Grid | Flexbox: posicione elementos na tela

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Alurinha | Cursos online</title>
    <link rel="stylesheet" href="style.css">
</head>
<body>
    <div class="grid">
        <div class="box">Ruby on Rails</div>
        <div class="box">Java</div>
        <div class="box">HTML</div>
        <div class="box">Python</div>
        <div class="box">Wordpress</div>
        <div class="box">Bootstrap</div>
        <div class="box">Java Web</div>
        <div class="box">MySQL</div>
    </div>
</body>
</html>

body {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
    font-size: 20;
}
.box{
    height: 50px;
    width: 50px;
    background-color: green;
    width: 20%;
    margin: 1%;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
}

.grid{
    display: flex;
    flex-wrap: wrap;

}

.box:nth-child(4n) {
    margin-right: 0;
}

.box:nth-child(4n + 1) {
    margin-left: 0;
}

Resultado Insira aqui a descrição dessa imagem para ajudar na acessibilidade