title: ASP.NET I can't write into HTML Input
body: <p>I have a simple login page, which I wanted to beautify with some snow in the background. However this makes it unable for me to input anything into the input box, even if z-index is set to 100:</p>
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-css lang-css prettyprint-override"><code>/* CSS (Login) : */
  
  .login-page {
    width: 360px;
    padding: 8% 0 0;
    margin: auto;
  }
  
  .form {
    position: relative;
    z-index: 1;
    background: #FFFFFF;
    max-width: 360px;
    margin: 0 auto 100px;
    padding: 45px;
    text-align: center;
    box-shadow: 0 0 20px 0 rgba(0, 0, 0, 0.2), 0 5px 5px 0 rgba(0, 0, 0, 0.24);
  }
  
  .form input {
    font-family: "Roboto", sans-serif;
    outline: 0;
    background: #f2f2f2;
    width: 100%;
    border: 0;
    margin: 0 0 15px;
    padding: 15px;
    box-sizing: border-box;
    font-size: 14px;
  }
  
  .form button {
    font-family: "Roboto", sans-serif;
    text-transform: uppercase;
    outline: 0;
    background: #4CAF50;
    width: 100%;
    border: 0;
    padding: 15px;
    color: #FFFFFF;
    font-size: 14px;
    -webkit-transition: all 0.3 ease;
    transition: all 0.3 ease;
    cursor: pointer;
  }
  
  .form button:hover,
  .form button:active,
  .form button:focus {
    background: #43A047;
  }
  
  .form .message {
    margin: 15px 0 0;
    color: #b3b3b3;
    font-size: 12px;
  }
  
  .form .message a {
    color: #4CAF50;
    text-decoration: none;
  }
  
  .form .register-form {
    display: none;
  }
  
  .container {
    position: relative;
    z-index: 1;
    max-width: 300px;
    margin: 0 auto;
  }
  
  .container:before,
  .container:after {
    content: "";
    display: block;
    clear: both;
  }
  
  .container .info {
    margin: 50px auto;
    text-align: center;
  }
  
  .container .info h1 {
    margin: 0 0 15px;
    padding: 0;
    font-size: 36px;
    font-weight: 300;
    color: #1a1a1a;
  }
  
  .container .info span {
    color: #4d4d4d;
    font-size: 12px;
  }
  
  .container .info span a {
    color: #000000;
    text-decoration: none;
  }
  
  .container .info span .fa {
    color: #EF3B3A;
  }
  
  body {
    background: #76b852;
    /* fallback for old browsers */
    background: -webkit-linear-gradient(right, #76b852, /*#8DC26F*/
    #333);
    background: -moz-linear-gradient(right, #76b852, /*#8DC26F*/
    #333);
    background: -o-linear-gradient(right, #76b852, /*#8DC26F*/
    #333);
    background: linear-gradient(to left, #76b852, /*#8DC26F*/
    #333);
    font-family: "Roboto", sans-serif;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
  }
  
  /* CSS (Snow) : */
  
  .background {
    color: transparent;
    position: absolute;
    top: 0;
    left: 0;
    z-index: -2;
  }
  
  .winter-is-coming,
  .snow {
    z-index: -1;
    pointer-events: none;
  }
  
  .winter-is-coming {
    overflow: hidden;
    position: fixed;
    top: 0;
    height: 100%;
    width: 100%;
    max-width: initial;
    background: #333;
  }
  
  .snow {
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    animation: falling linear infinite both;
    transform: translate3D(0, -100%, 0);
  }
  
  .snow--near {
    animation-duration: 10s;
    background-image: url('https://dl6rt3mwcjzxg.cloudfront.net/assets/snow/snow-    large-075d267ecbc42e3564c8ed43516dd557.png');
    background-size: contain;
  }
  
  .snow--near+.snow--alt {
    animation-delay: 5s;
  }
  
  .snow--mid {
    animation-duration: 20s;
    background-image: url('https://dl6rt3mwcjzxg.cloudfront.net/assets/snow/snow-    medium-0b8a5e0732315b68e1f54185be7a1ad9.png');
    background-size: contain;
  }
  
  .snow--mid+.snow--alt {
    animation-delay: 10s;
  }
  
  .snow--far {
    animation-duration: 30s;
    background-image: url('https://dl6rt3mwcjzxg.cloudfront.net/assets/snow/snow-    small-1ecd03b1fce08c24e064ff8c0a72c519.png');
    background-size: contain;
  }
  
  .snow--far+.snow--alt {
    animation-delay: 15s;
  }
  
  @keyframes falling {
    0% {
      transform: translate3D(-7.5%, -100%, 0);
    }
    100% {
      transform: translate3D(7.5%, 100%, 0);
    }
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;div class="winter-is-coming login-page"&gt;
    &lt;div class="snow snow--near"&gt;&lt;/div&gt;
    &lt;div class="snow snow--near snow--alt"&gt;&lt;/div&gt;
  
    &lt;div class="snow snow--mid"&gt;&lt;/div&gt;
    &lt;div class="snow snow--mid snow--alt"&gt;&lt;/div&gt;
  
    &lt;div class="snow snow--far"&gt;&lt;/div&gt;
    &lt;div class="snow snow--far snow--alt"&gt;&lt;/div&gt;
    &lt;div class="form" style="z-index:100;"&gt;
      &lt;form class="login-form"&gt;
        &lt;h1&gt;Login&lt;/h1&gt;
        &lt;input type="text" placeholder="Username" id="usernameBox" /&gt;
        &lt;input type="password" placeholder="Password" id="passwordBox" /&gt;
        &lt;button runat="server" onclick="loginClicked"&gt;login&lt;/button&gt;
      &lt;/form&gt;
    &lt;/div&gt;
  &lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>
  <p>I know that the error lays in Snow.css, because if I don't use it, I can use my login normally, but I can't find anything wrong within the file</p>