body {
    font-family: Arial, sans-serif;
    background: #f4f4f4;
    display: flex;
    height: 100vh;
    align-items: center;
    justify-content: center;
    margin: 0;
}

.chat-container {
    width: 100%;
    max-width: 400px;
    background: #fff;
    border-radius: 15px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.chat-box {
    flex-grow: 1;
    padding: 20px;
    overflow-y: auto;
    border-bottom: 1px solid #eee;
}

.chat-form {
    display: flex;
}

#chat-input {
    flex-grow: 1;
    padding: 15px;
    border: none;
    border-top: 1px solid #eee;
}

button {
    padding: 15px;
    background: #007bff;
    color: white;
    border: none;
    cursor: pointer;
    border-top: 1px solid #eee;
}

button:hover {
    background: #0056b3;
}