Вопросы по CSS

сss style (+/-)

html{
background-color: #5e9fa5;
}

body{
margin: 20px auto;
padding: 20px;
max-width: 700px;
background: #fff;
-moz-border-radius: 10px;
border-radius: 10px;
}

.l-grad:after, .l-grad:before{
content: '';
position: absolute;
}

.l-grad{
background: #026873;
background-image: -moz-linear-gradient(rgba(255,255,255,.3), rgba(255,255,255,0));
background-image: -webkit-linear-gradient(rgba(255,255,255,.3), rgba(255,255,255,0));
background-image: -o-linear-gradient(rgba(255,255,255,.3), rgba(255,255,255,0));
background-image: -ms-linear-gradient(rgba(255,255,255,.3), rgba(255,255,255,0));
background-image: linear-gradient(rgba(255,255,255,.3), rgba(255,255,255,0));
-moz-border-radius: 7px;
border-radius: 7px;
-moz-box-shadow: 0 2px 0 rgba(0,0,0,.3);
-webkit-box-shadow: 0 2px 0 rgba(0,0,0,.3);
box-shadow: 0 2px 0 rgba(0,0,0,.3);
color: #fff;
font: bold 210%/100% Georgia, "Century Schoolbook L", Serif;
position: relative;
margin: 0 -28px 0px -28px;
padding: 10px 15px;
text-align:center;
text-shadow: 0 1px rgba(0,0,0,1);
clear: both;
}

.l-grad:before, .l-grad:after{
border-style: solid;
border-color: transparent;
bottom: -5px;
}

.l-grad:before{
border-width: 0 5px 5px 3px;
border-right-color: #002a2f;
left: 0;
}

.l-grad:after{
border-width: 0 3px 5px 5px;
border-left-color: #002a2f;
right: 0;
}