JSFiddle - React, Tailwind, and code Playground

HTML

<head lang="Eng">
    <meta charset="UTF-8">
    <title>test </title>
</head>
<body>
    <div class="menubar" id="hey">
    <div class="buttons">
    
    
        <a class="menuitem" id="firstmenuitem" href="./buy_sell.html">Buy & Sell</a>
        <a class="menuitem" href="./exchange.html">Exchange</a>
        <a class="menuitem" href="./events.html">Events</a>
        <div id="delimeter"></div>
    </div>
        <button class="festa" id="login_button">Register</button>
    </div>
</body>

CSS

body {
    background-color: #323642;
}

.menubar {
    justify-content: center;
    display: flex;
    flex-direction: row;
    background-color: #272a33;
    margin-top: -10px;
    margin-left: -10px;
    margin-right: -10px;
    align-items: center;
    height: 100%;

}
.menuitem {
    padding: 11px;
    padding-top: 17px;
    padding-left: 29px;
    font-size: 22px;
    font-family: "Ostrich Sans";
    color: #ee5f95;
    text-decoration: none;

}

#login_button {
    margin-top: 2px;
    border-radius: 5px;
    background-color: #ee5f95;
    width: 100px;
    height: 34px;
    text-align: center;
    border: none;
    font-family: "Ostrich Sans";
    font-size: 22px;
    color: white;
    line-height: 33px;
    transition: 0.7s;
    justify-content: flex-end;
}

.buttons {
  flex: 9;
  justify-content: center;
    display: flex;
    flex-direction: row;
}
.festa {
  flex: 1;
}

#login_button:hover {
    width: 110px;
    background-color: #ae466d;
    transition: 0.7s;
}