为什么设计的时候与正式预览的效果不一样啊_网页设计

为何设计的时候与正式预览的效果不一样啊?
设计的时候宽度正常,但预览的时候宽度全部放大了....

<HTML><HEAD><TITLE>Title</TITLE>
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H4 {
FONT-SIZE: 22pt; FONT-FAMILY: 黑体; TEXT-ALIGN: center
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H5 {
FONT-SIZE: 16pt; FONT-FAMILY: 宋体,黑体; TEXT-ALIGN: center
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H6 {
FONT-WEIGHT: normal; FONT-SIZE: 18pt; TEXT-INDENT: 54pt; LINE-HEIGHT: 20pt; FONT-FAMILY: 宋体
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TABLE {
TABLE-LAYOUT: fixed; WORD-BREAK: break-all; WORD-WRAP: break-word
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WORD-BREAK: break-all; WORD-WRAP: break-word
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.datatable TH {
BORDER-RIGHT: #000000 1px solid; PADDING-RIGHT: 2px; BORDER-TOP: #000000 0px solid; PADDING-LEFT: 2px; PADDING-BOTTOM: 2px; VERTICAL-ALIGN: middle; BORDER-LEFT: #000000 0px solid; PADDING-TOP: 2px; BORDER-BOTTOM: #000000 1px solid; HEIGHT: 35px
}
.datatable TD {
BORDER-RIGHT: #000000 1px solid; PADDING-RIGHT: 2px; BORDER-TOP: #000000 0px solid; PADDING-LEFT: 2px; PADDING-BOTTOM: 2px; VERTICAL-ALIGN: middle; BORDER-LEFT: #000000 0px solid; PADDING-TOP: 2px; BORDER-BOTTOM: #000000 1px solid; HEIGHT: 35px
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</STYLE>

<META content="MSHTML 6.00.2900.5583" name=GENERATOR></HEAD>
<BODY>
<CENTER style="TEXT-ALIGN: center">
<TABLE class=datatable cellSpacing=0 cellPadding=0 width=589>
  <TBODY>
  <TR>
    <TD colSpan=7>一、项目及申报单位情况 </TD></TR>
  <TR>
    <TD align=middle colSpan=2>项目名称 </TD>
    <TD colSpan=5> </TD>
  </TR>
  <TR>
    <TD align=middle colSpan=2>计划类别 </TD>
    <TD colSpan=5> </TD>
  </TR>
  <TR style="HEIGHT: 38.05pt">
    <TD style="HEIGHT: 38.05pt" align=middle colSpan=2>行业分类 </TD>
    <TD style="HEIGHT: 38.05pt" colSpan=2> </TD>
    <TD style="HEIGHT: 38.05pt" align=middle colSpan=2>项目起止年限 </TD>
    <TD style="HEIGHT: 38.05pt"> </TD>
  </TR>
  <TR>
    <TD align=middle colSpan=2>项目承担单位 </TD>
    <TD colSpan=5> </TD>