body {
  font-family: Arial, sans-serif;
  margin: 0;
  background: #f4f6f9;
}

.header {
  background: #1f2937;
  color: white;
  padding: 15px;
  text-align: center;
}

.nav {
  display: flex;
  justify-content: center;
  gap: 15px;
  padding: 15px;
  background: white;
  box-shadow: 0 2px 5px rgba(0,0,0,0.05);
}

.nav button {
  padding: 8px 15px;
  border: none;
  background: #2563eb;
  color: white;
  border-radius: 6px;
  cursor: pointer;
}

.nav button:hover {
  background: #1d4ed8;
}

.container {
  padding: 20px;
}

.card {
  background: white;
  padding: 15px;
  margin-bottom: 20px;
  border-radius: 10px;
  box-shadow: 0 2px 6px rgba(0,0,0,0.05);
}

table {
  width: 100%;
  border-collapse: collapse;
}

th, td {
  padding: 10px;
  border-bottom: 1px solid #eee;
  text-align: left;
}

th {
  background: #f9fafb;
}

.summary-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 15px;
}

.summary-card {
  background: white;
  padding: 20px;
  border-radius: 10px;
  text-align: center;
  box-shadow: 0 2px 6px rgba(0,0,0,0.05);
}