:root {
  color-scheme: light dark;
  --bg: #faf8ff;
  --surface: #ffffff;
  --text: #1c1a22;
  --muted: #5d5868;
  --border: #e3dfeb;
  --accent: #5e35b1;
  --accent-text: #ffffff;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #141218;
    --surface: #1d1b22;
    --text: #e8e3ef;
    --muted: #a59fb0;
    --border: #322e3a;
    --accent: #b39ddb;
    --accent-text: #1d1028;
  }
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.6 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

main,
header,
footer {
  max-width: 720px;
  margin: 0 auto;
  padding: 0 16px;
}

header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding-top: 20px;
  padding-bottom: 20px;
}

.logo {
  font-weight: 800;
  font-size: 1.25rem;
  color: var(--accent);
  text-decoration: none;
}

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

h1 {
  font-size: 2rem;
  line-height: 1.2;
  margin: 24px 0 8px;
}

h2 {
  font-size: 1.25rem;
  margin: 40px 0 8px;
}

h3 {
  font-size: 1.05rem;
  margin: 24px 0 4px;
}

.muted {
  color: var(--muted);
}

table {
  width: 100%;
  border-collapse: collapse;
  margin: 16px 0;
  font-size: 0.95rem;
}

th,
td {
  text-align: left;
  vertical-align: top;
  padding: 8px;
  border-bottom: 1px solid var(--border);
}

.table-wrap {
  overflow-x: auto;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px 20px;
  margin: 16px 0;
}

.hero {
  text-align: center;
  padding: 64px 0 32px;
}

.hero h1 {
  font-size: 3rem;
  margin: 0;
  color: var(--accent);
}

.hero p {
  font-size: 1.2rem;
}

.equation {
  font-size: 1.75rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  margin: 32px 0;
}

.button {
  display: inline-block;
  background: var(--accent);
  color: var(--accent-text);
  text-decoration: none;
  font-weight: 600;
  padding: 12px 24px;
  border-radius: 999px;
}

footer {
  margin-top: 64px;
  padding-top: 24px;
  padding-bottom: 32px;
  border-top: 1px solid var(--border);
  font-size: 0.9rem;
  color: var(--muted);
}

footer nav {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
  margin-bottom: 8px;
}