where to add html media query code example

Example 1: media query

@media only screen and (max-width: 600px) {
  body {
    background-color: lightblue;
  }
}

Example 2: css media query

/* BOOSTRAP MEDIA BREAKPOINTS */
/* Small devices (landscape phones, 576px and up) */
@media (min-width: 576px) {  
  .selector {
  	background-color:#f00;
  }
}
/* Medium devices (tablets, 768px and up) The navbar toggle appears at this breakpoint */
@media (min-width: 768px) {}
/* Large devices (desktops, 992px and up) */
@media (min-width: 992px) {}
/* Extra large devices (large desktops, 1200px and up) */
@media (min-width: 1200px) {}

Example 3: orientation css max and min width media query

<style type="text/css">
    /* default styles here for older browsers. 
       I tend to go for a 600px - 960px width max but using percentages
    */
    @media only screen and (min-width: 960px) {
        /* styles for browsers larger than 960px; */
    }
    @media only screen and (min-width: 1440px) {
        /* styles for browsers larger than 1440px; */
    }
    @media only screen and (min-width: 2000px) {
        /* for sumo sized (mac) screens */
    }
    @media only screen and (max-device-width: 480px) {
       /* styles for mobile browsers smaller than 480px; (iPhone) */
    }
    @media only screen and (device-width: 768px) {
       /* default iPad screens */
    }
    /* different techniques for iPad screening */
    @media only screen and (min-device-width: 481px) and (max-device-width: 1024px) and (orientation:portrait) {
      /* For portrait layouts only */
    }

    @media only screen and (min-device-width: 481px) and (max-device-width: 1024px) and (orientation:landscape) {
      /* For landscape layouts only */
    }
</style>

Example 4: media query

@media only screen and (max-width: 600px) {
  .class {
    // Your CSS
  }
}