/* Edge Build Labs — one stylesheet, no build, no CDN.
   Theme: light by default; dark when the visitor chose it (html[data-theme="dark"])
   or, with no choice stored, when the system prefers dark. */

:root {
  color-scheme: light;
  --bg:        #fbfaf7;
  --bg-panel:  #f3f1ec;
  --ink:       #1c1a17;
  --ink-soft:  #55504a;
  --ink-faint: #8a837a;
  --rule:      #ddd8cf;
  --accent:    #7a5c2e;
  --accent-ink:#5d4522;
  --icon-sun:  none;
  --icon-moon: block;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
  --sans: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --serif: Georgia, "Iowan Old Style", "Palatino Linotype", "Times New Roman", serif;
}

/* The dark set appears twice on purpose: once for the explicit choice, once for
   the system preference when nothing was chosen. Keep both in sync. */
:root[data-theme="dark"] {
  color-scheme: dark;
  --bg:        #14130f;
  --bg-panel:  #1d1b16;
  --ink:       #ece7dd;
  --ink-soft:  #b3aca0;
  --ink-faint: #7e776c;
  --rule:      #33302a;
  --accent:    #d7b174;
  --accent-ink:#e6c68f;
  --icon-sun:  block;
  --icon-moon: none;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    color-scheme: dark;
    --bg:        #14130f;
    --bg-panel:  #1d1b16;
    --ink:       #ece7dd;
    --ink-soft:  #b3aca0;
    --ink-faint: #7e776c;
    --rule:      #33302a;
    --accent:    #d7b174;
    --accent-ink:#e6c68f;
    --icon-sun:  block;
    --icon-moon: none;
  }
}

* { box-sizing: border-box; }

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.65;
}

.wrap {
  max-width: 44rem;
  margin: 0 auto;
  padding: 0 1.4rem;
}

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

header {
  border-bottom: 1px solid var(--rule);
  padding: 3.2rem 0 2.2rem;
}

.brand {
  font-family: var(--serif);
  font-size: 1.9rem;
  line-height: 1.15;
  letter-spacing: -0.01em;
  margin: 0 0 0.5rem;
}

.brand span { color: var(--accent-ink); }

.tagline {
  margin: 0;
  color: var(--ink-soft);
  font-size: 1.08rem;
  max-width: 34rem;
}

nav.lang {
  display: flex;
  align-items: center;
  margin-top: 1.6rem;
  font-size: 0.86rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--ink-faint);
}

nav.lang a { color: var(--ink-faint); text-decoration: none; }
nav.lang a:hover { color: var(--accent-ink); text-decoration: underline; }
nav.lang strong { color: var(--ink); font-weight: 600; }
nav.lang .sep { opacity: 0.4; padding: 0 0.45rem; }

/* ---------- theme switch (shown only when the script is running) ---------- */

.theme-toggle { display: none; }

html.js .theme-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin-left: auto;
  width: 2.1rem;
  height: 2.1rem;
  padding: 0;
  border: 1px solid var(--rule);
  border-radius: 999px;
  background: transparent;
  color: var(--ink-faint);
  cursor: pointer;
  -webkit-appearance: none;
  appearance: none;
}

.theme-toggle:hover { color: var(--accent-ink); border-color: var(--accent); }
.theme-toggle:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

.theme-toggle svg {
  width: 1.05rem;
  height: 1.05rem;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.theme-toggle .sun  { display: var(--icon-sun); }
.theme-toggle .moon { display: var(--icon-moon); }

/* ---------- sections ---------- */

main { padding: 2.6rem 0 1rem; }

section { margin: 0 0 2.9rem; }

h2 {
  font-family: var(--serif);
  font-size: 1.28rem;
  font-weight: 600;
  letter-spacing: -0.005em;
  margin: 0 0 0.7rem;
}

p { margin: 0 0 1rem; }

a { color: var(--accent-ink); }
a:hover { text-decoration-thickness: 2px; }

strong { font-weight: 640; }

.lead { font-size: 1.06rem; }

.quiet { color: var(--ink-soft); }

/* ---------- the rule block ---------- */

blockquote.rule {
  margin: 1.4rem 0;
  padding: 1.1rem 1.3rem;
  background: var(--bg-panel);
  border-left: 3px solid var(--accent);
  border-radius: 2px;
}

blockquote.rule p { margin: 0; font-size: 1.03rem; }

/* ---------- ladder ---------- */

.ladder {
  font-family: var(--mono);
  font-size: 0.92rem;
  background: var(--bg-panel);
  border: 1px solid var(--rule);
  border-radius: 3px;
  padding: 0.85rem 1rem;
  margin: 1.2rem 0;
  overflow-x: auto;
  white-space: nowrap;
  color: var(--ink-soft);
}

.ladder b { color: var(--ink); font-weight: 600; }

/* ---------- fact list ---------- */

ul.facts {
  list-style: none;
  margin: 1rem 0;
  padding: 0;
}

ul.facts li {
  padding: 0.5rem 0 0.5rem 1.1rem;
  border-top: 1px solid var(--rule);
  position: relative;
}

ul.facts li:last-child { border-bottom: 1px solid var(--rule); }

ul.facts li::before {
  content: "\2014";
  position: absolute;
  left: 0;
  color: var(--ink-faint);
}

code {
  font-family: var(--mono);
  font-size: 0.88em;
  background: var(--bg-panel);
  padding: 0.08em 0.34em;
  border-radius: 3px;
}

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

footer {
  border-top: 1px solid var(--rule);
  margin-top: 1.5rem;
  padding: 1.8rem 0 3rem;
  color: var(--ink-faint);
  font-size: 0.9rem;
}

footer a { color: var(--ink-soft); }

/* ---------- small screens ---------- */

@media (max-width: 30rem) {
  body { font-size: 16px; }
  header { padding-top: 2.4rem; }
  .brand { font-size: 1.6rem; }
}

@media (prefers-reduced-motion: no-preference) {
  a { transition: color 120ms ease; }
}