/* CUELO public page. Mirrors the app's rule: neutral ink carries the page,
   colour is reserved for meaning (links, focus). System fonts only, so the
   page makes no third-party requests. */
:root {
  color-scheme: light dark;
  --paper: #f6f7f9;
  --panel: #ffffff;
  --ink: #15171b;
  --muted: #545b67;
  --rule: #d8dce2;
  --rule-strong: #aab1bc;
  --link: #1a5bb8;
  --code-bg: #eceef2;
  --font-sans: system-ui, -apple-system, "Segoe UI", "Apple SD Gothic Neo", "Malgun Gothic", "Noto Sans KR", sans-serif;
  --font-mono: ui-monospace, "SF Mono", "JetBrains Mono", "Cascadia Code", "Noto Sans Mono", Consolas, "Liberation Mono", monospace;
  --measure: 40rem;
  --wide: 72rem;
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper: #111317;
    --panel: #171a1f;
    --ink: #e7e9ed;
    --muted: #9ba2ae;
    --rule: #2b3038;
    --rule-strong: #4a515c;
    --link: #82b6ff;
    --code-bg: #1d2127;
  }
}

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

html { -webkit-text-size-adjust: 100%; scroll-padding-top: 1rem; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font: 1rem/1.65 var(--font-sans);
  overflow-wrap: break-word;
}

:lang(ko) { word-break: keep-all; }

img { display: block; max-width: 100%; height: auto; }

a { color: var(--link); text-underline-offset: 0.18em; text-decoration-thickness: 1px; }
a:hover { text-decoration-thickness: 2px; }

:focus-visible {
  outline: 2px solid var(--link);
  outline-offset: 3px;
  border-radius: 2px;
}

code, pre { font-family: var(--font-mono); font-size: 0.9em; }
:not(pre) > code {
  background: var(--code-bg);
  padding: 0.08em 0.35em;
  border-radius: 4px;
  word-break: break-word;
}

.skip {
  position: absolute;
  left: 1rem;
  top: -4rem;
  padding: 0.6rem 1rem;
  background: var(--ink);
  color: var(--paper);
  z-index: 10;
}
.skip:focus { top: 1rem; }

.wrap { max-width: var(--wide); margin: 0 auto; padding: 0 1.25rem; }

/* Header */
.site-head { border-bottom: 1px solid var(--rule); }
.site-head .wrap {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem 1.5rem;
  min-height: 3.5rem;
  padding-block: 0.5rem;
}
.brand {
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--ink);
  text-decoration: none;
}
.site-nav ul {
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem 1.25rem;
  margin: 0;
  padding: 0;
  list-style: none;
}
.site-nav a {
  display: inline-flex;
  align-items: center;
  min-height: 2.75rem;
  color: var(--muted);
  text-decoration: none;
}
.site-nav a:hover { color: var(--ink); text-decoration: underline; }

/* Hero */
.hero { padding: 3.5rem 0 2.5rem; }
.hero h1 { margin: 0; font-weight: 700; line-height: 1.1; }
.hero .word {
  display: block;
  font-size: clamp(3rem, 9vw, 5.5rem);
  letter-spacing: 0.06em;
}
.hero .what {
  display: block;
  margin-top: 0.75rem;
  max-width: 30ch;
  font-size: clamp(1.35rem, 3vw, 1.9rem);
  font-weight: 600;
  letter-spacing: -0.01em;
  line-height: 1.25;
}
.lede { max-width: var(--measure); margin: 1.25rem 0 0; font-size: 1.075rem; color: var(--muted); }
.lede strong { color: var(--ink); font-weight: 600; }

.actions { display: flex; flex-wrap: wrap; gap: 0.75rem; margin-top: 1.75rem; }
.btn {
  display: inline-flex;
  align-items: center;
  min-height: 2.75rem;
  padding: 0 1.1rem;
  border: 1px solid var(--rule-strong);
  border-radius: 6px;
  color: var(--ink);
  font-weight: 600;
  text-decoration: none;
}
.btn:hover { border-color: var(--ink); text-decoration: none; }
.btn.primary { background: var(--ink); border-color: var(--ink); color: var(--paper); }
.btn.primary:hover { opacity: 0.88; }

.status { margin: 1rem 0 0; font-size: 0.925rem; color: var(--muted); }

.hero-figure { margin: 2.5rem 0 0; }
.hero-figure img { width: 100%; border-radius: 8px; background: #11101f; aspect-ratio: 1600 / 686; }
.hero-figure figcaption { margin-top: 0.6rem; font-size: 0.875rem; color: var(--muted); }

