style.css

.chat {
    height: 400px;
    overflow-y: auto;
}
.chat-content {
    border: 1px solid #ccc;
    border-radius: 5px;
    padding-top: 10px;
}
.chat-root {
    padding: 20px;
}
.bubble {
    padding: 5px 10px;
    margin: 5px;
    border-radius: 8px;
    display: inline-block;
    font-size: 12px;
}
.mine {
    text-align: right;
}
.mine.sent .bubble {
    background-color: #c3ed7d;
}
.mine.received .bubble {
    background-color: #73a233;
}
.his.sent .bubble {
    background-color: #87e1f6;
}
.his.received .bubble {
    background-color: #418faf;
}
.message {
    padding: 5px;
    background-color: #faf8f3;
    border-top: 1px solid #ccc;
}
.chat .message:last-child {
    border-bottom: 1px solid #ccc;
}
.nav-link {
    font-size: 14px;
    text-transform: uppercase;
    color: #111;
    font-weight: 600;
}
.nav-link.active {
    color: #63b485 !important;
}