* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: Arial, sans-serif;
    background-color: #222;
    color: #eee;
}

.wrapper {
    display: flex;
    min-height: 100vh;
}

.sidebar {
    background-color: #333;
    width: 250px;
    padding: 1rem;
}

.sidebar h2 {
    margin-bottom: 1rem;
}

.sidebar ul {
    list-style: none;
}

.sidebar li {
    cursor: pointer;
    padding: 0.5rem;
}

.sidebar li:hover {
    background-color: #444;
}

.main {
    flex-grow: 1;
    padding: 1rem;
}

.title {
    margin-bottom: 1rem;
}

.chat-area {
    background-color: #333;
    padding: 1rem;
    border-radius: 5px;
    max-height: 500px;
    overflow-y: auto;
}

.message {
    display: flex;
    margin-bottom: 1rem;
}

.message:last-child {
    margin-bottom: 0;
}

.message .user {
    font-weight: bold;
    margin-right: 0.5rem;
}

.message.user1 .user {
    color: #4caf50;
}

.message.user2 .user {
    color: #2196f3;
}

.chat-container {
    background-color: #333;
    padding: 1rem;
    border-radius: 5px;
    max-height: 500px;
    display: flex;
    flex-direction: column-reverse;
    overflow-y: auto;
}

.input-area {
    background-color: #444;
    color: #eee;
    margin-top: 1rem;
    padding: 0.5rem 1rem;
    border-radius: 5px;
    text-align: center;
}

li.active {
    background-color: #555;
    color: #fff;
}