/* prebidhub.com public site. No scripts, no fonts from elsewhere, no cookies. */
:root {
  --bg: #ffffff; --bg-soft: #f5f7fb; --ink: #0f172a; --ink-2: #334155; --muted: #64748b; --line: #e2e8f0;
  --accent: #2453d4; --accent-hover: #1b43b3; --accent-subtle: #e9effd; --on-accent: #ffffff;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0c0f14; --bg-soft: #131823; --ink: #e8edf5; --ink-2: #c2ccda; --muted: #8b97a8; --line: #232b38;
    --accent: #6d98ff; --accent-hover: #8badff; --accent-subtle: #1a2640; --on-accent: #0c0f14;
  }
}
* { box-sizing: border-box; margin: 0; padding: 0; }
html { -webkit-text-size-adjust: 100%; }
body { background: var(--bg); color: var(--ink); font: 16px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif; }
a { color: var(--accent); }
a:hover { color: var(--accent-hover); }
.wrap { max-width: 1040px; margin: 0 auto; padding: 0 20px; }

header.top { border-bottom: 1px solid var(--line); }
header.top .wrap { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 18px; color: var(--ink); text-decoration: none; }
.brand img { width: 28px; height: 28px; }
.btn { display: inline-block; padding: 9px 16px; border-radius: 8px; background: var(--accent); color: var(--on-accent); font-weight: 600; text-decoration: none; font-size: 15px; }
.btn:hover { background: var(--accent-hover); color: var(--on-accent); }
.btn.ghost { background: transparent; color: var(--accent); border: 1px solid var(--line); }
.btn.ghost:hover { background: var(--accent-subtle); color: var(--accent); }

.hero { padding-top: 72px; padding-bottom: 56px; }
.hero h1 { font-size: clamp(32px, 5vw, 48px); line-height: 1.12; letter-spacing: -0.02em; max-width: 760px; }
.hero p { font-size: 19px; color: var(--ink-2); margin-top: 18px; max-width: 680px; }
.hero .cta { margin-top: 28px; display: flex; gap: 12px; flex-wrap: wrap; }
.hero .note { font-size: 14px; color: var(--muted); margin-top: 14px; }

section { padding: 48px 0; }
section.soft { background: var(--bg-soft); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
h2 { font-size: 26px; letter-spacing: -0.01em; }
.lead { color: var(--ink-2); margin-top: 8px; max-width: 700px; }

.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; margin-top: 28px; counter-reset: s; }
.steps li { list-style: none; counter-increment: s; background: var(--bg); border: 1px solid var(--line); border-radius: 12px; padding: 20px; }
.steps li::before { content: counter(s); display: inline-flex; width: 28px; height: 28px; border-radius: 50%; background: var(--accent); color: var(--on-accent); font-weight: 700; font-size: 14px; align-items: center; justify-content: center; }
.steps h3, .grid h3 { font-size: 17px; margin-top: 10px; }
.steps p, .grid p { color: var(--ink-2); font-size: 15px; margin-top: 6px; }

.grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; margin-top: 28px; }
.grid > div { border: 1px solid var(--line); border-radius: 12px; padding: 20px; }
.grid h3 { margin-top: 0; }

.about { display: grid; grid-template-columns: 1.2fr 1fr; gap: 32px; align-items: start; }
.about p { color: var(--ink-2); margin-top: 10px; }
.facts { border: 1px solid var(--line); border-radius: 12px; padding: 20px; font-size: 15px; }
.facts dt { color: var(--muted); font-size: 13px; text-transform: uppercase; letter-spacing: .05em; margin-top: 12px; }
.facts dt:first-child { margin-top: 0; }
.facts dd { color: var(--ink); }

footer { border-top: 1px solid var(--line); padding: 28px 0 40px; color: var(--muted); font-size: 14px; }
footer .wrap { display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; }
footer nav a { color: var(--muted); margin-right: 18px; }
footer .tm { width: 100%; font-size: 13px; }

/* text pages */
.doc { padding-top: 48px; padding-bottom: 64px; max-width: 760px; }
.doc h1 { font-size: 34px; letter-spacing: -0.02em; }
.doc .updated { color: var(--muted); font-size: 14px; margin-top: 6px; }
.doc h2 { font-size: 20px; margin-top: 32px; }
.doc p, .doc li { color: var(--ink-2); margin-top: 10px; }
.doc ul { padding-left: 20px; }
.doc table { border-collapse: collapse; width: 100%; margin-top: 12px; font-size: 15px; }
.doc th, .doc td { text-align: left; vertical-align: top; padding: 8px 10px; border-bottom: 1px solid var(--line); }
.doc th { color: var(--muted); font-weight: 600; font-size: 13px; text-transform: uppercase; letter-spacing: .04em; }

@media (max-width: 760px) {
  .steps, .grid, .about { grid-template-columns: 1fr; }
  .hero { padding-top: 48px; padding-bottom: 40px; }
  .doc table { font-size: 14px; }
}