php - File generates line break only when included -

this file below working alone menu.php, when include in file using

  <?php include("menu.php") ?> 

it generates line break. why don't understand, tried several times, not solved. so, please me guys , girls.

<style> /* menu style starts*/ nav ul li:hover > ul {     display: block; } nav ul {     background: maroon;     background: linear-gradient(top, maroon 0%, #800000 100%);     background: -moz-linear-gradient(top, maroon 0%, #800000 100%);     background: -webkit-linear-gradient(top, maroon 0%,#800000 100%);     list-style: none;     display: inline-table;     position: relative;     padding: 0 15px;     box-shadow: 0px 0px 20px #888888; } nav ul:after {     content: "";     clear: both;     display: block; } nav ul li {     float: left; } nav ul li:hover {     background: #4b545f;     background: linear-gradient(top, black 0%, #5f6975 40%);     background: -moz-linear-gradient(top, black 0%, #5f6975 40%);     background: -webkit-linear-gradient(top, black 0%,#5f6975 40%); } nav ul li:hover {     color: #fff; } nav ul li {     display: block;     padding: 10px 38px;     text-decoration: none;     color: white;     font-size: 19px;     font-weight: bold; } nav ul ul {     display: none;     background: #5f6975;     border-radius: 0px;     padding: 0;     position: absolute; top: 100%; } nav ul ul li {     float: none;      border-top: 1px solid #6b727c;     border-bottom: 1px solid #575f6a;     position: relative; } nav ul ul li {     padding: 10px 40px;     color: white;     font-size: 12px;     font-weight: bold; } nav ul ul li a:hover {     background: #4b545f; } nav ul ul ul {     position: absolute; left: 100%; top:0; } /* menu style ends*/ </style>  <div align="center"      style="height: 100px; color: #ffffff; background-color: #0033cc;">     <font size="12" style="z-index:; margin-bottom:0px;">         open public library     </font>     <br />     <font size="4">         it's still under process, coming full facility     </font> </div>  <nav align=center>     <ul>         <li><a href="index.php">                 <!--img src="images/home_icon.png"/-->home             </a>         </li>         <li><a href="aboutus.php">about us</a></li>         <li><a href="user.php">user</a>             <ul>                 <li><a href="#">login</a>                     <ul>                         <li><a href="guest.php">guest</a></li>                         <li><a href="member.php">member</a></li>                         <li><a href="admin.php">administrator</a></li>                     </ul>                 </li>                 <li><a href="register.php">registration</a></li>             </ul>         </li>         <li><a href="book.php">book</a>             <ul>                 <li><a href="book_content.php">insert</a></li>                     <li><a href="#">update</a></li>                     <li><a href="show.php">show</a></li>                     <li><a href="#">search</a></li>             </ul>         </li>         <li><a href="contactus.php">contact us</a>             <ul>                 <li><a href="feedback.php">give feedback</a></li>                 <li><a href="contactus.php">see contacts</a></li>             </ul>         </li>         <li><a href="register.php">register</a></li>     </ul> </nav> 

if using utf-8 encoding, save file utf-8 without bom