JSFiddle - React, Tailwind, and code Playground

HTML

<div class="fixed-cont">
<ul class="t_inject_container">
    <li class="t_inject_row">
        <ul class="menu">
            <li id="LI_4">
                <button class="add_button t_intect_button">
                    +
                </button>
            </li>
            <li>
                <button class="minimize_button t_intect_button">
                    m
                </button>
            </li>
        </ul>
    </li>
    <li>
        <ul class="content_selection_container">
            <li>
                <form name="search_form" class="search_form">
                    <input type="text" name="search_input" class="search_bar" />
                    <input type="submit" value="🔍" class="search_button" name="search_button" />
                </form>
            </li>
            <li id="LI_14">
                <button class="content_selection_button">
                    My Timeline
                </button>
            </li>
            <li>
                <button class="content_selection_button">
                    relevent
                </button>
            </li>
            <li>
                <button class="content_selection_button">
                    mentions
                </button>
            </li>
        </ul>
    </li>
</ul>
</div>

CSS

/*------------------------------------------------------------------------------------*/
 /*--Entypo Font---*/
/*------------------------------------------------------------------------------------*/
@font-face {
    font-family: 'EntypoRegular';
    src: url('font/entypo.eot');
    src: url('font/entypo.eot?#iefix') format('embedded-opentype'),
         url('font/entypo.woff') format('woff'),
         url('font/entypo.ttf') format('truetype'),
         url('font/entypo.svg#EntypoRegular') format('svg');
    font-weight: normal;
    font-style: normal;
}

@font-face {
    font-family: 'EntypoSocial';
    src: url('font/entypo-social.eot');
    src: url('font/entypo-social.eot?#iefix') format('embedded-opentype'),
         url('font/entypo-social.woff') format('woff'),
         url('font/entypo-social.ttf') format('truetype'),
         url('font/entypo-social.svg#EntypoRegular') format('svg');
    font-weight: normal;
    font-style: normal;
}

  /*------------------------------------------------------------------------------------*/
 /*----Main Page---*/
/*------------------------------------------------------------------------------------*/
.t_inject_container
{
    background-color:grey;
    margin: 0;
    padding: 0;
}
.t_inject_container > li {
    display: inline-block;
}

ul{
    list-style: none;
}

 * {
    -webkit-box-sizing: border-box;
       -moz-box-sizing: border-box;
            box-sizing: border-box;
    border-radius:5px;
}

.menu {
    background-color:lightblue;
    border-radius:5px;
    margin: 1px;
    padding: 2px;
}

.t_intect_button {
    background-color:blue;
    display:block;
    height: 50px;
    width: 50px;
    margin: 5px;
    font-size: 20px;
    color: white;
    border: 0;   
}

.minimize_button{
    height: 20px;
    width: 20px;
    margin: 2px;
    font-size: 12px;
}

 /*-------------------------------------------------------------------------------------*/
 /*Selection...