:root {
  --ink:#0A0B10; --ash:#15161D; --char:#1F2029;
  --steel:#9A9AA3; --bone:#E9E5DA; --paper:#F2EFE8;
  --ember:#FF4D1A; --spark:#FF8A3C;
  --rule:rgba(233,229,218,0.14); --rule-strong:rgba(233,229,218,0.32);
}
* { box-sizing: border-box; }
html, body { margin:0; padding:0; }
html {
  background: var(--ink);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  font-feature-settings: "ss01","ss02","cv01","cv11";
}
body {
  background: var(--ink);
  color: var(--bone);
  font-family: "Geist", system-ui, -apple-system, "Segoe UI", sans-serif;
}
::selection { background: var(--ember); color: var(--ink); }

.site-header {
  position: sticky; top: 0; z-index: 10;
  display: flex; align-items: center; justify-content: space-between;
  padding: 16px 28px;
  background: rgba(10,11,16,0.78);
  backdrop-filter: blur(14px) saturate(140%);
  -webkit-backdrop-filter: blur(14px) saturate(140%);
  border-bottom: 1px solid var(--rule);
}
.brand { display:inline-flex; align-items:center; gap:10px; text-decoration:none; color:var(--bone); }
.brand .mark {
  width: 28px; height: 28px;
  background: url("/images/logo-icon.svg") center/contain no-repeat;
  display: inline-block;
  filter: brightness(0) invert(1);
}
.brand .name {
  font-family:"Geist", system-ui, sans-serif;
  font-weight:600; font-size:18px;
  letter-spacing:-0.02em;
  text-transform: uppercase;
}
.brand .tag {
  font-family:"Geist Mono", ui-monospace, monospace;
  font-size:10px; text-transform:uppercase; letter-spacing:0.32em;
  color: var(--steel); margin-left:6px;
}
.topnav a {
  color: var(--bone); text-decoration: none;
  margin-left:24px;
  font-family:"Geist Mono", ui-monospace, monospace;
  font-size:11px; text-transform:uppercase; letter-spacing:0.18em;
  opacity: 0.78;
  transition: color .18s, opacity .18s;
}
.topnav a:hover { color: var(--ember); opacity: 1; }

.layout { display: grid; grid-template-columns: 280px 1fr; max-width: 1400px; margin: 0 auto; min-height: calc(100vh - 60px); }
.sidebar {
  padding: 28px 16px 60px;
  border-right: 1px solid var(--rule);
  position: sticky; top: 60px;
  height: calc(100vh - 60px);
  overflow-y: auto;
  scrollbar-width: thin;
  scrollbar-color: var(--char) var(--ink);
}
.sidebar::-webkit-scrollbar { width: 6px; }
.sidebar::-webkit-scrollbar-track { background: transparent; }
.sidebar::-webkit-scrollbar-thumb { background: var(--char); border-radius: 3px; }

.nav-tab {
  font-family:"Geist Mono", ui-monospace, monospace;
  font-size:10px; text-transform:uppercase; letter-spacing:0.32em;
  color: var(--ember);
  padding: 18px 12px 8px;
}
.nav-group {
  font-family:"Geist Mono", ui-monospace, monospace;
  font-size:9px; text-transform:uppercase; letter-spacing:0.28em;
  color: var(--steel);
  padding: 14px 12px 4px;
}
.nav-link {
  display: block;
  padding: 6px 12px;
  color: rgba(233,229,218,0.78);
  text-decoration: none;
  border-radius: 4px;
  font-size:14px;
  transition: background .15s, color .15s;
}
.nav-link:hover { background: rgba(233,229,218,0.06); color: var(--bone); }
.nav-link.active { background: var(--ember); color: var(--ink); font-weight: 500; }

