:root {
  --bg: #f5f8fa;
  --surface: #ffffff;
  --ink: #16232d;
  --ink-soft: #52697a;
  --border: #d7e1e7;
  --accent: #1f6f8b;
  --accent-soft: #e4f1f5;
  --green: #22664c;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #10161b;
    --surface: #1a222a;
    --ink: #e7eef2;
    --ink-soft: #93a8b5;
    --border: #2b3843;
    --accent: #6cbcda;
    --accent-soft: #1e3540;
    --green: #5fcc9f;
  }
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", "Noto Sans TC", "PingFang TC", "Microsoft JhengHei", sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.7;
  font-size: 17px;
}

body[data-lang="zh"] [data-lang="en"],
body[data-lang="en"] [data-lang="zh"] { display: none !important; }

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

.wrap { max-width: 880px; margin: 0 auto; padding: 0 20px; }

header.site {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 18px 0;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 22px;
  color: var(--ink);
  text-decoration: none;
}

.brand svg { width: 30px; height: 30px; }

.lang-switch { display: flex; gap: 6px; }
.lang-switch button {
  font: inherit;
  font-size: 14px;
  font-weight: 700;
  padding: 6px 12px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--ink);
  cursor: pointer;
}
body[data-lang="zh"] .lang-switch [data-set="zh"],
body[data-lang="en"] .lang-switch [data-set="en"] {
  background: var(--accent);
  color: var(--surface);
  border-color: var(--accent);
}

.hero { padding: 36px 0 24px; }
.hero h1 { font-size: clamp(30px, 6vw, 46px); line-height: 1.2; margin: 0 0 12px; }
.hero p { font-size: 19px; color: var(--ink-soft); max-width: 640px; margin: 0; }

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 22px;
  padding: 28px;
  margin: 22px 0;
}

.app {
  display: grid;
  grid-template-columns: 180px 1fr;
  gap: 28px;
  align-items: center;
}
.app img { width: 100%; height: auto; border-radius: 28px; border: 1px solid var(--border); }
.app h2 { margin: 0 0 6px; font-size: 28px; }
.tagline { color: var(--ink-soft); margin: 0 0 14px; }

ul.points { margin: 14px 0 0; padding-left: 20px; }
ul.points li { margin: 6px 0; }

.badge {
  display: inline-block;
  padding: 6px 14px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent);
  font-weight: 700;
  font-size: 15px;
  margin-top: 16px;
}

.note {
  font-size: 15px;
  color: var(--ink-soft);
  border-left: 4px solid var(--border);
  padding-left: 14px;
  margin: 18px 0 0;
}

h2.section { font-size: 24px; margin: 0 0 8px; }
.contact a { font-weight: 700; word-break: break-all; }

footer.site {
  padding: 28px 0 44px;
  color: var(--ink-soft);
  font-size: 15px;
  border-top: 1px solid var(--border);
  margin-top: 30px;
}
footer.site p { margin: 4px 0; }

/* privacy page */
article.policy h1 { font-size: 32px; margin: 18px 0 6px; }
article.policy h2 { font-size: 21px; margin: 28px 0 6px; }
article.policy p, article.policy li { max-width: 70ch; }
.meta { color: var(--ink-soft); font-size: 15px; margin: 0 0 18px; }

@media (max-width: 640px) {
  .app { grid-template-columns: 1fr; }
  .app img { max-width: 160px; }
  .card { padding: 22px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}