带自定义动画背景的HTML textarea无法选中或输入的问题

问题原因 #

你的.circles元素采用绝对定位，宽高设置为100%，完全覆盖了整个页面区域，包括.context里的textarea。这些动画元素会拦截所有鼠标交互事件，导致下方的textarea无法被选中和输入。

解决方案 #

有两种简单的修复方式：

方案1：提升表单区域的层级 #

给包含textarea的.context容器添加z-index属性，让它处于动画元素的上方：

.context {
    width: 100%;
    position: absolute;
    top:100px;
    z-index: 10; /* 新增：提升层级 */
}

方案2：让动画元素不拦截鼠标事件 #

给.circles容器添加pointer-events: none，使鼠标事件直接穿透到下方元素：

.circles{
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
    pointer-events: none; /* 新增：禁止拦截鼠标事件 */
}

完整代码示例 #

修改后的CSS #

@import url('https://fonts.googleapis.com/css?family=Exo:400,700');
*{
    margin: 0px;
    padding: 0px;
}
body{
    font-family: 'Exo', sans-serif;
}
.context {
    width: 100%;
    position: absolute;
    top:100px;
    z-index: 10; /* 新增 */
}
.context h1{
    text-align: center;
    color: #fff;
    font-size: 50px;
}
.area{
    background: #4e54c8;  
    background: -webkit-linear-gradient(to left, #8f94fb, #4e54c8);  
    width: 100%;
    height:100vh;      
}
.circles{
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
    pointer-events: none; /* 新增（二选一即可） */
}
.circles li{
    position: absolute;
    display: block;
    list-style: none;
    width: 20px;
    height: 20px;
    background: rgba(255, 255, 255, 0.2);
    animation: animate 25s linear infinite;
    bottom: -150px;    
}
.circles li:nth-child(1){
    left: 25%;
    width: 80px;
    height: 80px;
    animation-delay: 0s;
}
.circles li:nth-child(2){
    left: 10%;
    width: 20px;
    height: 20px;
    animation-delay: 2s;
    animation-duration: 12s;
}
.circles li:nth-child(3){
    left: 70%;
    width: 20px;
    height: 20px;
    animation-delay: 4s;
}
.circles li:nth-child(4){
    left: 40%;
    width: 60px;
    height: 60px;
    animation-delay: 0s;
    animation-duration: 18s;
}
.circles li:nth-child(5){
    left: 65%;
    width: 20px;
    height: 20px;
    animation-delay: 0s;
}
.circles li:nth-child(6){
    left: 75%;
    width: 110px;
    height: 110px;
    animation-delay: 3s;
}
.circles li:nth-child(7){
    left: 35%;
    width: 150px;
    height: 150px;
    animation-delay: 7s;
}
.circles li:nth-child(8){
    left: 50%;
    width: 25px;
    height: 25px;
    animation-delay: 15s;
    animation-duration: 45s;
}
.circles li:nth-child(9){
    left: 20%;
    width: 15px;
    height: 15px;
    animation-delay: 2s;
    animation-duration: 35s;
}
.circles li:nth-child(10){
    left: 85%;
    width: 150px;
    height: 150px;
    animation-delay: 0s;
    animation-duration: 11s;
}
@keyframes animate {
    0%{
        transform: translateY(0) rotate(0deg);
        opacity: 1;
        border-radius: 0;
    }
    100%{
        transform: translateY(-1000px) rotate(720deg);
        opacity: 0;
        border-radius: 50%;
    }
}

HTML（无需修改） #

<div class="area" >
       <div class="context">
        <h1>Title</h1>
        <textarea id="userName"> Enter user name</textarea><br>
        <textarea id="password"> Enter password</textarea>
        
    </div>
            <ul class="circles">
                     <li></li>
                    <li></li>
                    <li></li>
                    <li></li>
                    <li></li>
                    <li></li>
                    <li></li>
                    <li></li>
                    <li></li>
                    <li></li>
            </ul>
    </div>

内容的提问来源于stack exchange，提问作者Signor