body {font-family: Arial, sans-serif; margin: 2rem; background: #f9f9f9; color: #333;}
nav button {margin-right: 0.5rem; padding: 0.5rem 1rem; cursor: pointer;}
nav button.active {background: #0066cc; color: #fff;}
#content {margin-top: 1rem;}
.term {border-bottom: 1px solid #ccc; padding: 0.3rem 0;}