Question

这是我在HTML中的代码

<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>Selection</title>
    <link rel="stylesheet" href="style.css">
      </head>
      <body >
   <div id="container"  >
  <form action="http://localhost:8084/CBGS/Allocate" method="Get">        
    <h1>College EXAM SECTION</h1>
<div id="sem">Semester:
<select name="sem">
<option value="3" >Sem3</option>
<option value="4">Sem4</option>
  <option value="5">Sem5</option>
 <option value="6">Sem6</option>
 </select>
 </div>   
   <div id="branch">Branch:         
            <select name="branch">
  <option value="IT" >IT</option>
  <option value="COMP">COMP</option>
<option value="MECH">MECH</option>
<option value="CIVIL">CIVIL</option>
<option value="EXTC">EXTC</option>
 </select>
   </div>
         <div id="exam">   
             <input type="radio" name="exam" value="R" />REGULAR<br>
  <input type="radio" name="exam" value="K"/>KT                
         </div>
 <div id="numberstudent">
    No of student
 <input type="number" name="noOfStudent" min="1" max="100">
  </div>
  < input type ="submit">

</form>
</div>         
</body>

 </html>

和样式.css是

  body
{
 margin: 0px auto;
width:700px;

    //margin:0 auto;
//margin-left:50px;
font-family:Arial, Helvetica, sans-serif;
font-size:100%; 
    color: white;
line-height:1em;
background-image: url("image/tail-middle.jpg");
    background-repeat: repeat-y;

 }


#container
{

background:url(image/newsletter-bg.gif) ;
display: block;

 border-radius:10px;
  // border:10px solid ;//#EE872A;
//background-color: yellow;
width:600px;
margin-left: auto;
margin-right: auto;
margin-top: 10%;
padding: 20px;

     }
   h1{
//color: black;
margin-left: 20px;
}

#sem , #branch, #exam,#numberstudent {
display: block;
//color: blueviolet;


}
 #branch,#sem {
 float: left;

}

#exam{
 clear: both;
 }

 #numberstudent{
 margin-left: auto;
 margin-right: auto;
  }

但是这里保证金：0自动不起作用，因为我的图像没有向中心移动，即使我使用保证金 - 左边它也不起作用，我的代码中有什么颜色，任何建议都是最受欢迎的

Answer 1

----------

     body {
       margin: 0px auto;
       width: 700px;
       font-family: Arial, Helvetica, sans-serif;
       font-size: 100%;
       color: white;
       line-height: 1em;
       background-image: url("image/tail-middle.jpg") #ccc;
       background-repeat: repeat-y;
       background-position: 50% 0;
     }
     .wrapper{
       width:100%;
       background-image:url("http://www.corelangs.com/html/html.png");
       background-repeat:no-repeat;
      }
     #container {
       background: url(image/newsletter-bg.gif);
       display: block;
       border-radius: 10px;
       /*border:10px solid ;//#EE872A;
       background-color: yellow;*/
       width: 600px;
       margin-left: auto;
       margin-right: auto;
       margin-top: 10%;
       padding: 20px;
     }
     h1 {
       //color: black;
       margin-left: 20px;
     }
     #sem,
     #branch,
     #exam,
     #numberstudent {
       display: block;
       //color: blueviolet;

     }
     #branch,
     #sem {
       float: left;
     }
     #exam {
       clear: both;
     }
     #numberstudent {
       margin-left: auto;
       margin-right: auto;
     }

<html>

<head>
</head>

<body>
  <div class="wrapper">
  <div id="container">
    <form action="http://localhost:8084/CBGS/Allocate" method="Get">
      <h1>College EXAM SECTION</h1>
      <div id="sem">Semester:
        <select name="sem">
          <option value="3">Sem3</option>
          <option value="4">Sem4</option>
          <option value="5">Sem5</option>
          <option value="6">Sem6</option>
        </select>
      </div>
      <div id="branch">Branch:
        <select name="branch">
          <option value="IT">IT</option>
          <option value="COMP">COMP</option>
          <option value="MECH">MECH</option>
          <option value="CIVIL">CIVIL</option>
          <option value="EXTC">EXTC</option>
        </select>
      </div>
      <div id="exam">
        <input type="radio" name="exam" value="R" />REGULAR
        <br>
        <input type="radio" name="exam" value="K" />KT
      </div>
      <div id="numberstudent">
        No of student
        <input type="number" name="noOfStudent" min="1" max="100">
      </div>
      < input type="submit">

    </form>
    </div>
  </div>
</body>

</html>

请试试这个

Answer 2

尝试在css中添加以下内容：

body{margin: 0px auto !important; width:700px;}

Answer 3

您是否尝试在正文之前使用星号（*）选择器并将边距设置为0？例如：

* {
    margin: 0;
}

Answer 4

尝试在您的CSS中添加text-align: center;。即使它不是文本，也经常需要这个属性。

身体保证金属性不起作用

4 个答案: