purecss-components/dist/bundles/modal.css

Pure.CSS Components is a responsive lib of CSS Only components built to work with Pure.CSS

.pcssc-modal .open-modal:checked~.modal-container{display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-justify-content:center;-ms-flex-pack:center;justify-content:center;-webkit-align-items:center;-ms-flex-align:center;align-items:center}.pcssc-modal .modal-container{position:fixed;width:100%;height:100%;top:0;left:0;background:rgba(2,2,2,.8);z-index:2000}.pcssc-modal .modal-container .modal-frame{width:50%;height:50%}.pcssc-modal .modal-container .modal-frame .modal-header{text-align:center;position:relative;border-top-left-radius:10px;border-top-right-radius:10px}.pcssc-modal .modal-container .modal-frame .modal-body{border-bottom-left-radius:10px;border-bottom-right-radius:10px}