CSS的行为非常奇怪，特别是间距

Question

我正在制作一个带有注册表单的页面，以供我的ASP.NET网站的新用户创建帐户。我已经从以下URL复制了一个响应式水平CSS表单模板：https://www.templatemonster.com/blog/responsive-css3-form-fields-tutorial。我的网站上使用此表单的页面是https://maxstechandmathsite.azurewebsites.net/Registration。如果您仔细看一下，就会清楚地看到一些样式问题。首先，我将向您展示HTML和CSS的重要部分：

HTML：

<div id="wrapper">
<form runat="server" onsubmit="return false">
<h1>Personal Information</h1>
<span style="float: right; font-size: 1.5em"><span class="red">*</span>&nbsp;Required</span>
<div class="col-4">
<label>
  Date of Birth (DOB) <span class="red">*</span>
<input type="date" required="required" placeholder="When is your date of birth?" id="dob" name="dob" tabindex="10" />
</label>
</div>
<div class="col-4">
  <label>
    Gender <span class="red">*</span>
    <select id="gender" required="required" name="gender" tabindex="11">
      <option>Male</option>
      <option>Female</option>
      <option>I do not wish to identify</option>
    </select>
  </label>
</div>
<div class="col-4 switch">
  <label>Send Text Notifications?</label>
  <center style="position:relative; padding-bottom: 8px"><input type="checkbox" class="js-switch" /></center>
</div>
<div class="col-4 switch">
  <label>Email Updates?</label>
  <center style="position:relative; padding-bottom: 8px"><input type="checkbox" class="js-switch" /></center>
</div>
<div id="BottomSection">
<br />
<h1 style="background-color: blueviolet">Login Information</h1>
<asp:CreateUserWizard ID="RegisterUser" runat="server" BackColor="#F7F7DE" BorderColor="#CCCC99" BorderStyle="Solid" BorderWidth="1px" Font-Names="Verdana" Font-Size="10pt" OnCreatedUser="CreateUserWizard1_CreatedUser">
</asp:CreateUserWizard>
<div style="text-align: center; font-size: 1.5em">
    Enter password hint for future reference:
    <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
    <br />
    <asp:CheckBox ID="CheckBox1" runat="server" />I have read and agree to the <asp:HyperLink ID="HyperLink2" runat="server" NavigateUrl="~/PrivacyPolicy.html">Privacy Policy</asp:HyperLink> &nbsp;and <asp:HyperLink ID="HyperLink1" runat="server" NavigateUrl="~/TermsOfService.html">Terms Of Service</asp:HyperLink>.</div>
<div class="col-submit">
<button class="submitbtn">Submit Form</button>
</div>
</div>
</form>
</div>

CSS：

form > div.switch > label {
   padding: 22px 20px 18px;
}

label > input {
   display: inline-block;
   position: relative;
   width: 100%;
   height: 27px;
   line-height: 27px;
   margin: 5px -5px 0;
   padding: 7px 5px 3px;
   border: none;
   outline: none;
   color: #555;
   font-family: 'Helvetica Neue', Arial, sans-serif;
   font-weight: bold;
   font-size: 14px;
   opacity: .6;
   transition: all linear .3s;
}

label > select {
   display: block;
   width: 100%;
   padding: 7px 5px 3px;
   margin: 5px -5px 0;
   color: #555;
   font-weight: 500;
   height: 35px;
   border: none;
   outline: none;
   font-family: 'Helvetica Neue', Arial, sans-serif;
   font-size: 14px;
   opacity: .6;
   transition: all linear .3s;
}

如您所见，我已经调整了原始源代码中提供的一些代码，但这只是我为更好而确定的代码，因为在我看来，它与众不同。有关完整的CSS样式表，请转到https://maxstechandmathsite.azurewebsites.net/Style/styles.css。这是我的问题：

1）没有显示h1标题，甚至没有普通的HTML文本（例如带星号（*）的文本表示该字段为必填字段，ASP.NET复选框旁边的文本），尽管显示了依靠Visual Studio的设计文件。

2）对于最下面的一行，间距和边框显然存在一些问题。出现蓝色边框，但比上面几行的蓝色边框粗，并且还有一些空白，并且底部行的每一列的高度和填充均不均匀。我已经尝试过对许多不同的padding和margin值进行调整和试验，但是仍然保持不平衡。最后，我还进行了换行（<br>），以便在表单字段和ASP.NET CreateUserWizard控件之间留出一定的空间，但也没有应用。

我们将不胜感激。谢谢！

Answer 1

1）从font-size: 0选择器中删除form，以查看标题。

form {
  display: block;
  margin: 30px;
  overflow: hidden;
  background: #fff;
  border: 3px solid #7eaf4a;
  border-radius: 5px;
  font-size: 0;         /* <- remove this */
}

2）用.col-3, .col-4和vertical-align: top更新min-height选择器，以使它们都具有相同的高度和样式。

.col-3, .col-4 { 
  border-bottom: 3px solid #0026ff;
  border-right: 3px solid #0026ff;
  background-color: #ebf442;
  vertical-align: top;
  min-height: 100px;
}

