:root { color-scheme: dark; }
body {
  margin: 0; padding: 1.5rem; font-family: system-ui, sans-serif;
  background: #0f172a; color: #e2e8f0; min-height: 100vh;
}
h1, h2 { font-weight: 600; }
button {
  background: #2563eb; color: white; border: none; border-radius: 8px;
  padding: 0.75rem 1rem; font-size: 1rem; margin: 0.5rem 0; cursor: pointer;
}
button:disabled { background: #334155; cursor: not-allowed; }
input {
  display: block; width: 100%; box-sizing: border-box; padding: 0.75rem;
  border-radius: 8px; border: 1px solid #334155; background: #1e293b;
  color: #e2e8f0; font-size: 1.1rem; margin: 0.5rem 0;
}
ul { list-style: none; padding: 0; }
li {
  display: flex; align-items: center; justify-content: space-between;
  background: #1e293b; padding: 0.75rem 1rem; border-radius: 8px; margin-bottom: 0.5rem;
}
.error { color: #f87171; }
header { display: flex; justify-content: space-between; align-items: center; }