头歌-CSS入门

四川师范大学CSS 头歌

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_慢漫漫慢

6937人浏览 · 2023-03-06 21:30:56

_慢漫漫慢 · 2023-03-06 21:30:56 发布

使用HTML/CSS实现Educoder顶部导航栏

第1关使用flex布局实现Educoder顶部导航栏容器布局

第2关实现左侧文字导航列表

第3关实现右侧功能图标排序

第4关实现左侧鼠标悬停效果与选中状态

CSS从入门到精通-文本与字体样式

第1关字体颜色、类型与大小

body {
    /*背景渐变*/
    background: -webkit-linear-gradient(left, #7ECABA, #E2FCCB);
    /* Safari 5.1 - 6.0 */
    background: -o-linear-gradient(right, #7ECABA, #E2FCCB);
    /* Opera 11.1 - 12.0 */
    background: -moz-linear-gradient(right, #7ECABA, #E2FCCB);
    /* Firefox 3.6 - 15 */
    background: linear-gradient(to right, #7ECABA, #E2FCCB);
    /* 标准的语法 */
    font: 100% PingFang SC, Verdana, Helvetica Neue, Microsoft Yahei, Hiragino Sans GB, Microsoft Sans Serif, WenQuanYi Micro Hei, sans-serif;
    /*居中页面*/
    width: 45em;
    margin: 0 auto;
}

h1,
h2 {
    /* ********** BEGIN ***********/
    font-family: PingFang SC, Verdana, Helvetica Neue, Microsoft Yahei, Hiragino Sans GB, Microsoft Sans Serif, WenQuanYi Micro Hei, sans-serif;
    /* ********** END ***********/
}

h1 {
    /* ********** BEGIN ***********/
    font-size: 2.1875em;

    /* ********** END ************/
}

h2 {
    background-color: #eaebef;
    /* ********** BEGIN ***********/
    font-size: 1.75em;
    color: #7d717c;
    /* ********** END ************/
}

h3 {
    background-color: white;
    /* ********** BEGIN ***********/
    font-size: 1.25em;
    color: green;
    /* ********** END ************/
    padding-left: 10px;
}

hr {
    height: 1px;
    border: none;
    border-top: 2px dashed #88b2d2;
}

footer {
    margin: 10px auto;
}

/* CONTENT
----------------------------------- */

.architect {
    background-color: #fff;
    padding: 1.5em 1.75em;
}

/* :::: Intro ::::: */

.intro {
    background-color: #888888;
    /* ********** BEGIN ***********/
    
    color: #fefefe;
    /* ********** END ************/
    padding: 1px 1.875em .7em;
}

.intro .subhead {
    /* ********** BEGIN ***********/
    font-size: 1.125em;
    /* ********** END ************/
}

.intro p {
    font-size: 1.0625em;
}

/* :::: chapter Descriptions ::::: */

.chapter p {
    font-size: .9375em;
}

img {
    border-radius: 8px;
}

/* :::: Links :::: */

a:link {
    color: #e10000;
}

a:visited {
    color: #b44f4f;
}

a:hover {
    color: #f00;
}

.intro a {
    color: #fdb09d;
}

.intro a:hover {
    color: #fec4b6;
}

第2关字体粗细与风格

body {
    /*背景渐变*/
    background: -webkit-linear-gradient(left, #7ECABA, #E2FCCB);
    /* Safari 5.1 - 6.0 */
    background: -o-linear-gradient(right, #7ECABA, #E2FCCB);
    /* Opera 11.1 - 12.0 */
    background: -moz-linear-gradient(right, #7ECABA, #E2FCCB);
    /* Firefox 3.6 - 15 */
    background: linear-gradient(to right, #7ECABA, #E2FCCB);
    /* 标准的语法 */
    font: 100% PingFang SC, Verdana, Helvetica Neue, Microsoft Yahei, Hiragino Sans GB, Microsoft Sans Serif, WenQuanYi Micro Hei, sans-serif;
    /*居中页面*/
    width: 45em;
    margin: 0 auto;
}

h1,
h2 {
    /* 设置h1, h2 的font-family*/
    font-family: PingFang SC, Verdana, Helvetica Neue, Microsoft Yahei, Hiragino Sans GB, Microsoft Sans Serif, WenQuanYi Micro Hei, sans-serif;
    /* ********** BEGIN ***********/
    font-weight: normal;
    /* ********** END ***********/
}

