.mb-base {
  position: fixed;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.85);
  z-index: 3;
  display: none; }
  .mb-base .mb-contents {
    max-width: 800px;
    height: auto;
    position: absolute;
    left: 50%;
    top: 50%;
    -webkit-transform: translate(-50%, -50%);
    -ms-transform: translate(-50%, -50%);
    transform: translate(-50%, -50%); }
    .mb-base .mb-contents span.mb-close {
      position: absolute;
      right: -15px;
      top: -15px;
      width: 30px;
      height: 30px;
      border-radius: 50%;
      background: #fff;
      color: #000;
      text-align: center;
      font-size: 20px;
      cursor: pointer;
      line-height: 26px; }
    .mb-base .mb-contents .mb-arrange img,
    .mb-base .mb-contents .mb-arrange video {
      border: none;
      max-width: 100%;
      height: auto; }