body {
   background: url('img/bg.jpg') no-repeat center center fixed;
   overflow: auto;
   background-repeat: no-repeat;
   -moz-background-size: 100%;
   -webkit-background-size: 100%;
   -o-background-size: 100%; 
   background-size: cover; 
}

ul{
   background-color: rgba(0, 0, 0, 0.2);
   padding: 0 30px;
   margin: 0;
   backdrop-filter: blur(4px);
   position: relative;
   /* make UL exactly viewport height and distribute items evenly */
   height: 100vh;
   display: flex;
   flex-direction: column;
   gap: 0;
}
li, ul {
   list-style-type: none;
}
ul {
   max-width: 100vw;
}
.descr { 
   padding: 10px 0;
}

/* Give descr fixed space at top */
ul > li:first-child {
   flex: 0 0 auto;
}

/* All buttons below descr get equal space */
ul > li.button {
   flex: 1 1 0;
   display: flex;
   align-items: center;
   justify-content: center;
}

@media screen and (min-width: 1282px) {
   .contacts {
      position: relative;
      z-index: 3;
   }



   .logo {
      top: 40px;
      left: 40px;
      position: absolute;
      z-index: 99999;
   }
   
   
}

@media screen and (max-width: 1281px) {
   body{
      overflow: auto;
   }
   .contacts {
      position: relative;
      z-index: 3;
   }


   .logo {
      top: 15px;
      left: 15px;
      position: absolute;
      z-index: 99999;
   }
   ul {
      max-width: 100vw;
      height: 100vh;
      gap: 0;
      display: flex;
      flex-direction: column;
   }
   
   /* Mobile: Give descr fixed space at top */
   ul > li:first-child {
      flex: 0 0 auto;
   }
   
   /* Mobile: buttons stretch to fill remaining height equally */
   ul > li.button {
      flex: 1 1 0; /* возвращаем растягивание чтобы заполнить экран */
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0; /* убираем все отступы */
      padding: 0; /* убираем все внутренние отступы */
   }
   
}

@keyframes shadow {
   from {
     box-shadow: 0 0 55px 10px white;
   }
   to {
     box-shadow: 0 0 90px 20px white;
   }
 }
 .button {
   padding-bottom: 10px;
 }
 .button:hover {
 transition: 1s;
}
 .button:hover {
   transform: scale(1.2);
  }