index.css

body {
    margin: 0px;
}

.container {
    display: flex;
}

.sidebar {
    text-align: center;
    margin: 0px;
    padding: 0px;
    width: 200px;
    background-color:#555555;
    height: 100vh;
    overflow: auto;
}

.sidebar button {
    all: unset;
    width: 100%;
    font-size: 18px;
    display: block;
    color: #ffffff;
    text-decoration: none;
    max-height: 20px;
    padding: 20px 0;
    text-align: center;
    cursor: pointer;
}

.sidebar .active {
    font-weight: bold; 
    font-size: 20px;
    background-color: #8b139b;
}

.sidebar button:hover {
    background: #757575;
    color: #ffffff;
}

div.content{
    padding: 0;
    height: 800px;
}

.content *{
    margin-top:0;
}

.head p {
    font-size: 20px;
    margin: 20px;
    color: #ffffff;
    font-family: 'Trebuchet MS', 'Lucida Sans Unicode', 'Lucida Grande', 'Lucida Sans', Arial, sans-serif;;
}

img {
    margin-top: 20px;
}

a {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

iframe {
    display: block;
    width: 100%;
    height: 100vh;
}

#inst-wrapper {
    flex: 1;
    display: block;
    height: 100vh;
    
    position: relative;
}