Make header sticky

Hello everyone

again, i would like to seeking help on this valuable forum

i have tried to make sticky header by applying this css code

#masthead {
	position: fixed;
	top: 0;
	width: 100%;
}

but the problem everyting in the content pulled to the top, i have try to set padding of the site-content, breadcrumbs, .header-widget-region just to make it alligned. but all i do is not worked for me

so how to make sticky header and make everything below the header allign ?

The page I need help with: [log in to see the link]