:root {
  --navy-0: #080b16;
  --navy-1: #0d1430;
  --navy-2: #161e3d;
  --amber-1: #ffd27a;
  --amber-2: #ff9d4d;
  --teal: #5eead4;
  --text: #eef2fb;
  --muted: #9aa6c9;
  --line: rgba(255, 255, 255, 0.08);
  --panel: rgba(255, 255, 255, 0.03);
  --display: "Chakra Petch", system-ui, sans-serif;
  --max: 1100px;

  /* Verso highlights default to black text; recolour for the dark theme. */
  --verso-code-color: #d6def5;
  --verso-code-keyword-color: #c4b5fd;
  --verso-code-const-color: #7dd3fc;
  --verso-code-var-color: #fcd9a8;
}

html { scroll-behavior: smooth; }

body {
  margin: 0;
  min-height: 100vh;
  color: var(--text);
  font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  line-height: 1.65;
  background:
    radial-gradient(125% 100% at 22% -5%, var(--navy-2), var(--navy-1) 55%, var(--navy-0) 100%)
    fixed;
}

a { color: var(--teal); text-decoration: none; }
a:hover { text-decoration: underline; }

h1, h2, h3 {
  font-family: var(--display);
  font-weight: 700;
  letter-spacing: 0.01em;
  line-height: 1.15;
}

/* ---- nav ---- */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(8, 11, 22, 0.72);
  backdrop-filter: blur(9px);
  border-bottom: 1px solid var(--line);
}
.nav-inner {
  max-width: var(--max);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.55rem 1.25rem;
}
.brand img { height: 34px; display: block; }
.nav-links a {
  margin-left: 1.5rem;
  color: var(--muted);
  font-family: var(--display);
  font-size: 0.95rem;
}
.nav-links a:hover { color: var(--text); text-decoration: none; }

main { max-width: var(--max); margin: 0 auto; padding: 0 1.25rem; }

/* ---- hero ---- */
.hero {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 2.75rem;
  align-items: center;
  padding: 4.5rem 0 3rem;
}
.hero-img {
  width: 100%;
  border-radius: 18px;
  border: 1px solid var(--line);
  box-shadow: 0 24px 70px rgba(0, 0, 0, 0.5);
}
.hero-title {
  font-size: 4.2rem;
  margin: 0;
  background: linear-gradient(120deg, #ffffff, #cfe0ff);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero-tag {
  font-family: var(--display);
  font-size: 1.55rem;
  color: var(--teal);
  margin: 0.4rem 0 1rem;
}
.hero-sub { color: var(--muted); font-size: 1.12rem; max-width: 38ch; }
.cta {
  display: inline-block;
  margin-top: 1.5rem;
  padding: 0.72rem 1.4rem;
  border-radius: 999px;
  font-family: var(--display);
  font-weight: 600;
  color: #1a1205;
  background: linear-gradient(120deg, var(--amber-1), var(--amber-2));
}
.cta:hover { text-decoration: none; filter: brightness(1.07); }

/* ---- pillars ---- */
.pillars {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
  padding: 1rem 0 2.5rem;
}
.pillar {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 1.5rem;
}
.pillar h3 { margin: 0.1rem 0 0.55rem; color: var(--amber-1); font-size: 1.15rem; }
.pillar p { margin: 0; color: var(--muted); }

/* ---- bands + cards ---- */
.band { padding: 2.75rem 0; border-top: 1px solid var(--line); }
.section-title { font-size: 1.95rem; text-align: center; margin: 0 0 1.7rem; }
.cards { display: grid; gap: 1.1rem; }
.cards.four { grid-template-columns: repeat(4, 1fr); }
.cards.three { grid-template-columns: repeat(3, 1fr); }
.card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 1.35rem;
  transition: transform 0.15s ease, border-color 0.15s ease;
}
.card h3 { margin: 0 0 0.3rem; font-size: 1.1rem; }
.card.repo { display: block; color: inherit; }
.card.repo h3 { color: var(--teal); }
.card.repo p { margin: 0.35rem 0 0; color: var(--muted); font-size: 0.95rem; }
a.card:hover { transform: translateY(-3px); border-color: var(--teal); text-decoration: none; }

