.texte { font-size: 25px; 
 text-align: center;
padding :  5px;
margin-bottom :10px;
}

.cadre { font-size: 20px;
  font-weight:bold;
padding :  5px;
text-align: center;
border: 2px solid black;
border-radius :  10px;
margin-bottom :10px;
background-color: #bb00ff;
}

.image_centree{
  width : 20%;
  height : 40%;
  border: 1px #23282d solid; 
  text-align: center;
   margin-left: auto;
   margin-right: auto;
   } 
body {
    margin: auto;
    font-family: -apple-system, BlinkMacSystemFont, sans-serif;
    overflow: auto;
    background: linear-gradient(315deg, rgba(101,0,94,1) 3%, rgba(60,132,206,1) 38%, rgba(48,238,226,1) 68%, rgba(255,25,25,1) 98%);
    animation: gradient 15s ease infinite;
    background-size: 400% 400%;
    background-attachment: fixed;
}

@keyframes gradient {
    0% {
        background-position: 0% 0%;
    }
    50% {
        background-position: 100% 100%;
    }
    100% {
        background-position: 0% 0%;
    }
}

.wave {
    background: rgb(255 255 255 / 25%);
    border-radius: 1000% 1000% 0 0;
    position: fixed;
    width: 200%;
    height: 12em;
    animation: wave 10s -3s linear infinite;
    transform: translate3d(0, 0, 0);
    opacity: 0.8;
    bottom: 0;
    left: 0;
    z-index: -1;
}

.wave:nth-of-type(2) {
    bottom: -1.25em;
    animation: wave 18s linear reverse infinite;
    opacity: 0.8;
}

.wave:nth-of-type(3) {
    bottom: -2.5em;
    animation: wave 20s -1s reverse infinite;
    opacity: 0.9;
}

@keyframes wave {
    2% {
        transform: translateX(1);
    }

    25% {
        transform: translateX(-25%);
    }

    50% {
        transform: translateX(-50%);
    }

    75% {
        transform: translateX(-25%);
    }

    100% {
        transform: translateX(1);
    }
}
a:hover {{
color: red;
}

a:visited {
color: purple;
}

a:focus {
color: yellow;
  background: gray;
}