下拉仅适用于怪异模式

Question

我有一个下拉菜单，只有当IE9及其处于怪癖模式时才会起作用。我没有宣布任何高度。如果声明宽度，则设置为100％或自动。

在标准模式下，会出现菜单，但只有顶部是可见的，因为它的父容器会被切断。

HTML

<div id="secondary-nav" class="nav" role="toolbar" aria-label="User Tools">
    <div class="wrapper">
        <ul class="group">
            <li><a href="">1</a></li>

            <li><a href="">2</a></li>

            <li><a href="">3</a></li>

            <li><a href="">4</a></li>

            <li><a href="">4</a></li>

            <li><a href="">5</a></li>
        </ul>
    </div><!-- /.wrapper -->
</div><!-- /#secondary-nav -->

<div id="page-top" class="group">
    <div class="wrapper">
        <div id="branding" class="hgroup group">
            <h1 class="logo"><a href="/">Logo</a></h1>
        </div>

        <div id="menu-button"></div>

        <div id="global-nav" class="nav" role="navigation" aria-label="Main Site Navigation">
            <ul>
                <li><a href="">1</a></li>

                <li><a href="">2</a></li>

                <li><a href="">3</a></li>

                <li><a href="">4</a></li>

                <li class="expand group">Log-in

                    <ul class="user-menu sub-nav group" role="menu" aria-label="User Menu">
                        <li class="user-login group">' . render(drupal_get_form('user_login_block')) . ' ' . fboauth_action_display('connect') . '</li>
                    </ul>
                </li>
            </ul>
        </div>
    </div>
</div>

CSS

/* Header 
-------------------------------------------------- */

#page-top {
    border-top:2px solid #32568F;
    color:#fff;
    width:100%;
    overflow:visible;
    z-index:9999;
    background: #000c2d;
    background: -moz-linear-gradient(top,  #000c2d 0%, #172842 10%, #172842 60%, #193154 100%);
    background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,#000c2d), color-stop(10%,#172842), color-stop(60%,#172842), color-stop(100%,#193154));
    background: -webkit-linear-gradient(top,  #000c2d 0%,#172842 10%,#172842 60%,#193154 100%);
    background: -o-linear-gradient(top,  #000c2d 0%,#172842 10%,#172842 60%,#193154 100%);
    background: -ms-linear-gradient(top,  #000c2d 0%,#172842 10%,#172842 60%,#193154 100%);
    background: linear-gradient(to bottom,  #000c2d 0%,#172842 10%,#172842 60%,#193154 100%);
    filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#000c2d', endColorstr='#193154',GradientType=0 );
}

#page-top .wrapper, #secondary-nav .wrapper { /* Added for old theme consistency, remove! */
    max-width: 960px;
}

#branding {
    display:block;
    padding-top:.9em;
    margin-left: .5em;
    line-height:2em;
    vertical-align:middle;
    float: left;
}

#branding h1.logo, .footer-logo {
    display:inline-block;
    margin:0;
    margin-right: .15em;
    padding:0;
    width:24px;
    height:27px;
    float:left;
    text-indent:100%;
    overflow:hidden;
    background:url(../images/logo@2x.png) no-repeat left top;
    vertical-align:bottom;
    background-size: auto 100%;
}

#branding h1.logo a{
    display:block;
}

#branding p {
    display:block;
    font-family:'MuseoSlab','Times New Roman',serif;
    font-size:1.2em;
    font-weight:500;
    float:left;
    margin-left:.25em;
    padding:0;
    color: #fff;
    margin: 0;
    padding: 0;
}

#branding p a {
    color: #fff;
}

#branding p a:hover {
    color: #a1c336;
    text-decoration: none;
}

a.skip {
    position:absolute;
    left:-999em;
}


/* Primary Navigation
-------------------------------------------------- */

/* NEW HEADER! */

#global-header * {
    box-sizing:border-box;
    -moz-box-sizing: border-box;
}

html {
    font-size:100%;
}

body {
    margin:0 auto;
    font:1em/1 Helvetica,Arial,sans-serif;
    width:100%;
}

#global-header {
    width:100%;
}

.wrapper {
    margin:0 auto;
    padding: 0 1em;
    max-width:960px;
}

.nav ul {
    list-style:none;
}

.nav ul > li {
    display:block;
    float:left;
}

.nav li a {
    display:block;
}

[role=toolbar] {
    display:block;
    margin:0 auto;
    width:100%;
    background:url(grey_diagnol.png) repeat;
    overflow:hidden;
}

[role=toolbar] ul {
    display:block;
    margin:0 auto;
    font-size:.75em;
    float:right;
}

[role=toolbar] li {
    margin:.5em 0;
}

[role=toolbar] li:not(:last-child) {
    border-right:1px solid #436394;
}

[role=toolbar] li a {
    color:#436394;
    text-decoration:none;
    padding:.25em .72em;
}

