body {
    margin: 0;
    font-family: Arial, sans-serif;
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 20px;
    background-color: #333;
    color: white;
}

.header-right {
    display: flex;
    align-items: center;
    gap: 10px;
}

#side-menu {
    position: fixed;
    top: 0;
    left: -100%;
    width: 250px;
    height: 100%;
    background-color: #333;
    color: white;
    transition: left 0.3s ease-in-out;
}

#side-menu.visible {
    left: 0;
}

/* Theme Styles */
body.retro {
    background-color: #111111;
    color: #00ff00;
}

body.dark {
    background-color: #000000;
    color: #ffff00;
}

body.light {
    background-color: #ffffff;
    color: #000000;
}