body { background-color: #042421; color: #e7fffd; transition: 0.3s; }
body.light-mode { background-color: #f4f4f4; color: #333; }

.sidebar { width: 250px; height: 100vh; background: #001f1f; position: fixed; padding: 20px; }
.dropdown { display: none; }
.dropdown.show { display: flex; flex-direction: column; }