Firstly, the settings you are applying are for the parent element of the image, not the image itself. Therefore, it won't directly affect the image.
When it comes to styling the image directly, avoid using those mentioned settings. Instead, use width: 100%
to make the image fill the container width, along with a max-width
set to the original pixel width of the image. This prevents distortion if the image is smaller than the container.
To achieve this, your CSS rule should be:
.formular-banner > img {
width: 100%;
max-width: 1240px; /* insert actual image width here */
height: auto;
}
If the image is smaller than the container and you wish to center it horizontally within the container (which defaults to 100% width as a block element), you can utilize this additional rule for the container:
.formular-banner {
text-align: center;
}