Starfield

Small bright specks flicker in and out around text or a section.

Add a "Sparkles" effect (also called glitter or twinkle particles) to [where].
Small star-shaped specks should pop in, twinkle and fade out around the text at scattered spots and random moments: light and quick.
Keep the sparkles decorative and hidden from screen readers, never cover the text itself, and stop them for users who prefer reduced motion.

Many small dots drift, connect or react to the pointer across the background.

Add a "Particles" background (also called floating particles or a particle field) to [where].
Small dots of different sizes should float and drift slowly in gentle, wandering paths, each at its own pace: calm and airy.
Keep the number of dots modest so it stays light on slower devices, pause it when it is off screen, and stop it for users who prefer reduced motion.

Diagonal streaks with glowing tails fall across a card or section.

Add a "Meteors" effect (also called a meteor shower or shooting stars) to [where].
A handful of small streaks with fading tails should shoot diagonally across the area at random moments, each one quick and then gone.
Keep them few so it stays an accent, clip them to the area's edges, and stop them for users who prefer reduced motion.

A fine speckled texture overlays the page, sometimes flickering like film grain.

Add a "Noise / Grain Texture" overlay (also called film grain or a noise background) to [where].
A fine, faint speckled texture should sit over the surface and flicker in small jumps like film grain: subtle, never strong enough to muddy the content.
Let clicks pass through the overlay, generate the texture once instead of every frame, and keep it still for users who prefer reduced motion.

Particles spiral around a center like a whirlpool.

Add a "Vortex" background (also called swirling particles) to [where].
Small particles should spiral inward around a center point like a whirlpool, fading in at the edge and fading out as they reach the middle, in a smooth, continuous swirl.
Keep the particle count modest, pause it when off screen, and stop the swirl for users who prefer reduced motion.

Layered wavy lines or shapes undulate horizontally.

Add a "Wave Background" (also called a wavy background or animated waves) to [where].
A few layered wave shapes should roll sideways at slightly different speeds so they overlap and shift like water: slow and smooth.
Make each wave loop seamlessly without a visible jump, and stop the waves for users who prefer reduced motion.

A glowing pulse travels along a line connecting two elements.

Add an "Animated Beam" effect (also called a connecting beam) to [where].
A short glowing pulse should travel along the line that connects two elements, moving steadily from one end to the other and then starting again: smooth and calm.
Keep the connecting line itself visible at all times, and hold the pulse still for users who prefer reduced motion.