body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f5f5f5;
}

.chat-container {
    max-width: 800px;
    margin: 0 auto;
    height: 100vh;
    display: flex;
    flex-direction: column;
    background-color: white;
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.1);
}

h1 {
    background-color: #4a90e2;
    color: white;
    margin: 0;
    padding: 20px;
    text-align: center;
    font-size: 24px;
    font-weight: 600;
}

.messages-container {
    flex: 1;
    overflow-y: auto;
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.message {
    display: flex;
    flex-direction: column;
    max-width: 70%;
    padding: 12px 16px;
    border-radius: 18px;
    word-wrap: break-word;
}

.user-message {
    align-self: flex-end;
    background-color: #4a90e2;
    color: white;
}

.assistant-message {
    align-self: flex-start;
    background-color: #e9ecef;
    color: #333;
}

.system-message {
    align-self: center;
    background-color: #ffebcc;
    color: #856404;
    border: 1px solid #ffeaa7;
}

.message-role {
    font-size: 12px;
    font-weight: 600;
    margin-bottom: 4px;
    opacity: 0.7;
    text-transform: capitalize;
}

.message-content {
    font-size: 14px;
    line-height: 1.4;
}

.input-form {
    display: flex;
    padding: 20px;
    gap: 10px;
    background-color: #f8f9fa;
    border-top: 1px solid #dee2e6;
}

.message-input {
    flex: 1;
    padding: 12px 16px;
    border: 1px solid #ced4da;
    border-radius: 25px;
    font-size: 14px;
    outline: none;
    transition: border-color 0.2s ease;
}

.message-input:focus {
    border-color: #4a90e2;
    box-shadow: 0 0 0 2px rgba(74, 144, 226, 0.25);
}

.message-input:disabled {
    background-color: #f8f9fa;
    color: #6c757d;
    cursor: not-allowed;
}

.send-button {
    padding: 12px 24px;
    background-color: #4a90e2;
    color: white;
    border: none;
    border-radius: 25px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.2s ease;
    min-width: 80px;
}

.send-button:hover:not(:disabled) {
    background-color: #357abd;
}

.send-button:disabled {
    background-color: #6c757d;
    cursor: not-allowed;
}

/* Scrollbar styling */
.messages-container::-webkit-scrollbar {
    width: 8px;
}

.messages-container::-webkit-scrollbar-track {
    background: #f1f1f1;
}

.messages-container::-webkit-scrollbar-thumb {
    background: #c1c1c1;
    border-radius: 4px;
}

.messages-container::-webkit-scrollbar-thumb:hover {
    background: #a1a1a1;
}

/* Responsive design */
@media (max-width: 768px) {
    .chat-container {
        height: 100vh;
    }
    
    .message {
        max-width: 85%;
    }
    
    .input-form {
        padding: 15px;
    }
    
    h1 {
        padding: 15px;
        font-size: 20px;
    }
}