body {
  margin: 0;
  font-family: "Inter", system-ui, sans-serif;
  background: linear-gradient(135deg, #0f172a, #1e293b);
  color: #e2e8f0;
  display: flex;
  justify-content: center;
  padding: 30px;
}

.container {
  width: 100%;
  max-width: 700px;
}

.title {
  text-align: center;
  font-size: 32px;
  margin-bottom: 6px;
}

.subtitle {
  text-align: center;
  color: #94a3b8;
  margin-bottom: 20px;
}

.card {
  background: rgba(255, 255, 255, 0.06);
  padding: 20px;
  border-radius: 14px;
  margin-bottom: 20px;
  backdrop-filter: blur(12px);
  border: 1px solid rgba(255, 255, 255, 0.1);
  box-shadow: 0 8px 20px rgba(0,0,0,0.25);
}

.card h2 {
  margin-top: 0;
  margin-bottom: 12px;
  font-size: 20px;
}

.options {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
  margin-bottom: 15px;
}

.length-control {
  display: flex;
  align-items: center;
  gap: 10px;
}

.length-control input[type="number"] {
  width: 60px;
  padding: 6px;
  border-radius: 6px;
  border: none;
  background: #0f172a;
  color: #e2e8f0;
}

.btn {
  width: 100%;
  padding: 12px;
  background: #3b82f6;
  border: none;
  border-radius: 8px;
  color: white;
  font-size: 16px;
  cursor: pointer;
  margin-top: 10px;
  transition: 0.2s;
}

.btn:hover {
  background: #60a5fa;
}

.results {
  list-style: none;
  padding: 0;
  margin: 0;
}

.results li {
  background: rgba(255,255,255,0.08);
  padding: 12px;
  border-radius: 8px;
  margin-bottom: 8px;
  font-family: monospace;
  cursor: pointer;
  transition: 0.15s;
  display: flex;
  justify-content: space-between;
}

.results li:hover {
  background: rgba(255,255,255,0.15);
}

.results li.copied {
  background: #22c55e !important;
  color: #0f172a;
}

.error {
  color: #f87171;
  font-size: 14px;
  min-height: 18px;
}