CSS float behaving mysteriously - html

Question

I'm using Bootstrap 3 to create a mobile responsive website.
There are two top level menus on my webpage. Top menu has a ul floated to right and the menu below that has two components: a ul floated left and a search box floated right.
Although float: right is working on the search box, it is not moving to extreme right as it should; instead it leaves some space from right. I haven't applied any right margin to the search box.
However, when I remove float from the top menu's ul (.settings-menu ul), the search box moves to extreme right. The two menus are in different divs. I can't understand why this is happening. Can someone explain why this happening and recommend a solution? My code is as follows:
<div class="settings-menu"> <!-- Top settings/registration panel -->
<ul>
<li><a>Register</a></li>
<li><a>LogIn</a></li>
<li><a>Wishlist(0)</a></li>
<li><a>My Account</a></li>
</ul>
</div>
<nav class="navbar">
<div class="navbar-header">
<button type="button" class="navbar-toggle" data-toggle="collapse" data-target="#menu-collapse">
<span class="sr-only">Toggle navigation</span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
</button>
</div>
<div class="collapse navbar-collapse" id="menu-collapse">
<ul class="nav navbar-nav">
<li>Home Page</li>
<li>Shop by category</li>
<li>Designers</li>
<li>Blog</li>
<li>Contact Us</li>
</ul>
<form class="navbar-form" role="search">
<label for="id_search"></label>
<input type="text" id="id_search" class="form-control" name="search_item" placeholder="Search Store">
<button type="submit" name="search_button" id="id_search_button" class="search-button"></button>
</form>
</div><!-- /.navbar-collapse -->
</nav>
CSS:
body {
font-family: arial;
font-size: 12px;
background: url("images/texture_2.jpg")
}
.settings-menu {
background-color: #E87772;
border-bottom: 4px solid #F1ADAA;
height: 36px;
}
.settings-menu ul {
float: right;
width: auto;
margin-right: 5%;
}
.settings-menu ul li{
display: inline-block;
padding: 5px;
list-style: none;
}
.settings-menu ul li a{
color: #fff;
font-size: 14px;
}
nav {
background-color: #fff;
width: 100%;
}
nav ul {
float: left;
}
.navbar-nav > li { /*over-riding bootstrap's classes */
display: inline-block;
padding: 7px;
margin-right: 7px;
}
.navbar-nav > li > a{
font-size: 16px;
color: rgb(80,80,80);
padding: 0px;
padding-bottom: 7px;
}
.navbar-nav > li > a:hover{
background-color: #fff;
}
.navbar-nav > li > a:after{
background: none repeat scroll 0 0 #e87772;
bottom: 0;
content: " ";
height: 2px;
left: 50%;
position: absolute;
transition: all 0.25s ease-in-out 0s;
width: 0;
}
.navbar-nav > li > a:hover:after, .navbar-nav > li > a:focus:after {
left: 0;
width: 100%;
}
.navbar-form {
float: right;
display: inline-block;
margin-top: 0;
width: 285px;
height: 45px;
}
.navbar-form .search-button {
background: url("images/icon-search-button.png") no-repeat;
border-radius: 100%;
background-color: #E87772;
height: 38px;
width: 38px;
background-position: center;
border: none;
transition-property: height, width;
transition-duration: 50ms;
transition-timing-function: ease-in-out;
}
.navbar-form .search-button:hover {
height: 40px;
width: 40px;
}
.navbar-form .cart-button {
background: url("images/icon-cart-link.png") no-repeat;
border-radius: 100%;
background-color: #E87772;
height: 38px;
width: 38px;
background-position: center;
border: none;
transition-property: height, width;
transition-duration: 50ms;
transition-timing-function: ease-in-out;
}
.navbar-form .cart-button:hover {
height: 40px;
width: 40px;
}
#id_search { /* for text-box */
border-radius: 0px;
border-right: none;
border-left: none;
border-top: 1px solid #DDDDDD;
border-bottom: 1px solid #DDDDDD;
box-shadow: none;
margin-top: 5px;
}
#search-box {
float: right;
}

Answer 1

.navbar-collapse.collapse have default padding by bootstrape. try this Demo
.navbar-collapse.collapse{
padding-right :0 !important;
}