写点CSS

自写+抄袭一个神秘动态背景
↓效果

/* Google Font */
@import url("https://fonts.googleapis.com/css2?family=Poppins:wght@300;400;600;700&display=swap");

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: "Poppins", sans-serif;
}

.container {
  width: 100%;
  height: 100vh;
  background: url("https://www.ncpsnetworks.com/static/rain.jpg") no-repeat;
  background-size: cover;
  background-position: center;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  background-color: #e493d0;
  background-image: 
      radial-gradient(closest-side, rgba(235, 105, 78, 1), rgba(235, 105, 78, 0)),
      radial-gradient(closest-side, rgba(243, 11, 164, 1), rgba(243, 11, 164, 0)),
      radial-gradient(closest-side, rgba(254, 234, 131, 1), rgba(254, 234, 131, 0)),
      radial-gradient(closest-side, rgba(170, 142, 245, 1), rgba(170, 142, 245, 0)),
      radial-gradient(closest-side, rgba(248, 192, 147, 1), rgba(248, 192, 147, 0));
  background-size: 
      130vmax 130vmax,
      80vmax 80vmax,
      90vmax 90vmax,
      110vmax 110vmax,
      90vmax 90vmax;
  background-position:
      -80vmax -80vmax,
      60vmax -30vmax,
      10vmax 10vmax,
      -30vmax -10vmax,
      50vmax 50vmax;
  background-repeat: no-repeat;
  animation: 10s movement linear infinite;
  display: flex;
      justify-content: center;
      align-items: center;
      height: 100vh;
      width: 100vw;
      flex-direction: column;
      font-size: calc(1em + 1vw);
      font-family: Arial, sans-serif;
}

.container .login-box {
  position: relative;
  width: 390px;
  height: 420px;
  background-color: transparent;
  border: 2px solid rgba(255, 255, 255, 0.5);
  border-radius: 40px;
  display: flex;
  justify-content: center;
  align-items: center;
  backdrop-filter: blur(15px);
}

.login-box h2 {
  font-size: 28px;
  color: #fff;
  text-align: center;
}

.login-box .input-box {
  position: relative;
  width: 310px;
  margin: 30px 0;
  border-bottom: 2px solid #fff;
}

.input-box input {
  width: 100%;
  height: 50px;
  background: transparent;
  border: none;
  outline: none;
  font-size: 16px;
  color: #fff;
  padding: 0 35px 0 5px;
}

.input-box input::placeholder {
  color: #f9f9f9;
}

.input-box .icon {
  position: absolute;
  right: 8px;
  color: #fff;
  font-size: 18px;
  line-height: 50px;
}

.login-box .remember-forget {
  margin: -15px 0 15px;
  font-size: 15px;
  color: #fff;
  display: flex;
  justify-content: space-between;
}

.remember-forget label input {
  margin-right: 3px;
}

.login-box button {
  width: 100%;
  height: 40px;
  background: #fff;
  border: none;
  outline: none;
  border-radius: 40px;
  cursor: pointer;
  font-size: 16px;
  color: #000;
  transition: all 0.3s ease;
}

.login-box button:hover {
  background: #1f73c9;
  /* #1f73c9 */
  color: #fff;
  box-shadow: 0px 10px 15px -3px rgba(31, 115, 201, 0.3), 0px 4px 6px -2px rgba(0, 0, 0, 0.05);
  transform: translateY(-2px);
}

.login-box button:active {
  background: #164e8a;
  box-shadow: 0px 5px 10px -3px rgba(0, 0, 0, 0.1);
  transform: translateY(px);
}

.login-box .register-link {
  font-size: 15px;
  color: #fff;
  text-align: center;
  margin: 20px 0 10px;
}

.remember-forget a,
.register-link a {
  color: #fff;
  text-decoration: none;
}

.remember-forget a:hover,
.register-link a:hover {
  text-decoration: underline;
}

/* Responsive Design */
@media (max-width: 460px) {
  .container .login-box {
    width: 350px;
  }

  .login-box .input-box {
    width: 290px;
  }
}

@media (max-width: 360px) {
  .container .login-box {
    width: 100%;
    height: 100vh;
    border: none;
  }
}

@keyframes movement {
  0%, 100% {
      background-size: 
      130vmax 130vmax,
      80vmax 80vmax,
      90vmax 90vmax,
      110vmax 110vmax,
      90vmax 90vmax;
      background-position:
      -80vmax -80vmax,
      60vmax -30vmax,
      10vmax 10vmax,
      -30vmax -10vmax,
      50vmax 50vmax;
  }
  25% {
      background-size: 
      100vmax 100vmax,
      90vmax 90vmax,
      100vmax 100vmax,
      90vmax 90vmax,
      60vmax 60vmax;
      background-position:
      -60vmax -90vmax,
      50vmax -40vmax,
      0vmax -20vmax,
      -40vmax -20vmax,
      40vmax 60vmax;
  }
  50% {
      background-size: 
      80vmax 80vmax,
      110vmax 110vmax,
      80vmax 80vmax,
      60vmax 60vmax,
      80vmax 80vmax;
      background-position:
      -50vmax -70vmax,
      40vmax -30vmax,
      10vmax 0vmax,
      20vmax 10vmax,
      30vmax 70vmax;
  }
  75% {
      background-size: 
      90vmax 90vmax,
      90vmax 90vmax,
      100vmax 100vmax,
      90vmax 90vmax,
      70vmax 70vmax;
      background-position:
      -50vmax -40vmax,
      50vmax -30vmax,
      20vmax 0vmax,
      -10vmax 10vmax,
      40vmax 60vmax;}
}