.site-header nav a,
.site-header nav a.active {
    color: #fff;
    background: transparent;
    transition: background-color .16s ease;
}

.site-header nav a.nav-threat-feed:hover,
.site-header nav a.nav-threat-feed:focus-visible {
    color: #fff;
    background: var(--cyan);
}

.site-header nav a.nav-vulnerabilities:hover,
.site-header nav a.nav-vulnerabilities:focus-visible {
    color: #fff;
    background: var(--orange);
}

.site-header nav a.nav-mitre-heatmap:hover,
.site-header nav a.nav-mitre-heatmap:focus-visible {
    color: #fff;
    background: #f7512f;
}

.site-header nav a:focus-visible {
    outline: 1px solid #fff;
    outline-offset: 2px;
}