style.css

@font-face {
    font-family: "pixelUnicode";
    src: url("./fonts/pixel_unicode/Pixel-UniCode.ttf");
}

.title{
    margin-left: 5px;
}

.desc{
    text-align : center;
    margin-top : 20px;
    margin-bottom : 20px;
    padding: 20px;
    background-color: #D0D0D0;
}

body {
    font-family: "pixelUnicode";
    font-size  : 20px;
    /* font-size  : 2em; */
    font-weight: 600;
    letter-spacing: 1px;
    align-items: center;
    align-content: center;
}

.page {
    max-width: 800px;
    margin: auto;
}

.header {
    background-color: #2E2E2E;
    padding: 10px;
    color: white;
    margin-bottom: 10px;
}

.header > a{
    float: right;
    margin-right: 10px;
    margin-left: 10px;
    color: white;
}
.header > a:hover, a:visited, a:link, a:active
{
    color: white;
    text-decoration: none;
}
.header > a:hover{
    color: #BBB;
}

.header > .right{
    float: right;
}

.container{
    width  : 100%;
    display: flex;
    flex-wrap: wrap;
}

.container > .item{
    min-width: 0;
    min-width: 360px;
    width: 100%;
    flex: 50%;
    align-items: center;
    align-content: center;
    text-align: center;
    margin-bottom: 20px;
}

.container > .item:hover{
    background-color: #DDD;
    cursor: pointer;
    width: 100%;
    flex: 50%;
}

.container > .item > img {
    margin-left: auto;
    margin-right: auto;
    /* margin-top: 20px; */
    display: block;
    width: 80%;
    border: 2px solid #2E2E2E;
}

.eq {
    font-size: 0.8em;
}
.frac {
    display: inline-block;
    position: relative;
    vertical-align: middle;
    letter-spacing: 0.001em;
    text-align: center;
}
.frac > span {
    display: block;
    padding: 0.1em;
}
.frac span.bottom {
    border-top: 2px solid black;
}

.unfinished{
    color: #999;
}