/* HouyiDB site — 深色技术风 / 锈橙强调 / 编辑式排版
   EN: dark technical theme, rust accent, editorial typography. */

:root {
  --bg: #0c0b0a;
  --surface: #12100e;
  --surface-2: #171411;
  --ink: #f1eadf;
  --ink-2: #b8afa1;
  --ink-3: #8a8173;
  --line: #292520;
  --line-2: #3b352c;
  --accent: #dd2626;
  --accent-2: #ff5c5c;
  --accent-ink: #ff9d9d;
  --accent-dim: #7a1414;
  --serif: "Iowan Old Style", "Palatino Linotype", Palatino, "Book Antiqua",
    "Songti SC", "STSong", "Noto Serif CJK SC", "Source Han Serif SC", Georgia, serif;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
  --mono: ui-monospace, "SFMono-Regular", "Cascadia Mono", Menlo, Consolas,
    "Liberation Mono", monospace;
  --wrap: 1200px;
  --gutter: clamp(1.25rem, 4vw, 3.25rem);
  --section: clamp(4.25rem, 9vw, 8rem);
  color-scheme: dark;
}

*,
*::before,
*::after { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

::selection { background: var(--accent); color: #170d07; }

a { color: inherit; }

:focus-visible {
  outline: 2px solid var(--accent-2);
  outline-offset: 3px;
}

h1, h2, h3, p, dl, dd, figure { margin: 0; }

.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: fixed;
  top: 0.75rem;
  left: 0.75rem;
  z-index: 100;
  padding: 0.6rem 0.9rem;
  background: var(--accent);
  color: #170d07;
  font-family: var(--mono);
  font-size: 0.75rem;
  text-decoration: none;
  transform: translateY(-200%);
}
.skip-link:focus { transform: translateY(0); }

/* ---------- Header ---------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(12, 11, 10, 0.88);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.header-inner {
  min-height: 76px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--ink);
  text-decoration: none;
  flex: 0 0 auto;
}

.brand-logo {
  display: block;
  width: auto;
  height: 38px;
  background: #fff;
  padding: 4px 7px;
  border-radius: 3px;
}
.brand-mark {
  width: 30px;
  height: 30px;
  color: var(--ink);
  flex: 0 0 auto;
}
.brand-mark .mark-accent { stroke: var(--accent); }
.brand-mark .mark-dot { fill: var(--accent); }

.brand-text { display: grid; gap: 0.28rem; }
.brand-text strong {
  font-family: var(--serif);
  font-size: 1.22rem;
  font-weight: 500;
  letter-spacing: 0.01em;
  line-height: 1;
}
.brand-text span {
  font-family: var(--mono);
  font-size: 0.58rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-3);
}

.header-right {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  min-width: 0;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: clamp(1rem, 2.2vw, 2rem);
}

.site-nav a {
  display: inline-flex;
  gap: 0.4rem;
  padding: 0.45rem 0;
  border-bottom: 1px solid transparent;
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-2);
  text-decoration: none;
  transition: color 160ms ease, border-color 160ms ease;
}
.site-nav a .nav-no { color: var(--ink-3); }
.site-nav a:hover { color: var(--accent-ink); }
.site-nav a[aria-current="page"] {
  color: var(--ink);
  border-bottom-color: var(--accent);
}

.header-tools {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding-left: 1.25rem;
  border-left: 1px solid var(--line);
}

.lang-switch {
  display: inline-flex;
  border: 1px solid var(--line-2);
  font-family: var(--mono);
  font-size: 0.66rem;
  line-height: 1;
}
.lang-switch span,
.lang-switch a {
  padding: 0.38rem 0.5rem;
  color: var(--ink-3);
  text-decoration: none;
}
.lang-switch a:hover { color: var(--accent-ink); }
.lang-switch [aria-current="true"] { background: var(--ink); color: var(--bg); }

.gh-link {
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.06em;
  color: var(--ink-2);
  text-decoration: none;
  white-space: nowrap;
}
.gh-link:hover { color: var(--accent-ink); }

.nav-toggle {
  display: none;
  padding: 0.5rem 0.7rem;
  border: 1px solid var(--line-2);
  background: transparent;
  color: var(--ink);
  font-family: var(--mono);
  font-size: 0.68rem;
  cursor: pointer;
}
.nav-toggle:hover { border-color: var(--accent); color: var(--accent-ink); }

