Responsive image based on container height - html

Question

I'm working on recreating my website and I would like to have images that appear on the size that categorize the sections. I would like these images to be responsive based on the height of the container. For example, if the container is 600px tall I want the image to be 600px tall regardless of the width. Right now I'm using background-size: contain; which works in desktop mode, but after a certain width, the image starts to get shorter in favor of staying the width of the container.
It works fine in desktop mode:
In mobile I get this:
When I want this:
I hope that makes sense. Also bear in mind that this isn't a finished concept so it looks pretty bad as it is even when I "hack" it to work in mobile

Answer 1

You can use media-queries:
#media only screen and (max-width: 600px) {
img {
background-size:cover;
}
}
You can read more about media- queries:https://www.w3schools.com/css/css_rwd_mediaqueries.asp
You can read more about background-size:https://www.w3schools.com/cssref/css3_pr_background-size.asp

Answer 2

One important thing when asking for help is doing your best to explain your problem as best as you can. Things like putting part of the code you have for example could really improve how fast you'd be answered and have your problem solved.
With that said, I'd recommend changing your css to something like the following:
.hero {
width: 100vw;
height: 100vh;
background-image: url(../images/hero.jpg);
background-size: cover;
background-position: center, center;
}
The background-size: cover along with background-position: center will make sure that it displays in the way you want in mobile. Not necessarily exactly that part of the image though, maybe you'll have to work on an image editor.
The width: 100vw and height: 100vh that I used in this example, are the size of the container in which the image is the background, that is also relevant when it comes to how the picture is displayed. vw is viewport width, vh is viewport height. This unit is good for working with responsive displays, as it takes in consideration the screen to determine the size of whatever styling you put it in.
Since this is already working in desktop in the way you want, I'd suggest using a media query so you'd only change the way it's displayed in mobile, for example.
It would be something like
#media only screen and (max-width: 480px) {
.hero {
width: 100vw;
height: 100vh;
background-image: url(../images/hero.jpg);
background-size: cover;
background-position: center, center;
}
}
As suggested in another answer, take a look into media queries to choose which one is appropriate for what you're trying to achieve. You can use many media queries, such as one for mobile, one for tablets and one for desktop.