How can I determine the corners of the video player differently (rounded/square)?

Hello, I need help with a small detail on my website. I would like to have the top corners of a specific video player square and the bottom corners rounded. How can I achieve this for this individual video? I've already inserted a CSS code that rounds all video corners. Looking forward to your assistance!

Site: https://maltemartenmethod.squarespace.com/
Paword: maltemartenmethod2023

Change this code

.plyr__video-wrapper video, .plyr__video-wrapper, .sqs-video-overlay {
    border-radius: 15px !important;
}

to this

div#block-2ec7ed9ce3f9d0b6acb6 {
video, .plyr__video-wrapper, .sqs-video-overlay {
    border-radius: 15px !important;
}}

Use this free tool to find video block id https://chrome.google.com/webstore/detail/squarespace-id-finder/igjamfnifnkmecjidfbdipieoaeghcff