Add rounded borders to selected corners of an element
问题 How could I go about constructing something like this with pure CSS? This is how far I've gotten so far: Fiddle I'm struggling with how to get that rounded corner there, even if I continue to add additional span s. CODE: body { background: #000; } .container { position: relative; width: 300px; height: 150px; margin: 10% auto; } .top-right { position: absolute; top: -10px; right: 0; width: 50px; height: 1px; background: white; border-radius: 5px; } .box { width: 100%; height: 100%; background: