/* CARV landing — self-contained, system fonts only (no external requests) */
:root {
  --bg: #ffffff;
  --surface: #f5f5f7;
  --card: #ffffff;
  --text: #1c1c1e;
  --muted: #5f5f66;
  --line: #e4e4e8;
  --accent: #3f51b5;
  --accent-text: #ffffff;
  --ruby: #3f51b5;
  --shadow: 0 1px 2px rgb(0 0 0 / 6%), 0 8px 24px rgb(0 0 0 / 6%);
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #18181b;
    --surface: #212124;
    --card: #26262a;
    --text: #f2f2f5;
    --muted: #a9a9b3;
    --line: #34343a;
    --accent: #9aa8ff;
    --accent-text: #15162b;
    --ruby: #b3bdff;
    --shadow: 0 1px 2px rgb(0 0 0 / 40%), 0 8px 24px rgb(0 0 0 / 30%);
  }
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 17px/1.6 -apple-system, BlinkMacSystemFont, "Apple SD Gothic Neo", "Hiragino Sans", "Noto Sans KR", "Noto Sans JP", "Malgun Gothic", "Segoe UI", Roboto, sans-serif;
  word-break: keep-all;
  overflow-wrap: anywhere;
}

a { color: var(--accent); }
a:focus-visible, button:focus-visible { outline: 3px solid var(--accent); outline-offset: 2px; border-radius: 6px; }

.wrap { max-width: 40rem; margin: 0 auto; padding: 0 16px; }
.wide { max-width: 64rem; margin: 0 auto; padding: 0 16px; }

/* Header */
.site-header { border-bottom: 1px solid var(--line); }
.site-header .wide { display: flex; align-items: center; justify-content: space-between; gap: 12px; min-height: 56px; }
.brand { display: inline-flex; align-items: center; gap: 10px; color: var(--text); text-decoration: none; font-weight: 700; }
.brand img { border-radius: 9px; }
.lang { font-size: 15px; color: var(--muted); }
.lang a { color: var(--muted); padding: 10px 4px; }
.lang [aria-current] { color: var(--text); font-weight: 600; text-decoration: none; }

/* Hero */
.hero { text-align: center; padding: 56px 0 32px; }
.hero img { border-radius: 26px; box-shadow: var(--shadow); }
.hero h1 { font-size: clamp(30px, 6vw, 44px); line-height: 1.25; margin: 20px 0 12px; letter-spacing: -0.02em; }
.hero p.lead { font-size: 19px; color: var(--muted); margin: 0 auto 28px; max-width: 34rem; }

.actions { display: flex; flex-wrap: wrap; justify-content: center; gap: 12px; }
.btn {
  display: inline-flex; align-items: center; justify-content: center; min-height: 48px; padding: 12px 22px;
  border-radius: 12px; font-weight: 600; text-decoration: none; border: 1px solid var(--line); color: var(--text); background: var(--card);
}
.btn.primary { background: var(--accent); color: var(--accent-text); border-color: transparent; }
.subtle { font-size: 15px; color: var(--muted); margin-top: 14px; }

/* Example card */
.example { padding: 24px 0 48px; }
.flashcard {
  max-width: 30rem; margin: 0 auto; background: var(--card); border: 1px solid var(--line); border-radius: 20px;
  box-shadow: var(--shadow); padding: 28px 24px; text-align: center;
}
.flashcard .tag { display: inline-block; font-size: 13px; padding: 2px 10px; border-radius: 99px; background: var(--accent); color: var(--accent-text); }
.flashcard .front { font-size: 26px; line-height: 2.2; margin: 18px 0 6px; font-weight: 600; }
.flashcard rt { font-size: 12px; color: var(--ruby); font-weight: 500; }
.flashcard .back { border-top: 1px dashed var(--line); margin-top: 14px; padding-top: 14px; text-align: left; }
.flashcard .back p { margin: 4px 0; }
.flashcard .kana { color: var(--muted); }
.flashcard .info { font-size: 15px; color: var(--muted); }
.caption { text-align: center; color: var(--muted); font-size: 14px; margin-top: 12px; }

/* Sections */
section h2 { font-size: 26px; line-height: 1.3; margin: 0 0 20px; letter-spacing: -0.01em; }
.band { background: var(--surface); padding: 56px 0; }
.plain { padding: 56px 0; }
.features { display: grid; gap: 16px; grid-template-columns: 1fr; }
@media (min-width: 720px) { .features { grid-template-columns: 1fr 1fr; } }
.feature { background: var(--card); border: 1px solid var(--line); border-radius: 16px; padding: 20px; }
.feature h3 { margin: 0 0 6px; font-size: 18px; }
.feature p { margin: 0; color: var(--muted); }

ol.steps { padding-left: 1.3em; }
ol.steps li { margin: 8px 0; }

dl.details { display: grid; grid-template-columns: max-content 1fr; gap: 8px 20px; margin: 0; }
dl.details dt { color: var(--muted); }
dl.details dd { margin: 0; }

details.faq { border-bottom: 1px solid var(--line); padding: 14px 0; }
details.faq summary { cursor: pointer; font-weight: 600; min-height: 44px; display: flex; align-items: center; }
details.faq p { color: var(--muted); margin: 8px 0 0; }

/* Documents (privacy, terms, deletion) */
.doc { padding: 40px 0 56px; }
.doc h1 { font-size: 30px; line-height: 1.3; margin: 0 0 8px; }
.doc .meta { color: var(--muted); margin: 0 0 28px; }
.doc h2 { font-size: 21px; margin: 36px 0 10px; }
.doc h3 { font-size: 17px; margin: 20px 0 6px; }
.doc table { width: 100%; border-collapse: collapse; font-size: 15px; margin: 8px 0; display: block; overflow-x: auto; }
.doc th, .doc td { border: 1px solid var(--line); padding: 8px 10px; text-align: left; vertical-align: top; }
.doc th { background: var(--surface); }
.note { background: var(--surface); border-radius: 12px; padding: 12px 16px; color: var(--muted); }

/* Footer */
.site-footer { border-top: 1px solid var(--line); padding: 28px 0 40px; color: var(--muted); font-size: 15px; }
.site-footer nav { display: flex; flex-wrap: wrap; gap: 4px 18px; margin-bottom: 10px; }
.site-footer a { color: var(--muted); display: inline-block; padding: 6px 0; }

@media (prefers-reduced-motion: no-preference) {
  .btn { transition: transform .15s ease; }
  .btn:hover { transform: translateY(-1px); }
}