body {
  margin: 0;
  font-family: Arial, sans-serif;
  color: #202124;
  background: #ffffff;
  line-height: 1.62;
}
.article {
  max-width: 920px;
  margin: 0 auto;
  padding: 40px 24px 72px;
}
h1 {
  font-size: 36px;
  line-height: 1.18;
  margin: 0 0 24px;
}
h2 {
  font-size: 22px;
  margin: 34px 0 12px;
}
p {
  margin: 0 0 16px;
}
ul {
  margin: 0 0 18px 22px;
  padding: 0;
}
li {
  margin: 0 0 8px;
}
.source {
  padding: 14px 16px;
  background: #f3f6f8;
  border-left: 4px solid #214f7a;
}
a {
  color: #214f7a;
}
code {
  font-family: Consolas, monospace;
  font-size: 0.94em;
  background: #f5f5f5;
  padding: 1px 4px;
}
@media (max-width: 640px) {
  .article { padding: 28px 18px 56px; }
  h1 { font-size: 28px; }
  h2 { font-size: 20px; }
}