背景圖像不與HTML5樣板

Question

工作從開箱即用HTML5樣板安裝的，我用下面的代碼

body 
{ 
background-image:url('img/bg.png'); 
background-repeat:repeat-y; 
} 

在style.css文件和背景圖像不會出現，它仍然保持空白。

完整的CSS是這裏

/* HTML5 Boilerplate */ 

article, aside, details, figcaption, figure, footer, header, hgroup, nav, section { display: block; } 
audio, canvas, video { display: inline-block; *display: inline; *zoom: 1; } 
audio:not([controls]) { display: none; } 
[hidden] { display: none; } 

html { font-size: 100%; -webkit-text-size-adjust: 100%; -ms-text-size-adjust: 100%; } 
html, button, input, select, textarea { font-family: sans-serif; color: #222; } 
body { margin: 0; font-size: 1em; line-height: 1.4; background-image:url('img/bg.png'); 
background-repeat:repeat-xy; } 

::-moz-selection { background: #fe57a1; color: #fff; text-shadow: none; } 
::selection { background: #fe57a1; color: #fff; text-shadow: none; } 

a { color: #00e; } 
a:visited { color: #551a8b; } 
a:hover { color: #06e; } 
a:focus { outline: thin dotted; } 
a:hover, a:active { outline: 0; } 
abbr[title] { border-bottom: 1px dotted; } 
b, strong { font-weight: bold; } 
blockquote { margin: 1em 40px; } 
dfn { font-style: italic; } 
hr { display: block; height: 1px; border: 0; border-top: 1px solid #ccc; margin: 1em 0; padding: 0; } 
ins { background: #ff9; color: #000; text-decoration: none; } 
mark { background: #ff0; color: #000; font-style: italic; font-weight: bold; } 
pre, code, kbd, samp { font-family: monospace, serif; _font-family: 'courier new', monospace; font-size: 1em; } 
pre { white-space: pre; white-space: pre-wrap; word-wrap: break-word; } 

q { quotes: none; } 
q:before, q:after { content: ""; content: none; } 
small { font-size: 85%; } 
sub, sup { font-size: 75%; line-height: 0; position: relative; vertical-align: baseline; } 
sup { top: -0.5em; } 
sub { bottom: -0.25em; } 

ul, ol { margin: 1em 0; padding: 0 0 0 40px; } 
dd { margin: 0 0 0 40px; } 
nav ul, nav ol { list-style: none; list-style-image: none; margin: 0; padding: 0; } 

img { border: 0; -ms-interpolation-mode: bicubic; vertical-align: middle; } 
svg:not(:root) { overflow: hidden; } 
figure { margin: 0; } 

form { margin: 0; } 
fieldset { border: 0; margin: 0; padding: 0; } 

label { cursor: pointer; } 
legend { border: 0; *margin-left: -7px; padding: 0; white-space: normal; } 
button, input, select, textarea { font-size: 100%; margin: 0; vertical-align: baseline; *vertical-align: middle; } 
button, input { line-height: normal; } 
button, input[type="button"], input[type="reset"], input[type="submit"] { cursor: pointer; -webkit-appearance: button; *overflow: visible; } 
button[disabled], input[disabled] { cursor: default; } 
input[type="checkbox"], input[type="radio"] { box-sizing: border-box; padding: 0; *width: 13px; *height: 13px; } 
input[type="search"] { -webkit-appearance: textfield; -moz-box-sizing: content-box; -webkit-box-sizing: content-box; box-sizing: content-box; } 
input[type="search"]::-webkit-search-decoration, input[type="search"]::-webkit-search-cancel-button { -webkit-appearance: none; } 
button::-moz-focus-inner, input::-moz-focus-inner { border: 0; padding: 0; } 
textarea { overflow: auto; vertical-align: top; resize: vertical; } 
input:valid, textarea:valid { } 
input:invalid, textarea:invalid { background-color: #f0dddd; } 

table { border-collapse: collapse; border-spacing: 0; } 
td { vertical-align: top; } 

.chromeframe { margin: 0.2em 0; background: #ccc; color: black; padding: 0.2em 0; } 









@media only screen and (min-width: 35em) { 


} 

.ir { display: block; border: 0; text-indent: -999em; overflow: hidden; background-color: transparent; background-repeat: no-repeat; text-align: left; direction: ltr; *line-height: 0; } 
.ir br { display: none; } 
.hidden { display: none !important; visibility: hidden; } 
.visuallyhidden { border: 0; clip: rect(0 0 0 0); height: 1px; margin: -1px; overflow: hidden; padding: 0; position: absolute; width: 1px; } 
.visuallyhidden.focusable:active, .visuallyhidden.focusable:focus { clip: auto; height: auto; margin: 0; overflow: visible; position: static; width: auto; } 
.invisible { visibility: hidden; } 
.clearfix:before, .clearfix:after { content: ""; display: table; } 
.clearfix:after { clear: both; } 
.clearfix { *zoom: 1; } 

@media print { 
    * { background: transparent !important; color: black !important; box-shadow:none !important; text-shadow: none !important; filter:none !important; -ms-filter: none !important; } 
    a, a:visited { text-decoration: underline; } 
    a[href]:after { content: " (" attr(href) ")"; } 
    abbr[title]:after { content: " (" attr(title) ")"; } 
    .ir a:after, a[href^="javascript:"]:after, a[href^="#"]:after { content: ""; } 
    pre, blockquote { border: 1px solid #999; page-break-inside: avoid; } 
    thead { display: table-header-group; } 
    tr, img { page-break-inside: avoid; } 
    img { max-width: 100% !important; } 
    @page { margin: 0.5cm; } 
    p, h2, h3 { orphans: 3; widows: 3; } 
    h2, h3 { page-break-after: avoid; } 
} 

body 
{ 
background-image:url('img/bg.png'); 
background-repeat:repeat-y; 
} 

Answer 1

HTML5 Boilerplate的目錄結構就需要這樣的：

body { 
    background-image:url(../img/bg.png); 
    background-repeat:repeat-y; 
} 

由於樣式表是/css和圖像爲/img（未/css/img）