/* ------------------------------------------------------------------ */
/*  Plaquette — minimal static stylesheet                             */
/* ------------------------------------------------------------------ */

:root {
  --fg:       #1a1a2e;
  --fg-muted: #555;
  --bg:       #ffffff;
  --bg-alt:   #f4f6f8;
  --accent:   #0b3d91;
  --accent-l: #1a5fbf;
  --border:   #d8dde2;
  --code-bg:  #eef1f4;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
               "Helvetica Neue", Arial, sans-serif;
  color: var(--fg);
  background: var(--bg);
  line-height: 1.6;
  font-size: 17px;
}

.container {
  max-width: 880px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* ---- Header ------------------------------------------------------- */

header {
  border-bottom: 1px solid var(--border);
  padding: 2.5rem 0 1.5rem;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.header-text {
  flex: 1;
}

.header-logo {
  width: 242px;
  height: auto;
}

.logo {
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--accent);
}

.tagline {
  color: var(--fg-muted);
  font-size: 1.1rem;
  margin-top: .25rem;
}

/* ---- Hero --------------------------------------------------------- */

.hero {
  padding: 1rem 0 3rem;
}

.lead {
  font-size: 1.2rem;
  max-width: 700px;
}

.lead a {
  color: var(--accent-l);
  text-decoration: none;
  border-bottom: 1px solid var(--border);
}

.lead a:hover { border-bottom-color: var(--accent-l); }

/* ---- Table of contents -------------------------------------------- */

.toc {
  margin-top: 0;
  margin-bottom: 1.5rem;
  padding: .75rem 1rem;
  border-left: 3px solid var(--accent);
  background: var(--bg-alt);
  border-radius: 0 4px 4px 0;
}

.toc ul {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
}

.toc a {
  color: var(--accent);
  text-decoration: none;
  font-size: .95rem;
  font-weight: 500;
}

.toc a:hover { text-decoration: underline; }

code {
  background: var(--code-bg);
  border-radius: 3px;
  padding: 0 .25em;
  font-size: .9em;
}

/* ---- Sections ----------------------------------------------------- */

.section     { padding: 2.5rem 0; }
.section-alt { background: var(--bg-alt); }

.section h2 {
  font-size: 1.5rem;
  margin-bottom: 1rem;
}

.section-intro {
  color: var(--fg-muted);
  margin-bottom: 2rem;
}

/* ---- Repo cards --------------------------------------------------- */

.repo-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1.5rem;
}

.notebook-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

.repo-card {
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1.5rem;
  background: var(--bg);
  transition: box-shadow .15s, border-color .15s;
}

.repo-card:hover {
  border-color: var(--accent-l);
  box-shadow: 0 2px 12px rgba(0,0,0,.07);
}

.repo-card h3 {
  font-size: 1.15rem;
  margin-bottom: .5rem;
}

.repo-card h3 a {
  color: var(--accent);
  text-decoration: none;
}

.repo-card h3 a:hover { text-decoration: underline; }

.repo-card p {
  color: var(--fg-muted);
  font-size: .95rem;
  margin-bottom: 1rem;
}

.repo-link {
  font-size: .85rem;
  color: var(--accent-l);
  text-decoration: none;
  font-family: monospace;
}

.repo-link:hover { text-decoration: underline; }

/* ---- References --------------------------------------------------- */

.references {
  list-style: none;
  counter-reset: ref;
}

.references li {
  counter-increment: ref;
  margin-bottom: 2rem;
  padding-left: 2.5rem;
  position: relative;
}

.references li::before {
  content: "[" counter(ref) "]";
  position: absolute;
  left: 0;
  font-weight: 600;
  color: var(--accent);
}

.ref-authors { font-weight: 600; }

.ref-title a {
  color: var(--accent-l);
  text-decoration: none;
}

.ref-title a:hover { text-decoration: underline; }

.ref-journal { color: var(--fg-muted); }

.ref-id {
  display: inline-block;
  margin-left: .5rem;
  font-family: monospace;
  font-size: .85rem;
}

.ref-summary {
  margin-top: .5rem;
  font-size: .9rem;
  color: var(--fg-muted);
  font-style: italic;
}

/* ---- Footer ------------------------------------------------------- */

footer {
  border-top: 1px solid var(--border);
  padding: 2rem 0;
  text-align: center;
  color: var(--fg-muted);
  font-size: .85rem;
}

footer p { margin-bottom: .5rem; }

.license {
  font-size: .8rem;
  line-height: 1.5;
}

.license a {
  color: var(--accent-l);
  text-decoration: none;
}

.license a:hover { text-decoration: underline; }

/* ---- Responsive --------------------------------------------------- */

@media (max-width: 600px) {
  .lead      { font-size: 1.05rem; }
  .repo-grid    { grid-template-columns: 1fr; }
  .notebook-grid { grid-template-columns: 1fr; }
  .header-inner { flex-direction: column; gap: 0.75rem; }
  .header-logo { width: 180px; }
  .toc ul { gap: 1rem; }
}