html,
body {
  height: 100%;
}
.bg-video {
  background-size: cover;
  position: fixed;
  right: 0;
  bottom: 0;
  width: 100%;
  height: 100%;
  z-index: -1;
  object-fit: cover; /* 保持视频的宽高比 */
}
.rotating-plane {
  display: none;
  width: 80px;
  height: 80px;
  background: #fff;
  position: absolute;
  left: 50%;
  top: 50%;
  margin-left: -40px;
  margin-top: -40px;
  animation: rotating-plane 2s infinite;
}
.rotating-plane.active {
  display: block;
}
.login {
  width: 350px;
  height: 300px;
  background-color: rgba(255, 255, 255, 0.8); /* 半透明白色背景 */
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2); /* 阴影效果 */
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  padding: 20px;
}
.login.effect {
  animation: login-small 0.8s linear;
  animation-fill-mode: forwards;
}
.login h3 {
  font-size: 24px;
  margin-bottom: 50px;
}
.login .log-form li {
  position: relative;
  width: 100%;
  height: 40px;
  display: flex;
  align-items: center;
  margin-bottom: 20px;
}
.login .log-form li input {
  height: 30px;
  border: 0px;
  border-bottom: 1px solid #ccc;
  flex-grow: 1;
  padding-left: 10px;
  outline: none;
}
.login .log-form li input:focus {
  border: 1px solid dodgerblue;
}
.login .log-form li input:focus ~ label {
  opacity: 1;
  top: -5px;
}
.login .log-form li label {
  position: absolute;
  left: 50px;
  top: 21px;
  color: dodgerblue;
  font-size: 14px;
  opacity: 0;
  background: #fff;
  padding: 0 5px;
  transition: 0.5s;
}
.login .log-form li i {
  width: 20px;
  height: 20px;
  display: inline-block;
  background: red;
  margin-right: 18px;
}
.login .log-form li i.name {
  background: url(../img/name.png) no-repeat;
  background-size: 20px 20px;
}
.login .log-form li i.password {
  background: url(../img/password.png) no-repeat;
  background-size: 20px 20px;
}
.login .login-button {
  cursor: pointer;
  text-align: center;
  height: 40px;
  line-height: 40px;
  background: dodgerblue;
  color: #fff;
  border-radius: 5px;
}
@keyframes login-small {
  0% {
    transform: translate(-50%, -50%) scale(1);
  }
  100% {
    transform: translate(-50%, -50%) scale(0.2);
  }
}
@keyframes rotating-plane {
  0% {
    transform: rotateX(0deg) rotateY(0);
  }
  50% {
    transform: rotateX(-180deg) rotateY(0);
  }
  100% {
    transform: rotateX(-180deg) rotateY(180deg);
  }
}
