/* TrajFS site, in the style of jingliu.xyz: paper and ink, serif headings, an ink-wash hero.
   Plain CSS, no build step. Light only, like the homepage. */

:root {
  color-scheme: light;
  --paper: #ebeaf0;
  --paper-light: #f7f6fa;
  --ink: #191b25;
  --ink-soft: #565b6b;
  --ink-faint: rgba(45, 49, 76, 0.11);
  --mineral: #4e638f;
  --mineral-light: #8792b0;
  --cinnabar: #9f4638;
  --logo-blue: #1f6fe5;               /* the wordmark blue of the logo */
  --line: rgba(57, 61, 91, 0.16);
  --page-width: 1240px;
  --text-width: 900px;
  --code-bg: #1d2030;
  --code-ink: #e6e4ee;
  --code-dim: #8d90a6;
  --serif: "Iowan Old Style", Baskerville, "Songti SC", STSong, Georgia, serif;
  --sans: Optima, Candara, Calibri, Arial, sans-serif;
  --mono: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 5rem; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background-color: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.55;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
body::before {
  position: fixed;
  z-index: -1;
  inset: 0;
  background-image:
    repeating-linear-gradient(0deg, rgba(62, 66, 98, 0.014) 0 1px, transparent 1px 4px),
    repeating-linear-gradient(90deg, rgba(62, 66, 98, 0.01) 0 1px, transparent 1px 7px);
  content: "";
  pointer-events: none;
}
::selection { background: rgba(78, 99, 143, 0.18); }
img { max-width: 100%; height: auto; display: block; }
a {
  color: var(--mineral);
  text-decoration-color: rgba(49, 95, 99, 0.42);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.18em;
}
a:hover { color: var(--cinnabar); text-decoration-color: currentColor; }
h1, h2, h3 { font-family: var(--serif); font-weight: 400; letter-spacing: 0; margin: 0; }
h2 { font-size: 2.15rem; line-height: 1.2; }
h3 { font-size: 1.35rem; line-height: 1.25; }
p { margin: 0 0 1.05rem; }
.muted { color: var(--ink-soft); }
.small { font-size: 0.9rem; }
code {
  font-family: var(--mono);
  font-size: 0.88em;
  background: rgba(57, 61, 91, 0.07);
  padding: 0.08em 0.32em;
}
pre {
  margin: 0;
  background: var(--code-bg);
  color: var(--code-ink);
  padding: 1rem 1.15rem;
  overflow-x: auto;
  font-family: var(--mono);
  font-size: 0.83rem;
  line-height: 1.55;
  border-left: 3px solid var(--mineral);
}
pre code { background: none; padding: 0; font-size: inherit; color: inherit; }
pre .c { color: var(--code-dim); }
.wrap { width: min(calc(100% - 4rem), var(--page-width)); margin: 0 auto; }
@media (max-width: 640px) { .wrap { width: calc(100% - 2rem); } }

/* nav, as on the homepage: uppercase, letterspaced, a seal in a cinnabar square */
.site-nav {
  position: absolute;
  top: 0; right: 0; left: 0;
  z-index: 20;
}
.nav-inner {
  display: flex;
  width: min(calc(100% - 4rem), var(--page-width));
  min-height: 76px;
  align-items: center;
  justify-content: space-between;
  margin: 0 auto;
  gap: 1rem;
}
.wordmark {
  display: inline-flex; align-items: center; gap: 0.75rem;
  color: var(--ink); font-size: 0.78rem; font-weight: 650; letter-spacing: 0.14em;
  text-decoration: none; text-transform: uppercase;
}
.nav-seal {
  display: grid; width: 2rem; height: 2rem; place-items: center;
  border: 1px solid var(--cinnabar); color: var(--cinnabar);
  font-family: "Songti SC", STSong, serif; font-size: 1.05rem; font-weight: 400; letter-spacing: 0;
}
.nav-links { display: flex; align-items: center; gap: 2rem; }
.nav-links a {
  color: var(--ink); font-size: 0.77rem; font-weight: 600; letter-spacing: 0.08em;
  text-decoration: none; text-transform: uppercase;
}
.nav-links a:hover { color: var(--cinnabar); }
@media (max-width: 900px) { .nav-links { gap: 1.25rem; } .nav-links a.opt { display: none; } }
@media (max-width: 640px) { .nav-inner { width: calc(100% - 2rem); } }

