@import url("https://cdn.jsdelivr.net/npm/@fontsource-variable/inter@5.1.0/index.css");

/* Shared styles for the cluster algebras formalization site.
   Design tokens follow primegaps.axiommath.ai (Axiom Math): Inter for UI, Georgia for display
   headings, accent #0036a3, light blue brand gradient. Page-specific styles live in the page's
   own <style> or assets/<page>.css; keep tokens here. */

:root {
  color-scheme: light;
  --ink: #141414;
  --muted: #525252;
  --accent: #0036a3;
  --accent-ink: #ffffff;
  --brand: #99bbff;
  --brand-light: #ebf1ff;
  --brand-gradient: linear-gradient(327deg, #99bbff 0%, #e0ebff 100%);
  --paper: #ffffff;
  --card: #ffffff;
  --line: #c2d6ff;
  --panel: #f5f7fb;
  --focus: #005fcc;

  /* Formalization status colours (used on the blueprint, graph and playground pages). */
  --st-formalized: #1f7a4d;
  --st-formalized-bg: #e7f5ee;
  --st-assumed: #a35c00;
  --st-assumed-bg: #fff3e0;
  --st-excluded: #6b6b6b;
  --st-excluded-bg: #f0f0f0;

  --s1: 8px; --s2: 16px; --s3: 24px; --s4: 32px; --s5: 40px; --s6: 48px; --s7: 56px; --s8: 64px;
  --sans: "Inter Variable", Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --serif: Georgia, "Times New Roman", Times, serif;
  --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --radius: 10px;
  --maxw: 1100px;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.6;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
a:focus-visible, button:focus-visible, input:focus-visible, select:focus-visible {
  outline: 2px solid var(--focus); outline-offset: 2px;
}
code { font-family: var(--mono); font-size: 0.9em; }
h1, h2, .display { font-family: var(--serif); font-weight: 400; letter-spacing: -0.01em; }

/* ---- Site header (identical markup on every page) ----
   <header class="site-header">
     <a class="brand" href="index.html"><img class="brand-logo" src="assets/axiom-logo.svg" alt="Axiom Math"></a>
     <nav class="site-nav">
       <a href="index.html">Home</a> <a href="blueprint.html">Blueprint</a> <a href="graph.html">Dependency graph</a>
       <a href="playground.html">Playground</a> <a href="https://github.com/AxiomMath/ClusterAlgebras">GitHub</a>
     </nav>
   </header>
   Mark the current page's link with aria-current="page". */
.site-header {
  position: sticky; top: 0; z-index: 50;
  display: flex; align-items: center; justify-content: space-between; gap: var(--s2);
  padding: 12px var(--s3);
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: saturate(1.4) blur(8px);
  border-bottom: 1px solid var(--line);
}
.brand {
  display: inline-flex; align-items: center; gap: 10px;
  font-family: var(--sans); font-weight: 600; font-size: 20px; color: var(--ink);
}
.brand:hover { text-decoration: none; }
.brand-logo { display: block; height: 36px; width: auto; margin: -6px 0; }
.site-nav { display: flex; flex-wrap: wrap; gap: 4px 20px; font-weight: 600; font-size: 15px; }
.site-nav a { color: var(--ink); padding: 4px 0; border-bottom: 2px solid transparent; }
.site-nav a:hover { text-decoration: none; color: var(--accent); }
.site-nav a[aria-current="page"] { color: var(--accent); border-bottom-color: var(--accent); }

/* ---- Buttons ---- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 10px 22px; border-radius: 999px; font-weight: 600; font-size: 15px;
  border: 2px solid var(--accent); cursor: pointer; font-family: var(--sans);
}
.btn-primary { background: var(--accent); color: var(--accent-ink); }
.btn-secondary { background: var(--paper); color: var(--accent); }
.btn:hover { text-decoration: none; filter: brightness(1.08); }

/* ---- Status badges ---- */
.status { display: inline-block; font-size: 12px; font-weight: 600; padding: 2px 8px; border-radius: 999px; }
.status-formalized { color: var(--st-formalized); background: var(--st-formalized-bg); }
.status-assumed { color: var(--st-assumed); background: var(--st-assumed-bg); }
.status-excluded { color: var(--st-excluded); background: var(--st-excluded-bg); }

/* ---- Layout helpers ---- */
.container { max-width: var(--maxw); margin: 0 auto; padding: 0 var(--s3); }
.panel { background: var(--panel); border-radius: var(--radius); padding: var(--s3); }
.muted { color: var(--muted); }

.site-footer {
  margin-top: var(--s8); padding: var(--s4) var(--s3); border-top: 1px solid var(--line);
  color: var(--muted); font-size: 14px; text-align: center;
}

@media (max-width: 640px) {
  .site-header { flex-direction: column; align-items: flex-start; padding: 10px 16px; }
  .container { padding: 0 16px; }
}