/* gosum.eu — shared tokens, nav, primitives.
   Café (light) is default; [data-theme="atelier"] swaps to dark. */

:root {
  --paper: #f7f4ee;
  --surface: #ffffff;
  --surface-tint: #fffaf0;
  --ink: #2a2520;
  --mute: #8a7f73;
  --accent: #3a6b6b;
  --accent-warm: #c7986b;
  --border: #e4ddd0;
  --border-soft: #efe9dc;

  --serif: 'Fraunces','Source Serif 4',Georgia,serif;
  --mono: 'JetBrains Mono',ui-monospace,'SF Mono',monospace;

  --text-xs: 0.625rem; --text-sm: 0.8rem; --text-base: 1rem;
  --text-md: 1.25rem; --text-lg: 1.625rem; --text-xl: 2.375rem;
  --text-2xl: 3.5rem;

  --space-1: 4px;  --space-2: 8px;  --space-3: 12px; --space-4: 16px;
  --space-6: 24px; --space-8: 32px; --space-12: 48px; --space-16: 64px;
  --space-24: 96px; --space-32: 128px;

  --nav-h: 64px;
}
[data-theme="atelier"] {
  --paper: #0a0e1a;
  --surface: #11162a;
  --surface-tint: #0d1222;
  --ink: #e8e6dc;
  --mute: #8b92a8;
  --accent: #5dd9c1;
  --accent-warm: #f5b842;
  --border: #1f2940;
  --border-soft: #161c30;
}

*,*::before,*::after { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  background: var(--paper);
  color: var(--ink);
  font-family: var(--serif);
  font-size: var(--text-base);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  font-variant-numeric: tabular-nums;
  transition: background-color 240ms ease, color 240ms ease;
}
a { color: inherit; }
::selection { background: color-mix(in oklab, var(--accent) 28%, transparent); }

/* ───────────── nav ───────────── */
.nav {
  position: sticky; top: 0; z-index: 20;
  height: var(--nav-h);
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 var(--space-12);
  background: color-mix(in oklab, var(--paper) 92%, transparent);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color 200ms ease, background-color 240ms ease;
}
.nav.is-scrolled { border-bottom-color: var(--border-soft); }

.wordmark {
  font-family: var(--serif);
  font-style: italic;
  font-weight: 500;
  letter-spacing: -0.01em;
  color: var(--ink);
  text-decoration: none;
  line-height: 1;
  display: inline-flex; align-items: baseline;
}
.wordmark .stop { font-style: normal; color: var(--accent); margin-left: 1px; }
.wordmark.size-nav    { font-size: 18px; }
.wordmark.size-header { font-size: 28px; }
.wordmark.size-hero   { font-size: 56px; }

.nav-right {
  display: flex; align-items: center; gap: var(--space-6);
}
.nav-links {
  display: flex; align-items: center;
  gap: var(--space-6);
  font-family: var(--mono);
  font-size: 14px;
  font-weight: 400;
}
.nav-links a {
  color: var(--ink);
  text-decoration: none;
  opacity: 0.72;
  transition: opacity 100ms ease, color 100ms ease;
}
.nav-links a:hover, .nav-links a[aria-current="page"] { opacity: 1; color: var(--accent); }
.nav-sep { color: var(--mute); opacity: 0.5; user-select: none; }
.nav-links a[href="Paper.html"],
.nav-links a[href="Paper.html"] + .nav-sep {
  display: none;
}

/* Theme toggle — small mono pill */
.theme-toggle {
  appearance: none;
  border: 1px solid var(--border);
  background: transparent;
  color: var(--ink);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  padding: 6px 10px 6px 24px;
  cursor: default;
  position: relative;
  display: inline-flex; align-items: center; gap: 6px;
  transition: border-color 120ms ease, color 120ms ease;
}
.theme-toggle::before {
  content: "";
  position: absolute;
  left: 9px; top: 50%; transform: translateY(-50%);
  width: 10px; height: 10px; border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 0 2px color-mix(in oklab, var(--accent) 22%, transparent);
  transition: background-color 200ms ease;
}
.theme-toggle:hover { border-color: var(--ink); }
.theme-toggle .lbl-cafe    { display: inline; }
.theme-toggle .lbl-atelier { display: none; }
[data-theme="atelier"] .theme-toggle .lbl-cafe    { display: none; }
[data-theme="atelier"] .theme-toggle .lbl-atelier { display: inline; }

/* ───────────── buttons ───────────── */
.btn {
  font-family: var(--mono);
  font-size: 14px;
  letter-spacing: 0.05em;
  padding: 12px 20px;
  border: 1px solid transparent;
  cursor: default;
  text-decoration: none;
  line-height: 1;
  display: inline-flex; align-items: center; gap: var(--space-2);
  transition: background-color 100ms ease, color 100ms ease, border-color 100ms ease;
}
.btn-primary { background: var(--accent); color: var(--paper); font-weight: 500; }
.btn-primary:hover { background: color-mix(in oklab, var(--accent) 92%, black); }
.btn-secondary { background: transparent; color: var(--ink); border-color: var(--border); font-weight: 400; }
.btn-secondary:hover { border-color: var(--ink); }
.btn .arrow { font-family: var(--serif); font-style: italic; opacity: 0.85; }

/* ───────────── colophon footer ───────────── */
.colophon {
  border-top: 1px solid var(--border-soft);
  padding: var(--space-8) var(--space-12);
  display: flex; justify-content: space-between; align-items: center;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--mute);
  flex-wrap: wrap;
  gap: var(--space-3);
}
.colophon a { text-decoration: none; color: inherit; opacity: 0.75; }
.colophon a:hover { opacity: 1; color: var(--ink); }
.colophon .stop { color: var(--accent); }

/* ───────────── prose mode ───────────── */
.prose {
  max-width: 720px;
  margin: 0 auto;
  padding: var(--space-16) var(--space-6) var(--space-24);
}
.prose .eyebrow {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--mute);
  margin-bottom: var(--space-6);
}
.prose h1 {
  font-family: var(--serif); font-style: italic; font-weight: 400;
  font-size: var(--text-xl); line-height: 1.15; letter-spacing: -0.012em;
  margin: 0 0 var(--space-8); text-wrap: balance;
}
.prose h2 {
  font-family: var(--serif); font-style: italic; font-weight: 400;
  font-size: var(--text-lg); line-height: 1.2;
  margin: var(--space-12) 0 var(--space-4);
}
.prose p {
  font-size: 18px; line-height: 1.65; max-width: 64ch; text-wrap: pretty;
  margin: 0 0 var(--space-4);
}
.prose .pull {
  font-family: var(--serif); font-style: italic; font-weight: 400;
  font-size: 22px; line-height: 1.5;
  max-width: 600px; margin: var(--space-12) auto;
  text-align: center; text-wrap: balance;
}
.prose .pull-cap {
  display: block; margin-top: var(--space-3);
  font-family: var(--mono); font-style: normal; font-size: 10px;
  letter-spacing: 0.18em; text-transform: uppercase; color: var(--mute);
}
.prose hr {
  border: 0; border-top: 1px solid var(--border-soft);
  margin: var(--space-16) 0;
}

/* responsive */
@media (max-width: 880px) {
  .nav { padding: 0 var(--space-6); }
  .nav-links { gap: var(--space-4); font-size: 12px; }
  .nav-right { gap: var(--space-4); }
  .colophon { padding: var(--space-6); }
}
@media (max-width: 540px) {
  .nav-links .nav-sep, .nav-links a:nth-child(n+5) { display: none; }
  .theme-toggle { font-size: 10px; padding: 5px 9px 5px 22px; }
}