float-css 在 div 图像旁边重叠

Question

当屏幕到达40rem 时，我的徽标和导航分别向左和向右浮动。然而，它与下一个包含背景图像的div 重叠。我尝试设置边距，但这只是将徽标/导航和图像移到页面下方。

@import url('https://fonts.googleapis.com/css?family=Raleway:300,400,700,900');
* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: 'Raleway', sans-serif;
  text-align: center;
}

img {
  max-width: 100%;
  height: auto;
  width: auto;
}

.container {
  width: 95%;
  max-width: 70em;
  margin: 0 auto;
}

.clearfix::after,
section::after {
  content: '';
  display: block;
  clear: both;
}


/* typography
    ================= */

.unstyled-list {
  margin: 0;
  padding: 0;
  list-style-type: none;
}


/* header
    ================= */

header {
  position: relative;
  left: 0;
  right: 0;
  margin: 1em;
}

.logo {
  width: 200px;
  height: 40px;
}

nav ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

nav li {
  display: inline-block;
  margin: 1em;
  padding: 0.125em;
}

nav a {
  font-weight: 900;
  text-decoration: none;
  text-transform: uppercase;
  font-size: .8rem;
  padding: .75em;
  color: #DDD;
}


/* home-main
    ================= */

.home-main {
  background-image: url('../manjitcss/img/manjit-main.png');
  background-size: cover;
  background-position: center;
  padding: 10em 0;
}

@media(min-width:40rem) {
  .logo {
    float: left;
    margin-top: .5em;
  }
  nav {
    float: right;
  }
}

@media(min-width:60rem) {
  .logo {
    width: 250px;
    height: 50px;
  }
  nav {
    margin-top: .5em;
  }
  nav a {
    font-size: 1.04em;
  }
}

<header>
  <img src="../manjitcss/img/logo.jpg" alt="Foo logo" class="logo">

  <nav>
    <ul>
      <li><a href="">Home</a></li>
      <li><a href="">About Me</a></li>
      <li><a href="">Contact</a></li>
    </ul>
  </nav>
</header>

<section class="home-main">
  <div class="container">
  </div>
</section>

Answer 1

您的 css 中有 .clearfix，但您还没有将它们应用到 header 其您正在浮动的内容。

将课程添加到header - 请参见下面的演示：

@import url('https://fonts.googleapis.com/css?family=Raleway:300,400,700,900');
* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: 'Raleway', sans-serif;
  text-align: center;
}

img {
  max-width: 100%;
  height: auto;
  width: auto;
}

.container {
  width: 95%;
  max-width: 70em;
  margin: 0 auto;
}

.clearfix::after,
section::after {
  content: '';
  display: block;
  clear: both;
}


/* typography
================= */

.unstyled-list {
  margin: 0;
  padding: 0;
  list-style-type: none;
}


/* header
================= */

header {
  position: relative;
  left: 0;
  right: 0;
  margin: 1em;
}

.logo {
  width: 200px;
  height: 40px;
}

nav ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

nav li {
  display: inline-block;
  margin: 1em;
  padding: 0.125em;
}

nav a {
  font-weight: 900;
  text-decoration: none;
  text-transform: uppercase;
  font-size: .8rem;
  padding: .75em;
  color: #DDD;
}


/* home-main
================= */

.home-main {
  background-image: url('../manjitcss/img/manjit-main.png');
  background-size: cover;
  background-position: center;
  padding: 10em 0;
}

@media(min-width:40rem) {
  .logo {
    float: left;
    margin-top: .5em;
  }
  nav {
    float: right;
  }
}

@media(min-width:60rem) {
  .logo {
    width: 250px;
    height: 50px;
  }
  nav {
    margin-top: .5em;
  }
  nav a {
    font-size: 1.04em;
  }
}

<header class="clearfix">
  <img src="http://placehold.it/50x50" alt="Foo logo" class="logo" />
  <nav>
    <ul>
      <li><a href="">Home</a></li>
      <li><a href="">About Me</a></li>
      <li><a href="">Contact</a></li>
    </ul>
  </nav>
</header>

<section class="home-main">
  <div class="container">
   container
  </div>
</section>

Answer 2

当您使用 float 时，请尝试在父级上使用 overflow 属性。当浮动离开其父级时。或者你也可以使用clearfix。

Answer 3

这是浮动的问题。您可以使用 clearfix 或为 .home-main 应用浮动，如下所示

@media(min-width:40rem) {
      .logo {
        float: left;
        margin-top: .5em;
      }
      nav {
        float: right;
      }
     .home-main{
        width: 100%;
        float: left;
      }
    }