/* Set the background color of body to tan */
body {
  background-color: tan;
}

/* On screens that are 992px or less, set the background color to blue */
@media screen and (max-width: 992px) {
  body {
    background-color: blue;
  }
}

/* On screens that are 600px or less, set the background color to olive */
@media screen and (max-width: 600px) {
  body {
    background-color: olive;
  }
}

 /* The navbar container */
.topnav {
    overflow: hidden;
    background-color: #333;
}

/* Navbar links */
.topnav a {
    float: left;
    display: block;
    color: white;
    text-align: center;
    padding: 14px 16px;
    text-decoration: none;
}

/* On screens that are 600px wide or less, make the menu links stack on top of each other instead of next to each other */
@media screen and (max-width: 600px) {
    .topnav a {
        float: none;
        width: 100%;
    }
} 

/* Create four equal columns that floats next to each other */
.column {
  float: left;
  width: 25%;
}

/* On screens that are 992px wide or less, go from four columns to two columns */
@media screen and (max-width: 992px) {
  .column {
    width: 50%;
  }
}

/* On screens that are 600px wide or less, make the columns stack on top of each other instead of next to each other */
@media screen and (max-width: 600px) {
  .column {
    width: 100%;
  }
}

/* Container for flexboxes */
.row {
  display: flex;
  flex-wrap: wrap;
}

/* Create four equal columns */
.column {
  flex: 25%;
  padding: 20px;
}

/* On screens that are 992px wide or less, go from four columns to two columns */
@media screen and (max-width: 992px) {
  .column {
    flex: 50%;
  }
}

/* On screens that are 600px wide or less, make the columns stack on top of each other instead of next to each other */
@media screen and (max-width: 600px) {
  .row {
    flex-direction: column;
  }
}

/* If the screen size is 600px wide or less, hide the element */
@media screen and (max-width: 600px) {
  div.example {
    display: none;
  }
}

<div> to 80px */
@media screen and (min-width: 600px) {
  div.example {
    font-size: 80px;
  }
}

<div> to 30px */
@media screen and (max-width: 600px) {
  div.example {
    font-size: 30px;
  }
}

* {
    box-sizing: border-box;
}

/* Style the body */
body {
    font-family: Arial;
    margin: 0;
}

/* Header/logo Title */
.header {
    padding: 60px;
    text-align: center;
    background: #1abc9c;
    color: white;
}

/* Style the top navigation bar */
.navbar {
    display: flex;
    background-color: #333;
}

/* Style the navigation bar links */
.navbar a {
    color: white;
    padding: 14px 20px;
    text-decoration: none;
    text-align: center;
}

/* Change color on hover */
.navbar a:hover {
    background-color: #ddd;
    color: black;
}

/* Column container */
.row {  
    display: flex;
    flex-wrap: wrap;
}

/* Create two unequal columns that sits next to each other */
/* Sidebar/left column */
.side {
    flex: 30%;
    background-color: #f1f1f1;
    padding: 20px;
}

/* Main column */
.main {
    flex: 70%;
    background-color: white;
    padding: 20px;
}

/* Fake image, just for this example */
.fakeimg {
    background-color: #aaa;
    width: 100%;
    padding: 20px;
}

/* Footer */
.footer {
    padding: 20px;
    text-align: center;
    background: #ddd;
}

@media only screen and (orientation: landscape) {
    body {
        background-color: lightblue;
    }
}

@media screen and (max-width: 900px) and (min-width: 600px) {
  div.example {
    font-size: 50px;
    padding: 50px;
    border: 8px solid black;
    background: yellow;
  }
}

/* When the width is between 600px and 900px OR above 1100px - change the appearance of <div> */
@media screen and (max-width: 900px) and (min-width: 600px), (min-width: 1100px) {
  div.example {
    font-size: 50px;
    padding: 50px;
    border: 8px solid black;
    background: yellow;
  }
}