CSS :focus 의사 클래스: 포커스 대상

<label for="name">이름</label>
<input id="name" type="text">
<br>
<label for="occupation">직업</label>
<select id="occupation">
  <option>전문직</option>
  <option>사무직</option>
  <option>서비스/영업/판매직</option>
  <option>생산/기술직/노무직</option>
  <option>교사/강사</option>
  <option>학생</option>
  <option>프리랜서</option>
  <option>무직</option>
  <option>기타</option>
</select>
<br>
<button type="button">확인</button>

input:focus {
  background: lightblue;
  outline: 2px solid dodgerblue;
}

select:focus {
  background: khaki;
}

button:focus {
  outline: 2px dashed mediumseagreen;
}

:focus {
  /* ... */
}

:focus {
  outline: none;
}