*,
*::before,
*::after {
  box-sizing: border-box;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'SF Pro Text', Roboto, Helvetica, Arial, sans-serif;
  margin: 0;
  background: #f6f8fa;
  color: #1b1f23;
}

a {
  color: #0969da;
}

header {
  background: #f6f8fa;
  padding: 20px;
  color: #24292e;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand img {
  width: 40px;
  height: 40px;
  border-radius: 6px;
}

header h1 {
  margin: 0;
  font-size: 20px;
}

.header-right {
  display: flex;
  align-items: center;
  gap: 12px;
}

.button-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: center;
  margin: 22px 0 26px;
}

.btn {
  display: inline-flex;
  align-items: center;
  height: 40px;
  padding: 0 16px;
  border-radius: 8px;
  text-decoration: none;
  font-weight: 600;
}

.btn.primary {
  background: #007aff;
  color: #fff;
}

.btn.secondary {
  background: #f2f2f2;
  color: #111;
  border: 1px solid #d0d7de;
}

.guide-shell {
  max-width: 1120px;
  margin: 0 auto;
  padding: 30px 30px 56px;
}

.eyebrow {
  color: #57606a;
  font-weight: 700;
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: .06em;
}

h1 {
  max-width: 900px;
  font-size: clamp(32px, 4vw, 48px);
  line-height: 1.08;
  margin: 10px 0 14px;
  letter-spacing: 0;
}

h2 {
  max-width: 860px;
  margin-top: 38px;
  font-size: 25px;
}

p,
li {
  line-height: 1.68;
}

.lede {
  max-width: 860px;
  font-size: 19px;
  color: #3d444d;
}

.guide-shell > p,
.guide-shell > ul:not(.sources),
.guide-shell > pre {
  max-width: 860px;
}

.hero-image {
  display: block;
  width: 100%;
  margin: 30px 0 34px;
}

.note,
.boundary {
  margin: 18px 0;
  padding: 14px 16px;
  background: #fff;
  border: 1px solid #d0d7de;
  border-left: 4px solid #0969da;
  border-radius: 8px;
}

.boundary {
  border-left-color: #bf8700;
}

.meta-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 12px;
  margin: 22px 0;
}

.meta-card {
  padding: 14px 16px;
  background: #fff;
  border: 1px solid #d0d7de;
  border-radius: 8px;
}

.meta-card strong {
  display: block;
  margin-bottom: 6px;
}

code,
pre {
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
}

pre {
  background: #fff;
  border: 1px solid #d0d7de;
  border-radius: 8px;
  padding: 14px;
  overflow: auto;
}

.sources {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 10px;
  padding-left: 0;
  list-style: none;
}

.sources li {
  background: #fff;
  border: 1px solid #d0d7de;
  border-radius: 8px;
  padding: 12px 14px;
}

.site-footer {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 30px 36px;
  color: #57606a;
  font-size: 14px;
}

@media (max-width: 720px) {
  header {
    align-items: flex-start;
    flex-direction: column;
  }

  .header-right {
    justify-content: flex-start;
  }

  .guide-shell {
    padding: 24px 18px 48px;
  }
}