.nav {
    position: fixed;
    top: 0;
    margin-top: 10px;
    font-family: 'Muli', sans-serif;  
    font: black;
    cursor: pointer;
    display: flex;
    width: 20%;
    background: rgb(249, 250, 251);
    padding: 15px;
    font-family: inherit;
    font-size: 16px;
    border: 0;
    border-radius: 5px;
  }

body {
    padding: 0;
    margin: 0;
    height: 90vh;
    display: flex;
    justify-content: center;
    align-items: center;
    background: black;
  }
  
  .card {
    width: 0;
    height: 0;
    border-top: 100px solid #eee;
    border-right: 170px solid #ddd;
    border-bottom: 100px solid #ccc;
    border-left: 170px solid #ccc;
  }
  
  .heart {
    width: 32px;
    height: 32px;
    background-color: #ff3838;
    transform: translate(-50%, -50%) rotate(45deg);
    animation: heartbeat 1.4s linear infinite;
  }
  
  .heart:before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: #ff3838;
    transform: translateY(-50%);
    border-radius: 50%;
  }
  
  .heart:after {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: #ff3838;
    transform: translateX(-50%);
    border-radius: 50%;
  }
  
  @keyframes heartbeat {
    0% { transform: translate(-50%, -50%) rotate(45deg) scale(1); }
    25% { transform: translate(-50%, -50%) rotate(45deg) scale(1); }
    30% { transform: translate(-50%, -50%) rotate(45deg) scale(1.4); }
    50% { transform: translate(-50%, -50%) rotate(45deg) scale(1.2); }
    70% { transform: translate(-50%, -50%) rotate(45deg) scale(1.4); }
    100% { transform: translate(-50%, -50%) rotate(45deg) scale(1); }
  }