html - 为什么三行菜单导航图标不显示？

Question

请看下面的代码，如果有错误请告诉我。即使我从#menu-icon 中删除“隐藏”，它也不会显示导航图标的图像。抱歉发布了全部内容，但我只是想确保我没有写一些我不应该写的东西。

@import 'https://fonts.googleapis.com/css?family=Alegreya+Sans';

*{
    margin: 0;
    padding: 0;
    border: 0;
}
body {
    background-color: #F5F5F5;
    color: #67727A;
    font-family: 'Alegreya', sans-serif;
    margin: 0;
}
h2 {
    font-size: 250%;
    font-weight: 700;
    text-align: center;
    padding-top: 2%;
    color: #F5F5F5;
}
h3 {
    font-size: 175%;
    line-height: 155%;
    padding: 5% 0;
    font-weight: 400;
    color: #F5F5F5;
}
p {
    font-family: 'Alegreya sans', sans-serif;
    color: #F5F5F5;
    font-size: 160%;
    line-height: 150%;
    padding: 3%;
    text-indent: 2%;
    text-align: justify;
}
img {
    max-width: 100%;
    height: auto;
    width: auto;
    margin: -4px;
}
header {
    background-color: #6991AC;
    width: 100%;
    height: 86px;
}
#header-inner {
    max-width: 1200px;
    margin: 0 auto;
}
#logo {
    margin: 20px;
    float: left;
    width: 200px;
    height: 60px;
    background: url(img/RD.png) no-repeat center;
}
/*-- Start Navigation --*/
nav {
    float: right;
    padding: 25px 20px 0 0;
}
#menu-icon {
    display: hidden;
    width: 40px;
    weight: 40px;
    background: url(img/nav.png) center;
}
a:hover#menu-icon {
    border-radius: 4px 4px 0 0;
}
ul {
    list-style-type: none;
}
nav ul li {
    font-family: 'Alegreya Sans', sans-serif;
    font-size: 150%;
    display: inline-block;
    float: left;
    padding: 10px;
}
nav ul li a {
    color: #f5f5f5;
    text-decoration: none;
}
nav ul li a:hover {
    color: #C3D7DF;
}
.current {
    color:#C3D7DF;
}
/*-- End Navigation --*/
.banner {
    width: 100%;
    background-color: #6991AC;
}
.banner-inner {
    max-width: 1100px;
    margin: 0 auto;
}
.one-fourth {
    width: 25%;
    float: left;
    text-align: center;
}
#html {
    background-color: #F1AA90;
}
#css{
    background-color: #BEB9AD;
}
#seo {
    background-color: #AADCD2;
}
#social {
    background-color: #A2B2C1;
}
.one-fourth i {
    color: #F0F0F0;
    font-size: 500%;
    padding: 13% 0 4% 0;
}
.inner-wrapper {
    float: left;
    width: 100%;
    background-color: #C3D7DF;
}
article {
    float: left;
    margin: 0 auto;
    width: 50%;
    height: auto;
}
#tablet {
    background-color: #C3D7DF;
}
aside {
    float: right;
    margin: 0 auto;
    width: 50%;
    height: auto;
}
#tablet2 {
    background-color: #A2B1C1;
}
#mobile {
    background-color: #BEB9AD;
}
#desktop {
    background-color: #F1AA90;
}
.inner-wrapper-2 {
    float: left;
    width: 100%;
    background-color: #C3D7DF;
}
.inner-wrapper-3 {
    float: left;
    width: 100%;
    background-color: #AADCD2;
}
.one-third {
    width: 33.333333%;
    float: left;
    text-align: center;
}
#google {
    background-color: #A2B1C1;
}
#marketing {
    background-color: #BEB9AD;
}
#customers {
    background-color: #AADCD2;
}
#smiley {
    background-color: #AADCD2;
    padding: 0 0 1%;
    clear: both;
}
/*-- Start Footer ---*/
footer {
    background-color: #6991AC;
    width: 100%;
}
.social {
    list-style-type: none;
    text-align: center;
}
.social li {
    display: inline;
}
.social i {
    font-size: 460%;
    margin: 1%;
    padding: 5% 5% 5% 4%;
    color: #C3D7DF;
}
.social i:hover {
    color: #F5F5F5;
}
footer.second {
    border-top: 1px solid #AADCD2;
    background-color: #544B59;
    max-height: 55px;
    text-align: center;
    margin: 0;
}
footer.second p {
    padding: 5px 0 9px 0;
    text-align: center;
}
/*====== MEDIA ========*/
@media screen and (max-width: 760px) {
    h2 {
        font-size: 150%;
    }
    h3 {
        font-size: 125%;
    }
    p {
        font-size: 120%;
    }
    header {
        position: absolute;
    }
    #logo {
        margine: 15px 0 20px -25px;
        background: url(img/RD_mobile.png) no-repeat center;
    }
    #menu-icon {
        display: inline-block;
    }
    nav ul, nav:active ul {
        display: none;
        z-index: 1000;
        position: absolute;
        padding: 20px;
        background: #6991AC;
        right: 20px;
        top: 60px;
        border: 1px solid #FFF;
        border-radius: 2px 0 2px 2px;
        width: 50%;
    }
    nav:hover ul {
        display: block;
    }
    nav li {
        text-align: center;
        width: 100%;
        padding: 10px 0;
    }
    .banner {
        padding-top: 86px;
    }
    .one-fourth {
        float: left;
        width: 100%;
    }
    .one-fourth i {
        font-size: 350%;
        padding: 4% 0 1% 0;
    }
    article {
        width: 100%;
    }
    aside {
        width: 100%;
    }
    .hand-mobile {
        display: none;
    }
    .one-third {
        width: 100%;
    }
    .social i {
        font-size: 180%;
    }
}

