The width of the left border of an element in pixels. It includes the width of the vertical scrollbar if the text direction of the element is right-to-left and if there is an overflow causing a left vertical scrollbar to be rendered. clientLeft does not include the left margin or the left padding. clientLeft is read-only.
Note: When an element has display: inline, clientLeft returns 0 regardless of the element's border.
In the following example, the client area has a white background and a 24px black border-left. The clientLeft value is the distance from where the margin (yellow) area ends and the padding and content areas (white) begin: that is, 24px.
<div id="container">
<div id="contained">
<p>
Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod
tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim
veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea
commodo consequat.
</p>
</div>
</div>
#container {
margin: 3rem;
background-color: rgb(255, 255, 204);
border: 4px dashed black;
}
#contained {
margin: 1rem;
border-left: 24px black solid;
padding: 0px 28px;
overflow: auto;
background-color: white;
}