/* LPG Modeler — documentation site */

:root {
  --paper: #fcfbf9;
  --surface: #ffffff;
  --ink: #14181f;
  --ink-2: #3c4653;
  --muted: #5f6a7a;
  --line: #e3e6ec;
  --line-soft: #eef0f4;
  --accent: #2f5fe0;
  --accent-ink: #1f47b5;
  --accent-soft: #eef2fb;
  --violet: #5b3ba8;
  --violet-soft: #f4efff;
  --amber: #8a5a13;
  --amber-soft: #fdf6ec;
  --amber-line: #eccfa4;
  --green: #1d6b3a;
  --green-soft: #eaf6ee;
  --code-bg: #f6f7f9;
  --shadow: 0 1px 2px rgba(20, 24, 31, .04), 0 8px 24px rgba(20, 24, 31, .05);
  --radius: 12px;
  --measure: 68ch;
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper: #101317;
    --surface: #171b21;
    --ink: #eef1f5;
    --ink-2: #c3cbd6;
    --muted: #939eae;
    --line: #262c35;
    --line-soft: #1e242b;
    --accent: #7ba1ff;
    --accent-ink: #a8c1ff;
    --accent-soft: #182238;
    --violet: #b79bf0;
    --violet-soft: #211a33;
    --amber: #e0ad63;
    --amber-soft: #241d12;
    --amber-line: #4a3a1e;
    --green: #79cf9a;
    --green-soft: #14251a;
    --code-bg: #12161b;
    --shadow: 0 1px 2px rgba(0, 0, 0, .3), 0 8px 24px rgba(0, 0, 0, .28);
  }
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: Inter, ui-sans-serif, -apple-system, "Segoe UI", Helvetica, Arial, sans-serif;
  font-size: 16.5px;
  line-height: 1.62;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

.wrap { max-width: 1120px; margin: 0 auto; padding: 0 28px; }
.narrow { max-width: var(--measure); }

/* ---- nav ---- */
header.top {
  position: sticky; top: 0; z-index: 20;
  background: color-mix(in srgb, var(--paper) 88%, transparent);
  backdrop-filter: saturate(1.6) blur(10px);
  border-bottom: 1px solid var(--line);
}
header.top .wrap { display: flex; align-items: center; gap: 26px; height: 62px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 650; color: var(--ink); text-decoration: none; letter-spacing: -.01em; }
.brand img { width: 26px; height: 26px; border-radius: 7px; display: block; }
nav.links { display: flex; gap: 20px; margin-left: auto; flex-wrap: wrap; }
nav.links a { color: var(--muted); text-decoration: none; font-size: 14.5px; font-weight: 500; }
nav.links a:hover, nav.links a[aria-current="page"] { color: var(--accent); }

/* ---- hero ---- */
.hero { padding: 76px 0 40px; }
.eyebrow {
  display: inline-block; font-size: 12.5px; font-weight: 600; letter-spacing: .09em;
  text-transform: uppercase; color: var(--accent);
  background: var(--accent-soft); border-radius: 999px; padding: 5px 13px; margin-bottom: 22px;
}
h1 {
  font-family: "Instrument Serif", Georgia, "Times New Roman", serif;
  font-weight: 400; font-size: clamp(38px, 5.6vw, 62px); line-height: 1.06;
  letter-spacing: -.015em; margin: 0 0 20px; max-width: 17ch;
}
.lede { font-size: clamp(17px, 2vw, 20px); color: var(--ink-2); max-width: 60ch; margin: 0 0 30px; }

.cta { display: flex; gap: 12px; flex-wrap: wrap; align-items: center; }
.btn {
  display: inline-flex; align-items: center; gap: 8px; text-decoration: none;
  font-size: 15px; font-weight: 560; padding: 11px 20px; border-radius: 9px;
  border: 1px solid transparent; transition: transform .12s ease, background .12s ease;
}
.btn:active { transform: translateY(1px); }
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { background: var(--accent-ink); }
.btn-ghost { border-color: var(--line); color: var(--ink); background: var(--surface); }
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); }

/* ---- sections ---- */
section { padding: 52px 0; }
section.tight { padding: 34px 0; }
h2 {
  font-family: "Instrument Serif", Georgia, serif; font-weight: 400;
  font-size: clamp(27px, 3.4vw, 38px); line-height: 1.14; letter-spacing: -.012em;
  margin: 0 0 14px;
}
h3 { font-size: 17.5px; font-weight: 650; letter-spacing: -.008em; margin: 34px 0 8px; }
h4 { font-size: 15px; font-weight: 650; margin: 22px 0 6px; }
p { margin: 0 0 16px; max-width: var(--measure); }
.section-lede { color: var(--muted); max-width: 62ch; margin-bottom: 30px; }
.rule { height: 1px; background: var(--line); border: 0; margin: 0; }

/* ---- cards ---- */
.grid { display: grid; gap: 18px; }
.grid-2 { grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); }
.grid-3 { grid-template-columns: repeat(auto-fit, minmax(258px, 1fr)); }

.card {
  background: var(--surface); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 22px 22px 20px;
}
.card h3 { margin: 0 0 7px; font-size: 16.5px; }
.card p { margin: 0; color: var(--muted); font-size: 14.6px; max-width: none; }
.card .tag {
  display: inline-block; font-size: 11.5px; font-weight: 600; letter-spacing: .05em;
  text-transform: uppercase; color: var(--muted); margin-bottom: 10px;
}