    <!DOCTYPE html> 
<html>
<head>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>Rocket Design - Mobile Web Design Services</title>
    <link rel="stylesheet" type="text/css" href="style.css" />  
    <link href="css/font-awesome.min.css" rel="stylesheet"/>
    <link rel="shortcut icon" type="image/png" href="img/favicon.png"/>
</head>
<body>
<header>
    <div id="header-inner">
        <a href="index.html" id="logo"></a>
        <nav>
            <a href="#" id="menu-icon"></a>
            <ul>
                <li><a href="index.html" class="current">Home</a></li>
                <li><a href="#">Skills</a></li>
                <li><a href="#">Portofolio</a></li>
                <li><a href="#">Our Team</a></li>
                <li><a href="#">Contact</a></li>
            </ul>
        </nav>
    </div>
</header>
<!--End Header-->
<section class="banner">
    <div class="banner-inner">
        <img src="img/rocket_design.png">
    </div>
</section>
<!--End Banner-->
<section class="one-fourth" id="html">
    <td><i class="fa fa-html5"></i></td>
    <h3>HTML</h3>
</section>
<section class="one-fourth" id="css">
    <td><i class="fa fa-css3"></i></td>
    <h3>CSS</h3>
</section>
<section class="one-fourth" id="seo">
    <td><i class="fa fa-search"></i></td>
    <h3>SEO</h3>
</section>
<section class="one-fourth" id="social">
    <td><i class="fa fa-users"></i></td>
    <h3>SOCIAL</h3>
</section>
<!--End Four Column Section-->
<section class="inner-wrapper">
    <article id="tablet">
        <img src="img/hand_ipad.png">
    </article>
    <aside id="tablet2">
        <h2>MOBILE. TABLET. DESKTOP.</h2>
        <p>A tablet computer, commonly shortened to tablet, is a thin, flat mobile computer with a touchscreen display, which is usually in color, processing circuitry, and a rechargeable battery in a single device. Tablets often come equipped with sensors, including digital cameras, a microphone, and an accelerometer, so that images on screens are always displayed upright.</p>
    </aside>
</section>
<section class="inner-wrapper-2">
    <article id="mobile">
        <h2>ACROSS EACH DEVICE</h2>
        <p>A tablet computer, commonly shortened to tablet, is a thin, flat mobile computer with a touchscreen display, which is usually in color, processing circuitry, and a rechargeable battery in a single device. Tablets often come equipped with sensors, including digital cameras, a microphone, and an accelerometer, so that images on screens are always displayed upright.</p>
    </article>
    <aside class="hand-mobile">
        <img src="img/hand_mobile.png">
    </aside>
</section>
<section class="inner-wrapper">
    <article>
        <img src="img/desktop.png">
    </article>
    <aside id="desktop">
        <p>A tablet computer, commonly shortened to tablet, is a thin, flat mobile computer with a touchscreen display, which is usually in color, processing circuitry, and a rechargeable battery in a single device. Tablets often come equipped with sensors, including digital cameras, a microphone, and an accelerometer, so that images on screens are always displayed upright.</p>
    </aside>
</section>
<!--End Main Two Column Section-->
<section class="inner-wrapper-3">
    <section class="one-third" id="google">
        <h3>GOOGLE SEARCH</h3>
        <p>A tablet computer, commonly shortened to tablet, is a thin, flat mobile computer with a touchscreen display, which is usually in color, processing circuitry, and a rechargeable battery in a single device.</p>
    </section>
    <section class="one-third" id="marketing">
        <h3>MARKETING</h3>
        <p>A tablet computer, commonly shortened to tablet, is a thin, flat mobile computer with a touchscreen display, which is usually in color, processing circuitry, and a rechargeable battery in a single device.</p>
    </section>
    <section class="one-third" id="customers">
        <h3>HAPPY CUSTOMOERS</h3>
        <p>A tablet computer, commonly shortened to tablet, is a thin, flat mobile computer with a touchscreen display, which is usually in color, processing circuitry, and a rechargeable battery in a single device.</p>
    </section>
</section>
<!--End Three Column Section-->
<section id="smiley">
    <h2>: )</h2>
</section>
<!--End Smiley Face-->
<footer>
    <ul class="social">
        <li><a href="#" target="_blank"><i class="fa fa-facebook"></i></a></li>
        <li><a href="#" target="_blank"><i class="fa fa-google-plus"></i></a></li>
        <li><a href="#" target="_blank"><i class="fa fa-twitter"></i></a></li>
        <li><a href="#" target="_blank"><i class="fa fa-youtube"></i></a></li>
        <li><a href="#" target="_blank"><i class="fa fa-instagram"></i></a></li>
    </ul>
</footer>
<!--End Footer-->
<footer class="second">
    <p>&copy; Rocket Design</p>
</footer>
<!--End Second Footer-->
</body>
</html>

Answer 1

您的 CSS 中的一个简单错误。而不是 weight: 40px; 它必须是 height: 40px

#menu-icon {
    display: hidden;
    width: 40px;
    height: 40px;
    background: url(img/nav.png) center;
}