/* Smart sticky header: visible at top, hides on scroll-down, reappears on scroll-up. */
header.dmg-header {
	position: sticky;
	top: 0;
	left: 0;
	right: 0;
	z-index: 1000;
	background: rgba(255, 255, 255, 0.92);
	backdrop-filter: saturate(180%) blur(8px);
	-webkit-backdrop-filter: saturate(180%) blur(8px);
	transform: translateY(0);
	transition: transform 0.28s ease, box-shadow 0.28s ease;
	will-change: transform;
}

header.dmg-header.dmg-header--hidden {
	transform: translateY(-100%);
}

/* Subtle shadow once you've scrolled away from the very top. */
header.dmg-header:not(.dmg-header--hidden) {
	box-shadow: 0 1px 0 rgba(0, 0, 0, 0.04), 0 6px 16px -8px rgba(0, 0, 0, 0.08);
}

/* Honor reduced motion: skip the slide animation. */
@media (prefers-reduced-motion: reduce) {
	header.dmg-header {
		transition: none;
	}
}