Moving my header banner color towards the left

Topic summary

A Shopify store owner wants to modify their header banner color to appear only in the top-left corner instead of spanning the entire width of the site. They specifically want the colored area to cover just the logo region.

Proposed Solution:

  • Remove or override existing background colors throughout the header
  • Use CSS pseudo-elements (:before) to create a colored square
  • Apply CSS transforms to rotate the square and position it in the top-left
  • Adjust text colors that depend on contrasting backgrounds

Current Issue:
The initial CSS implementation created a red rotated square, but it’s overlapping the logo incorrectly. The user has shared screenshots showing the problem and is requesting further assistance to properly position the colored banner element.

Status: Ongoing troubleshooting of CSS positioning and styling.

Summarized with AI on November 18. AI used: claude-sonnet-4-5-20250929.

Hi guys! I need help with my website, so for all the website themes the banner is going across the entire website but is there a way I can move the banner to just the top left?

Here is my website:

https://31s9t78lrjydybk3-79949955347.shopifypreview.com

Heres How I want The Banner to Look Like:

I want the banner color to just go over the logo and thats it.

Any help would be greatly appreciated thanks!!

Roughly you’d remove/override the existing background colors; you’d also need to adjust any colors that were dependent on a contrasting background.

Then add custom css adding a psuedo element with the background color making a square of color then rotate it to get the slope then move it left/right up/down to get the alignment right.

https://help.shopify.com/en/manual/online-store/themes/theme-structure/extend/add-css

Example css:

.header-wrapper.color-accent-1.gradient {
    background-color: initial;
}

.header-wrapper:before {
 content:" ";

 position: absolute;
 z-index: 0;
 top: -150px;
 left: -150px;
 transform: rotate(45deg);

 display: block;
 width: 300px;
 height: 300px;

 background-repeat: no-repeat;
 background-color: red;
}

.header__heading-link {
 left: -110px;
 position: relative;
}

If you need this customization fleshed out contact me for services.
Please always provide context, examples: store url, theme name, post url(s) , or any further detail.
Contact Info in signature.

Thank you so much for the quick reply!! It added the sideways square but its red and overlapping the logo, can you please help me with this?