h1 {
    /* 设置h1元素为 35px 的字体大小 */
    font-size: 2.1875em;
    /* 35px/16px */
}

h2 {
    background-color: #eaebef;
    /* 设置h2元素的字体颜色为：#7d717c */
    color: #7d717c;
    /* 使用em的方式设置h2元素为 28px 的字体大小 */
    font-size: 1.75em;
    /*28px/16px */
}

h3 {
    background-color: white;
    /* 使用em的方式设置h3元素为 20px 的字体大小 */
    font-size: 1.25em;
    /* 设置h3元素的字体颜色为：green */
    color: green;
    padding-left: 10px;
}

hr {
    height: 1px;
    border: none;
    border-top: 2px dashed #88b2d2;
}

/* 子选择器 */

em,
a:link,
.intro .subhead {
    font-weight: bold;
}

footer {
    /* ********** BEGIN ***********/
    font-weight: light;
    font-style: italic;
    /* ********** END ***********/
    margin: 10px auto;
}

footer a {
    font-style: normal;
}

/* CONTENT
----------------------------------- */

.architect {
    background-color: #fff;
    padding: 1.5em 1.75em;
}

/* :::: Intro ::::: */

.intro {
    background-color: #888888;
    /* 设置 .intro 类元素的字体颜色为 #fefefe */
    color: #fefefe;
    padding: 1px 1.875em .7em;
}

.intro .subhead {
    /* 使用em的方式设置 `.intro .subhead ` （intro类下得subhead子类）为 18px 的字体大小。 */
    font-size: 1.125em;
}

.intro p {
    font-size: 1.0625em;
}

/* :::: chapter Descriptions ::::: */

.chapter p {
    font-size: .9375em;
}

img {
    border-radius: 8px;
}

/* :::: Links :::: */

a:link {
    /* 设置 a:link 元素的字体颜色为 #b44f4f */
    color: #e10000;
}

a:visited {
    color: #b44f4f;
}

a:hover {
    color: #f00;
}

.intro a {
    color: #fdb09d;
}

.intro a:hover {
    color: #fec4b6;
}

第3关文本装饰与文本布局

body {
    /*背景渐变*/
    background: -webkit-linear-gradient(left, #7ECABA, #E2FCCB);
    /* Safari 5.1 - 6.0 */
    background: -o-linear-gradient(right, #7ECABA, #E2FCCB);
    /* Opera 11.1 - 12.0 */
    background: -moz-linear-gradient(right, #7ECABA, #E2FCCB);
    /* Firefox 3.6 - 15 */
    background: linear-gradient(to right, #7ECABA, #E2FCCB);
    /* 标准的语法 */
    font: 100% PingFang SC, Verdana, Helvetica Neue, Microsoft Yahei, Hiragino Sans GB, Microsoft Sans Serif, WenQuanYi Micro Hei, sans-serif;
    /*居中页面*/
    width: 45em;
    margin: 0 auto;
}

h1,
h2 {
    font-family: PingFang SC, Verdana, Helvetica Neue, Microsoft Yahei, Hiragino Sans GB, Microsoft Sans Serif, WenQuanYi Micro Hei, sans-serif;
    font-weight: normal;
    /*********** BEGIN ***********/
    text-align: center;
    /************ END ************/
}

h1 {
    /* 设置h1元素为 35px 的字体大小 */
    font-size: 2.1875em;
    /* 35px/16px */
}

h2 {
    background-color: #eaebef;
    /* 设置h2元素的字体颜色为：#7d717c */
    color: #7d717c;
    /* 使用em的方式设置h2元素为 28px 的字体大小 */
    font-size: 1.75em;
    /*28px/16px */
}

h3 {
    background-color: white;
    /* 使用em的方式设置h3元素为 20px 的字体大小 */
    font-size: 1.25em;
    /* 设置h3元素的字体颜色为：green */
    color: green;
    padding-left: 10px;
    /*********** BEGIN ***********/
    text-align: left;
    /************ END ************/
}

p {
    text-align: justify;
}

hr {
    height: 1px;
    border: none;
    border-top: 2px dashed #88b2d2;
}

/* 子选择器 */

em,
a:link,
.intro .subhead {
    font-weight: bold;
}

footer {
    font-weight: light;
    font-style: italic;
    /* ********** BEGIN ***********/
    text-align: center;
    /* ********** END ***********/
    margin: 10px auto;
}

footer a {
    font-style: normal;
}

/* CONTENT
----------------------------------- */

.architect {
    background-color: #fff;
    padding: 1.5em 1.75em;
}

/* :::: Intro ::::: */

.intro {
    background-color: #888888;
    /* 设置 .intro 类元素的字体颜色为 #fefefe */
    color: #fefefe;
    padding: 1px 1.875em .7em;
}

