.btn-b {
width:100%;
padding: 5px;
color: #111111;
text-decoration: none;
border-radius: 3px;
border-color: #2A73A6 #165899 #07428F;
border-style: solid;
border-width: 1px;
color: #ffffff;
text-shadow: 0 -1px 1px #3275BC;
background: #52a8e8;
padding: 5px;
background: -moz-linear-gradient(top, #52a8e8 0%, #377ad0 100%);
background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,#52a8e8), color-stop(100%,#377ad0));
background: -webkit-linear-gradient(top, #52a8e8 0%,#377ad0 100%);
background: -o-linear-gradient(top, #52a8e8 0%,#377ad0 100%);
background: -ms-linear-gradient(top, #52a8e8 0%,#377ad0 100%);
background: linear-gradient(top, #52a8e8 0%,#377ad0 100%);
filter: progid:DXImageTransform.Microsoft.gradient( startColorstr=’#52a8e8′, endColorstr=’#377ad0′,GradientType=0 );
cursor: pointer;
}

.btn-b:hover {
border-radius: 3px;
border-color: #2A73A6 #165899 #07428F;
border-style: solid;
border-width: 1px;
box-shadow: 0 1px 0 0 #62B1E9 inset;
text-shadow: 0 -1px 1px #1D62AB;
background: #3e9ee5;
background: -moz-linear-gradient(top, #3e9ee5 0%, #206bcb 100%);
background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,#3e9ee5), color-stop(100%,#206bcb));
background: -webkit-linear-gradient(top, #3e9ee5 0%,#206bcb 100%);
background: -o-linear-gradient(top, #3e9ee5 0%,#206bcb 100%);
background: -ms-linear-gradient(top, #3e9ee5 0%,#206bcb 100%);
background: linear-gradient(top, #3e9ee5 0%,#206bcb 100%);
filter: progid:DXImageTransform.Microsoft.gradient( startColorstr=’#3e9ee5′, endColorstr=’#206bcb’,GradientType=0 );

}

.btn-b:hover {
text-decoration: none;
}

.btn-b:active {
-moz-border-bottom-colors: none;
-moz-border-image: none;
-moz-border-left-colors: none;
-moz-border-right-colors: none;
-moz-border-top-colors: none;
background: none repeat scroll 0 0 #3282D3;
border-color: #154C8C #154C8C #0E408E;
border-style: solid;
border-width: 1px;
box-shadow: 0 0 6px 3px #1657B5 inset, 0 1px 0 0 #FFFFFF;
text-shadow: 0 -1px 1px #2361A4;
}

#contenido{
width:90%;
margin-left:5%;
}