:root {
  color-scheme: light;
  --bg: #f7f8fb;
  --card: #ffffff;
  --text: #1a1c20;
  --muted: #5f6b7a;
  --primary: #4f46e5;
  --primary-dark: #4338ca;
  --border: #e5e7eb;
  --shadow: 0 10px 30px rgba(15, 23, 42, 0.08);
  --radius: 16px;
  --max: 1100px;
  font-family: "Inter", "Noto Sans JP", "Noto Sans", system-ui, -apple-system, sans-serif;
}

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

body {
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
}

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

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


main {
  max-width: var(--max);
  margin: 40px auto 0 auto;
  padding: 40px 20px 80px;
  background: var(--card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-start;
}

h1, h2, h3 {
  margin-bottom: 16px;
  text-align: center;
}

nav ul {
  display: flex;
  gap: 16px;
  list-style: none;
  padding-left: 0;
  justify-content: center;
  margin-bottom: 32px;
}

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

a.button {
  display: inline-block;
  background: var(--primary);
  color: #fff;
  padding: 8px 20px;
  border-radius: 8px;
  margin-top: 24px;
  text-align: center;
  transition: background 0.2s;
}
a.button:hover {
  background: var(--primary-dark);
}

footer {
  margin: 40px 0 0 0;
  color: var(--muted);
  font-size: 0.95em;
  text-align: center;
}

h1, h2, h3 {
  margin-bottom: 16px;
}

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

nav ul {
  display: flex;
  gap: 16px;
  list-style: none;
  padding-left: 0;
}

@media (max-width: 600px) {
  main {
    padding: 20px 8px 40px;
  }
  nav ul {
    flex-direction: column;
    gap: 8px;
  }
}