/* LUMEN base. Document register. */

@font-face {
  font-family: "IBM Plex Sans";
  font-weight: 300 700;
  font-style: normal;
  font-display: swap;
  /* Self-host target. For v1 prototype we declare the face; the engineering team
     drops the WOFF2 files into /assets/fonts/. The page degrades gracefully to
     system-ui if the file is absent. */
  src: local("IBM Plex Sans"), url("/assets/fonts/IBMPlexSans-var.woff2") format("woff2-variations");
}
@font-face {
  font-family: "IBM Plex Sans Arabic";
  font-weight: 300 700;
  src: local("IBM Plex Sans Arabic"), url("/assets/fonts/IBMPlexSansArabic-var.woff2") format("woff2-variations");
  font-display: swap;
}
@font-face {
  font-family: "IBM Plex Serif";
  font-weight: 300 700;
  src: local("IBM Plex Serif"), url("/assets/fonts/IBMPlexSerif-var.woff2") format("woff2-variations");
  font-display: swap;
}
@font-face {
  font-family: "IBM Plex Mono";
  font-weight: 400 600;
  src: local("IBM Plex Mono"), url("/assets/fonts/IBMPlexMono-var.woff2") format("woff2-variations");
  font-display: swap;
}

*, *::before, *::after { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }

html {
  background: var(--paper);
  color: var(--ink-900);
  font-family: var(--font-sans);
  font-size: var(--t-body);
  line-height: 1.55;
  font-feature-settings: "ss01", "ss02", "kern", "liga";
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  min-height: 100vh;
}

::selection { background: var(--ink-900); color: var(--paper); }

a { color: inherit; text-decoration: none; }
a.link {
  border-bottom: 1px solid currentColor;
  padding-bottom: 1px;
  transition: opacity var(--t-fast) var(--ease-out);
}
a.link:hover { opacity: 0.6; }

button { font: inherit; color: inherit; background: transparent; border: 0; cursor: pointer; padding: 0; }

img, svg, video { display: block; max-width: 100%; }

/* Type primitives */
.eyebrow {
  font-family: var(--font-mono);
  font-size: var(--t-eyebrow);
  letter-spacing: var(--track-eyebrow);
  text-transform: uppercase;
  color: var(--ink-500);
  font-weight: 500;
}
.display {
  font-size: var(--t-display);
  font-weight: 300;
  line-height: 0.96;
  letter-spacing: var(--track-tight);
}
.h1 { font-size: var(--t-h1); font-weight: 350; line-height: 1.02; letter-spacing: var(--track-tight); }
.h2 { font-size: var(--t-h2); font-weight: 350; line-height: 1.06; letter-spacing: var(--track-snug); }
.h3 { font-size: var(--t-h3); font-weight: 500; line-height: 1.18; letter-spacing: var(--track-snug); }
.lead { font-size: var(--t-lead); line-height: 1.45; color: var(--ink-700); font-weight: 350; }
.body { font-size: var(--t-body); color: var(--ink-700); }
.serif { font-family: var(--font-serif); font-weight: 400; }
.mono { font-family: var(--font-mono); font-feature-settings: "zero", "ss01"; letter-spacing: var(--track-mono); }
.muted { color: var(--ink-500); }

/* Hairlines */
.hair-top { border-top: var(--hair); }
.hair-bot { border-bottom: var(--hair); }

/* Layout */
.shell { max-width: var(--max-w); margin: 0 auto; padding-inline: var(--gutter); }
.section { padding-block: var(--section-y); }
.grid12 { display: grid; grid-template-columns: repeat(12, 1fr); gap: var(--gutter); }

/* Buttons. Quiet, sovereign. */
.btn {
  display: inline-flex; align-items: center; gap: 10px;
  padding: 14px 22px;
  border: 1px solid var(--ink-900);
  background: var(--ink-900);
  color: var(--paper);
  font-size: 15px; font-weight: 500;
  letter-spacing: var(--track-snug);
  transition: background var(--t-fast) var(--ease-out), color var(--t-fast) var(--ease-out);
  border-radius: 0;
}
.btn:hover { background: transparent; color: var(--ink-900); }
.btn--ghost { background: transparent; color: var(--ink-900); }
.btn--ghost:hover { background: var(--ink-900); color: var(--paper); }

/* Focus */
:focus-visible {
  outline: 2px solid var(--dawn-500);
  outline-offset: 3px;
}

/* Hairline rules used as section dividers, embassy-style */
.rule { height: 1px; background: var(--ink-200); width: 100%; }
.rule--ink { background: var(--ink-900); }

/* Specialty glyph base */
.glyph { stroke: currentColor; fill: none; stroke-width: 1; }

/* Numerals: tabular for data, lining for prose */
.num { font-variant-numeric: tabular-nums lining-nums; }

/* RTL helpers */
[dir="rtl"] .flip-on-rtl { transform: scaleX(-1); }