画布不会滚动页面-Canvasdoesn'tscrollwithpage

const c = document.getElementById('canvas');
const ctx = c.getContext('2d');
ctx.moveTo(0, 0);
ctx.lineTo(200, 200);
ctx.stroke();

.app-container {
  display: flex;
  height: 100%;
  position: fixed;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
}

.app-nav-bar {
    flex: 0 0 230px;
    border: 1px solid #aaa;
    background: #eef1f7 no-repeat 0 100%;
    position: absolute;
    top: 0;
    bottom: 0;
    width: 200px;
}

.header-and-body {
    width: 100%;
    display: flex;
    flex-flow: column;
    margin-left: 200px;
}

.app-header {
  flex: 0 0 45px;
  border: 1px solid #aaa;
}

.main-view-container {
    display: flex;
    height: 100%;
    overflow-y: auto;
}

.tournament-container {
    margin-left: 20px;
}

canvas {
  position: absolute;
  z-index: -1;
}

.contents {
  height: 1000px;
  width: 1000px;
}

    
Navs
    

      
Header
      

        

          
          

            
Here are my contents
            
Some other stuff
            
This should scroll