body {
  font-family: Arial, sans-serif;
  background: #f4f6f8;
  margin: 0;
}
header {
  background: #0b5;
  color: white;
  padding: 15px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
main {
  max-width: 900px;
  margin: 30px auto;
  background: white;
  padding: 20px;
  border-radius: 8px;
  box-shadow: 0 4px 10px rgba(0,0,0,0.1);
}
.btn {
  background: #0b5;
  color: white;
  border: none;
  border-radius: 6px;
  padding: 8px 14px;
  cursor: pointer;
}
.btn.danger {
  background: #d33;
}
table {
  width: 100%;
  border-collapse: collapse;
}
th, td {
  border-bottom: 1px solid #eee;
  padding: 8px;
}
a {
  color: #0b5;
  text-decoration: none;
}
a:hover {
  text-decoration: underline;
}