YouTube with hidden sidebar by KABA

/* ==UserStyle==
@name         YouTube with hidden sidebar
@version      20250131.08.51
@namespace    https://userstyles.world/user/KABA
@description  As the title says.
@author       KABA
@license      No License
==/UserStyle== */

@-moz-document regexp("https://www.youtube.com/watch?.*") {
/* Domain */

/* - Base */
:root {
	--show-duration: .64s;
	--show-delay: .2s;
	--hide-duration: .4s;
	--hide-delay: 0;

	--transition:
		var(--show-duration)
		var(--show-delay)
		ease-in-out;
}

/* - Sidebar */
#secondary {
	/* Hide elements */
	transition: var(--transition);

	&:not(:hover, :focus-within) {
		transition-duration: var(--hide-duration);
		transition-delay:    var(--hide-delay);
		opacity: 0;
	}

	/* Disable click on Hidden */
	> * {
		transition:
			calc(
				var(--show-duration) +
				var(--show-delay)
			)
			allow-discrete
		;
	}
	&:not(:hover, :focus-within) {
		> * {
			pointer-events: none;
			transition-duration: inherit;
		}
	}
}
}