* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  background: #f6f7f8;
  color: #1a1a1a;
  line-height: 1.5;
}
header {
  background: #1a1a1a;
  color: #fff;
  padding: 14px 24px;
  display: flex;
  gap: 12px;
  align-items: baseline;
}
header .brand {
  color: #fff;
  text-decoration: none;
  font-weight: 700;
  font-size: 18px;
}
header .sub {
  color: #999;
  font-size: 13px;
}
main {
  max-width: 880px;
  margin: 24px auto;
  padding: 0 16px;
}
footer {
  text-align: center;
  padding: 24px;
  color: #888;
  font-size: 13px;
}
footer a { color: #555; }
.card {
  background: #fff;
  padding: 28px;
  border-radius: 10px;
  box-shadow: 0 1px 3px rgba(0,0,0,.05);
}
.card.narrow { max-width: 380px; margin: 60px auto; }
h1 { margin-top: 0; }
h2 {
  margin-top: 32px;
  padding-top: 16px;
  border-top: 1px solid #eee;
  font-size: 18px;
}
.muted { color: #777; font-size: 14px; }
label {
  display: block;
  margin: 14px 0;
  font-size: 14px;
  color: #444;
}
input[type=text], input[type=password], input[type=number], input[type=url], textarea {
  display: block;
  width: 100%;
  margin-top: 4px;
  padding: 9px 11px;
  border: 1px solid #ccc;
  border-radius: 6px;
  font-size: 14px;
  font-family: inherit;
}
textarea { resize: vertical; font-family: ui-monospace, monospace; font-size: 13px; }
button {
  background: #1a73e8;
  color: #fff;
  border: 0;
  padding: 9px 16px;
  border-radius: 6px;
  cursor: pointer;
  font-size: 14px;
}
button:hover { background: #1557b0; }
button.primary {
  display: block;
  margin: 24px auto 0;
  font-size: 16px;
  padding: 12px 28px;
}
.error {
  background: #fee;
  color: #900;
  padding: 10px 14px;
  border-radius: 6px;
  margin: 12px 0;
}
.errors {
  background: #fff8e1;
  border-left: 4px solid #f9a825;
  padding: 12px 16px;
  margin: 16px 0;
  border-radius: 4px;
}
.errors h3 { margin: 0 0 8px; font-size: 15px; }
.errors ul { margin: 6px 0; padding-left: 20px; }
.errors code { background: #f5deb3; padding: 1px 5px; border-radius: 3px; font-size: 12px; }
.ok {
  background: #e8f5e9;
  border-left: 4px solid #43a047;
  padding: 10px 14px;
  border-radius: 4px;
  margin: 16px 0;
}
.copybox { position: relative; margin: 8px 0 20px; }
.copybox button { margin-bottom: 6px; margin-right: 6px; }
.checklist {
  list-style: none;
  padding: 0;
  margin: 12px 0;
}
.checklist li {
  padding: 8px 0;
  border-bottom: 1px solid #f0f0f0;
}
.checklist input[type=checkbox] { margin-right: 10px; }