Image On Theme Body Pixelated On Mobile

[blah12325]

Hello all! This is my first post on the forum, and I have scoured to ends trying to figure a solution but will explain what the problem is first; 

I am using a third party theme on a shopify website, and all is perfect except one small issue, when on mobile one of the banner images becomes super pixelated. 

-the theme is called rubix
-preview link here

It seems the solution would be to add in a portion that just disables the part of the theme that this scrolling background image is on (as you scroll the banner image stays static), but implementing something like this in theme.scss.liquid seems to not be working. 

@media only screen and (max-width: 749px){
#shopify-section-1576065013508 .container div:nth-child(1) {
    display: none;
}
}

I am very new to doing anything related to coding, but I presume one of the issues is that I need to figure out which shopify section I am calling on, and that is based on a pre-existing directory which was created within the theme itself by the theme developer? 

Any help would be greatly appreciated!

[Zworthkey]

Hii, @blah12325 
Can you give me a screenshot of your problem so,
I can solve it.
Thank You.

[blah12325]

Here you go!

[Zworthkey]

Hii, @blah12325 
Paste this code on top of the theme.scss file.

.velaBannerText.style1.mbGutter.bg_parallax.bg_image {
    background-image: none !important;

}

Thank You.

[blah12325]

That's amazing @Zworthkey thank you! is it possible to make the "background none" function just on the mobile version? the background image displays properly on full screens

[marcoswatanabe]

Here is your code working on mobile only:

@media only screen and (max-width: 749px){
  .velaBannerText.style1.mbGutter.bg_parallax.bg_image {
      background-image: none !important;
  }
}

[blah12325]

Thank you so very much! You rock guys!