我已经对<span>Required</span>元素和媒体查询进行了一些更新，以使响应式设计正常工作，并包含上述修复程序。 下面的代码段：

@import url(http://fonts.googleapis.com/css?family=Laila:400,700);
@import url('https://fonts.googleapis.com/css?family=Damion|Muli:400,600');

html, body, div, span, applet, object, iframe, h1, h2, h3, h4, h5, h6, p, blockquote, pre, a, abbr, acronym, address, big, cite, code, del, dfn, em, img, ins, kbd, q, s, samp, small, strike, strong, sub, sup, tt, var, b, u, i, center, dl, dt, dd, ol, ul, li, fieldset, form, label, legend, table, caption, tbody, tfoot, thead, tr, th, td, article, aside, canvas, details, embed, figure, figcaption, footer, header, hgroup, menu, nav, output, ruby, section, summary, time, mark, audio, video {
  margin: 0 auto;
  text-align: center;
  font-size: 100%;
  font: inherit;
  vertical-align: baseline;
  outline: none;
  -webkit-font-smoothing: antialiased;
  -webkit-text-size-adjust: 100%;
  -ms-text-size-adjust: 100%;
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
  box-sizing: border-box;
}

html { overflow-y: scroll; }

body {
  font-family: Arial, Tahoma, sans-serif;
  background: #e2eef4;
  font-size: 62.5%;
  line-height: 1;
  padding-top: 40px;
}

.red { color: red }

input, textarea { 
  -webkit-font-smoothing: antialiased;
  outline: none; 
}

strong, b { font-weight: bold; }
em, i { font-style: italic; }

h1 {
  display: block;
  font-size: 3.1em;
  line-height: 1.45em;
  font-family: 'Laila', serif;
  text-align: center;
  font-weight: bold;
  text-shadow: 1px 1px 0 #fff;
  background-color: #ebf442;
}

/** form field **/
form {
  display: block;
  margin: 30px;
  overflow: hidden;
  background: #fff;
  border: 3px solid #7eaf4a;
  border-radius: 5px;
  /* font-size: 0; */
}

form > div > label {
  display: block;
  padding: 20px 20px 10px;
  vertical-align: top;
  font-size: 13px;
  font-weight: bold;
  text-transform: uppercase;
  color: #939393;
  cursor: pointer;
}

form > div.switch > label {
  padding: 22px 20px 18px;
}

.col-3, .col-4 { 
  border-bottom: 3px solid #0026ff !important;
  border-right: 3px solid #0026ff !important;
  background-color: #ebf442;
  vertical-align: top;
  min-height: 100px;
}

.col-4 {
  float: left;
}

label > input {
  display: inline-block;
  position: relative;
  width: 100%;
  height: 27px;
  line-height: 27px;
  margin: 5px -5px 0;
  padding: 7px 5px 3px;
  border: none;
  outline: none;
  color: #555;
  font-family: 'Helvetica Neue', Arial, sans-serif;
  font-weight: bold;
  font-size: 14px;
  opacity: .6;
  transition: all linear .3s;
}

label > select {
    display: block;
    width: 100%;
    padding: 7px 5px 3px;
    margin: 5px -5px 0;
    color: #555;
    font-weight: 500;
    height: 35px;
    border: none;
    outline: none;
    font-family: 'Helvetica Neue', Arial, sans-serif;
    font-size: 14px;
    opacity: .6;
    transition: all linear .3s;
}

.col-submit {
  text-align: center;
  padding: 20px;
}

label > input:focus, label > select:focus {
  opacity: 1;
}

/** button design based on http://codepen.io/guvootes/pen/eyDAb **/
button {
  width: 100%;
  height: 35px;
  border: none;
  border-radius: 4px;
  margin: 0 0 15px 0;
  font-size: 14px;
  color: #fff;
  font-weight: bold;
  text-shadow: 1px 1px 0 rgba(0,0,0,0.3);
  overflow: hidden;
  outline: none;
}

button.submitbtn {
  background-image: -moz-linear-gradient(#97c16b, #8ab959);
  background-image: -webkit-linear-gradient(#97c16b, #8ab959);
  background-image: linear-gradient(#97c16b, #8ab959);
  border-bottom: 1px solid #648c3a;
  cursor: pointer;
  color: #fff;
}
button.submitbtn:hover {
  background-image: -moz-linear-gradient(#8ab959, #7eaf4a);
  background-image: -webkit-linear-gradient(#8ab959, #7eaf4a);
  background-image: linear-gradient(#8ab959, #7eaf4a);
}
button.submitbtn:active {
  height: 34px;
  border-bottom: 0;
  margin: 1px 0 0 0;
  background-image: -moz-linear-gradient(#7eaf4a, #8ab959);
  background-image: -webkit-linear-gradient(#7eaf4a, #8ab959);
  background-image: linear-gradient(#7eaf4a, #8ab959);
  -moz-box-shadow: inset 0 1px 3px 1px rgba(0, 0, 0, 0.3);
  -webkit-box-shadow: inset 0 1px 3px 1px rgba(0, 0, 0, 0.3);
  box-shadow: inset 0 1px 3px 1px rgba(0, 0, 0, 0.3);
}

