/*
 * The MIT License
 * Copyright (c) 2012 Matias Meno <m@tias.me>
 */
.dropzone, .dropzone * {
  box-sizing: border-box; }

.dropzone {
  position: relative; }
  .dropzone .dz-preview {
    position: relative;
    display: inline-block;
    width: 120px;
    margin: 0.5em; }
    .dropzone .dz-preview .dz-progress {
      display: block;
      height: 15px;
      border: 1px solid #aaa; }
      .dropzone .dz-preview .dz-progress .dz-upload {
        display: block;
        height: 100%;
        width: 0;
        background: green; }
    .dropzone .dz-preview .dz-error-message {
      color: red;
      display: none; }
    .dropzone .dz-preview.dz-error .dz-error-message, .dropzone .dz-preview.dz-error .dz-error-mark {
      display: block; }
    .dropzone .dz-preview.dz-success .dz-success-mark {
      display: block; }
    .dropzone .dz-preview .dz-error-mark, .dropzone .dz-preview .dz-success-mark {
      position: absolute;
      display: none;
      left: 30px;
      top: 30px;
      width: 54px;
      height: 58px;
      left: 50%;
      margin-left: -27px; }


style.css

body {
    font-family: Arial, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
    background-color: #f0f0f0;
  }

  .drop-zone {
    width: 300px;
    height: 200px;
    border: 2px dashed #007bff;
    border-radius: 4px;
    display: flex;
    justify-content: center;
    align-items: center;
    text-align: center;
    color: #007bff;
    cursor: pointer;
    transition: background-color 0.2s ease;
  }