body { font-family: Arial, sans-serif; margin: 0; padding: 0; background-color: #f4f4f4; }
header { background: #007bff; color: white; padding: 1rem; display: flex; justify-content: space-between; align-items: center; }
nav button { background: white; color: #007bff; border: none; padding: 0.5rem 1rem; cursor: pointer; border-radius: 4px; margin-left: 0.5rem; }
main { padding: 2rem; max-width: 800px; margin: 0 auto; background: white; border-radius: 8px; box-shadow: 0 0 10px rgba(0,0,0,0.1); margin-top: 2rem;}
.hidden { display: none; }
.card { border: 1px solid #ddd; padding: 20px; border-radius: 10px; margin-bottom: 20px; }
form { display: flex; flex-direction: column; gap: 10px; }
input, select, button { padding: 10px; border-radius: 4px; border: 1px solid #ccc; }
button[type="submit"] { background: #28a745; color: white; border: none; cursor: pointer; }