.content { padding: 56px 56px 96px; max-width: 880px; }
.content h1 {
  font-family:"Geist", system-ui, sans-serif;
  font-weight:600;
  font-size: clamp(2.2rem, 5vw, 4rem);
  line-height:0.92;
  letter-spacing:-0.04em;
  margin: 0 0 16px;
  color: var(--bone);
}
.lede {
  font-family:"Geist", system-ui, sans-serif;
  font-weight:400;
  font-size: clamp(1.05rem, 1.5vw, 1.25rem);
  color: var(--steel);
  margin: 0 0 36px;
  line-height: 1.5;
  max-width: 720px;
}
.prose { font-size: 16px; line-height: 1.7; color: rgba(233,229,218,0.92); }
.prose h2 {
  font-family:"Geist", system-ui, sans-serif;
  font-weight:600;
  font-size: 1.85rem;
  margin: 56px 0 14px;
  letter-spacing:-0.02em;
  color: var(--bone);
}
.prose h3 {
  font-family:"Geist", system-ui, sans-serif;
  font-weight:500;
  font-size: 1.25rem;
  margin: 36px 0 10px;
  letter-spacing:-0.01em;
  color: var(--bone);
}
.prose h4 {
  font-family:"Geist Mono", ui-monospace, monospace;
  font-weight:500;
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.18em;
  margin: 28px 0 8px;
  color: var(--ember);
}
.prose p { margin: 14px 0; }
.prose a {
  color: var(--ember);
  text-decoration: none;
  background-image: linear-gradient(currentColor, currentColor);
  background-size: 100% 1px; background-repeat: no-repeat; background-position: 0 100%;
  transition: background-size .25s, color .25s;
}
.prose a:hover { background-size: 100% 0.18em; color: var(--spark); }
.prose ul, .prose ol { padding-left: 24px; }
.prose li { margin: 6px 0; }
.prose code {
  font-family:"Geist Mono", ui-monospace, monospace;
  font-size: 0.88em;
  background: var(--ash);
  padding: 2px 7px;
  border-radius: 4px;
  border: 1px solid var(--char);
  color: var(--bone);
}
.prose pre {
  background: var(--ash);
  color: var(--bone);
  padding: 20px 22px;
  border-radius: 12px;
  border: 1px solid var(--char);
  overflow-x:auto;
  font-size: 13.5px;
  line-height:1.6;
  font-family:"Geist Mono", ui-monospace, monospace;
}
.prose pre code { background: transparent; padding: 0; border: 0; color: inherit; }
.prose table { border-collapse: collapse; margin: 18px 0; width: 100%; font-size: 14px; }
.prose th, .prose td {
  border: 1px solid var(--rule);
  padding: 10px 14px;
  text-align: left;
}
.prose th {
  background: var(--ash);
  color: var(--ember);
  font-family:"Geist Mono", ui-monospace, monospace;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.18em;
  font-weight: 500;
}
.prose blockquote {
  border-left: 2px solid var(--ember);
  margin: 18px 0;
  padding: 4px 18px;
  color: var(--steel);
}
.prose hr { border: 0; border-top: 1px solid var(--rule); margin: 36px 0; }

.cardgrid { display: grid; gap: 14px; margin: 18px 0 28px; }
.cardgrid.cols-2 { grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }
.cardgrid.cols-3 { grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }
.card {
  display: block;
  padding: 22px 24px;
  border: 1px solid var(--rule-strong);
  border-radius: 14px;
  background: var(--ash);
  text-decoration: none;
  color: var(--bone);
  transition: border-color .2s, transform .2s, background .2s;
}
.card:hover { border-color: var(--ember); transform: translateY(-2px); background: var(--char); }
.card h3 {
  font-family:"Geist", system-ui, sans-serif;
  font-weight:500;
  margin: 0 0 8px;
  letter-spacing:-0.01em;
  color: var(--bone);
}
.card-arrow { color: var(--ember); }
.card p { color: var(--steel); margin: 0; font-size: 14px; }

.page-footer {
  margin-top: 72px;
  padding-top: 24px;
  border-top: 1px solid var(--rule);
}
.hot {
  color: var(--ember);
  font-family:"Geist Mono", ui-monospace, monospace;
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.18em;
  text-decoration: none;
}
.hot:hover { color: var(--spark); }

@media (max-width: 880px) {
  .layout { grid-template-columns: 1fr; }
  .sidebar { position: static; height: auto; border-right: none; border-bottom: 1px solid var(--rule); }
  .content { padding: 32px 24px 64px; }
}