:root {
  color-scheme: dark;
  --background: #0b1020;
  --card: #151c2f;
  --ink: #eaf0ff;
  --muted: #94a3b8;
  --line: #263452;
  --blue: #2f6bff;
  --cyan: #31d6c8;
  --danger: #ff8d99;
  font-family: -apple-system, BlinkMacSystemFont, "Noto Sans KR", "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }
body { margin: 0; background: var(--background); color: var(--ink); line-height: 1.65; }
a { color: var(--cyan); text-decoration: none; }
a:hover { text-decoration: underline; }
.shell { width: min(760px, calc(100% - 40px)); margin: 0 auto; }
header { border-bottom: 1px solid var(--line); background: rgba(11, 16, 32, .92); }
nav { min-height: 72px; display: flex; align-items: center; justify-content: space-between; gap: 20px; }
.brand { display: inline-flex; align-items: center; gap: 10px; color: var(--ink); font-weight: 800; }
.mark { width: 36px; height: 36px; border: 3px solid var(--blue); border-radius: 9px; display: grid; place-items: center; color: var(--cyan); font-size: 17px; }
.back { color: var(--muted); font-size: 14px; }
main { padding: 56px 0 80px; }
.eyebrow { color: var(--cyan); font: 700 12px ui-monospace, monospace; letter-spacing: .08em; }
h1 { margin: 10px 0 12px; font-size: clamp(32px, 7vw, 48px); line-height: 1.18; }
h2 { margin: 34px 0 10px; font-size: 21px; }
h3 { margin: 0; font-size: 18px; }
p, li { color: #d7def2; }
.lead { color: var(--muted); font-size: 17px; margin-bottom: 30px; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: 20px; padding: 22px; margin: 16px 0; }
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 14px; }
.button { display: inline-flex; align-items: center; justify-content: center; min-height: 48px; padding: 0 18px; border-radius: 14px; background: var(--blue); color: white; font-weight: 750; }
.button.secondary { background: var(--card); border: 1px solid var(--line); color: var(--ink); }
.button:hover { text-decoration: none; filter: brightness(1.08); }
.actions { display: flex; flex-wrap: wrap; gap: 10px; margin: 28px 0; }
.meta { color: var(--muted); font-size: 13px; }
.badge { display: inline-block; padding: 5px 10px; border-radius: 999px; color: var(--cyan); background: rgba(49, 214, 200, .1); font: 700 12px ui-monospace, monospace; }
ul { padding-left: 21px; }
li + li { margin-top: 8px; }
footer { border-top: 1px solid var(--line); padding: 24px 0 40px; color: var(--muted); font-size: 13px; }
.notice { border-left: 3px solid var(--cyan); padding-left: 16px; color: var(--muted); }
@media (max-width: 520px) { main { padding-top: 38px; } .shell { width: min(100% - 28px, 760px); } }

/* 언어 토글 — 같은 URL 이 한국어·영어를 모두 담고 CSS 로 한쪽만 보여줍니다.
   lang.js 가 <html data-lang> 을 설정하며, JS 가 없으면 한국어가 그대로 보입니다. */
/* body 하위로 한정한다 — lang.js 가 <html lang="en"> 도 설정하므로
   범위를 좁히지 않으면 선택자가 문서 전체를 숨긴다. */
body [lang="en"] { display: none; }
:root[data-lang="en"] body [lang="ko"] { display: none; }
:root[data-lang="en"] body [lang="en"] { display: revert; }
.langs { display: inline-flex; gap: 6px; margin-left: auto; }
.langs button {
  font: 700 13px inherit; cursor: pointer; color: var(--muted);
  background: transparent; border: 1px solid var(--line); border-radius: 999px;
  min-height: 32px; padding: 0 12px;
}
.langs button[aria-current="true"] { color: var(--ink); border-color: var(--cyan); }
.langs button:hover { color: var(--ink); }
header nav { display: flex; align-items: center; gap: 16px; }