Code Playground

<!DOCTYPE html>
<html lang="en">
<head>
 <meta charset="UTF-8">
 <meta http-equiv="X-UA-Compatible" content="IE=edge">
 <meta name="viewport" content="width=device-width, initial-scale=1.0">
 <title>Document</title>
</head>
<body>
 <input type="radio" id="x1-input" name="radiox" /> x1
<input type="radio" id="x2-input" name="radiox" /> x2
<input type="radio" id="x3-input" name="radiox" /> x3
<input type="radio" id="x4-input" name="radiox" checked /> x4
<input type="radio" id="x5-input" name="radiox" /> x5
<input type="radio" id="x6-input" name="radiox" /> x6
<input type="radio" id="x7-input" name="radiox" /> x7
 
<input type="radio" id="y1-input" name="radioy" /> y1
<input type="radio" id="y2-input" name="radioy" /> y2
<input type="radio" id="y3-input" name="radioy" /> y3
<input type="radio" id="y4-input" name="radioy" checked /> y4
<input type="radio" id="y5-input" name="radioy" /> y5
<input type="radio" id="y6-input" name="radioy" /> y6
<input type="radio" id="y7-input" name="radioy" /> y7

@charset "UTF-8";
@import url(https://fonts.googleapis.com/css?family=Nunito+Sans:300,400,600,700,800);
*,
:after,
:before {
  box-sizing: border-box;
  padding: 0;
  margin: 0;
}
$blk: #581845;
$none: rgba(#fff, 0);
$grid: 8vh;
html,body {
  height: 100%;
  font-size: 1.5vh;
  text-align: center;
  margin: 0;
  background: #9cec5b;
  font-family: sans-serif;
}
div, div u, div > u:before, label, .sig {
  aspect-ratio: 1/1;
  width: $grid;
}
div > u:before, label, label:before, label:hover, label:focus {
  transition: all 0.25s ease-in-out;
}
div, div > u:before, label, label:before{
  position: absolute;
  inset: 0;
  margin: auto;
}
div > u:before, label:before{
  color: $blk;
}

// grid
div {
  display: flex;
  flex-wrap: wrap;
  width: calc(#{$grid} * 7);
  transform: translate3d(0, -($grid * 1.25), 0);
  u { 
    box-shadow: 0 0 1px $blk;
    &:nth-of-type(odd) {
      background: rgba($blk, 0.1);
    }
  }
  & > u {
    text-decoration: none;
    position: relative;
    &:before {
      font-size: $grid;
      content: "♟";
      transform: scale(0);    
    }
  }
}

// buttons
label {
  transform: translate3d(0, 0, 0) scale(.1);
  top: auto;
  bottom: ($grid + 3);
  background: lighten($blk, 90);
  border-radius: 50%;
  color: $none;
  filter: brightness(1) drop-shadow(0 0.2rem 0 rgba($blk, 0.5));
  cursor: pointer;
  &:hover, &:focus {
    filter: brightness(0.9) drop-shadow(0 0.1rem 0 rgba($blk, 0.5));
    &:before {
      transform: scale(1.3);
    }
  }
  &:before {
    content: "\2191";
    font-size: $grid;
  }
}

//movement 
@for $i from 1 through 8 { // x & y loops
  #x#{$i}-input:checked ~ {
    #x#{$i - 1}-label { // left
      transform: translate3d(-#{$grid}, 0, 0) rotate(-90deg) scale(1);
    }
    #x#{$i + 1}-label { // right
      transform: translate3d(#{$grid}, 0, 0) rotate(90deg) scale(1);
    }
  }
  #y#{$i}-input:checked ~ {
    #y#{$i + 1}-label { // down
      transform: translate3d(0, #{$grid}, 0) rotate(180deg) scale(1);
    }
    #y#{$i - 1}-label { // up
      transform: translate3d(0, -#{$grid}, 0) scale(1);
    }
  }
}
@for $x from 1 through 8 {
  body:has(#x#{$x}-input:checked) {
    @for $y from 1 through 8 {
      &:has(#y#{$y}-input:checked) {
        $yn1: ($y - 1);
        div > u:nth-of-type(#{$yn1 * 7 + $x}):before {
            transform: scale(1);
        }
      }
    }
  }
}

//logo 
.sig {
  width: 4em;
  background: linear-gradient(45deg, $blk 25%, $none 25%), linear-gradient(135deg, $blk 25%, $none 25%), linear-gradient(45deg, $blk 25%, $none 25%), linear-gradient(135deg, $blk 25%, $none 25%), linear-gradient(45deg, $blk 25%, $none 25%), linear-gradient(135deg, $blk 25%, $none 25%), linear-gradient(45deg, $blk 25%, $none 25%), linear-gradient(135deg, $blk 25%, $none 25%);
  background-position: -0.1em -2.8em, -0.1em 1.2em, -0.1em -1em, -0.1em 2.99em, 2.3em -1.8em, 2.3em 0, 2.3em 0, 2.3em 1.8em;
  background-repeat: no-repeat;
  position: absolute;
  left: 0;
  top: -.7em;
  transform: scaleY(0.6) scale(0.7);
  border-radius: 0.5em;
  overflow: hidden;
}

Frontend Forever App