input and float label with pattern

Question

I have a problem with an input tag and label its float . Everything works properly read , but when I insert a pattern in the input if this pattern is not satisfied with the effect float is not realized , and the text input overlaps with the label . I hope I was clear , sorry for my english.

this is css

.card .input-container {
  position: relative;
  margin: 0 60px 50px;
}
.card .input-container input {
  outline: none;
  z-index: 1;
  position: relative;
  background: none;
  width: 100%;
  height: 60px;
  border: 0;
  color: #212121;
  font-size: 24px;
  font-weight: 400;
}
.card .input-container input:focus ~ label {
  color: #9d9d9d;
  -webkit-transform: translate(-12%, -50%) scale(0.75);
  transform: translate(-12%, -50%) scale(0.75);
}
.card .input-container input:focus ~ .bar:before, .card .input-container input:focus ~ .bar:after {
  width: 50%;
}
.card .input-container input:valid ~ label {
  color: #9d9d9d;
  -webkit-transform: translate(-12%, -50%) scale(0.75);
  transform: translate(-12%, -50%) scale(0.75);
}
.card .input-container label {
  position: absolute;
  top: 0;
  left: 0;
  color: #757575;
  font-size: 24px;
  font-weight: 300;
  line-height: 60px;
  -webkit-transition: 0.2s ease;
  transition: 0.2s ease;
}
.card .input-container .bar {
  position: absolute;
  left: 0;
  bottom: 0;
  background: #757575;
  width: 100%;
  height: 1px;
}
.card .input-container .bar:before, .card .input-container .bar:after {
  content: '';
  position: absolute;
  background: #ed2553;
  width: 0;
  height: 2px;
  -webkit-transition: .2s ease;
  transition: .2s ease;
}
.card .input-container .bar:before {
  left: 50%;
}
.card .input-container .bar:after {
  right: 50%;
}

<div class="card">
  <h1 class="title">Login</h1>
  <form>
    <div class="input-container">
      <input type="text" id="Username" required="required" pattern=".{3,}"  title="3 characters minimum" />
      <label for="Username">Username</label>
      <div class="bar"></div>
    </div>
  </form>
</div>

Answer 1

I would suggest you this, if you want to keep the animation intact. Checking the validity of the input, should be done using JavaScript and make the input, just be required. Remove the pattern altogether and give something like this:

.card .input-container {
  position: relative;
  margin: 0 60px 50px;
}
.card .input-container input {
  outline: none;
  z-index: 1;
  position: relative;
  background: none;
  width: 100%;
  height: 60px;
  border: 0;
  color: #212121;
  font-size: 24px;
  font-weight: 400;
}
.card .input-container input:focus ~ label {
  color: #9d9d9d;
  -webkit-transform: translate(-12%, -50%) scale(0.75);
  transform: translate(-12%, -50%) scale(0.75);
}
.card .input-container input:focus ~ .bar:before, .card .input-container input:focus ~ .bar:after {
  width: 50%;
}
.card .input-container input:valid ~ label {
  color: #9d9d9d;
  -webkit-transform: translate(-12%, -50%) scale(0.75);
  transform: translate(-12%, -50%) scale(0.75);
}
.card .input-container label {
  position: absolute;
  top: 0;
  left: 0;
  color: #757575;
  font-size: 24px;
  font-weight: 300;
  line-height: 60px;
  -webkit-transition: 0.2s ease;
  transition: 0.2s ease;
}
.card .input-container .bar {
  position: absolute;
  left: 0;
  bottom: 0;
  background: #757575;
  width: 100%;
  height: 1px;
}
.card .input-container .bar:before, .card .input-container .bar:after {
  content: '';
  position: absolute;
  background: #ed2553;
  width: 0;
  height: 2px;
  -webkit-transition: .2s ease;
  transition: .2s ease;
}
.card .input-container .bar:before {
  left: 50%;
}
.card .input-container .bar:after {
  right: 50%;
}

<div class="card">
  <h1 class="title">Login</h1>
  <form>
    <div class="input-container">
      <input type="text" id="Username" required="required"  title="3 characters minimum" />
      <label for="Username">Username</label>
      <div class="bar"></div>
    </div>
  </form>
</div>

Or you can make the animation happen by adding a new class to the input using JavaScript / jQuery. A pure CSS solution for having both may not be possible. I said may not, because, I cannot think of one. Let's see if someone else comes up with a solution.

---

Alternate solution using jQuery:

$(function () {
  $("input").keyup(function () {
    if ($(this).val().trim().length > 0)
      $(this).addClass("non-empty");
    else
      $(this).removeClass("non-empty");
  });
});

.card .input-container {
  position: relative;
  margin: 0 60px 50px;
}
.card .input-container input {
  outline: none;
  z-index: 1;
  position: relative;
  background: none;
  width: 100%;
  height: 60px;
  border: 0;
  color: #212121;
  font-size: 24px;
  font-weight: 400;
}
.card .input-container input:focus ~ label {
  color: #9d9d9d;
  -webkit-transform: translate(-12%, -50%) scale(0.75);
  transform: translate(-12%, -50%) scale(0.75);
}
.card .input-container input:focus ~ .bar:before, .card .input-container input:focus ~ .bar:after {
  width: 50%;
}
.card .input-container input.non-empty ~ label {
  color: #9d9d9d;
  -webkit-transform: translate(-12%, -50%) scale(0.75);
  transform: translate(-12%, -50%) scale(0.75);
}
.card .input-container label {
  position: absolute;
  top: 0;
  left: 0;
  color: #757575;
  font-size: 24px;
  font-weight: 300;
  line-height: 60px;
  -webkit-transition: 0.2s ease;
  transition: 0.2s ease;
}
.card .input-container .bar {
  position: absolute;
  left: 0;
  bottom: 0;
  background: #757575;
  width: 100%;
  height: 1px;
}
.card .input-container .bar:before, .card .input-container .bar:after {
  content: '';
  position: absolute;
  background: #ed2553;
  width: 0;
  height: 2px;
  -webkit-transition: .2s ease;
  transition: .2s ease;
}
.card .input-container .bar:before {
  left: 50%;
}
.card .input-container .bar:after {
  right: 50%;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<div class="card">
  <h1 class="title">Login</h1>
  <form>
    <div class="input-container">
      <input type="text" id="Username" required="required" pattern=".{3,}"  title="3 characters minimum" />
      <label for="Username">Username</label>
      <div class="bar"></div>
    </div>
  </form>
</div>