automatic line wrapping caused by different rendering widths? Do you render your text in Em?

post the html and css of this paragraph

(function(doc, win) {
        resizeEvt = 'orientationchange' in window ? 'orientationchange' : 'resize', //orientationchange
            recalc = function() {
                var whdef = 12 / 750; // 750,12PX
                var wH = window.innerHeight; // 
                var wW = window.innerWidth; // 
                var rem = wW * whdef; // ,FONT-SIZE
                $('html').css('font-size', rem + "px");
            };
        recalc();
        if (!doc.addEventListener) return;
        win.addEventListener(resizeEvt, recalc, false); //
        doc.addEventListener('DOMContentLoaded', recalc, false); //
    })(document, window)
    
    
     .share {
            position: fixed;
            width: 100%;
            height: 10.67rem;
            background-color: rgba(0, 0, 0, 0.6);
            display: flex;
            align-items: center;
            justify-content: space-around;
            bottom: 0;
            left: 0;
        }
        
        .share>img {
            width: 7.9rem;
            height: 7.9rem;
            margin-left: 3rem;
        }
        
        .share_text {
            /* margin-left: 1rem; */
            font-family: '';
        }
        
        .share_name {
            font-size: 2.5rem;
            color: -sharpfff;
            letter-spacing: 0.05rem;
            margin-top: 0.1rem;
            font-family: '';
            line-height: 4rem;
        }
        
       
        
        .share_sologan {
            font-size: 2rem;
            color: -sharpfff;
            line-height: 4rem;
            letter-spacing: 0.05rem;
            font-family: '';
        }
        
        .load_btn {
            display: inline-block;
            text-decoration: none;
            width: 16rem;
            height: 6.67rem;
            line-height: 6.67rem;
            text-align: center;
            font-size: 2.5rem;
            color: -sharpfff;
            background-color: -sharpa15ff7;
            border-radius: 1.67rem;
            letter-spacing: 0.08rem;
            /* margin-left: 2rem; */
        }
        
        
        
        html
        
        
         <div class="share">
        <img src="./image/logo.png" alt="">
        <div class="share_text">
            <p class="share_name">

            <p class="share_sologan">,APP!

        </div>
        <a href="-sharp" class="load_btn"></a>
    </div>