[role=toolbar] li.citypicker a {
    display: inline-block;
    padding-left: 0;
}

[role=toolbar] a.ddlocation {
    padding-right: .25em;
}


a.choose-location {
    font-size: .5em;
    color: #efefef;
    text-transform: uppercase;
}

[role=toolbar] a:hover {
    color:#a1c336;
}

#page-top {
    border-top:2px solid #32568F;
    background-color:#172842;
    color:#fff;
    width:100%;
    overflow:visible;
    z-index: 9999;
}

.fixed {
    position: fixed;
    top: 0;
    box-shadow: 0px 1px 8px #222;
}

#branding {
    display:inline;
    float:left;
    padding-top:.9em;
    line-height:2em;
    vertical-align:middle;
}

#branding h1.logo {
    display:inline-block;
    margin:0;
    padding:0;
    width:124px;
    height:27px;
    float:left;
    text-indent:100%;
    overflow:hidden;
    background:url(logo.png) no-repeat left top;
    vertical-align:bottom;
}

#branding p {
    display:block;
    font-family:'MuseoSlab500',Georgia,'Times New Roman',serif;
    font-size:1.2em;
    font-weight:500;
    float:left;
    margin-left:.25em;
    padding:0;
    color: #fff;
}

#branding p a {
    color: #fff;
}

#branding p a:hover {
    color: #a1c336;
    text-decoration: none;
}

[role=navigation] ul {
    display:block;
    margin:0;
    padding:0;
    float:right;
}

[role=navigation] li {
    display:block;
    position:relative;
    margin-bottom:-5px;
    font-family:'MuseoSlab500',Georgia,'Times New Roman',serif;
    font-weight:500;
    font-size:1.2em;
    text-transform:lowercase;
}

[role=navigation] li:hover {
    background:#b4df5b;
    background:-moz-linear-gradient(top,#a1c336 0%,#88a13d 100%);
    background:-webkit-gradient(linear,left top,left bottom,color-stop(0%,#a1c336),color-stop(100%,#88a13d));
    background:-webkit-linear-gradient(top,#a1c336 0%,#88a13d 100%);
    background:-o-linear-gradient(top,#a1c336 0%,#88a13d 100%);
    background:-ms-linear-gradient(top,#a1c336 0%,#88a13d 100%);
    background:linear-gradient(to bottom,#a1c336 0%,#88a13d 100%);
    filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#a1c336',endColorstr='#88a13d',GradientType=0);
    box-shadow:0 1px 4px #000;
    text-shadow:1px 1px 1px #3D4427;
    color:#fff;
}

.expand-hover-js {
    background:#b4df5b;
    background:-moz-linear-gradient(top,#a1c336 0%,#88a13d 100%);
    background:-webkit-gradient(linear,left top,left bottom,color-stop(0%,#a1c336),color-stop(100%,#88a13d));
    background:-webkit-linear-gradient(top,#a1c336 0%,#88a13d 100%);
    background:-o-linear-gradient(top,#a1c336 0%,#88a13d 100%);
    background:-ms-linear-gradient(top,#a1c336 0%,#88a13d 100%);
    background:linear-gradient(to bottom,#a1c336 0%,#88a13d 100%);
    filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#a1c336',endColorstr='#88a13d',GradientType=0);
    box-shadow:0 1px 4px #000;
    text-shadow:1px 1px 1px #3D4427;
    color:#fff;
}

[role=navigation] a {
    color:#fff;
    text-decoration:none;
    padding:1em;
}

[role=navigation] li.expand a {
    vertical-align: bottom;
}
[role=navigation] .user-name {
    display: inline-block;
    position: relative;
    max-width: 16em;
    overflow: hidden;
    font:.64em Helvetica,Arial,sans-serif;
    color:#a2bf39;
    text-transform:uppercase;
    text-overflow: ellipsis;
    text-shadow:none;
    vertical-align: baseline;
}

[role=navigation] li:hover .user-name {
    color:#172842;
}

.user-name-hover-js {
    color:#172842 !important;
}

.message-count {
    display: block;
    position: absolute;
    top: 0;
    right: 0;
    box-shadow: 0px 1px 4px #222;
    border: 1px solid #172940;
    border-radius: 50px;
    padding: .25em .5em;
    background-color: #d52424;
    font: .62em Helvetica, Arial, sans-serif;
    font-weight: bold;
    color: white;
    cursor: default;
}

/*
.message-count:hover {
    background-color: red;
    border: 2px solid white;
    box-shadow: 0px 1px 4px white;
}
*/

[role=navigation] li ul.sub-nav {
    display:none;
    position:absolute;
    top:2.7em;
    left:-4em;
    width: auto;
    z-index: 9999;
    box-shadow:0 1px 8px rgba(23,40,66,.5);
    border-right:1px solid #172842;
    border-bottom:1px solid #172842;
    border-left:1px solid #172842;
    background-color:#ededf4;
    overflow: hidden;
}


