子项列表在其上空盘旋时消失

Question

我有一个水平菜单。当鼠标悬停在子元素上时，它会消失。无法单击子元素。当鼠标悬停在它上面时，我希望子元素保持不变。

.header {
    color: #FFFFFF;
    height: 60px;
    width: 100%;
    margin: auto;
}
.header_logo {
    width: 40%;
    height: 100%;
    float: left;
}
#logo {
    height: 100%;
    top: 0;
    left: 0;
    width: 50%;
}
.header_title {
    width: 60%;
    float: left;
}
#titles {
    position: absolute;
    top: 20px;
    font-family: "Times New Roman", Times, serif, Georgia;
    font-size: 97%;
    color: #B8B8B8;
}
ul {
    list-style-type: none;
}
li {
    display: inline-block;
}
a {
    text-decoration: none;
    color: inherit;
    padding: 21px 10px;
}
li a:hover {
    background-color: #666699;
}
ul li ul {
    display: none;
}
ul li:hover ul {
    display: block;
    position: absolute;
    width: 100%;
    top: 70px;
    left: 0;
    white-space: nowrap;
}
* {
    border: 0;
    margin: 0;
    padding: 0;
}
.content {
    height: 800px;
    margin: auto;
    background-color: #C0C0C0;
}
.footer {
    margin: auto;
    background-color: #000000;
}

<div class="header">
    <div class="header_logo">
        <img id="logo" src="civic-logo.jpg">
    </div>
    <div class="header_title">
        <div id="titles">
            <ul>
                <li><a href="#">PRODUCTS</a>
                    <ul>
                        <li><a href="#">CEMENT</a></li>
                        <li><a href="#">STEEL</a></li>
                        <li><a href="#">BRICKS</a></li>
                        <li><a href="#">SAND</a></li>
                    </ul>
                </li>
                <li><a href="#">CONTACT US</a> </li>
            </ul>
        </div>
    </div>
</div>
<div class="content">
</div>
<div class="footer">
</div>

Answer 1

这是因为您已完全定位了子菜单，并且距离您的父级别太远，因此您的鼠标在到达子菜单之前会离开父菜单。我已经添加了边框来向您展示。

＆＃13;

＆＃13;

.header {
    color: #FFFFFF;
    height: 60px;
    width: 100%;
    margin: auto;
}
.header_logo {
    width: 40%;
    height: 100%;
    float: left;
}
#logo {
    height: 100%;
    top: 0;
    left: 0;
    width: 50%;
}
.header_title {
    width: 60%;
    float: left;
}
#titles {
    position: absolute;
    top: 20px;
    font-family: "Times New Roman", Times, serif, Georgia;
    font-size: 97%;
    color: #B8B8B8;
}
ul {
    list-style-type: none;
}
li {
    display: inline-block;
    border: 1px solid blue;
}
a {
    text-decoration: none;
    color: inherit;
    padding: 21px 10px;
}
li a:hover {
    background-color: #666699;
}
ul li ul {
    display: none;
}
ul li:hover ul {
    display: block;
    position: absolute;
    width: 100%;
    top: 70px;
    left: 0;
    white-space: nowrap;
}
* {
    border: 0;
    margin: 0;
    padding: 0;
}
.content {
    height: 800px;
    margin: auto;
    background-color: #C0C0C0;
}
.footer {
    margin: auto;
    background-color: #000000;
}

＆＃13;

<div class="header">
    <div class="header_logo">
        <img id="logo" src="civic-logo.jpg">
    </div>
    <div class="header_title">
        <div id="titles">
            <ul>
                <li><a href="#">PRODUCTS</a>
                    <ul>
                        <li><a href="#">CEMENT</a></li>
                        <li><a href="#">STEEL</a></li>
                        <li><a href="#">BRICKS</a></li>
                        <li><a href="#">SAND</a></li>
                    </ul>
                </li>
                <li><a href="#">CONTACT US</a> </li>
            </ul>
        </div>
    </div>
</div>
<div class="content">
</div>
<div class="footer">
</div>

＆＃13;

＆＃13;

＆＃13;

您有填充，但它位于a元素上，而是需要位于li元素上。在您的子菜单li元素中添加padding-top或调整其top位置，以便它们直接位于父元素下面（也就是＆＃34;触及＆＃34;）。

以下是将菜单移至top: 40px并将填充添加到子菜单li元素的代码：

＆＃13;

＆＃13;

.header {
    color: #FFFFFF;
    height: 60px;
    width: 100%;
    margin: auto;
}
.header_logo {
    width: 40%;
    height: 100%;
    float: left;
}
#logo {
    height: 100%;
    top: 0;
    left: 0;
    width: 50%;
}
.header_title {
    width: 60%;
    float: left;
}
#titles {
    position: absolute;
    top: 20px;
    font-family: "Times New Roman", Times, serif, Georgia;
    font-size: 97%;
    color: #B8B8B8;
}
ul {
    list-style-type: none;
}
li {
    display: inline-block;
}
a {
    text-decoration: none;
    color: inherit;
    padding: 21px 10px;
}
li ul li {
    padding: 21px 10px;
}
li a:hover {
    background-color: #666699;
}
ul li ul {
    display: none;
}
ul li:hover ul {
    display: block;
    position: absolute;
    width: 100%;
    top: 40px;
    left: 0;
    white-space: nowrap;
}
* {
    border: 0;
    margin: 0;
    padding: 0;
}
.content {
    height: 800px;
    margin: auto;
    background-color: #C0C0C0;
}
.footer {
    margin: auto;
    background-color: #000000;
}

＆＃13;

<div class="header">
    <div class="header_logo">
        <img id="logo" src="civic-logo.jpg">
    </div>
    <div class="header_title">
        <div id="titles">
            <ul>
                <li><a href="#">PRODUCTS</a>
                    <ul>
                        <li><a href="#">CEMENT</a></li>
                        <li><a href="#">STEEL</a></li>
                        <li><a href="#">BRICKS</a></li>
                        <li><a href="#">SAND</a></li>
                    </ul>
                </li>
                <li><a href="#">CONTACT US</a> </li>
            </ul>
        </div>
    </div>
</div>
<div class="content">
</div>
<div class="footer">
</div>

＆＃13;

＆＃13;

＆＃13;