Блог

 const modal = document.querySelector('.modal');
const overlay = document.querySelector('.overlay');
const btnCloseModal = document.querySelector('.close-modal');
const btnOpenModal = document.querySelector('.show-modal');

const openModal = function () {
  //   console.log('Button clicked');
  modal.classList.remove('hidden');
  overlay.classList.remove('hidden');
};

const closeModal = function () {
  modal.classList.add('hidden');
  overlay.classList.add('hidden');
};

btnOpenModal.addEventListner('click', openModal);
btnCloseModal.addEventListner('click', closeModal) 

 *{
margin: 0;
padding: 0; box-sizing: inherit;
}
html {
  font-size: 62.5%;
  box-sizing: border-box;
}
body {
  font-family: sans-serif;
  color: #333;
  line-height: 1.5;
  height: 100vh;
  position: relative;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  background: linear-gradient(to top left, #28b487, #7dd56f);
}
.show-modal {
  font-size: 2rem;
  font-weight: 600;
  padding: 1.75rem 3.5rem;
  margin: 5rem 2rem;
  border: none;
  background-color: #fff;
  color: #444;
  border-radius: 10rem;
  cursor: pointer;
}
.close-modal {
  position: absolute;
  top: 1.2rem;
  right: 2rem;
  font-size: 5rem;
  color: #333;
  cursor: pointer;
  border: none;
  background: none;
}
h1 {
  font-size: 2.5rem;
  margin-bottom: 2rem;
}
p{
font-size: 1.8rem;
}
/* -------------------------- */
/* CLASSES TO MAKE MODAL WORK */
.hidden {
  display: none;
}
.modal {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 70%;
  background-color: white;
  padding: 6rem;
  border-radius: 5px;
  box-shadow: 0 3rem 5rem rgba(0, 0, 0, 0.3);
  z-index: 10;
}
.overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(3px);
  z-index: 5;
} 

  <button class="show-modal">Show modal</button>
<div class="modal hidden">
<button class="close-modal">amp;times;</button> <h1>I'm a modal window </h1>
<p>
        Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do
eiusmod
 ea
tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim
veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex
commodo consequat. Duis aute irure dolor in reprehenderit in voluptate
velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint
occaecat cupidatat non proident, sunt in culpa qui officia deserunt
mollit anim id est laborum.
</p> </div>
    <div class="overlay hidden"></div>