/* site/nav.css
   The sidebar (<site-nav>) and the contents page (<site-toc>), both built by site/nav.js.
   Uses the colour tokens every phase's lesson.css defines (--bg, --fg, --muted, --rule, --accent,
   --accent-soft, --code-bg, --ok, --ok-soft); link this after that stylesheet. */

/* ---- the sidebar ---- */
site-nav { display: block; font-size: .85rem; line-height: 1.45; }
site-nav a { color: inherit; text-decoration: none; }
site-nav a:hover .site-nav-title { text-decoration: underline; text-decoration-thickness: 1px; text-underline-offset: 2px; }
.site-nav-bar { display: flex; align-items: baseline; justify-content: space-between; gap: 1rem; }
.site-nav-home { font-variant: small-caps; letter-spacing: .08em; font-weight: 600; color: var(--accent); }
.site-nav-toggle { font: inherit; font-size: .85rem; padding: .25rem .7rem; border: 1px solid var(--rule); border-radius: 4px; background: var(--bg); color: var(--fg); cursor: pointer; }
.site-nav-toggle[aria-expanded="true"] { background: var(--accent-soft); border-color: var(--accent); }
.site-nav-phase h2 { font-size: .72rem; font-weight: 600; letter-spacing: .06em; text-transform: uppercase; color: var(--muted); margin: 1.5rem 0 .4rem; line-height: 1.3; }
.site-nav-phase-n { color: var(--accent); }
.site-nav-series { font-size: .8rem; font-weight: 400; font-style: italic; color: var(--muted); margin: .9rem 0 .2rem; }
.site-nav-list ul { list-style: none; margin: 0; padding: 0; }
.site-nav-list li { margin: 0; }
.site-nav-list li a { display: grid; grid-template-columns: 1.3rem minmax(0, 1fr) auto; gap: .35rem; align-items: baseline; padding: .22rem .45rem; border-radius: 4px; }
.site-nav-reference li a { grid-template-columns: minmax(0, 1fr); }
.site-nav-list li a:hover { background: var(--code-bg); }
.site-nav-list li a[aria-current="page"] { background: var(--accent-soft); color: var(--accent); font-weight: 600; }
.site-nav-n { color: var(--muted); text-align: right; font-variant-numeric: tabular-nums; }
.site-nav-list a[aria-current="page"] .site-nav-n { color: inherit; }
.site-nav-tick { color: var(--ok); font-weight: 600; }

/* wide screens: a sticky column to the left of the page */
@media (min-width: 70rem) {
  body.has-site-nav { display: grid; grid-template-columns: 17rem minmax(0, 1fr); align-items: start; }
  site-nav { position: sticky; top: 0; height: 100vh; overflow-y: auto; padding: 2.25rem 1.1rem 2rem 1.5rem; border-right: 1px solid var(--rule); }
  .site-nav-toggle { display: none; }
}
/* narrow screens: a bar across the top; the list drops down from the Contents button */
@media (max-width: 69.99rem) {
  site-nav { position: sticky; top: 0; z-index: 10; background: var(--bg); border-bottom: 1px solid var(--rule); padding: .6rem 1.25rem; }
  .site-nav-list { display: none; max-height: 70vh; overflow-y: auto; padding: 0 0 .75rem; }
  site-nav.open .site-nav-list { display: block; }
  .site-nav-phase h2 { margin-top: 1rem; }
}

/* ---- the contents page ---- */
site-toc { display: block; }
.toc-continue { background: var(--ok-soft); color: var(--ok); border-radius: 6px; padding: .6rem .9rem; margin: 1.5rem 0; }
.toc-continue a { color: inherit; font-weight: 600; }
.toc-phase, .toc-later { margin: 2.5rem 0 0; }
.toc-phase h2, .toc-later h2 { margin: 0 0 .3rem; }
.toc-phase-n { font-variant: small-caps; letter-spacing: .08em; color: var(--accent); }
.toc-phase h2 .toc-phase-n { display: block; font-size: 1rem; }
.toc-why { font-style: italic; color: var(--muted); margin: 0 0 1rem; }
.toc-series { font-size: 1rem; font-weight: 400; font-style: italic; color: var(--muted); margin: 1.5rem 0 .25rem; }
site-toc ul.toc-lessons, site-toc ul.toc-reference, site-toc ul.toc-later-list { list-style: none; padding: 0; margin: 0; }
site-toc ul.toc-lessons > li { margin: 0; }
.toc-lesson { display: grid; grid-template-columns: 2.4rem minmax(0, 1fr); gap: .6rem; padding: .7rem .6rem .75rem .3rem; border-top: 1px solid var(--rule); border-radius: 0 6px 6px 0; color: inherit; text-decoration: none; }
site-toc ul.toc-lessons > li:last-child .toc-lesson { border-bottom: 1px solid var(--rule); }
.toc-lesson:hover { background: var(--code-bg); }
.toc-n { font-size: 1.5rem; line-height: 1.15; text-align: right; color: var(--accent); font-variant-numeric: tabular-nums; }
.toc-body { display: block; min-width: 0; }
.toc-title { display: block; font-size: 1.1rem; line-height: 1.3; }
.toc-lesson:hover .toc-title { text-decoration: underline; text-decoration-thickness: 1px; text-underline-offset: 2px; }
.toc-blurb { display: block; font-size: .92rem; color: var(--muted); margin-top: .15rem; }
.toc-meta { display: block; font-size: .78rem; letter-spacing: .05em; text-transform: uppercase; color: var(--muted); margin-top: .35rem; }
.toc-done { color: var(--ok); font-weight: 600; }
site-toc ul.toc-reference > li { margin: .3rem 0; }
.toc-from { color: var(--muted); font-size: .92rem; }
.toc-later { color: var(--muted); }
site-toc ul.toc-later-list > li { margin: .45rem 0; }
.toc-later strong { font-weight: 600; color: var(--fg); }
.toc-later-why { font-size: .92rem; }

@media print {
  site-nav { display: none; }
  body.has-site-nav { display: block; }
  .toc-lesson:hover, .site-nav-list li a:hover { background: none; }
}