/* ---------- Typography / shared ---------- */

.kicker {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  font-family: var(--mono);
  font-size: 0.68rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--accent-ink);
}
.kicker::before {
  content: "";
  width: 2.4rem;
  height: 1px;
  background: var(--accent);
  flex: 0 0 auto;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  margin-top: 2rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  min-height: 44px;
  padding: 0.75rem 1.1rem;
  border: 1px solid var(--line-2);
  background: transparent;
  color: var(--ink);
  font-family: var(--mono);
  font-size: 0.74rem;
  letter-spacing: 0.06em;
  text-decoration: none;
  transition: border-color 160ms ease, color 160ms ease, background 160ms ease;
}
.btn:hover { border-color: var(--accent); color: var(--accent-ink); }
.btn--primary {
  background: var(--accent);
  border-color: var(--accent);
  color: #170d07;
  font-weight: 600;
}
.btn--primary:hover { background: var(--accent-2); border-color: var(--accent-2); color: #170d07; }

/* ---------- Hero ---------- */

.hero {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(290px, 0.6fr);
  gap: clamp(2.5rem, 6vw, 5rem);
  align-items: end;
  overflow: hidden;
  padding-block: clamp(3.5rem, 8vw, 7rem) clamp(3rem, 6vw, 5.25rem);
}
.hero::before {
  content: "";
  position: absolute;
  top: -6rem;
  right: -8rem;
  width: min(640px, 70vw);
  height: min(640px, 70vw);
  background-image: radial-gradient(rgba(224, 100, 40, 0.2) 1px, transparent 1px);
  background-size: 22px 22px;
  -webkit-mask-image: radial-gradient(circle at center, #000 0%, transparent 66%);
  mask-image: radial-gradient(circle at center, #000 0%, transparent 66%);
  pointer-events: none;
}

.hero-main { position: relative; z-index: 1; }

.hero h1 {
  margin: 1.2rem 0 1.6rem;
  font-family: var(--serif);
  font-size: clamp(2.7rem, 6.5vw, 5.7rem);
  font-weight: 500;
  line-height: 1.04;
  letter-spacing: -0.015em;
  text-wrap: balance;
}
.hero h1 .accent { display: block; color: var(--accent); }
html[lang="en-US"] .hero h1,
html[lang="en"] .hero h1 { letter-spacing: -0.035em; }

.lede {
  max-width: 37em;
  color: var(--ink-2);
  font-size: clamp(1rem, 1.35vw, 1.18rem);
  line-height: 1.9;
}
.lede strong { color: var(--ink); font-weight: 500; }

code {
  padding: 0.08em 0.3em;
  background: rgba(241, 234, 223, 0.055);
  color: var(--ink-2);
  font-family: var(--mono);
  font-size: 0.88em;
}
pre code { padding: 0; background: none; color: inherit; font-size: inherit; }

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.2rem;
  margin-top: 1.6rem;
  font-family: var(--mono);
  font-size: 0.66rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-3);
}
.hero-meta span { display: inline-flex; align-items: center; gap: 0.5rem; }
.hero-meta span:not(:last-child)::after {
  content: "/";
  color: var(--line-2);
}

.hero-aside {
  position: relative;
  z-index: 1;
  display: grid;
  gap: 1.5rem;
  align-content: end;
}

.index-map {
  display: block;
  width: 100%;
  height: auto;
  overflow: visible;
}
.index-map .layer { stroke: var(--line); stroke-dasharray: 2 6; }
.index-map .edge { stroke: var(--line-2); stroke-width: 1; fill: none; }
.index-map .edge--hot { stroke: var(--accent-dim); }
.index-map .node { fill: var(--bg); stroke: var(--ink-3); stroke-width: 1.2; }
.index-map .node--l0 { stroke: var(--ink-2); }
.index-map .node--hot { fill: var(--accent); stroke: var(--accent); }
.index-map .buffer { fill: var(--ink-3); opacity: 0.55; }
.index-map .label {
  fill: var(--ink-3);
  font-family: var(--mono);
  font-size: 6.5px;
  letter-spacing: 0.14em;
}
.index-map .label--accent { fill: var(--accent-ink); }

.spec-sheet {
  border-top: 2px solid var(--accent);
  border-bottom: 1px solid var(--line-2);
  padding-top: 0.85rem;
}
.spec-sheet h2 {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  font-family: var(--mono);
  font-size: 0.62rem;
  font-weight: 400;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-3);
}
.spec-sheet dl {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  margin-top: 0.55rem;
}
.spec-sheet dt,
.spec-sheet dd {
  padding: 0.58rem 0;
  border-top: 1px solid var(--line);
  font-family: var(--mono);
  font-size: 0.68rem;
  line-height: 1.5;
}
.spec-sheet dt {
  color: var(--ink-3);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding-right: 1rem;
}
.spec-sheet dd {
  color: var(--ink);
  text-align: right;
  overflow-wrap: anywhere;
}