.sub-nav li {
    float:none;
    display:block;
    font-size:14px;
    font-size:.82rem;
    font-family:Helvetica,Arial,sans-serif;
    font-weight:400;
    width: 100%;
    margin:0;
    text-shadow:none;
    position: relative;
}

.sub-nav li:hover {
    background:#a1c336;
    text-shadow:none;
    box-shadow:none;
}

.sub-nav li a {
    display: block;
    padding:.75em 1em;
    color:#172842;
    text-transform: none;
}

.sub-nav li a:hover {
    color:#fff;
}

.sub-nav li a.has-notify {
    display: block;
    padding-right: 0;
    float: left;
}

.sub-nav li .menu-notify {
    display: block;
    float: right;
    padding:1.5em .5em 0 .5em;
    font-size: .72em;
    color:#436394;
    width: auto;
}

.sub-nav li:hover .menu-notify {
    color: #fff;
}

.sub-nav .menu-notify a {
    display: inline;
    padding: 0;
    color:#436394;
}

.sub-nav .menu-notify a:hover {
    color:#436394;
    text-decoration: underline;
}

/* Login Forms */

.sub-nav li.user-login {
    padding: 1em;
    display: block;
}

.sub-nav li.user-login:hover,
[role=navigation] li ul.sub-nav li.user-login:hover{
    background-color: #ededf4 !important;
    background:#ededf4;
    filter: progid:DXImageTransform.Microsoft.gradient(enabled = false);
    filter: none;
    box-shadow: 0;
    text-shadow: 0;
}


.not-front #user-login-form, #user-login {
    margin-top: 1em;
}

#user-login {
    margin: 1em;
    display: block;
    overflow: hidden;
    padding: .5em;
}

.not-front #user-login-form input, #user-login input {
    padding: .5em;
    font-size: 1em;
    margin-bottom: .5em;
    display: block;
    width: 100%;
    box-sizing: border-box;
    -moz-box-sizing: border-box;
}

#user-login-form div, #user-login div {
    display: block;
}
.not-front #user-login-form label, #user-login label {
    color: #222;
    text-transform: none;
    display: block;
}
#user-login label {
    margin-top: 1em;
}
#user-login .description {
    font-size: .75em;
}

.not-front #user-login-form .item-list, #user-login .item-list {
    margin: .5em 0;
    display: block;
    overflow: hidden;
}
.not-front #user-login-form .item-list li, #user-login .item-list li {
    padding:0;
    font-size: .75em
}

.not-front #user-login-form .item-list a, #user-login .item-list a {
    padding: .5em 0 0 0;
}

.not-front #user-login-form .item-list a:hover, #user-login .item-list a:hover {
    background-color: #EDEDF4;
    color: #A2BF39;
}

.not-front #user-login-form input[type=submit], #user-login input[type=submit] {
    background:#a1c336;
    background:-moz-linear-gradient(top,#a1c336 0%,#88a13d 100%);
    background:-webkit-gradient(linear,left top,left bottom,color-stop(0%,#a1c336),color-stop(100%,#88a13d));
    background:-webkit-linear-gradient(top,#a1c336 0%,#88a13d 100%);
    background:-o-linear-gradient(top,#a1c336 0%,#88a13d 100%);
    background:-ms-linear-gradient(top,#a1c336 0%,#88a13d 100%);
    background:linear-gradient(to bottom,#a1c336 0%,#88a13d 100%);
    filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#a1c336',endColorstr='#88a13d',GradientType=0);
    font:14px MuseoSlab500,Georgia,Times New Roman,serif;
    text-shadow:1px 1px 2px #737863;
    color:#fff;
    padding:.5em 2em;
    box-shadow:1px 1px 3px 0 #737863;
    border:none;
    cursor:pointer;
    display: block;
    margin: .5em 0;
}

#user-login input {
    width: auto;
}

.not-front #user-login-form input[type=submit]:hover, #user-login input[type=submit]:hover {
    background: #b9d955;
    background: -moz-linear-gradient(top,  #b9d955 0%, #a0b858 100%);
    background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,#b9d955), color-stop(100%,#a0b858));
    background: -webkit-linear-gradient(top,  #b9d955 0%,#a0b858 100%);
    background: -o-linear-gradient(top,  #b9d955 0%,#a0b858 100%);
    background: -ms-linear-gradient(top,  #b9d955 0%,#a0b858 100%);
    background: linear-gradient(to bottom,  #b9d955 0%,#a0b858 100%);
    filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#b9d955', endColorstr='#a0b858',GradientType=0 );
    text-shadow:1px 1px 2px #ccc;
    text-decoration: none;
}

.not-front a.facebook-action-connect {
    background: none !important;
    height: 21px;
    padding: 0 !important;
    width: 89px;
    display: block;
    float: none !important;
    margin-top: 1em !important;
}

Answer 1

看起来问题是使用overflow：hidden会隐藏这些标签中包含的所有内容，包括你的下拉。