Remove grey line under collection debut theme

[LabelSource]

in grey line under my last collection. been unable to remove and no other collection has this, please help.

debut theme

[oscprofessional]

@LabelSource ,

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[LabelSource]

hi

https://jtsxwern346x1qhm-25590600.shopifypreview.com

bottom collection, this is a draft theme

[oscprofessional]

@LabelSource ,

.slideshow__controls.slider-buttons.no-js-hidden {
    border: 0;
}

Add this css at the bottom of Online Store->Theme->Edit code->Assets->base.scss.liquid

[LabelSource]

Thank you!!!