body {
  background-color: purple;
}
.navbar {
    width: 15vw;
    height: 100vh;
    position: fixed;
    float: left;
    top: 0;
    bottom: 0;
    left: 0;
}
.main {
    width: 85vw;
    height: 100vh;
    position: fixed;
    float: right;
    top: 0;
    bottom: 0;
    right: 0;
}
#ad {
    right: 10px;
    text-align: right;
    top: 10px;
    position: absolute;
    left: 80vw;
}