:root {
  --bg: #f6f7fb;
  --card: #ffffff;
  --text: #14171f;
  --sub: #5b6475;
  --line: #e3e6ee;
  --brand: #1f6fe5;
  --hero1: #0e265c;
  --hero2: #060e24;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b0e15;
    --card: #141925;
    --text: #e8ebf2;
    --sub: #9aa3b5;
    --line: #232a3a;
    --brand: #5c9bff;
  }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.7 -apple-system, BlinkMacSystemFont, "Apple SD Gothic Neo", "Pretendard", "Segoe UI", Roboto, sans-serif;
}
a { color: var(--brand); }
header.top {
  display: flex; align-items: center; justify-content: space-between; gap: 12px;
  max-width: 820px; margin: 0 auto; padding: 18px 16px;
}
header.top .brand { display: flex; align-items: center; gap: 10px; font-weight: 700; color: var(--text); text-decoration: none; font-size: 18px; }
header.top .brand img { width: 32px; height: 32px; border-radius: 8px; }
.lang { display: flex; gap: 4px; font-size: 14px; }
.lang button {
  border: 1px solid var(--line); background: var(--card); color: var(--sub);
  border-radius: 999px; padding: 4px 12px; cursor: pointer; font: inherit;
}
.lang button[aria-pressed="true"] { color: var(--text); border-color: var(--brand); }
main { max-width: 820px; margin: 0 auto; padding: 8px 16px 48px; }
.doc { background: var(--card); border: 1px solid var(--line); border-radius: 16px; padding: 28px 24px; }
.doc h1 { font-size: 28px; line-height: 1.3; margin: 0 0 6px; }
.doc .date { color: var(--sub); font-size: 14px; margin-bottom: 24px; }
.doc h2 { font-size: 18px; margin: 28px 0 6px; }
.doc p, .doc li { color: var(--text); }
.doc ul { padding-left: 20px; }
.hero {
  background: linear-gradient(180deg, var(--hero1), var(--hero2));
  color: #fff; border-radius: 20px; padding: 40px 24px; text-align: center;
}
.hero img { width: 96px; height: 96px; border-radius: 22px; box-shadow: 0 10px 30px rgba(0,0,0,.35); }
.hero h1 { font-size: 34px; margin: 18px 0 8px; line-height: 1.25; }
.hero p { color: #c5d3f0; margin: 0 auto; max-width: 520px; }
.features { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 12px; margin-top: 16px; }
.features div { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 16px; }
.features b { display: block; margin-bottom: 4px; }
.features span { color: var(--sub); font-size: 14px; }
footer { max-width: 820px; margin: 0 auto; padding: 0 16px 40px; color: var(--sub); font-size: 14px; display: flex; flex-wrap: wrap; gap: 16px; }
footer a { color: var(--sub); }
[data-lang] { display: none; }
html[lang="ko"] [data-lang="ko"], html[lang="en"] [data-lang="en"] { display: revert; }