WhiteSur-gtk-theme/src/other/firefox/common/pages/newtab.css

/* about:newtab */

@-moz-document url("about:newtab"), url("about:home") {
body {
	--newtab-background-color: var(--gnome-browser-before-load-background) !important;
	--newtab-background-color-secondary: var(--gnome-menu-background) !important;
	--newtab-primary-action-background: var(--theme-primary-color) !important;
	--newtab-primary-element-text-color: #ffffff !important;
	--newtab-overlay-color: var(--gnome-tabstoolbar-background) !important;
	--newtab-border-color: var(--gnome-toolbar-border-color) !important;
	--fxview-background-color: var(--gnome-browser-before-load-background) !important;
	--fxview-background-color-secondary: var(--gnome-menu-background) !important;
}

.modalOverlayOuter {
	background: color-mix(in srgb, var(--gnome-browser-before-load-background) 80%, transparent) !important;
}

.context-menu {
	background: var(--gnome-menu-background) !important;
	border-radius: 12px !important;
	box-shadow: var(--gnome-popover-shadow), 0 0 0 1px var(--gnome-popover-border-color) !important;
	padding: 6px !important;
}

@media (prefers-color-scheme: dark) {
	.context-menu {
		border: 1px solid rgba(255, 255, 255, 0.06) !important;
	}
}

.context-menu > ul {
	padding: 0 !important;
}

.context-menu > ul > li > a,
.context-menu > ul > li > button {
	border-radius: 6px !important;
	padding: 6px 12px !important;
}

.context-menu > ul > li.separator {
	border-bottom: 1px solid var(--gnome-popover-separator-color) !important;
}

.home-section .section .switch {
	width: 30px !important;
	height: 20px !important;
}

.home-section .section .slider::before {
	height: 12px !important;
	width: 12px !important;
	inset-inline-start: 3px;
	bottom: 3px;
}
}