@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=Space+Grotesk:wght@400;500;600;700&family=JetBrains+Mono:wght@400;500&display=swap');

:root {
  --bg: #f5efe6;
  --paper: #fffaf3;
  --ink: #1d2a30;
  --muted: #66757d;
  --accent: #b65c34;
  --accent-light: #c96a40;
  --line: #20323a;
  --success: #2d7a4f;
  --warning: #b86e00;
  --danger: #c2553b;
  --info: #2563ab;
  --violet: #6b4c9a;
  --shadow: 0 20px 60px rgba(29, 42, 48, 0.10);
  --radius: 22px;
  --page-width: 1460px;
  --prose-width: 980px;
  --toc-width: 280px;
}

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

body {
  margin: 0;
  color: var(--ink);
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", "Inter", system-ui, sans-serif;
  background:
    radial-gradient(circle at 8% 0%, rgba(182, 92, 52, 0.12), transparent 24%),
    radial-gradient(circle at 100% 18%, rgba(76, 125, 178, 0.10), transparent 24%),
    linear-gradient(180deg, #fbf6ee 0%, var(--bg) 100%);
  background-attachment: fixed;
  line-height: 1.72;
  padding-top: 64px;
}

::selection { background: rgba(182, 92, 52, 0.22); color: var(--ink); }
*:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
a { color: inherit; text-decoration: none; }

/* ── Navigation ── */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  background: rgba(29, 42, 48, 0.95);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.nav-container {
  max-width: 1680px; margin: 0 auto; height: 64px; padding: 0 26px;
  display: flex; align-items: center; justify-content: space-between; gap: 20px;
}

.nav-brand {
  display: flex; align-items: center; gap: 12px;
  text-decoration: none; color: white;
}
.nav-brand img {
  width: 32px; height: 32px; border-radius: 8px;
}
.nav-brand span {
  font-weight: 600; font-size: 16px;
}

.nav-categories {
  display: flex; align-items: center; gap: 4px;
  margin-left: 32px; padding-left: 32px;
  border-left: 1px solid rgba(255, 255, 255, 0.1);
}

.nav-dropdown {
  position: relative;
}

.nav-category {
  padding: 6px 14px; border-radius: 8px;
  text-decoration: none; color: rgba(255, 255, 255, 0.6);
  font-size: 13px; font-weight: 500;
  transition: all 0.2s ease;
  display: inline-block;
}
.nav-category:hover {
  color: white; background: rgba(255, 255, 255, 0.1);
}
.nav-category.active {
  color: #b65c34; background: rgba(182, 92, 52, 0.15);
}

.nav-dropdown-menu {
  display: none;
  position: absolute;
  top: calc(100% - 4px);
  left: 0;
  padding: 12px 8px 8px;
  min-width: 200px;
  background: rgba(29, 42, 48, 0.97);
  backdrop-filter: blur(20px);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 12px;
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.3);
  z-index: 1001;
}

.nav-dropdown:hover .nav-dropdown-menu {
  display: block;
}

.nav-dropdown-menu a {
  display: block;
  padding: 8px 14px;
  border-radius: 8px;
  color: rgba(255, 255, 255, 0.6);
  font-size: 13px;
  font-weight: 400;
  text-decoration: none;
  transition: all 0.15s ease;
  white-space: nowrap;
}

.nav-dropdown-menu a:hover {
  color: white;
  background: rgba(255, 255, 255, 0.1);
}

.nav-dropdown-menu a.active {
  color: #b65c34;
  background: rgba(182, 92, 52, 0.15);
}

.nav-cta {
  padding: 8px 16px; background: var(--accent);
  color: white; border-radius: 8px;
  text-decoration: none; font-size: 14px; font-weight: 500;
  transition: all 0.2s ease;
}
.nav-cta:hover { background: var(--accent-light); }

.nav-lang {
  padding: 6px 12px;
  border-radius: 8px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  background: transparent;
  color: rgba(255, 255, 255, 0.7);
  font-size: 12px;
  font-weight: 600;
  text-decoration: none;
  transition: all 0.2s ease;
  letter-spacing: 0.02em;
}
.nav-lang:hover {
  color: white;
  border-color: rgba(255, 255, 255, 0.4);
  background: rgba(255, 255, 255, 0.08);
}

/* ── Page Container ── */
.page {
  width: min(var(--page-width), calc(100vw - 28px));
  margin: 18px auto 30px; padding: 26px 26px 30px;
  background: rgba(255, 250, 243, 0.93);
  border: 1px solid rgba(29, 42, 48, 0.10);
  border-radius: 30px;
  box-shadow: var(--shadow);
  backdrop-filter: blur(8px);
}

