/* Free as in Bird — site styles.
   Plain static CSS. Dark mode is driven entirely by prefers-color-scheme
   (no JavaScript). The [data-theme] overrides let a manual choice win if
   one is ever set, but nothing on the public site sets it. */

/* ---------- Fonts (self-hosted, Latin subset, swap) ---------- */
@font-face {
  font-family: "IBM Plex Serif";
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  src: url("/fonts/ibm-plex-serif-latin-400-normal.woff2") format("woff2");
}
@font-face {
  font-family: "IBM Plex Serif";
  font-style: normal;
  font-weight: 500;
  font-display: swap;
  src: url("/fonts/ibm-plex-serif-latin-500-normal.woff2") format("woff2");
}
@font-face {
  font-family: "IBM Plex Sans";
  font-style: normal;
  font-weight: 600;
  font-display: swap;
  src: url("/fonts/ibm-plex-sans-latin-600-normal.woff2") format("woff2");
}
@font-face {
  font-family: "IBM Plex Mono";
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  src: url("/fonts/ibm-plex-mono-latin-400-normal.woff2") format("woff2");
}
@font-face {
  font-family: "IBM Plex Mono";
  font-style: normal;
  font-weight: 500;
  font-display: swap;
  src: url("/fonts/ibm-plex-mono-latin-500-normal.woff2") format("woff2");
}

/* ---------- Design tokens ---------- */
:root {
  --bg: #f1efe9;
  --ink: #1b1a17;
  --ink-2: #57544e;
  --ink-3: #8c887f;
  --line: #e4e1d8;
  --brand: #d9312f;
  --sans: "IBM Plex Sans", system-ui, -apple-system, "Segoe UI", sans-serif;
  --serif: "IBM Plex Serif", Georgia, "Times New Roman", serif;
  --mono: "IBM Plex Mono", ui-monospace, "SF Mono", Menlo, monospace;
  --container: 760px;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #14130f;
    --ink: #eceae3;
    --ink-2: #9a968c;
    --ink-3: #6b6860;
    --line: #26241e;
    --brand: #ef4a41;
  }
}
:root[data-theme="dark"] {
  --bg: #14130f;
  --ink: #eceae3;
  --ink-2: #9a968c;
  --ink-3: #6b6860;
  --line: #26241e;
  --brand: #ef4a41;
}

/* ---------- Base ---------- */
* {
  box-sizing: border-box;
}
html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  /* Always reserve the scrollbar gutter so centered content doesn't shift
     between a scrolling page (about) and a non-scrolling one (landing). */
  scrollbar-gutter: stable;
}
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
::selection {
  background: var(--brand);
  color: #fff;
}
:focus-visible {
  outline: 2px solid var(--brand);
  outline-offset: 3px;
  border-radius: 2px;
}

.page {
  min-height: 100svh;
  display: flex;
  flex-direction: column;
}
.container {
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: 32px;
}

/* ---------- Header ---------- */
.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 4px 16px;
  flex-wrap: wrap;
  padding-block: 18px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 13px;
  text-decoration: none;
}
.brand__mark {
  display: block;
  flex: 0 0 auto;
}
.brand__name {
  font-weight: 600;
  font-size: 17.5px;
  letter-spacing: -0.012em;
  color: var(--ink);
  white-space: nowrap;
}
.nav {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-right: -10px;
}
.nav a {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 10px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--ink-2);
  text-decoration: none;
  transition: color 0.15s;
}
.nav a:hover {
  color: var(--ink);
}

/* ---------- Seal mark ---------- */
.seal {
  display: block;
}

/* ---------- Hero (landing) ---------- */
.hero .container {
  padding-block: 112px 96px;
}
.eyebrow {
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--ink-3);
  margin: 0;
}
.hero h1 {
  font-family: var(--serif);
  font-weight: 500;
  font-size: clamp(40px, 6.6vw, 68px);
  line-height: 1.03;
  letter-spacing: -0.02em;
  color: var(--ink);
  margin: 22px 0 0;
}
.hero__lead {
  font-family: var(--serif);
  font-weight: 400;
  font-size: clamp(19px, 2.3vw, 22px);
  line-height: 1.52;
  color: var(--ink);
  max-width: 48ch;
  margin: 38px 0 0;
}
.hero .seal {
  margin-top: 58px;
}

/* ---------- About ---------- */
.about-opening .container {
  padding-block: 76px 0;
}
.about-section .container {
  padding-block: 36px 0;
}
.prose {
  max-width: 60ch;
}

.about-title {
  font-family: var(--serif);
  font-weight: 500;
  font-size: clamp(32px, 5vw, 48px);
  line-height: 1.08;
  letter-spacing: -0.02em;
  color: var(--ink);
  margin: 20px 0 0;
}
.section-title {
  font-family: var(--serif);
  font-weight: 500;
  font-size: clamp(23px, 3.2vw, 30px);
  line-height: 1.1;
  letter-spacing: -0.015em;
  color: var(--ink);
  margin: 0 0 22px;
}

/* Serif body paragraphs. Default rhythm is 20px between paragraphs. */
.lead {
  font-family: var(--serif);
  font-weight: 400;
  font-size: clamp(18px, 2.2vw, 20px);
  line-height: 1.55;
  color: var(--ink);
  margin: 0;
}
.p {
  font-family: var(--serif);
  font-weight: 400;
  font-size: 18px;
  line-height: 1.62;
  color: var(--ink-2);
  margin: 20px 0 0;
}
.p--ink {
  color: var(--ink);
}
.p--flush {
  margin-top: 0;
}
.p--gap {
  margin-top: 24px;
}

.license-name {
  font-weight: 500;
  color: var(--ink);
}
.license-code {
  font-family: var(--mono);
  font-size: 0.8em;
  font-weight: 500;
  letter-spacing: 0.04em;
  color: var(--brand);
}

.about-ai .seal {
  margin: 48px 0 60px;
}

/* ---------- Footer ---------- */
.site-footer {
  margin-top: auto;
}
.site-footer .container {
  display: flex;
  flex-wrap: wrap;
  gap: 18px 40px;
  align-items: baseline;
  justify-content: space-between;
  padding-block: 34px 44px;
  border-top: 1px solid var(--line);
}
.footer-link {
  font-family: var(--mono);
  font-size: 13.5px;
  letter-spacing: 0.01em;
  color: var(--ink);
  text-decoration: none;
  border-bottom: 1px solid var(--ink-3);
  padding-bottom: 2px;
  white-space: nowrap;
  transition:
    border-color 0.15s,
    color 0.15s;
}
.footer-link:hover {
  border-color: var(--brand);
  color: var(--brand);
}
.copyright {
  font-family: var(--mono);
  font-size: 11.5px;
  color: var(--ink-3);
  letter-spacing: 0.02em;
  white-space: nowrap;
}

/* ---------- Motion ---------- */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  * {
    transition: none !important;
  }
}