body {
    background-color: #000000;
    color: #ffffff;
    box-sizing: border-box;
    margin: 0;
}

a, a:visited {
    color: #ffffff;
}

.container {
    text-align: center;
    vertical-align: middle;
    /* Ссылки должны быть поверх куба, иначе по ним не кликнуть */
    position: relative;
    z-index: 1;
    /* border: 4px solid rgb(255, 5, 5); */
}
.tank {
    position: absolute;
    top: 480px;
    left: 50%;
    transform: translate(-50%, 0%);
    /* border: 2px solid rgb(0, 255, 13); */
    }

.end {
    position: absolute;
    top: 830px;
    left: 50%;
    transform: translate(-50%, 0%);
    /* border: 2px solid rgb(0, 255, 13); */
    }

.certificate {
    display: flex; 
    justify-content: center;
    align-items: center;
    /* border: 2px solid yellow; */
    }

.img {  
    width: 390px;
    }

.spinner {
    width: 250px;
    height: 250px;
    animation: spinner-y0fdc1 10s infinite ease;
    transform-style: preserve-3d;
   }
   
   .spinner > div {
    background-color: rgba(0,77,255);
    height: 100%;
    position: absolute;
    width: 100%;
    border: 2px solid #001f69;
   }
   
   .spinner div:nth-of-type(1) {
    transform: translateZ(-125px) rotateY(180deg);
   }
   
   .spinner div:nth-of-type(2) {
    transform: rotateY(-270deg) translateX(50%);
    transform-origin: top right;
   }
   
   .spinner div:nth-of-type(3) {
    transform: rotateY(270deg) translateX(-50%);
    transform-origin: center left;
   }
   
   .spinner div:nth-of-type(4) {
    transform: rotateX(90deg) translateY(-50%);
    transform-origin: top center;
   }
   
   .spinner div:nth-of-type(5) {
    transform: rotateX(-90deg) translateY(50%);
    transform-origin: bottom center;
   }
   
   .spinner div:nth-of-type(6) {
    transform: translateZ(125px);
   }
   
   @keyframes spinner-y0fdc1 {
    0% {
     transform: rotate(45deg) rotateX(-25deg) rotateY(25deg);
    }
   
    50% {
     transform: rotate(45deg) rotateX(-385deg) rotateY(25deg);
    }
   
    100% {
     transform: rotate(45deg) rotateX(-385deg) rotateY(385deg);
    }
   }

   @keyframes fade {
    0% { opacity: 0; }
    11.11% { opacity: 1; }
    33.33% { opacity: 1; }
    44.44% { opacity: 0; }
    100% { opacity: 0; }
  }
  
  .fadein { position:relative; width:70%;}
  .fadein img { position:absolute; width:100%; left:0; right:0; opacity:0; animation-name: fade; animation-duration: 12s; animation-iteration-count: infinite; }
  .fadein img:nth-child(1) { animation-delay: 0s; }
  .fadein img:nth-child(2) { animation-delay: 2s; }
  .fadein img:nth-child(3) { animation-delay: 4s; }
  .fadein img:nth-child(4) { animation-delay: 6s; }
  .fadein img:nth-child(5) { animation-delay: 8s; }
  .fadein img:nth-child(6) { animation-delay: 10s; }