JSFiddle - React, Tailwind, and code Playground

by functionalcss

HTML

<div id="1">I_want_to_make_div_width_equal_to_this_word</div>
<div id="2">I_want_to_make_div_width_equal_to_this_word
    <br/>and_anther_word_in_next_line</div>
<div id="id3"><span>I_want_to_make_div_width_equal_to_this_word</span> <span> and_anther_word_in_next_line</span></div>

CSS

div {
    display: inline-block;
    background-color:pink;
    margin-bottom:5px;
    width: auto;
}

#id3 {
    float: left;
}