/* ════════════════════════════════════════════════════════════════════
   FR_Math docs — hand-written CSS, no preprocessor, no framework.
   Zero build step. Edit this file, refresh your browser.

   Color palette: stone + amber. Picked to feel like retro engineering
   (resistor amber, PCB soldermask stone) and to be distinct from the
   cool-blue default used by other deftio doc sites.
   ════════════════════════════════════════════════════════════════════ */

:root {
  --fr-bg:         #fafaf9;  /* stone-50  */
  --fr-text:       #1c1917;  /* stone-900 */
  --fr-muted:      #78716c;  /* stone-500 */
  --fr-rule:       #e7e5e4;  /* stone-200 */
  --fr-code-bg:    #f5f5f4;  /* stone-100 */
  --fr-code-border:#d6d3d1;  /* stone-300 */
  --fr-accent:     #b45309;  /* amber-700 */
  --fr-accent-dk:  #92400e;  /* amber-800 */
  --fr-accent-lt:  #fde68a;  /* amber-200 */
  --fr-accent-bg:  #fffbeb;  /* amber-50  */
}

/* ── Reset ────────────────────────────────────────────────────────── */

*, *::before, *::after { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  font: 400 16px/1.55 -apple-system, BlinkMacSystemFont, "Segoe UI",
        Roboto, Helvetica, Arial, sans-serif;
  color: var(--fr-text);
  background-color: var(--fr-bg);
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

h1, h2, h3, h4, h5, h6, p, blockquote, pre, ul, ol, dl, figure, table {
  margin: 0 0 0.8em 0;
}

ul, ol { padding-left: 1.4em; }

/* ── Page frame ───────────────────────────────────────────────────── */

.wrapper {
  max-width: 75%;
  margin: 0 auto;
  padding: 0 20px;
}

@media screen and (max-width: 900px) {
  .wrapper { max-width: 100%; padding: 0 16px; }
}

main.page-content {
  flex: 1;
  padding: 24px 0 48px 0;
}

/* ── Header + nav ─────────────────────────────────────────────────── */

.site-header {
  border-bottom: 2px solid var(--fr-accent-dk);
  background-color: var(--fr-bg);
}

.site-header .wrapper {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  padding-top: 12px;
  padding-bottom: 12px;
}

.site-title,
.site-title:visited {
  font-size: 24px;
  font-weight: 600;
  letter-spacing: -0.5px;
  color: var(--fr-accent-dk);
  text-decoration: none;
}

.site-title:hover { color: var(--fr-accent); }

.site-version {
  font-size: 13px;
  font-weight: 400;
  color: var(--fr-muted);
  margin-left: 6px;
  letter-spacing: 0;
}

.site-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
}

.site-nav a {
  color: var(--fr-text);
  text-decoration: none;
  font-size: 15px;
  line-height: 1.5;
}

.site-nav a:hover,
.site-nav a.active {
  color: var(--fr-accent);
  text-decoration: underline;
}

/* ── Body links ───────────────────────────────────────────────────── */

a { color: var(--fr-accent); }
a:visited { color: var(--fr-accent-dk); }
a:hover { color: var(--fr-text); text-decoration: underline; }

/* ── Headings ─────────────────────────────────────────────────────── */

h1 { font-size: 36px; font-weight: 600; letter-spacing: -0.5px;
     margin-top: 0.3em; margin-bottom: 0.6em; }
h2 { font-size: 26px; font-weight: 600;
     margin-top: 1.8em; }
h3 { font-size: 20px; font-weight: 600; margin-top: 1.4em; }
h4 { font-size: 17px; font-weight: 600; margin-top: 1.2em; }

@media screen and (max-width: 900px) {
  h1 { font-size: 30px; }
  h2 { font-size: 22px; }
}

/* ── Horizontal rules ─────────────────────────────────────────────── */

hr {
  margin: 2em 0;
  border: 0;
  border-top: 1px solid var(--fr-rule);
}

/* ── Tables ───────────────────────────────────────────────────────── */

table {
  width: 100%;
  border-collapse: collapse;
  border: 1px solid var(--fr-rule);
  font-size: 15px;
}

th, td {
  padding: 6px 10px;
  border: 1px solid var(--fr-rule);
  text-align: left;
  vertical-align: top;
}

th {
  background-color: var(--fr-code-bg);
  font-weight: 600;
}

tr:nth-child(even) td { background-color: var(--fr-code-bg); }

/* ── Code ─────────────────────────────────────────────────────────── */

code, pre, kbd, samp {
  font-family: ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  font-size: 0.9em;
}

code {
  background-color: var(--fr-code-bg);
  border: 1px solid var(--fr-code-border);
  border-radius: 3px;
  padding: 1px 5px;
  color: var(--fr-accent-dk);
}

pre {
  background-color: var(--fr-code-bg);
  border: 1px solid var(--fr-code-border);
  border-radius: 4px;
  padding: 12px 16px;
  overflow-x: auto;
}

pre code {
  background: transparent;
  border: 0;
  padding: 0;
  color: inherit;
  font-size: inherit;
}

/* ── Blockquotes (callout boxes) ──────────────────────────────────── */

blockquote {
  margin: 1em 0;
  padding: 8px 14px;
  border-left: 4px solid var(--fr-accent-lt);
  background-color: var(--fr-accent-bg);
  color: var(--fr-text);
}

blockquote > :last-child { margin-bottom: 0; }

/* ── Footer ───────────────────────────────────────────────────────── */

.site-footer {
  border-top: 2px solid var(--fr-rule);
  color: var(--fr-muted);
  font-size: 14px;
  padding: 16px 0;
}

.site-footer a { color: var(--fr-muted); }
.site-footer a:hover { color: var(--fr-accent); }

.site-footer .wrapper {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 10px;
}

/* ── Utility classes used in body copy ────────────────────────────── */

.muted { color: var(--fr-muted); }
.center { text-align: center; }