header {
    text-align: left;
}

h3 {
    margin-left: 3%;
    background-color: lightskyblue;
    text-shadow: 0 2px 2px darkgrey;
    border-radius: 5px;
    color: white;
    font-family: sans-serif;
    font-size: 20px;
    padding: 5px;
    width: 433px;
}

footer {
    position:fixed; 
    bottom: 0px;
    width: 100%;  
}

.formulario ul {
    width:750px;
    list-style-type:none;
    margin:0px;
    padding:0px;
}

.formulario li {
    padding:12px;
    border-bottom:1px solid #eee;
}

.obligatorio:after {
    content: '*';
    color: red;
}

.formulario input:valid, .formulario textarea:valid {
    box-shadow: 0 0 5px green;
    border-color: green;
}

.formulario input:required:invalid, .formulario textarea:required:invalid {
    box-shadow: 0 0 5px red;
    border-color: red;
}

.formulario label {
    display: inline-block;
    float: left;
    font-family: sans-serif;
    font-size: 15px;
    font-weight: bold;
    margin-top: 3px;
    padding: 3px;
    width: 90px;
}

.formulario input {
   height:20px;
   width:220px;
   padding:5px 8px;
}

.formulario textarea {
   padding:8px;
   width:300px;
}

.formulario button {
   margin-left:90px;
}

.formulario input, .formulario textarea {
    border:1px solid #aaa;
    border-radius: 5px;
    color: #888;
    font-size: 12px;
    padding-right:30px;
    -moz-transition: padding .25s;
    -webkit-transition: padding .25s;
    -o-transition: padding .25s;
    transition: padding .25s;
}

.formulario input:focus, .formulario textarea:focus {
    background: #fff;
    border:1px solid #555;
    box-shadow: 0 0 3px #aaa;
    padding-right:120px;
}

button.submit {
    padding: 9px 17px;
    font-family: Helvetica, Arial, sans-serif;
    font-weight: bold;
    line-height: 1;
    color: #444;
    border: none;
    background-color: #fff;
    border: 1px solid #f1f1f1;
    border-radius: 10px;
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.5);
}

button.submit:hover {
   opacity:.55;
   cursor: pointer;
   color: red;
}

button.submit:active {
   border: 5px solid #222;
   box-shadow: 0 0 10px 5px #444 inset;
}