<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8">
        <link rel="stylesheet" href="style.css">
        <title>Basic JS</title>
    </head>
    <body>
        <h1 class="name">Calculator v. 1</h1>
        <div class="field">
            <label>
                <input id="firstValue" class="value-box">
            </label>
            <label>
                <select name="operation" id="operation" class="operation-box">
                    <option value="+">+</option>
            