光るボタン4色のデザインCSSコード（赤色・黄色・青色・緑色）

shiny-button.css

/************************************
** 光る赤いボタン
************************************/
.red-shiny a {
display: block;
position: relative;
z-index: 2;
overflow: hidden;
width: 100%;
font-weight: bold ;
border-bottom: solid 5px #bd6060 ;
border-radius: 5px;
background-color: #f88080 ;
color: #ffffff !important;
padding: 12px 0;
text-align: center;
text-decoration: none;
transition: .25s linear;
-webkit-transition: .25s linear;
-moz-transition: .25s linear;
}
.red-shiny {
display: block;
width: 100%;
margin-bottom: 1em;
}
.red-shiny a:hover {
-ms-transform: translateY(4px);
-webkit-transform: translateY(4px);
transform: translateY(4px);/*下に動く*/
border-bottom: none;/*線を消す*/
}
.red-shiny:active {
  border-bottom: none;
  box-shadow: 0 0 1px rgba(0, 0, 0, 0.2); /*影を小さく*/
  -webkit-transform: translateY(4px);
  -ms-transform: translateY(4px);
  transform: translateY(4px); /*下に動く*/
}
.red-shiny a:before {
display: block;
position: absolute;
z-index: -1;
left: -30%;
top: -50%;
content: "";
width: 100px;
height: 100px;
transform: rotate(20deg);
-webkit-transform: rotate(20deg);
-moz-transform: rotate(20deg);
background-image: linear-gradient(left, rgba(255,255,255,0) 0%, rgba(255,255,255,1) 50%,rgba(255,255,255,0) 100%);
background-image: -webkit-gradient(linear, left bottom, right bottom, color-stop(0%,rgba(255,255,255,0)), color-stop(67%,rgba(255,255,255,1)),color-stop(100%,rgba(255,255,255,0)));
background-image: -moz-linear-gradient(left, rgba(255,255,255,0) 0%, #ffffff rgba(255,255,255,1),rgba(255,255,255,0) 100%);
animation: shiny 3s infinite linear;
-webkit-animation: shiny 3s infinite linear;
-moz-animation: shiny 3s infinite linear;
}
@keyframes shiny {
    0% { transform: scale(0) rotate(45deg); 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 shiny {
    0% { -webkit-transform: scale(0) rotate(45deg); 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 shiny {
    0% { -moz-transform: scale(0) rotate(45deg); 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 shiny {
    0% { -ms-transform: scale(0) rotate(45deg); 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 shiny {
    0% { -o-transform: scale(0) rotate(45deg); 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; }
}
/************************************
** 光る黄色いボタン
************************************/
.yellow-shiny a {
display: block;
position: relative;
z-index: 2;
overflow: hidden;
width: 100%;
font-weight: bold ;
border-bottom: solid 5px #bf9d1e ;
border-radius: 5px;
background-color: #fad02d ;
color: #ffffff !important;
padding: 12px 0;
text-align: center;
text-decoration: none;
transition: .25s linear;
-webkit-transition: .25s linear;
-moz-transition: .25s linear;
}
.yellow-shiny {
display: block;
width: 100%;
margin-bottom: 1em;
}
.yellow-shiny a:hover {
-ms-transform: translateY(4px);
-webkit-transform: translateY(4px);
transform: translateY(4px);/*下に動く*/
border-bottom: none;/*線を消す*/
}
.yellow-shiny:active {
  border-bottom: none;
  box-shadow: 0 0 1px rgba(0, 0, 0, 0.2); /*影を小さく*/
  -webkit-transform: translateY(4px);
  -ms-transform: translateY(4px);
  transform: translateY(4px); /*下に動く*/
}
.yellow-shiny a:before {
display: block;
position: absolute;
z-index: -1;
left: -30%;
top: -50%;
content: "";
width: 100px;
height: 100px;
transform: rotate(20deg);
-webkit-transform: rotate(20deg);
-moz-transform: rotate(20deg);
background-image: linear-gradient(left, rgba(255,255,255,0) 0%, rgba(255,255,255,1) 50%,rgba(255,255,255,0) 100%);
background-image: -webkit-gradient(linear, left bottom, right bottom, color-stop(0%,rgba(255,255,255,0)), color-stop(67%,rgba(255,255,255,1)),color-stop(100%,rgba(255,255,255,0)));
background-image: -moz-linear-gradient(left, rgba(255,255,255,0) 0%, #ffffff rgba(255,255,255,1),rgba(255,255,255,0) 100%);
animation: shiny 3s infinite linear;
-webkit-animation: shiny 3s infinite linear;
-moz-animation: shiny 3s infinite linear;
}
@keyframes shiny {
    0% { transform: scale(0) rotate(45deg); 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 shiny {
    0% { -webkit-transform: scale(0) rotate(45deg); 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 shiny {
    0% { -moz-transform: scale(0) rotate(45deg); 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 shiny {
    0% { -ms-transform: scale(0) rotate(45deg); 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 shiny {
    0% { -o-transform: scale(0) rotate(45deg); 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; }
}
/************************************