/* ── Hero ── */
.hero {
  position: relative; overflow: hidden;
  padding: 42px 44px 38px;
  border-radius: 28px;
  background: linear-gradient(180deg, rgba(255,255,255,0.98) 0%, rgba(255,250,243,0.98) 100%);
  border: 1px solid rgba(29, 42, 48, 0.10);
  box-shadow: var(--shadow);
  margin-bottom: 28px;
}
.hero::before {
  content: ""; position: absolute; inset: auto auto -130px -90px;
  width: 280px; height: 280px;
  background: radial-gradient(circle, rgba(182, 92, 52, 0.10), transparent 65%);
  pointer-events: none;
}
.hero::after {
  content: ""; position: absolute; inset: -100px -80px auto auto;
  width: 220px; height: 220px;
  background: radial-gradient(circle, rgba(182, 92, 52, 0.06), transparent 68%);
  pointer-events: none;
}

.eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 8px 13px; border-radius: 999px;
  color: var(--ink); background: rgba(29, 42, 48, 0.04);
  border: 1px solid rgba(29, 42, 48, 0.10); font-size: 13px;
  margin-bottom: 14px;
}

h1 {
  margin: 0 0 14px;
  font-family: "Space Grotesk", "Segoe UI", sans-serif;
  font-size: clamp(36px, 5.2vw, 58px);
  line-height: 1.05;
  letter-spacing: -0.028em;
}

.gradient-text {
  background: linear-gradient(135deg, var(--accent), var(--accent-light));
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text; color: transparent;
}

.subtitle {
  margin: 0;
  max-width: 880px;
  color: var(--muted);
  font-size: 17px;
  line-height: 1.92;
}

/* ── Legend / Tags ── */
.legend {
  display: flex; flex-wrap: wrap; gap: 10px;
  margin-top: 20px;
}

.tag {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 8px 13px; border-radius: 999px;
  border: 1px solid rgba(29, 42, 48, 0.12);
  background: #fff;
  color: var(--muted); font-size: 13px;
}

.dot { width: 10px; height: 10px; border-radius: 50%; }
.dot.brain { background: var(--success); box-shadow: 0 0 8px rgba(45,122,79,0.35); }
.dot.protocol { background: var(--warning); box-shadow: 0 0 8px rgba(184,110,0,0.35); }
.dot.safe { background: var(--danger); box-shadow: 0 0 8px rgba(194,85,59,0.35); }
.dot.hal { background: var(--info); box-shadow: 0 0 8px rgba(37,99,171,0.35); }
.dot.return { background: var(--violet); box-shadow: 0 0 8px rgba(107,76,154,0.35); }

/* ── Layout with TOC ── */
.layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) var(--toc-width);
  gap: 30px;
  align-items: start;
}

.content { min-width: 0; max-width: var(--prose-width); }

.toc {
  position: sticky; top: 92px;
  padding: 20px;
  border-radius: 24px;
  background: rgba(255, 255, 255, 0.95);
  border: 1px solid rgba(29, 42, 48, 0.10);
  box-shadow: var(--shadow);
  backdrop-filter: blur(16px);
}

.toc-title {
  margin: 0 0 14px;
  font-family: "Space Grotesk", "Segoe UI", sans-serif;
  font-size: 15px; color: var(--ink);
}

.toc a {
  display: block;
  padding: 10px 13px; margin-bottom: 6px; border-radius: 12px;
  color: var(--muted); font-size: 14px;
  line-height: 1.45; transition: all .2s ease;
  text-decoration: none;
}
.toc a:hover, .toc a.active {
  color: var(--ink); background: rgba(182, 92, 52, 0.10);
  box-shadow: 0 0 0 1px rgba(182, 92, 52, 0.16) inset;
}

/* ── Cards ── */
.card, .mini-card {
  background: linear-gradient(180deg, rgba(255,255,255,0.98), rgba(255,250,243,0.98));
  border: 1px solid rgba(29, 42, 48, 0.10);
  border-radius: 24px;
  box-shadow: var(--shadow);
}

.card-hover {
  transition: transform .35s cubic-bezier(.16,1,.3,1), box-shadow .35s ease, border-color .35s ease;
}
.card-hover:hover {
  transform: translateY(-5px);
  box-shadow: 0 18px 40px rgba(29, 42, 48, 0.10);
  border-color: rgba(182, 92, 52, 0.25);
}

.card {
  padding: 26px;
  margin-bottom: 24px;
  scroll-margin-top: 92px;
}

.card h2, .mini-card h3, .mini-card h4 {
  margin: 0 0 12px;
  color: var(--ink);
  font-family: "Space Grotesk", "Segoe UI", sans-serif;
}

.card h2 {
  font-size: 25px;
  line-height: 1.28;
  letter-spacing: -0.01em;
}

.card p, .card li, .mini-card p, .mini-card li {
  color: var(--muted); font-size: 15px; line-height: 1.86;
}

