styles.css

h1 {
  color: #369;
  font-family: Arial, Helvetica, sans-serif;
  font-size: 250%;
}
body {
  margin: 2em;
}

body {
  background: #369;
}

h1, h2, h3 {
  margin: 40px auto;
  color: #fff;
  letter-spacing: 3px;
}

h1 {font: 22px Helvetica;   text-align: center;}
h2 {font: 20px Helvetica;}
h3 {font: 16px Helvetica;   text-align: center;}

form {
  display: table;
  margin: 40px auto;
}

form label {
    position: relative;
    display: block;
}
form input {
  font: 18px Helvetica, Arial, sans-serif;
  box-sizing: border-box;
  display: block;
  border: none;
  padding: 20px;
  width: 300px;
  margin-bottom: 20px;
  font-size: 18px;
  outline: none;
  transition: all 0.2s ease-in-out;
} 
form input::placeholder {
  transition: all 0.2s ease-in-out;
  color: #999;
  font: 18px Helvetica, Arial, sans-serif;
}
  
form input:focus, form input.populated {
  padding-top: 28px;
  padding-bottom: 12px;
}
form input::placeholder {
  color: transparent;
}
    
form input + span {
  opacity: 1;
  top: 10px;
}

form span {
  color: #35dc9b;
  font: 13px Helvetica, Arial, sans-serif;
  position: absolute;
  top: 0px;
  left: 20px;
  opacity: 0;
  transition: all 0.2s ease-in-out;
}
  
input[type="submit"] {
  transition: all 0.2s ease-in-out;
  font: 18px Helvetica, Arial, sans-serif;
  border: none;
  background: #1aaf75;
  color: #fff;
  padding: 16px 40px;
  cursor: pointer;
} 
input[type="submit"]:hover {
  background: #109f67;
}

button {
  font-size: 14px;
  padding: 8px;
  cursor: pointer;
  color: white;
  background-color: #1aaf75;
  border: 2px solid #1aaf75;
}

button[disabled] {
  background-color: gray;
  border: 2px solid gray;
}
section {
  padding: 0 0 15px 15px;
}

/****************     Form     ****************/
.ng-valid[required] {
  border-left: 5px solid #42A948; /* green */
}

.ng-invalid {
  border-left: 5px solid #a94442; /* red */
}