/* ===== tokens ===== */
:root{
  --blueprint: #123A63;
  --blueprint-deep: #0A2A4A;
  --blueprint-darker: #071D33;
  --line-cyan: #8FD3F4;
  --line-cyan-dim: rgba(143,211,244,.32);
  --line-cyan-faint: rgba(143,211,244,.14);
  --paper: #EAF3F8;
  --paper-dim: #D6E4EC;
  --ink: #0B2A48;
  --graphite: #4C6478;
  --copper: #E2963C;
  --copper-deep: #C97C25;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Roboto, Helvetica, Arial, sans-serif;
  --mono: ui-monospace, "SF Mono", Menlo, Consolas, "Cascadia Mono", monospace;
}

*,*::before,*::after{ box-sizing:border-box; }
html{ scroll-behavior:smooth; }
body{
  margin:0;
  font-family:var(--sans);
  background:var(--blueprint);
  color:var(--paper);
  line-height:1.7;
  -webkit-font-smoothing:antialiased;
}
h1,h2,h3{ font-family:var(--sans); font-weight:800; letter-spacing:-.01em; margin:0; }
p{ margin:0; }
a{ color:inherit; }
ul{ margin:0; padding:0; list-style:none; }
table{ border-collapse:collapse; width:100%; }
.wrap{ max-width:1120px; margin:0 auto; padding:0 24px; }

/* i18n toggle: default zh visible, en hidden */
html[data-lang="zh"] .t.en{ display:none; }
html[data-lang="en"] .t.zh{ display:none; }

.skip-link{
  position:absolute; left:-999px; top:0; background:var(--copper); color:var(--ink);
  padding:10px 16px; z-index:200; border-radius:0 0 6px 0;
}
.skip-link:focus{ left:0; }

/* ===== header ===== */
.site-header{
  position:sticky; top:0; z-index:100;
  background:rgba(10,42,74,.92);
  backdrop-filter:blur(6px);
  border-bottom:1px solid var(--line-cyan-dim);
}
.bar{
  max-width:1120px; margin:0 auto; padding:14px 24px;
  display:flex; align-items:center; gap:24px;
}
.wordmark{ display:flex; align-items:center; gap:10px; text-decoration:none; color:var(--paper); }
.mark{ width:26px; height:26px; color:var(--copper); flex:none; }
.wordmark-text{ font-weight:800; letter-spacing:.02em; font-size:15px; }
.footer-inner .wordmark-text{ font-size:13px; letter-spacing:.06em; color:var(--line-cyan); }

.main-nav{ display:flex; gap:22px; margin-left:8px; flex:1; }
.main-nav a{
  font-size:14px; text-decoration:none; color:var(--line-cyan);
  opacity:.85; white-space:nowrap;
}
.main-nav a:hover{ opacity:1; color:var(--paper); }

.header-tools{ display:flex; align-items:center; gap:16px; }
.tel{ font-family:var(--mono); font-size:13px; color:var(--paper); text-decoration:none; opacity:.9; white-space:nowrap; }
.tel:hover{ opacity:1; }

.lang-switch{ background:none; border:none; padding:0; cursor:pointer; }
.lang-switch-track{
  position:relative; display:flex; align-items:center;
  width:64px; height:28px; border-radius:14px;
  background:var(--blueprint-darker); border:1px solid var(--line-cyan-dim);
  font-family:var(--mono); font-size:11px; font-weight:700;
}
.lang-switch-opt{
  position:relative; z-index:2; flex:1; text-align:center; color:var(--line-cyan); pointer-events:none;
}
html[data-lang="en"] .lang-switch-opt[data-set="en"],
html[data-lang="zh"] .lang-switch-opt[data-set="zh"]{ color:var(--ink); }
.lang-switch-knob{
  position:absolute; top:2px; left:2px; width:30px; height:22px; border-radius:11px;
  background:var(--copper); transition:transform .2s ease; z-index:1;
}
html[data-lang="en"] .lang-switch-knob{ transform:translateX(30px); }

