* { 
    box-sizing: border-box; 
    transition: all 0.125s ease 0s;
  }
  
  body {
    margin: 0;
    padding: 0;
    background: #fff;
  }
  
  body:before, body:after {
    content: "IMAGES FROM UNSPLASH.COM";
    position: absolute;
    top: 0px;
    color: #00000000;
    left: 50%;
    transform: translateX(-50%);
    text-shadow: 0 -1px 1px #000000ab, 0 1px 1px #ffffff82;
    font-family: Arial, serif;
    padding: 2px 10px;
    border-radius: 2px;
    font-size: 9px;
    display: flex;
    align-items: flex-end;
    line-height: 14px;
  }
  
  body:after {
    top: inherit;
    bottom: 0;
    position: relative;
    margin-top: -12px;
    transform: translateX(-100%);
    margin-left: 90px;
    width: 150px;
  }
  
  img { 
    width: 100%;
  }
  
  .gallery {
    display: flex;
    padding: 5px;
    flex-wrap: wrap;
  }
  
  .column {
    flex: 25%;
    padding: 5px;
  
  }
  
  .column img {
    margin-top: 5px;
    cursor: pointer;
  }
  
  .column img:active {
    height: auto; 
    width: auto;
    max-width: 80%;
    position: fixed;
    left: 50%;
    top: 50%;
    border: 10px solid #fff;
    margin: 0px;
    box-shadow: 0 0 1000px 1000px #fff8;
    transform: translateX(-50%) translateY(-50%);
  }
  
  
  @media (max-width: 768px) {
    .column {
      flex: 50%;
    }
  }
  
  @media (max-width: 500px) {
    .column {
      flex: 100%;
    }
  }