* {
    box-sizing: border-box;
}

.form-container {
    background-color: #ddd;
    margin: 0 auto;
    width: 500px;
    padding: 10px;
}

.form-container input[type="text"] {
    display: block;
    width: 100%;
    padding: 5px;
    border-radius: 3px;
    border: 1px solid grey;
}

.form-container .form-item {
     margin-bottom: 15px;
}
.form-container [type="submit"] {
    background-color: blue;
    padding: 10px;
    border: 1px solid blue;
    text-transform: uppercase;
    color: white;
}