制作篮球游戏.我做错了什么?

Question

所以我正在制作一款篮球游戏，一切都很奇怪，我只是需要帮助知道我做错了什么!我很困惑!这里是我的代码钢笔链接去检查代码https://codepen.io/cohanroderick123/pen/xxEBVRr可能要复制粘贴它。请帮助

$red: #D83204;
body{
text-align: center;
padding: 0;
margin:0;
background: lightBlue;
background: url(https://s3-us-west-2.amazonaws.com/s.cdpn.io/3194017/bballBg.png);
font-family:'Roboto', sans-serif;
position:relative;
background-size:cover;
background-repeat:no-repeat;
}
#Calque_1{
max-width: 100vw;
max-height: 100vh;
overflow:visible;
}
.ground{
background: #233033;
position: absolute;
z-index: 0;
height: 18.5vh;
width: 100vw;
bottom: 0;
left: 0;
}
button{
color: $red;
background: white;
border: none;
border-radius: 15px;
padding: 8px 10px;
margin-top:3vh;
font-size: 20px;
font-weight: 500;
border:solid grey 2px;
transition: all ease 0.3s;
cursor: pointer;
outline:none;
&:hover{
background: $red;
color: white;
}
}

Answer 1

它工作得很好，你只是缺少添加链接到正文
<script src="http://cdnjs.cloudflare.com/ajax/libs/gsap/1.18.0/TweenMax.min.js"></script>