:root {
  --bg: #ffffff;
  --fg: #111111;
  --muted: #6b6b6b;
  --line: #e8e8e8;
  --card: #fafafa;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0c0c0c;
    --fg: #f4f4f4;
    --muted: #9a9a9a;
    --line: #1f1f1f;
    --card: #141414;
  }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans Thai", Roboto, sans-serif;
  line-height: 1.5;
}
.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 24px;
  max-width: 960px;
  margin: 0 auto;
}
.brand { font-weight: 700; font-size: 20px; text-decoration: none; color: var(--fg); letter-spacing: -0.02em; }
.lang { display: flex; gap: 6px; align-items: center; color: var(--muted); font-size: 14px; }
.lang button {
  background: none; border: none; color: var(--muted); cursor: pointer;
  font: inherit; padding: 2px 4px;
}
.lang button.active { color: var(--fg); font-weight: 600; }
main { max-width: 960px; margin: 0 auto; padding: 0 24px; }
.hero { padding: 56px 0 40px; text-align: center; }
.hero h1 { font-size: clamp(30px, 6vw, 48px); line-height: 1.1; letter-spacing: -0.03em; margin: 0 0 16px; }
.hero .sub { font-size: clamp(16px, 2.4vw, 19px); color: var(--muted); max-width: 620px; margin: 0 auto 28px; }
.badges { display: flex; gap: 10px; justify-content: center; flex-wrap: wrap; }
.badge {
  display: inline-block; padding: 10px 16px; border: 1px solid var(--line);
  border-radius: 10px; font-size: 14px; color: var(--muted);
}
.features {
  display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px;
  padding: 24px 0 64px;
}
@media (max-width: 640px) { .features { grid-template-columns: 1fr; } }
.card { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 22px; }
.card h3 { margin: 0 0 8px; font-size: 18px; letter-spacing: -0.01em; }
.card p { margin: 0; color: var(--muted); font-size: 15px; }
footer {
  border-top: 1px solid var(--line); max-width: 960px; margin: 0 auto;
  padding: 28px 24px 48px; text-align: center;
}
.legal { display: flex; gap: 20px; justify-content: center; flex-wrap: wrap; margin-bottom: 14px; }
.legal a { color: var(--fg); text-decoration: none; font-size: 14px; }
.legal a:hover { text-decoration: underline; }
.copyright { color: var(--muted); font-size: 13px; margin: 0; }

/* legal pages */
.doc { max-width: 760px; margin: 0 auto; padding: 0 24px 64px; }
.doc h1 { font-size: 32px; letter-spacing: -0.02em; }
.doc h2 { font-size: 20px; margin-top: 32px; }
.doc p, .doc li { color: var(--fg); font-size: 15px; }
.doc .meta { color: var(--muted); font-size: 14px; }
.notice {
  background: var(--card); border: 1px solid var(--line); border-radius: 10px;
  padding: 14px 16px; font-size: 14px; color: var(--muted); margin: 20px 0;
}
.back { display: inline-block; margin: 24px 0; color: var(--muted); text-decoration: none; font-size: 14px; }