/* ===== hero ===== */
.hero{
  position:relative; overflow:hidden;
  padding:64px 0 40px;
  background:
    radial-gradient(ellipse 900px 500px at 15% -10%, rgba(143,211,244,.14), transparent 60%),
    var(--blueprint);
}
.grid-overlay{
  position:absolute; inset:0; pointer-events:none;
  background-image:
    linear-gradient(var(--line-cyan-faint) 1px, transparent 1px),
    linear-gradient(90deg, var(--line-cyan-faint) 1px, transparent 1px);
  background-size:40px 40px;
  mask-image:linear-gradient(180deg, rgba(0,0,0,.9), transparent 85%);
}
.hero-inner{ position:relative; z-index:1; padding-top:24px; }
.eyebrow{
  font-family:var(--mono); font-size:12px; letter-spacing:.14em; text-transform:uppercase;
  color:var(--copper); margin-bottom:18px;
}
.hero-title{
  font-size:clamp(32px, 5.4vw, 58px); line-height:1.12; color:#fff;
  max-width:16ch;
}
.hero-sub{
  margin-top:22px; max-width:56ch; color:var(--line-cyan); font-size:16px; opacity:.92;
}
.hero-cta{ display:flex; gap:14px; margin-top:32px; flex-wrap:wrap; }

.btn{
  display:inline-flex; align-items:center; justify-content:center;
  padding:12px 22px; border-radius:6px; font-weight:700; font-size:14px;
  text-decoration:none; border:1px solid transparent; white-space:nowrap;
}
.btn-primary{ background:var(--copper); color:var(--blueprint-darker); }
.btn-primary:hover{ background:var(--copper-deep); }
.btn-ghost{ border-color:var(--line-cyan-dim); color:var(--paper); }
.btn-ghost:hover{ border-color:var(--line-cyan); background:rgba(143,211,244,.08); }

/* ===== single-line diagram (signature element) ===== */
.sld{ position:relative; z-index:1; margin-top:64px; padding-bottom:8px; }
.sld-caption{
  font-family:var(--mono); font-size:11px; letter-spacing:.12em; text-transform:uppercase;
  color:var(--line-cyan); opacity:.7; margin-bottom:22px;
}
.sld-rail{
  position:relative; display:flex; justify-content:space-between; gap:8px;
  padding-top:17px;
}
.sld-line{
  position:absolute; top:17px; left:17px; right:17px; height:2px;
  background:var(--line-cyan-dim); z-index:0;
}
.pulse{
  position:absolute; top:-3px; width:8px; height:8px; border-radius:50%;
  background:var(--copper); box-shadow:0 0 10px 2px rgba(226,150,60,.7);
  left:0; opacity:0;
  animation:travel 6s linear infinite;
}
.pulse.p2{ animation-delay:2s; }
.pulse.p3{ animation-delay:4s; }
@keyframes travel{
  0%{ left:0%; opacity:0; }
  6%{ opacity:1; }
  94%{ opacity:1; }
  100%{ left:calc(100% - 8px); opacity:0; }
}

.sld-node{
  position:relative; z-index:1; flex:1; display:flex; flex-direction:column;
  align-items:center; text-align:center; gap:8px; min-width:0;
}
.node-label{ font-size:13px; color:var(--paper); font-weight:600; }
.node-spec{ font-family:var(--mono); font-size:11px; color:var(--line-cyan); opacity:.8; }
.sld-note{ margin-top:20px; font-size:12px; color:var(--line-cyan); opacity:.6; max-width:60ch; }

