/* 第1套根域名 · 工程蓝图 Blueprint：深蓝底 + 青蓝描线 + 图纸网格 + 右下角图签 */
:root {
  --bg: #0b1f33;
  --paper: #0e2a44;
  --line: #3ec6ff;
  --ink: #d7eef8;
  --accent: #ffc857;
  --muted: #7aa8bc;
  --line-dim: rgba(62, 198, 255, 0.28);
  --line-soft: rgba(62, 198, 255, 0.14);
  --ink-strong: #f3fbff;
  --head: #071624;
  --safe: #8fe3b0;
  --mono: Consolas, "Courier New", monospace;
  --sans: "Microsoft YaHei", "PingFang SC", sans-serif;
  --max: 1120px;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: auto; }
body {
  margin: 0;
  color: var(--ink);
  background-color: var(--bg);
  background-image:
    linear-gradient(var(--line-soft) 1px, transparent 1px),
    linear-gradient(90deg, var(--line-soft) 1px, transparent 1px);
  background-size: 24px 24px;
  font-family: var(--sans);
  font-size: 16.5px;
  line-height: 1.8;
}
img, svg { max-width: 100%; display: inline-block; vertical-align: middle; }
a { color: var(--line); text-decoration: none; }
a:hover { color: var(--accent); text-decoration: underline; }
p { margin: 0 0 0.95rem; }
h1, h2, h3 { color: var(--ink-strong); line-height: 1.35; }
h1 { font-size: clamp(1.55rem, 3vw, 2.15rem); margin: 0 0 1rem; }
h2 { font-size: clamp(1.2rem, 2.2vw, 1.45rem); margin: 0 0 0.85rem; }
h3 { font-size: 1.05rem; margin: 0 0 0.45rem; color: var(--line); }
ul, ol { margin: 0 0 1rem; padding-left: 1.3rem; }
li + li { margin-top: 0.35rem; }

.wrap { width: min(var(--max), calc(100% - 2rem)); margin: 0 auto; }

/* —— 图纸标题栏 —— */
.sheet-head {
  background: var(--head);
  border-bottom: 2px solid var(--line);
  position: sticky;
  top: 0;
  z-index: 40;
}
.sheet-head__bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  min-height: 62px;
}
.sheet-head__meta {
  border-top: 1px solid var(--line-dim);
  color: var(--muted);
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  padding: 0.28rem 0;
}
.sheet-head__meta .wrap {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  color: var(--ink-strong);
  font-weight: 700;
  letter-spacing: 0.04em;
  text-decoration: none;
}
.brand:hover { color: var(--line); text-decoration: none; }
.brand svg {
  width: 30px;
  height: 30px;
  color: var(--line);
  border: 1px solid var(--line);
  padding: 3px;
}
.nav { display: flex; gap: 0.2rem; }
.nav a {
  color: var(--ink);
  text-decoration: none;
  padding: 0.42rem 0.85rem;
  border: 1px solid transparent;
  font-size: 0.92rem;
}
.nav a:hover {
  color: var(--line);
  border-color: var(--line);
  text-decoration: none;
}
.nav a.is-on,
.nav a[aria-current="page"] {
  color: var(--head);
  background: var(--line);
  border-color: var(--line);
}
.nav-toggle {
  display: none;
  background: transparent;
  border: 1px solid var(--line);
  color: var(--line);
  padding: 0.28rem 0.42rem;
  cursor: pointer;
}
.nav-toggle svg { width: 18px; height: 18px; }

/* —— 超大图框 + 右下角图签 —— */
.hero-frame {
  position: relative;
  margin: 1.4rem 0 1.7rem;
  background: var(--paper);
  border: 1px solid var(--line);
  box-shadow:
    0 0 0 6px var(--bg),
    0 0 0 7px var(--line-dim);
  padding: 1.35rem 1.4rem 1.5rem;
}
.hero-frame::before,
.hero-frame::after {
  content: "";
  position: absolute;
  width: 16px;
  height: 16px;
  border-color: var(--line);
  border-style: solid;
  pointer-events: none;
}
.hero-frame::before { top: 7px; left: 7px; border-width: 2px 0 0 2px; }
.hero-frame::after { top: 7px; right: 7px; border-width: 2px 2px 0 0; }
.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.45fr) minmax(240px, 0.7fr);
  gap: 1.2rem;
  align-items: stretch;
}
.hero-copy .kicker {
  font-family: var(--mono);
  color: var(--accent);
  letter-spacing: 0.14em;
  font-size: 0.78rem;
  margin-bottom: 0.45rem;
}
.stamp {
  border: 1px solid var(--line);
  background: #0b243c;
  display: flex;
  flex-direction: column;
  align-self: end;
}
.stamp__cap {
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--accent);
  padding: 0.5rem 0.75rem;
  border-bottom: 1px solid var(--line-dim);
}
.stamp table { width: 100%; border-collapse: collapse; font-size: 0.86rem; }
.stamp th,
.stamp td {
  border-top: 1px solid var(--line-dim);
  padding: 0.42rem 0.7rem;
  text-align: left;
  vertical-align: top;
}
.stamp th {
  width: 4.6rem;
  color: var(--muted);
  font-family: var(--mono);
  font-weight: 400;
  font-size: 0.75rem;
  letter-spacing: 0.06em;
}
.stamp td { color: var(--ink-strong); }

