:root {
  --bg: #f7f7f5;
  --bg-soft: #ffffff;
  --bg-code: #f1f0ec;
  --fg: #1f2124;
  --fg-soft: #5b6068;
  --fg-faint: #868c95;
  --line: #e2e0da;
  --accent: #b4531f;
  --accent-soft: #f4e6dc;
  --warn: #9a6b00;
  --warn-soft: #fbf1d8;
  --mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
  --sans: "Noto Sans Bengali", "Hind Siliguri", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}
:root[data-theme="dark"] {
  --bg: #16181c;
  --bg-soft: #1d2025;
  --bg-code: #14161a;
  --fg: #e8e6e1;
  --fg-soft: #a9aeb6;
  --fg-faint: #767d87;
  --line: #2c3037;
  --accent: #f08c50;
  --accent-soft: #33241b;
  --warn: #e0b34c;
  --warn-soft: #2b2416;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #16181c;
    --bg-soft: #1d2025;
    --bg-code: #14161a;
    --fg: #e8e6e1;
    --fg-soft: #a9aeb6;
    --fg-faint: #767d87;
    --line: #2c3037;
    --accent: #f08c50;
    --accent-soft: #33241b;
    --warn: #e0b34c;
    --warn-soft: #2b2416;
  }
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 80px; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.85;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
.skip { position: absolute; left: -9999px; }
.skip:focus { left: 12px; top: 12px; background: var(--bg-soft); padding: 8px 14px; z-index: 100; border-radius: 8px; }

/* topbar */
.topbar {
  position: sticky; top: 0; z-index: 40;
  display: flex; align-items: center; gap: 14px;
  height: 62px; padding: 0 18px;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--line);
}
.brand { display: flex; align-items: center; gap: 10px; color: var(--fg); font-weight: 600; }
.brand:hover { text-decoration: none; }
.brand-mark {
  font-family: var(--mono); font-size: 12px; letter-spacing: .08em;
  background: var(--accent); color: #fff; padding: 4px 8px; border-radius: 6px;
}
.brand-text { font-size: 15px; }
.menu-btn, .theme-btn {
  background: none; border: 1px solid var(--line); color: var(--fg-soft);
  border-radius: 8px; width: 36px; height: 34px; cursor: pointer; font-size: 15px;
}
.menu-btn { display: none; }
.menu-btn:hover, .theme-btn:hover { color: var(--fg); border-color: var(--fg-faint); }
.search-wrap { margin-left: auto; position: relative; width: min(360px, 40vw); }
#search {
  width: 100%; padding: 8px 12px; font-family: var(--sans); font-size: 14px;
  color: var(--fg); background: var(--bg-soft);
  border: 1px solid var(--line); border-radius: 9px; outline: none;
}
#search:focus { border-color: var(--accent); }
.results {
  position: absolute; top: 44px; right: 0; width: min(520px, 78vw);
  max-height: 62vh; overflow-y: auto; padding: 6px;
  background: var(--bg-soft); border: 1px solid var(--line);
  border-radius: 12px; box-shadow: 0 18px 40px rgba(0,0,0,.16);
}
.results a { display: block; padding: 9px 11px; border-radius: 8px; color: var(--fg); }
.results a:hover, .results a.sel { background: var(--accent-soft); text-decoration: none; }
.results .r-title { font-size: 14px; font-weight: 600; }
.results .r-page { font-size: 11.5px; color: var(--fg-faint); font-family: var(--mono); }
.results .r-snip { font-size: 13px; color: var(--fg-soft); }
.results mark { background: transparent; color: var(--accent); font-weight: 600; }
.results .empty { padding: 14px; color: var(--fg-faint); font-size: 14px; }

/* layout */
.layout {
  display: grid;
  grid-template-columns: 288px minmax(0, 1fr) 232px;
  gap: 34px; max-width: 1500px; margin: 0 auto; padding: 0 22px;
}
.sidebar {
  position: sticky; top: 62px; align-self: start;
  height: calc(100vh - 62px); overflow-y: auto;
  padding: 22px 4px 60px; border-right: 1px solid var(--line);
}
.nav-link {
  display: flex; flex-direction: column; gap: 1px;
  padding: 8px 12px; border-radius: 9px; color: var(--fg-soft);
  border-left: 2px solid transparent; font-size: 14.5px;
}
.nav-link em { font-style: normal; font-size: 11.5px; color: var(--fg-faint); font-family: var(--mono); }
.nav-link:hover { background: var(--bg-soft); color: var(--fg); text-decoration: none; }
.nav-link.active { color: var(--accent); background: var(--accent-soft); font-weight: 600; }
.nav-sub { list-style: none; margin: 2px 0 10px; padding-left: 16px; border-left: 1px solid var(--line); }
.nav-sub a { display: block; padding: 4px 10px; font-size: 13.5px; color: var(--fg-soft); }
.nav-sub a:hover { color: var(--accent); text-decoration: none; }

main { min-width: 0; padding: 30px 0 80px; }
.toc {
  position: sticky; top: 62px; align-self: start;
  height: calc(100vh - 62px); overflow-y: auto; padding: 30px 0 60px;
}
.toc-title { font-size: 11.5px; letter-spacing: .1em; text-transform: uppercase; color: var(--fg-faint); font-family: var(--mono); margin: 0 0 8px; }
.toc ul { list-style: none; margin: 0; padding: 0; border-left: 1px solid var(--line); }
.toc a { display: block; padding: 4px 12px; font-size: 13px; color: var(--fg-soft); line-height: 1.6; }
.toc a:hover { color: var(--accent); text-decoration: none; }
.toc li.lvl3 a { padding-left: 24px; font-size: 12.5px; }
.toc a.current { color: var(--accent); box-shadow: inset 2px 0 var(--accent); }

