@import url(http://fonts.lug.ustc.edu.cn/css?family=Source+Serif+Pro);
body { 
  width: 60%;
  max-width: 900px;
  margin: 0 auto;
  font-family: Source Serif Pro, serif; 
}
#dropcap { initial-letter: 3;  color: red; }
p { line-height: 1.5; font-size: 2rem; }

@media all and (max-width: 600px) { 
#dropcap { initial-letter: 2; }
p { font-size: 1.5rem; } 
body { margin-top: 4rem; }
}