style.css

/* Design By Keyur Diwan */

html, body {
    background-color: rgb(196, 247, 247);
    min-width: 600px;
    font-family: monospace;
    font-size: 1.5 em;
  }

  table {
    border: 2px solid #000000;
  }

  td {
    border: 1px solid #000000;
    text-align: center;
    vertical-align: middle;  
  }

  input {
    color: rgba(26, 252, 5, 0.815);
    font-family: 'Franklin Gothic Medium', 'Arial Narrow', Arial, sans-serif;
    padding: 0;
    border: 0;
    text-align: center;
    width: 48px;
    height: 48px;
    font-size: 24px !important;
    background-color: whitesmoke;
    outline: none;
  }

  right-ans{
      color: chartreuse;
  }

  input:disabled {
    color:black;
    /* font-weight: bold; */
  font-family: 'Franklin Gothic Medium', 'Arial Narrow', Arial, sans-serif;
}

  .row-2, .row-5 {border-bottom: 2px solid #000000;}
  .row-3, .row-6 {border-top: 2px solid #000000;}
  .col-2, .col-5 {border-right: 2px solid #000000;}
  .col-3, .col-6 {border-left: 2px solid #000000;}
  .col-0 {border-left: 2px solid #000000;}
  .row-0 {border-top: 2px solid #000000;}
  .col-8 {border-right: 2px solid #000000;}
  .row-8 {border-bottom: 2px solid #000000;}

  .background-gray{
  /* background-color: hotpink; */
    background-color: rgb(222, 236, 240) !important;
  }
  
  .wrong-answer{
    color: red;
  }
  .action-container{
    margin-left: auto;
    margin-right: auto;
    display: grid;
    grid-template-rows: auto auto auto;
  }
  .actions{
    margin-left: auto;
    margin-right: auto;
    display: grid;
    grid-template-columns: auto auto auto;
    max-width: 600px;
  }
  
  .container{
    display: grid;
    grid-row: auto auto auto;

  }

  .board-container{
    margin-left: auto;
    margin-right: auto;
  }

  .footer{
    margin-right: auto;
    margin-left: auto;
    font-size: 28px;
   
  }

  .score, .submit{
    margin-left: auto;
    margin-right: auto;
    padding: 0.5em;
  }

  button:hover{
    cursor: pointer;
    background-color: lightcyan;
    border: 1px solid black;
  }
  button:disabled{
    cursor: default;
    background-color: lightcyan;
    color: black;
    font-size: 16px;
    padding: 7px;
    margin: 10px;
    border: 1px solid black;
    /* border: black; */
  }
  select, button{
    font-size: 16px;
    padding: 7px;
    margin: 10px;
    
    background-color:  lightcyan ;
    /* border: red; */
    text-align: center;
  }

  .pending{
    cursor: wait;
    pointer-events: none;
  }

  .levels, .newGame, .clearBoard{
      /* background-color: red; */
    margin: 0.5em;
  }

  #overlay {
    position: fixed; /* Sit on top of the page content */
    display: none; /* Hidden by default */
    width: 100%; /* Full width (cover the whole page) */
    height: 100%; /* Full height (cover the whole page) */
    top: 0; 
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(0,0,0,0.5); /* Black background with opacity */
    z-index: 2; /* Specify a stack order in case you're using a different order for other elements */
    cursor: wait;
  }

  #timer{
      font-size: 50px;
  }