:root {
  --page: #f9f9f7; --surface: #fcfcfb; --ink: #0b0b0b; --ink-2: #52514e;
  --muted: #898781; --grid: #e1e0d9; --border: rgba(11,11,11,.10);
  --blue: #2a78d6; --blue-deep: #1c5cab;
}
@media (prefers-color-scheme: dark) {
  :root:where(:not([data-theme="light"])) {
    --page: #0d0d0d; --surface: #1a1a19; --ink: #fff; --ink-2: #c3c2b7;
    --muted: #898781; --grid: #2c2c2a; --border: rgba(255,255,255,.10);
    --blue: #3987e5; --blue-deep: #86b6ef;
  }
}
body { background: var(--page); color: var(--ink); margin: 0;
       font-family: system-ui, -apple-system, "Segoe UI", sans-serif; line-height: 1.65; }
header.mast { display: flex; align-items: baseline; gap: 14px; flex-wrap: wrap;
              border-bottom: 3px solid var(--ink); padding: 18px 0 14px; }
main, header.mast { max-width: 760px; margin: 0 auto; padding-left: 20px; padding-right: 20px; }
main { padding-top: 36px; padding-bottom: 80px; }
.brand { font-size: 13px; font-weight: 800; letter-spacing: .3em; text-transform: uppercase;
         color: var(--blue); text-decoration: none; }
.doc { font-size: 12px; letter-spacing: .14em; text-transform: uppercase; color: var(--muted); font-weight: 600; }
h1 { font-size: clamp(26px, 4.4vw, 36px); line-height: 1.15; margin: 8px 0 10px;
     font-weight: 800; text-wrap: balance; letter-spacing: -.01em; }
h2 { font-size: 20px; margin: 34px 0 10px; font-weight: 800; text-wrap: balance; }
h2 a { color: inherit; text-decoration: none; }
h2 a:hover { color: var(--blue-deep); }
p, li { max-width: 68ch; }
.kicker { font-size: 11px; letter-spacing: .22em; text-transform: uppercase;
          color: var(--blue); font-weight: 800; margin: 0; }
.dek { font-size: 17px; color: var(--ink-2); margin: 0 0 12px; }
.meta { color: var(--muted); font-size: 13px; margin: 10px 0 0; }
.formula { background: var(--surface); border: 1px solid var(--border); border-radius: 8px;
           padding: 12px 16px; font-weight: 700; font-size: 15px; }
.card { border-top: 1px solid var(--grid); padding: 26px 0 22px; margin-top: 6px; }
.card:first-of-type { border-top: none; }
.faq details { border: 1px solid var(--grid); border-radius: 8px; padding: 12px 16px;
                margin: 8px 0; background: var(--page); }
.faq summary { cursor: pointer; font-weight: 700; }
.faq p { margin: 8px 0 0; color: var(--ink-2); }
.endnav { display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap;
          border-top: 1px solid var(--grid); margin-top: 44px; padding-top: 16px;
          font-size: 13.5px; }
.endnav a { color: var(--blue); font-weight: 700; text-decoration: none; }
.endnav a:hover { text-decoration: underline; }