1.html

<html>
<head>
<title>CSS</title>
<link rel="stylesheet" type="text/css" href="style1.css">
</head>
<body>
<div id="abc">
    <nav>
        <ul>
          <li class="dropdown">
            <a href="javascript:void(0)" class="dropbtn">Join a Community</a>
            <div class="dropdown-content">
              <a href="cancer.html">Cancer</a>
              <a href="diabetes.html">Diabetes</a>
              <a href="aids.html">AIDS</a>
            </div>
          </li>
          <li><a href="consult.html">Consult A Doctor</a></li>
          <li><a href="aboutus.html">About Us</a></li>
          <li><a href="signin.html">Sign In</a></li>
          <li class="dropdown1">
            <a href="javascript:void(0)" class="dropbtn1">Sign Up</a>
            <div class="dropdown-content1">
              <a href="student.html">Patient</a>
              <a href="doctor.html">Doctor</a>
            </div>
          </li>
        </ul>
    </nav>
</div>
</body>
</html>