css:
.flightNumber{
display: none;
-moz-transition: opacity 2000ms ease-in-out;
-o-transition: opacity 2000ms ease-in-out;
-webkit-transition: opacity 2000ms ease-in-out;
/*transition: opacity 2000ms ease-in-out;
opacity: 0;
}
.runIn{
-moz-transition: opacity 2000ms ease-in-out;
-o-transition: opacity 2000ms ease-in-out;
-webkit-transition: opacity 2000ms ease-in-out;
/*transition: opacity 2000ms ease-in-out;*/
opacity: 1;
display: block;
}html code:<p class='flightNumber'></p>
js code:$(".flightNumber").addClass("runIn")
![[Web front-end] Node.js quick start](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
display:none If this is added, the animation cannot be effective, because display:none means that this element is not parsed on the page, and all styles of this element are invalid. Under this premise, transition: opacity 2000ms ease-in-out; is Invalid, so no animation effect is possible.
Thanks for the invitation.
The number
display都去掉，另外前缀没必要写，直接原生就行。真有需要的话，可以先
.show()下嘛（反正你opacityis 0 and nothing can be seen).