Bootstrap 5 Modal: Correct Way to Open Popup Content Display

Bootstrap 5 modals are used for page temporary interactions (such as prompts, confirmations, forms, etc.), covering underlying content to prevent interference. Their advantages include out-of-the-box availability, responsiveness, and flexible control, relying on Popper.js for positioning. Before use, include Bootstrap 5 CSS and JS (including Popper). The core HTML structure consists of a .modal container, which contains .modal-dialog (controlling size and position) and .modal-content (with .header, .body, and .footer). The .header includes a title and a close button, the .body holds the content, and the .footer contains action buttons. To trigger the modal, the button click requires `data-bs-toggle="modal"` and `data-bs-target="#ID"`. Closing methods include clicking the × in the top-right corner, pressing the ESC key, clicking the background, using bottom buttons, or manual control via JS (`new bootstrap.Modal(modalId).show()`). Custom sizes are available (.modal-sm/lg/xl). Note that Popper.js dependency, avoid nesting, prevent duplicate form submissions, and disable scrolling for long content. By mastering the structure, triggering, closing, and customization, you can quickly implement pop-up interactions.