//浏览器前缀
background: linear-gradient(red, blue);
background: -webkit-linear-gradient(red, blue);
background: -o-linear-gradient(red, blue);
background: -moz-linear-gradient(red, blue);

background:-webkit-linear-gradient(to top, red, blue); 
background:linear-gradient(to top,red,blue);

background:-webkit-linear-gradient(to bottom, red, blue); 
background:linear-gradient(to bottom,red,blue);

background:-webkit-linear-gradient(to right, red, blue); 
background:linear-gradient(to right,red,blue);

background:-webkit-linear-gradient(to right, red, blue); 
background:linear-gradient(to right,red,blue);

background:-webkit-linear-gradient(to right, red, blue); 
background:linear-gradient(to right,red,blue);

background:-webkit-linear-gradient(to right, red, blue); 
background:linear-gradient(to right,red,blue);