/* Undula 사이트 — 앱과 같은 짙은 초록 바탕 한 가지(어두운 화면으로 고정), 높이 색(파랑→초록→노랑→빨강)을 포인트로.
   레이아웃: 위 고정 머리줄 → 소개(글 + 폰 화면) → 사용 순서 3단계 → 기능 → 화면 → 기기 조건·규칙 → 바닥글 */
:root {
  color-scheme: dark;
  --bg: #0b1711;
  --bg-raised: #12221a;
  --line: #223a2c;
  --fg: #eef4ef;
  --text: #d5e1d8;
  --muted: #9fb2a5;
  --low: #3f86f0;
  --ball: #5fd07f;
  --mid: #f0b43c;
  --high: #e85640;
  --radius: 18px;
  --font: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Apple SD Gothic Neo", "Noto Sans KR", "Segoe UI", Roboto, sans-serif;
  --font-display: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Apple SD Gothic Neo", "Noto Sans KR", "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--bg); color: var(--fg); font: 16px/1.65 var(--font); }
img { max-width: 100%; }
a { color: var(--ball); }
a:focus-visible, button:focus-visible, summary:focus-visible { outline: 2px solid var(--ball); outline-offset: 3px; border-radius: 6px; }

/* 한국어는 단어 중간에서 줄을 바꾸지 않는다 ("그 / 린을" 방지) */
:lang(ko) { word-break: keep-all; overflow-wrap: break-word; }

/* 언어: <html lang>에 맞는 쪽만 보인다 (site.js·머리의 짧은 스크립트가 고른다) */
html[lang="ko"] body [lang="en"], html[lang="en"] body [lang="ko"] { display: none !important; }

.wrap { max-width: 1080px; margin: 0 auto; padding-inline: 20px; }

header.site { position: sticky; top: 0; z-index: 10; border-bottom: 1px solid var(--line);
  background: rgba(11, 23, 17, 0.88); -webkit-backdrop-filter: blur(12px); backdrop-filter: blur(12px); }
header.site .wrap { display: flex; align-items: center; justify-content: space-between; gap: 12px; padding-block: 12px; }
.brand { display: flex; align-items: center; gap: 10px; color: var(--fg); text-decoration: none; font-weight: 700; font-size: 17px; }
.brand img { width: 32px; height: 32px; border-radius: 8px; }
.lang { display: inline-flex; border: 1px solid var(--line); border-radius: 999px; padding: 3px; }
.lang button { appearance: none; border: 0; background: transparent; color: var(--muted); font: inherit; font-size: 13px;
  padding: 4px 11px; border-radius: 999px; cursor: pointer; }
.lang button[aria-pressed="true"] { background: var(--bg-raised); color: var(--fg); }

/* 소개 */
.hero { display: grid; grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr); gap: 48px; align-items: center; padding-block: 64px 24px; }
.hero h1 { font: 700 clamp(38px, 6vw, 62px)/1.06 var(--font-display); letter-spacing: -0.02em; margin: 0 0 18px; text-wrap: balance; }
.hero .lead { font-size: clamp(17px, 2vw, 20px); color: var(--text); max-width: 32em; margin: 0 0 28px; }
.ramp { width: 132px; height: 6px; border-radius: 3px; margin: 0 0 26px;
  background: linear-gradient(90deg, var(--low), var(--ball), var(--mid), var(--high)); }
.eyebrow { color: var(--muted); font-size: 14px; letter-spacing: 0.06em; text-transform: uppercase; margin: 0 0 14px; }
.cta { display: flex; flex-wrap: wrap; gap: 14px; align-items: center; }
.store { display: inline-flex; align-items: center; gap: 8px; padding: 12px 20px; border-radius: 12px;
  background: var(--fg); color: var(--bg); font-weight: 650; text-decoration: none; }
.store[aria-disabled="true"] { background: transparent; color: var(--fg); border: 1px solid var(--line); cursor: default; }
.text-link { color: var(--fg); text-decoration: none; border-bottom: 1px solid var(--line); padding-block: 2px; }

