<!-- style.css -->
body { margin: 0; font-family: 'Segoe UI', sans-serif; background: #ffde00; color: #000; transition: background 0.3s, color 0.3s; display: flex; flex-direction: column; }
header { background: #FFDE00; color: #000; text-align: center; padding: 15px 0; }
.topbar { display: flex; align-items: center; justify-content: center; position: relative; }
.logo-img { max-height: 50px; }
.yellow-btn { background: #FFDE00; color: #000; border: none; padding: 10px 15px; border-radius: 6px; cursor: pointer; }
.menu-toggle { position: absolute; left: 10px; }
.theme-toggle { position: absolute; right: 10px; }
nav { width: 200px; position: fixed; top: 0; left: 0; height: 100%; background: #111; padding-top: 80px; transform: translateX(-220px); transition: transform 0.3s; z-index: 1000; }
nav ul { list-style: none; padding: 0; margin: 0; }
nav ul li { position: relative; }
nav ul li a { color: #ffde00; text-decoration: none; display: block; padding: 12px 20px; }
nav ul li a:hover, .dropdown:hover > .dropbtn { background: #ffde00; color: #000; border-radius: 6px; }
.dropdown-content { display: none; flex-direction: column; background: #222; position: relative; }
.dropdown-content li a { padding: 10px 20px; }
.dropdown:hover .dropdown-content { display: flex; }
main { flex: 1; padding: 30px; margin-left: 0; margin-bottom: 60px; transition: margin-left 0.3s; }
.welcome, .content { background: white; padding: 30px; border-radius: 12px; box-shadow: 0 5px 15px rgba(0,0,0,0.2); }
.hidden { display: none; }
footer { position: fixed; bottom: 0; left: 0; width: 100%; background: #111; color: #ffde00; text-align: center; padding: 12px; z-index: 1000; }
body.dark-mode { background: #111; color: #ffde00; }
body.dark-mode header { background: #000; color: #ffde00; }
body.dark-mode nav { background: #000; }
body.dark-mode nav ul li a, body.dark-mode .dropdown-content li a { color: #ffde00; }
body.dark-mode .welcome, body.dark-mode .content { background: #222; color: #ffde00; }
@media (max-width: 1024px) { nav { transform: translateX(-220px); } }
nav.active { transform: translateX(0); }