/* hero: the homepage's ink-wash canvas, kicker, big serif title */
.hero {
  position: relative;
  display: grid;
  min-height: min(54.6667svh, 546.667px);
  overflow: hidden;
  border-bottom: 1px solid var(--line);
  background: var(--paper-light);
  cursor: crosshair;
  isolation: isolate;
}
.hero-canvas, .hero-grid-canvas, .hero-grain { position: absolute; inset: 0; width: 100%; height: 100%; }
.hero-canvas { z-index: -3; pointer-events: none; }
.hero-grid-canvas { z-index: -4; pointer-events: none; }
.hero-grain {
  z-index: -2;
  background-image:
    repeating-linear-gradient(7deg, rgba(55, 59, 91, 0.018) 0 1px, transparent 1px 5px),
    linear-gradient(to bottom, transparent 56%, var(--paper-light) 100%);
  mix-blend-mode: multiply;
  opacity: 0.45;
  pointer-events: none;
}
.hero-inner {
  display: flex;
  width: min(calc(100% - 4rem), var(--page-width));
  min-height: inherit;
  align-items: end;
  margin: 0 auto;
  padding: 8.5rem 0 4.5rem;
}
.hero-copy { position: relative; z-index: 2; max-width: 900px; }
.hero-kicker {
  margin: 0 0 1.2rem; color: var(--cinnabar);
  font-size: 0.74rem; font-weight: 650; letter-spacing: 0.18em; text-transform: uppercase;
}
.hero-title-row { display: flex; align-items: center; gap: 2.25rem; }
.hero h1 { margin: 0; color: var(--logo-blue); font-size: 7.25rem; font-weight: 400; line-height: 0.86; }
.hero-mark { width: 11rem; height: auto; opacity: 0.9; }
.hero-tagline {
  margin: 1.6rem 0 0.5rem; font-family: var(--serif); font-size: 1.55rem; line-height: 1.3; color: var(--ink);
}
.hero-lead { max-width: 62ch; color: var(--ink-soft); font-size: 1.02rem; margin: 0.4rem 0 1.4rem; }
.cta { display: flex; flex-wrap: wrap; gap: 0.75rem; }
.btn {
  display: inline-flex; align-items: center; gap: 0.5rem;
  padding: 0.7rem 1.1rem; border: 1px solid var(--ink); color: var(--ink);
  font-size: 0.78rem; font-weight: 650; letter-spacing: 0.1em; text-transform: uppercase; text-decoration: none;
  background: transparent;
  transition: border-color 180ms ease, color 180ms ease, background 180ms ease;
}
.btn:hover { border-color: var(--cinnabar); color: var(--cinnabar); text-decoration: none; }
.btn.primary { background: var(--ink); color: var(--paper-light); }
.btn.primary:hover { background: var(--cinnabar); border-color: var(--cinnabar); color: var(--paper-light); }
.hero-scroll {
  position: absolute; right: max(2rem, calc((100% - var(--page-width)) / 2)); bottom: 1.7rem;
  display: grid; width: 2.7rem; height: 2.7rem; place-items: center;
  border: 1px solid var(--line); color: var(--ink); font-size: 1rem; text-decoration: none;
  transition: border-color 180ms ease, color 180ms ease, transform 180ms ease;
}
.hero-scroll:hover { border-color: var(--cinnabar); color: var(--cinnabar); transform: translateY(3px); }
@media (max-width: 900px) {
  .hero h1 { font-size: 5.4rem; }
  .hero-mark { width: 8rem; }
}
@media (max-width: 640px) {
  .hero { min-height: min(57.3333svh, 506.667px); }
  .hero-inner { width: calc(100% - 2rem); padding: 6.5rem 0 4rem; }
  .hero-title-row { align-items: flex-end; gap: 1rem; }
  .hero h1 { font-size: 4.35rem; }
  .hero-mark { width: 5.3rem; margin-bottom: 0.2rem; }
  .hero-tagline { font-size: 1.25rem; }
  .hero-scroll { right: 1.125rem; bottom: 1.125rem; }
}

/* sections: serif headings ruled like the homepage's */
section.block, .pillars, .demo { padding: 3.5rem 0 0.5rem; }
.section-head { max-width: var(--text-width); margin-bottom: 1.6rem; }
.section-head h2 {
  margin: 0 0 1.2rem; padding-bottom: 0.7rem; border-bottom: 1px solid var(--line);
}
.section-head p { color: var(--ink-soft); font-size: 1.02rem; }
.kicker {
  margin: 0 0 0.6rem; color: var(--cinnabar);
  font-size: 0.74rem; font-weight: 650; letter-spacing: 0.18em; text-transform: uppercase;
}

/* demo */
.demo .frame { background: #0d1117; padding: 8px; border: 1px solid var(--line); max-width: 940px; margin: 0 auto; }
.demo .frame img { width: 100%; }
.demo .cap { text-align: center; margin-top: 0.8rem; }

/* pillars */
.grid3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1rem; }
@media (max-width: 820px) { .grid3 { grid-template-columns: 1fr; } }
.card { background: var(--paper-light); border: 1px solid var(--line); padding: 1.3rem 1.3rem 1rem; }
.card h3 { margin-bottom: 0.5rem; }
.card .eyebrow {
  font-size: 0.72rem; letter-spacing: 0.16em; text-transform: uppercase; color: var(--cinnabar); font-weight: 650; margin-bottom: 0.6rem;
}
.card p { color: var(--ink-soft); margin: 0; font-size: 0.97rem; }
.figure { margin: 1.8rem auto 0; max-width: 940px; }

