To make the pop-ups inside your website more beautiful, you can use those that have a special style. Like this code, which is a pop-up with a blue style and buttons that have no background and only white border. This pop-up has a close button with its icon. The text in this pop-up is white. The theme of the button that pops up when clicked is also blue and white.


HTML
<!-- This script got from www.devanswer.com  -->
<div class="modal-container-bode">
  <a href="#modal-opened" class="link-1" id="modal-closed">Open Modal</a>
  <div class="modal-container" id="modal-opened">
    <div class="modal">
      <div class="modal__details">
        <h1 class="modal__title">Modal Title</h1>
        <p class="modal__description">orem ipsum dolor sit amet, consectetur adipisicing elit.</p>
      </div>
      <p class="modal__text">Lorem ipsum dolor sit amet, consectetur adipisicing elit. Facilis ex dicta maiores libero minus obcaecati iste optio, eius labore repellendus.</p>
      <button class="modal__btn">Button &rarr;</button>
      <a href="#modal-closed" class="link-2"></a>
    </div>
  </div>
  <a class="abs-site-link" href="" target="_blank">This pop-up is made with CSS and Target Selector</a>
</div><div id="bcl"><a style="font-size:8pt;text-decoration:none;" href="http://www.devanswer.com ">Developers Answer</a></div>
                        

CSS
*,*::after,*::before {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
html {
  font-size: 62.5%;
}
.modal-container-bode {
  --light: hsl(0, 0%, 100%);
  --background: linear-gradient(to right bottom, hsl(236, 50%, 50%), hsl(195, 50%, 50%));
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Open Sans', sans-serif;
  min-height: 100vh;
  background: linear-gradient(to bottom, hsl(236, 50%, 98%), hsl(236, 50%, 94%));
}
a,
a:link {
  font-family: inherit;
  text-decoration: none;
}
.modal-container {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 10;
  display: none;
  justify-content: center;
  align-items: center;
  width: 100%;
  height: 100%;
  background: hsla(0, 0%, 40%, .6);
}
.modal-container:target {
  display: flex;
}
.modal {
  width: 60rem;
  padding: 4rem 2rem;
  border-radius: .8rem;
  color: var(--light);
  background: var(--background);
  box-shadow: .4rem .4rem 2.4rem .2rem hsla(236, 50%, 50%, 0.3);
  position: relative;
  overflow: hidden;
}
.modal__details {
  text-align: center;
  margin-bottom: 4rem;
  padding-bottom: 4rem;
  border-bottom: 1px solid hsla(0, 0%, 100%, .4);
}
.modal__title {
  font-size: 3.2rem;
}
.modal__description {
  margin-top: 2rem;
  font-size: 1.6rem;
  font-style: italic;
}
.modal__text {
  padding: 0 4rem;
  margin-bottom: 4rem;
  font-size: 1.6rem;
  line-height: 2;
}
.modal__text::before {
  content: '';
  position: absolute;
  top: 0%;
  left: 100%;
  transform: translate(-50%, -50%);
  width: 18rem;
  height: 18rem;
  border: 1px solid hsla(0, 0%, 100%, .2);
  border-radius: 100rem;
  pointer-events: none;
}
.modal__btn {
  padding: 1rem 1.6rem;
  border: 1px solid hsla(0, 0%, 100%, .4);
  border-radius: 100rem;
  color: inherit;
  background: transparent;
  font-size: 1.4rem;
  font-family: inherit;
  letter-spacing: .2rem;
  transition: .2s;
  cursor: pointer;
}
.modal__btn:hover,
.modal__btn:focus {
  border-color: hsla(0, 0%, 100%, .6);
  transform: translateY(-.2rem);
}
.link-1 {
  font-size: 1.8rem;
  color: var(--light);
  background: var(--background);
  box-shadow: .4rem .4rem 2.4rem .2rem hsla(236, 50%, 50%, 0.3);
  border-radius: 100rem;
  padding: 1.4rem 3.2rem;
  transition: .2s;
}
.link-1:hover,
.link-1:focus {
  transform: translateY(-.2rem);
  box-shadow: 0 0 4.4rem .2rem hsla(236, 50%, 50%, 0.4);
}
.link-2 {
  width: 4rem;
  height: 4rem;
  border: 1px solid hsla(0, 0%, 100%, .4);
  border-radius: 100rem;
  color: inherit;
  font-size: 2.2rem;
  position: absolute;
  top: 2rem;
  right: 2rem;
  display: flex;
  justify-content: center;
  align-items: center;
  transition: .2s;
}
.link-2::before {
  content: '×';
  transform: translateY(-.1rem);
}
.link-2:hover,
.link-2:focus {
  border-color: hsla(0, 0%, 100%, .6);
  transform: translateY(-.2rem);
}
.second-version-link,
.second-version-link:link {
  color: hsl(236, 50%, 50%);
  padding: .8rem 1.6rem .8rem .2rem;
  border-bottom: 2px solid hsl(236, 50%, 50%);
  font-size: 1.4rem;
  font-weight: bold;
  position: absolute;
  top: 4rem;
  right: 4rem;
}
.second-version-link::after {
  content: '\2197';
  position: absolute;
  top: 0;
  right: 0;
  font-size: .9em;
}
a#modal-closed:focus-visible {
  border: 0;
  outline: 0;
}
.abs-site-link {
  position: fixed;
  top: 20px;
  text-align: center;
  width: 100%;
  font-size: 16px;
  color: hsla(0, 0%, 0%, .6);
  font-size: 1.6rem;
}