/* ---------- Stats ---------- */

.stat-band {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: var(--surface);
}
.stat-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
}
.stat {
  display: block;
  padding: 1.7rem clamp(1rem, 2vw, 1.6rem) 1.5rem;
  border-left: 1px solid var(--line);
  color: var(--ink);
  text-decoration: none;
  transition: background 160ms ease;
}
.stat:first-child { border-left: 0; padding-left: 0; }
.stat:hover { background: var(--surface-2); }
.stat-value {
  display: block;
  font-family: var(--serif);
  font-size: clamp(1.9rem, 3.6vw, 3rem);
  font-weight: 500;
  line-height: 1;
  letter-spacing: -0.02em;
  font-variant-numeric: tabular-nums;
}
.stat-value small {
  margin-left: 0.3rem;
  font-family: var(--mono);
  font-size: 0.38em;
  letter-spacing: 0.04em;
  color: var(--ink-3);
}
.stat:hover .stat-value { color: var(--accent-ink); }
.stat-label {
  display: block;
  margin-top: 0.7rem;
  font-family: var(--mono);
  font-size: 0.61rem;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  line-height: 1.7;
  color: var(--ink-3);
}
.stat-foot {
  padding: 0 0 1.1rem;
  font-family: var(--mono);
  font-size: 0.62rem;
  letter-spacing: 0.04em;
  color: var(--ink-3);
}
.stat-foot a { color: var(--accent-ink); text-underline-offset: 3px; }

/* ---------- Sections ---------- */

.section {
  padding-block: var(--section);
  border-top: 1px solid var(--line);
}
.section--surface { background: var(--surface); }

.section-head {
  display: grid;
  grid-template-columns: minmax(180px, 0.7fr) minmax(0, 1.6fr);
  gap: clamp(2rem, 6vw, 6rem);
  align-items: start;
  margin-bottom: clamp(2.5rem, 5vw, 4.5rem);
}
.section-head h2 {
  margin-bottom: 1.1rem;
  font-family: var(--serif);
  font-size: clamp(2rem, 4.2vw, 3.5rem);
  font-weight: 500;
  line-height: 1.1;
  letter-spacing: -0.015em;
  text-wrap: balance;
}
.section-intro {
  max-width: 40em;
  color: var(--ink-2);
  font-size: 0.98rem;
  line-height: 1.95;
}

/* ---------- Tenets ---------- */

.tenets { border-top: 1px solid var(--line-2); }
.tenet {
  display: grid;
  grid-template-columns: 4.5rem minmax(0, 1.5fr) minmax(230px, 0.7fr);
  gap: clamp(1.5rem, 4vw, 4rem);
  padding: clamp(2rem, 4vw, 3.2rem) 0;
  border-bottom: 1px solid var(--line);
}
.tenet-no {
  font-family: var(--serif);
  font-size: clamp(2.3rem, 4vw, 3.6rem);
  line-height: 1;
  color: var(--accent);
}
.tenet h3 {
  margin-bottom: 0.85rem;
  font-family: var(--serif);
  font-size: clamp(1.45rem, 2.6vw, 2.05rem);
  font-weight: 500;
  line-height: 1.3;
}
.tenet-body p {
  max-width: 36em;
  color: var(--ink-2);
  font-size: 0.95rem;
  line-height: 1.95;
}
.tenet-specs {
  align-self: center;
  margin: 0;
  padding: 0 0 0 1.4rem;
  border-left: 1px solid var(--line-2);
  list-style: none;
}
.tenet-specs li {
  padding: 0.55rem 0;
  border-top: 1px solid var(--line);
  font-family: var(--mono);
  font-size: 0.65rem;
  line-height: 1.7;
  color: var(--ink-3);
}
.tenet-specs li:first-child { padding-top: 0; border-top: 0; }
.tenet-specs strong {
  display: block;
  margin-bottom: 0.2rem;
  font-weight: 500;
  color: var(--ink-2);
  letter-spacing: 0.05em;
}

/* ---------- Quick start / terminal ---------- */

.quickstart-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(230px, 0.32fr);
  gap: clamp(2rem, 4vw, 3.5rem);
  align-items: start;
}

