:root{
  --bg:#ffffff;
  --ink:#0f172a;
  --muted:#475569;
  --line:#e5e7eb;
  --panel:#ffffff;
  --panel2:#f8fafc;
  --link:#2563eb;
}
*{box-sizing:border-box}
body{
  margin:0;
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Arial,sans-serif;
  background:var(--bg);
  color:var(--ink);
  line-height:1.5;
}
a{color:var(--link);text-decoration:none}
a:hover{text-decoration:underline}
.top{
  position:sticky; top:0;
  background:rgba(255,255,255,.92);
  backdrop-filter: blur(10px);
  border-bottom:1px solid var(--line);
  z-index:10;
}
.nav{
  max-width:1000px;
  margin:0 auto;
  padding:14px 18px;
  display:flex;
  gap:14px;
  align-items:center;
  justify-content:space-between;
  flex-wrap:wrap;
}
.brand{font-weight:700; letter-spacing:.01em}
.menu{display:flex;flex-wrap:wrap;gap:10px;font-size:13px;color:var(--muted)}
.menu a{color:var(--muted);padding:6px 8px;border-radius:10px}
.menu a:hover{color:var(--ink);background:var(--panel2);text-decoration:none}
.wrap{max-width:1000px;margin:0 auto;padding:64px 18px}
h1{font-size:44px;line-height:1.05;margin:0 0 10px;font-weight:750}
.sub{font-size:18px;color:var(--muted);margin:0 0 26px;max-width:78ch}
.rule{height:1px;background:var(--line);margin:34px 0}
h2{font-size:16px;margin:0 0 10px;font-weight:750;letter-spacing:.02em}
p{margin:0 0 10px;color:var(--muted)}
.grid{display:grid;grid-template-columns:1fr;gap:12px}
@media (min-width:900px){.grid{grid-template-columns:1fr 1fr}}
.card{
  border:1px solid var(--line);
  border-radius:16px;
  padding:16px;
  background:var(--panel);
  box-shadow: 0 1px 0 rgba(15,23,42,.04);
}
.card strong{display:block;color:var(--ink);margin-bottom:6px}
.small{font-size:13px;color:var(--muted)}
.kbd{
  font-family:ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,monospace;
  font-size:12px;background:var(--panel2);
  border:1px solid var(--line);
  padding:2px 6px;border-radius:8px;color:var(--ink)
}
.btn{
  display:inline-flex;align-items:center;justify-content:center;
  padding:10px 12px;border-radius:14px;
  border:1px solid var(--line);
  background:var(--ink);
  color:#ffffff;
  text-decoration:none;
  font-weight:750;
}
.btn:hover{opacity:.92;text-decoration:none}
input, textarea, select{
  width:100%;
  padding:10px 12px;
  border-radius:14px;
  border:1px solid var(--line);
  background:#ffffff;
  color:var(--ink);
  outline:none;
}
label{display:block;font-size:13px;color:var(--muted);margin:10px 0 6px}
textarea{min-height:120px;resize:vertical}
.footer{
  margin-top:50px;border-top:1px solid var(--line);padding-top:16px;
  font-size:12px;color:var(--muted)
}