Use the provided CSS classes from WordPress
Add the following call in the functions.php file of your current theme, if not already part of it.
// Add support for responsive embed blocks. add_theme_support( 'responsive-embeds' ); |
(This adds the ‘wp-embed-responsive’ CSS class to the <body> of your posts.)
You can use the provided CSS classes with the following syntax in your posts.
< figure class = "wp-has-aspect-ratio wp-embed-aspect-16-9" > < div class = "wp-block-embed__wrapper" > < iframe ...></ iframe > </ div > </ figure > |
Link: /wp-includes/blocks/embed/style.css (on GitHub)
Alternative: Add your own CSS classes to the current theme
Add the following code at the end of the style.css file with an FTP client or the in-house editor.
/*-------------------------------------------------------------- # - Responsive iframe --------------------------------------------------------------*/ .res-con { /* responsive-container */ position : relative ; width : 100% ; padding-top : 56.25% ; /* 16:9 Aspect Ratio */ } .res-con.ar -16 -9 { padding-top : 56.25% ; /* 16:9 Aspect Ratio */ } .res-con.ar -4 -3 { padding-top : 75% ; /* 4:3 Aspect Ratio */ } .res-con iframe { position : absolute ; top : 0 ; left : 0 ; width : 100% ; height : 100% ; } |
(The default aspect ratio is 16:9, so you don’t have to add ‘ar-16-9’.)
You can use the added CSS classes with the following syntax in your posts.
< div class = "res-con ar-16-9" > < iframe ...></ iframe > </ div > |