.lead {
  margin-top: 0; margin-bottom: 16px;
  color: var(--muted); font-size: 16px; line-height: 1.88;
}

/* ── Grids ── */
.grid-2, .grid-3, .grid-4 {
  display: grid; gap: 16px; margin-top: 16px;
}
.grid-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }

.mini-card { padding: 22px; }

/* ── Callout ── */
.callout {
  margin: 16px 0; padding: 16px 18px;
  border-radius: 18px;
  background: rgba(182, 92, 52, 0.04);
  border: 1px solid rgba(182, 92, 52, 0.12);
  border-left: 4px solid var(--accent);
  color: var(--muted);
  font-size: 15px; line-height: 1.86;
}
.callout strong { color: var(--ink); }

/* ── Tables ── */
table {
  width: 100%; border-collapse: collapse; margin-top: 16px;
  overflow: hidden; border-radius: 18px;
  background: rgba(255, 255, 255, 0.5);
  border: 1px solid rgba(29, 42, 48, 0.10);
}

th, td {
  text-align: left;
  padding: 13px 15px;
  border-bottom: 1px solid rgba(29, 42, 48, 0.08);
  vertical-align: top; font-size: 14.5px; line-height: 1.72;
}

th {
  background: rgba(29, 42, 48, 0.04);
  color: var(--ink); font-weight: 700;
}

td { color: var(--muted); }
tr:last-child td { border-bottom: none; }
tr:hover td { background: rgba(29, 42, 48, 0.02); }

/* ── Code ── */
pre {
  margin: 16px 0 0; padding: 18px;
  border-radius: 18px;
  background: #f4f0e8;
  border: 1px solid rgba(29, 42, 48, 0.10);
  color: var(--ink);
  font-family: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  font-size: 13.5px;
  line-height: 1.68;
  overflow-x: auto;
}

code {
  font-family: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  font-size: 0.92em;
  background: rgba(29, 42, 48, 0.06);
  padding: 2px 6px; border-radius: 6px;
  color: var(--accent);
}

pre code { background: none; padding: 0; color: inherit; }

.cmd-block {
  margin: 12px 0 0; padding: 14px 16px;
  border-radius: 14px;
  background: #1d2a30;
  color: #f5f5f5;
  font-family: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  font-size: 13.5px;
  white-space: pre-wrap;
  overflow-wrap: anywhere;
  overflow-x: auto;
}
.cmd-block code { background: none; padding: 0; color: inherit; }

/* ── Timeline ── */
.timeline {
  position: relative;
  margin-top: 18px;
  padding-left: 28px;
}
.timeline::before {
  content: "";
  position: absolute;
  left: 8px; top: 6px; bottom: 6px;
  width: 2px;
  background: linear-gradient(180deg, var(--accent), rgba(182,92,52,0.2));
  border-radius: 2px;
}
.timeline-item {
  position: relative;
  margin-bottom: 18px;
}
.timeline-item::before {
  content: "";
  position: absolute;
  left: -24px; top: 6px;
  width: 10px; height: 10px;
  border-radius: 50%;
  background: var(--paper);
  border: 2px solid var(--accent);
  box-shadow: 0 0 0 3px rgba(182,92,52,0.08);
}
.timeline-content {
  background: rgba(255,255,255,0.5);
  border: 1px solid rgba(29, 42, 48, 0.08);
  border-radius: 16px;
  padding: 14px 16px;
}
.timeline-content h4 { margin: 0 0 6px; font-size: 15px; color: var(--ink); }
.timeline-content p { margin: 0; font-size: 14px; color: var(--muted); }

/* ── Progress ── */
.progress-wrap {
  margin-top: 10px;
}
.progress-bar {
  background: rgba(29, 42, 48, 0.06);
  border-radius: 999px;
  height: 10px;
  overflow: hidden;
}
.progress-bar > div {
  height: 100%;
  border-radius: 999px;
  background: linear-gradient(90deg, var(--success), #4caf7c);
}
.progress-label {
  display: flex; justify-content: space-between;
  font-size: 12px; color: var(--muted); margin-bottom: 6px;
}

/* ── Flow Track ── */
.flow-track {
  display: flex; align-items: center; gap: 10px; flex-wrap: wrap;
  margin: 14px 0; padding: 18px;
  background: linear-gradient(90deg, rgba(182,92,52,0.08), transparent);
  border-radius: 16px; border-left: 3px solid var(--accent);
}
.flow-step {
  padding: 10px 16px; border-radius: 999px;
  background: rgba(255,255,255,0.6); border: 1px solid rgba(29, 42, 48, 0.10);
  font-size: 13px;
}
.flow-arrow { color: var(--muted); }

/* ── Layer Card ── */
.layer-card { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; margin-top: 16px; }

/* ── Signal Card ── */
.signal-card {
  padding: 16px; border-radius: 14px;
  background: rgba(255,255,255,0.5);
  border: 1px solid rgba(29, 42, 48, 0.08);
}

