body {
  font-family: sans-serif;
  line-height: 1.5;
  max-width: 800px;
  margin: 2em auto;
  padding: 0 1em;
  background-color: #19472A;
  position: relative;
}

body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  opacity: 0.5;
  background-image: url(rosa.jpg);
  background-repeat: no-repeat;
  background-size: cover;
  background-position: center center;
  z-index: -1;
}

#container {
  background-color: #1DB954;
  padding: 1.5em;
  border-radius: 15px;
  margin-top: 1em;
}

h1, h2, h3 {
  font-weight: normal;
  color: #222;
  margin-top: 2em;
}

h1 { font-size: 2.5em; }
h2 { font-size: 1.8em; }
h3 { font-size: 1.4em; }

a {
  color: #0077cc;
}

.sidebar {
  margin-top: 3em;
  padding-top: 1em;
  border-top: 1px solid #ddd;
}

.sidebar ul {
  padding-left: 0;
  list-style: none;
}

.sidebar li {
  margin-bottom: 0.5em;
}