<button class="btn btn--primary">
    <i class="ri-mail-add-line"></i>
</button>
<button class="btn btn--secondary">
    <i class="ri-twitch-fill"></i>
</button>
<button class="btn btn--success">
    <i class="ri-calendar-check-line"></i>
</button>
<button class="btn btn--danger">
    <i class="ri-mail-send-fill"></i>
</button>
<button class="btn btn--warning">
    <i class="ri-mail-settings-fill"></i>
</button>
<button class="btn btn--info">
    <i class="ri-customer-service-2-fill"></i>
</button>