.phone { width: min(300px, 72vw); margin-inline: auto; padding: 9px; border-radius: 46px; background: #040805;
  box-shadow: 0 28px 70px rgba(0, 0, 0, 0.55), inset 0 0 0 2px #26372d; }
.phone img { display: block; width: 100%; height: auto; border-radius: 37px; }

/* 구역 */
section { padding-block: 56px; scroll-margin-top: 64px; }   /* 링크로 이동해도 제목이 고정 머리줄 밑에 가리지 않게 */
section h2 { font: 700 clamp(26px, 3.4vw, 36px)/1.2 var(--font-display); letter-spacing: -0.01em; margin: 0 0 26px; text-wrap: balance; }

.steps { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 16px; list-style: none; padding: 0; margin: 0; counter-reset: step; }
.steps li { background: var(--bg-raised); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px; min-width: 0; }
.steps li::before { counter-increment: step; content: counter(step); display: inline-grid; place-items: center;
  width: 30px; height: 30px; border-radius: 50%; background: var(--ball); color: #062010; font-weight: 700; margin-bottom: 12px; }
.steps h3, .feature h3 { margin: 0 0 6px; font-size: 18px; line-height: 1.35; }
.steps p, .feature p { margin: 0; color: var(--muted); }

.features { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 16px; }
.feature { padding: 22px; border-radius: var(--radius); border: 1px solid var(--line); min-width: 0; }
.feature .swatch { display: block; width: 28px; height: 4px; border-radius: 2px; margin-bottom: 14px; background: var(--ball); }
.feature .swatch.low { background: var(--low); }
.feature .swatch.mid { background: var(--mid); }
.feature .swatch.high { background: var(--high); }
.feature .swatch.ramp-mini { background: linear-gradient(90deg, var(--low), var(--ball), var(--mid), var(--high)); }

.shots { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 28px; }
.shots figure { margin: 0; text-align: center; min-width: 0; }
.shots .phone { width: min(260px, 100%); }
.shots figcaption { color: var(--muted); font-size: 14px; margin-top: 12px; }

.note { background: var(--bg-raised); border: 1px solid var(--line); border-radius: var(--radius); padding: 24px 26px; }
.note h3 { margin: 0 0 8px; font-size: 18px; }
.note p { margin: 0 0 10px; color: var(--text); }
.note p:last-child { margin-bottom: 0; }
.two { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; }

footer.site { border-top: 1px solid var(--line); padding-block: 30px; color: var(--muted); font-size: 14px; }
footer.site .wrap { display: flex; flex-wrap: wrap; gap: 12px 24px; justify-content: space-between; align-items: center; }
footer.site nav { display: flex; flex-wrap: wrap; gap: 18px; }
footer.site a { color: var(--muted); }

/* 지원·개인정보 처리방침 */
.doc { max-width: 720px; margin: 0 auto; padding: 48px 20px 64px; }
.doc h1 { font: 700 clamp(30px, 4vw, 40px)/1.15 var(--font-display); letter-spacing: -0.01em; margin: 0 0 8px; }
.doc .meta { color: var(--muted); margin: 0 0 30px; }
.doc h2 { font-size: 21px; line-height: 1.35; margin: 38px 0 10px; }
.doc p, .doc li { color: var(--text); }
.doc ol, .doc ul { padding-left: 1.3em; }
.doc li + li { margin-top: 6px; }
.contact { display: flex; flex-wrap: wrap; gap: 6px 16px; align-items: baseline; background: var(--bg-raised);
  border: 1px solid var(--line); border-radius: var(--radius); padding: 20px 22px; }
.contact strong { font-size: 18px; }
details { border: 1px solid var(--line); border-radius: 14px; padding: 14px 18px; margin: 10px 0; background: var(--bg-raised); }
summary { cursor: pointer; font-weight: 600; color: var(--fg); }
details p { margin: 10px 0 2px; }

@media (max-width: 860px) {
  .hero { grid-template-columns: minmax(0, 1fr); gap: 36px; padding-block: 40px 8px; }
  .steps, .features, .two { grid-template-columns: minmax(0, 1fr); }
  .shots { display: flex; gap: 20px; overflow-x: auto; scroll-snap-type: x mandatory; padding-bottom: 8px; }
  .shots figure { flex: 0 0 min(240px, 72vw); scroll-snap-align: center; }
}