コーポレートサイトなど情報量が多いサイトでは、リンク先のページに飛んでからさらにそのページの中から目当てのコンテンツを探さなければならない、といった手間がかかります。
メガドロップダウンメニューであれば、リンク先のページの中の目当てのコンテンツにダイレクトに飛べるので、ユーザーの手間が省けるわけです。ユーザビリティの向上のためにも情報量の多いサイトであれば積極的に使っていきましょう。
メガドロップダウンメニューを採用しているサイト例
www.tiffany.co.jp
www.nike.com
www.nodai.ac.jp
<html lang="ja">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>drop-menu</title>
<link rel="stylesheet" href="css/style.css">
</head>
<body>
<h1>drop-menu</h1>
<nav class="g-nav">
<ul>
<li><a href="#">トップ</a></li>
<li class="drop">メニュー
<ul class="menu-child">
<li><a href="menu/index.html#lunch">ランチ</a></li>
<li><a href="menu/index.html#dinner">ディナー</a></li>
<li><a href="menu/index.html#course">コース</a></li>
</ul>
</li>
<li><a href="#">アクセス</a></li>
</ul>
</nav>
</body>
</html>
@charset "utf-8";
html{box-sizing:border-box;text-size-adjust:100%}*,:after,:before{background-repeat:no-repeat;box-sizing:inherit}:after,:before{text-decoration:inherit;vertical-align:inherit}*{padding:0;margin:0;box-sizing:border-box;}audio:not([controls]){display:none;height:0}hr{overflow:visible}article,aside,details,figcaption,figure,footer,header,main,menu,nav,section,summary{display:block}summary{display:list-item}small{font-size:80%}[hidden],template{display:none}abbr[title]{border-bottom:1px dotted;text-decoration:none}a{background-color:transparent;text-decoration-skip:objects}a:active,a:hover{outline-width:0}code,kbd,pre,samp{font-family:monospace,monospace}b,strong{font-weight:bolder}dfn{font-style:italic}mark{background-color:#ff0;color:#000}sub,sup{font-size:75%;line-height:0;position:relative;vertical-align:baseline}sub{bottom:-.25em}sup{top:-.5em}input{border-radius:0}[role=button],[type=button],[type=reset],[type=submit],button{cursor:pointer}[disabled]{cursor:default}[type=number]{width:auto}[type=search]{appearance:textfield}[type=search]::search-cancel-button,[type=search]::search-decoration{appearance:none}textarea{overflow:auto;resize:vertical}button,input,optgroup,select,textarea{font:inherit}optgroup{font-weight:700}button{overflow:visible}[type=button]::focus-inner,[type=reset]::focus-inner,[type=submit]::focus-inner,button::focus-inner{border-style:0;padding:0}[type=button]::focus-inner,[type=reset]::focus-inner,[type=submit]::focus-inner,button:focusring{outline:1px dotted ButtonText}[type=reset],[type=submit],button,html [type=button]{appearance:button}button,select{text-transform:none}button,input,select,textarea{background-color:transparent;border-style:none;color:inherit}select{appearance:none;appearance:none}select::expand{display:none}select::value{color:currentColor}legend{border:0;color:inherit;display:table;max-width:100%;white-space:normal}::file-upload-button{appearance:button;font:inherit}[type=search]{appearance:textfield;outline-offset:-2px}img{border-style:none;vertical-align: bottom}progress{vertical-align:baseline}svg:not(:root){overflow:hidden}audio,canvas,progress,video{display:inline-block}@media screen{[hidden~=screen]{display:inherit}[hidden~=screen]:not(:active):not(:focus):not(:target){position:absolute!important;clip:rect(0 0 0 0)!important}}[aria-busy=true]{cursor:progress}[aria-controls]{cursor:pointer}[aria-disabled]{cursor:default}::selection{background-color:#b3d4fc;color:#000;text-shadow:none}::selection{background-color:#b3d4fc;color:#000;text-shadow:none}ul,ol{list-style:none;}a{text-decoration:none;}.wrapper{overflow:hidden;}body{overflow-y:scroll;}img{max-width: 100%;}
h1{
text-align: center;
padding: 40px 0;
}
.g-nav{
width: 100%;
height: 50px;
background-color: darkgray;
margin: 50px auto 500px;
position: relative;
}
.g-nav>ul{
display: flex;
width: 600px;
margin: 0 auto;
}
.g-nav>ul>li{
width: 33.33%;
height: 50px;
background-color: crimson;
color: #FFF;
text-align: center;
line-height: 50px;
}
.g-nav>ul>li:nth-of-type(-n+2){
border-right: 1px solid #FFF;
}
.g-nav>ul>li:nth-of-type(2){
cursor: pointer;
}
.g-nav>ul>li>a{
display: block;
text-align: center;
line-height: 50px;
color: #FFF;
}
.g-nav>ul>li>a:hover{
background-color: #8f3544;
}
.menu-child{
width: 100%;
height: 150px;
opacity: 0;
visibility: hidden;
position: absolute;
top: 50px;
left: 0;
}
.drop:hover>.menu-child{
opacity: 1;
visibility: visible;
transition: 1s;
}
.menu-child>li{
height: 50px;
}
.menu-child a{
display: block;
text-align: center;
line-height: 50px;
background-color: #9b0f49;
color: #FFF;
border-top: 1px solid #FFF;
}
.menu-child a:hover{
background-color: #e71515;
}
