extension.css

<style>html,
body {
    font-family: "Open Sans", sans-serif;
    font-size: 20px;
    margin: 0;
    min-height: 180px;
    
    width: 84px;
}


h2 {
    font-family: "Menlo", monospace;
    font-size: 21px;
    font-weight: 40;
    margin: 0;
    color: black;
}

a:link,
a:visited {
    color: aqua;
    outline: 0;
    text-decoration: none;
}

img {
  display: block;
  margin-left: 30%;
  width: 30px;

}

.extension-icon {
    align-items: center;
    border-bottom: 0.5px solid #dadada;
}

.content {
    margin-left: 10%;
    padding: 5px 1px;
    font-size: 13px;
}

.small-icons {
    border-top: 0.5px solid #dadada;
    height: 50px;
    width: 100%;
}

.logo {
    padding: 15px;
}

.logo-icon {
    vertical-align: text-bottom;
    margin-right: 15px;
    
}

.version {
    margin-left: 60%;
    font-size: 10px;
}

.flex-container {
    display: flex;
     justify-content: space-between;
    flex-wrap: wrap;
    padding: 10px 10px;
}
.flex-container > div {
  width: 100px;
  margin: 10px;
  text-align: center;
  line-height: 50px;
  font-size: 30px;
}

.flex {
    opacity: 1;
    transition: opacity 0.2s ease-in-out;
   width: 50px;
}

.flex:hover {
    opacity: 0.4;
}

.flex .fa {
    font-size: 40px;
    color: brown;
}

</style>