body { font-family: Arial; margin: 20px; }
nav a { margin-right: 15px; text-decoration: none; font-weight: bold; }
nav a.active { color: blue; }
table { border-collapse: collapse; width: 100%; margin-top: 10px; }
th, td { border: 1px solid #ccc; padding: 8px; text-align: left; }
th { background-color: #f0f0f0; }
input[type="text"], input[type="number"], input[type="date"], select { width: 90%; }
button { padding: 5px 10px; margin: 2px; }
.alert { background-color: #ffe0e0; padding: 5px; margin: 5px 0; }