JSFiddle - React, Tailwind, and code Playground

HTML

<div class="readmore">
  <p>
    text / text / text / text / text / text / text / text / text / text / text / text / text / text / text / text / text
  </p>
</div>

CSS

.overflow {
  height: 120px;
  overflow: hidden;
}

JavaScript

$(document).ready(function() {
  $('.readmore').each(function() {
    if ($(this).height() >= 150) {
      var p = $('p', this),
        a = $('<a>', {
          'href': '',
          'class': 'click'
        });
      p.addClass('overflow');
      a.text('подробнее');
      $(this).append(a);
      a.click(function() {
        if (p.hasClass('overflow')) {
          p.removeClass('overflow');
          a.text('скрыть');
        } else {
          p.addClass('overflow');
          a.text('подробнее');
        }
        return false;
      });
    }
  });
});