style.css

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

html{
    font-size: 62.5%;
    box-sizing: border-box;
}

body{
  font-family: sans-serif;
  color: white;
  line-height:1.5;
  height: 100vh;
  position: relative;
  display: flex;
  align-items: center;  
  justify-content: center;
  background: linear-gradient(145deg, #252525, #2c2c2c);
}

.open-modal{
  outline: none;
  font-size: 2rem;
  font-weight: 600;
  padding: 1.25rem 2.4rem;
  margin: 2rem 3rem;
  border: none;
  border-radius: 3rem;
  background: linear-gradient(145deg, #252525, #2c2c2c);
  color: white;
  box-shadow:  4px 4px 19px #202020,
                -4px -4px 19px #323232;
  cursor: pointer;
}

.close-modal{
  position: absolute;
  top: 1.2rem;
  right: 2rem;
  font-size: 5rem;
  color: rgb(255, 255, 255);
  cursor: pointer;
  border: none;
  background: none;
}
  
  h1 {
    font-size: 2.5rem;
    margin-bottom: 2rem;
  }
  
  p {
    font-size: 1.8rem;
  }

   .hidden {
    display: none;
  } 
  
  .modal {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 70%;
    color: #ffffff;
    padding: 6rem;
    border-radius: 5px;
    background: linear-gradient(145deg, #252525, #2c2c2c);
    z-index: 10;
    backdrop-filter: blur(3px);

  }
  
  .overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(24, 23, 23, 0.6);
    backdrop-filter: blur(3px);
    z-index: 5;
  }