body {
  margin: 0;
  font-family: 'Inter', sans-serif;
  background-color: #f6f8fa;
  color: #333;
}
.container {
  max-width: 800px;
  margin: 4rem auto;
  background: #fff;
  border-radius: 12px;
  box-shadow: 0 4px 10px rgba(0,0,0,0.05);
  padding: 2rem;
}
nav {
  background: #e2e8f0;
  padding: 1rem;
  display: flex;
  justify-content: center;
  gap: 1rem;
}
nav a {
  text-decoration: none;
  padding: 0.5rem 1rem;
  background: #2563eb;
  color: white;
  border-radius: 8px;
  transition: background 0.2s;
}
nav a:hover {
  background: #1e40af;
}
button, input[type=submit] {
  background: #2563eb;
  color: white;
  border: none;
  padding: 0.5rem 1rem;
  border-radius: 8px;
  cursor: pointer;
}
button:hover, input[type=submit]:hover {
  background: #1e40af;
}
input, select {
  padding: 0.5rem;
  border-radius: 8px;
  border: 1px solid #ccc;
  margin-bottom: 1rem;
  width: 100%;
  box-sizing: border-box;
}
table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 1rem;
}
th, td {
  padding: 0.75rem;
  border: 1px solid #e5e7eb;
  text-align: left;
}