1. css 애니메이션 일시 정지하기
https://css-tricks.com/how-to-play-and-pause-css-animations-with-css-custom-properties/
참조
스와이퍼 api
https://swiperjs.com/swiper-api
https://swiperjs.com/swiper-api#events
https://www.tutorialdocs.com/tutorial/swiper/api-events.html
https://swiperjs.com/demos/450-watchslidesvisibility/core
https://www.kookmin.ac.kr/comm/board/user/46c025a625a3234f240ddb1d819a1816/index.do
https://www.thinbug.com/q/43774759
https://jsfiddle.net/eond/od9na61g/
https://jsfiddle.net/mLf75j4s/2/
https://github.com/nolimits4web/Swiper/issues/1615
https://codepen.io/udovichenko/pen/LGeQae
https://ionicframework.com/docs/api/slides