*{
	margin: 0;
	padding: 0;
	box-sizing: border-box;	
}
.logo{
	margin: 50px;
	height: 50px;
	width: auto;
}
h1, h2, h3{
	text-align: center;
}
.wrapper{
	display: flex;
	flex-flow: column nowrap;
	align-items: center;
	margin: 0 auto;	
}
.tables{
	display: flex;
	width: 650px;
}
.multiplication{
	display: block;
	width: 150px;
	border-spacing: 0;
	margin-top: 15px;
	margin-bottom: 15px;
}
.multiplication td:last-child{
	width: 42px;
}
.hundred{
	display: block;
	width: 500px;
	border-spacing: 0;
	margin-top: 15px;
	margin-bottom: 15px;
	cursor: pointer;
}
th,
td {
    border: 1px solid;
}
th {
  background-color: #04AA6D;
  color: white;
}
th,
td {
	border: 1px solid grey;
	user-select: none;
}
td {
	text-align: center;
    padding: 5px 10px;
    border-top-width: 0;
    border-left-width: 0;
}
td:first-child{
    border-left-width: 1px;
}
tr:first-child td{
    border-top-width: 1px;
}button{
	display: block;
	margin-top: 20px;
	margin-bottom: 20px;
	width: 100px;
	height: 50px;
	font-size: 14px;
	border: 4px double;
	border-radius: 20px;
	background: black;
	color: white;
	visibility: hidden;
}
.problem{
	margin-top: 50px;
}
.img{
	display: block;
	height: 50px;
	width: 50px;
	background-size: cover;
}
.solution{
	margin-bottom: 30px;
}
footer{
	text-align: center;
	margin: 50px;
}