After looking at some answers I made the margin and padding of the div element 0 but still it does not make any changes to page! What's the reason behind this ?Can someone explain pls!.
<div style="margin:0px ; padding:0px; background-color:Grey">
<h1 style=" color:Orange ; text-align:center" id="title">Product Survey Form</h1>
</div>
<p style="color:blue ; text-align:center" id="description">After your every purchase from Serex technologies , we like to have a survey from <br> our customers in order to improves our services </p> 
<form id="survey-form" style="text-align:center">
   <label for="name" id="name-label">Name:</label>
  <input type="text" id="name" placeholder="First Name" required>
  <br>
<br>
   <label for="email" id="email-label">E-mail:</label>
  <input type="email" id="email" placeholder="Email" required>
  <br>
  <br>
   <label for="number" id="number-label">Age:</label>
  <input type="number" id="number" min="00" max="200" placeholder="Age">
  <br><br>
  <label for="dropdown" id="number-label">Gender:</label>
  <input list="dropdown" placeholder="Choose">
  <datalist id="dropdown">
   <option value="Male">
   <option value="Female">
   <option value="Others">
     </datalist>
  <p>What do you think about our service?</p>
  
     <label for="Excellent"> 
  <input id="Excellent" value="Excellent" type="radio" name="reviews">Excellent</label>
    <label for="ItsOkay!"> 
  <input id="ItsOkay!" value="Its Okay!" type="radio" name="reviews">Its Okay!</label>
     <label for="Hastobeimproved!"> 
  <input id="Hastobeimproved!" value="Has to be improved!" type="radio" name="reviews">Has to be improved!</label>
  <br><br>
  <p>Where have you heard about us?</p>
    <label><input type="checkbox" value="Newspapers " name="adverts"> Newspapers</label>
  <label><input type="checkbox" value="Relatives" name="adverts"> Relatives</label>
  <label><input type="checkbox" value="Television"name="adverts"> Television</label>
  <p>Additional Comments : </p>
  <textarea id="w3review" name="w3review" rows="4" cols="50" placeholder="Enter text here">
     </textarea>
  <br><br>
  <button type="submit" id="submit">Submit</button>
  
  
     
     
  
  
</form>