.intro .subhead {
    /* 使用em的方式设置 `.intro .subhead ` （intro类下得subhead子类）为 18px 的字体大小。 */
    font-size: 1.125em;
    text-align: center;
}

.intro p {
    font-size: 1.0625em;
}

/* :::: chapter Descriptions ::::: */

.chapter p {
    font-size: .9375em;
}

.photos {
    /*********** BEGIN ***********/
    text-align: center;
    /*********** END *************/
}

img {
    border-radius: 8px;
}

/* :::: Links :::: */

/* 默认显示样式 */

a:link {
    color: #e10000;
    /*********** BEGIN ***********/
    text-decoration: none;
    /*********** END *************/
}

a:visited {
    color: #b44f4f;
}

/* 鼠标放在上面的显示样式 */

a:hover {
    color: #f00;
    /*********** BEGIN ***********/
    text-decoration: underline;
    /*********** END *************/
}

.intro a {
    color: #fdb09d;
}

.intro a:hover {
    color: #fec4b6;
}

CSS从入门到精通-背景样式

第1关背景颜色

/* ********** BEGIN ********** */
body {
    background-color: ivory;
}


/* ********** END ********** */

h1 {
    font-size: 40px;
    text-align: center;
}

p {
    font-size: 18px;
    color: grey;
    /* ********** BEGIN ********** */
    background-color: lightblue;
    /* ********** END ********** */
}

第2关背景图片

body {
    /* ********** BEGIN ********** */
    /*设置背景图片*/
    background-image:url("https://www.educoder.net/attachments/download/211106") ;

    /* ********** END ********** */
}

div {
    width: 90%;
    height: 100%;
    margin: auto;
}

第3关背景定位与背景关联

 body {
     margin-right: 200px;
     /* ********** BEGIN ********** */
     /*设置背景图片*/
    background: url("https://www.educoder.net/attachments/download/211104") no-repeat fixed right top;
     /* ********** END ********** */
 }

 div {
     width: 90%;
     height: 100%;
     margin: auto;
 }

CSS从入门到精通-基础选择器

第1关 CSS 元素选择器

<!DOCTYPE html>
<html lang="zh">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>元素选择器</title>
  <style type="text/css">
    /* ********** BEGIN ********** */
    /* 元素选择器 */
    html {
      background-color:#F0F0F0;
    }

    header {
      padding:40px;
      background-color:white;
    }


    footer {
      margin-top: 20px;
      font-size:0.6em;
      color:grey;
    }

    /* ********** END ********** */
  </style>
</head>
<body>

<div>

  <header>
    <li><a href="#chosen">精选</a></li>
    <li><a href="#news">时事</a></li>
    <li><a href="#finance">财政</a></li>
    <li><a href="#think">思想</a></li>
    <li><a href="#life">生活</a></li>
  </header>

  <div>
    <section>
      <h2>精选</h2>
      <li>精选新闻1</li>
      <li>精选新闻2</li>
      <li>精选新闻3</li>
    </section>
    <section>
      <h2>时事</h2>
      <li>时事新闻1</li>
      <li>时事新闻2</li>
      <li>时事新闻3</li>
    </section>
    <section>
      <h2>财政</h2>
      <li>财政新闻1</li>
      <li>财政新闻2</li>
      <li>财政新闻3</li>
    </section>
    <section>
      <h2>思想</h2>
      <li>思想新闻1</li>
      <li>思想新闻2</li>
      <li>思想新闻3</li>
    </section>
    <section>
      <h2>生活</h2>
      <li>生活新闻1</li>
      <li>生活新闻2</li>
      <li>生活新闻3</li>
    </section>
  </div>

