* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}
body {
    font-family: 'Segoe UI', Arial, sans-serif;
    background: #f0f2f5;
    padding: 20px;
}
.chat-container {
    max-width: 900px;
    margin: 0 auto;
    background: #fff;
    border-radius: 10px;
    box-shadow: 0 2px 15px rgba(0,0,0,0.1);
    height: 70vh;
    overflow-y: auto;
    padding: 20px;
}
.message {
    margin: 10px 0;
    padding: 12px 18px;
    border-radius: 8px;
    max-width: 75%;
    word-wrap: break-word;
}
.message.user {
    background: #007bff;
    color: #fff;
    margin-left: auto;
    text-align: right;
}
.message.bot {
    background: #e9ecef;
    color: #333;
}
.input-area {
    max-width: 900px;
    margin: 15px auto;
    display: flex;
    gap: 10px;
}
#message {
    flex: 1;
    padding: 12px;
    border: 1px solid #ddd;
    border-radius: 6px;
    font-size: 16px;
}
button {
    padding: 12px 25px;
    background: #007bff;
    color: #fff;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 16px;
}
button:hover {
    background: #0056b3;
}
@media (max-width: 600px) {
    .chat-container, .input-area {
        width: 100%;
        padding: 10px;
    }
    .message { max-width: 85%; }
}