body {
  font-family: -apple-system, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  line-height: 1.7;
  color: #222;
  max-width: 720px;
  margin: 0 auto;
  padding: 24px;
}

h1 { font-size: 1.5em; margin: 0.2em 0 0.4em; }
h2 { font-size: 1.12em; margin-top: 1.8em; }
p { margin: 0.6em 0; }
a { color: #1a73e8; }
.tagline { color: #666; margin: 0.2em 0 1.4em; }
.lang-switch { display: flex; align-items: center; justify-content: flex-end; gap: 10px; margin: 0 0 2em; }
.lang-switch label { color: #666; font-size: 0.9em; white-space: nowrap; }
.lang-switch select { min-width: 168px; max-width: 100%; padding: 9px 34px 9px 12px; border: 1px solid #c8c8c8; border-radius: 10px; background-color: #fff; color: #222; font: inherit; cursor: pointer; }
.lang-switch select:hover { border-color: #888; }
.lang-switch select:focus-visible { outline: 3px solid rgba(26, 115, 232, 0.22); border-color: #1a73e8; }
.lang-panel { display: none; }
.lang-panel.active { display: block; }

details { border-bottom: 1px solid #ececec; padding: 0.4em 0; }
summary { cursor: pointer; font-weight: 600; }
summary::marker { color: #888; }
summary:focus-visible { outline: 3px solid rgba(26, 115, 232, 0.22); border-radius: 4px; }
details p { color: #444; margin: 0.4em 0 0.8em; }
.contact { background: #f7f8f7; border: 1px solid #e3e7e2; border-radius: 10px; padding: 14px 18px; }
.contact a { color: #2b6a44; text-decoration: none; font-weight: 600; }
.contact a:hover { text-decoration: underline; }
.legal { margin-top: 2.25em; padding-top: 1.25em; border-top: 1px solid #ececec; font-size: 0.85em; color: #666; }
.legal-links { display: flex; flex-wrap: wrap; align-items: center; gap: 0.35em 0.75em; }
.legal-links a { color: #58606b; text-decoration: none; font-weight: 600; }
.legal-links a:hover { color: #2b6a44; text-decoration: underline; }
.legal-links a:focus-visible { outline: 3px solid rgba(26, 115, 232, 0.22); outline-offset: 3px; border-radius: 3px; }
.legal-separator { color: #b2b7bd; }
.legal-copyright { margin: 0.45em 0 0; }

@media (max-width: 480px) {
  body { padding: 18px; }
  .lang-switch { justify-content: space-between; }
  .lang-switch select { width: min(210px, 66vw); min-width: 0; }
}

@media (prefers-color-scheme: dark) {
  body { background: #1c1c1e; color: #eee; }
  .tagline, .lang-switch label, .legal { color: #aaa; }
  .lang-switch select { background-color: #2c2c2e; border-color: #4a4a4d; color: #eee; }
  .lang-switch select:hover { border-color: #8e8e93; }
  details { border-bottom-color: #3a3a3c; }
  details p, summary { color: #d6d6d6; }
  summary::marker { color: #8e8e93; }
  .contact { background: #2c2c2e; border-color: #3a3a3c; }
  .contact a { color: #7ec89a; }
  a { color: #8ab4f8; }
  .legal { border-top-color: #3a3a3c; }
  .legal-links a { color: #b8bdc5; }
  .legal-links a:hover { color: #7ec89a; }
  .legal-separator { color: #63666b; }
}