* {
  padding: 0;
  margin: 0;
  box-sizing: border-box;
}


body {
  height: 100vh;
  display: flex;
  background-image: url(img/pssdback.jpeg);
}


.memory-game {
  width: 789px;
  height: 789px;
  margin: auto;
  align-items: center;
  display: flex;
  flex-wrap: wrap;
  perspective: 1000px;
}

.memory-card {
  width: 24%;
  height: 24%;
  margin: 2px;
  position: relative;
  transform: scale(1);
  transform-style: preserve-3d;
  transition: transform .5s;
}

.memory-card:active {
  transform: scale(0.97);
  transition: transform .2s;
}

.memory-card.flip {
  transform: rotateY(180deg);
}

.front-face,
.back-face {
  width: 100%;
  height: 100%;
  padding: 5px;
  position: absolute;
  border-radius: 50px;
  backface-visibility: hidden;
  background:#000;
}

.front-face {
  transform: rotateY(180deg);
}
.social-icons {
  display: flex;
  justify-content: center;
  list-style: none;
  margin-top: 1rem;
  margin-bottom: 1rem;
  padding-left: 0;
}
.social-icons>li {
  margin-left: 0.25rem;
  margin-right: 0.25rem;
}
.social-icons a {
  position: relative;
  background-color: #eee;
  display: block;
  -webkit-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  user-select: none;
  transition: background-color .3s ease-in-out;
  width: 2.5rem;
  height: 2.5rem;
  border-radius: .25rem;
}
.social-icons a:hover {
  background-color: #2c2c2c;
}
.social-icons a::before {
  content: "";
  position: absolute;
  width: 1.2rem;
  height: 1.2rem;
  left: .65rem;
  top: .65rem;
  background: transparent no-repeat center center;
  background-size: 100% 100%;
}
.social-icons .social-icon-twitter::before {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 512 512'%3E%3Cpath fill='%231da1f2' d='M459.37 151.716c.325 4.548.325 9.097.325 13.645 0 138.72-105.583 298.558-298.558 298.558-59.452 0-114.68-17.219-161.137-47.106 8.447.974 16.568 1.299 25.34 1.299 49.055 0 94.213-16.568 130.274-44.832-46.132-.975-84.792-31.188-98.112-72.772 6.498.974 12.995 1.624 19.818 1.624 9.421 0 18.843-1.3 27.614-3.573-48.081-9.747-84.143-51.98-84.143-102.985v-1.299c13.969 7.797 30.214 12.67 47.431 13.319-28.264-18.843-46.781-51.005-46.781-87.391 0-19.492 5.197-37.36 14.294-52.954 51.655 63.675 129.3 105.258 216.365 109.807-1.624-7.797-2.599-15.918-2.599-24.04 0-57.828 46.782-104.934 104.934-104.934 30.213 0 57.502 12.67 76.67 33.137 23.715-4.548 46.456-13.32 66.599-25.34-7.798 24.366-24.366 44.833-46.132 57.827 21.117-2.273 41.584-8.122 60.426-16.243-14.292 20.791-32.161 39.308-52.628 54.253z'/%3E%3C/svg%3E");
  z-index: 100;
}