:root {
    --black: #000000;
    --almost-black: #080708;
    --blue: #3772FF;
    --blue-light: #3787ff;
    --red: #DF2935;
    --yellow: #FDCA40;
    --light: #E6E8E6;
    --white: #FFFFFF;
  }
  
  * {
    position: relative;
    box-sizing: border-box;
  }
  
  body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    font-size: 22px;
    line-height: 1.5;
    color: var(--white);
    background: var(--black);
    background-image: linear-gradient(to bottom right, var(--almost-black), var(--black));
  }
  
  .app {
    height: 100vh;
    display: flex;
  }
  
  .form-section {
    padding: 15px 0 0 15px;
    width: 25%;
    color: var(--light);
    flex-shrink: 0;
  }
  
  .images-section {
    padding: 15px 0 0 15px;
    width: 75%;
    height: 100vh;
    align-content: flex-start;
    flex-wrap: wrap;
    display: flex;
    overflow-y: auto;
  }
  
  .images-section a {
    margin: 0 15px 15px 0;
    padding-bottom: 20%;
    content: '';
    width: calc(33.33% - 15px);
    height: 0;
    display: block;
  }
  
  .images-section img {
    position: absolute;
    top: 0;
    width: 100%;
    height: 100%;
    border-radius: 4px;
    object-fit: contain;
    display: block;
  }
  
  @media screen and (max-width: 1200px) {
  
    .app {
      flex-direction: column;
    }
    
    .form-section {
      padding-right: 15px;
      padding-bottom: 15px;
      width: 100%;
    }
    
    .images-section {
      padding-top: 0;
      width: 100%;
      height: auto;
    }
  }
  
  @media screen and (max-width: 800px) {
    
    .images-section a {
      padding-bottom: 60%;
      width: calc(100% - 15px);
    }
  }
  
  /* Forms */
  form {
    width: 100%;
    flex-direction: column;
    display: flex;
  }
  
  input[type='file'] {
    margin: 0 0 12px;
    padding: 10px 10px;
    border-radius: 4px;
    font-size: 22px;
    color: var(--almost-black);
    background: var(--white);
  }
  
  input[type='submit'],
  button[type='button'] {
    padding: 13px 20px;
    font-size: 22px;
    font-weight: bold;
    color: var(--white);
    border: none;
    border-radius: 4px;
    outline: none;
    box-shadow: none;
    cursor: pointer;
    background: var(--blue);
    background-image: linear-gradient(to bottom, var(--blue-light), var(--blue));
    transition: box-shadow .2s ease;
  }
  
  input[type='submit']:hover,
  button[type='button']:hover {
    box-shadow: inset 0 -25px 25px var(--blue-light);
  }