<style>
body {
margin: 0;
font-family: Arial, Helvetica, sans-serif;
}
.topnav {
overflow: hidden;
display: flex;
justify-content: center;
align-items: center;
}
.topnav a {
color: #3a414e;
text-align: center;
padding: 14px 16px;
text-decoration: none;
font-size: 17px;
border-radius: 20px 20px 20px 20px;
}
.topnav a:hover {
background-color: #c7d9c7;
color: black;
}
.topnav a.active {
background-color: #0f9f10;
color: white;
}
.center {
display: block;
margin-left: auto;
margin-right: auto;
}
</style>