JSFiddle - React, Tailwind, and code Playground

HTML

<nav id="testMenu">
    <div class="border top"></div>
    <div class="border bottom"></div>
    <div class="border left"></div>
    <div class="border right"></div>
    <button class="c-hamburger c-hamburger--htx"> <span>toggle menu</span>

    </button>
    <ul id="yellowMenu">
        <li><a href="">PROJECTS</a>

        </li>
        <li><a href="">ABOUT</a>

        </li>
        <li><a href="">SERVICE</a>

        </li>
        <li><a href="">CONTACT</a>

        </li>
    </ul>
</nav>

CSS

ul, li {
    list-style: none;
}
#yellowMenu {
    background: #fafd37;
    font-size: 2em;
    text-align: center;
    position: absolute;
    left: 0;
    top: 18px;
    right: 0;
    bottom: 0;
    height: 100%;
    display: none;
}
#yellowMenu a {
    color: black;
    text-decoration: none;
    width: 100%;
    height: 2em;
    display: block;
    line-height: 2.1;
    font-family:'FF_Super_Grotesk';
    font-weight: normal;
    font-style: normal;
    transition: background-color 2s ease;
}
#yellowMenu a:hover {
    color: #e0e0d4;
    background: rgba(182, 182, 157, 0.7);
}
/* Body border */

/* https://www.youtube.com/watch?v=HbkOzrpmhUc https://css-tricks.com/body-border/ */
 body {
    padding: 0px;
}
.border {
    position: fixed;
    background: #f9f8f3;
}
.top, .bottom {
    left: 0;
    right: 0;
    height: 50px;
}
.top {
    top: 0;
}
.bottom {
    bottom: 0;
}
.right, .left {
    top: 0;
    bottom: 0;
    width: 50px;
}
.right {
    right: 0;
}
.left {
    left: 0;
}
/* End of -->> Body border */

/* Nav */
 .c-hamburger {
    display: block;
    position: fixed;
    left: 0px;
    bottom: 0px;
    overflow: hidden;
    top: 0;
    margin: 0;
    padding: 0;
    width: 50px;
    height: 50px;
    font-size: 0;
    text-indent: -9999px;
    -webkit-appearance: none;
    -moz-appearance: none;
    appearance: none;
    box-shadow: none;
    border-radius: none;
    border: none;
    cursor: pointer;
    -webkit-transition: background 0.3s;
    transition: background 0.3s;
    z-index: 5;
}
.c-hamburger:focus {
    outline: none;
}
.c-hamburger span {
    display: block;
    position: absolute;
    top: 25px;
    left: 12px;
    right: 12px;
    height: 2px;
    background: #262626;
}
.c-hamburger span::before, .c-hamburger span::after {
    position: absolute;
    display: block;
    left: 0;
    width: 100%;
    height: 2px;
    background-color: #262626;
    content:"";
}
.c-hamburger span::before {
    top: -7px;
}
.c-hamburger span::after {
  ...

JavaScript

(function () {

        "use strict";

        var toggles = document.querySelectorAll(".c-hamburger");

        for (var i = toggles.length - 1; i >= 0; i--) {
            var toggle = toggles[i];
            toggleHandler(toggle);
        };

        function toggleHandler(toggle) {
            toggle.addEventListener("click", function (e) {
                e.preventDefault();
                (this.classList.contains("is-active") === true) ? this.classList.remove("is-active") : this.classList.add("is-active");
            });
        }
    })();