:root {
    --red: hsl(0, 78%, 62%);
    --cyan: hsl(180, 62%, 55%);
    --orange: hsl(34, 97%, 64%);
    --blue: hsl(212, 86%, 64%);
    --dark-grey: hsl(234, 12%, 34%);
    --grey: hsl(212, 6%, 44%);
    --white: hsl(0, 0%, 100%);
  }

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

  body {
    font-family: 'Poppins', sans-serif;
    font-size: 15px;
    background-color: var(--white);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 80px 20px;
  }

  .header {
    text-align: center;
    max-width: 540px;
    margin-bottom: 60px;
  }

  .thin-text {
    font-weight: 200;
    font-size: 28px;
    color: var(--dark-grey);
    margin-bottom: 0;
  }

  .bold-text {
    font-weight: 600;
    font-size: 28px;
    color: var(--dark-grey);
    margin-bottom: 20px;
  }

  .description {
    color: var(--grey);
    line-height: 1.7;
    padding: 0 10px;
  }

  .card-container {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 30px;
    max-width: 1140px;
  }

  .column {
    display: flex;
    flex-direction: column;
    gap: 30px;
  }

  .card {
    background-color: var(--white);
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
    max-width: 350px;
    position: relative;
    overflow: hidden;
  }

  .card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    height: 4px;
    width: 100%;
  }

  .supervisor::before {
    background-color: var(--cyan);
  }

  .team-builder::before {
    background-color: var(--red);
  }

  .karma::before {
    background-color: var(--orange);
  }

  .calculator::before {
    background-color: var(--blue);
  }

  .card h2 {
    color: var(--dark-grey);
    font-size: 20px;
    margin-bottom: 10px;
  }

  .card p {
    color: var(--grey);
    font-size: 13px;
    margin-bottom: 40px;
  }

  .card img {
    width: 60px;
    display: block;
    margin-left: auto;
  }

  .attribution { 
    font-size: 11px; 
    text-align: center; 
    margin-top: 40px;
  }
  
  .attribution a { 
    color: hsl(228, 45%, 44%); 
  }

  @media (max-width: 1100px) {
    .card-container {
      flex-direction: column;
    }
    
    .card {
      width: 100%;
    }
  }