.feature { display: grid; gap: 4px; }
.feature .k { font-weight: 650; font-size: 16px; }
.feature .v { color: var(--muted); font-size: 14.6px; }

/* ---- figures ---- */
figure { margin: 30px 0; }
figure img {
  width: 100%; height: auto; display: block;
  border: 1px solid var(--line); border-radius: var(--radius);
  background: #fcfbf9;
}
figcaption { color: var(--muted); font-size: 13.6px; margin-top: 11px; max-width: var(--measure); }

/* ---- code ---- */
code, kbd, pre, .mono {
  font-family: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}
:not(pre) > code {
  background: var(--code-bg); border: 1px solid var(--line-soft);
  border-radius: 5px; padding: 1.5px 5px; font-size: .875em; color: var(--ink);
}
pre {
  background: var(--code-bg); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 17px 19px; overflow-x: auto;
  font-size: 13.4px; line-height: 1.62; margin: 0 0 18px; color: var(--ink-2);
}
pre code { background: none; border: 0; padding: 0; font-size: inherit; color: inherit; }
.c-com { color: var(--muted); font-style: italic; }
.c-key { color: var(--accent); }
.c-str { color: var(--green); }
.c-warn { color: var(--amber); }

/* ---- tabs ---- */
.tabs { display: flex; gap: 6px; flex-wrap: wrap; margin-bottom: 14px; }
.tabs button {
  font: inherit; font-size: 13.6px; font-weight: 560; cursor: pointer;
  background: var(--surface); color: var(--muted);
  border: 1px solid var(--line); border-radius: 8px; padding: 7px 15px;
}
.tabs button[aria-selected="true"] { background: var(--accent-soft); color: var(--accent); border-color: var(--accent); }
.panel[hidden] { display: none; }

/* ---- table ---- */
.table-scroll { overflow-x: auto; margin: 0 0 20px; }
table { border-collapse: collapse; width: 100%; font-size: 14.6px; min-width: 560px; }
th, td { text-align: left; padding: 11px 14px; border-bottom: 1px solid var(--line-soft); vertical-align: top; }
th { font-size: 12.5px; letter-spacing: .05em; text-transform: uppercase; color: var(--muted); font-weight: 600; border-bottom-color: var(--line); }
td code { white-space: nowrap; }

.pill { display: inline-block; font-size: 12.4px; font-weight: 600; padding: 2.5px 10px; border-radius: 999px; white-space: nowrap; }
.pill-ok { background: var(--green-soft); color: var(--green); }
.pill-warn { background: var(--amber-soft); color: var(--amber); }
.pill-alt { background: var(--violet-soft); color: var(--violet); }
.pill-off { background: var(--code-bg); color: var(--muted); }

/* ---- callout ---- */
.note {
  background: var(--amber-soft); border: 1px solid var(--amber-line);
  border-radius: var(--radius); padding: 17px 20px; margin: 24px 0; color: var(--ink-2);
}
.note strong { color: var(--amber); }
.note p:last-child { margin-bottom: 0; }

/* ---- steps ---- */
ol.steps { counter-reset: s; list-style: none; padding: 0; margin: 26px 0; }
ol.steps > li { counter-increment: s; position: relative; padding-left: 46px; margin-bottom: 30px; }
ol.steps > li::before {
  content: counter(s); position: absolute; left: 0; top: 1px;
  width: 29px; height: 29px; border-radius: 50%;
  background: var(--accent-soft); color: var(--accent);
  font-size: 14px; font-weight: 650; display: grid; place-items: center;
}
ol.steps > li > h3 { margin-top: 0; }

ul.plain { list-style: none; padding: 0; }
ul.plain li { padding-left: 22px; position: relative; margin-bottom: 10px; color: var(--ink-2); max-width: var(--measure); }
ul.plain li::before { content: ""; position: absolute; left: 4px; top: .68em; width: 6px; height: 6px; border-radius: 50%; background: var(--accent); }

dl.args { margin: 0; }
dl.args dt { font-family: "JetBrains Mono", ui-monospace, Menlo, monospace; font-size: 14px; color: var(--accent); margin-top: 16px; }
dl.args dd { margin: 4px 0 0; color: var(--muted); font-size: 14.6px; }

/* ---- next / footer ---- */
.next { display: grid; gap: 14px; grid-template-columns: repeat(auto-fit, minmax(258px, 1fr)); margin-top: 12px; }
.next a {
  display: block; text-decoration: none; color: inherit;
  background: var(--surface); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 18px 20px;
}
.next a:hover { border-color: var(--accent); }
.next .k { font-weight: 650; font-size: 15.5px; margin-bottom: 4px; }
.next .v { color: var(--muted); font-size: 14px; }

footer.site { border-top: 1px solid var(--line); padding: 34px 0 56px; margin-top: 40px; color: var(--muted); font-size: 14px; }
footer.site .wrap { display: flex; gap: 18px; flex-wrap: wrap; align-items: center; }
footer.site a { color: var(--muted); }
footer.site .spacer { margin-left: auto; }

a { color: var(--accent); }
a:hover { color: var(--accent-ink); }

@media (max-width: 700px) {
  .wrap { padding: 0 20px; }
  .hero { padding: 48px 0 28px; }
  header.top .wrap { height: auto; padding-top: 12px; padding-bottom: 12px; flex-wrap: wrap; gap: 12px; }
  nav.links { margin-left: 0; width: 100%; gap: 15px; }
}