con-1.css

.container {
    height: 100vh;
    width: 100%;
    /* background: url("./image/harry-shelton-pPxhM0CRzl4-unsplash-1.jpg")
      no-repeat center rgba(0, 0, 0, 1); */
    animation: change 15s linear alternate infinite;
    /* animation: forwards; */
  }
  @keyframes change {
    0% {
      color: black;
      background: url("./image/harry-shelton-pPxhM0CRzl4-unsplash-1.jpg")
        no-repeat center rgba(0, 0, 0, 1);
    }
    100% {
      color: white;
      background: url("./image/sean-pollock-PhYq704ffdA-unsplash.png")
        no-repeat center rgba(0, 0, 0, 1);
    }
  }

  .con-1 {
    height: 100vh;
    width: 100%;
    /* color: black; */
    /* color: white; */
  }
  .con-1 .logo{
    /* margin: 2rem auto; */
    height: 100%;
    /* border: solid 2px red; */
  }
  .con-1 .logo img{
    height: 120%;
  }
  .nav {
    display: flex;
    flex-wrap: nowrap;
    text-wrap:balance;
    height: 20%;
    width: 100%;
    /* border: solid 2px white; */
    padding: 0 1em;
    justify-content: space-around;
    align-items: center;
  }
  .nav ul {
    display: flex;
    flex-wrap: nowrap;
    /* border: solid 2px white; */
    font-size: larger;
    font-family: Arial, sans-serif;
    list-style-type: none;
    justify-content: space-between;
    align-items: center;
  }
  .nav ul li {
    cursor: pointer;
    pointer-events: all;
    margin: 1em;
    transition: all 0.2s;
  }
  .nav ul li a {
    text-decoration: none;
    color: black;
  }
  .nav ul li:hover {
    color: black;
    text-underline-offset: 5px;
    text-decoration: underline;
  }

  .main-content {
    height: 80%;
    width: 100%;
    display: grid;
    place-content: center;
    text-align: center;
    font-size: 2.5rem;
    /* border: solid 2px white; */
  }
  .main-content .btn {
    color: white;
    width: max-content;
    margin: auto;
    cursor: pointer;
    pointer-events: all;
    font-size: medium;
    padding: 1em 2em;
    margin: 1em auto;
    border-radius: 2em;
    text-decoration: none;
    background-color: #52adef;
  }
  .main-content .btn:hover {
    background-color: #52adef;
    filter: contrast(80%);
  }