style.css

.diffWidget {
  border: 2px solid rgba(1,1,1, 0.3);
  padding: 5px;
}

.diffWidget .wrapper {
  width: 100%;
  height: 100%;
  position: relative;
  z-index: 1;
}

.diffWidget .first {
  position: relative;
  width: 100%;
  height: 100%;
  z-index: 3;
  top: 0;
  left: 0;

  border-right: 1px solid rgba(0, 0, 0, 0.3);
}

.diffWidget .second {
  position: absolute;
  width: 100%;
  height: 100%;
  z-index: 2;
  top: 0;
  left: 0;
}

html {
    margin:    0 auto;
    max-width: 900px;
}
body
{
    width: 100%; 
    text-align: left; 
    margin: 0px auto;
}   

h1 { 
    display: block;
    font-size: 3em;
    font-family: "Andale Mono", monospace; 
    margin-top: 0.67em;
    margin-bottom: 0.67em;
    margin-left: 0;
    margin-right: 0;
    font-weight: normal;
    font-variant: small-caps;
    text-align: center; 
    color: white;

}
h2 { 
    display: block;
    font-size: 1.5em;
    font-family: "Andale Mono", monospace; 
     margin-top: 0.67em;
    margin-bottom: 0.67em;
    margin-left: 0;
    margin-right: 0;
    font-weight: normal;
}
h3 { 
    display: block;
    font-size: 1em;
    margin-top: 0.67em;
    margin-bottom: 0.67em;
    margin-left: 0;
    margin-right: 0;
    font-weight: bold;
}

#big_wrapper { 
    border: 1px solid black;
    width: 100%;
    margin: 20px auto;
    text-align: left;
    padding: 10px;
    background-color: green;

  }

  #titulo {
        border: 1px #3E787B;
        background-color: #3E787B; 
        width: 100%;
        margin: 20px auto;
        padding: 5px;

        text-align: center;


    }