:root {
  --bg: #0b1020;
  --panel: #121a2b;
  --text: #eef3ff;
  --muted: #a9b4c8;
  --accent: #6ea8fe;
  --line: #24304a;
  --max: 860px;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans KR",
               Roboto, Helvetica, Arial, sans-serif;
  background: linear-gradient(180deg, #0b1020 0%, #0d1324 100%);
  color: var(--text);
  line-height: 1.7;
}
a { color: var(--accent); }
header {
  border-bottom: 1px solid var(--line);
  background: rgba(11,16,32,.9);
  position: sticky;
  top: 0;
  backdrop-filter: blur(10px);
}
.nav {
  max-width: var(--max);
  margin: 0 auto;
  padding: 16px 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
}
.brand { font-weight: 700; letter-spacing: .2px; }
.navlinks { display: flex; gap: 16px; flex-wrap: wrap; }
.navlinks a { text-decoration: none; color: var(--muted); }
.navlinks a:hover { color: var(--text); }
main {
  max-width: var(--max);
  margin: 0 auto;
  padding: 56px 20px 72px;
}
.hero { padding: 36px 0 28px; }
.kicker {
  color: var(--accent);
  font-size: .95rem;
  font-weight: 700;
  letter-spacing: .08em;
  text-transform: uppercase;
}
h1, h2, h3 { line-height: 1.25; }
h1 { font-size: clamp(2.2rem, 6vw, 4.4rem); margin: 12px 0 18px; }
h2 { margin-top: 40px; font-size: 1.5rem; }
.lead { font-size: 1.14rem; color: var(--muted); max-width: 720px; }
.card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 22px;
  margin: 18px 0;
}
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 14px;
}
.small { color: var(--muted); font-size: .94rem; }
ul { padding-left: 1.25rem; }
code {
  background: #0a0f1b;
  border: 1px solid var(--line);
  padding: .15rem .4rem;
  border-radius: 6px;
}
footer {
  border-top: 1px solid var(--line);
  color: var(--muted);
}
.footer-inner {
  max-width: var(--max);
  margin: 0 auto;
  padding: 24px 20px 40px;
}
.notice {
  border-left: 4px solid var(--accent);
  padding: 14px 16px;
  background: #10182a;
  border-radius: 10px;
}
@media (max-width: 640px) {
  .nav { align-items: flex-start; flex-direction: column; }
}