Image banner problems

I am facing two problems with my image banner.

1. Firstly, I am showing two different banners (one for mobile and one for desktop). However, the banner on mobile is not fully showing. This is the CSS code i am using:

.banner__media:first-child {
    width: 100%;
}
.banner__media+.banner__media {
    display: none;
}
@media screen and (max-width: 749px) {
	.banner__media:first-child {
		display: none;
	}
	.banner__media+.banner__media {
		width: 100%;
		display: block !important;
	}
}

2. Moreover, I want to remove the empty space on top of my image banner. I tried remove the padding from both the header and the image banner, but it is not working.

Actual image:

How it looks on mobile:

Empty Space:

Theme: Dawn

URL: shbqa.com

Password: 1

Edit: I was able to remove the empty space under the header by adding the following code to base.css:

#shopify-section-sections--21915631353890__header{
  margin-top: -10px !important;
}

Hello @SHBQA

Go to online store ---------> themes --------------> actions ------> edit code-------> assets----->section-image-banner.CSS ----> line number 65
and add this code

@media screen and (max-width: 749px) {
.banner--large.banner--mobile-bottom:not(.banner--adapt) .banner__media,
{
height: 73rem;
width: 100%;
}
}

and the result will be

If this was helpful, hit the like button and mark the job as completed.
Thanks

Thank you so much for you fast reply, however, its not working for me.

Edit: on inspect element (phone view) it is showing as it shows in your image, but not on my actual phone.

Add This css in your edit code > style.css file

.shopify-section-header-sticky sticky-header.header-wrapper.color-scheme-1.gradient.header-wrapper--border-bottom {
    bottom: 0 !important;
}

This worked out perfectly, thank you so much. Can you help me show the full length of the image on mobile?

This is the actuall size of your image, but if you want to increase the height, you can add and increase it in this code.

.banner__media.media.banner__media-half.scroll-trigger.animate--fade-in {
    height: 39rem !important;
}

You choose your custom height