.corona-btn {
    display: block;
    position: relative;
    width: 90%;/*ボタンの幅*/
    padding: 10px 0;
    margin: 10px auto;
    background-color: #ed4545;/*ボタンの色*/
    box-shadow: 0 3px 0 0 rgba(198, 39, 39, 1);/*影の色(rgbaの値を変更)*/
    border-radius: 5px;
    font-weight: bold;
    font-size: 20px;
    color: #fff;
    text-align: center;
    text-decoration: none;
    overflow: hidden;
}
.corona-btn a{
    text-decoration: none;
}
.corona-btn:hover {
    text-decoration: none;
    color: #fff;
    box-shadow: none;
    -webkit-transform: translateY(3px);
}
.corona-btn:before {
    position: absolute;
    content: '';
    display: inline-block;
    top: -180px;
    left: 0;
    width: 30px;
    height: 100%;
    background-color: #fff;
    transition: 0.2s
    transform: rotate(45deg);
    animation: corona-btn 3s ease-in-out 0s infinite;
    -webkit-transform: rotate(45deg);
    -webkit-animation: corona-btn 3s ease-in-out 0s infinite;
    -moz-transform: rotate(45deg);
    -moz-animation: corona-btn 3s ease-in-out 0s infinite;
    -ms-transform: rotate(45deg);
    -ms-animation: corona-btn 3s ease-in-out 0s infinite;
    -o-transform: rotate(45deg);
    -o-animation: corona-btn 3s ease-in-out 0s infinite;
}
@keyframes corona-btn {
    0% { transform: scale(0) rotate(0deg); opacity: 0; }
    80% { transform: scale(0) rotate(45deg); opacity: 0.5; }
    81% { transform: scale(4) rotate(45deg); opacity: 1; }
    100% { transform: scale(50) rotate(45deg); opacity: 0; }
}
@-webkit-keyframes corona-btn {
    0% { -webkit-transform: scale(0) rotate(0deg); opacity: 0; }
    80% { -webkit-transform: scale(0) rotate(45deg); opacity: 0.5; }
    81% { -webkit-transform: scale(4) rotate(45deg); opacity: 1; }
    100% { -webkit-transform: scale(50) rotate(45deg); opacity: 0; }
}
@-moz-keyframes corona-btn {
    0% { -moz-transform: scale(0) rotate(0deg); opacity: 0; }
    80% { -moz-transform: scale(0) rotate(45deg); opacity: 0.5; }
    81% { -moz-transform: scale(4) rotate(45deg); opacity: 1; }
    100% { -moz-transform: scale(50) rotate(45deg); opacity: 0; }
}
@-ms-keyframes corona-btn {
    0% { -ms-transform: scale(0) rotate(0deg); opacity: 0; }
    80% { -ms-transform: scale(0) rotate(45deg); opacity: 0.5; }
    81% { -ms-transform: scale(4) rotate(45deg); opacity: 1; }
    100% { -ms-transform: scale(50) rotate(45deg); opacity: 0; }
}
@-o-keyframes corona-btn {
    0% { -o-transform: scale(0) rotate(0deg); opacity: 0; }
    80% { -o-transform: scale(0) rotate(45deg); opacity: 0.5; }
    81% { -o-transform: scale(4) rotate(45deg); opacity: 1; }
    100% { -o-transform: scale(50) rotate(45deg); opacity: 0; }
}