/* ==========================================================================
   Xiaojin Technology Studio — site stylesheet
   Design language: technical schematic / network topology datasheet.
   ========================================================================== */

:root{
  --paper:      #EEF1F0;
  --panel:      #FFFFFF;
  --ink:        #12181B;
  --ink-soft:   #4A555B;
  --ink-faint:  #7C878C;
  --line:       #C7CFD2;
  --line-soft:  #DCE2E3;
  --signal:     #1F5673;
  --signal-2:   #2E7D7B;
  --amber:      #C97A2B;
  --radius:     2px;

  --font-display: 'Space Grotesk', sans-serif;
  --font-body:    'IBM Plex Sans', sans-serif;
  --font-mono:    'IBM Plex Mono', monospace;
}

*{ box-sizing: border-box; }
html{ scroll-behavior: smooth; }

body{
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

img, svg{ display: block; max-width: 100%; }

a{ color: inherit; text-decoration: none; }

.wrap{
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 28px;
}

/* -------------------------------------------------- typography -------- */

h1, h2, h3{
  font-family: var(--font-display);
  font-weight: 600;
  letter-spacing: -0.01em;
  margin: 0;
}

.eyebrow{
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--signal);
}

.lede{
  color: var(--ink-soft);
  font-size: 1.05rem;
  max-width: 56ch;
}

/* -------------------------------------------------- header ------------ */

.site-header{
  border-bottom: 1px solid var(--line);
  background: var(--paper);
  position: sticky;
  top: 0;
  z-index: 20;
}

.site-header .wrap{
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 18px;
  padding-bottom: 18px;
  gap: 20px;
}

.brand{
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1.05rem;
  color: var(--ink);
}

.brand-mark{
  width: 30px;
  height: 30px;
  flex: none;
}

.brand-sub{
  display: block;
  font-family: var(--font-mono);
  font-size: 10.5px;
  font-weight: 400;
  letter-spacing: 0.04em;
  color: var(--ink-faint);
}

.site-nav{
  display: flex;
  flex-wrap: wrap;
  gap: 22px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.03em;
}

.site-nav a{
  color: var(--ink-soft);
  border-bottom: 1px solid transparent;
  padding-bottom: 2px;
  transition: color .15s ease, border-color .15s ease;
}

.site-nav a:hover,
.site-nav a[aria-current="page"]{
  color: var(--signal);
  border-color: var(--signal);
}

/* -------------------------------------------------- hero -------------- */

.hero{
  padding: 64px 0 40px;
  border-bottom: 1px solid var(--line);
}

.hero .wrap{
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 40px;
  align-items: center;
}

.hero h1{
  font-size: clamp(2.1rem, 4vw, 2.85rem);
  line-height: 1.08;
  margin-top: 14px;
  margin-bottom: 18px;
}

.hero .lede{ margin-bottom: 26px; }

.hero-meta{
  display: flex;
  gap: 28px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--ink-faint);
  border-top: 1px solid var(--line-soft);
  padding-top: 16px;
  margin-top: 30px;
}

.hero-meta strong{
  display: block;
  color: var(--ink);
  font-size: 13px;
  font-weight: 500;
}

/* -------------------------------------------------- topology diagram -- */

.topology{ width: 100%; height: auto; }

.topo-line{
  fill: none;
  stroke: var(--line);
  stroke-width: 1.2;
}

.topo-line.live{
  stroke: var(--signal-2);
  stroke-dasharray: 4 260;
  animation: flow 7s linear infinite;
}

@keyframes flow{
  to{ stroke-dashoffset: -264; }
}

.topo-core circle{ fill: var(--ink); }
.topo-core text{
  font-family: var(--font-mono);
  font-size: 9px;
  fill: var(--paper);
  text-anchor: middle;
}

.topo-node{
  cursor: pointer;
}
.topo-node circle.dot{
  fill: var(--panel);
  stroke: var(--ink);
  stroke-width: 1.2;
  transition: fill .15s ease, stroke .15s ease;
}
.topo-node:hover circle.dot{
  fill: var(--signal);
  stroke: var(--signal);
}
.topo-node text{
  font-family: var(--font-mono);
  font-size: 10.5px;
  fill: var(--ink-soft);
  transition: fill .15s ease;
}
.topo-node:hover text{ fill: var(--signal); }
.topo-node .idx{
  font-size: 9px;
  fill: var(--amber);
}

@media (prefers-reduced-motion: reduce){
  .topo-line.live{ animation: none; }
}

/* -------------------------------------------------- capability index -- */

.section{ padding: 56px 0; }
.section + .section{ border-top: 1px solid var(--line); }