.terminal {
  position: relative;
  min-width: 0;
  max-width: 100%;
  border: 1px solid var(--line-2);
  background: #080706;
}
.terminal pre { max-width: 100%; }
.quickstart-grid > * { min-width: 0; }
.measure-body,
.measure-layout > *,
.doc-layout > * { min-width: 0; }
.terminal-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  min-height: 40px;
  padding: 0.55rem 0.9rem;
  border-bottom: 1px solid var(--line);
  font-family: var(--mono);
  font-size: 0.6rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-3);
}
.terminal-bar .terminal-hint { margin-left: auto; color: var(--accent-ink); }
.terminal pre {
  margin: 0;
  padding: 1.2rem 1.1rem 1.35rem;
  overflow-x: auto;
  font-family: var(--mono);
  font-size: 0.76rem;
  line-height: 1.8;
  color: #d6ccbd;
  tab-size: 2;
}
.terminal code { white-space: pre; }
.copy-btn {
  padding: 0.28rem 0.5rem;
  border: 1px solid var(--line-2);
  background: transparent;
  color: var(--ink-3);
  font-family: var(--mono);
  font-size: 0.6rem;
  letter-spacing: 0.08em;
  cursor: pointer;
}
.copy-btn:hover,
.copy-btn.is-copied { border-color: var(--accent); color: var(--accent-ink); }

.quick-notes {
  border-top: 2px solid var(--accent);
  padding-top: 1rem;
}
.quick-notes h3 {
  margin-bottom: 1rem;
  font-family: var(--mono);
  font-size: 0.64rem;
  font-weight: 400;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--ink-3);
}
.quick-notes ul {
  margin: 0;
  padding: 0;
  list-style: none;
}
.quick-notes li {
  padding: 0.7rem 0;
  border-top: 1px solid var(--line);
  font-size: 0.82rem;
  line-height: 1.7;
  color: var(--ink-2);
}
.quick-notes li span {
  display: block;
  margin-bottom: 0.2rem;
  font-family: var(--mono);
  font-size: 0.6rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-3);
}
.quick-notes a { color: var(--accent-ink); text-underline-offset: 3px; }

/* ---------- Tables / matrix ---------- */

.table-scroll {
  overflow-x: auto;
  border-top: 1px solid var(--line-2);
}
.table-scroll:focus-visible { outline-offset: -2px; }

.matrix {
  width: 100%;
  min-width: 700px;
  border-collapse: collapse;
  font-size: 0.88rem;
}
.matrix th,
.matrix td {
  padding: 0.9rem 1.1rem;
  border-bottom: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
}
.matrix thead th {
  padding-block: 0.7rem;
  font-family: var(--mono);
  font-size: 0.6rem;
  font-weight: 400;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-3);
  border-bottom-color: var(--line-2);
  white-space: nowrap;
}
.matrix tbody th {
  width: 26%;
  font-weight: 500;
  color: var(--ink);
}
.matrix td { color: var(--ink-2); line-height: 1.7; }
.matrix tbody tr:hover td,
.matrix tbody tr:hover th { background: var(--surface-2); }
.matrix .row-group th {
  padding-top: 1.6rem;
  border-bottom: 0;
  background: transparent;
  color: var(--accent-ink);
  font-family: var(--mono);
  font-size: 0.62rem;
  font-weight: 400;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}
.matrix .row-group:hover th { background: transparent; }
.matrix-foot {
  margin-top: 1rem;
  max-width: 74em;
  font-family: var(--mono);
  font-size: 0.62rem;
  line-height: 1.9;
  color: var(--ink-3);
}

.chip {
  display: inline-block;
  padding: 0.18rem 0.44rem;
  border: 1px solid var(--line-2);
  font-family: var(--mono);
  font-size: 0.56rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-3);
  white-space: nowrap;
}
.chip--beta {
  border-color: var(--accent-dim);
  background: rgba(224, 100, 40, 0.07);
  color: var(--accent-ink);
}
.chip--preview { border-style: dashed; color: var(--ink-2); }
.chip--soon { color: var(--ink-3); }

/* ---------- SDK ---------- */

.sdk-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  border-top: 1px solid var(--line-2);
  border-left: 1px solid var(--line);
}
.sdk-item {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  min-height: 148px;
  padding: 1.35rem;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  color: var(--ink);
  text-decoration: none;
  transition: background 160ms ease;
}
.sdk-item:hover { background: var(--surface-2); }
.sdk-item .lang {
  font-family: var(--serif);
  font-size: 1.35rem;
  font-weight: 500;
  line-height: 1.2;
}
.sdk-item .note {
  color: var(--ink-3);
  font-size: 0.78rem;
  line-height: 1.7;
}
.sdk-item .arrow {
  margin-top: auto;
  font-family: var(--mono);
  font-size: 0.62rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent-ink);
}
.sdk-foot {
  margin-top: 1rem;
  font-family: var(--mono);
  font-size: 0.62rem;
  line-height: 1.9;
  color: var(--ink-3);
}