/* MODELING-2026-06-26 — gentoologic.com/modeling, an AI reference hub.
   Gentoo palette: brand #1BA8D8 / deep #0D8AB8 / navy #0B2440 / ink #0D2A4A. */
:root {
  --brand: #1BA8D8;
  --brand-deep: #0D8AB8;
  --navy: #0B2440;
  --navy-2: #143A63;
  --soft: #D6F0F9;
  --ink: #0D2A4A;
  --muted: #6E869A;
  --line: #E4EAF0;
  --bg: #F7FAFC;
  --card: #FFFFFF;
}
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Inter, Roboto, Helvetica, Arial, sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--brand-deep); text-decoration: none; }
a:hover { text-decoration: underline; }
.modeling-shell { max-width: 1080px; margin: 0 auto; padding: 0 22px 64px; }

/* topbar */
.topbar { display: flex; align-items: center; justify-content: space-between; gap: 16px; padding: 18px 0; flex-wrap: wrap; }
.brand img { height: 30px; display: block; }
.product-nav { display: flex; gap: 18px; flex-wrap: wrap; }
.product-nav a { color: var(--muted); font-size: 14px; font-weight: 600; }
.product-nav a:hover { color: var(--ink); text-decoration: none; }
.product-nav a[aria-current="page"] { color: var(--brand-deep); }

/* hero */
.hero {
  margin: 18px 0 34px; padding: 44px 40px; border-radius: 22px;
  background: radial-gradient(120% 140% at 0% 0%, var(--navy-2) 0%, var(--navy) 60%);
  color: #fff;
}
.eyebrow { margin: 0 0 10px; font-size: 12px; letter-spacing: .14em; text-transform: uppercase; color: var(--brand); font-weight: 700; }
.hero h1 { margin: 0 0 14px; font-size: clamp(30px, 5vw, 50px); line-height: 1.05; letter-spacing: -.02em; }
.hero h1 span { color: var(--brand); }
.hero .lede { margin: 0 0 22px; max-width: 720px; font-size: 16.5px; color: #C9DCEC; }
.jump { display: flex; gap: 10px; flex-wrap: wrap; }
.jump a {
  font-size: 13px; font-weight: 600; color: #fff; background: rgba(255,255,255,.10);
  border: 1px solid rgba(255,255,255,.18); padding: 7px 14px; border-radius: 999px;
}
.jump a:hover { background: var(--brand); border-color: var(--brand); text-decoration: none; }

/* blocks */
.block { margin: 38px 0; }
.block-head { margin-bottom: 16px; }
.block-head h2 { margin: 0 0 4px; font-size: 22px; letter-spacing: -.01em; }
.block-head p { margin: 0; color: var(--muted); font-size: 14.5px; max-width: 760px; }

.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 14px; }
.grid.concepts { grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); }
.card {
  background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 16px 17px;
  transition: border-color .15s, box-shadow .15s, transform .15s;
}
.card:hover { border-color: var(--brand); box-shadow: 0 8px 26px rgba(13,42,74,.08); transform: translateY(-1px); }
.card.wide { grid-column: 1 / -1; }
.card h3 { margin: 0 0 6px; font-size: 15.5px; color: var(--ink); }
.card p { margin: 0; font-size: 13.5px; color: #44607A; }
.card code { font-size: 12px; background: var(--soft); color: var(--brand-deep); padding: 1px 5px; border-radius: 4px; }
.tag {
  display: inline-block; margin-top: 10px; font-size: 11px; font-weight: 600; letter-spacing: .02em;
  color: var(--brand-deep); background: var(--soft); padding: 3px 9px; border-radius: 999px;
}

/* footer */
.foot { margin-top: 46px; padding-top: 20px; border-top: 1px solid var(--line); }
.foot p { margin: 0; font-size: 13px; color: var(--muted); }

@media (max-width: 620px) {
  .hero { padding: 32px 22px; }
  .topbar { gap: 10px; }
}