@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Mono:wght@400;500;600&family=Source+Serif+4:opsz,wght@8..60,400;8..60,600&display=swap');

:root {
  color-scheme: dark;
  --bg: #08090b;
  --bg-raised: #0f1114;
  --line: #23262b;
  --line-bright: #3a3f47;
  --ink: #e7e5df;
  --ink-dim: #8b8f97;
  --amber: #ffb454;
  --amber-dim: #8a6a3d;
  --phosphor: #5eff8f;
  --serif: 'Source Serif 4', Georgia, serif;
  --mono: 'IBM Plex Mono', ui-monospace, 'SF Mono', Menlo, monospace;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background:
    repeating-linear-gradient(180deg, rgba(255, 255, 255, 0.012) 0px, rgba(255, 255, 255, 0.012) 1px, transparent 1px, transparent 3px),
    radial-gradient(ellipse 900px 500px at 15% -10%, rgba(255, 180, 84, 0.08), transparent 60%),
    var(--bg);
  color: var(--ink);
  font-family: var(--serif);
  font-size: 17px;
  line-height: 1.7;
  min-height: 100vh;
}

::selection {
  background: var(--amber);
  color: #1a1300;
}

a {
  color: var(--amber);
  text-decoration-color: var(--amber-dim);
  text-underline-offset: 3px;
}

a:hover {
  text-decoration-color: var(--amber);
}

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

.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 28px;
  border-bottom: 1px solid var(--line);
  background: rgba(8, 9, 11, 0.85);
  backdrop-filter: blur(10px);
  font-family: var(--mono);
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--ink);
  text-decoration: none;
  font-weight: 600;
  letter-spacing: 0.14em;
  font-size: 13px;
}

.brand .eye {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  border: 1.5px solid var(--amber);
  display: grid;
  place-items: center;
  position: relative;
}

.brand .eye::after {
  content: '';
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--amber);
  box-shadow: 0 0 8px var(--amber);
  animation: blink 5s infinite;
}

@keyframes blink {
  0%, 92%, 100% { transform: scaleY(1); }
  95% { transform: scaleY(0.1); }
}

.topbar nav {
  display: flex;
  gap: 22px;
}

.topbar nav a {
  color: var(--ink-dim);
  text-decoration: none;
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding-bottom: 3px;
  border-bottom: 1px solid transparent;
}

.topbar nav a:hover,
.topbar nav a.active {
  color: var(--amber);
  border-bottom-color: var(--amber);
}

/* ---------- layout ---------- */

.shell {
  max-width: 1080px;
  margin: 0 auto;
  padding: 56px 28px 100px;
  display: grid;
  grid-template-columns: 200px minmax(0, 1fr);
  gap: 56px;
}

@media (max-width: 780px) {
  .shell {
    grid-template-columns: 1fr;
  }
  aside.toc {
    display: none;
  }
}

/* ---------- table of contents ---------- */

aside.toc {
  position: sticky;
  top: 90px;
  align-self: start;
  font-family: var(--mono);
  font-size: 12px;
}

aside.toc .label {
  color: var(--ink-dim);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  font-size: 10px;
  margin-bottom: 14px;
}

aside.toc ol {
  list-style: none;
  margin: 0;
  padding: 0;
  border-left: 1px solid var(--line);
}

aside.toc li a {
  display: block;
  padding: 7px 0 7px 16px;
  margin-left: -1px;
  border-left: 1px solid transparent;
  color: var(--ink-dim);
  text-decoration: none;
  line-height: 1.4;
}

aside.toc li a:hover {
  color: var(--ink);
  border-left-color: var(--line-bright);
}

aside.toc li a.active {
  color: var(--amber);
  border-left-color: var(--amber);
}

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

.doc-head {
  margin-bottom: 48px;
}

.doc-head .kicker {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--phosphor);
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 14px;
}

.doc-head .kicker::before {
  content: '';
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--phosphor);
  box-shadow: 0 0 6px var(--phosphor);
}

.doc-head h1 {
  font-family: var(--serif);
  font-size: 44px;
  font-weight: 600;
  margin: 0 0 10px;
  letter-spacing: -0.01em;
}

.stamp {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--ink-dim);
  border-top: 1px dashed var(--line-bright);
  padding-top: 10px;
  margin-top: 18px;
  display: inline-block;
}

.stamp .cursor {
  display: inline-block;
  width: 7px;
  height: 12px;
  background: var(--amber);
  margin-left: 2px;
  vertical-align: -2px;
  animation: cursor 1.1s steps(1) infinite;
}

@keyframes cursor {
  50% { opacity: 0; }
}

/* ---------- sections ---------- */

section {
  margin-bottom: 44px;
  scroll-margin-top: 90px;
}

section h2 {
  font-family: var(--mono);
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--ink);
  display: flex;
  align-items: baseline;
  gap: 12px;
  margin: 0 0 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line);
}

section h2 .num {
  color: var(--amber);
  font-weight: 600;
}

section p, section li {
  color: var(--ink);
  font-size: 16.5px;
}

section p + p {
  margin-top: 14px;
}

section ul {
  padding-left: 22px;
  margin: 14px 0;
}

section li + li {
  margin-top: 8px;
}

section li::marker {
  color: var(--amber-dim);
}

/* ---------- landing (index) ---------- */

.hero {
  padding: 90px 0 40px;
}

.hero .kicker {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--phosphor);
  margin-bottom: 20px;
}

.hero h1 {
  font-family: var(--serif);
  font-size: 64px;
  line-height: 1.05;
  margin: 0 0 18px;
  max-width: 14ch;
}

.hero p {
  color: var(--ink-dim);
  font-size: 18px;
  max-width: 46ch;
  margin: 0 0 40px;
}

.doc-links {
  display: grid;
  gap: 12px;
  max-width: 480px;
}

.doc-links a {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 22px;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: var(--bg-raised);
  text-decoration: none;
  color: var(--ink);
  font-family: var(--mono);
  font-size: 14px;
  letter-spacing: 0.02em;
  transition: border-color 0.15s ease, transform 0.15s ease;
}

.doc-links a:hover {
  border-color: var(--amber-dim);
  transform: translateX(4px);
}

.doc-links a .arrow {
  color: var(--amber);
}

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

footer.sitefoot {
  margin-top: 80px;
  padding-top: 20px;
  border-top: 1px solid var(--line);
  font-family: var(--mono);
  font-size: 11px;
  color: var(--ink-dim);
  letter-spacing: 0.04em;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
}

footer.sitefoot .status {
  color: var(--phosphor);
}