Header Blowing Out in Mobile View

Topic summary

A store owner reported that their header section was causing horizontal scrolling on mobile devices, despite using a separate mobile image. The issue stemmed from the header width exceeding the viewport on smaller screens.

Solutions Provided:
Multiple community members offered CSS fixes targeting the header’s minimum width on mobile:

  • Adding min-width: 100% to .section-header .header for screens under 749px
  • Setting min-width: 100% !important on the specific header element for screens under 750px
  • Using min-width: unset on .header-wrapper .header for screens under 989px

All solutions involved adding CSS code to the theme’s base.css file via Shopify Admin → Online Store → Theme → Edit code.

Resolution:
The issue was successfully resolved after the store owner implemented one of the suggested CSS fixes.

Summarized with AI on October 28. AI used: claude-sonnet-4-5-20250929.

Hello,

I manage thebukshop.com store. Recently the header section widened so there is a horizontal scroll. I am using a second image for the mobile view.

Please see attached screenshot and thanks in advance for your help.

Best,

Mike

1 Like

@BukShop please add this css to the very end of your base.css file and check,
Shopify Admin → Online Store ->Theme → Edit code → base.css

@media screen and (max-width:749px)
{.section-header .header{min-width: 100%;}}
1 Like

Hi @BukShop

You can try to follow this step
Step 1: Go to Edit code
Step 2: Find file base.css and add this code at the end of the file

@media screen and (max-width: 750px) {
header.header.header--top-left.header--mobile-center.page-width.header--has-menu.header--has-social.header--has-localizations {
    min-width: 100% !important;
}
}

Result

Best,

DaisyVo

1 Like

Hi @BukShop

I see the issue on your site, you can follow this way to fix it.
let try to add Custom CSS to your Theme Settings:

@media screen and (max-width: 989px) {
  .header-wrapper .header {
    min-width: unset;
  }
}

The result will be:

1 Like

That worked, thank you!