Animations
blink
You can make the whole button blink:

type: 'custom:button-card'
color_type: card
entity: binary_sensor.intruder
name: Intruder Alert
state:
- value: 'on'
color: red
icon: mdi:alert
styles:
card:
- animation: blink 2s ease infinite
- operator: default
color: green
icon: mdi:shield-check