You don't need JavaScript.
Pass a CSS var() from HTML to CSS and use calc() to get the percentages
.progress {
background: green;
height: 2em;
background: linear-gradient(to right, green calc(var(--val) * 10%), red calc(var(--val) * 10%));
background-size: 100%;
}
<div class="progress" style="--val:1"></div><br>
<div class="progress" style="--val:7"></div><br>
.progress {
background: red;
height: 2em;
}
.progress::before {
content: "";
display: block;
height: inherit;
background: green;
width: calc(var(--val) * 10%);
}
<div class="progress" style="--val:1"></div><br>
<div class="progress" style="--val:7"></div><br>
The most straightforward approach is to use an absolutely positioned child in a relatively positioned parent and set its width as the progress.
function setProgress(percent) {
const range = document.querySelector('.range');
const progress = range.querySelector('.progress');
progress.style.width = `${percent}%`
}
setProgress(70);
.range {
position: relative;
height: 20px;
background-color: #ed3a23;
border: 2px solid #000;
box-sizing: border-box;
overflow: hidden;
}
.progress {
position: absolute;
left: 0;
top: 0;
width: 0;
height: 100%;
background-color: #4db24c;
border-right: 3px solid #000;
}
<div class="range">
<div class="progress"></div>
</div>
Here's pure HTML & CSS
.bar-wrap {
display: flex
}
.col {
display: block;
text-align:center;
width: var(--size)
}
.bar {
height: 50px;
width: 100%;
border: 3px solid #000;
background: var(--background)
}
.cgreen {
color: green
}
.cred {
color: red
}
<div class="bar-wrap">
<div class="col cgreen" style="--size:70%;">
<h3 class="heading">Correct</h3>
<div class="bar" style="--background:green"></div>
<p class="label">70%</p>
</div>
<div class="col cred" style="--size:30%;">
<h3 class="heading">Wrong</h3>
<div class="bar" style="--background:red"></div>
<p class="label">30%</p>
</div>
</div>