/* ============================================================ site structure

   Three columns on wide screens: navigation, content, then contents and
   metadata. Collapses to one on narrow screens, dropping the least essential
   column first. Loaded after style.css, which owns the palette and typography. */

.shell { max-width: 88rem; margin: 0 auto; display: block; }
.shell.has-nav,
.shell.has-rail {
  display: grid;
  gap: 0 2.5rem;
  align-items: start;
  padding: 0 clamp(1rem, 3vw, 2rem);
}
.shell.has-nav { grid-template-columns: 17rem minmax(0, 1fr); }
body.wide .shell.has-nav { grid-template-columns: 17rem minmax(0, 1fr) 15rem; }

/* Guides and concept pages: contents list, but no navigation tree. Without a
   column of its own the rail is just the last block element in the shell, which
   is how the contents list ended up printed underneath the article. */
.shell.has-rail:not(.has-nav) { grid-template-columns: minmax(0, 1fr) 15rem; }

.shell.has-nav > main { padding-left: 0; padding-right: 0; }
.shell:not(.has-nav) > main { margin: 0 auto; }

/* Why `min(…, 100%)` rather than a bare max-width.

   `margin: 0 auto` on a grid item switches off stretch alignment, so the item
   is sized shrink-to-fit — and shrink-to-fit floors at min-content, which for a
   page holding a wide code block is the longest line of that block. <main>
   therefore grew past its own column and pushed the whole document sideways on
   every screen under ~700px, instead of the code scrolling inside itself the way
   `pre { overflow: auto }` intends. A max-width is applied after that floor, so
   clamping it to the container is what actually contains the page.

   `min-width: 0` is here for the same reason from the other direction: grid
   items default to `min-width: auto` and refuse to shrink below their content. */
.shell.has-nav > main,
.shell.has-rail > main { min-width: 0; }
.shell.has-nav > main,
.shell.has-rail:not(.has-nav) > main { max-width: min(var(--measure), 100%); }
/* The home page is the one rail page that wants the full width for its card grid. */
body.wide .shell.has-rail:not(.has-nav) > main { max-width: min(76rem, 100%); }
.rail-col { position: sticky; top: 4.75rem; padding-top: 2.5rem; min-width: 0; }

/* ------------------------------------------------------------- sidebar nav */

.sidebar {
  position: sticky; top: 4.75rem;
  max-height: calc(100vh - 6rem);
  overflow-y: auto;
  padding: 2rem 0.5rem 3rem 0;
  font-size: 0.86rem;
  border-right: 1px solid var(--border);
}
.sidebar ul { list-style: none; margin: 0; padding: 0; }
.sidebar a { display: block; padding: 0.22rem 0.5rem; border-radius: 6px; color: var(--muted); }
.sidebar a:hover { background: var(--surface-2); color: var(--text); text-decoration: none; }
.sidebar a[aria-current="page"] { background: var(--accent-soft); color: var(--link); font-weight: 600; }
.sidebar summary {
  cursor: pointer; padding: 0.35rem 0.5rem; border-radius: 6px;
  font-weight: 600; color: var(--text); list-style: none;
}
.sidebar summary::-webkit-details-marker { display: none; }
.sidebar summary::before {
  content: "\25B8"; display: inline-block; width: 1em;
  color: var(--muted); transition: transform 0.12s;
}
.sidebar details[open] > summary::before { transform: rotate(90deg); }
.sidebar summary:hover { background: var(--surface-2); }
.nav-id { color: var(--muted); font-weight: 500; font-size: 0.78em; margin-right: 0.15rem; }
.nav-family > a { font-weight: 550; color: var(--text); margin-top: 0.35rem; }
.nav-family > ul { border-left: 1px solid var(--border); margin-left: 0.65rem; padding-left: 0.4rem; }
.nav-domain > details > ul { padding-left: 0.55rem; }

