main.js

 var firebaseConfig = {
    apiKey: "AIzaSyDXYLXRVqf9QM6Bg9BwsSAifSAh01-cpXE",
    authDomain: "contactform-f6785.firebaseapp.com",
    projectId: "contactform-f6785",
    storageBucket: "contactform-f6785.appspot.com",
    messagingSenderId: "852640140610",
    appId: "1:852640140610:web:7c000cb953a4459972ccdb",
    measurementId: "G-M3QV6L42K2"
  };
 

// Initialize Firebase
  firebase.initializeApp(firebaseConfig);
  firebase.analytics();

// Reference messages collection
var messagesRef = firebase.database().ref('messages');

// Listen for form submit
document.getElementById('contactForm').addEventListener('submit', submitForm);

// Submit form
function submitForm(e){
  e.preventDefault();

  // Get values
  var name = getInputVal('name');
  var name = getInputVal('secondname');
 
  var message = getInputVal('message');

  // Save message
  saveMessage(name,secondname,message );

  // Show alert
  document.querySelector('.alert').style.display = 'block';

  // Hide alert after 3 seconds
  setTimeout(function(){
    document.querySelector('.alert').style.display = 'none';
  },3000);

  // Clear form
  document.getElementById('contactForm').reset();
}

// Function to get get form values
function getInputVal(id){
  return document.getElementById(id).value;
}

// Save message to firebase
function saveMessage(name,secondname,message){
  var newMessageRef = messagesRef.push();
  newMessageRef.set({
    name: name,
    secondname: secondname,
    message:message
  });
}




        var checkbox = document.querySelector('input[name=theme]');

        checkbox.addEventListener('change', function() {
            if(this.checked) {
                trans()
                document.documentElement.setAttribute('data-theme', 'dark')
            } else {
                trans()
                document.documentElement.setAttribute('data-theme', 'light')
            }
        })

        let trans = () => {
            document.documentElement.classList.add('transition');
            window.setTimeout(() => {
                document.documentElement.classList.remove('transition')
            }, 1000)
        }