Composition of CSS Animations [BlinkOn 21]

Picked one by one from a mixed channel. Transcript check: both title readers certain; 5 of 5 sampled certain picks confirmed by transcript, none failed. Channel rule: Include only single-topic technical talks whose title names a concrete system, protocol or technique being explained (deep dives, 'Life of X', Chrome University, '101'/overview, architecture talks, the 'What's Up With That' explainer series); exclude keynotes, discussions, status updates, vision/goals talks, lightning-talk/demo reels and meetup sessions.