:root {
  --bg: #f5f5f7; --fg: #1d1d1f; --muted: #6e6e73; --card: #ffffff; --accent: #0071e3; --line: rgba(0,0,0,.08);
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #000000; --fg: #f5f5f7; --muted: #a1a1a6; --card: #1c1c1e; --accent: #2997ff; --line: rgba(255,255,255,.1); }
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--fg);
  font: 17px/1.5 -apple-system, BlinkMacSystemFont, "SF Pro Text", system-ui, sans-serif; -webkit-font-smoothing: antialiased; }
main { max-width: 980px; margin: 0 auto; padding: 72px 22px 96px; }
nav { display: flex; justify-content: space-between; align-items: center; max-width: 980px; margin: 0 auto; padding: 18px 22px; }
nav a { color: var(--fg); text-decoration: none; font-weight: 600; }
nav .links a { color: var(--muted); font-weight: 400; margin-left: 22px; font-size: 14px; }
h1 { font: 700 56px/1.07 -apple-system, "SF Pro Display", system-ui; letter-spacing: -.02em; margin: 0 0 16px; }
h2 { font: 600 32px/1.1 -apple-system, "SF Pro Display", system-ui; letter-spacing: -.01em; margin: 64px 0 16px; }
.lead { font-size: 21px; color: var(--muted); max-width: 640px; }
.button { display: inline-block; background: var(--accent); color: #fff; text-decoration: none; padding: 12px 22px;
  border-radius: 980px; font-weight: 500; margin: 24px 12px 0 0; }
.button.secondary { background: transparent; color: var(--accent); border: 1px solid var(--accent); }
.hero-image { width: 100%; border-radius: 18px; margin-top: 48px; box-shadow: 0 20px 60px rgba(0,0,0,.12); }
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 16px; }
/* Four cards read as 2 × 2, never 3 + 1. */
.grid.two { grid-template-columns: repeat(2, 1fr); }
@media (max-width: 640px) { .grid.two { grid-template-columns: 1fr; } }
.card { background: var(--card); border-radius: 18px; padding: 24px; border: 1px solid var(--line); }
.card h3 { margin: 0 0 6px; font-size: 19px; }
.card p { margin: 0; color: var(--muted); font-size: 15px; }
.fine { color: var(--muted); font-size: 13px; }
footer { border-top: 1px solid var(--line); max-width: 980px; margin: 0 auto; padding: 24px 22px; color: var(--muted); font-size: 13px; }
footer a { color: var(--muted); margin-right: 16px; }
.placeholder { border: 1px dashed var(--muted); border-radius: 12px; padding: 16px; color: var(--muted); }
.steps { max-width: 680px; padding-left: 22px; }
.steps li { margin: 10px 0; }
.perf { max-width: 680px; margin-top: 16px; padding: 16px 20px; background: var(--card); border: 1px solid var(--line); border-radius: 12px; font-size: 15px; }