/* —— 带编号图框 —— */
.frame {
  position: relative;
  background: var(--paper);
  border: 1px solid var(--line-dim);
  margin: 0 0 1.35rem;
  padding: 1.2rem 1.25rem 1.3rem;
}
.frame > h2 {
  display: flex;
  align-items: flex-start;
  gap: 0.65rem;
  padding-bottom: 0.7rem;
  margin-bottom: 0.9rem;
  border-bottom: 1px dashed var(--line);
}
.frame-no {
  flex: 0 0 auto;
  font-family: var(--mono);
  color: var(--accent);
  font-size: 0.86rem;
  letter-spacing: 0.08em;
  border: 1px solid var(--accent);
  padding: 0.08rem 0.4rem;
  margin-top: 0.18rem;
}
.lede { font-size: 1.02rem; }
.cols {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.9rem;
  margin: 0.2rem 0 1rem;
}
.cell {
  border: 1px solid var(--line-dim);
  background: rgba(11, 31, 51, 0.45);
  padding: 0.9rem 0.95rem 1rem;
}
.cell h3 { display: flex; align-items: center; gap: 0.4rem; }
.cell svg { width: 18px; height: 18px; color: var(--line); flex: 0 0 auto; }
.full { margin-top: 0.15rem; }

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  margin: 0.25rem 0.45rem 0.25rem 0;
  padding: 0.62rem 1.05rem;
  background: var(--accent);
  color: #132033;
  font-weight: 700;
  border: 1px solid var(--accent);
  text-decoration: none;
}
.btn svg { width: 16px; height: 16px; }
.btn:hover { background: #ffd67a; color: #0b1f33; text-decoration: none; }
.btn--ghost {
  background: transparent;
  color: var(--line);
  border-color: var(--line);
}
.btn--ghost:hover { background: rgba(62, 198, 255, 0.12); color: var(--ink-strong); }

/* 评价 / 平台 / 数据 / 对照 */
.quotes { display: grid; gap: 0.75rem; }
.quote {
  display: grid;
  grid-template-columns: 8.2rem minmax(0, 1fr);
  gap: 0.85rem;
  border: 1px dashed var(--line);
  padding: 0.9rem;
  background: #0b243c;
}
.quote__who {
  font-family: var(--mono);
  font-size: 0.8rem;
  color: var(--accent);
}
.quote__who span { display: block; color: var(--muted); margin-top: 0.25rem; font-family: var(--sans); }
.plats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.7rem;
}
.plat {
  border: 1px solid var(--line-dim);
  padding: 0.85rem 0.8rem 1rem;
  background: #0b243c;
}
.plat strong {
  display: block;
  font-family: var(--mono);
  color: var(--ink-strong);
  margin-bottom: 0.35rem;
  letter-spacing: 0.04em;
}
.metrics {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.65rem;
  margin: 0.4rem 0 1rem;
}
.metric {
  border: 1px solid var(--line);
  padding: 0.85rem 0.7rem;
  text-align: center;
  background: #0b243c;
}
.metric b {
  display: block;
  font-family: var(--mono);
  color: var(--accent);
  font-size: 1.15rem;
  margin-bottom: 0.3rem;
}
.metric span { color: var(--muted); font-size: 0.88rem; }
.grid {
  width: 100%;
  border-collapse: collapse;
  margin: 0.4rem 0 1rem;
  font-size: 0.95rem;
}
.grid th,
.grid td {
  border: 1px solid var(--line-dim);
  padding: 0.5rem 0.65rem;
  text-align: left;
  vertical-align: top;
}
.grid th {
  background: #071624;
  color: var(--line);
  font-family: var(--mono);
  font-weight: 400;
  font-size: 0.82rem;
  letter-spacing: 0.04em;
}
.steps { margin: 0 0 1rem; padding-left: 1.35rem; }
.steps li { margin-bottom: 0.55rem; }
.revs { display: grid; gap: 0.65rem; margin-bottom: 0.8rem; }
.rev {
  border-left: 3px solid var(--accent);
  padding: 0.55rem 0.8rem;
  background: #0b243c;
}
.rev time {
  display: block;
  font-family: var(--mono);
  color: var(--accent);
  font-size: 0.8rem;
  margin-bottom: 0.2rem;
}

.faq + .faq { border-top: 1px solid var(--line-dim); }
.faq { padding: 0.85rem 0; }
.faq h3 { color: var(--ink-strong); }

/* 页脚 */
.site-foot {
  background: var(--head);
  border-top: 2px solid var(--line);
  padding: 1.35rem 0 2rem;
  color: var(--muted);
  font-size: 0.92rem;
}
.foot-nav { margin-bottom: 0.7rem; }
.foot-nav a { margin-right: 1rem; }
.safe { color: var(--safe); font-weight: 700; }

@media (max-width: 900px) {
  .hero-grid,
  .cols,
  .plats,
  .metrics,
  .quote { grid-template-columns: 1fr; }
  .nav-toggle { display: inline-flex; }
  .nav {
    display: none;
    flex-direction: column;
    width: 100%;
  }
  .nav.is-open { display: flex; }
  .sheet-head__bar { flex-wrap: wrap; padding: 0.55rem 0; }
  .stamp { align-self: stretch; }
}