:root {
  --paper: oklch(0.985 0.01 85);
  --ink: oklch(0.22 0.025 265);
  --muted: oklch(0.44 0.02 265);
  --line: oklch(0.9 0.015 80);
  --amber: oklch(0.46 0.13 70);
  --amber-bright: oklch(0.7 0.16 70);
  --indigo: oklch(0.42 0.12 275);
  --sidebar: oklch(0.97 0.012 85);
  --code-bg: oklch(0.95 0.012 85);
  --note-bg: oklch(0.96 0.02 85);
  --focus: oklch(0.46 0.13 70);
  --header-h: 3.5rem;
  --sidebar-w: 16.5rem;
  --font: "Figtree", system-ui, sans-serif;
  --display: "Outfit", system-ui, sans-serif;
  color-scheme: light;
}

html.dark {
  --paper: oklch(0.17 0.012 265);
  --ink: oklch(0.96 0.005 250);
  --muted: oklch(0.74 0.02 255);
  --line: oklch(0.3 0.014 260);
  --amber: oklch(0.82 0.14 75);
  --amber-bright: oklch(0.78 0.16 70);
  --indigo: oklch(0.78 0.1 275);
  --sidebar: oklch(0.2 0.013 265);
  --code-bg: oklch(0.24 0.014 265);
  --note-bg: oklch(0.24 0.02 70);
  --focus: oklch(0.82 0.14 75);
  color-scheme: dark;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font);
  font-size: 1.0625rem;
  line-height: 1.6;
}

a { color: var(--amber); text-underline-offset: 0.15em; }
a:hover { text-decoration-thickness: 2px; }

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

.skip {
  position: absolute;
  left: 1rem;
  top: -4rem;
  z-index: 20;
  background: var(--ink);
  color: var(--paper);
  padding: 0.5rem 0.75rem;
  border-radius: 0.375rem;
}
.skip:focus { top: 0.5rem; }

.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  gap: 1rem;
  height: var(--header-h);
  padding: 0 1rem;
  background: color-mix(in oklch, var(--paper) 92%, transparent);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(10px);
}

.brand {
  display: flex;
  align-items: baseline;
  gap: 0.45rem;
  color: var(--ink);
  text-decoration: none;
  font-family: var(--display);
  font-weight: 650;
  font-size: 1.15rem;
  letter-spacing: -0.02em;
}
.brand span { color: var(--muted); font-weight: 500; font-size: 0.95rem; }

.search {
  position: relative;
  flex: 1;
  max-width: 28rem;
  margin-left: auto;
}

.search input {
  width: 100%;
  height: 2.5rem;
  padding: 0 0.75rem;
  border: 1px solid var(--line);
  border-radius: 0.5rem;
  background: var(--paper);
  color: var(--ink);
  font: inherit;
  font-size: 0.95rem;
}

.search-panel {
  position: absolute;
  top: calc(100% + 0.35rem);
  left: 0;
  right: 0;
  margin: 0;
  padding: 0.35rem;
  list-style: none;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 0.5rem;
  box-shadow: 0 12px 32px oklch(0.2 0.02 265 / 0.12);
}

.search-panel a {
  display: block;
  padding: 0.55rem 0.65rem;
  border-radius: 0.35rem;
  color: var(--ink);
  text-decoration: none;
}
.search-panel a:hover,
.search-panel a[aria-selected="true"] { background: var(--code-bg); }
.search-panel small { display: block; color: var(--muted); font-size: 0.8rem; }

.top-actions { display: flex; align-items: center; gap: 0.5rem; }

.icon-btn,
.app-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 2.5rem;
  min-width: 2.5rem;
  padding: 0 0.75rem;
  border: 1px solid var(--line);
  border-radius: 0.5rem;
  background: transparent;
  color: var(--ink);
  font: inherit;
  font-size: 0.9rem;
  text-decoration: none;
  cursor: pointer;
}

.menu-btn { display: none; }

.app-link { font-weight: 600; }

.layout {
  display: grid;
  grid-template-columns: var(--sidebar-w) minmax(0, 1fr);
  min-height: calc(100vh - var(--header-h));
}

.sidenav {
  position: sticky;
  top: var(--header-h);
  align-self: start;
  height: calc(100vh - var(--header-h));
  overflow: auto;
  padding: 1.25rem 0.75rem 2rem;
  background: var(--sidebar);
  border-right: 1px solid var(--line);
}

