a {
    color: black;
    text-decoration: none;
}

a:hover {
    color: grey;    
    text-decoration-style: solid;
}

a:active {
    color: silver;
}

blockquote {
    width: 512px;
    font-style: italic;
    margin-bottom: 32px;
}

body {
    text-align: left;
    font-family: "Times New Roman", "Noto Serif CJK JP";
    font-size: 16px;
    background-color:#e3e3e3;
}

#container_1 {
    margin: auto auto 64px;
    width: 512px;
}

#container_2 {
    margin: auto auto 64px;
    width: 640px;
}

#date {
    margin-left: 24px;
}
    
footer {
    text-align: right;
}

h1 {
    text-align: center;
    margin: 32px auto auto;
}

h3 {
    margin: 48px auto auto;
}

h4 {
    text-align: center;
    margin: 48px auto auto;
}

h5 {
    font-size: 18.72px;
    margin: 32px auto auto;
}

hr {
    margin: 32px auto auto;
}

img {
    display: block;
    margin: auto;
    border-style: groove;
    filter: grayscale(100%);
}

.mb0 {
    margin-bottom: 0;
}

.mt0 {
    margin-top: 0;
}

mjx-help {
    display: none ! important;
}

.mjx-selected {
    outline: none ! important;
}

.right {
    display: inline;
    float: right;
    clear: right;
}

::selection {
    color: grey;
}

#summarium {
    width: 512px;
    margin-left: 24px;
    margin-right: 24px;
}

table {
    margin: auto;
}

table, th, td {
    border: 1px solid;
    border-collapse: collapse;
    padding: 10px;
}

td:hover {
    background-color: silver;
}