body {
  margin: 0;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
  padding: 1rem;
}

header {
  text-align: center;
  margin-bottom: 1rem;
}

main {
  max-width: 500px;
  margin: 0 auto;
}

.hidden {
  display: none;
}

label {
  display: block;
  margin-bottom: 0.5rem;
}

input {
  width: 100%;
  padding: 0.5rem;
  margin-top: 0.2rem;
  box-sizing: border-box;
}

button {
  padding: 0.6rem 1rem;
  margin-top: 0.8rem;
  border-radius: 6px;
  border: none;
  cursor: pointer;
}

button.secondary {
  background: #eee;
}

button:not(.secondary) {
  background: #0070f3;
  color: white;
}

.error {
  color: red;
  min-height: 1.2em;
}

#preview {
  width: 100%;
  margin-top: 1rem;
}