style.css

*{
	
	font-family: "Lucida Sans", "Lucida Sans Regular", "Lucida Grande",
	  "Lucida Sans Unicode", Geneva, Verdana, sans-serif;
  }
  :root {
    --white: #f9f9f9;
    --dark: black;
    --green-light: #00df5e;
    --yellow: #f7df1e;
    --gray: #828282;
    --gray-200: #333333;
    --gray-400: #212121;
    --gray-400-rgb: 33, 33, 33;
    --alpha: 0.8;
  }
  ul{
    list-style-type: none;
}

a{
    text-decoration: none;
    color: var(--white);
}
body {
	 
  
  background-image: url("img/background.jpg");
  background-size: cover;
  background-repeat: no-repeat;
  background-attachment: fixed;
  background-position: center;
  text-align: center;
  color: white;
}

header{

    display: flex;
    justify-self: center;
    width: 100%;
    height: 60px;
    margin-top: 40px;
    top: 0;
    margin-bottom: 83px;
    position: sticky;
    background-color: rgba(var(--gray-400-rgb), var(--alpha));
}
header .content{
    width: 100%;
    height: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    
    
}
header .content span.logo{
    font-size: 23px;
    font-weight: 700;
    margin-left: 30px;
    

}

header .content ul{
    display: flex;
    justify-content: space-between;
    gap: 60px;
    font-size: 20px;

}
header .content ul li{
    cursor: pointer;
}
img.logo {
	display: block;
	margin-top: 20px;
	margin-left: auto;
	margin-right: auto;
	width: 80px;
	height: 80px;
}


table.container {
	
	position: relative;
	border-spacing: 0;
	border: 4px solid #000000;
	border-collapse: collapse;
	display: none;
	color: #686868;
    font-family: Arial, sans-serif;
    font-weight: bold;
    margin-top: 1em;
	background-color: #ffbce2;
}

td.cell {
	border: 2px dotted #000000;
	padding: 0;
	cursor: context-menu;
}

td.emptyCell {
	border: 2px dotted #000000;
	padding: 0;
	cursor: pointer;
}

#t0x2, #t0x5, #t1x2, #t1x5, #t2x5,
#t3x2,#t3x5, #t4x2, #t4x5, #t5x2, #t5x5,
#t6x2, #t6x5, #t7x2, #t7x5, #t8x2, #t8x5 {
	border-right: 3px solid #000000;
}

#t2x0, #t2x1, #t2x3, #t2x4, #t2x6, #t2x7,
#t5x0, #t5x1, #t5x3, #t5x4, #t5x6, #t5x7 {
	border-bottom: 3px solid #000000;
}

#t2x2, #t2x5, #t2x8, #t5x2, #t5x5, #t5x8 {
	border-bottom: 3px solid #000000;
	border-right: 3px solid #000000;
}

.inner td {
	width: 60px;
	height: 60px;
	text-align: center;
	font-size: 2.0em;
}

.inner td:hover {
	background-color:#f2e5ee;
}

.inner td.selected {
	background-color:#ffbce2;
}

.mistakeScreen {
	position: absolute;
	width: 300px;
	height: 300px;
	top:50%;
    left:50%;
    margin:-70px 0 0 -150px;
	display: none;
	background-color: #6e802f;
	-moz-border-radius: 20px;
	-webkit-border-radius: 20px;
	-o-border-radius: 20px;
	-ms-border-radius: 20px;
	border-radius: 20px;
	cursor: context-menu;
	z-index: 1000;
}

.mistakeText {
	text-align: center;
	padding: 65px;
	line-height: 40px;
	font-size: 25px;
	color: #ffffff;
    font-family: Arial, sans-serif;
    font-weight: bold;
    cursor: pointer;
}

.winScreen {
	position: absolute;
	width: 500px;
	height: 500px;
	top:50%;
    left:50%;
    margin:-170px 0 0 -250px;
	display: none;
	background-color: #e2525f;
	-moz-border-radius: 20px;
	-webkit-border-radius: 20px;
	-o-border-radius: 20px;
	-ms-border-radius: 20px;
	border-radius: 20px;
	cursor: context-menu;
	z-index: 1000;
}

.winText {
	text-align: center;
	padding: 100px;
	line-height: 70px;
	font-size: 50px;
	color: #ffffff;
    font-family: Arial, sans-serif;
    font-weight: bold;
    cursor: context-menu;
}

#sudokuPuzzle {
	position: relative;
}

.formbutton {
	position: relative;
	background: #689fce;
	display: inline-block;
	padding: 8px;
	color: #fff;
	text-decoration: none;
	font-family: Arial, sans-serif;
    font-weight: bold;
	line-height: 1;
	-moz-border-radius: 5px;
	-webkit-border-radius: 5px;
	border-radius: 5px;
	cursor: pointer; 
	margin-top: 3em;
}

#numPad {
	position: absolute;
	width: 154px;
	height: 80px;
	display: none;
	background-color: #689fce;
	-moz-border-radius: 20px;
	-webkit-border-radius: 20px;
	-o-border-radius: 20px;
	-ms-border-radius: 20px;
	border-radius: 20px;
	cursor: pointer;
	z-index: 500;
}

.padNumbers {
	text-align: center;
	padding: 6px;
	line-height: 40px;
	font-size: 20px;
	color: #ffffff;
    font-family: Arial, sans-serif;
    font-weight: bold;
    cursor: pointer;
}

#numPad span:hover {
	color: #e2525f;
}


	.footer {
		padding: 1rem 0;
		color: #fff;
		text-align: center;
		letter-spacing: 1px;
	  }