/* Sections */
section { padding: 3rem 0; border-top: 1px solid var(--rule); }
section h2 {
  margin: 0 0 1rem;
  font-size: clamp(1.4rem, 2.6vw, 1.75rem);
  line-height: 1.25;
  letter-spacing: -0.01em;
}
section > .wrap > p, .prose p { max-width: var(--measure); }
section p { margin: 0 0 1rem; }
.note { font-size: 0.925rem; color: var(--muted); }

/* Signature: the cue loop. A real four-step sequence, so the step numbers
   carry order information. */
.loop {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  margin: 1.75rem 0 1rem;
  padding: 0;
  list-style: none;
  counter-reset: step;
  border: 1px solid var(--rule-strong);
  border-radius: 8px;
  background: var(--panel);
}
.loop li {
  position: relative;
  padding: 1.1rem 1.25rem 1.25rem;
  counter-increment: step;
}
.loop li + li { border-left: 1px solid var(--rule); }
.loop li::before {
  content: counter(step);
  display: block;
  font-size: 0.8rem;
  font-weight: 600;
  font-variant-numeric: tabular-nums;
  color: var(--muted);
}
.loop li:not(:last-child)::after {
  content: "→";
  content: "→" / "";
  position: absolute;
  right: -0.55rem;
  top: 1.2rem;
  z-index: 1;
  padding: 0 0.1rem;
  background: var(--panel);
  color: var(--muted);
  line-height: 1;
}
.loop strong { display: block; margin: 0.35rem 0 0.25rem; font-size: 1.05rem; }
.loop p { margin: 0; color: var(--muted); font-size: 0.95rem; }

/* Two parts */
.parts { display: grid; grid-template-columns: 1fr 1fr; gap: 2.5rem; margin-top: 1.5rem; }
.parts h3 { margin: 0 0 0.25rem; font-size: 1.15rem; }
.parts .where { margin: 0 0 0.75rem; font-size: 0.875rem; color: var(--muted); }
.parts ul { margin: 0 0 1rem; padding-left: 1.1rem; }
.parts li { margin-bottom: 0.35rem; }

/* Tables and code: keyboard-scrollable regions */
.scroll { overflow-x: auto; margin: 1.25rem 0; }
table { width: 100%; border-collapse: collapse; font-size: 0.95rem; }
th, td { padding: 0.75rem 0.9rem; border-bottom: 1px solid var(--rule); text-align: left; vertical-align: top; }
thead th { border-bottom-color: var(--rule-strong); font-size: 0.85rem; color: var(--muted); font-weight: 600; }
tbody th { width: 30%; font-weight: 600; }

pre {
  margin: 1.25rem 0;
  padding: 1rem 1.1rem;
  overflow-x: auto;
  background: var(--code-bg);
  border-radius: 8px;
  line-height: 1.55;
}
pre .c { color: var(--muted); }

/* Footer */
.site-foot { padding: 2.5rem 0 3rem; border-top: 1px solid var(--rule); font-size: 0.9rem; color: var(--muted); }
.site-foot p { max-width: 48rem; margin: 0 0 0.75rem; }

@media (max-width: 860px) {
  .loop { grid-template-columns: 1fr 1fr; }
  .loop li:nth-child(3) { border-left: 0; }
  .loop li:nth-child(n + 3) { border-top: 1px solid var(--rule); }
  .loop li:nth-child(2)::after { display: none; }
  .parts { grid-template-columns: 1fr; gap: 1.5rem; }
}

@media (max-width: 520px) {
  .hero { padding-top: 2.25rem; }
  /* The hero's "Run from source" button sits right below; keep the nav on one row. */
  .site-nav .nav-run { display: none; }
  .loop { grid-template-columns: 1fr; }
  .loop li + li { border-left: 0; border-top: 1px solid var(--rule); }
  .loop li:not(:last-child)::after { display: none; }
  /* Stack each row so the heading cell no longer competes with long code tokens. */
  .scroll table, .scroll tbody, .scroll tr, .scroll th, .scroll td { display: block; width: auto; }
  .scroll thead { position: absolute; width: 1px; height: 1px; overflow: hidden; clip-path: inset(50%); }
  .scroll tbody th { padding: 0.9rem 0 0.2rem; border-bottom: 0; }
  .scroll td { padding: 0 0 0.9rem; }
}

@media (prefers-reduced-motion: no-preference) {
  a, .btn { transition: color 0.15s, border-color 0.15s, opacity 0.15s, text-decoration-thickness 0.15s; }
}