HTML 问题 - 第一个 table 在很长的间隔后开始

Question

根据屏幕截图，请指导我如何从页面顶部开始 table 标题。

分享下面代码的一些摘录。

此外，@media 查询在 Iphone 中无法正常工作。我签入了一个 android 设备，它非常有用。我试过 Iphone 7.

  #emails {
  font-family: "Trebuchet MS", Arial, Helvetica, sans-serif;
  border-collapse: collapse;
  width: 100%;
}

#emails td,
#emails th {
  border: 1px solid #ddd;
  padding: 8px;
}

#emails tr:nth-child(even) {
  background-color: #f2f2f2;
}

#emails tr:hover {
  background-color: #ddd;
}

#emails th {
  padding-top: 12px;
  padding-bottom: 12px;
  text-align: left;
  background-color: #4CAF50;
  color: white;
}

#emails2 {
  font-family: "Trebuchet MS", Arial, Helvetica, sans-serif;
  border-collapse: collapse;
  width: 100%;
}

#emails2 td,
#emails th {
  border: 1px solid #ddd;
  padding: 8px;
}

#emails2 tr:nth-child(even) {
  background-color: #f2f2f2;
}

#emails2 tr:hover {
  background-color: #ddd;
}

#emails2 th {
  padding-top: 12px;
  padding-bottom: 12px;
  text-align: left;
  background-color: #4CAF50;
  color: white;
}


/* 
    Max width before this PARTICULAR table gets nasty
    This query will take effect for any screen smaller than 760px
    and also iPads specifically.
    */

@media only screen and (max-width: 760px),
(min-device-width: 768px) and (max-device-width: 1024px) {
  /* Force table to not be like tables anymore */
  #emails2 table,
  #emails2 thead,
  #emails2 tbody,
  #emails2 th,
  #emails2 td,
  #emails2 tr {
    display: block;
  }
  /* Hide table headers (but not display: none;, for accessibility) */
  #emails2 th {
    position: absolute;
    top: -9999px;
    left: -9999px;
  }
  #emails2 tr {
    border: 1px solid #ccc;
  }
  #emails2 td {
    /* Behave  like a "row" */
    border: none;
    border-bottom: 1px solid #eee;
    position: relative;
    padding-left: 50%;
  }
  #emails2 td:before {
    /* Now like a table header */
    position: absolute;
    /* Top/left values mimic padding */
    top: 6px;
    left: 6px;
    width: 45%;
    padding-right: 10px;
    white-space: nowrap;
  }
  /*
     Label the data
     */
  #emails2 td:nth-of-type(1):before {
    content: "Domain";
  }
  #emails2 td:nth-of-type(2):before {
    content: "Email";
  }
  #emails2 td:nth-of-type(3):before {
    content: "Login";
  }
  #emails2 td:nth-of-type(4):before {
    content: "User";
  }
  #emails2 td:nth-of-type(5):before {
    content: "Disk Quota";
  }
  #emails2 td:nth-of-type(6):before {
    content: "Disk Used";
  }
  #emails2 td:nth-of-type(7):before {
    content: "Used Percentage";
  }
  #emails2 td:nth-of-type(8):before {
    content: "Delete";
  }
  #emails2 td:nth-of-type(9):before {
    content: "Change Password";
  }
}

input[type=text],
input[type=password] {
  font-family: "Trebuchet MS", Arial, Helvetica, sans-serif;
  padding: 6px 10px;
  margin: 3px 0;
  box-sizing: border-box;
}

input[type=button],
input[type=Submit],
input[type=reset] {
  font-family: "Trebuchet MS", Arial, Helvetica, sans-serif;
  background-color: #4CAF50;
  border: none;
  color: white;
  padding: 6px 10px;
  text-decoration: none;
  margin: 3px 2px;
  cursor: pointer;

<pre>
  <style>...</style>
  <title>...</title>
  <meta/>
  <meta/>
<table id="emails">
  <tr class="tableheader">
    <th align="center"><u>User Dashboard</u></th>
  </tr>
</table>

</pre>

Answer 1

根据 your screenshot，您的 table-s 在 pre 标签内。 pre 标记在源 HTML 文件中保留换行符（默认情况下）并显示它们。

在您的 HTML 代码中，在您的第一个 table 之前有许多换行符（可能在 style 内部和 title 之后以及多个 meta 标记), 它们会导致 table.

上方出现白色间隙

解决方案：不要将元素放在 pre 标签内。

HTML 问题 - 第一个 table 在很长的间隔后开始

HTML issue - The first table starts after a long gap

html

css

head

document-body