:root {
  --primary: #2086a2;
  --primary-dark: #055a7b;
  --highlight: #56b5d3;
  --background: #ffffff;
  --surface: #f5f5f5;
  --ink: #151515;
  --muted: #5c5c5c;
  --outline: #e0e0e0;
  --max-width: 720px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --background: #151515;
    --surface: #1e1e1e;
    --ink: #e6e6e6;
    --muted: #b3b3b3;
    --outline: #3d3d3d;
  }
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: 1rem;
  line-height: 1.65;
  color: var(--ink);
  background: var(--background);
}

header {
  background: linear-gradient(135deg, var(--primary-dark), var(--primary));
  color: #fff;
  padding: 2.5rem 1.5rem 1.5rem;
  text-align: center;
}

header h1 {
  margin: 0 0 0.5rem;
  font-size: clamp(1.75rem, 4vw, 2.25rem);
  font-weight: 700;
  letter-spacing: -0.02em;
}

header .subtitle {
  margin: 0 auto;
  max-width: 36rem;
  opacity: 0.92;
  font-size: 0.95rem;
}

.lang-switcher {
  display: inline-flex;
  gap: 0.35rem;
  margin-top: 1.25rem;
  padding: 0.25rem;
  background: rgba(255, 255, 255, 0.12);
  border-radius: 999px;
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.lang-switcher button {
  appearance: none;
  border: none;
  background: transparent;
  color: rgba(255, 255, 255, 0.85);
  font: inherit;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  padding: 0.45rem 0.85rem;
  border-radius: 999px;
  cursor: pointer;
  transition: background 0.15s, color 0.15s;
}

.lang-switcher button:hover {
  background: rgba(255, 255, 255, 0.12);
  color: #fff;
}

.lang-switcher button[aria-pressed="true"] {
  background: #fff;
  color: var(--primary-dark);
}

main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 2rem 1.5rem 3rem;
}

.lang-content[hidden] {
  display: none;
}

.meta {
  font-size: 0.875rem;
  color: var(--muted);
  margin-bottom: 2rem;
  padding-bottom: 1.25rem;
  border-bottom: 1px solid var(--outline);
}

section {
  margin-bottom: 2rem;
}

h2 {
  font-size: 1.2rem;
  color: var(--primary-dark);
  margin: 0 0 0.75rem;
  line-height: 1.35;
}

@media (prefers-color-scheme: dark) {
  h2 {
    color: var(--highlight);
  }
}

h3 {
  font-size: 1rem;
  margin: 1rem 0 0.5rem;
  color: var(--ink);
}

p, li {
  color: var(--ink);
}

ul, ol {
  padding-left: 1.35rem;
  margin: 0.5rem 0 0;
}

li + li {
  margin-top: 0.35rem;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
  margin-top: 0.75rem;
}

th, td {
  border: 1px solid var(--outline);
  padding: 0.6rem 0.75rem;
  text-align: left;
  vertical-align: top;
}

th {
  background: var(--surface);
  font-weight: 600;
}

a {
  color: var(--primary);
  text-decoration-thickness: 1px;
  text-underline-offset: 2px;
}

a:hover {
  color: var(--primary-dark);
}

footer {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1.5rem;
  border-top: 1px solid var(--outline);
  font-size: 0.875rem;
  color: var(--muted);
  text-align: center;
}

.notice {
  background: var(--surface);
  border: 1px solid var(--outline);
  border-radius: 12px;
  padding: 1rem 1.15rem;
  font-size: 0.9rem;
  color: var(--muted);
  margin-bottom: 2rem;
}