/* schematic node glyphs — abstract standardized symbols, not illustrations */
.node-glyph{
  width:34px; height:34px; flex:none; border-radius:50%;
  border:2px solid var(--line-cyan); background:var(--blueprint-deep);
  position:relative; display:flex; align-items:center; justify-content:center;
}
.node-glyph.lg{ width:44px; height:44px; }
.node-glyph.sun::before{
  content:""; width:12px; height:12px; border-radius:50%;
  background:var(--copper); box-shadow:0 0 8px var(--copper);
}
.node-glyph.panel{ border-radius:5px; }
.node-glyph.panel::before{
  content:""; width:20px; height:20px;
  background-image:linear-gradient(var(--line-cyan) 1px, transparent 1px), linear-gradient(90deg, var(--line-cyan) 1px, transparent 1px);
  background-size:7px 7px; opacity:.8;
}
.node-glyph.inverter::before{
  content:""; width:18px; height:10px;
  border-bottom:2px solid var(--line-cyan);
  clip-path:polygon(0% 100%, 15% 100%, 35% 0%, 65% 100%, 85% 0%, 100% 0%, 100% 100%, 0% 100%);
  background:var(--line-cyan);
}
.node-glyph.battery{ border-radius:5px; }
.node-glyph.battery::before{
  content:"+ –"; font-family:var(--mono); font-size:10px; letter-spacing:3px; color:var(--line-cyan);
}
.node-glyph.grid::before{
  content:""; width:16px; height:16px;
  background:
    linear-gradient(45deg, transparent 46%, var(--line-cyan) 46%, var(--line-cyan) 54%, transparent 54%),
    linear-gradient(-45deg, transparent 46%, var(--line-cyan) 46%, var(--line-cyan) 54%, transparent 54%);
}
.node-glyph.home{ border-radius:5px; }
.node-glyph.home::before{
  content:""; width:0; height:0;
  border-left:10px solid transparent; border-right:10px solid transparent;
  border-bottom:10px solid var(--line-cyan);
}
.node-glyph.factory{ border-radius:5px; }
.node-glyph.factory::before{
  content:""; width:20px; height:12px;
  clip-path:polygon(0% 100%,0% 40%,25% 70%,25% 30%,50% 60%,50% 20%,75% 50%,75% 0%,100% 30%,100% 100%);
  background:var(--line-cyan);
}
.node-glyph.tower::before{
  content:""; width:16px; height:20px;
  clip-path:polygon(50% 0%, 65% 40%, 100% 55%, 70% 60%, 80% 100%, 50% 75%, 20% 100%, 30% 60%, 0% 55%, 35% 40%);
  background:var(--line-cyan);
}
.node-glyph.offgrid{ border-radius:50%; }
.node-glyph.offgrid::before{
  content:""; width:22px; height:22px; border-radius:50%;
  border:2px solid var(--line-cyan);
  background:linear-gradient(45deg, transparent 47%, var(--copper) 47%, var(--copper) 53%, transparent 53%);
}

/* ===== about strip ===== */
.about-strip{ background:var(--blueprint-deep); border-top:1px solid var(--line-cyan-dim); border-bottom:1px solid var(--line-cyan-dim); padding:56px 0; }
.about-inner{ display:grid; grid-template-columns:1.3fr 1fr; gap:48px; align-items:start; }
.section-kicker{ font-size:22px; margin-bottom:14px; color:#fff; }
.about-col p{ color:var(--line-cyan); opacity:.92; max-width:60ch; }
.about-facts{ margin:0; display:grid; gap:16px; }
.about-facts > div{ border-left:2px solid var(--copper); padding-left:14px; }
.about-facts dt{ font-family:var(--mono); font-size:11px; letter-spacing:.08em; text-transform:uppercase; color:var(--copper); }
.about-facts dd{ margin:4px 0 0; font-size:14px; color:#fff; }

/* ===== section headers ===== */
.section-title{ font-size:clamp(24px,3.4vw,34px); color:#fff; }
.section-lede{ margin-top:10px; color:var(--line-cyan); opacity:.9; max-width:60ch; }

/* ===== products ===== */
.products{ padding:80px 0; }
.plate-grid{ margin-top:40px; display:grid; grid-template-columns:repeat(3,1fr); gap:24px; }
.plate{
  position:relative; background:var(--paper); color:var(--ink); border-radius:8px;
  padding:26px 24px 24px; display:flex; flex-direction:column; gap:16px;
}
.plate::before,.plate::after{
  content:""; position:absolute; top:10px; width:6px; height:6px; border-radius:50%;
  background:var(--paper-dim); box-shadow:inset 0 1px 2px rgba(11,42,72,.35);
}
.plate::before{ left:10px; }
.plate::after{ right:10px; }
.plate-head{ display:flex; align-items:center; gap:12px; }
.plate-head .node-glyph{ border-color:var(--ink); background:var(--paper-dim); }
.plate-head h3{ font-size:19px; color:var(--ink); }
.plate-desc{ color:var(--graphite); font-size:14px; }
.spec-table{ font-size:13px; }
.spec-table th{ text-align:left; font-weight:600; color:var(--graphite); padding:7px 8px 7px 0; width:40%; border-top:1px solid var(--paper-dim); }
.spec-table td{ font-family:var(--mono); padding:7px 0; border-top:1px solid var(--paper-dim); color:var(--ink); }
.plate-link{
  margin-top:auto; font-weight:700; font-size:13px; text-decoration:none; color:var(--copper-deep);
}
.plate-link:hover{ color:var(--ink); }

