Same background color, different gradient width - css

Question

I'm trying to get a background color on part of some tds, so that it looks similar to a progress bar background:
From left to somewhere in the middle, it's colored, and after that percentage, it's white.
And if it's 100%, of course, the whole td is colored.
The color, a linear-gradient, is the same on all tds, but the length will differ. I only have 3 lengths:
30%
70%
100%
Also 0%, but it's just empty then, so this is out of the question
For this, I'm using a specific class for each variation, .progress_**.
Every class has two linear-gradients on the background property.
This is my current working CSS:
.progress_30 {
background:
linear-gradient(to right,
rgba(0, 0, 0, 0) 0%,
rgba(255, 255, 255, 0) 30%,
rgba(255, 255, 255, 1) 30%
),
linear-gradient(to right, yellow, green)
;
}
.progress_70 {
background:
linear-gradient(to right,
rgba(0, 0, 0, 0) 0%,
rgba(255, 255, 255, 0) 70%,
rgba(255, 255, 255, 1) 70%
),
linear-gradient(to right, yellow, green)
;
}
.progress_100 {
background:
linear-gradient(to right,
rgba(0, 0, 0, 0) 0%,
rgba(255, 255, 255, 0) 100%,
rgba(255, 255, 255, 1) 100%
),
linear-gradient(to right, yellow, green)
;
}
As you can see, there is a lot that repeats.
I want at least to put the color in a separate .progress class, so it can be changed easily without altering the lengths, and so I can add or alter some lengths without touching the colors in the future.
So I tried this:
.progress {
background: linear-gradient(to right, yellow, green);
}
.progress_30 {
background:
linear-gradient(to right,
rgba(0, 0, 0, 0) 0%,
rgba(255, 255, 255, 0) 30%,
rgba(255, 255, 255, 1) 30%
)
;
}
.progress_70 {
background:
linear-gradient(to right,
rgba(0, 0, 0, 0) 0%,
rgba(255, 255, 255, 0) 70%,
rgba(255, 255, 255, 1) 70%
)
;
}
.progress_100 {
background:
linear-gradient(to right,
rgba(0, 0, 0, 0) 0%,
rgba(255, 255, 255, 0) 100%,
rgba(255, 255, 255, 1) 100%
)
;
}
This doesn't fully work: the white part on the right is the correct length. But on the left, I don't see my linear-gradient, only the page's background color (which isn't white).
Is there a way I can get as few repetitions as possible in CSS, at least have the linear-gradient's color set only once, or do I have to do it like in my first example?

Answer 1

You can rely on background-size and keep the gradient declaration within the same class:
div {
min-height: 50px;
}
.progress {
background:
linear-gradient(#fff, #fff) right no-repeat,
linear-gradient(to right, yellow, green);
}
.progress_30 {
background-size: 70% 100%, auto;
}
.progress_70 {
background-size: 30% 100%, auto;
}
.progress_100 {
background-size: 0% 100%, auto;
}
<div class="progress progress_30"></div>
<div class="progress progress_70"></div>
<div class="progress progress_100"></div>
You can simplify more using CSS variable in case you want to consider more percentage values:
div {
min-height: 50px;
}
.progress {
background:
linear-gradient(#fff, #fff) right/calc(100% - var(--p,50%)) 100% no-repeat,
linear-gradient(to right, yellow, green);
}
<div class="progress" style="--p:30%"></div>
<div class="progress" style="--p:68%"></div>
<div class="progress" style="--p:80%"></div>
<div class="progress" ></div>