Glow Pulse CTA
X-ray · layers
Parameters
How this effect works
The glow is one box-shadow whose size and opacity ride a sine wave — the button literally breathes: the shadow inflates to the full spread at the top of each breath and relaxes near zero at the bottom. Slow periods (3–5s) read as calm confidence; fast ones read as urgency. That single number is most of the design.
The halo ring makes the breath visible at a distance: a thin circle sitting exactly on the button's outline scales up and fades out once per breath, synchronized to the same clock, like a ripple leaving the surface. And the hover boost is the interaction payoff — the moment your cursor arrives, the same clock simply runs faster, so the button visibly gets excited about being touched. No second animation, no state machine: one clock, one multiplier.