
  .nav-toggle { display: block; margin-left: auto; }
  .about-grid, .contact-grid { grid-template-columns: 1fr; }
  .form-row { grid-template-columns: 1fr; }
  .hero-stats { gap: 28px; }
  .sol-hero-inner { grid-template-columns: 1fr; }
  .sol-hero-img { display: none; }
  .hero-split { grid-template-columns: 1fr; }
  .hero-img { display: none; }
  .industry-grid { grid-template-columns: 1fr; }
  .industry-img { display: none; }
  .sol-layout { grid-template-columns: 1fr; }
  .sol-side { position: static; }
}