/* ── Check Card ── */
.check-card {
  display: flex; align-items: flex-start; gap: 14px;
  padding: 18px; border-radius: 16px;
  background: rgba(255,255,255,0.5);
  border: 1px solid rgba(29, 42, 48, 0.08);
}
.check-icon {
  width: 36px; height: 36px; border-radius: 10px;
  display: grid; place-items: center;
  font-size: 18px; background: rgba(182,92,52,0.12); flex-shrink: 0;
}

/* ── HW Card ── */
.hw-card {
  padding: 18px; border-radius: 18px;
  background: rgba(255,255,255,0.5);
  border: 1px solid rgba(29, 42, 48, 0.08);
}
.hw-header {
  display: flex; align-items: center; justify-content: space-between;
  margin-bottom: 10px;
}

/* ── Install Card ── */
.install-card {
  padding: 18px; border-radius: 16px;
  background: rgba(255,255,255,0.5);
  border: 1px solid rgba(29, 42, 48, 0.08);
}

/* ── Tree ── */
.tree {
  font-family: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--muted);
  background: rgba(255,255,255,0.5);
  border: 1px solid rgba(29, 42, 48, 0.08);
  border-radius: 16px;
  padding: 16px 18px;
}

/* ── Status Pill ── */
.status-pill {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 4px 10px; border-radius: 999px;
  font-size: 12px; font-weight: 500;
}
.status-pill.done { background: rgba(95,158,119,0.15); color: #7ddba8; }
.status-pill.wip { background: rgba(204,149,30,0.15); color: #f0c674; }
.status-pill.todo { background: rgba(136,136,136,0.15); color: #aaa; }

/* ── Issue Badge ── */
.issue-badge {
  display: inline-block; padding: 3px 8px; border-radius: 6px;
  font-size: 12px; font-weight: 600; margin-right: 6px;
}

/* ── Phase Card ── */
.phase-card { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; margin: 16px 0; }

/* ── Step Number ── */
.step-num {
  width: 28px; height: 28px; border-radius: 50%;
  display: grid; place-items: center;
  font-size: 13px; font-weight: 700;
  background: var(--accent); color: white;
}

/* ── File Node ── */
.file-node {
  padding: 14px 16px; border-radius: 14px;
  background: rgba(255,255,255,0.5);
  border: 1px solid rgba(29, 42, 48, 0.08);
  font-size: 13px;
}
.file-node strong { display: block; margin-bottom: 4px; color: var(--ink); }

/* ── Check Item ── */
.check-item {
  display: flex; align-items: flex-start; gap: 12px;
  padding: 14px; border-radius: 14px;
  background: rgba(255,255,255,0.5);
  border: 1px solid rgba(29, 42, 48, 0.08);
  margin-bottom: 10px;
}
.check-box {
  width: 20px; height: 20px; border-radius: 6px;
  border: 2px solid rgba(29, 42, 48, 0.15);
  flex-shrink: 0; margin-top: 2px;
}

/* ── Interface Grid ── */
.iface-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px; }

/* ── Rule Grid ── */
.rule-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px; }

/* ── Arch Diagram ── */
.arch-diagram {
  background: rgba(255,255,255,0.5);
  border: 1px solid rgba(29, 42, 48, 0.10);
  border-radius: 20px; padding: 22px; margin: 18px 0;
}

/* ── Mermaid ── */
.mermaid {
  min-height: 180px;
  overflow: visible !important;
  display: flex;
  justify-content: center;
  align-items: center;
}
.mermaid svg {
  max-width: 100%;
  height: auto;
}

/* ── Footer ── */
.footer {
  margin-top: 24px; padding: 18px;
  border-radius: 18px;
  background: rgba(182, 92, 52, 0.04);
  border: 1px solid rgba(182, 92, 52, 0.10);
  color: var(--muted);
  font-size: 14px;
  line-height: 1.7;
}

/* ── Card Grid (for index pages) ── */
.card-grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; }
.card-grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }

/* ── Responsive ── */
@media (max-width: 1100px) {
  .layout { grid-template-columns: 1fr; }
  .toc { display: none; }
}

@media (max-width: 980px) {
  .layer-card, .phase-card { grid-template-columns: 1fr; }
}

@media (max-width: 768px) {
  .nav-categories { display: none; }
  .nav-container { padding: 0 16px; }
  .page { padding: 18px 14px 22px; width: min(100vw - 14px, 1680px); }
  .hero { padding: 28px 24px 24px; }
  h1 { font-size: 34px; }
  .grid-2, .grid-3, .grid-4, .card-grid-2, .card-grid-3 { grid-template-columns: 1fr; }
  .iface-grid, .rule-grid { grid-template-columns: 1fr; }
}