#BottomSection {
    background-color: #e4e4e4;
    display: block;
}

/** responsive design **/

@media(min-width: 150px) {
    form > div {
        display: inline-block;
    }

    .col-submit {
        display: block;
    }

    .col-2, .col-3, .col-4 {
        box-shadow: 1px 1px #0026ff;
        border-bottom: 1px solid #0026ff;
        border-right: 1px solid #0026ff;
    }

    .col-2 {
        width: 50%
    }

    .col-3 {
        width: 33.3333333333%
    }

    .col-4 {
        width: 25%
    }

    .col-submit button {
        width: 30%;
        margin: 0 auto;
    }
}

@media (max-width: 640px) {
    #app_body {
        padding-left: 0 !important
    }

    #main_fields div.field label, #eeoc_fields div.field label {
        float: none !important;
        width: 100% !important;
        text-align: left !important;
        display: block !important
    }

    #main_fields .field-error-msg {
        padding-left: 0 !important
    }

    #education_section .select2-container, #custom_fields .select2-container, #custom_fields div.field input[type=text], #custom_fields div.field textarea, #custom_fields div.field select, #main_fields div.field input[type=text], #main_fields div.field textarea, #eeoc_fields div.field input[type=text], #eeoc_fields div.field textarea {
        width: 100% !important;
        -webkit-box-sizing: border-box;
        -moz-box-sizing: border-box;
        box-sizing: border-box
    }

    #eeoc_fields div.field select, #custom_fields div.field select {
        width: 100% !important
    }

    .accessible #header {
        padding-right: 0
    }

    .accessible #resume_paste, .accessible #cover_letter_paste {
        margin-left: 0 !important
    }

    .accessible div.required-fields {
        bottom: auto;
        left: auto;
        right: 30px;
        top: 30px
    }

    .accessible #custom_fields .field label:not(:first-child) {
        margin-top: 15px;
        display: inline-block
    }

    .accessible #main_fields div.field textarea.paste, .accessible #eeoc_fields div.field textarea.paste {
        margin-left: 0
    }

    .accessible #main_fields .employment .field input[type='checkbox'] {
        margin-left: 0 !important
    }

    .accessible #main_fields .employment .field label.current {
        display: inline-block !important;
        width: auto !important
    }

    .accessible .filter-container select {
        width: 100% !important
    }

    .accessible .locate-me, .accessible .year {
        margin-top: 10px !important
    }

    .accessible #add_education, .accessible #add_employment {
        margin: 0 !important
    }

    .accessible .remove-background-field {
        position: absolute;
        margin: 0;
        top: -15px;
        right: 0
    }
  
  .col-4 {
    width: 100%;
  }
}

<div id="wrapper">
<form runat="server" onsubmit="return false">
  
<h1>Personal Information</h1>
  
<span style="font-size: 1.5em; position: absolute; z-index: 1; right: 40px;">
  <span class="red">*</span>
  <span>&nbsp;Required</span>
</span>

  <div class="col-4">
    <label>
      Date of Birth (DOB) <span class="red">*</span>
    <input type="date" required="required" placeholder="When is your date of birth?" id="dob" name="dob" tabindex="10" />
    </label>
  </div>

  <div class="col-4">
    <label>
      Gender <span class="red">*</span>
      <select id="gender" required="required" name="gender" tabindex="11">
        <option>Male</option>
        <option>Female</option>
        <option>I do not wish to identify</option>
      </select>
    </label>
  </div>

  <div class="col-4 switch">
    <label>Send Text Notifications?</label>
    <center style="position:relative; padding-bottom: 8px"><input type="checkbox" class="js-switch" /></center>
  </div>

  <div class="col-4 switch">
    <label>Email Updates?</label>
    <center style="position:relative; padding-bottom: 8px"><input type="checkbox" class="js-switch" /></center>
  </div>

  
<div id="BottomSection">
<br />
  
<h1 style="background-color: blueviolet">Login Information</h1>
  
<asp:CreateUserWizard ID="RegisterUser" runat="server" BackColor="#F7F7DE" BorderColor="#CCCC99" BorderStyle="Solid" BorderWidth="1px" Font-Names="Verdana" Font-Size="10pt" OnCreatedUser="CreateUserWizard1_CreatedUser">
</asp:CreateUserWizard>
<div style="text-align: center; font-size: 1.5em">
    Enter password hint for future reference:
    <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
    <br />
    <asp:CheckBox ID="CheckBox1" runat="server" />I have read and agree to the <asp:HyperLink ID="HyperLink2" runat="server" NavigateUrl="~/PrivacyPolicy.html">Privacy Policy</asp:HyperLink> &nbsp;and <asp:HyperLink ID="HyperLink1" runat="server" NavigateUrl="~/TermsOfService.html">Terms Of Service</asp:HyperLink>.</div>
<div class="col-submit">
<button class="submitbtn">Submit Form</button>
</div>
</div>
</form>
</div>