  <footer>Copyright (c) News Copyright Holder All Rights Reserved.</footer>

</div>

</body>
</html>

第2关 CSS 类选择器

<!DOCTYPE html>
<html lang="zh">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>类选择器</title>
  <style type="text/css">
    /* 元素选择器 */
    html {
      background-color: #F0F0F0;
    }
    header {
      padding: 40px;
      background-color: white;
    }
    footer {
      margin-top: 20px;
      font-size: 0.6em;
      color: grey;
    }
    /* 类选择器 */
    .main {
      margin: 10px;
    }
	/* ********** BEGIN ********** */
  .newsSection {
    margin-top:20px;
    padding:20px;
    background-color:white;
  }


    /* ********** END ********** */
  </style>
</head>
<body>
<div class="main">
  <header>
    <li><a href="#chosen">精选</a></li>
    <li><a href="#news">时事</a></li>
    <li><a href="#finance">财政</a></li>
    <li><a href="#think">思想</a></li>
    <li><a href="#life">生活</a></li>
  </header>
  <!-- ********** BEGIN ********** -->
  <div class="newsSection">
  <!-- ********** END ********** -->      
    <section>
      <h2>精选</h2>
      <li>精选新闻1</li>
      <li>精选新闻2</li>
      <li>精选新闻3</li>
    </section>
    <section>
      <h2>时事</h2>
      <li>时事新闻1</li>
      <li>时事新闻2</li>
      <li>时事新闻3</li>
    </section>
    <section>
      <h2>财政</h2>
      <li>财政新闻1</li>
      <li>财政新闻2</li>
      <li>财政新闻3</li>
    </section>
    <section>
      <h2>思想</h2>
      <li>思想新闻1</li>
      <li>思想新闻2</li>
      <li>思想新闻3</li>
    </section>
    <section>
      <h2>生活</h2>
      <li>生活新闻1</li>
      <li>生活新闻2</li>
      <li>生活新闻3</li>
    </section>
  </div>
  
  <footer>Copyright (c) News Copyright Holder All Rights Reserved.</footer>
</div>

</body>
</html>

第3关 CSS id选择器

<!DOCTYPE html>
<html lang="zh">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>ID选择器</title>
  <style type="text/css">
    /* 元素选择器 */
    html {
      background-color: #F0F0F0;
    }
    header {
      padding: 40px;
      background-color: white;
    }
    footer {
      margin-top: 20px;
      font-size: 0.6em;
      color: grey;
    }

    /* 类选择器 */
    .main {
      margin: 10px;
    }
    .newsSection {
      margin-top: 20px;
      padding: 20px;
      background-color: white;
    }
    /* ********** BEIGN ********** */
    #menu {

    }
    #chosen {
      color:red;
    }
    #news {
      color:blue;
    }
    #finance {
      color:olive;
    }
    #think {
      color:green;
    }
    #life {
      color:orange;
    }
    

    /*选择menu元素下的li子元素*/
    #menu li {
      float: left;
      width: 70px;
      font-size: 1.2em;
      font-weight: lighter;
    }
    /*选择menu元素下的li子元素和li下得a子元素*/
    #menu li, li a {
      list-style: none;
      text-decoration: none;
    }
    /* ********** END ********** */
  </style>
</head>
<body>
<div class="main">
  <!-- ********** BEGIN ********** -->
  <header id="menu">
  <!-- ********** END ********** -->
    <li><a href="#chosen">精选</a></li>
    <li><a href="#news">时事</a></li>
    <li><a href="#finance">财政</a></li>
    <li><a href="#think">思想</a></li>
    <li><a href="#life">生活</a></li>
  </header>

  <div class="newsSection">
    <section>
      <h2 id="chosen">精选</h2>
      <li>精选新闻1</li>
      <li>精选新闻2</li>
      <li>精选新闻3</li>
    </section>
    <section>
      <h2 id="news">时事</h2>
      <li>时事新闻1</li>
      <li>时事新闻2</li>
      <li>时事新闻3</li>
    </section>
    <section>
      <h2 id="finance">财政</h2>
      <li>财政新闻1</li>
      <li>财政新闻2</li>
      <li>财政新闻3</li>
    </section>
    <section>
      <h2 id="think">思想</h2>
      <li>思想新闻1</li>
      <li>思想新闻2</li>
      <li>思想新闻3</li>
    </section>
    <section>
      <h2 id="life">生活</h2>
      <li>生活新闻1</li>
      <li>生活新闻2</li>
      <li>生活新闻3</li>
    </section>
  </div>
  <footer>Copyright (c) News Copyright Holder All Rights Reserved.</footer>
</div>

