* {
  box-sizing: border-box;
}

body {
  background: #F3F3F4;
  color: #333;
  padding: 20px;
}

form {
  width: 400px;
  margin: 0 auto 0;
}

.input-holder {
  position: relative;
  margin: 0 0 20px;
}

input,
textarea {
  border: 2px solid #ccc;
  border-radius: 4px;
  padding: 10px;
  width: 100%;
  resize: none;
  transition: .3s;
}
input:focus,
textarea:focus {
  border: 2px solid #999;
  outline: none;
}

textarea {
  min-height: 100px;
}

.message {
  position: absolute;
  z-index: 9;
  display: none;
  width: 100%;
  padding: 10px;
  margin-top: 10px;
  background: #D9585C;
  color: #fff;
  text-align: center;
}
.message:after {
  content: '';
  position: absolute;
  top: -10px;
  left: 50%;
  display: block;
  margin-left: -10px;
  border: solid;
  border-color: #D9585C transparent #D9585C;
  border-width: 0 10px 10px;
}

.is-valid {
  border-color: #AAD661 !important;
  transition: 0;
}

.not-valid {
  border-color: #D7595F;
  transition: 0;
}
.not-valid + .message {
  display: block !important;
}

.submit {
  display: block;
  width: 100%;
  padding: 10px;
  border: 2px solid #ccc;
  border-radius: 4px;
  background: transparent;
  color: #ccc;
  transition: .3s;
}
.submit:hover {
  color: #AAD661;
  border-color: #AAD661;
}