酷炫表单，触感未来：HTML与CSS动画的创新应用！

<div class="form-container">
        <form class="form">
          <div class="form-group">
            <label for="email">邮箱</label>
            <input required="" name="email" id="email" type="text">
          </div>
          <div class="form-group">
            <label for="textarea">内容</label>
            <textarea required="" cols="50" rows="10" id="textarea" name="textarea">          </textarea>
          </div>
          <button type="submit" class="form-submit-btn">提交</button>
        </form>
      </div

body{background: #212121;}
        .form-container {
  width: 400px;
  background: linear-gradient(#212121, #212121) padding-box,
              linear-gradient(145deg, transparent 35%,#e81cff, #40c9ff) border-box;
  border: 2px solid transparent;
  padding: 32px 24px;
  font-size: 14px;
  font-family: inherit;
  color: white;
  display: flex;
  flex-direction: column;
  gap: 20px;
  box-sizing: border-box;
  border-radius: 16px;
  background-size: 200% 100%;
  animation: gradient 5s ease infinite;
}
@keyframes gradient {
  0% {
    background-position: 0% 50%;
  }
  50% {
    background-position: 100% 50%;
  }
  100% {
    background-position: 0% 50%;
  }
}
.form-container button:active {
  scale: 0.95;
}
.form-container .form {
  display: flex;
  flex-direction: column;
  gap: 20px;
}
.form-container .form-group {
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.form-container .form-group label {
  display: block;
  margin-bottom: 5px;
  color: #717171;
  font-weight: 600;
  font-size: 12px;
}
.form-container .form-group input {
 
  padding: 12px 16px;
  border-radius: 8px;
  color: #fff;
  font-family: inherit;
  background-color: transparent;
  border: 1px solid #414141;
}
.form-container .form-group textarea {
 
  padding: 12px 16px;
  border-radius: 8px;
  resize: none;
  color: #fff;
  height: 96px;
  border: 1px solid #414141;
  background-color: transparent;
  font-family: inherit;
}
.form-container .form-group input::placeholder {
  opacity: 0.5;
}
.form-container .form-group input:focus {
  outline: none;
  border-color: #e81cff;
}
.form-container .form-group textarea:focus {
  outline: none;
  border-color: #e81cff;
}
.form-container .form-submit-btn {
  display: flex;
  align-items: flex-start;
  justify-content: center;
  align-self: flex-start;
  font-family: inherit;
  color: #717171;
  font-weight: 600;
  width: 40%;
  background: #313131;
  border: 1px solid #414141;
  padding: 12px 16px;
  font-size: inherit;
  gap: 8px;
  margin-top: 8px;
  cursor: pointer;
  border-radius: 6px;
}
.form-container .form-submit-btn:hover {
  background-color: #fff;
  border-color: #fff;
}