:root {
  --bg: #f7f2e8;
  --panel: #fffdf8;
  --ink: #2e2a25;
  --sub: #6f665b;
  --line: #e6dccb;
  --accent: #b5452f;
  --frame: #2e2a25;
  --radius: 14px;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #1d1b18;
    --panel: #282521;
    --ink: #eee7da;
    --sub: #b3a999;
    --line: #3d3832;
    --accent: #e0795f;
    --frame: #0f0e0c;
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: "Hiragino Sans", "Yu Gothic UI", "Yu Gothic", "Meiryo", system-ui, sans-serif;
  line-height: 1.8;
  font-size: 16px;
}
a { color: var(--accent); }
img { max-width: 100%; }

.wrap { max-width: 1080px; margin: 0 auto; padding: 0 16px; }

/* Header / footer */
.site-header { border-bottom: 1px solid var(--line); background: var(--panel); }
.site-header .wrap { display: flex; align-items: center; gap: 16px; min-height: 60px; flex-wrap: wrap; }
.logo { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 18px; color: var(--ink); text-decoration: none; }
.logo img { width: 32px; height: 32px; border-radius: 8px; }
.site-nav { margin-left: auto; display: flex; gap: 16px; font-size: 14px; }
.site-nav a { color: var(--sub); text-decoration: none; }
.site-nav a:hover { color: var(--accent); }

.site-footer { margin-top: 64px; padding: 32px 0 48px; border-top: 1px solid var(--line); color: var(--sub); font-size: 14px; }
.site-footer nav { display: flex; gap: 20px; flex-wrap: wrap; margin-bottom: 8px; }
.site-footer a { color: var(--sub); }

/* Home */
.hero { padding: 48px 0 24px; }
.hero h1 { font-size: clamp(26px, 5vw, 38px); margin: 0 0 8px; letter-spacing: 0.04em; }
.hero p { margin: 0; color: var(--sub); max-width: 640px; }
.install-btn { margin-top: 20px; border: 1px solid var(--accent); background: transparent; color: var(--accent); font: inherit; font-size: 14px; padding: 8px 18px; border-radius: 999px; cursor: pointer; }
.install-btn[hidden] { display: none; }

.cat-title { font-size: 20px; margin: 40px 0 16px; padding-left: 12px; border-left: 4px solid var(--accent); }
.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 16px; }
.card {
  display: flex; gap: 14px; align-items: flex-start;
  background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 16px; color: var(--ink); text-decoration: none;
  transition: transform .15s ease, box-shadow .15s ease;
}
.card:hover { transform: translateY(-2px); box-shadow: 0 6px 18px rgba(0,0,0,.08); }
.card img { width: 56px; height: 56px; border-radius: 12px; flex: none; }
.card h3 { margin: 0 0 2px; font-size: 16px; }
.card p { margin: 0; font-size: 13px; color: var(--sub); line-height: 1.6; }

/* App page */
.breadcrumb { font-size: 13px; color: var(--sub); margin: 20px 0 0; }
.breadcrumb a { color: var(--sub); }
.app-head { display: flex; gap: 16px; align-items: center; margin: 16px 0 24px; }
.app-head img { width: 72px; height: 72px; border-radius: 16px; flex: none; }
.app-head h1 { margin: 0; font-size: clamp(22px, 4vw, 30px); line-height: 1.3; }
.app-head p { margin: 4px 0 0; color: var(--sub); }

.app-layout { display: grid; grid-template-columns: 420px 1fr; gap: 40px; align-items: start; }
.app-stage { position: sticky; top: 16px; }
.phone {
  background: var(--frame); border-radius: 32px; padding: 10px;
  box-shadow: 0 10px 30px rgba(0,0,0,.18);
}
.phone iframe { display: block; width: 100%; height: min(780px, calc(100vh - 120px)); min-height: 560px; border: 0; border-radius: 24px; background: #fff; }
.app-stage .open-full { display: block; text-align: center; margin-top: 10px; font-size: 14px; }

.article { min-width: 0; }
.article .lead { font-size: 17px; margin-top: 0; }
.article h2 { font-size: 20px; margin: 36px 0 12px; padding-bottom: 6px; border-bottom: 1px solid var(--line); }
.article ul, .article ol { padding-left: 1.4em; }
.article li { margin: 4px 0; }
.faq dt { font-weight: 700; margin-top: 16px; }
.faq dt::before { content: "Q. "; color: var(--accent); }
.faq dd { margin: 4px 0 0; }
.faq dd::before { content: "A. "; color: var(--sub); font-weight: 700; }

.related { margin-top: 48px; }

/* Plain text pages */
.doc { max-width: 760px; padding-top: 24px; }
.doc h1 { font-size: 28px; }
.doc h2 { font-size: 19px; margin-top: 32px; }

@media (max-width: 860px) {
  .app-layout { grid-template-columns: 1fr; gap: 24px; }
  .app-stage { position: static; }
  .phone { padding: 0; background: none; box-shadow: none; border-radius: 0; }
  .phone iframe { height: 80vh; min-height: 520px; border-radius: var(--radius); border: 1px solid var(--line); }
  .site-nav { margin-left: 0; width: 100%; padding-bottom: 10px; }
}