* {
    margin: 0;
    padding: 0;
}
html {
    background-color: #fff;
    height: 100%;
}
header {
    background-color:rgba(33, 33, 33, 0.9);
    color:#fff;
    display:block;
    font: 14px/1.3 Arial,sans-serif;
    height:50px;
    position:relative;
}
header h2{
    font-size: 22px;
    margin: 0px auto;
    padding: 10px 0;
    width: 80%;
    text-align: center;
}
header a, a:visited {
    text-decoration:none;
    color:#fcfcfc;
}

.calculator {
    /*css3 gradient*/
    background: #e2e2e2; /* Old browsers */
    background: -moz-linear-gradient(top,  #e2e2e2 0%, #dbdbdb 50%, #d1d1d1 51%, #fefefe 100%); /* FF3.6+ */
    background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,#e2e2e2), color-stop(50%,#dbdbdb), color-stop(51%,#d1d1d1), color-stop(100%,#fefefe)); /* Chrome,Safari4+ */
    background: -webkit-linear-gradient(top,  #e2e2e2 0%,#dbdbdb 50%,#d1d1d1 51%,#fefefe 100%); /* Chrome10+,Safari5.1+ */
    background: -o-linear-gradient(top,  #e2e2e2 0%,#dbdbdb 50%,#d1d1d1 51%,#fefefe 100%); /* Opera 11.10+ */
    background: -ms-linear-gradient(top,  #e2e2e2 0%,#dbdbdb 50%,#d1d1d1 51%,#fefefe 100%); /* IE10+ */
    background: linear-gradient(to bottom,  #e2e2e2 0%,#dbdbdb 50%,#d1d1d1 51%,#fefefe 100%); /* W3C */
    filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#e2e2e2', endColorstr='#fefefe',GradientType=0 ); /* IE6-9 */

    display: block;
    margin: 20px auto 0;
    padding: 20px;
    position: relative;
    width: 340px;

    /*css3 border radius*/
    border-radius: 5px;
    -webkit-border-radius: 5px;
    -moz-border-radius: 5px;

    /*css3 shadow*/
    -webkit-box-shadow: 7px 7px 5px rgba(50, 50, 50, 0.75);
    -moz-box-shadow:    7px 7px 5px rgba(50, 50, 50, 0.75);
    box-shadow:         7px 7px 5px rgba(50, 50, 50, 0.75);
}
.calculator button {
    background-color: #eeeeee;
    background-image: -webkit-gradient(linear, left top, left bottom, color-stop(0%, #eeeeee), color-stop(100%, #cccccc));
    background-image: -webkit-linear-gradient(top, #eeeeee, #cccccc);
    background-image: -moz-linear-gradient(top, #eeeeee, #cccccc);
    background-image: -ms-linear-gradient(top, #eeeeee, #cccccc);
    background-image: -o-linear-gradient(top, #eeeeee, #cccccc);
    background-image: linear-gradient(top, #eeeeee, #cccccc);
    border: 1px solid #ccc;
    border-bottom: 1px solid #bbb;
    border-radius: 3px;
    -webkit-border-radius: 3px;
    -moz-border-radius: 3px;
    color: #333;
    font: bold 11px/1 "Lucida Grande", "Lucida Sans Unicode", "Lucida Sans", Geneva, Verdana, sans-serif;
    margin: 5px;
    padding: 8px 0;
    text-align: center;
    text-shadow: 0 1px 0 #eee;
    width: 100px;
}
.calculator button:hover {
    background-color: #dddddd;
    background-image: -webkit-gradient(linear, left top, left bottom, color-stop(0%, #dddddd), color-stop(100%, #bbbbbb));
    background-image: -webkit-linear-gradient(top, #dddddd, #bbbbbb);
    background-image: -moz-linear-gradient(top, #dddddd, #bbbbbb);
    background-image: -ms-linear-gradient(top, #dddddd, #bbbbbb);
    background-image: -o-linear-gradient(top, #dddddd, #bbbbbb);
    background-image: linear-gradient(top, #dddddd, #bbbbbb);
    border: 1px solid #bbb;
    border-bottom: 1px solid #999;
    cursor: pointer;
    text-shadow: 0 1px 0 #ddd;
}
.calculator button:active {
    border: 1px solid #aaa;
    border-bottom: 1px solid #888;
    -webkit-box-shadow: inset 0 0 5px 2px #aaaaaa, 0 1px 0 0 #eeeeee;
    box-shadow: inset 0 0 5px 2px #aaaaaa, 0 1px 0 0 #eeeeee;
}
.calculator p {
    margin-bottom: 15px;
    text-align: center;
}
.calculator h3 {
    background-color: rgba(255, 255, 255, 0.4);
    height: 23px;
    margin-bottom: 10px;
    padding: 8px;
    text-align: right;
}
.calculator div {
    background-color: rgba(255, 255, 255, 0.4);
    margin-bottom: 10px;

    /*css3 border radius*/
    border-radius: 5px;
    -webkit-border-radius: 5px;
    -moz-border-radius: 5px;
}