body {
    font-family: sans-serif;
}
#container {
    background: #DDD;
    max-width: 1000px;
}
button {
    font-size: 18px;
}
.user-head .inbox-avatar {
    float: left;
    width: 40px;
}
.user-head .inbox-avatar img {
    border-radius: 4px;
}
#principal { 
   margin:0 auto; 
}
.contenedorfoto { 
   float:left; 
   margin: 10px; 
   padding:5px; 
}