可以通过调整宽度来设置两边的线
<div class="modelTitle"> <span>大家好</span> </div>
.modelTitle {
width: 100%;
display: table;
white-space: nowrap;
text-align: center;
background: transparent;
font-weight: 500;
color: #fff;
font-size: 14px;
margin: 8px 0;
vertical-align: middle;
position: relative;
}
.modelTitle::before,
.modelTitle::after {
content: "";
width: 50%;
height: 1px;
border-top: 1px solid #e8eaec;
display: table-cell;
top: 50%;
transform: translateY(50%);
}
.modelTitle span {
display: inline-block;
padding: 0 10px;
}