Why a div child forces the parent to grow and ignore flex 1?

unicodes · 2025-08-21T16:36:01.01+00:00

I have a parent div called main, which contains two children: c1 and c2.-c1 has a fixed width of 200px.-c2 is set to flex: 1 and also has width: 100%.Inside c2, there is another child element. When this child becomes visible, it forces c2 to grow, ignoring the flex: 1 behavior.If I add overflow: hidden to c2, everything works as expected. Without it, c2 doesn’t respect the flex: 1.Do you know why this happens?

unicodes

3 months ago

I have a parent div called main, which contains two children: c1 and c2.

-c1 has a fixed width of 200px.
-c2 is set to flex: 1 and also has width: 100%.

Inside c2, there is another child element. When this child becomes visible, it forces c2 to grow, ignoring the flex: 1 behavior.

If I add overflow: hidden to c2, everything works as expected. Without it, c2 doesn’t respect the flex: 1.

Do you know why this happens?
Lucas G

3 months ago

flex 1 would mean it should grow
unicodes

3 months ago

changing flex-grow to 0 or 1 or flex-shrink, there is no difference. I can not understand why forces the parent to grow outside the flex rule. It grow's like flex was unset.
Andreas Møller

3 months ago

Unless you set a fixed width an element will grow to fit it’s content
unicodes

3 months ago

I believe the package horizontal scroll has something that does this. I do not have this error in other places.
Andreas Møller

3 months ago

That is possible

Why a div child forces the parent to grow and ignore flex 1?

unicodes

Lucas G

unicodes

Andreas Møller

unicodes

Andreas Møller