Dawn Theme: PopUp Without Additional Apps

Create pop-up.liquid file in Theme > Edit code > Sections folder, then past this code into that file

Open Popup

  

    ## {{ section.settings.title }}
    ×
    

      {{ section.settings.content }}
    

  

{% schema %}
  {
    "name": "Popup",
    "settings": [
      {
        "id": "trigger",
        "type": "text",
        "label": "ID",
        "info": "Unique ID for popup trigger"
      },
      {
        "id": "title",
        "type": "text",
        "label": "Title"
      },
      {
        "id": "content",
        "type": "richtext",
        "label": "Content"
      }
    ],
    "presets": [{
      "name": "Popup",
      "category": "Window"
    }]
  }
{% endschema %}

{% stylesheet %}
  .popup__overlay {
    position: fixed;
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    background: rgb(0, 0, 0, 0.7);
    transition: opacity 500ms ease-in-out;
    visibility: hidden;
    opacity: 0;
  }

  .popup__overlay:target {
    visibility: visible;
    opacity: 1;
    z-index: 99;
  }

  .popup__box {
    padding: 24px;
    background: #fff;
    border-radius: 8px;
    width: 40%;
    position: relative;
  }

  .popup__box h2 {
    color: #333;
    font-size: 2em;
    font-weight: bold;
    font-family: Verdana, sans-serif;
    margin-top: 0;
  }

  .popup__close {
    position: absolute;
    top: 20px;
    right: 30px;
    transition: all 200ms ease-out;
    color: #333;
    font-size: 30px;
    font-weight: bold;
    line-height: 1.25;
    text-decoration: none;
  }

  .popup__close:hover {
    color: #660000;
  }

  .popup__content {
    max-height: 30%;
    overflow: auto;
  }

  @media screen and (max-width: 1280px) {
    .popup__box {
      width: 60%;
    }
  }

  @media screen and (max-width: 720px) {
    .popup__box {
      width: 80%;
    }
  }
{% endstylesheet %}

{% javascript %}
{% endjavascript %}

Try it and let me know