play.css

body {
  background: #ccc;
  font-size: 18;
}
.contenedor {
  width: 780px;
  min-height: 50px;
  background: white;
  margin: 0 auto;
}
.cabecera {
  background: grey;
  width: 780px;
  height: 50px;
}
.menu {
  width: 100%;
  height: 40px;
  padding: 0;
  margin: 0;
  list-style: none;
}
.menu li {
  display: inline-block;
}
.menu li a {
  padding: 10px 10px;
  display: inline-block;
  color: white;
}
.menu li a:hover {
  background-color: #3adf00;
}
.slider {
  margin: 0 auto;
  width: 780px;
  height: 370px;
  background: white;
}
.slider h2 {
  margin-left: 320px;
}
.slider img {
  margin-left: 260px;
}
.slider a {
  margin-left: 350px;
  color: #3adf00;
  font-size: 16;
}
.footer {
  margin: 0 auto;
  width: 780px;
  background: black;
  height: 50px;
  margin-bottom: 0px
}
.footer p {
  margin-top: auto;
  font-size: 14px;
  color: #ccc
}