/* --------------------------------------------------------------------- TOC */

.toc {
  font-size: 0.82rem; padding-bottom: 1.5rem;
  margin-bottom: 1.25rem; border-bottom: 1px solid var(--border);
}
.toc-title {
  margin: 0 0 0.5rem; font-size: 0.7rem; text-transform: uppercase;
  letter-spacing: 0.07em; color: var(--muted); font-weight: 650;
}
.toc ul { list-style: none; margin: 0; padding: 0; }
.toc li { margin: 0.1rem 0; }
.toc a {
  display: block; padding: 0.16rem 0 0.16rem 0.6rem;
  border-left: 2px solid var(--border); color: var(--muted);
}
.toc a:hover { color: var(--text); border-left-color: var(--border-strong); text-decoration: none; }
.toc a[aria-current] { color: var(--link); border-left-color: var(--accent); font-weight: 550; }

/* ---------------------------------------------------------- heading anchors */

h2, h3 { scroll-margin-top: 5rem; }
.anchor {
  margin-left: 0.4rem; color: var(--muted); opacity: 0; font-weight: 400;
  text-decoration: none; transition: opacity 0.12s;
}
h2:hover .anchor, h3:hover .anchor, .anchor:focus { opacity: 1; }

/* -------------------------------------------------------- header search box */

.site-search { position: relative; flex: 1 1 16rem; max-width: 26rem; }
.site-search input {
  width: 100%; padding: 0.42rem 2.2rem 0.42rem 0.75rem;
  font: inherit; font-size: 0.88rem; color: inherit;
  background: var(--surface-2); border: 1px solid var(--border); border-radius: 8px;
}
.site-search input:focus { outline: 2px solid var(--accent); outline-offset: 1px; background: var(--surface); }
.site-search kbd {
  position: absolute; right: 0.55rem; top: 50%; transform: translateY(-50%);
  font-family: inherit; font-size: 0.7rem; color: var(--muted);
  border: 1px solid var(--border-strong); border-radius: 4px;
  padding: 0 0.3rem; pointer-events: none;
}
.site-search input:focus + kbd { display: none; }
.site-search #results {
  position: absolute; top: calc(100% + 0.4rem); left: 0; right: 0; z-index: 20;
  list-style: none; margin: 0; padding: 0; max-height: 24rem; overflow-y: auto;
  background: var(--surface); border: 1px solid var(--border-strong);
  border-radius: 10px; box-shadow: 0 8px 28px rgba(0, 0, 0, 0.18);
}
.site-search #results li + li { border-top: 1px solid var(--border); }
.site-search #results a { display: block; padding: 0.55rem 0.8rem; color: inherit; font-size: 0.88rem; }
.site-search #results a:hover,
.site-search #results a:focus { background: var(--surface-2); text-decoration: none; outline: none; }
.site-search .where { display: block; color: var(--muted); font-size: 0.76rem; }
.site-search .empty { padding: 0.7rem 0.8rem; color: var(--muted); font-size: 0.86rem; }

/* ------------------------------------------------------------- copy button */

figure.code { position: relative; }
figure.code figcaption { display: flex; align-items: center; justify-content: space-between; gap: 1rem; }
button.copy {
  font: inherit; font-size: 0.68rem; letter-spacing: 0.04em; text-transform: uppercase;
  padding: 0.15rem 0.5rem; border-radius: 5px; cursor: pointer;
  color: var(--muted); background: var(--surface); border: 1px solid var(--border-strong);
}
button.copy:hover { color: var(--text); border-color: var(--accent); }
button.copy.done { color: var(--ok-fg); border-color: var(--ok-fg); }
figure.code > button.copy { position: absolute; top: 0.5rem; right: 0.5rem; z-index: 2; }

/* --------------------------------------------- family list, related, pager */

ol.family-list { list-style: none; counter-reset: fam; margin: 0; padding: 0; }
ol.family-list li {
  counter-increment: fam; position: relative;
  padding: 0.9rem 0 0.9rem 2.4rem; border-bottom: 1px solid var(--border);
}
ol.family-list li::before {
  content: counter(fam); position: absolute; left: 0; top: 1rem;
  width: 1.6rem; height: 1.6rem; border-radius: 50%;
  background: var(--surface-2); color: var(--muted);
  font-size: 0.75rem; font-weight: 650; display: grid; place-items: center;
}
ol.family-list p { margin: 0.25rem 0; color: var(--muted); font-size: 0.9rem; }
ol.family-list code { color: var(--muted); background: none; padding: 0; font-size: 0.82rem; }

ul.related { list-style: none; margin: 0.5rem 0 0; padding: 0; }
ul.related li { padding: 0.5rem 0; border-bottom: 1px solid var(--border); }
ul.related span { display: block; color: var(--muted); font-size: 0.86rem; }

