.start{
    overflow: hidden;
    background: lightgreen;
    position: relative;
    height: calc(100vh - 80px);
    display: flex;
align-items: center;
}
body{
    margin: 0;
}
.button{
    padding: 15px 25px;
    float: left;
    background: purple;
    color: white;
    width: 80px;
    text-align: center;
    border-radius: 5px;
}

.button.right{
    margin-left: 30px;
}
.container{
    width: 50%;
    margin-left: 10%;
    box-sizing: border-box;
    margin-bottom: 100px;
}
.startimage{
    position: absolute;
top: 0;
bottom: 0;
margin-top: auto;
width: 60%;
right: 0;
}

a{
    text-decoration: none;
}