.body #input { display: flex; flex-wrap: wrap; justify-content: center; } .body #input > input { justify-self: center; outline: none; padding: 16px; margin: 16px; font-size: 24px; border: 2px solid #2a2a2a; width: 128px; height: 64px; border-radius: 16px; text-align: center; } .body #output { font-size: 24px; text-align: center; } .body #output:empty { display: none; } .body #output::before { content: "Result:"; color: #2a2a2a; padding-right: 0.5em; } .body #error { font-size: 24px; text-align: center; color: #e21c1c; } .body #error:empty { display: none; } .body #error::before { content: "Error:"; color: #e94e4e; padding-right: 0.5em; }