</body>
</html>

使用HTML/CSS实现Educoder顶部导航栏

第1关使用flex布局实现Educoder顶部导航栏容器布局

<!DOCTYPE html>
<html lang="en">

<head>
	<meta charset="UTF-8">
	<title>Educoder</title>
	<script src="https://cdn.staticfile.org/jquery/1.10.2/jquery.min.js"></script>
	<script src="step1/verify.js"></script>
</head>
<style type="text/css">
	body {
		padding: 0;
		margin: 0;
	}

	.color-white {
		color: white;
	}

	/*********** Begin ************/
	.container {
		height: 60px;
		display: flex;
		justify-content: space-between;
	}

	/*********** End ************/
</style>

<body>
	<div class="container">
		<header style="background: #24292D; min-width:1200px;">
			<div class="left-wrap color-white">左边容器</div>
			<div class="right-wrap color-white">右边容器</div>
		</header>
	</div>
</body>

</html>

第2关实现左侧文字导航列表

<!DOCTYPE html>
<html lang="en">

<head>
	<meta charset="UTF-8">
	<title>Educoder</title>
	<script src="https://cdn.staticfile.org/jquery/1.10.2/jquery.min.js"></script>
	<script src="step2/verify.js"></script>
</head>
<style type="text/css">
	body {
		padding: 0;
		margin: 0;
	}

	.container {
		min-width: 1200px;
	}

	.flex {
		display: flex;
	}

	.full-height {
		height: 100%;
	}

	header {
		background: #24292D;
		height: 60px;
		justify-content: space-between;
		padding: 0 25px;
	}

	header>div {
		height: 100%;
		display: flex;
		align-items: center;
	}

	/*********** Begin ************/
	.logo-block {
		display: flex;
		align-items: center;
		justify-content: center;
	}

	.logo {
		width: 40px;
		height: 38px;
		margin-right: 30px;
	}

	.menu-item {
		color: #ffffff;
		font-size: 16px;
		width: 64px;
		height: 100%;
		display: flex;
		align-items: center;
		margin-right: 30px;
		position: relative;
	}

	.hot {
		position: absolute;
		top: 10px;
		right: -22px;
	}

	/*********** End ************/
</style>

<body>
	<div class="container">
		<header class="flex">
			<div class="left-wrap">
				<!--********** Begin **********-->
				<div class="logo-block">
					<img src="https://data.educoder.net/images/educoder/headNavLogo.png?1526520218" class="logo">
      </div>
					<div class="menu-block full-height flex">
						<div class="menu-item"><span>实践课程</span></div>
						<div class="menu-item"><span>翻转课堂</span></div>
						<div class="menu-item"><span>实训项目</span></div>
						<div class="menu-item">
							<span>在线竞赛<img class="hot" src="https://img-blog.csdnimg.cn/2022010612112358534.png"></span>
						</div>
						<div class="menu-item"><span>教学案例</span></div>
						<div class="menu-item"><span>交流问答</span></div>
					</div>
					<!--********** End **********-->
				</div>
				<div class="right-wrap">
				</div>
		</header>
	</div>
</body>

</html>

第3关实现右侧功能图标排序

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Educoder</title>
  <script src="https://cdn.staticfile.org/jquery/1.10.2/jquery.min.js"></script>
  <script src="step3/verify.js"></script>
</head>
<style type="text/css">
  body {
    padding: 0;
    margin: 0;
  }

  .container {
    min-width: 1200px;
  }

  .flex {
    display: flex;
  }

  .full-height{
    height: 100%;
  }

  header {
    background: #24292D;
    height: 60px;
    justify-content: space-between;
    padding: 0 25px;
  }

  header > div {
    height: 100%;
    display: flex;
    align-items: center;
  }

  .logo-block{
    display: flex;
    align-items: center;
    justify-content: center;
  }

  .logo {
    width: 40px;
    height: 38px;
    margin-right: 30px;
  }

  .menu-item {
    color: #ffffff;
    font-size: 16px;
    width: 64px;
    height: 100%;
    display: flex;
    align-items: center;
    margin-right: 30px;
    position: relative;
  }

