💎flex

■ 개념

.con {
       background: #FFEFD5;
       height: 100vh;
       /* flex로 보여줘 */
       display: flex;
      }

■ flex-direction

1.1 flex-direction: row;

1.2 flex-direction: row;

2.1 flex-direction: column;

2.2 flex-direction: column-reverse;