Mesh Gradient

Colors in a gradient background slowly shift, pan or rotate.

Add an "Animated Gradient" background (also called a gradient animation or moving gradient) to [where].
The colors of the gradient should slowly pan across the area in a soft, continuous drift, with no visible jump when the loop restarts.
Keep text on top readable against every color, and stop the movement for users who prefer reduced motion.

Soft blurred bands of color drift like an aurora behind content.

Add an "Aurora Background" (also called a northern lights gradient) to [where].
Soft, blurry bands of color should drift and sway slowly behind the content, overlapping and blending like northern lights: very slow and dreamy.
Keep the text on top readable, avoid re-blurring the bands on every frame so it stays smooth, and stop the drift 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.

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.