단락의 불투명도

Question

내 단락의 불투명도를이 사이트와 비슷하게 설정하고 있지만 내 div에서 불투명도 0.1을 사용하면 텍스트가 불투명도가 1이되고 두 div가 설정되었지만 여전히 그렇지 않습니다. 이 사이트와 동일 http://www.infosys.com/about/Pages/index.aspx. 내 http://jsfiddle.net/5v3p7/. 이 같은 RGBA와

Here is my html: 
<!DOCTYPE.html> 

</html> 

<div id="center"> 

<div id="content"> 


<div id="text"> 
Building Tomorrow’s Enterprise 

Infosys is a global leader in consulting, technology and outsourcing solutions. As a proven partner focused on building tomorrow's enterprise, Infosys enables clients in more than 30 countries to outperform the competition and stay ahead of the innovation curve. With US$8.095bn in LTM Q3 FY14 revenues and 158,000+ employees, Infosys provides enterprises with strategic insights on what lies ahead. We help enterprises transform and thrive in a changing world through strategic consulting, operational leadership and the co-creation of breakthrough solutions, including those in mobility, sustainability, big data and cloud computing. 

Learn more about how Infosys is Building Tomorrow’s Enterprise 
Learn more about industry solutions from Infosys. 
Learn more about services from Infosys 
Learn more about products from Infosys 

</div> 


</div> 

</div> 

<div id="img"> 

<img src="http://hoklife.com/wp-content/uploads/2009/02/office-1.jpg"> 
</div> 


Here is my css: 
html 
{ 
background:blue; 
} 
#content 
{ 
position:relative; 
z-index:1; 
background:black; 
color:silver; 
min-height:1000px; 
opacity:0.5; 
font-size:40px; 
width:960px; 
margin-right:auto; 
margin-left:auto; 
padding:20px; 
} 
#text 
{ 
position:relative; 
z-index:3; 
color:white; 
min-height:500px; 
opacity:10; 
width:500px; 
font-size:40px; 
} 
#img 
{ 
position:fixed; 
top:-50%; 
left:-50%; 
height:200%; 
width:200%; 
} 
#img img 
{ 
position:absolute; 
top:0; 
left:0; 
right:0; 
bottom:0; 
margin:auto; 
min-height:50%; 
min-width:50%; 
} 

Answer 1

사용 배경 : -

#content { 
position: relative; 
z-index: 1; 
background: rgba(0, 0, 0, 0.4); 
color: silver; 
min-height: 1000px; 
font-size: 40px; 
width: 960px; 
margin-right: auto; 
margin-left: auto; 
padding: 20px; 
}