:root {
  color-scheme: light dark;
  --bg: #f5f7fb;
  --surface: rgba(255, 255, 255, 0.92);
  --surface-border: rgba(15, 23, 42, 0.08);
  --text: #0f172a;
  --muted: #475569;
  --accent: #0f766e;
  --accent-soft: rgba(15, 118, 110, 0.1);
  --shadow: 0 12px 40px rgba(15, 23, 42, 0.08);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b1120;
    --surface: rgba(15, 23, 42, 0.9);
    --surface-border: rgba(148, 163, 184, 0.18);
    --text: #e5eefb;
    --muted: #94a3b8;
    --accent: #2dd4bf;
    --accent-soft: rgba(45, 212, 191, 0.14);
    --shadow: 0 18px 48px rgba(2, 6, 23, 0.4);
  }
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text);
}

body {
  min-height: 100vh;
  padding: 32px 20px 48px;
}

.shell {
  max-width: 920px;
  margin: 0 auto;
}

.nav {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: center;
}

.topbar {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
}

.nav a {
  color: var(--muted);
  text-decoration: none;
  padding: 8px 12px;
  border-radius: 8px;
  background: var(--surface);
  border: 1px solid var(--surface-border);
}

.nav a.active {
  color: var(--accent);
  background: var(--accent-soft);
  border-color: transparent;
}

.language-switch {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 4px;
  border-radius: 8px;
  background: var(--surface);
  border: 1px solid var(--surface-border);
  box-shadow: var(--shadow);
}

.language-switch button {
  appearance: none;
  border: 0;
  background: transparent;
  color: var(--muted);
  border-radius: 6px;
  padding: 8px 12px;
  font: inherit;
  cursor: pointer;
}

.language-switch button.active {
  color: var(--accent);
  background: var(--accent-soft);
}

.card {
  background: var(--surface);
  border: 1px solid var(--surface-border);
  border-radius: 8px;
  box-shadow: var(--shadow);
  padding: 28px;
}

.hero {
  margin-bottom: 20px;
}

.eyebrow {
  color: var(--accent);
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 8px;
}

h1,
h2,
h3 {
  margin: 0 0 12px;
  line-height: 1.2;
}

h1 {
  font-size: 30px;
}

h2 {
  font-size: 20px;
  margin-top: 28px;
}

h3 {
  font-size: 16px;
  margin-top: 20px;
}

p,
li {
  color: var(--muted);
  line-height: 1.65;
}

ul,
ol {
  margin: 12px 0;
  padding-left: 20px;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 16px;
}

.panel {
  padding: 18px;
  border-radius: 8px;
  border: 1px solid var(--surface-border);
  background: rgba(255, 255, 255, 0.35);
}

@media (prefers-color-scheme: dark) {
  .panel {
    background: rgba(15, 23, 42, 0.45);
  }
}

.footer {
  margin-top: 20px;
  font-size: 13px;
  color: var(--muted);
}

a {
  color: var(--accent);
}