  .hot{
    position: absolute;
    top: 10px;
    right: -22px;
  }
  /*********** Begin ************/
  .icon-item{
    height: 100%;
    width: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
  }
  .user{
    width: 34px;
    height: 34px;
    margin-left: 15px;
  }
  /*********** End ************/
</style>
<body>
<div class="container">
  <header class="flex">
    <div class="left-wrap">
      <div class="logo-block">
        <img src="https://www.educoder.net/images/educoder/headNavLogo.png?1526520218" class="logo">
      </div>
      <div class="menu-block full-height flex">
        <div class="menu-item"><span>实践课程</span></div>
        <div class="menu-item"><span>翻转课堂</span></div>
        <div class="menu-item"><span>实训项目</span></div>
        <div class="menu-item"><span>在线竞赛<img class="hot" src="data:image/png;base64,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"></span></div>
        <div class="menu-item"><span>教学案例</span></div>
        <div class="menu-item"><span>交流问答</span></div>
      </div>
    </div>
    <div class="right-wrap">
      <!--********** Begin **********-->
      <div class="icon-list full-height flex">
      <div class="icon-item"><img src="https://data.educoder.net/api/attachments/411643" alt=""></div>
      <div class="icon-item"><img src="https://data.educoder.net/api/attachments/411644" alt=""></div>
      <div class="icon-item"><img src="https://data.educoder.net/api/attachments/411645" alt=""></div>
      </div>
      <img class="user" src="https://data.educoder.net/images/avatars/User/b?t=1569204859650" alt="">
      <!--********** End **********-->
    </div>
  </header>
</div>
</body>
</html>

第4关实现左侧鼠标悬停效果与选中状态

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Educoder</title>
  <script src="https://cdn.staticfile.org/jquery/1.10.2/jquery.min.js"></script>
  <script src="step4/verify.js"></script>
</head>
<style type="text/css">
  body {
    padding: 0;
    margin: 0;
  }

  .container {
    min-width: 1200px;
  }

  .flex {
    display: flex;
  }

  .full-height {
    height: 100%;
  }

  header {
    background: #24292D;
    height: 60px;
    justify-content: space-between;
    padding: 0 25px;
  }

  header > div {
    height: 100%;
    display: flex;
    align-items: center;
  }

  .logo-block {
    display: flex;
    align-items: center;
    justify-content: center;
  }

  .logo {
    width: 40px;
    height: 38px;
    margin-right: 30px;
  }

  .menu-item {
    color: #ffffff;
    font-size: 16px;
    width: 64px;
    height: 100%;
    display: flex;
    align-items: center;
    margin-right: 30px;
    position: relative;
    cursor: pointer;
  }

  .hot {
    position: absolute;
    top: 10px;
    right: -22px;
  }

  .icon-item {
    height: 100%;
    width: 48px;
    display: flex;
    align-items: center;
    cursor: pointer;
    justify-content: center;
  }

  .user {
    width: 34px;
    height: 34px;
    margin-left: 15px;
    cursor: pointer;
  }

  /*********** Begin ************/
  .menu-item:hover {
    opacity:.7;
  }
  .active {
    position:relative;
    color:#459be5;
  }
  .active:after {
    position:absolute;
    content: ' ';
    width: 14px;
    height: 2px;
    background: #459be5;
    bottom: -10px;
    left: 0;
  }
  /*********** End ************/
</style>
<body>
<div class="container">
  <header class="flex">
    <div class="left-wrap">
      <div class="logo-block">
        <img src="https://www.educoder.net/images/educoder/headNavLogo.png?1526520218" class="logo">
      </div>
      <div class="menu-block full-height flex">
        <div class="menu-item"><span class="active">实践课程</span></div>
        <div class="menu-item"><span>翻转课堂</span></div>
        <div class="menu-item"><span>实训项目</span></div>
        <div class="menu-item"><span>在线竞赛<img class="hot"
                                              src="data:image/png;base64,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"></span>
        </div>
        <div class="menu-item"><span>教学案例</span></div>
        <div class="menu-item"><span>交流问答</span></div>
      </div>
    </div>
    <div class="right-wrap">
      <div class="icon-list full-height flex">
        <div class="icon-item"><img src="https://www.educoder.net/api/attachments/411643" alt=""></div>
        <div class="icon-item"><img src="https://www.educoder.net/api/attachments/411644" alt=""></div>
        <div class="icon-item"><img src="https://www.educoder.net/api/attachments/411645" alt=""></div>
      </div>
      <img class="user" src="https://www.educoder.net/images/avatars/User/b?t=1569204859650" alt="">
    </div>
  </header>
</div>
</body>
</html>