body {
    margin: 10px 18px;
    font-size: 15px;
    line-height: 22px;
    font-family: Helvetica, sans-serif, Microsoft Yahei, Arial, Lucida, Verdana;
    word-wrap: break-word;
}
a {
    color: #409eff;
    font-weight: bolder;
    text-decoration: none;
}
p {
    margin: 15px 0;
}

p:nth-child(1) {
    font-size: 18px;
    text-align: center;
    font-weight: bold;
}
underline {
    text-decoration: underline;
}

i {
    font-style: italic;
}
ol,
ul {
    padding-inline-start: 20px;
}

li {
    margin: 10px 0;
}

ul li {
    list-style-type: disc;
}

li ul li {
    list-style-type: square;
}


/* a b c */
.ll {
    list-style-type: lower-latin;
}
/* A B C */
.ul {
    list-style-type: upper-latin;
}
/* i ii iii */
.lr {
    list-style-type: lower-roman;
}
/* I II III */
.ur {
    list-style-type: upper-roman;
}