style.css

.board {
    width: 380px;
    height: 360px;
    position: relative;
}

.cell {
    position: absolute;
    overflow: hidden;
}

.flex-container {
  display: flex;
  flex-direction: row;
  position: relative;
}

.center-flex-container {
  display: flex;
  flex-direction: column;
  max-width: 380px;
}

.left-inner-flex-container {
  display: flex;
  flex-direction: column;
  width: 150px;
}

div > .left-inner-flex-container {
  text-align: center;
}

.left-inner-flex-container table {
  width: 100%;
}

.right-inner-flex-container {
  display: flex;
  flex-direction: column;
  width: 100px;
}

.solution-flex-container {
  display: flex;
  flex-direction: column;
  flex-shrink: 5;
  height: 360px;
  overflow: scroll;
}

 /* The Modal (background) */
.modal-background {
  display: none; /* Hidden by default */
  position: fixed; /* Stay in place */
  z-index: 1; /* Sit on top */
  left: 0;
  top: 0;
  width: 100%; /* Full width */
  height: 100%; /* Full height */
  overflow: auto; /* Enable scroll if needed */
  background-color: rgb(0,0,0); /* Fallback color */
  background-color: rgba(0,0,0,0.1); /* Black w/ opacity */
}

/* Modal Content/Box */
.modal-content {
  display: none;
  z-index: 2;
  position: relative;
  background-color: #fefefe;
  padding: 20px;
  border: 1px solid #888;
}

/* The Close Button */
.close {
  color: #aaa;
  float: right;
  font-size: 14px;
  font-weight: bold;
}

.close:hover,
.close:focus {
  color: black;
  text-decoration: none;
  cursor: pointer;
}

.helpPage {
  display: none;
}

#solveModal {
  width: 50%;
}

#illegalPositionModal {
  width: 100%;
}