/* A wider page than tabi's default (1000px): text and code blocks share it;
   tighter line spacing in articles (tabi: double-spaced); tables left-aligned. */
:root {
  --max-layout-width: 1200px;
}

article p,
article li {
  line-height: 1.6;
}

/* Table text aligned left (tabi centres it). */
article table,
article table th {
  text-align: start;
}

/* Section levels that are easy to tell apart: h2 larger, with a rule above
   and more space; h3 smaller and closer to its text. */
article h2 {
  font-size: 1.55rem;
  margin-top: 2.2em;
  padding-top: 0.7em;
  border-top: 1px solid var(--divider-color);
}

article h3 {
  font-size: 1.12rem;
  margin-top: 1.6em;
}

/* The same gap under every heading, whatever follows it: tabi gives
   paragraphs a small top margin and lists none. Margins collapse, so the
   heading's bottom margin sets the gap in both cases. */
article :is(h2, h3, h4) {
  margin-bottom: 0.8rem;
}

/* The first section (Overview) sits right under the title and the table
   of contents: no rule or extra space above it. */
article section.body > h2:first-child {
  border-top: none;
  margin-top: 0;
  padding-top: 0;
}

/* A smaller site title than tabi's (1.7em). */
header .home-title {
  font-size: 1.25em;
}

/* A soft gradient behind the header, from the page background down to a dim
   tint of the accent colour, with a 2px line at the bottom, in both themes.
   The border-image outset paints it across the whole window without widening
   the page (no horizontal scroll). */
header {
  border-image: linear-gradient(
      to bottom,
      var(--background-color),
      color-mix(in srgb, var(--primary-color) 14%, var(--background-color)) calc(100% - 2px),
      color-mix(in srgb, var(--primary-color) 45%, var(--background-color)) calc(100% - 2px)
    )
    fill 0 / 0 / 0 100vmax;
  margin-bottom: 1.5rem;
}

/* Series navigation (templates/components/series_page.html): an "All parts"
   heading like "Table of contents", and below it the parts in one row,
   "Part 1 · Part 2 · …", the current part in bold. */
.series-page-intro {
  margin-block-end: 3.5rem;
}

.series-page-intro h3 {
  margin-top: 0.6rem;
  margin-bottom: 0.3rem;
}

/* Under the date line, the series block follows directly. */
article:has(.series-page-intro) ul.meta {
  margin-bottom: 0;
}

/* The browser closes tabi's <p> before the heading and the list. */
.series-page-intro p:empty {
  display: none;
}

.series-page-intro ul {
  display: flex;
  flex-wrap: wrap;
  gap: 0.3rem 0.8rem;
  margin: 0;
  padding: 0;
}

.series-page-intro li {
  list-style: none;
}

.series-page-intro li + li::before {
  content: "·";
  margin-inline-end: 0.8rem;
  color: var(--meta-color);
}

.series-page-intro li[aria-current="page"] {
  font-weight: 600;
}