How to remove the bottom border of a box with CSS

Question

I have a rectangular div, like the one above. I want to remove the bottom border (from C to D) in my div. How can I do this?.

Edit: Here is my CSS:

#index-03 {    position: absolute;    border: .1px solid #900;    border-width: .1px;    border-style: solid;    border-color: #900;    left: 0px;    top: 102px;    width: 900px;    height: 27px;  }

<div id="index-03"        style="background-color:limegreen; width:300px; height:75px;">  </div>

Answer 1

Just add in: border-bottom: none;

#index-03 {     position:absolute;     border: .1px solid #900;     border-bottom: none;     left:0px;     top:102px;     width:900px;     height:27px; } 

Answer 2

You can either set

border-bottom: none; 

or

border-bottom: 0; 

One sets the border-style to none.
One sets the border-width to 0px.

div {    border: 3px solid #900;      background-color: limegreen;     width:  28vw;    height: 10vw;    margin:  1vw;    text-align: center;    float: left;  }    .stylenone {    border-bottom: none;  }  .widthzero {    border-bottom: 0;  }

<div>  (full border)  </div>  <div class="stylenone">  (style)<br><br>    border-bottom: none;  </div>  <div class="widthzero">  (width)<br><br>  border-bottom: 0;  </div>

Side Note:
If you ever have to track down why a border is not showing when you expect it to, It is also good to know that either of these could be the culprit. Also verify the border-color is not the same as the background-color.