.sidenav h2 {
  margin: 1.25rem 0 0.35rem;
  padding: 0 0.65rem;
  font-family: var(--font);
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--muted);
}

.sidenav a {
  display: block;
  padding: 0.4rem 0.65rem;
  border-radius: 0.35rem;
  color: var(--ink);
  text-decoration: none;
  font-size: 0.95rem;
}
.sidenav a:hover { background: color-mix(in oklch, var(--amber-bright) 16%, transparent); }
.sidenav a[aria-current="page"] {
  background: color-mix(in oklch, var(--amber-bright) 22%, transparent);
  box-shadow: inset 3px 0 0 var(--amber-bright);
  font-weight: 600;
}

.main { min-width: 0; }

article {
  max-width: 42rem;
  margin: 0 auto;
  padding: 2.5rem 1.5rem 4rem;
}

article h1 {
  margin: 0 0 0.75rem;
  font-family: var(--display);
  font-size: clamp(1.85rem, 1.4rem + 1.4vw, 2.4rem);
  font-weight: 650;
  letter-spacing: -0.03em;
  line-height: 1.15;
}

article h2 {
  margin: 2.25rem 0 0.6rem;
  font-family: var(--display);
  font-size: 1.35rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  line-height: 1.25;
}

article h3 {
  margin: 1.5rem 0 0.4rem;
  font-size: 1.05rem;
  font-weight: 650;
}

article p, article li { max-width: 68ch; }
article ul, article ol { padding-left: 1.25rem; }
article li + li { margin-top: 0.35rem; }

.lede { font-size: 1.15rem; color: var(--ink); }

code, .mono {
  font-family: ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  font-size: 0.88em;
}

article code {
  padding: 0.1em 0.35em;
  background: var(--code-bg);
  border-radius: 0.25rem;
}

.rule {
  margin: 1.25rem 0;
  padding: 0.85rem 1rem;
  background: var(--note-bg);
  border-left: 3px solid var(--amber-bright);
  border-radius: 0 0.4rem 0.4rem 0;
}

.table-wrap { overflow-x: auto; margin: 1rem 0 1.5rem; }

table {
  width: max-content;
  min-width: 100%;
  border-collapse: collapse;
  font-size: 0.95rem;
}

th, td {
  text-align: left;
  vertical-align: top;
  padding: 0.55rem 0.7rem;
  border-bottom: 1px solid var(--line);
}

th { font-weight: 650; font-size: 0.85rem; color: var(--muted); }

.directory { list-style: none; padding: 0; margin: 1.5rem 0 0; }
.directory li { margin: 0; padding: 0.85rem 0; border-top: 1px solid var(--line); }
.directory a { font-weight: 650; text-decoration: none; }
.directory p { margin: 0.2rem 0 0; color: var(--muted); }

.pager {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  margin-top: 3rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--line);
}
.pager a { text-decoration: none; font-weight: 600; }
.pager span { display: block; color: var(--muted); font-size: 0.8rem; font-weight: 500; }

.backdrop {
  display: none;
}

.nav-app { display: none; }

@media (max-width: 860px) {
  .topbar {
    flex-wrap: wrap;
    height: auto;
    padding-top: 0.5rem;
    padding-bottom: 0.5rem;
  }
  .search {
    order: 5;
    flex: 1 1 100%;
    max-width: none;
    margin-left: 0;
  }
  .app-link { display: none; }
  .nav-app {
    display: block;
    margin-top: 1.5rem;
    font-weight: 600;
  }
  .menu-btn { display: inline-flex; }
  .layout { grid-template-columns: 1fr; }
  .sidenav {
    position: fixed;
    z-index: 30;
    top: 0;
    left: 0;
    width: min(18rem, 86vw);
    height: 100vh;
    transform: translateX(-105%);
    transition: transform 160ms ease;
  }
  .sidenav.open { transform: none; }
  .backdrop {
    display: block;
    position: fixed;
    inset: 0;
    z-index: 25;
    background: oklch(0.15 0.02 265 / 0.45);
    border: 0;
  }
  .backdrop[hidden] { display: none; }
  article { padding-top: 1.75rem; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .sidenav { transition: none; }
}