/* Analysis solutions -- /math/analysis/ and every section page under it.
 *
 * This duplicates about thirty lines of body typography from paper.css rather
 * than extending it. paper.css says at the top that it is generated: the hog
 * repo's build-html.js copies over it, so building forty pages on top of it
 * would mean a rebuild in another repo silently restyling this section. A
 * generated file is a bad base class.
 *
 * What it deliberately does NOT copy is the paper title block. A page titled
 * "2.6" is a location in a book, not a headline, so the display title, deck and
 * uppercase byline are replaced by a breadcrumb and a small heading.
 */

.solution {
  --ink: #0b0b0b;
  --soft: #52514e;
  --faint: #8a8880;
  --rule: #e6e5e0;
  --accent: #007acc;
  --amber: #a86300; /* dark enough to clear 4.5:1 on white; true orange next
                       to Charter reads as an error state */

  --serif: Charter, "Bitstream Charter", "Iowan Old Style", "Source Serif Pro",
    Georgia, Cambria, "Times New Roman", serif;
  --sans: var(--font);
}

@media (prefers-color-scheme: dark) {
  .solution {
    --ink: #ededea;
    --soft: #c3c2b7;
    --faint: #8a8880;
    --rule: #333330;
    --accent: #3987e5;
    --amber: #d99a3a;
  }
}

.solution {
  max-width: 40em;
  margin-inline: auto;
  color: var(--ink);
  font-family: var(--serif);
  font-size: 1.0625rem;
  line-height: 1.62;
  font-kerning: normal;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

.solution p { margin: 0 0 1.15rem; }

/* One "## Exercise 2.5.5" per problem. style.css sets h2 to 1.5em at normal
   weight, which is a page heading; here it separates problems inside one, and
   kramdown gives each an id so a single exercise can be linked to. */
.solution h2 {
  margin: 2.75rem 0 1rem;
  font-family: var(--serif);
  font-size: 1.3rem;
  font-weight: 650;
  line-height: 1.25;
  letter-spacing: -0.012em;
}

.solution h2:first-child { margin-top: 0; }
.solution a { color: var(--accent); }
.solution strong { font-weight: 650; }

/* ---------- header ---------- */

.sol-header { margin: 1.75rem 0 2.25rem; }

.sol-crumb {
  margin: 0 0 0.5rem;
  font-family: var(--sans);
  font-size: 0.74rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--faint);
}

.sol-crumb a { color: var(--faint); text-decoration: none; }
.sol-crumb a:hover { color: var(--ink); text-decoration: none; }

.sol-title {
  /* style.css underlines every h1 and sets it at 2.4em; this heading carries
     the section, not the page, so it steps well down and takes its own rule. */
  margin: 0;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--rule);
  font-family: var(--serif);
  font-size: 1.6rem;
  font-weight: 650;
  line-height: 1.2;
  letter-spacing: -0.012em;
}

/* ---------- callouts ---------- */

/* Obsidian's callouts are saturated by default. Here the exercise card is the
 * quiet neutral one and colour is reserved for the annotations, so the loudest
 * thing on the page is what I added rather than what the book said.
 *
 * One tint per type, mixed against transparent so it darkens a light surface
 * and lightens a dark one by the same amount -- the same trick style.css uses
 * for blockquote, and the reason there is no dark-mode copy of these rules.
 */

.callout {
  --tint: var(--faint);
  margin: 1.9rem 0;
  padding: 0.95rem 1.15rem 0.15rem;
  border: 1px solid var(--rule);
  border-left: 3px solid var(--tint);
  border-radius: 6px;
  background: rgba(127, 127, 127, 0.06);
}

@supports (color: color-mix(in srgb, red 50%, transparent)) {
  .callout { background: color-mix(in srgb, var(--tint) 7%, transparent); }
}

.callout--idea  { --tint: var(--accent); }
.callout--stuck { --tint: var(--amber); }

.callout-label {
  display: flex;
  align-items: center;
  gap: 0.5em;
  margin: 0 0 0.55rem;
  font-family: var(--sans);
  font-size: 0.71rem;
  font-weight: 600;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  color: var(--tint);
}

.callout-label svg { width: 0.95em; height: 0.95em; flex: none; }
.callout > :last-child { margin-bottom: 0.8rem; }

/* ---------- math ---------- */

/* KaTeX is pre-rendered by script/build-notes, so no JS runs here. It draws in
 * currentColor and follows --ink into dark mode with no override. */

.solution .katex { font-size: 1.06em; }

/* build-notes wraps display math in this so kramdown treats it as a block and
 * does not put it in a paragraph of its own. The spacing lives on .katex-display
 * below, so the wrapper contributes none. */
.solution .math-block { margin: 0; }

/* Long display lines scroll on their own instead of widening the page.
 * See https://github.com/KaTeX/KaTeX/issues/1023 */
.solution .katex-display {
  margin: 1.5rem 0;
  padding: 0.35rem 0.15rem;
  overflow-x: auto;
  overflow-y: hidden;
}

/* ---------- footer ---------- */

.sol-attrib {
  margin: 3rem 0 0;
  font-family: var(--sans);
  font-size: 0.8rem;
  line-height: 1.5;
  color: var(--faint);
}

.sol-nav {
  display: flex;
  justify-content: space-between;
  gap: 1.5rem;
  margin-top: 1.25rem;
  padding-top: 1rem;
  border-top: 1px solid var(--rule);
  font-family: var(--sans);
  font-size: 0.82rem;
}

.sol-next { text-align: right; }

@media (max-width: 34em) {
  .solution { font-size: 1rem; }
  .sol-nav { flex-direction: column; gap: 0.5rem; }
  .sol-next { text-align: left; }
}