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<html>
<head>
    <meta charset="utf-8">
    <title>Blog - João da Silva</title>
    <link rel="icon" href="favicon.png">
    <link rel="stylesheet" href="http://fonts.googleapis.com/css?family=Crimson+Text:400,400italic,600">
    <link rel="stylesheet" href="http://fonts.googleapis.com/css?family=Open+Sans+Condensed:700">
    <link rel="stylesheet" href="reset.css">
    <link rel="stylesheet" href="site.css">
    <link rel="stylesheet" href="portfolio.css">
</head>
<body>
    <main>
        <h1 class="titulo-principal">Portfolio</h1>
        <div class="container">
            <p>Veja abaixo a lista dos meus projetos mais relevantes:</p>
            <ul class="portfolio">
                <li>
                    <a href="http://bmw.com">
                        <figure>
                        <img src="../Alura/bmw.png" alt="Site da BMW">
                        <figcaption>BMW.com: reformulação de design e implementação de HTML, CSS e JavaScript</figcaption>
                        </figure>
                    </a>    
                </li> 
                <li>
                    <a href="http://g1.com.br">
                        <figure>
                        <img src="../Alura/g1.png" alt="Site da G1">
                        <figcaption>G1.com.br: reformulação de design, CSS e JavaScript</figcaption>
                        </figure>
                    </a>    
                </li> 
                <li>
                    <a href="http://ibm.com">
                        <figure>
                        <img src="../Alura/ibm.png" alt="Site da IBM">
                        <figcaption>IBM.com: aplicação de progressive enhancement em conunto com aplicação back-end</figcaption>
                        </figure>
                    </a>    
                </li> 
                <li>
                    <a href="http://uol.com.br">
                        <figure>
                        <img src="../Alura/uol.png" alt="Site da Uol">
                        <figcaption>UOL.com.br: reformulação de design e implementação de HTML, CSS e JavaScript</figcaption>
                        </figure>
                    </a>    
                </li> 
            </ul>
        </div>    
    </main>
    <img src="../Alura/eu.jpg" alt="Foto João da Silva" class="fotojoao">
    <aside class="navegacao-site">
        <h1>João da Silva</h1>
        <nav>
            <ul>
                <li><a href="index.html">Home</a></li>
                <li><a href="portfolio.html">Portfolio</a></li>
                <li><a href="bio.html">Sobre mim</a></li>
                <li><a href="blog.html">Blog</a></li>
                <li><a href="contato.html">Contato</a></li>    
            </ul>    
        </nav>
        <ul class="icones-sociais">
            <li>
                <a class="github" href="https://github.com/joaodasilva"></a>
                <a class="twitter" href="https://twitter.com/joaodasilva"></a>
                <a class="linkedin" href="https://br.linkedin.com/pub/joão-da-silva/32/4/508"></a>
            </li>    
        </ul>
    </aside>
    <footer class="rodape-pagina">
        &copy; João da Silva 2014
    </footer>
</body>
</html>

Portfolio.css

.portfolio li{
    display: inline-block;
    width: 45%;
    border: 8px solid black;
    background-color: #FAFFFC;
    box-sizing: border-box;
    padding: 16px;
    margin-bottom: 16px;
    margin-right: 16px;
}
.portfolio img{
    width:  100%;
}

site.css

.titulo-principal{
    background-color: #851944;
    color: #fff;
    text-align: center;
    padding: 20px;
    border-bottom: 10px solid black;
    font-size: 60px;
    text-transform: uppercase;
}
main {
    float: left;
    width: 85%;
    padding-bottom: 80px;
}
h1, h2 {
    font-family: "Open Sans Condensed", sans-serif;
}
h2{
    font-size: 30px;
    clear: both;
}
p{
    text-align: justify;
    margin: 20px 0;
}
body{
    font-family: "Crimson Text", serif;
    background-color: #F2FFFC;
    font-size: 120%;
    line-height: 1.5;
}

nav a {
    color: #F2FFFC;
    padding: 20px;
    text-transform: lowercase
}
.navegacao-site{
    background-color: #3C1D3D;
    color: #F2FFFC;
    text-align: center;
    padding: 20px;
    position: relative;
    top: 310px;
    width: 15%;
}

.navegacao-site, .fotojoao {
    float: right;
    box-sizing: border-box;
    border-left: 10px solid black;
    border-bottom: 10px solid black;
}

.rodape-pagina{
    background-color: black;
    color: #F2FFFC;
    padding: 20px;
}
main a{
    color: #851944;
}
aside a{
    color: inherit;
    font-family: "Open Sans Condensed", sans-serif;
}
.fotojoao {
    position: absolute;
    top: 0px;
    right: 0px;
}
aside h1{
    font-size: 30px;
    margin-bottom: 25px;
}
.texto-principal{
    width: 720px;
    margin-left: auto;
    margin-right: auto;
    padding: 40px 0;
}
strong {
    font-weight: bold;
}
em {
    font-style: italic;
}
.icones-sociais a{
    display: inline-block;
    width: 40px;
    height: 40px;
    text-indent: -9999px;
}
.twitter {
    background-image: url(../Alura/twitter.png);
}
.github {
    background-image: url(../Alura/github.png);
}
.linkedin {
    background-image: url(../Alura/linkedin.png);
}

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