/* steps */
.steps { display: grid; gap: 1.2rem; }
.step { display: grid; grid-template-columns: 56px 1fr; gap: 0.9rem; align-items: start; }
.step .n {
  width: 44px; height: 44px; display: grid; place-items: center;
  border: 1px solid var(--cinnabar); color: var(--cinnabar); font-family: var(--serif); font-size: 1.35rem;
}
.step h3 { margin-bottom: 0.4rem; }
.step p { color: var(--ink-soft); font-size: 0.98rem; }
.step pre { margin-top: 0.6rem; }
@media (max-width: 560px) { .step { grid-template-columns: 1fr; } .step .n { width: 36px; height: 36px; font-size: 1.1rem; } }
.two { display: grid; grid-template-columns: 1fr 1fr; gap: 1.2rem; margin-top: 1.8rem; }
@media (max-width: 820px) { .two { grid-template-columns: 1fr; } }
.two .card pre { margin-top: 0.6rem; }

/* how it works */
.points { display: grid; grid-template-columns: repeat(3, 1fr); gap: 0.9rem; counter-reset: pt; }
@media (max-width: 820px) { .points { grid-template-columns: 1fr; } }
.point { background: var(--paper-light); border: 1px solid var(--line); padding: 1.15rem 1.15rem 0.9rem; }
.point::before {
  counter-increment: pt; content: counter(pt);
  display: inline-grid; place-items: center; width: 1.7rem; height: 1.7rem;
  border: 1px solid var(--cinnabar); color: var(--cinnabar); font-family: var(--serif); font-size: 0.95rem; margin-bottom: 0.6rem;
}
.point h3 { font-size: 1.15rem; margin-bottom: 0.4rem; }
.point p { color: var(--ink-soft); font-size: 0.93rem; margin: 0; }
.layout { display: grid; grid-template-columns: 1fr 1fr; gap: 1.2rem; margin-top: 1.6rem; align-items: start; }
@media (max-width: 820px) { .layout { grid-template-columns: 1fr; } }
.layout table { width: 100%; border-collapse: collapse; font-size: 0.93rem; }
.layout th, .layout td { text-align: left; padding: 0.5rem 0.6rem; border-bottom: 1px solid var(--line); vertical-align: top; }
.layout th { color: var(--ink-soft); font-weight: 600; font-size: 0.74rem; text-transform: uppercase; letter-spacing: 0.1em; }

/* benchmarks */
.bench { display: grid; gap: 1.8rem; }
.bench figure { margin: 0; background: #fff; border: 1px solid var(--line); padding: 0.9rem; }
.bench figcaption { padding: 0.8rem 0.3rem 0.1rem; color: var(--ink-soft); font-size: 0.97rem; }
.bench figcaption strong { color: var(--ink); font-weight: 650; }
.stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 0.8rem; margin: 0.4rem 0 1.6rem; }
@media (max-width: 820px) { .stats { grid-template-columns: repeat(2, 1fr); } }
.stat { background: var(--paper-light); border: 1px solid var(--line); padding: 0.9rem 1rem; }
.stat .v { font-family: var(--serif); font-size: 2.3rem; line-height: 1.05; color: var(--mineral); }
.stat .l { color: var(--ink); font-size: 0.92rem; margin-top: 0.25rem; }
.stat .s { color: var(--ink-soft); font-size: 0.8rem; }
.note { border-left: 3px solid var(--cinnabar); background: var(--paper-light); padding: 0.8rem 1rem; color: var(--ink-soft); font-size: 0.97rem; }

/* install */
.install .two { margin-top: 0; }
.prompt {
  background: var(--paper-light); border: 1px dashed var(--line); padding: 0.9rem 1rem;
  font-size: 0.86rem; color: var(--ink-soft); white-space: pre-wrap; font-family: var(--mono); line-height: 1.5;
}

/* docs list */
.links { display: grid; grid-template-columns: repeat(3, 1fr); gap: 0.8rem; }
@media (max-width: 820px) { .links { grid-template-columns: 1fr; } }
.links a { display: block; background: var(--paper-light); border: 1px solid var(--line); padding: 0.8rem 0.9rem; color: var(--ink); text-decoration: none; }
.links a:hover { border-color: var(--cinnabar); color: var(--cinnabar); }
.links a span { display: block; color: var(--ink-soft); font-size: 0.85rem; margin-top: 0.15rem; }

/* footer */
.site-footer { margin-top: 4rem; border-top: 1px solid var(--line); }
.footer-inner {
  display: flex; flex-wrap: wrap; gap: 0.8rem 1.5rem;
  width: min(calc(100% - 4rem), var(--page-width)); min-height: 132px;
  align-items: center; justify-content: space-between; margin: 0 auto; color: var(--ink-soft); font-size: 0.9rem;
}
.footer-inner p { margin: 0; font-family: var(--serif); color: var(--ink); }
.footer-inner p span { color: var(--cinnabar); margin-right: 0.4rem; }