:root {
  --ink: #1c1c1e;
  --muted: #5f5f69;
  --ground: #f5f5f8;
  --card: rgba(255, 255, 255, 0.72);
  --line: rgba(28, 28, 30, 0.1);
  --link: #3a57d6;
  color-scheme: light;
}

* {
  box-sizing: border-box;
}

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

body {
  margin: 0;
  min-height: 100vh;
  background: var(--ground);
  color: var(--ink);
  font: 16px/1.8 -apple-system, BlinkMacSystemFont, 'Hiragino Sans', 'Noto Sans JP', 'Segoe UI', system-ui, sans-serif;
  -webkit-font-smoothing: antialiased;
}

body::before {
  content: '';
  position: fixed;
  inset: 0;
  z-index: -1;
  background:
    radial-gradient(40rem 30rem at 10% 0%, #ffd6ea 0%, transparent 60%),
    radial-gradient(36rem 28rem at 100% 30%, #cfe6ff 0%, transparent 60%),
    radial-gradient(30rem 24rem at 30% 100%, #fff0c2 0%, transparent 60%);
  opacity: 0.8;
}

main {
  max-width: 720px;
  margin: 0 auto;
  padding: 32px 16px 64px;
}

header {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 28px;
}

header img {
  width: 56px;
  height: 56px;
  border-radius: 14px;
  box-shadow: 0 6px 18px rgba(28, 28, 50, 0.12);
}

header p {
  margin: 0;
  font-size: 20px;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.lang {
  margin-left: auto;
  font-size: 14px;
}

article {
  background: var(--card);
  border: 1px solid rgba(255, 255, 255, 0.9);
  border-radius: 24px;
  padding: 28px 24px;
  box-shadow: 0 10px 30px rgba(28, 28, 50, 0.08);
}

h1 {
  margin: 0 0 4px;
  font-size: 26px;
  line-height: 1.35;
}

h2 {
  margin: 32px 0 8px;
  padding-top: 20px;
  border-top: 1px solid var(--line);
  font-size: 18px;
}

.updated {
  margin: 0 0 20px;
  color: var(--muted);
  font-size: 14px;
}

ul {
  padding-left: 1.3em;
}

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

.links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 20px 0 0;
  padding: 0;
  list-style: none;
}

.links a {
  display: inline-block;
  padding: 10px 18px;
  border-radius: 999px;
  background: var(--ink);
  color: #fff;
  text-decoration: none;
  font-weight: 600;
  font-size: 15px;
}

footer {
  margin-top: 28px;
  color: var(--muted);
  font-size: 13px;
  text-align: center;
}

h3 {
  margin: 20px 0 4px;
  font-size: 16px;
}

h3 + p {
  margin-top: 0;
}