* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: Segoe UI, sans-serif;
  background: linear-gradient(180deg, #f4f7ff 0%, #eef9f3 100%);
  color: #1f2937;
}

header {
  padding: 24px;
  border-bottom: 1px solid #dbe3ef;
  background: #ffffffcc;
  backdrop-filter: blur(6px);
}

h1 {
  margin: 0;
  font-size: 24px;
}

main {
  padding: 24px;
  display: grid;
  gap: 16px;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.card {
  background: white;
  border: 1px solid #d8e2f1;
  border-radius: 12px;
  padding: 16px;
  box-shadow: 0 6px 20px rgba(20, 40, 80, 0.08);
}

button {
  padding: 10px 14px;
  border-radius: 8px;
  border: 0;
  background: #1d4ed8;
  color: white;
  cursor: pointer;
}

button:hover {
  background: #1e40af;
}

pre {
  white-space: pre-wrap;
  background: #f8fafc;
  border-radius: 8px;
  padding: 12px;
}