* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    outline: none;
  }
  
  body {
    width: 100%;
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
    overflow: hidden;
    background: linear-gradient(#b6810e, #e9e64c);
  }
  
  .app {
    background: #fff;
    padding: 20px;
    width: 600px;
    margin: 0 auto;
    box-shadow: 0 1px 30px 0 rgba(0,0,0,0.14), 0 0px 0px 0 rgba(0,0,0,.12), 0 0px 0px 0px rgba(0,0,0,.3);
    border-radius: 10px;
  }
  
  .app__header {
    padding: 20px;
    text-align: center;
  }
  
  .app__content {
    display: flex;
    position: relative;
    align-items: center;
    justify-content: center;
  }
  
  .app__footer {
    padding: 20px;
    display: flex;
    flex-direction: column;
    align-items: center;
  }
  
  .input {
    display: flex;
    flex-direction: column;
    margin-bottom: 10px;
  }
  
  .input label {
    display: inline-block;
    max-width: 100%;
    margin-bottom: 3px;
    color: #acacac;
    font-family: GothamPro,sans-serif;
    font-size: .8rem;
    font-weight: normal;
    line-height: 1.2rem;
  }
  
  .input input {
    display: block;
    width: 100%;
    max-height: 2.8rem;
    padding: .8rem 1rem;
    font-size: inherit;
    font-family: inherit;
    font-weight: inherit;
    line-height: 1.4;
    color: #000;
    background: #fff none;
    border: 1px solid #999;
    border-radius: 5px;
  }
  
  .game {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1px solid #ccc;
    background: #ccc;
    min-height: 300px;
    min-width: 300px;
    max-width: 300px;
    max-height: 300px;
  }
  
  .hide {
    display: none!important;
  }
  
  .btn {
    position: absolute;
    z-index: 1;
    display: inline-block;
    padding: 1rem 2.3rem;
    margin-bottom: 0;
    font-weight: normal;
    font-family: GothamPro, sans-serif;
    font-size: 1rem;
    line-height: 1.3rem;
    text-align: center;
    white-space: nowrap;
    vertical-align: middle;
    touch-action: manipulation;
    cursor: pointer;
    user-select: none;
    background: #9ff195;
    color: #3f3f3f;
    border: none;
    border-radius: 2.8rem;
    transition: transform .2s ease-in-out,box-shadow .2s ease-in-out,-webkit-transform .2s ease-in-out,-webkit-box-shadow .2s ease-in-out;
    will-change: transform;
  }
  
  .btn:disabled {
    background: #ccc!important;
    border: 1px solid #ccc;
    color: #000;
    cursor: not-allowed;
  }
  
  .btn:active {
    transition: transform .1s ease-in-out,box-shadow .1s ease-in-out!important;
    transform: none!important;
    box-shadow: none!important;
  }
  
  .btn:hover {
    box-shadow: 0 6px 16px 0 rgba(0,0,0,.2);
    transform: translateY(-1px);
  }