math.css

.eq {
    font-family: serif;
    display: inline-flex;
    flex-direction: row;
    align-items: center;
    justify-content: center;
}

.eq sup, span.var sup {
    font-size: 60%;
}

.group {
    display: inline-flex;
    flex-direction: row;
    align-items: center;
    justify-content: center;
}

.eq.full_line {
    display: flex;
    font-size: 125%;
}

.frac {
    display: flex;
    flex-direction: column;
    margin-left: 0.1em;
    margin-right: 0.1em;
    align-items: stretch;
    justify-content: center;
}
.frac > :first-child {
    border-bottom: 0.75px solid black;
    padding-bottom: 0.1em;
}
.frac > :last-child {
    border-top: 0.75px solid black;
    padding-top: 0.1em;
}

.var {
    display: inline;
    font-style: italic;
    font-family: serif;
    margin-left: 0.05em;
    margin-right: 0.05em;
}

p > span.var, p>span.sym, p>.num {
    font-family: serif;
    margin-left: 0.05em;
    margin-right: 0.05em;
}

.num {
    display: inline;
    font-style: normal;
}

.sym {
    display: inline;
    margin-left: 0.2em;
    margin-right: 0.2em;
}

.paren {
    display: flex;
    flex-direction: row;
    align-items: center;
    justify-content: center;
}

.paren::before {
    content: "(";
}
.paren::after {
    content: ")";
}
.paren.tall {
    margin-left: 0.1em;
    margin-right: 0.1em;
}
.paren.tall::before, .paren.tall::after {
    transform: scale(1, 3.2);
    padding-bottom: 0.1em;
}

/*
.paren_tall {
    border-left: 2px solid black;
    border-right: 2px solid black;
    border-radius: 5px;
}
*/

.isolate::before {
    content: "\200a";
    font-size: 50%;
}
.isolate::after {
    content: "\200a";
    font-size: 50%;
}

table {
    border-spacing: 0.5em;
    border-collapse: separate;
}