My navigation bar is vertical but won't go horizontal - html

Question

I've been having trouble making my navigation bar for some reason. I've tried looking at if anything here answers it or going online but have had no luck. Am I missing something or is there a conflict?
html, body {
margin: 0;
padding: 0;
}
.container {
max-width: 940px;
margin: 0 auto;
padding: 0 10px;
}
.jumbotron {
background: url(../img/bg.jpg) no-repeat center center;
background-size: cover;
height: 800px;
}
.header {
background-color: #333;
}
.nav {
list-style-type: none;
margin: 0;
padding: 20px 0;
}
.nav li a {
color: #fff;
display: inline;
font-family: 'Raleway', sans-serif;
font-weight: 600;
font-size: 12px;
margin-right: 25px;
text-transform: uppercase;
}
<div class="header">
<div class="container">
<ul class="nav" role="navigation">
<li>About</li>
<li>Photography</li>
<li>Programming</li>
<li>Writing</li>
<li>Reading</li>
<li>Contact</li>
</ul>
</div>
</div>

Answer 1

I made you a plunker as an example. You were very close. You just need to set the display property on the .nav li selector to inline-block.
.nav li {
display:inline-block;
}
The poster was actually looking for a Bootstrap solution but didn't have the question tagged as such. Here is a Bootstrap example. It just uses the pull-left class on each li tag.
<ul class="nav" role="navigation">
<li class="pull-left">About</li>
<li class="pull-left">Photography</li>
<li class="pull-left">Programming</li>
<li class="pull-left">Writing</li>
<li class="pull-left">Reading</li>
<li class="pull-left">Contact</li>
</ul>

Answer 2

In your CSS, try adding
.nav li {
display: inline;
}
Your li elements are naturally block displayed, so this should go ahead and remove the breaks from in between them.

Answer 3

See the fixed code snippet bellow. You need to add display: inline; to the li elements to make them go horizontal.
li {
display: inline;
}
html, body {
margin: 0;
padding: 0;
}
.container {
max-width: 940px;
margin: 0 auto;
padding: 0 10px;
}
.jumbotron {
background: url(../img/bg.jpg) no-repeat center center;
background-size: cover;
height: 800px;
}
.header {
background-color: #333;
}
.nav {
list-style-type: none;
margin: 0;
padding: 20px 0;
}
.nav li a {
color: #fff;
display: inline;
font-family: 'Raleway', sans-serif;
font-weight: 600;
font-size: 12px;
margin-right: 25px;
text-transform: uppercase;
}
<div class="header">
<div class="container">
<ul class="nav" role="navigation">
<li>About</li>
<li>Photography</li>
<li>Programming</li>
<li>Writing</li>
<li>Reading</li>
<li>Contact</li>
</ul>
</div>
</div>

Answer 4

Add the attribute .nav li with inline display.
.nav li{
display: inline;
}