:root {
  --blue: #2962ff;
  --blue-dark: #1d4fd9;
  --bg: #f5f6f8;
  --panel: #f4f7fb;
  --text: #1f2330;
  --muted: #4a5060;
  --border: #d8dde6;
  --card: #ffffff;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.55;
}

main.card {
  max-width: 820px;
  margin: 32px auto;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 40px 48px;
  box-shadow: 0 1px 2px rgba(0,0,0,0.04);
}

article { max-width: 100%; }

h1 {
  color: var(--blue);
  font-size: 2.25rem;
  font-weight: 800;
  margin: 0 0 24px 0;
  letter-spacing: -0.01em;
}

h2 {
  color: var(--blue);
  font-size: 1.4rem;
  font-weight: 700;
  margin: 32px 0 14px 0;
  letter-spacing: -0.005em;
}

p {
  margin: 0 0 14px 0;
  color: var(--text);
}

blockquote.summary {
  margin: 0 0 28px 0;
  padding: 18px 22px;
  background: var(--panel);
  border-left: 4px solid var(--border);
  color: var(--muted);
  font-style: italic;
  border-radius: 4px;
  font-size: 0.98rem;
}

ul.link-list {
  list-style: disc;
  padding-left: 22px;
  margin: 0 0 12px 0;
}

ul.link-list li { margin-bottom: 6px; }

section.panel {
  background: var(--panel);
  border-radius: 10px;
  padding: 22px 26px;
  margin: 24px 0;
}

section.panel h2 {
  margin-top: 0;
}

ul.arrow-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

ul.arrow-list li {
  padding-left: 28px;
  position: relative;
  margin-bottom: 14px;
  color: var(--text);
}

ul.arrow-list li::before {
  content: "→";
  color: var(--blue);
  position: absolute;
  left: 4px;
  top: 0;
  font-weight: 700;
}

ul.arrow-list li strong {
  color: var(--blue);
  font-weight: 700;
}

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

a:hover {
  text-decoration: underline;
  color: var(--blue-dark);
}

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

@media (max-width: 640px) {
  main.card { margin: 0; border-radius: 0; padding: 24px 20px; border: none; }
  h1 { font-size: 1.8rem; }
  h2 { font-size: 1.2rem; }
  section.panel { padding: 18px; }
}