:root {
  --bg: #eef4ff;
  --surface: rgba(255, 255, 255, 0.9);
  --text: #0f1728;
  --muted: #5f6b80;
  --line: rgba(126, 156, 208, 0.28);
  --primary-a: #3d6eff;
  --primary-b: #00b7ff;
  --shadow: 0 18px 44px rgba(27, 46, 89, 0.1);
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'Segoe UI', sans-serif;
  color: var(--text);
  background:
    radial-gradient(1200px 600px at 18% -10%, rgba(89, 142, 255, 0.22), transparent 64%),
    radial-gradient(900px 560px at 94% 2%, rgba(112, 233, 255, 0.18), transparent 62%),
    linear-gradient(180deg, #f9fbff 0%, var(--bg) 100%);
}

.page {
  width: min(960px, calc(100vw - 1.6rem));
  margin: 1rem auto 2rem;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: var(--surface);
  box-shadow: var(--shadow);
  padding: 1rem;
}

.top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 0.6rem;
  flex-wrap: wrap;
  border-bottom: 1px solid var(--line);
  padding-bottom: 0.6rem;
}

.brand {
  margin: 0;
  font-size: 0.92rem;
  font-weight: 700;
}

.back-link {
  text-decoration: none;
  color: #2e5bd2;
  font-size: 0.84rem;
}

h1,
h2,
p,
ul {
  margin: 0;
}

h1 {
  margin-top: 0.85rem;
  font-size: clamp(1.6rem, 4vw, 2.1rem);
  line-height: 1.08;
}

.subtitle {
  margin-top: 0.5rem;
  color: var(--muted);
  font-size: 0.9rem;
  line-height: 1.55;
}

.section {
  margin-top: 0.95rem;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: #fff;
  padding: 0.8rem;
}

.section h2 {
  font-size: 1.02rem;
}

.section p,
.section ul {
  margin-top: 0.45rem;
  color: #3f4c61;
  font-size: 0.9rem;
  line-height: 1.62;
}

.section ul {
  padding-left: 1rem;
}

.footer-note {
  margin-top: 0.9rem;
  color: var(--muted);
  font-size: 0.82rem;
}