:root {
  --bg: #fafcff;
  --surface: #ffffff;
  --text: #2d3748;
  --text-muted: #718096;
  --heading: #1a202c;
  --accent: #4a90f8;
  --accent-hover: #2f78e4;
  --border: #e2e8f0;
  --card-shadow: 0 4px 24px rgba(74, 144, 248, 0.08);
}

* {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  padding: 24px 16px 64px;
  background: linear-gradient(180deg, #eaf3ff 0%, var(--bg) 320px);
  background-attachment: fixed;
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans",
    "Hiragino Kaku Gothic ProN", "Yu Gothic", Meiryo, sans-serif;
  font-size: 16px;
  line-height: 1.75;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
}

main {
  max-width: 720px;
  margin: 0 auto;
}

header {
  text-align: center;
  padding: 32px 0 24px;
}

header .icon {
  font-size: 56px;
  line-height: 1;
}

header h1 {
  margin: 12px 0 4px;
  color: var(--heading);
  font-size: 28px;
  font-weight: 700;
  letter-spacing: 0.02em;
}

header p {
  margin: 0;
  color: var(--text-muted);
  font-size: 14px;
}

article {
  background: var(--surface);
  border-radius: 20px;
  padding: 32px 28px;
  box-shadow: var(--card-shadow);
}

article h2 {
  margin: 32px 0 12px;
  color: var(--heading);
  font-size: 18px;
  font-weight: 700;
  border-left: 3px solid var(--accent);
  padding-left: 12px;
}

article h2:first-of-type {
  margin-top: 0;
}

article p,
article ul {
  margin: 0 0 12px;
}

article ul {
  padding-left: 22px;
}

article li {
  margin-bottom: 4px;
}

article a {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid rgba(74, 144, 248, 0.3);
  transition: border-color 0.2s, color 0.2s;
}

article a:hover {
  color: var(--accent-hover);
  border-bottom-color: var(--accent-hover);
}

.meta {
  margin: 0 0 24px;
  padding: 12px 16px;
  background: #f4f8ff;
  border-radius: 12px;
  color: var(--text-muted);
  font-size: 14px;
}

.signature {
  margin-top: 32px;
  padding-top: 16px;
  border-top: 1px solid var(--border);
  color: var(--text-muted);
  font-size: 14px;
  text-align: right;
}

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px;
  margin-top: 24px;
}

.card {
  display: block;
  padding: 24px 20px;
  background: var(--surface);
  border-radius: 16px;
  box-shadow: var(--card-shadow);
  color: var(--text);
  text-decoration: none;
  transition: transform 0.15s, box-shadow 0.15s;
}

.card:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 28px rgba(74, 144, 248, 0.16);
}

.card .card-title {
  margin: 0 0 6px;
  color: var(--heading);
  font-size: 16px;
  font-weight: 700;
}

.card .card-desc {
  margin: 0;
  color: var(--text-muted);
  font-size: 13px;
  line-height: 1.6;
}

footer {
  margin-top: 32px;
  text-align: center;
  color: var(--text-muted);
  font-size: 12px;
}

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

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

@media (max-width: 480px) {
  body {
    padding: 16px 12px 48px;
  }

  article {
    padding: 24px 20px;
  }

  header h1 {
    font-size: 24px;
  }
}