.container {
  display: flex;
  flex-wrap: nowrap;
  background-color: DodgerBlue;
}
.main {
  background-color: #f1f1f1;
  flex: 2.7;
  margin: 50px;
  line-height: auto;
  font-size: 30px;
}

.sidebar{
    flex: 1;
    margin: 50px;
    padding: 20px;
    background-color: #f1f1f1
}
body {
  background-color: green;
}


h1   {
  font-size: 45px;
  font-family: 'Roboto',sans-serif;
  color: red;
}


h2   {
  color: red;
}


p    {
  color: blue;
  border: 2px solid red; 
  padding: 20px;
  margin: 20px;
  background-color: white;
}

a {
  color: red;
}
* {
    box-sizing: border-box
}