document.addEventListener('DOMContentLoaded', () => {
    const chatMessages = document.getElementById('chat-messages');
    const chatForm = document.getElementById('chat-form');
    const messageInput = document.getElementById('message-input');

    chatForm.addEventListener('submit', (e) => {
        e.preventDefault();
        const messageText = messageInput.value.trim();
        if (messageText === '') return;

        appendMessage('user', messageText);
        messageInput.value = '';

        // Simulate bot response
        setTimeout(() => {
            const botResponse = 'Searching for "' + messageText + '"... I have found 3 critical vulnerabilities. [Citation: Vendor API]. Would you like to see the details?';
            appendMessage('bot', botResponse);
        }, 1200);
    });

    function appendMessage(sender, text) {
        const messageWrapper = document.createElement('div');
        messageWrapper.classList.add('message', sender);

        const messageBubble = document.createElement('div');
        messageBubble.classList.add('message-bubble');
        messageBubble.textContent = text;

        messageWrapper.appendChild(messageBubble);
        chatMessages.appendChild(messageWrapper);
        chatMessages.scrollTop = chatMessages.scrollHeight;
    }
    
    // Initial bot message
    setTimeout(() => {
        appendMessage('bot', 'Welcome to the Intelligent IT Vendor Knowledge Integration System (IIVKIS). How can I help you today?');
    }, 500);
});