main.css

body { padding: 0; margin: 0 auto;  }
#app { }

/* Style Unresolved (as opposed to Unknown) elements */
:unresolved { border: 5px dashed #C00; display: block; margin: 2em; padding: .5em; }

/* Custom element styles */
mmmbop-title { 
    display:block; border-bottom: 1px solid #000; 
    padding:.75em 0; text-align: center; font-size: 1.5em;
}
mmmbop-title /deep/ span { }
mmmbop-welcome { display: block; text-align: right; margin-top: .25em;}
mmmbop-menu { font-size: 1em;  }

.examples { display: block; border: 1px solid #000; margin: 0 2em; text-align: center; }

/* Demonstrate the closed nature of web components */
a { font-weight: bold; color: blue; }

/* Style an unknown element */
song { display: block; padding:.5em; background-color: #FCC; color: #900; font-weight: bold; text-decoration: line-through; }