:root {
  --text-primary: #252233;
  --text-secondary: #7A7E85;
  --text-tertiary: #A0A4AB;
  --bg: #FDFDFE;
  --border: #ECEEF0;
  --link: #6C9BCF;
}

* {
  box-sizing: border-box;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

html, body {
  margin: 0;
  padding: 0;
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", system-ui, sans-serif;
  background: var(--bg);
  color: var(--text-primary);
  line-height: 1.6;
}

main {
  max-width: 720px;
  margin: 0 auto;
  padding: 64px 24px 96px;
}

.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 48px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border);
}

.logo {
  font-size: 18px;
  font-weight: 700;
  color: var(--text-primary);
  text-decoration: none;
  letter-spacing: -0.3px;
}

.lang-switch {
  font-size: 13px;
  color: var(--text-secondary);
}
.lang-switch a {
  color: var(--text-secondary);
  text-decoration: none;
  padding: 0 4px;
}
.lang-switch a.active {
  color: var(--text-primary);
  font-weight: 600;
}

h1 {
  font-size: 32px;
  line-height: 1.2;
  margin: 0 0 12px;
  letter-spacing: -0.5px;
}

.updated {
  font-size: 13px;
  color: var(--text-tertiary);
  margin: 0 0 40px;
}

h2 {
  font-size: 20px;
  margin: 40px 0 12px;
  letter-spacing: -0.2px;
}

h3 {
  font-size: 16px;
  margin: 24px 0 8px;
}

p, ul, ol {
  font-size: 15px;
  color: var(--text-primary);
  margin: 0 0 16px;
}

ul, ol {
  padding-left: 24px;
}

li {
  margin-bottom: 6px;
}

a {
  color: var(--link);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

strong {
  font-weight: 600;
}

footer {
  margin-top: 64px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
  font-size: 13px;
  color: var(--text-tertiary);
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}

footer a {
  color: var(--text-tertiary);
}

@media (max-width: 480px) {
  main {
    padding: 40px 20px 64px;
  }
  h1 {
    font-size: 26px;
  }
}