.pager { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; margin: 2.5rem 0 0; }
.pager a {
  display: block; padding: 0.85rem 1rem; border: 1px solid var(--border);
  border-radius: var(--radius); color: inherit; font-weight: 550;
}
.pager a:hover { border-color: var(--accent); text-decoration: none; }
.pager a.next { text-align: right; }
.pager span {
  display: block; font-size: 0.72rem; text-transform: uppercase;
  letter-spacing: 0.06em; color: var(--muted); font-weight: 600; margin-bottom: 0.15rem;
}

/* --------------------------------------------------------------- provenance */

.provenance {
  margin: 3rem 0 0; padding: 1.15rem 1.3rem;
  background: var(--surface-2); border: 1px solid var(--border);
  border-radius: var(--radius); font-size: 0.88rem; color: var(--muted);
}
.provenance h2 { margin: 0 0 0.5rem; font-size: 0.95rem; color: var(--text); }
.provenance p { margin: 0.45rem 0; }
.provenance .meta-line {
  font-size: 0.82rem; padding-top: 0.5rem;
  border-top: 1px solid var(--border); margin-top: 0.8rem;
}
.card-meta { font-size: 0.78rem !important; margin-top: 0.4rem !important; }

/* ------------------------------------------------------------ machine routes

   The llms.txt slice and the markdown twin of a page. Present for a reader who
   is looking for them, quiet for one who is not. */

.rail ul.links.machine { margin-top: 0.9rem; padding-top: 0.9rem; }
.rail ul.links.machine a { color: var(--muted); }
.rail ul.links.machine a:hover { color: var(--link); }
.machine-line {
  font-size: 0.86rem; color: var(--muted);
  margin: 0 0 2rem; padding: 0.7rem 0.9rem;
  background: var(--surface-2); border: 1px solid var(--border); border-radius: var(--radius);
}
.machine-line code { background: var(--surface); }

/* --------------------------------------------------------------- responsive */

@media (max-width: 78rem) {
  body.wide .shell.has-nav { grid-template-columns: 16rem minmax(0, 1fr); }
  body.wide .shell.has-nav > .rail-col { grid-column: 2; position: static; padding-top: 0; }
  /* The contents list is the only thing in the rail on a page with no sidebar,
     and it is hidden below — so the column goes with it. Placing the rail by
     `grid-column` here would open an implicit second column on those pages. */
  .shell.has-rail:not(.has-nav) { grid-template-columns: minmax(0, 1fr); }
  .toc { display: none; }
}
@media (max-width: 62rem) {
  /* Override the more-specific wide-screen selectors as well. Without these,
     topic pages retain an implicit navigation/content grid on phone widths. */
  .shell.has-nav,
  body.wide .shell.has-nav { grid-template-columns: minmax(0, 1fr); }
  body.wide .shell.has-nav > main { min-width: 0; max-width: 100%; }
  body.wide .shell.has-nav > .rail-col { grid-column: 1; }
  .sidebar {
    position: static; max-height: none; border-right: 0;
    border-bottom: 1px solid var(--border); padding: 1rem 0;
  }
  .sidebar .nav-root > li > details > ul { max-height: 22rem; overflow-y: auto; }
  .site-search { order: 3; flex-basis: 100%; max-width: none; }
}
@media (max-width: 44rem) {
  .pager { grid-template-columns: 1fr; }
  .pager a.next { text-align: left; }
}

/* ------------------------------------------------------------- card polish

   Cards sit in a grid, so a short title next to a long one leaves a ragged
   row. Making each card a column and pushing the meta line to the bottom keeps
   the row visually level whatever the title length. */

.grid .card { display: flex; flex-direction: column; }
.grid .card h3 { margin-bottom: 0.35rem; }
.grid .card p { margin-top: auto; }
.grid .card .tag { margin-bottom: 0.15rem; }