:root {
  --input-color: #99A3BA;
  --input-border: #CDD9ED;
  --input-background: #fff;
  --input-placeholder: #CBD1DC;
  --input-border-focus: #275EFE;
  --group-color: var(--input-color);
  --group-border: var(--input-border);
  --group-background: #EEF4FF;
  --group-color-focus: #fff;
  --group-border-focus: var(--input-border-focus);
  --group-background-focus: #678EFE;
}

.form-field {
  display: block;
  width: 100%;
  padding: 8px 16px;
  line-height: 25px;
  font-size: 14px;
  font-weight: 500;
  font-family: inherit;
  border-radius: 6px;
  -webkit-appearance: none;
  color: var(--input-color);
  border: 1px solid var(--input-border);
  background: var(--input-background);
  transition: border 0.3s ease;
}
.form-field::-moz-placeholder {
  color: var(--input-placeholder);
}
.form-field:-ms-input-placeholder {
  color: var(--input-placeholder);
}
.form-field::placeholder {
  color: var(--input-placeholder);
}
.form-field:focus {
  outline: none;
  border-color: var(--input-border-focus);
}

.form-group {
  position: relative;
  display: flex;
  width: 100%;
  margin: 10px;
}
.form-group > span,
.form-group .form-field {
  white-space: nowrap;
  display: block;
}
.form-group > span:not(:first-child):not(:last-child),
.form-group .form-field:not(:first-child):not(:last-child) {
  border-radius: 0;
}
.form-group > span:first-child,
.form-group .form-field:first-child {
  border-radius: 6px 0 0 6px;
}
.form-group > span:last-child,
.form-group .form-field:last-child {
  border-radius: 0 6px 6px 0;
}
.form-group > span:not(:first-child),
.form-group .form-field:not(:first-child) {
  margin-left: -1px;
}
.form-group .form-field {
  position: relative;
  z-index: 1;
  flex: 1 1 auto;
  width: 1%;
  margin-top: 0;
  margin-bottom: 0;
}
.form-group > span {
  text-align: center;
  padding: 8px 12px;
  font-size: 14px;
  line-height: 25px;
  color: var(--group-color);
  background: var(--group-background);
  border: 1px solid var(--group-border);
  transition: background 0.3s ease, border 0.3s ease, color 0.3s ease;
}
.form-group:focus-within > span {
  color: var(--group-color-focus);
  background: var(--group-background-focus);
  border-color: var(--group-border-focus);
}