/* prose */
.prose h1 { font-size: 30px; line-height: 1.45; margin: 6px 0 22px; letter-spacing: -.01em; }
.prose h2 {
  font-size: 22px; margin: 46px 0 14px; padding-top: 18px;
  border-top: 1px solid var(--line);
}
.prose h3 { font-size: 18px; margin: 30px 0 10px; color: var(--fg); }
.prose h4 { font-size: 16px; margin: 22px 0 8px; color: var(--fg-soft); }
.prose p { margin: 0 0 16px; }
.prose ul, .prose ol { margin: 0 0 18px; padding-left: 24px; }
.prose li { margin: 5px 0; }
.prose hr { border: 0; border-top: 1px solid var(--line); margin: 34px 0; }
.anchor { margin-left: 8px; color: var(--fg-faint); opacity: 0; font-weight: 400; font-size: .7em; }
h1:hover .anchor, h2:hover .anchor, h3:hover .anchor { opacity: 1; text-decoration: none; }
code {
  font-family: var(--mono); font-size: .84em;
  background: var(--bg-code); border: 1px solid var(--line);
  padding: 1px 5px; border-radius: 5px; word-break: break-word;
}
.code-block {
  margin: 0 0 20px; border: 1px solid var(--line); border-radius: 11px;
  overflow: hidden; background: var(--bg-code);
}
.code-head {
  display: flex; justify-content: space-between; align-items: center;
  padding: 6px 12px; border-bottom: 1px solid var(--line);
  font-family: var(--mono); font-size: 11px; letter-spacing: .08em; color: var(--fg-faint);
}
.copy {
  font-family: var(--sans); font-size: 12px; cursor: pointer;
  background: none; border: 1px solid var(--line); color: var(--fg-soft);
  padding: 2px 10px; border-radius: 6px;
}
.copy:hover { color: var(--accent); border-color: var(--accent); }
.code-block pre { margin: 0; padding: 14px 16px; overflow-x: auto; }
.code-block code {
  background: none; border: 0; padding: 0; font-size: 13.5px; line-height: 1.75;
  white-space: pre; display: block;
}
.cmt { color: var(--fg-faint); font-style: italic; }
blockquote.callout {
  margin: 0 0 20px; padding: 14px 18px;
  background: var(--warn-soft); border: 1px solid color-mix(in srgb, var(--warn) 32%, transparent);
  border-left: 3px solid var(--warn); border-radius: 10px;
}
blockquote.callout p:last-child, blockquote.callout ol:last-child, blockquote.callout ul:last-child { margin-bottom: 0; }
.table-wrap { overflow-x: auto; margin: 0 0 22px; border: 1px solid var(--line); border-radius: 11px; }
table { border-collapse: collapse; width: 100%; font-size: 14.5px; }
th, td { padding: 9px 14px; text-align: left; border-bottom: 1px solid var(--line); vertical-align: top; }
th { background: var(--bg-soft); font-weight: 600; font-size: 13.5px; color: var(--fg-soft); white-space: nowrap; }
tr:last-child td { border-bottom: 0; }
td:first-child { white-space: normal; }

/* pagination */
.pagination { display: flex; gap: 14px; margin: 40px 0 0; flex-wrap: wrap; }
.pn {
  flex: 1 1 220px; padding: 12px 16px; border: 1px solid var(--line);
  border-radius: 11px; color: var(--fg); background: var(--bg-soft);
  display: flex; flex-direction: column; gap: 2px;
}
.pn:hover { border-color: var(--accent); text-decoration: none; }
.pn em { font-style: normal; font-size: 11.5px; color: var(--fg-faint); font-family: var(--mono); }
.pn.next { text-align: right; }

/* landing extras (index page) */
.hero-stats { display: flex; flex-wrap: wrap; gap: 12px; margin: 0 0 26px; }
.hero-stats div {
  flex: 1 1 120px; padding: 12px 16px; background: var(--bg-soft);
  border: 1px solid var(--line); border-radius: 11px;
}
.hero-stats b { display: block; font-size: 24px; font-family: var(--mono); color: var(--accent); }
.hero-stats span { font-size: 12.5px; color: var(--fg-faint); }

.scrim { display: none; }
@media (max-width: 1180px) {
  .layout { grid-template-columns: 268px minmax(0, 1fr); }
  .toc { display: none; }
}
@media (max-width: 860px) {
  .layout { grid-template-columns: minmax(0, 1fr); padding: 0 16px; }
  .menu-btn { display: block; }
  .brand-text { display: none; }
  .search-wrap { width: auto; flex: 1; }
  .sidebar {
    position: fixed; top: 62px; left: 0; z-index: 35;
    width: 292px; max-width: 86vw; background: var(--bg);
    transform: translateX(-104%); transition: transform .18s ease;
    padding: 18px 14px 60px;
  }
  body.nav-open .sidebar { transform: none; }
  body.nav-open .scrim {
    display: block; position: fixed; inset: 62px 0 0 0;
    background: rgba(0,0,0,.45); z-index: 30;
  }
  body { font-size: 16px; }
  .prose h1 { font-size: 25px; }
  .prose h2 { font-size: 20px; }
}