123movies-seo/resources/scss/_lazyload.scss

// img {
//   &.lazy {
//     opacity: 0;
//     transition: opacity ease-in-out 0.6s;
//     &.loaded {
//         opacity: 1;
//         transition: opacity ease-in-out 0.6s;
//     }
//   }
// }

img.lazy {
    opacity: 0;
}
img:not(.initial) {
transition: opacity 0.6s;
}
img.initial,
img.loaded,
img.error {
opacity: 1;
}