.container{
/*width: 1654px;*/
width: 100%;
background-color: #f0f0f0;
margin: 0 auto;
}
.sidebar{
position: sticky;
bottom: 10px;
width: 400px;
margin: 5px;
background-color: teal;
height: 1000px;
display: inline-block;
}
.mainpage{
width: 1130px;
margin: 5px;
margin-left: 0px;
background-color: steelblue;
height: 6000px;
display: inline-block;
}
.footer{
height: 500px;
width: 1654;
margin: 0 auto;
margin-top: 10px;
background-color: purple
}
.test1{
background-color: red;
position: relative;
left: 0;
right: 0;
top: 0;
height: 200px;
}
.test2{
background-color: red;
position: relative;
left: 0;
right: 0;
bottom: 0;
height: 200px;
}
<body>
<div class="container">
<div class="sidebar">
<div class="test1">test1</div>
<div class="test2">test2</div>
</div>
<div class="mainpage">mainpage</div>
</div>
<div class="footer">footer</div>
</body>