** 光る青いボタン
************************************/
.blue-shiny a {
display: block;
position: relative;
z-index: 2;
overflow: hidden;
width: 100%;
font-weight: bold ;
border-bottom: solid 5px #3a76ba ;
border-radius: 5px;
background-color: #4f9df4 ;
color: #ffffff !important;
padding: 12px 0;
text-align: center;
text-decoration: none;
transition: .25s linear;
-webkit-transition: .25s linear;
-moz-transition: .25s linear;
}
.blue-shiny {
display: block;
width: 100%;
margin-bottom: 1em;
}
.blue-shiny a:hover {
-ms-transform: translateY(4px);
-webkit-transform: translateY(4px);
transform: translateY(4px);/*下に動く*/
border-bottom: none;/*線を消す*/
}
.blue-shiny:active {
  border-bottom: none;
  box-shadow: 0 0 1px rgba(0, 0, 0, 0.2); /*影を小さく*/
  -webkit-transform: translateY(4px);
  -ms-transform: translateY(4px);
  transform: translateY(4px); /*下に動く*/
}
.blue-shiny a:before {
display: block;
position: absolute;
z-index: -1;
left: -30%;
top: -50%;
content: "";
width: 100px;
height: 100px;
transform: rotate(20deg);
-webkit-transform: rotate(20deg);
-moz-transform: rotate(20deg);
background-image: linear-gradient(left, rgba(255,255,255,0) 0%, rgba(255,255,255,1) 50%,rgba(255,255,255,0) 100%);
background-image: -webkit-gradient(linear, left bottom, right bottom, color-stop(0%,rgba(255,255,255,0)), color-stop(67%,rgba(255,255,255,1)),color-stop(100%,rgba(255,255,255,0)));
background-image: -moz-linear-gradient(left, rgba(255,255,255,0) 0%, #ffffff rgba(255,255,255,1),rgba(255,255,255,0) 100%);
animation: shiny 3s infinite linear;
-webkit-animation: shiny 3s infinite linear;
-moz-animation: shiny 3s infinite linear;
}
@keyframes shiny {
    0% { transform: scale(0) rotate(45deg); 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 shiny {
    0% { -webkit-transform: scale(0) rotate(45deg); 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 shiny {
    0% { -moz-transform: scale(0) rotate(45deg); 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 shiny {
    0% { -ms-transform: scale(0) rotate(45deg); 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 shiny {
    0% { -o-transform: scale(0) rotate(45deg); 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; }
}
/************************************
** 光る緑色のボタン
************************************/
.green-shiny a {
display: block;
position: relative;
z-index: 2;
overflow: hidden;
width: 100%;
font-weight: bold ;
border-bottom: solid 5px #6ca25f ;
border-radius: 5px;
background-color: #90d581 ;
color: #ffffff !important;
padding: 12px 0;
text-align: center;
text-decoration: none;
transition: .25s linear;
-webkit-transition: .25s linear;
-moz-transition: .25s linear;
}
.green-shiny {
display: block;
width: 100%;
margin-bottom: 1em;
}
.green-shiny a:hover {
-ms-transform: translateY(4px);
-webkit-transform: translateY(4px);
transform: translateY(4px);/*下に動く*/
border-bottom: none;/*線を消す*/
}
.green-shiny:active {
  border-bottom: none;
  box-shadow: 0 0 1px rgba(0, 0, 0, 0.2); /*影を小さく*/
  -webkit-transform: translateY(4px);
  -ms-transform: translateY(4px);
  transform: translateY(4px); /*下に動く*/
}
.green-shiny a:before {
display: block;
position: absolute;
z-index: -1;
left: -30%;
top: -50%;
content: "";
width: 100px;
height: 100px;
transform: rotate(20deg);
-webkit-transform: rotate(20deg);
-moz-transform: rotate(20deg);
background-image: linear-gradient(left, rgba(255,255,255,0) 0%, rgba(255,255,255,1) 50%,rgba(255,255,255,0) 100%);
background-image: -webkit-gradient(linear, left bottom, right bottom, color-stop(0%,rgba(255,255,255,0)), color-stop(67%,rgba(255,255,255,1)),color-stop(100%,rgba(255,255,255,0)));
background-image: -moz-linear-gradient(left, rgba(255,255,255,0) 0%, #ffffff rgba(255,255,255,1),rgba(255,255,255,0) 100%);
animation: shiny 3s infinite linear;
-webkit-animation: shiny 3s infinite linear;
-moz-animation: shiny 3s infinite linear;
}
@keyframes shiny {
    0% { transform: scale(0) rotate(45deg); 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 shiny {
    0% { -webkit-transform: scale(0) rotate(45deg); 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 shiny {
    0% { -moz-transform: scale(0) rotate(45deg); 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 shiny {
    0% { -ms-transform: scale(0) rotate(45deg); 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 shiny {
    0% { -o-transform: scale(0) rotate(45deg); 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; }
}

⬇️このコードの使い方を紹介しているブログ記事はこちら
https://noripon.blog/2020/03/09/how-to-make-wordpress-shortcode-css-shiny-button/