[css] transition-timing-fuction

transition: opacity 1s linear;
transition: width 3s ease-in-out;
transition: box-shadow 5s ease-in-out;
animation: @keyframes명 .5s ease-out

• linear : 속도 동일
• ease : (잠깐)느리게 - 상당히 빠르게 - 느리게
• ease-in : 느리게 - 빠르게
• ease-out : 빠르게 - 느리게
• ease-in-out : 느리게 - 빠르게 - 느리게