div {
    /* レイアウトのルール */
    display: flex;
    /* 上がわの余白 */
 }
 
 img {
   max-width: 100%;
   height: auto;
}

 
   /* リンク */
   a {
       /* 文字の色 */
       color: yellow;
       /* 文字の装飾 */
       text-decoration: none;
       /* 並べ方 */
       display: block;
       /* 文字の整列 */
       text-align: center;
       /* 文字の大きさ */
       font-size: 275%;
       /* 左がわの余白 */
       margin-left: 5%;
       /* 右がわの余白 */
       margin-right: 5%;
     }
 

   b {
     /* 文字の色 */
     color: yellow;
     /* 文字の装飾 */
     text-decoration: none;
     /* 並べ方 */
     display: block;
     /* 文字の整列 */
     text-align: center;
     /* 文字の大きさ */
     font-size: 65%;
     /* 左がわの余白 */
     margin-left: 5%;
     /* 右がわの余白 */
     margin-right: 5%;
     /* 下がわの余白 */
     margin-bottom: 5%;
     }

   
   c {
       /* 文字の色 */
       color: yellow;
       /* 文字の装飾 */
       text-decoration: none;
       /* 並べ方 */
       display: block;
       /* 文字の整列 */
       text-align: center;
       /* 文字の大きさ */
       font-size: 125%;
       /* 左がわの余白 */
       margin-left: 15%;
       /* 右がわの余白 */
       margin-right: 15%;
       /* 上がわの余白 */
       margin-top: 5%;
    }

    d {
        /* 文字の色 */
        color: yellow;
        /* 文字の装飾 */
        text-decoration: none;
        /* 並べ方 */
        display: block;
        /* 文字の整列 */
        text-align: center;
        /* 左がわの余白 */
        margin-left: 5%;
        /* 右がわの余白 */
        margin-right: 5%;
        bottom: 0; /*下寄せの指定*/
      }

iframe { width: 100%; height: 500px; overflow: auto; }
   
 body {
     background: -moz-linear-gradient(45deg, #02e1ba 0%, #26c9f2 29%, #d911f2 66%, #ffa079 100%);
     background: -webkit-linear-gradient(45deg, #02e1ba 0%,#26c9f2 29%,#d911f2 66%,#ffa079 100%);
     background: linear-gradient(45deg, #02e1ba 0%,#26c9f2 29%,#d911f2 66%,#ffa079 100%);
     background-size: 400% 400%;
     -webkit-animation: Gradient 15s ease infinite;
     -moz-animation: Gradient 15s ease infinite;
     animation: Gradient 15s ease infinite;
     /*min-height: calc(100vh - 2rem);*/
     display: flex;
     flex-direction: column;
     align-items: stretch;
     justify-content: space-evenly;
     overflow: hidden;
     position: relative; 
 }
 
 body::before, 
 body::after {
     content: "";
     width: 70vmax;
     height: 70vmax;
     position: absolute;
     background: rgba(255, 255, 255, 0.07);
     left: -20vmin;
     top: -20vmin;
     animation: morph 15s linear infinite alternate, spin 20s linear infinite;
     z-index: 1;
     will-change: border-radius, transform;
     transform-origin: 55% 55%;
     pointer-events: none; 
 }
     
 body::after {
     width: 70vmin;
     height: 70vmin;
     left: auto;
     right: -10vmin;
     top: auto;
     bottom: 0;
     animation: morph 10s linear infinite alternate, spin 26s linear infinite reverse;
     transform-origin: 20% 20%; 
 }
 
 @-webkit-keyframes Gradient {
     0% {
         background-position: 0 50%
     }
     50% {
         background-position: 100% 50%
     }
     100% {
         background-position: 0 50%
     }
 }
 
 @-moz-keyframes Gradient {
     0% {
         background-position: 0 50%
     }
     50% {
         background-position: 100% 50%
     }
     100% {
         background-position: 0 50%
     }
 }
 
 @keyframes Gradient {
     0% {
         background-position: 0 50%
     }
     50% {
         background-position: 100% 50%
     }
     100% {
         background-position: 0 50%
     }
 }
 
 @keyframes morph {
   0% {
     border-radius: 40% 60% 60% 40% / 70% 30% 70% 30%; }
   100% {
     border-radius: 40% 60%; } 
 }
 
 @keyframes spin {
   to {
     transform: rotate(1turn); 
   } 
 }
     .st0{display:none;}
     .st1{display:inline;}
     .st2{opacity:0.29;}
     .st3{fill:#FFFFFF;}
     .st4{clip-path:url;fill:#FFFFFF;}
     .st5{clip-path:url;}
     .st6{clip-path:url;}
     .st7{clip-path:url;}
     .st8{clip-path:url;}
     .st9{fill:none;}
     .st10{clip-path:url;}
     .st11{opacity:0.7;}
     .st12{clip-path:url;}
     .st13{opacity:0.2;}
     .st14{clip-path:url;}
     .st15{opacity:0.3;fill:#FFFFFF;enable-background:new    ;}