body{
font-family:Arial;
text-align:center;
background:#222;
color:white;
}

body {
  overflow: hidden;  
  touch-action: none; 
}

.arena{
position:relative;
width:520px;
margin:auto;
}

#game{
display:grid;
grid-template-columns:repeat(8,60px);
justify-content:center;
margin:30px auto;
}

.cell{
width:60px;
height:60px;
display:flex;
justify-content:center;
align-items:center;
border:1px solid #555;
background:#333;
cursor:pointer;
font-size:20px;
}

/* LEVEL BUTTONS CENTER */
.level-select{
margin-top:20px;
display:flex;
justify-content:center;
}

.level-select button{
background:#2196F3;
margin:5px;
}

/* SUM CELLS */

.sum{
background:#111;
font-weight:bold;
cursor:default;
}

.removed{
background:#111;
color:#444;
text-decoration:line-through;
}

.wrong{
background:red;
color:white;
}

/* UNDO CHECK CENTER */

.buttons{
margin-top:20px;
display:flex;
justify-content:center;
}

/* BUTTON STYLE */

button{
padding:10px 20px;
margin:5px;
font-size:16px;
cursor:pointer;
border:none;
background:#4CAF50;
color:white;
border-radius:5px;
}

button:disabled{
background:#777;
cursor:not-allowed;
}

/* RESULT SCREEN */

.result-screen{
position:absolute;
top:0;
left:0;
width:100%;
height:100%;
background:rgba(0,0,0,0.85);

display:none;
justify-content:center;
align-items:center;
}

.result-box{
background:white;
color:black;
padding:30px;
border-radius:10px;
text-align:center;
}