/* ---- "a taste of the maths" ---- */
.taste-note {
  text-align: center;
  color: var(--muted);
  margin: -0.8rem auto 1.6rem;
  max-width: 52ch;
}
.taste pre, main pre {
  border-radius: 12px;
  border: 1px solid var(--line);
  padding: 1rem 1.1rem;
  overflow-x: auto;
}

/* ---- footer ---- */
.site-footer {
  margin-top: 3.5rem;
  border-top: 1px solid var(--line);
  background: rgba(8, 11, 22, 0.6);
}
.foot-inner { max-width: var(--max); margin: 0 auto; padding: 2.25rem 1.25rem; text-align: center; }
.foot-tag { font-family: var(--display); color: var(--teal); font-size: 1.2rem; margin: 0 0 0.7rem; }
.foot-links {
  list-style: none;
  padding: 0;
  margin: 0 0 0.7rem;
  display: flex;
  gap: 1.5rem;
  justify-content: center;
  flex-wrap: wrap;
}
.foot-links a { color: var(--muted); }
.foot-legal { color: var(--muted); font-size: 0.85rem; margin: 0; }

/* About / interior prose pages */
.frontpage { padding-bottom: 1rem; }

/* ---- lines-of-code charts ---- */
/* Statistics page: the two figures stack, each chart fills its width. */
.loc-graphs { display: flex; flex-direction: column; gap: 2rem; margin: 2rem 0; }
.loc-figure { margin: 0; }
/* The per-roadmap chart stands on its own (wider, with a legend), so it gets the same
   vertical rhythm the stacked pair has between them. */
.loc-figure-wide { margin: 2rem 0; }
.loc-graph { display: block; width: 100%; height: auto; }
.loc-figure figcaption {
  color: var(--muted);
  font-size: 0.92rem;
  text-align: center;
  margin-top: 0.6rem;
}
.loc-figure figcaption code {
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  color: var(--text);
}

/* Front-page teaser: the library chart linking through to the statistics page. */
.growth-link {
  display: block;
  max-width: 760px;
  margin: 0 auto;
  text-align: center;
}
.growth-img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 12px;
  transition: transform 0.15s;
}
.growth-link:hover { text-decoration: none; }
.growth-link:hover .growth-img { transform: translateY(-2px); }
.growth-cta {
  display: inline-block;
  margin-top: 0.9rem;
  color: var(--teal);
  font-family: var(--display);
  font-weight: 500;
}

/* ---- responsive ---- */
@media (max-width: 820px) {
  .hero { grid-template-columns: 1fr; padding: 2.75rem 0; }
  .pillars { grid-template-columns: 1fr; }
  .cards.four, .cards.three { grid-template-columns: 1fr 1fr; }
  .hero-title { font-size: 3.1rem; }
}
@media (max-width: 520px) {
  .cards.four, .cards.three { grid-template-columns: 1fr; }
}

/* ---- Verso code blocks: readable on the dark theme ---- */
.hl.lean .sort { color: var(--teal); }
.hl.lean .doc-comment, .hl.lean .comment { color: var(--muted); font-style: italic; }
.hl.lean.block {
  background: #0a0f20;
  color: var(--verso-code-color);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 1.1rem 1.25rem;
  font-size: 0.9rem;
  line-height: 1.55;
  overflow-x: auto;
}

/* ---- horizontal carousel for the code samples ---- */
.carousel { position: relative; display: flex; align-items: center; gap: 0.5rem; }
.carousel-track {
  flex: 1 1 auto;
  display: flex;
  gap: 1.25rem;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  scroll-padding: 0 0.5rem;
  padding: 0.4rem 0.25rem 1.1rem;
  scrollbar-color: var(--teal) rgba(255, 255, 255, 0.08);
}
.carousel-track > .hl.lean.block {
  flex: 0 0 min(86%, 680px);
  scroll-snap-align: center;
  margin: 0;
}
.carousel-arrow {
  flex: 0 0 auto;
  width: 2.5rem;
  height: 2.5rem;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.04);
  color: var(--text);
  font-family: var(--display);
  font-size: 1.5rem;
  line-height: 1;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s;
}
.carousel-arrow:hover { background: rgba(94, 234, 212, 0.12); border-color: var(--teal); }
@media (max-width: 640px) {
  .carousel-arrow { display: none; }
  .carousel-track > .hl.lean.block { flex-basis: 88%; }
}