Question

每当我尝试为ul元素使用id元素选择器时，我遇到了问题。当我使用当前注释掉的代码时

/*#wrapper h1, h2, ul {
        text-align: center;
        font-weight: bold;
        padding: 10px 0;
    }*/

我的嵌套下拉菜单变得不合适，但它不应该这样做，因为我的导航栏甚至没有包含在包装器中。

* {
  margin: 0;
  padding: 0;
}

html,
body {
  margin: 0;
  padding: 0;
  height: 100%;
  width: 100%;
}

body {
  padding: 0;
  margin: 0;
  font-family: 'Lato', Arial, sans-serif;
}

header {
  background-color: #595959;
  color: #fff;
  padding-top: 30px;
  min-height: 90px;
  border-bottom: 3px solid #FFD700;
}

header .banner {
  float: left;
}

header .banner h1 {
  margin: 0;
}

header nav {
  float: right;
  margin-top: 10px;
}

header ul {
  float: left;
}

header li {
  float: left;
  position: relative;
  width: 150px;
  list-style: none;
}

header a {
  display: block;
  text-decoration: none;
  font-size: 16px;
  padding: 5px 15px;
  color: #fff;
  border: 2px solid black;
  background: #595959;
  font-weight: bold;
}

header a:hover {
  color: #FFD700;
}

header ul ul {
  position: absolute;
  left: 0;
  top: 100%;
  visibility: hidden;
  opacity: 0;
}

header ul ul ul {
  left: 100%;
  top: 0;
}

header li:hover,
header li:hover li,
header li li:hover,
header li li:hover li,
header li li li:hover {
  background: rgba(89, 89, 89, 0.9);
  transition-duration: 0.5s;
}

header li:hover>ul {
  visibility: visible;
  opacity: 1;
}


/*#wrapper h1, h2, ul {
	text-align: center;
	font-weight: bold;
	padding: 10px 0;
}*/

<!DOCTYPE html>

</head>

<body>
  <header>
    <div id="banner-container">
      <div class="banner">
        <h1>A-Level</h1>
        <nav>
          <ul>
            <li><a href="home.php">Home</a></li>
            <li><a href="#">A-level</a>
              <ul>
                <li><a href="#">Maths</a>
                  <ul>
                    <li><a href="mathsPLC.php">PLC</a></li>
                    <li><a href="revisionMaths.php">Revision</a></li>
                    <li><a href="mathsPapers.php">Exam Papers</a></li>
                  </ul>
                </li>
                <li><a href="#">Physics</a>
                  <ul>
                    <li><a href="physicsPLC.php">PLC</a></li>
                    <li><a href="revisionPhysics.php">Revision</a></li>
                    <li><a href="physicsPapers.php">Exam Papers</a></li>
                  </ul>
                </li>
                <li><a href="#">Computer Science</a>
                  <ul>
                    <li><a href="computingPLC.php">PLC</a></li>
                    <li><a href="revisionComputing.php">Revision</a></li>
                    <li><a href="computingPapers.php">Exam Papers</a></li>
                  </ul>
                </li>
              </ul>
            </li>
            <li><a href="index.php">TimeTable</a></li>
            <li><a href="logout.php">Logout</a></li>
          </ul>
        </nav>
  </header>
</body>

Answer 1

通过定义＆＃39; h1，h2＆amp; UL＆＃39;在#wrapper中，#wrapper中的那些元素将获得您正在定义的CSS。要在#wrapper中使用它们，请使用#wrapper h1，#wrapper h2等。

id特定元素选择器影响外部id元素

1 个答案: