Wordpress post_content — как можно проще урезать количество символов?

.mainpostcontent{position:relative; max-height:100px; overflow:hidden;}
.mainpostcontent:before{content:""; position:absolute; left:0; bottom:0; width:100%;
height:30px;
/* Permalink - use to edit and share this gradient: https://colorzilla.com/gradient-editor/#ffffff+0,ffffff+100&0+0,1+99 */
background: -moz-linear-gradient(top, rgba(255,255,255,0) 0%, rgba(255,255,255,1) 99%, rgba(255,255,255,1) 100%); /* FF3.6-15 */
background: -webkit-linear-gradient(top, rgba(255,255,255,0) 0%,rgba(255,255,255,1) 99%,rgba(255,255,255,1) 100%); /* Chrome10-25,Safari5.1-6 */
background: linear-gradient(to bottom, rgba(255,255,255,0) 0%,rgba(255,255,255,1) 99%,rgba(255,255,255,1) 100%); /* W3C, IE10+, FF16+, Chrome26+, Opera12+, Safari7+ */
filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#00ffffff', endColorstr='#ffffff',GradientType=0 ); /* IE6-9 */
}