CSS：菜单栏和内容样式问题

Question

我目前正在向网页添加导航栏。但我遇到了一些CSS样式问题。导航菜单栏正在推动下面的内容，在两者之间留下巨大的差距并使其不均匀。我采取了预防措施，遗漏了任何会像margin bottom-padding那样陷入困境的事情，但我仍然得到了相同的结果。如何让菜单栏不影响下面的内容？ EXAMPLE

添加了导航栏：

如果没有导航栏，则下面的内容为：

我已将导致问题的特定css规则添加到devgrow.css：

<style>
#navigation {
    position:relative;
    top:-45px;
    left:450px;
}

#au_title {
    color: #FC821D;
    font-size: 120%;
    font-weight: bold;
    left: 515px;
    letter-spacing: 2px;
    position: relative;
    text-transform: uppercase;
    top: -105px;
}

#searchInput {
    left: 700px;
    position: relative;
    top: -180px;
}

#contentNav { color: #cfdae3; }


/* Dark Button CSS */
.buttonNav {
    outline: 0;
    padding: 5px 12px;
    display: block;
    color: #EBEBEB;
    font-weight: bold;
    text-shadow: 1px 1px #1f272b;
    border: 1px solid #1c252b;
    border-radius: 3px;
    -moz-border-radius: 3px;
    -webkit-border-radius: 3px;
    background: #232B30; /* old browsers */
    background: -moz-linear-gradient(top, #3D4850 3%, #313d45 4%, #232B30 100%); /* firefox */
    background: -webkit-gradient(linear, left top, left bottom, color-stop(3%,#3D4850), color-stop(4%,#313d45), color-stop(100%,#232B30)); /* webkit */
    filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#3D4850', endColorstr='#232B30',GradientType=0 ); /* ie */
    box-shadow: 1px 1px 1px rgba(0,0,0,0.2); /* CSS3 */
    -moz-box-shadow: 1px 1px 1px rgba(0,0,0,0.2); /* Firefox */
    -webkit-box-shadow: 1px 1px 1px rgba(0,0,0,0.2); /* Safari, Chrome */
}
.buttonNav:hover {
    color: #fff;
    background: #4C5A64; /* old browsers */
    background: -moz-linear-gradient(top, #4C5A64 3%, #404F5A 4%, #2E3940 100%); /* firefox */
    background: -webkit-gradient(linear, left top, left bottom, color-stop(3%,#4C5A64), color-stop(4%,#404F5A), color-stop(100%,#2E3940)); /* webkit */
    filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#4C5A64', endColorstr='#2E3940',GradientType=0 ); /* ie */
}
.buttonNav:active {
    background-position: 0 top;
    position: relative;
    top: 1px;
    color: #fff;
    padding: 6px 12px 4px;
    background: #20282D; /* old browsers */
    background: -moz-linear-gradient(top, #20282D 3%, #252E34 51%, #222A30 100%); /* firefox */
    background: -webkit-gradient(linear, left top, left bottom, color-stop(3%,#20282D), color-stop(51%,#252E34), color-stop(100%,#222A30)); /* webkit */
    filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#20282D', endColorstr='#222A30',GradientType=0 ); /* ie */
    -moz-box-shadow: 1px 1px 1px rgba(255,255,255,0.1); /* Firefox */
    -webkit-box-shadow: 1px 1px 1px rgba(255,255,255,0.1); /* Safari, Chrome */
    box-shadow: 1px 1px 1px rgba(255,255,255,0.1); /* CSS3 */
}

/* Other stuff: */
.button-list { list-style: none; width: 100%; float: left; display: block; }
.button-list li { float: left; margin: 0 5px 0 0; }
.button-list li.search { padding-left: 18px; margin-left: 10px; position: relative; }

/* Search CSS: */
.search-input {
    padding: 0 5px 0 22px;
    border: 2px solid #DADADA;
    height: 30px;
    font-size: 12px;
    line-height: 30px;
    border-radius: 25px;
    -moz-border-radius: 25px;
    -webkit-border-radius: 25px;
    background: #FFF; /* old browsers */

}
.search-input:focus {outline: none;}

.search-submit {
    width: 13px;
    height: 13px;
    border: none;
    background: url(images/mag-glass.png) no-repeat;
    display: block;
    position: absolute;
    left: 26px;
    top: 10px;
    text-indent: -9999em;
}
</style>

Answer 1

首先我要说编码非常糟糕。要解决该问题，请从您button-list移除浮动。写得像这样：

.button-list {
    list-style: none outside none;
    overflow: hidden;
}

Answer 2

嗨现在定义 overflow hidden在您的css中#contentArea ID

就像这样

#contentArea {
    overflow: hidden;

}

Answer 3

在第一个内容区域的CSS中添加样式清除

<div id="contentArea" style="clear:both">