html { scroll-behavior: smooth; }
body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  grid-template-rows: 52px 1fr auto;
  grid-template-columns: 228px 1fr;
  grid-template-areas:
    "os os"
    "toc stage"
    "foot foot";
  background: #1e293b;
  color: #0f172a;
  font-family: "IBM Plex Sans", "Segoe UI", "Microsoft YaHei", sans-serif;
  line-height: 1.55;
}

.os {
  grid-area: os;
  background: #0f172a;
  color: #e2e8f0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 18px;
  border-bottom: 1px solid #334155;
}
.logo {
  display: flex;
  align-items: center;
  gap: 8px;
  color: #f8fafc;
  text-decoration: none;
  font-weight: 700;
  font-size: 15px;
}
.os-nav { display: flex; gap: 14px; }
.os-nav a {
  color: #94a3b8;
  text-decoration: none;
  font-size: 13px;
  padding: 4px 8px;
  background: #1e293b;
}
.os-nav a:hover { color: #f8fafc; }

.toc {
  grid-area: toc;
  background: #1e293b;
  color: #cbd5e1;
  padding: 18px 14px;
  border-right: 1px solid #334155;
  position: sticky;
  top: 52px;
  align-self: start;
  height: calc(100vh - 52px);
  overflow: auto;
}
.toc p {
  margin: 0 0 10px;
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: #64748b;
}
.toc a {
  display: block;
  color: #cbd5e1;
  text-decoration: none;
  font-size: 13px;
  padding: 7px 8px;
  border-left: 2px solid #334155;
  margin-bottom: 2px;
}
.toc a:hover { border-left-color: #38bdf8; color: #f8fafc; background: #0f172a; }

.stage {
  grid-area: stage;
  background: #f1f5f9;
  padding: 22px 26px 40px;
  min-width: 0;
}

.monitor {
  background: #0f172a;
  padding: 12px 12px 18px;
  border-radius: 10px 10px 6px 6px;
  box-shadow: 0 18px 0 -8px #334155, 0 22px 0 -8px #475569;
  margin-bottom: 28px;
}
.monitor-bar {
  height: 10px;
  display: flex;
  gap: 5px;
  align-items: center;
  margin-bottom: 10px;
}
.monitor-bar i {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #64748b;
  display: block;
}
.screen {
  background: #f8fafc;
  padding: 28px 26px 24px;
}
.screen h1 {
  margin: 0 0 12px;
  font-size: 30px;
  line-height: 1.3;
}
.screen p { margin: 0 0 10px; color: #334155; max-width: 48em; }
.btn {
  display: inline-block;
  margin-top: 8px;
  background: #1e293b;
  color: #f8fafc;
  text-decoration: none;
  padding: 10px 18px;
  font-weight: 650;
  font-size: 14px;
}
.btn:hover { background: #0f172a; }

.block { margin-bottom: 34px; }
.block h2 {
  margin: 0 0 10px;
  font-size: 22px;
  line-height: 1.35;
}
.note { margin: 0 0 14px; color: #475569; }

.two {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}
.tile {
  background: #fff;
  border: 1px solid #cbd5e1;
  padding: 14px 14px 12px;
  display: grid;
  grid-template-columns: 28px 1fr;
  gap: 10px;
}
.tile h3 { margin: 0 0 6px; font-size: 16px; }
.tile p { margin: 0; color: #475569; font-size: 14px; }

.bezel {
  border: 10px solid #1e293b;
  background: #fff;
  padding: 16px 12px;
  box-shadow: inset 0 0 0 1px #94a3b8;
}
.steps4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
}
.steps4 article {
  background: #f8fafc;
  border-top: 3px solid #38bdf8;
  padding: 10px;
}
.steps4 b { display: block; font-size: 12px; color: #0369a1; margin-bottom: 4px; }
.steps4 p { margin: 0; font-size: 13.5px; color: #334155; }

.dual {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}
.display {
  background: #1e293b;
  padding: 8px 8px 14px;
}
.display .inner {
  background: #fff;
  min-height: 180px;
  padding: 14px;
}
.display h3 { margin: 0 0 8px; font-size: 16px; }
.display ul { margin: 0; padding-left: 18px; color: #334155; font-size: 14px; }
.display li { margin-bottom: 6px; }

.pair {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}
.pair article {
  background: #fff;
  padding: 14px;
  border-left: 4px solid #1e293b;
}
.pair p { margin: 0 0 8px; color: #475569; font-size: 14.5px; }

.faq-compact { background: #fff; border: 1px solid #cbd5e1; }
.faq-compact details {
  border-bottom: 1px solid #e2e8f0;
  padding: 10px 14px;
}
.faq-compact details:last-child { border-bottom: 0; }
.faq-compact summary {
  cursor: pointer;
  font-weight: 650;
  font-size: 14.5px;
}
.faq-compact p { margin: 8px 0 0; color: #475569; font-size: 14px; }

.foot {
  grid-area: foot;
  background: #0f172a;
  color: #94a3b8;
  padding: 18px 24px;
  font-size: 12.5px;
}
.foot p { margin: 0 0 6px; }

@media (max-width: 900px) {
  body {
    grid-template-columns: 1fr;
    grid-template-areas:
      "os"
      "stage"
      "foot";
  }
  .toc { display: none; }
  .two, .dual, .pair, .steps4 { grid-template-columns: 1fr; }
  .screen h1 { font-size: 24px; }
}

#news .news-list { display: grid; gap: 12px; }
#news article { display: grid; grid-template-columns: 88px 1fr; background: #0f172a; color: #e2e8f0; border: 1px solid #334155; }
#news time { padding: 14px 10px; background: #1e293b; color: #38bdf8; font-size: 12px; }
#news h3 { margin: 12px 14px 4px; font-size: 15px; color: #f8fafc; }
#news p { margin: 0 14px 14px; font-size: 13px; color: #94a3b8; }
@media (max-width: 700px) { #news article { grid-template-columns: 1fr; } }