Create Fluid Background Image with CSS - html

Question

I am trying to build a simple fluid image that can resize based on screen size.
But I am having trouble to get the image smaller when the width of the browser gets smaller.
HTML:
<main>
<section class="slider-ctn">
<figure class="logo"></figure>
</section>
</main>
CSS:
.slider-ctn figure.logo {
margin: auto;
background-image: url('../Images/logo.200x100.png');
width: 200px;
height: 100px;
}

Answer 1

If you set the background-size to 100% 100% or cover the image will stretch to fit the container. Remove the width (or restrict the width by setting the parent's width) and set height: 0; padding-top: 50% on the figure to make the height of the figure half of the width, so the aspect ratio will match the image and be fluid.
* {margin:0;padding:0;}
.slider-ctn {
margin: auto;
width: 200px;
}
.slider-ctn figure.logo {
background: url('https://dummyimage.com/200x100/000/fff') top left no-repeat;
height: 0;
background-size: cover;
padding-top: 50%;
}
<main>
<section class="slider-ctn">
<figure class="logo"></figure>
</section>
</main>

Answer 2

Just add the following to your head tag with this code :
<meta name="viewport" content="width=device-width, initial-scale=1">

Answer 3

Another option using vw units and contain.
If you know the aspect ratio of your image you can use vw (view width) as your units for width and height.
I am using an image that has a 4x3 aspect ratio. If I want the width to always be 80% of the screen I will use 80vw. Then, my height will be 3/4 of my width, or 60vw.
Then be sure to use contain for your background sizing.
Try this css and see if it satisfies your needs:
.slider-ctn figure.logo {
margin: auto;
background-image: url('https://i.ytimg.com/vi/tntOCGkgt98/maxresdefault.jpg');
background-size: contain;
background-repeat: no-repeat;
width: 80vw;
height: 60vw;
border: 5px solid red;
}

Answer 4

You should add contain as background-size to your CSS:
.slider-ctn figure.logo {
margin: auto;
background-image: url('../Images/logo.200x100.png');
background-position:center center;
background-repeat:no-repeat;
background-size:contain;
width: 200px;
max-width:100%;
height: 100px;
display:inline-block;
}
Don't forgot to add position and repeat to background properties everytime when you use background images.
Also I added max-width to fit within the parent container if it is smaller than the logo container.
Example here
NOTE: Don't use cover in background-size because that will cut your
logo to fit only within width limits, contain will fit width and
height.

Answer 5

I think setting up the max-width of the image to 100% should do the trick.
.slider-ctn figure.logo {
background-image: url('../Images/logo.200x100.png');
background-repeat:no-repeat;
background-size:contain;
background-position:center;
width: 200px;
height: 100px;
}