/* Rulebook's site. The palette and the ruled lines come from the app icon: black ink on paper,
   and the blue of ruled writing paper. */
:root {
  --paper: #fcfbf8;
  --ink: #17181a;
  --soft: #5c6068;
  --rule: #8db9ea;
  --link: #1f5fbf;
  --hairline: #e4e2dc;
  --column: 1040px;
  --gutter: clamp(20px, 5vw, 56px);
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root {
    --paper: #141517;
    --ink: #f3f2ee;
    --soft: #a2a6ad;
    --rule: #4e7fb5;
    --link: #8db9ea;
    --hairline: #2a2c30;
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font: 17px/1.55 -apple-system, BlinkMacSystemFont, "SF Pro Text", "PingFang SC", "Helvetica Neue", "Segoe UI", sans-serif;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--link); text-underline-offset: 0.18em; }
a:focus-visible, .download:focus-visible { outline: 3px solid var(--rule); outline-offset: 3px; border-radius: 4px; }
code { font: 0.92em ui-monospace, "SF Mono", Menlo, monospace; }

.column { max-width: var(--column); margin: 0 auto; padding: 0 var(--gutter); }

/* Header */
.top { display: flex; align-items: baseline; justify-content: space-between; padding-top: 28px; padding-bottom: 28px; }
.top .name { font-weight: 700; font-size: 19px; letter-spacing: -0.01em; color: var(--ink); text-decoration: none; }
.top nav { display: flex; gap: 22px; font-size: 15px; }
.top nav a { color: var(--soft); text-decoration: none; }
.top nav a:hover { color: var(--ink); text-decoration: underline; }

/* The letter on its three rules: cap height, a dashed midline, the baseline. They run the full width of the page. */
.rules {
  --height: clamp(132px, 21vw, 232px);
  --weight: max(3px, calc(var(--height) * 0.021));
  position: relative;
  height: var(--height);
  border-top: var(--weight) solid var(--rule);
  border-bottom: var(--weight) solid var(--rule);
}
.rules::before {
  content: "";
  position: absolute;
  left: 0; right: 0; top: calc(50% - var(--weight) / 2);
  height: var(--weight);
  background: repeating-linear-gradient(90deg, var(--rule) 0 calc(var(--weight) * 4.4), transparent 0 calc(var(--weight) * 7.8));
}
.rules .column { height: 100%; position: relative; }
.rules svg { display: block; height: 100%; width: auto; fill: var(--ink); }

/* Opening */
.opening { padding-top: clamp(36px, 6vw, 64px); }
h1 {
  margin: 0;
  max-width: 17em;
  font-size: clamp(34px, 5.4vw, 60px);
  line-height: 1.06;
  font-weight: 700;
  letter-spacing: -0.028em;
  text-wrap: balance;
}
.lede { max-width: 38em; margin: 22px 0 0; font-size: clamp(18px, 2vw, 21px); line-height: 1.5; color: var(--soft); }
.get { display: flex; flex-wrap: wrap; align-items: center; gap: 14px 22px; margin-top: 30px; }
.download {
  display: inline-block;
  padding: 13px 22px;
  border-radius: 11px;
  background: var(--ink);
  color: var(--paper);
  font-weight: 600;
  text-decoration: none;
}
.download:hover { opacity: 0.86; }
.get p { margin: 0; font-size: 15px; color: var(--soft); }

/* Screenshots are window captures with transparent corners, so the shadow follows the window. */
figure { margin: clamp(40px, 7vw, 72px) 0 0; }
figure img { display: block; width: 100%; height: auto; filter: drop-shadow(0 18px 38px rgba(0, 0, 0, 0.16)) drop-shadow(0 0 1px rgba(0, 0, 0, 0.28)); }
@media (prefers-color-scheme: dark) {
  figure img { filter: drop-shadow(0 18px 38px rgba(0, 0, 0, 0.5)); }
}

section { padding-top: clamp(72px, 11vw, 128px); }
h2 { margin: 0; max-width: 20em; font-size: clamp(26px, 3.4vw, 36px); line-height: 1.14; font-weight: 700; letter-spacing: -0.02em; text-wrap: balance; }
section > p, .install p { max-width: 38em; margin: 16px 0 0; color: var(--soft); }
section > p strong { color: var(--ink); font-weight: 600; }

/* How CLAUDE.md and AGENTS.md can relate */
.states { display: grid; grid-template-columns: max-content 1fr; gap: 0 32px; max-width: 46em; margin: 30px 0 0; }
.states dt, .states dd { margin: 0; padding: 11px 0; border-top: 1px solid var(--hairline); }
.states dt { font-weight: 600; }
.states dd { color: var(--soft); }
@media (max-width: 560px) {
  .states { grid-template-columns: 1fr; }
  .states dd { border-top: 0; padding-top: 0; }
}

.install ol { max-width: 38em; margin: 16px 0 0; padding-left: 1.3em; color: var(--soft); }
.install li { margin-top: 6px; }

footer { margin-top: clamp(80px, 12vw, 136px); border-top: var(--weight, 3px) solid var(--rule); }
footer .column { display: flex; flex-wrap: wrap; gap: 8px 24px; justify-content: space-between; padding-top: 24px; padding-bottom: 44px; font-size: 15px; color: var(--soft); }
footer a { color: var(--soft); }