/* The site is a rule.
   A tape measure runs down the left edge of every page, graduated in
   sixteenths, and the content hangs off it. Section headings sit at their
   measurement — the page is literally measured, which is what the app does.
   Nothing is centred, because nothing on a drawing is centred. */
:root {
  --bg: #0E1013;
  --surface: #15181C;
  --raised: #1B1F24;
  --rule: #22272C;
  --frame: #2C333A;
  --ink: #F4F6F7;
  --ink-2: #B4BBC2;
  --ink-3: #8B949C;
  --accent: #FFA31A;
  --mono: 'IBM Plex Mono', ui-monospace, SFMono-Regular, Menlo, monospace;
  --sans: 'IBM Plex Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --cond: 'IBM Plex Sans Condensed', var(--sans);
  --gutter: 88px;
  --pad: 28px;
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 400 16px/1.65 var(--sans);
  padding-left: var(--gutter);
}

/* ---- the rule down the left edge ---------------------------------------- */
.rule {
  position: fixed;
  inset: 0 auto 0 0;
  width: var(--gutter);
  background: var(--surface);
  border-right: 2px solid var(--accent);
  z-index: 10;
  overflow: hidden;
}
/* Graduations: a long tick every inch, short ones between.
   Drawn with a repeating gradient so there is no markup and no image. */
.rule .ticks {
  position: absolute;
  inset: 0;
  background:
    repeating-linear-gradient(to bottom,
      var(--frame) 0 1px, transparent 1px 16px),
    repeating-linear-gradient(to bottom,
      transparent 0 63px, var(--ink-3) 63px 65px);
  background-position: right 0 top 0;
  background-size: 22px 100%, 40px 100%;
  background-repeat: repeat-y;
  right: 0; left: auto; width: 40px;
  top: 96px;
}
/* The head of the rule, where a tape measure has its hook.
   It is a solid block so the graduations stop underneath it rather than
   running through the mark - the first version put a 44px logo at left:12
   and the ticks at right:0 in an 88px gutter, so the two overlapped by 8px
   and the mark came out looking chipped. */
.rule .brand {
  position: absolute;
  left: 0; top: 0; right: 0;
  height: 96px;
  background: #15181C;
  border-bottom: 2px solid var(--accent);
  display: grid; place-items: center;
  /* The global `a` rule draws a rule under every link. Not under the logo. */
  border-left: 0; border-right: 0; border-top: 0;
  text-decoration: none;
}
.rule .brand img {
  display: block;
  width: 52px; height: 52px;
  transition: transform .18s ease;
}
/* Hover is geometry only. Lightening the plate was the obvious move and it
   was wrong: the icon carries its own dark ground, so the moment the plate
   moved off #15181C the artwork reappeared as a visible square. So instead
   the mark lifts and the zero line thickens, the way a tape hook clicks out.
   The line is a pseudo-element over the border, so nothing reflows. */
.rule .brand::after {
  content: ""; position: absolute; left: 0; right: 0; bottom: -2px;
  height: 2px; background: var(--accent);
  transform: scaleY(1); transform-origin: bottom;
  transition: transform .18s ease;
}
.rule .brand:hover::after { transform: scaleY(2.5); }
.rule .brand:hover img { transform: translateY(-3px); }
.rule .brand:focus-visible { outline: 2px solid var(--accent); outline-offset: -4px; }

.rule .vertical {
  position: absolute;
  left: 20px; top: 132px;
  transform-origin: 0 0;
  transform: rotate(90deg);
  white-space: nowrap;
  font: 700 12px var(--sans);
  letter-spacing: .3em;
  color: var(--ink-3);
}

/* ---- content ------------------------------------------------------------ */
main { max-width: 860px; padding: 30px var(--pad) 140px; }

