body {
  max-width: 560px;
  margin: 0 auto;
  padding: 24px 16px;
  font: 14px -apple-system, system-ui, sans-serif;
  color: #1a1a1a;
  background: #fff;
}

h1 { margin: 0 0 16px; }

section {
  margin-bottom: 28px;
  padding-bottom: 20px;
  border-bottom: 1px solid #eee;
}
section:last-of-type { border-bottom: none; }

h2 {
  font-size: 15px;
  margin: 0 0 10px;
}

label {
  display: block;
  margin: 8px 0;
  font-weight: 600;
  font-size: 13px;
}

select, input, textarea {
  display: block;
  margin-top: 4px;
  font: inherit;
  padding: 5px 7px;
  width: 100%;
  max-width: 320px;
  box-sizing: border-box;
}

button {
  font: inherit;
  padding: 6px 12px;
  margin-top: 8px;
  margin-right: 8px;
}

#rules-locked {
  color: #888;
  font-style: italic;
}

#pair-message {
  min-height: 1.2em;
  color: #555;
}