How do i get a css sheet to link to an html document

Durango Jewelry Pendant Gem #main { border-radius: 2em; }
<div id="outerwrapper">

<header>

	<img class="addrightmargin"	src="wirewrap01.jpg" alt="smoky quartz pendant" width="171" height="171">

	<h1>Durango Jewelry and Gem Shop</h1>

	<h2>Distinguished wire wrapped jewelry, pendants, and gems</h2>  

</header>

<nav>

	<ul>

		<li><a href="classics.html">Classics</a>&nbsp;</li>

		<li><a href="specials.html">Specials</a>&nbsp;</li>

		<li><a href="gems.html">Gems</a>&nbsp;</li>

		<li><a href="contact.html">Contact Me</a>&nbsp;</li>

	</ul>

</nav>

<div id="main">

	<p>Durango Jewelry and Gem Shop pampers you with one-of-a-kind, high-quality wire wrapped pendants and gems.  

	Our works of art are inspired by natural geometries and the vast beauty of mother nature.</p> 

	<p>The featured pendant provides these characteristics:</p>

		<ul> 

			<li> gemstone is <Span style="font-weight:bold;">"Smoky quartz"</span> 

			also called a <Span style="font-weight:bold;">Soulmate Crystal"</span></li>

			<li>gemstone is over two carats</li>	

			<li>wire is a mixture of antique color copper and .930 pure silver</li>

			<li>high-quality silver allow requires very little polishing</li>

			<li>pendant is approximately 4cm x 3cm</li>

		</ul>

	<p>Come to Durango Jewelry and Gem Shop to make your stay in Durango a life-time treasure.</p>

</div><!--end main-->

<footer>

	<p>Durango Jewelry and Gem Shop, 10101 Main Street, Durango, CO | Established 1979</p>

	<a href="mailto:[email protected]">Contact us through email</a>

</footer>

is my html code and here is my css code

/style.css/
/William Decker
05/18/17
/
body { color: #000000;
background-color: #D9F1C1;
}

#outerwrapper { width: 80%;
margin; 0 auto 0 auto;}

header, nav, footer { font-family: Calibri, Arial, sans-serif;
}
#main { font-family: Garamond, “Times New Roman”, serif;
}

footer { font-size: 0.75em;
text-alin: center;
}

background-color: #F0F9E6;
padding: 10px;
img { float: left;
}

nav { clear: both;
}
.addrightmargin {margin-right: 2%;
}

sowhy is it not working

So in your html you need to link you’re css, like this.

<link href="style.css" type="text/css" rel="stylesheet">

But the name of the href="style.css" depends on the file name.