Right, lets see where this get us, add to Custom CSS:
.header-layout-branding-center-nav-center .header-title-nav-wrapper {
flex: 0 0 100%;
}
.header-layout-branding-center-nav-center .header-title-nav-wrapper .header-nav {
background: #5f7315;
padding: 12px 0px;
}
.header .header-announcement-bar-wrapper {
padding-bottom: 0vw;
padding-left: 0vw;
padding-right: 0vw;
}
Let me know when you've got that code in and we'll see if any tweaks are needed.