<div class="radikalwp-in-float"><input type="text" placeholder=" " value=""><label>نام کامل شما<//label><//div>

.radikalwp-in-float { position: relative; width: 280px; font-family: inherit; }
.radikalwp-in-float input {
  width: 100%;
  padding: 15px 14px 7px;
  font-family: inherit;
  font-size: 14px;
  color: #1e293b;
  background: #fff;
  border: 1.5px solid #e2e8f0;
  border-radius: 11px;
  outline: none;
  transition: border-color .3s ease;
}
.radikalwp-in-float input:focus { border-color: #6366f1; box-shadow: 0 0 0 3px rgba(99, 102, 241, .12); }
.radikalwp-in-float label {
  position: absolute;
  top: 50%;
  right: 15px;
  transform: translateY(-50%);
  font-size: 13.5px;
  color: #94a3b8;
  pointer-events: none;
  transition: all .22s ease;
}
.radikalwp-in-float input:focus + label,
.radikalwp-in-float input:not(:placeholder-shown) + label {
  top: 0;
  font-size: 10.5px;
  font-weight: 700;
  color: #6366f1;
  background: #fff;
  padding: 1px 6px;
  border-radius: 4px;
}