:root {
  --bg: #06070d;
  --bg2: #0c0f1a;
  --card: #12162a;
  --line: #243055;
  --text: #eef1ff;
  --muted: #9aa6c7;
  --violet: #8b7cff;
  --violet2: #b4a9ff;
  --cyan: #6ee7ff;
  --max: 48rem;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
}
a { color: var(--violet2); }
a:hover { color: #fff; }
.wrap { max-width: var(--max); margin: 0 auto; padding: 1.25rem; }
.wrap-wide { max-width: 58rem; margin: 0 auto; padding: 1.25rem; }
.site-header {
  border-bottom: 1px solid var(--line);
  background: rgba(6,7,13,.94);
  position: sticky; top: 0; backdrop-filter: blur(10px); z-index: 10;
}
.site-header .wrap-wide {
  display: flex; flex-wrap: wrap; gap: 1rem;
  align-items: center; justify-content: space-between;
}
.brand {
  font-weight: 700; letter-spacing: .14em; text-transform: uppercase;
  text-decoration: none; color: var(--text); font-size: .8rem;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
}
.brand span { color: var(--violet2); }
nav {
  display: flex; flex-wrap: wrap; gap: .85rem; font-size: .84rem;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
}
nav a { color: var(--muted); text-decoration: none; }
nav a:hover { color: var(--violet2); }
.hero {
  padding: 4rem 0 3rem;
  background:
    radial-gradient(ellipse at 15% 10%, rgba(139,124,255,.22), transparent 45%),
    radial-gradient(ellipse at 85% 0%, rgba(110,231,255,.1), transparent 40%),
    linear-gradient(180deg, #0a0c16, var(--bg));
  border-bottom: 1px solid var(--line);
}
.hero h1 {
  font-size: clamp(2rem, 5vw, 3.1rem);
  line-height: 1.1; margin: .55rem 0 1rem; max-width: 18ch;
  font-weight: 600;
}
.eyebrow {
  color: var(--cyan); letter-spacing: .16em; text-transform: uppercase;
  font-size: .72rem; font-weight: 700;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
}
.lead { color: var(--muted); font-size: 1.1rem; max-width: 38rem; }
.cta-row { display: flex; flex-wrap: wrap; gap: .75rem; margin-top: 1.4rem; }
.btn {
  display: inline-block; background: var(--violet); color: #0b0c14 !important;
  text-decoration: none !important; font-weight: 700; padding: .75rem 1.15rem;
  border-radius: 8px;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  font-size: .9rem;
}
.btn.secondary {
  background: transparent; color: var(--text) !important;
  border: 1px solid var(--line);
}
section { padding: 2.6rem 0; border-bottom: 1px solid var(--line); }
h2 { font-size: 1.55rem; margin: 0 0 1rem; font-weight: 600; }
h3 {
  margin: 1.4rem 0 .45rem; font-size: 1.12rem; font-weight: 600;
}
h4 {
  margin: 1.1rem 0 .35rem; font-size: 1rem; color: var(--violet2);
  font-family: system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
}
p { color: #d5dbf0; }
.grid {
  display: grid; gap: 1rem;
  grid-template-columns: repeat(auto-fit, minmax(15rem, 1fr));
}
.card {
  background: var(--card); border: 1px solid var(--line);
  border-radius: 12px; padding: 1.1rem 1.15rem;
}
.note {
  color: var(--muted); font-size: .88rem;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
}
.formula {
  background: var(--bg2); border: 1px solid var(--line);
  border-radius: 12px; padding: 1.1rem 1.2rem; margin: 1rem 0;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  color: var(--cyan); overflow-x: auto;
}
.vars { list-style: none; padding: 0; margin: 1rem 0; }
.vars li {
  padding: .55rem 0; border-bottom: 1px solid var(--line);
  color: #d5dbf0; font-size: .95rem;
}
.vars strong {
  color: var(--violet2);
  font-family: system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
}
.site-footer {
  padding: 2rem 0 3rem; color: var(--muted); font-size: .85rem;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
}
.meta {
  color: var(--muted); font-size: .8rem; letter-spacing: .08em;
  text-transform: uppercase; margin: 2rem 0 .5rem;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
}
.blog-list { list-style: none; padding: 0; margin: 1rem 0 0; }
.blog-list li {
  border: 1px solid var(--line); border-radius: 12px;
  background: var(--card); padding: 1.1rem 1.2rem; margin-bottom: .85rem;
}
.blog-list a {
  text-decoration: none; color: var(--text); font-weight: 600;
  font-size: 1.08rem; display: block; margin-bottom: .35rem;
}
.blog-list a:hover { color: var(--violet2); }
.blog-list .meta { margin: 0 0 .4rem; }
.prose { max-width: 42rem; }
.prose h2 { font-size: 1.3rem; margin: 2rem 0 .75rem; }
.prose ul { color: #d5dbf0; padding-left: 1.2rem; }
.toc {
  background: var(--card); border: 1px solid var(--line);
  border-radius: 12px; padding: 1rem 1.15rem; margin: 1rem 0 1.5rem;
}
.toc a {
  display: block; text-decoration: none; color: var(--muted);
  padding: .25rem 0; font-size: .92rem;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
}
.toc a:hover { color: var(--violet2); }