.section-head{
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  gap: 20px;
  margin-bottom: 30px;
  flex-wrap: wrap;
}

.index-grid{
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.index-card{
  background: var(--panel);
  padding: 26px 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
  transition: background .15s ease;
}

.index-card:hover{ background: #F7FAF9; }

.index-card .idx{
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--amber);
}

.index-card h3{
  font-size: 1.05rem;
}

.index-card p{
  color: var(--ink-soft);
  font-size: 0.92rem;
  margin: 0;
  flex: 1;
}

.index-card .go{
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--signal);
  display: inline-flex;
  align-items: center;
  gap: 6px;
}
.index-card:hover .go{ text-decoration: underline; }

/* -------------------------------------------------- about strip ------- */

.about-strip .wrap{
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
}

.about-strip p{ color: var(--ink-soft); }

.spec-list{
  list-style: none;
  margin: 0;
  padding: 0;
  font-family: var(--font-mono);
  font-size: 12.5px;
  border-top: 1px solid var(--line-soft);
}

.spec-list li{
  display: flex;
  justify-content: space-between;
  gap: 12px;
  padding: 10px 0;
  border-bottom: 1px solid var(--line-soft);
  color: var(--ink-soft);
}

.spec-list li span:first-child{ color: var(--ink-faint); }
.spec-list li span:last-child{ color: var(--ink); text-align: right; }

/* -------------------------------------------------- category page ----- */

.cat-hero{
  padding: 46px 0 38px;
  border-bottom: 1px solid var(--line);
}

.cat-hero .breadcrumb{
  font-family: var(--font-mono);
  font-size: 11.5px;
  color: var(--ink-faint);
  margin-bottom: 16px;
}
.cat-hero .breadcrumb a{ color: var(--signal); }

.cat-hero-top{
  display: flex;
  gap: 24px;
  align-items: flex-start;
  justify-content: space-between;
  flex-wrap: wrap;
}

.cat-hero h1{
  font-size: clamp(1.8rem, 3.4vw, 2.35rem);
  margin: 10px 0 14px;
}

.cat-icon{ width: 64px; height: 64px; flex: none; }
.cat-icon .s{ fill: none; stroke: var(--signal); stroke-width: 1.4; }
.cat-icon .f{ fill: var(--ink); }
.cat-icon .a{ fill: var(--amber); }

.service-table{
  border-top: 1px solid var(--line);
}

.service-row{
  display: grid;
  grid-template-columns: 64px 1fr;
  gap: 24px;
  padding: 26px 0;
  border-bottom: 1px solid var(--line);
  align-items: start;
}

.service-row .num{
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--amber);
  padding-top: 3px;
}

.service-row h3{
  font-size: 1.05rem;
  margin-bottom: 8px;
}

.service-row p{
  color: var(--ink-soft);
  font-size: 0.93rem;
  margin: 0;
  max-width: 62ch;
}

@media (max-width: 640px){
  .service-row{
    grid-template-columns: 40px 1fr;
  }
}

/* -------------------------------------------------- cross-links ------- */

.cross-nav{
  padding: 44px 0;
  border-top: 1px solid var(--line);
}

.cross-nav .index-grid .index-card{ padding: 20px 22px; }

/* -------------------------------------------------- footer ------------ */

.site-footer{
  border-top: 1px solid var(--line);
  background: var(--ink);
  color: #C9D2D4;
  padding: 46px 0 30px;
}

.site-footer .wrap{
  display: grid;
  grid-template-columns: 1.2fr 1fr 1fr;
  gap: 36px;
}

.site-footer h4{
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: #7C8A8D;
  margin: 0 0 14px;
  font-weight: 500;
}

.footer-record{
  font-family: var(--font-mono);
  font-size: 12.5px;
  line-height: 1.9;
}

.footer-record .legal-cn{ color: #EDEFEE; }
.footer-record .legal-en{ color: #A9B4B6; }

.footer-nav{
  display: flex;
  flex-direction: column;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 12.5px;
}
.footer-nav a{ color: #C9D2D4; }
.footer-nav a:hover{ color: #fff; }

.footer-bottom{
  max-width: 1080px;
  margin: 34px auto 0;
  padding: 18px 28px 0;
  border-top: 1px solid #2A3336;
  font-family: var(--font-mono);
  font-size: 11px;
  color: #6D7A7D;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 10px;
}

@media (max-width: 780px){
  .hero .wrap{ grid-template-columns: 1fr; }
  .about-strip .wrap{ grid-template-columns: 1fr; }
  .site-footer .wrap{ grid-template-columns: 1fr; gap: 26px; }
  .site-nav{ gap: 14px 18px; }
}