1let links = ["https://docs.google.com/presentation/d/1EvMNGgEtPjw5j-bodHtqwzdVH8OCgHXdNNVZkpd3Tn8/edit#slide=id.g12fb24ad41f_0_82","https://drive.google.com/file/d/1PhPFlO0lwqGj9hLg3Ph2TeGnvonbum3l/view","https://ontake.dev/school/downloads/rust-particle-simulator.zip"]
 2
 3function toggleCardExpand(cardIndex){
 4    if (document.getElementsByClassName("card")[cardIndex].className == "card"){
 5        document.getElementsByClassName("card")[cardIndex].className="card card-expanded";
 6        const node = document.createElement("a");
 7        node.className="card-link";
 8        node.href=links[cardIndex];
 9        node.innerHTML="Link";
10        document.getElementsByClassName("card")[cardIndex].appendChild(node);
11
12    } else{
13        document.getElementsByClassName("card")[cardIndex].className="card";
14        document.getElementsByClassName("card")[cardIndex].lastElementChild.className+=" card-link-destroy";
15        setTimeout(function(){document.getElementsByClassName("card")[cardIndex].removeChild(document.getElementsByClassName("card")[cardIndex].lastElementChild);},500);
16        
17    }
18}