* {
    box-sizing: border-box;
  }
  
  body {
    background-color: black;
    color: #0F3;
    text-align: center;
  }

  #intro {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh; 
    background-color: rgba(0,0,0,.7);
    z-index: 999;
  }

  #instructions {
    margin: auto;
    width: 35%;
    max-height: 70%;
    margin-top:10%;
    padding: 20px;
    background-color: rgba(0,0,111,.7);
    color: #AAFFFF;
    border: solid 2px blue;
    box-shadow: 5px 5px 10px 10px black;
    border-radius: 20px; 
    font-size: 1.2rem;
    overflow: auto;
  }

  button {
    font-size: 1.3rem;
    background-color: lightgreen;
    border-radius: 5px;
    padding-left: 15px;
    padding-right: 15px;
  }

  ul {
    text-align: left;
  }
  
  #main {
    width: 1000px;
    height: 600px;
    margin: auto;
    background: url("images/green_bricks.gif");
    border-radius: 15px;
  }
  
  #container {
    position: relative;
  }
  
  #message {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -75%);
    font-size: 2.5rem;
  }
  
  #gameboard {
    width: 850px;
    height: 450px;
    margin: 50px auto 20px auto;
  }
  
  #elements {
    display: flex;
    padding: 10px 100px 10px 50px;
    justify-content: space-evenly;
  }
  
  .score {
    display: inline-block;
    padding-top: 1px;
    font-size: 1.3rem;
    height: 40px;
    width: 150px;
  }
  
  .label {
    color: #005500;
    font-weight: 800;
    font-size: 1.7rem;
  }
  
  .output {
    background-color: black;
    border: 5px solid green;
    border-right: 5px solid lightgreen;
    border-bottom: 5px solid lightgreen;
    border-radius: 15px;
  }

  h6 {
    margin-top: 100px;
    font-size: 1rem;
    color: white;
  }