:root {
  color-scheme: light dark;
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
}

body {
  margin: 0;
  display: flex;
  justify-content: center;
  background: #242527;
}

.app {
  width: 100%;
  max-width: 640px;
  padding: 1.5rem;
}

header h1 {
  margin-bottom: 0.5rem;
}

nav {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
}

nav button {
  padding: 0.5rem 1rem;
  border: 1px solid #ccc;
  background: white;
  border-radius: 6px;
  cursor: pointer;
}

nav button.active {
  background: #2d6cdf;
  color: white;
  border-color: #2d6cdf;
}

.question {
  background: #343537;
  border-radius: 8px;
  padding: 1rem 1.25rem;
  margin-bottom: 1.25rem;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
}

form {
  display: flex;
  flex-direction: column;
  gap: 0.9rem;
  background: #343537;
  padding: 1.25rem;
  border-radius: 8px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
}

label {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  font-size: 0.9rem;
  color: #ccc;
}

input {
  padding: 0.5rem 0.6rem;
  border: 1px solid #ccc;
  border-radius: 6px;
  font-size: 1rem;
}

button {
  padding: 0.6rem;
  border: none;
  border-radius: 6px;
  background: #2d6cdf;
  color: white;
  font-size: 1rem;
  cursor: pointer;
}

.today {
  color: #666;
  margin-top: 0;
}

.success {
  margin-top: 1rem;
  padding: 1rem;
  background: #b7f6b9;
  border: 1px solid #9fd6a8;
  border-radius: 8px;
  color: #1f7a1f;
}

.error {
  margin-top: 1rem;
  padding: 0.75rem 1rem;
  background: #fbe9e9;
  border: 1px solid #e3a3a3;
  border-radius: 8px;
  color: #7a1f1f;
}

.completion-code {
  display: block;
  word-break: break-all;
  padding: 0.5rem;
  border-radius: 6px;
  font-size: 0.8rem;
}