How to change the width of menu bar on dawn theme

[twacomm-store]

How do you change the width of the menu/navigation bar to full page on dawn theme? I dont want to change the width of the header but only the width of the menu bar to full page.

[techDynasty]

@twacomm-store Do you mind if you share the product URL. Also if it is password protected  then share the pass. If you have issue to share the pass , you can share the pass in my inbox.

[EliskaM]

Hello there, I have same requirement. I tried the code editing but it seems it's not working or maybe I'm doing something wrong.. Is it still possible to ask you for help and share my url and pass please? 
Many thanky in advance.

[techDynasty]

@twacomm-store 

>> From your Admin panel, click Online Store > Themes >Actions > Edit code
>> find and open the base.css file
>> Paste the code below at the very bottom of the file.

@media(min-width:1000px){
    .header--top-left{
        grid-template-columns: 1fr 1fr !important;
        width: 100% !important;
        padding: 0 !important;
        margin: 0 !important;
        max-width: unset !important;
    }
    .header__icons{
        width: max-content !important;
        justify-self: center !important;
        margin-left: 27rem !important;
    }
    .header__heading{
        width: 80% !important;
        justify-self: flex-end !important;
    }
}