background-color が変わらない。

ul list のbackground-color が変わりません。どうしてなのでしょうか？

html
1<!-- Assignment 18 % COMP112 Tomofumi Kimura index page-->
2<!DOCTYPE html>
3<html lang="en">
4	<head>
5	<!-- kimto341 child care-->
6		<meta charset = "UTF-8">
7		<link rel="stylesheet" type = "text/css" href="style.css">
8		<title>Child Care HomePage</title>
9	</head>
10	<body>
11	<!-- Main Heading-->
12	<div id = "header">
13	<h1>Welcome to Mama Bear Child Care</h1>
14	</div>
15	<!-- Navigation Area -->
16	<div id = "nav">
17	<ul>
18		<li><a class="active" href="index.html">Home</a></li>
19		<li><a href = "philosophy.html">Our Philosophy</a></li>
20		<li class = "dropdown"><a href="javascript:void(0)" class = "dropbtn">Our Centre</a>
21		<div class = "dropdown-content">
22		<a href="accelerated_programme.html">Mama Bear Accelerated Programme</a>
23		<a href="environment.html">Our Environment</a>
24		<a href="goals.html">Our Goals</a>
25		</div>
26		</li>
27
28
29		<li><a href="childs_day.html">The Childs Day</a></li>
30		<li><a href="settling.html">Settling in</a></li>
31		<li><a href = "staff.html">Our Staff</a></li>
32		
33	</ul>
34	</div>
35
36	<!-- Contact Area -->
37	<div id = "contacts">
38		<h3 id="contact_us">Contact Us</h3>
39		<h4>If you have any questions about the Mama Bear please contact us at:</h4>
40			<ul>
41				<li>enquiries@mamaBear.co.nz</li>
42				<li>123 Salmon Lake Lane</li>
43				<li>Big Bear City</li>
44			</ul>
45	</div>
46	<!-- Main Area -->
47	<div class="content">
48		<h2>Our Philosophy</h2>
49
50		<ul id = "philo_list">
51			<li>We believe in positive respectful partnerships between <br>children, families, caregivers and teachers where we value our community's diversity.</li>
52			<li>We aim to support children's learning through a stimulating prepared environment that nurtures and develops dispositions for learning and provides opportunities for success, challenges, individual interests, and freedom of choice.</li>
53
54			<li>Our community fosters contextual, collaborative and reciprocal learning, where teachers are facilitators, carers and friends of the children.</li>
55			<li>We empower children to be independent, competent, confident, compassionate and responsible human beings, and most importantly to have fun in the process.</li>
56			
57		</ul>
58
59	</div>
60	<!-- Footer area -->
61	<div id = "footer">
62		<footer>This website was created for a University project.  The content is largely fictional and no services are actually being offered.</footer>
63		
64	</div>
65		
66	</body>
67</html>

css
1/* COMP112 Assignment 18% tkimura Tomofumi Kimura stylesheet*/ 
2
3body{
4	background-color:rgb(224, 200, 202);
5	margin:0px;
6
7}
8
9/* main heading*/
10#header h1{
11	background-color:red;
12	text-align: center;
13	width:100%;
14	margin:0px;
15	padding:20px;
16	position:fixed;
17	top:0;
18	left:0;
19	right:0;
20}
21/* Navigation whole area */
22#nav{
23	background-color:rgb(87, 209, 204);
24	position:fixed;
25	top:75px;
26	left:0;
27	right:0;
28	width:100%;
29	margin:0px;
30}
31/* Navigation whole ul ara */
32#nav ul{
33	max-width:100%;
34	list-style-type:none;
35	padding:0;
36	margin-top:0px;
37	margin-left:150px;
38	margin-right:auto;
39	margin-bottom:auto;
40	overflow:hidden;
41	background-color:inherit;
42}
43/* Navigation list area*/
44#nav li{
45	float:left;
46	
47
48}
49
50/* Navigation list link, DropDown menu*/
51#nav li a, .dropbtn{
52	display:block;
53	color:inherit;
54	text-align:center;
55	padding:14px 30px 10px 30px;
56	text-decoration: none;
57
58
59}
60/* when user move the pointer to the place */
61#nav li a:hover, .dropdown:hover .dropbtn{
62	background-color:yellow;
63}
64
65#nav li.dropdown{
66	display:block;
67}
68/* drop down area*/
69.dropdown-content{
70	display:none;
71	position:absolute;
72	background-color:#f9f9f9;
73	min-width:100px;
74	box-shadow:0px 8px 16px 0px rgba(0,0,0,0.2);
75	z-index: 1;
76}
77/* drop down list element*/
78.dropdown-content a{
79	color:black;
80	padding:12px 16px;
81	text-decoration: none;
82	display:block;
83	text-align:left;
84}
85/* when mouse is over the drop down list element */
86.dropdown-content a:hover{
87	background-color:#f1f1f1;
88}
89
90.dropdown:hover .dropdown-content{
91	display:inline;
92}
93
94/* Contact Us Area*/
95
96#contacts{
97	position:fixed;
98	right:10px;
99	float:right;
100	width:220px;
101	margin-left:20px;
102	border-radius:25px;
103	border:2px solid #73AD21;
104	background-color:yellow;
105	padding:10px;
106}
107#contact_us{
108	color:red;
109}
110
111/* Main Area*/
112.content{
113	margin-top:170px;
114	margin-right:20px;
115	width:1100px;
116	height:auto;
117
118}
119
120
121/* h2 Mama Bear CHild Care heading */
122.content h2{
123	text-align: center;
124	color:rgb(0, 102,255);
125}
126.content h3{
127	text-align: center;
128
129}
130.content h4{
131	text-align:center;
132
133}
134.content span{
135	color:red;
136}
137#attention{
138	text-align:center;
139	background-color:rgb(153,204,255);
140	border:dotted 2px ;
141	padding-left:-10px;
142	border-radius: 40px;
143}
144
145/* Education Services UList*/
146.content ul{
147	margin:auto;
148	border-radius: 50px;
149	border:2px solid #73AD21;
150	padding:40px;
151	padding-top:10px;
152	width:400px;
153	height:140px;
154	background-color:rgb(153,204,255);
155	list-style-image: url('../Images/list_image/icn_12.gif');
156}
157.content li{
158	padding:20px;
159}
160/* Philosophy page List */
161#philo_list{
162	border-radius:50%; 
163	background-color:white;
164	width:600px;
165	height:400px;
166}
167
168/* Footer area*/
169
170#footer{
171	margin-top:30px;
172	position:relative;
173	background-color:rgb(87, 209, 204);
174	color:inherit;
175	padding:30px;
176	width:100%;
177	height:10px;
178}