/* Every band is measured off the rule with its own dimension label. */
section { position: relative; padding: 74px 0 0; }
section > .dim {
  position: absolute;
  left: calc(-1 * (var(--gutter) + var(--pad))); top: 76px;
  width: var(--gutter);
  text-align: center;
  font: 700 10px var(--mono);
  letter-spacing: .1em;
  color: var(--accent);
  background: var(--surface);
  padding: 6px 0;
  z-index: 11;
}

h1 {
  font: 700 clamp(38px, 7.4vw, 76px)/1.02 var(--cond);
  margin: 0 0 22px;
  letter-spacing: -.01em;
}
h1 .mark { color: var(--ink-3); font-weight: 400; }
.lede {
  font: 400 clamp(17px, 2.3vw, 21px)/1.5 var(--sans);
  color: var(--ink-2);
  max-width: 46ch;
  margin: 0 0 30px;
}
h2 {
  font: 700 11px var(--sans);
  letter-spacing: .2em; text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 18px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--rule);
}
h3 { font: 600 17px var(--sans); margin: 0 0 6px; color: var(--ink); }
p, li { color: var(--ink-2); }
p { margin: 0 0 16px; max-width: 62ch; }
ul { padding-left: 18px; margin: 0 0 20px; max-width: 62ch; }
li { margin-bottom: 7px; }
strong { color: var(--ink); font-weight: 600; }
a { color: var(--accent); text-decoration: none; border-bottom: 1px solid rgba(255,163,26,.35); }
a:hover { border-bottom-color: var(--accent); }
code, .num { font-family: var(--mono); color: var(--ink); }

/* The worked example: the whole pitch in four lines of type. */
.sum {
  border-left: 2px solid var(--accent);
  background: var(--surface);
  padding: 22px 24px;
  margin: 0 0 34px;
  font: 700 clamp(19px, 3.4vw, 30px)/1.9 var(--mono);
  overflow-x: auto;
}
.sum span { color: var(--ink-3); font-weight: 400; padding: 0 2px; }
.sum .eq { color: var(--accent); }
.sum small {
  display: block;
  font: 400 13px/1.5 var(--sans);
  color: var(--ink-3);
  margin-top: 12px;
}

/* Rows share the app's list anatomy: a rule above, no card, no radius. */
.rows { border-bottom: 1px solid var(--rule); }
.row {
  border-top: 1px solid var(--rule);
  padding: 17px 0;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 6px 22px;
  align-items: baseline;
}
.row p { margin: 0; grid-column: 1 / -1; color: var(--ink-3); font-size: 15px; }
.row .val { font: 500 15px var(--mono); color: var(--ink-3); text-align: right; }

.grid2 { display: grid; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); gap: 1px; background: var(--rule); border: 1px solid var(--rule); }
.grid2 > div { background: var(--bg); padding: 20px; }

.cta { margin: 28px 0 0; }
.button {
  display: inline-block; background: var(--accent); color: #0E1013;
  padding: 0 34px; height: 58px;
  font: 700 14px/58px var(--sans); letter-spacing: .12em;
  text-transform: uppercase; text-decoration: none;
}
.button:hover { filter: brightness(1.07); }
li b { color: var(--ink); font-weight: 600; }

.updated { font: 400 13px var(--mono); color: var(--ink-3); margin: -12px 0 34px; }

footer {
  border-top: 1px solid var(--rule); margin-top: 80px; padding-top: 24px;
  font: 400 13px var(--sans); color: var(--ink-3);
  display: flex; flex-wrap: wrap; gap: 20px; align-items: baseline;
}
footer .mail { margin-left: auto; font-family: var(--mono); }

@media (max-width: 720px) {
  :root { --gutter: 52px; --pad: 18px; }
  .rule .brand { height: 64px; }
  .rule .brand img { width: 34px; height: 34px; }
  .rule .ticks { top: 64px; }
  .rule .vertical { display: none; }
  .rule .ticks { width: 24px; }
  section > .dim { font-size: 9px; }
  main { padding: 22px var(--pad) 100px; }
}