:root {
  --text: #111;
  --text-secondary: #666;
  --bg: #fff;
  --border: #eee;
  --link: #111;
  --font: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

[data-theme="dark"] {
  --text: #e0e0e0;
  --text-secondary: #888;
  --bg: #111;
  --border: #222;
  --link: #e0e0e0;
}

*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  font-size: 15px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

/* --- Site Header --- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  max-width: 600px;
  margin: 0 auto;
  padding: 0.875rem 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-weight: 600;
  font-size: 0.9375rem;
  color: var(--text);
  text-decoration: none;
}

.header-nav {
  display: flex;
  gap: 1.25rem;
}

.header-nav a {
  font-size: 0.8125rem;
  color: var(--text-secondary);
  text-decoration: none;
}

.header-nav a:hover {
  color: var(--text);
  opacity: 1;
}

.lang-toggle {
  background: none;
  border: 1px solid var(--border);
  color: var(--text-secondary);
  font-family: var(--font);
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.04em;
  padding: 0.25rem 0.5rem;
  border-radius: 4px;
  cursor: pointer;
}

.lang-toggle:hover {
  color: var(--text);
  border-color: var(--text-secondary);
}

main {
  max-width: 600px;
  margin: 0 auto;
  padding: 4rem 1.5rem 6rem;
}

a {
  color: var(--link);
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

a:hover {
  opacity: 0.6;
}

/* --- Page Header --- */
main > header {
  margin-bottom: 4rem;
}

h1 {
  font-size: 1.125rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  margin-bottom: 0.75rem;
}

.intro {
  color: var(--text-secondary);
  font-size: 0.9375rem;
  line-height: 1.7;
  max-width: 480px;
}

/* --- Sections --- */
section {
  margin-bottom: 3rem;
}

h2 {
  font-size: 0.75rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

ul {
  list-style: none;
}

li {
  padding: 0.5rem 0;
  border-bottom: 1px solid var(--border);
  font-size: 0.9375rem;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 0 0.75rem;
}

li:last-child {
  border-bottom: none;
}

li > a,
li > span:first-child {
  font-weight: 500;
}

li p {
  width: 100%;
  font-size: 0.8125rem;
  color: var(--text-secondary);
  line-height: 1.5;
  margin-top: 0.125rem;
}

.meta {
  font-size: 0.75rem;
  color: var(--text-secondary);
  font-weight: 400;
  margin-left: auto;
}

/* --- Footer --- */
.site-footer {
  border-top: 1px solid var(--border);
}

.footer-inner {
  max-width: 600px;
  margin: 0 auto;
  padding: 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.8125rem;
  color: var(--text-secondary);
}

.footer-nav {
  display: flex;
  gap: 1rem;
}

.footer-nav a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.8125rem;
}

.footer-nav a:hover {
  color: var(--text);
  opacity: 1;
}

/* --- Responsive --- */
@media (max-width: 600px) {
  main {
    padding: 3rem 1.25rem 4rem;
  }

  main > header {
    margin-bottom: 3rem;
  }

  .header-nav {
    display: none;
  }

  .footer-inner {
    flex-direction: column;
    gap: 0.75rem;
    align-items: flex-start;
  }
}