.video-container {
  position: relative;
  padding-bottom: 49%; /* 16:9 比例 */
  height: 0;
  overflow: hidden;
  background-color: #121212;
}
.video-container iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}
.tiPs > a {
  text-decoration: none;
}
body.dark-mode {
  background-color: #121212;
  color: #e0e0e0;
  nav.navbar {
    background-color: #212121;
    color: #e0e0e0;
  }

  div.alert {
    background-color: #303030;
    color: #e0e0e0;
  }

  button.btn {
    background-color: #3f51b5;
    color: #e0e0e0;
  }

  input.form-control {
    background-color: #303030 !important;
    color: #e0e0e0 !important;
  }

  select.form-select {
    background-color: #303030;
    color: #e0e0e0;
  }

  .tiPs > a {
    color: white;
  }
  .msr {
    color: black;
  }
}
.mn3 {
  z-index: 999999;
}
.co-bt {
  color: var(--bs-nav-link-color);
}
.mtop {
  margin: 100px 0 !important;
}
.bg-dark {
  background: #303030 !important;
}
.img-fluid {
  margin: 15px 0 !important;
}