/* ===== capability ===== */
.capability{ padding:80px 0; background:var(--blueprint-deep); border-top:1px solid var(--line-cyan-dim); border-bottom:1px solid var(--line-cyan-dim); }
.capability-table{ margin-top:36px; font-size:14px; }
.capability-table th{
  text-align:left; font-family:var(--mono); font-size:11px; letter-spacing:.08em; text-transform:uppercase;
  color:var(--copper); padding:10px 16px; border-bottom:1px solid var(--line-cyan-dim);
}
.capability-table td{ padding:14px 16px; border-bottom:1px solid var(--line-cyan-faint); color:var(--paper); vertical-align:top; }
.capability-table td:first-child{ font-weight:700; color:#fff; width:22%; white-space:nowrap; }
.capability-table tr:hover td{ background:rgba(143,211,244,.05); }

/* ===== applications ===== */
.applications{ padding:80px 0; }
.app-grid{ margin-top:36px; display:grid; grid-template-columns:repeat(4,1fr); gap:20px; }
.app-card{
  border:1px solid var(--line-cyan-dim); border-radius:8px; padding:22px 18px;
  display:flex; flex-direction:column; gap:10px; align-items:flex-start;
}
.app-card .node-glyph{ margin-bottom:4px; }
.app-card h3{ font-size:15px; color:#fff; }
.app-card p{ font-size:13px; color:var(--line-cyan); opacity:.85; }

/* ===== contact ===== */
.contact{ padding:80px 0 96px; }
.terminal-block{
  margin-top:36px; display:grid; grid-template-columns:1fr 1fr; gap:0;
  border:1px solid var(--line-cyan-dim); border-radius:8px; overflow:hidden;
  background:var(--blueprint-deep);
  background-image:repeating-linear-gradient(90deg, var(--line-cyan-dim) 0 2px, transparent 2px 26px);
  background-position:top; background-repeat:no-repeat; background-size:100% 3px;
}
.terminal-col{ padding:32px; }
.terminal-col:first-child{ border-right:1px solid var(--line-cyan-dim); }
.terminal-col h3{ font-size:16px; color:#fff; margin-bottom:18px; }
.term-list{ display:grid; gap:14px; }
.term-list li{ display:flex; flex-direction:column; gap:2px; }
.term-label{ font-family:var(--mono); font-size:11px; letter-spacing:.08em; text-transform:uppercase; color:var(--copper); }
.term-list a{ text-decoration:none; color:var(--paper); font-size:15px; }
.term-list a:hover{ color:var(--line-cyan); }
.term-list span{ color:var(--paper); font-size:14px; }
.cta{ margin-top:24px; }
.checklist{ display:grid; gap:12px; }
.checklist li{
  position:relative; padding-left:20px; font-size:14px; color:var(--paper); opacity:.92;
}
.checklist li::before{
  content:""; position:absolute; left:0; top:7px; width:8px; height:8px;
  border:1.5px solid var(--copper); border-radius:2px;
}

/* ===== footer ===== */
.site-footer{ background:var(--blueprint-darker); padding:36px 0; }
.footer-inner{ display:flex; justify-content:space-between; align-items:center; gap:24px; flex-wrap:wrap; }
.footer-legal{ margin-top:8px; font-size:12px; color:var(--line-cyan); opacity:.65; max-width:52ch; }
.footer-copy{ font-size:12px; color:var(--line-cyan); opacity:.6; }

/* ===== responsive ===== */
@media (max-width:900px){
  .main-nav{ display:none; }
  .about-inner{ grid-template-columns:1fr; }
  .plate-grid{ grid-template-columns:1fr; }
  .app-grid{ grid-template-columns:repeat(2,1fr); }
  .terminal-block{ grid-template-columns:1fr; }
  .terminal-col:first-child{ border-right:none; border-bottom:1px solid var(--line-cyan-dim); }
  .sld-rail{ flex-wrap:wrap; row-gap:28px; }
  .sld-line{ display:none; }
  .pulse{ display:none; }
  .sld-node{ flex:1 1 30%; }
}
@media (max-width:520px){
  .app-grid{ grid-template-columns:1fr; }
  .capability-table td:first-child{ white-space:normal; width:auto; }
  .header-tools .tel{ display:none; }
}

@media (prefers-reduced-motion:reduce){
  html{ scroll-behavior:auto; }
  .pulse{ animation:none; opacity:.9; }
}