body {
	width: 100vw;
	height: 100vh;
	display: flex;
	align-items: center;
	justify-content: center;
	flex-flow: column;
	margin: 0;
	overflow: hidden;
	font-family: "Lato", sans-serif;
}

.sudoku-container {
	border: 4px solid #444444; 
	margin: 0 auto;
	position: relative;
	padding: 0 2px;
}

.sudoku-container::before, .sudoku-container::after {
	position: absolute;
	border-style: solid;
	pointer-events: none;
	content: "";
}

.sudoku-container::before {
	width: 156px;
	border-width: 0 4px;
	border-color: transparent #444444 transparent #444444; 
	top: 4px;
	left: 160px;
	bottom: 4px;
}

.sudoku-container::after {
	height: 156px;
	border-width: 4px 0;
	border-color: #444444 transparent #444444 transparent; 
	left: 4px;
	top: 160px;
	right: 4px;
}

tr:nth-child(1) td:nth-child(3) input,
tr:nth-child(1) td:nth-child(6) input {
	margin: 0 10px 0 0;
}

tr:nth-child(3) input,
tr:nth-child(6) input {
	margin: 0 0 10px 0;
}

.sudoku-container input {
	width: 40px;
	height: 40px;
	text-align: center;
	font-size: 20px;
	padding: 0;
	border: 3px #555555 solid; 
	background-color: #acacac; 
	color: #eee;
}

.sudoku-container input:focus {
	border-color: #777777; 
}

.sudoku-container input.highlight {
	background-color: #888888; 
	border-color: #888888; 
}

.sudoku-container input.disabled {
	cursor: not-allowed;
	background-color: #666666; 
	border-color: #666666; 
}

.sudoku-container input.disabled.highlight {
	background-color: #888888; 
	border-color: #888888; 
}

.sudoku-container .invalid {
	border-color: #e74c3c;
}

.sudoku-container .invalid:focus {
	border-color: #e74c3c;
}

.sudoku-container.valid-matrix {
	border-color: #19b719;
}

#controls {
	margin-bottom: 15px;
}

.btn.primary {
    margin-top: 8px;
    padding: 8px 18px;
    font-size: 1.2rem;
    cursor: pointer;
    background-color: #808080;
    color: #DDDDDD;
    transition: all 0.5s ease;
    border: none;
    border-radius: 8px;
  }
  
  .btn.primary:hover {
    background-color: #555555;
	
  }


  #timer {
    margin-top: -10px;
    padding: 8px 18px;
    font-size: 1.2rem;
    font-weight: bold;
    color: #DDDDDD;
    background-color: #808080; 
    border-radius: 8px;
    text-align: center;

}


	#timer-container
	{
		display: flex;
		align-items: center;
		gap: 5px;
	}


#playPauseBtn {
	margin-top: -10px;
    padding: 8px 12px;
    font-size: 1.2rem;
    cursor: pointer;
    background-color: #808080;
    color: #DDDDDD;
    border: none;
    border-radius: 8px;
    transition: all 0.5s ease;
	align-items: center;
}

#playPauseBtn:hover {
    background-color: #555555;
}