Electro - Subscription form using Contact Form 7

form.html

<div class="input-group">[text* your-email class:form-control placeholder "Enter your email address"]<span class="input-group-btn">[submit class:btn class:btn-secondary "Sign Up"]</span></div>

style.css

.footer-newsletter .wpcf7-form-control[type="email"] {
    border-top-left-radius: 1.571em;
    border-bottom-left-radius: 1.571em;
}

.footer-newsletter .wpcf7-submit[type="submit"] {
    background-color: #333e48;
    color: #fff;
    border-top-right-radius: 1.571em !important;
    border-bottom-right-radius: 1.571em !important;
}