.square {
  width: 100px;
  height: 100px;
  background: #eee;
  font-size: 800%;
  line-height:1em;
  text-align:center;
}

#sudokuboard table, th, td {
  border: 1px solid black;
}



/*
.square {
  width: 100px;
  height: 100px;
  background: #eee;
  font-size: 800%;
  line-height:1em;
  text-align:center;
}

#sudokuboard table, th, td {
  border: 1px solid black;
}
*/

/* Style The Dropdown Button */
/*
.dropbtn {
  background-color: #4CAF50;
  color: white;
  padding: 16px;
  font-size: 16px;
  border: none;
  cursor: pointer;
}
*/
/* The container <div> - needed to position the dropdown content */
/*
.dropdown {
  position: relative;
  display: inline-block;
}
*/
/* Dropdown Content (Hidden by Default) */
/*
.dropdown-content {
  display: none;
  position: absolute;
  background-color: #f9f9f9;
  min-width: 160px;
  box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
  z-index: 1;
}

.dropdown:hover .dropdown-content {
  display: block;
}
*/
body{
  font-family: Avenir, Heveltica, sans-serif;
}
li:nth-child(n):nth-child(-n+9) {
  border-top-width: 4px;
}
li:nth-child(n+73):nth-child(-n+81) {
  border-bottom-width: 4px;
}
li:nth-child(3n) {
  border-right-width: 4px;
}
li:nth-child(9n+1) {
  border-left-width: 4px;
}
li:nth-child(n+19):nth-child(-n+27) {
  border-bottom-width: 4px;
}
li:nth-child(n+46):nth-child(-n+54) {
  border-bottom-width: 4px;
}

ul {
  display: grid;
  grid-template-columns: repeat(9, 5vw);
  grid-template-rows: repeat(9, 5vw);
  justify-content: center;
  align-content: center;
  grid-gap: 0rem;
  list-style: none;
  margin: 0 0 2vw;
  padding: 0;
  font-size: calc(2vw + 10px);
}
li {
  margin: 0;
  padding: 0;
  text-align: center;
  border: 1px solid black;
  display: flex;
  align-items: center;
  justify-content: center;
  span {
    margin-top: 0.4rem;
  }  
}

.note {
  background: #ddd;
  font-family: monospace;
  padding: 2em 5em;
  font-size: 120%;
  order: -1;
}
@supports (display:grid) {
  .note {display:none;}
}