Code for arrows in CSS
.arrow-left {
  display: inline-block;
  
  position: relative;
  width: 0; 
  height: 0; 
  border-top: 0.35em solid transparent;
  border-bottom: 0.35em solid transparent; 
  /* arrow border color */
  border-right: 0.35em solid blue; 
}
.arrow-left:after {
  content: "";
  position: absolute;
  top: -0.35em;
  left: 1px;
  width: 0; 
  height: 0; 
  border-top: 0.35em solid transparent;
  border-bottom: 0.35em solid transparent; 
  /* arrow color */
  border-right: 0.35em solid #fff; 
}