To get you started, we added some CSS rules to style.css.

<html>
<head>
<style>

div {
border-radius: 7px;
font-family: "Verdana", Sans-serif;
margin-bottom: 5px;
text-align: center;
}

.theme {
background-color: ghostWhite;
height: 300px;
}

.options {
height: 70px;
background-color: gainsboro;
}

button {
border: none;
border-radius: 5px;
}
</style>
</head>
<body>
<div class="theme" id="theme" style="background-color: ghostwhite">
<p id="current" class="current">Light Mode</p>
<img id="themeImg" src="https://mimo.app/i/light-icon.png">
</div>
<div class="options">
<button id="dark" class="darkBtn" onclick="updateColor(this.id)">dark</button>
<button id="light" class="lightBtn" onclick="updateColor(this.id)">light</button>
<button id="ninja" class="ninjaBtn" onclick="updateColor(this.id)">ninja</button>
</div>
</body>
</html>]]>