CSS/box-shadow

CSS 
box-shadow: 水平方向　垂直方向　 ぼかし　広がり　色;
box-shadow: 5px 5px 5px 5px #aaa;
box-shadow: 0 10px 6px -6px #aaa;
box-shadow:1px 9px 23px -1px #aaa;
hover:box-shadow: 0 150px 0 0 rgba(0, 0, 0, 0.5) inset;
hover:box-shadow: 0 0 0 10px rgba(0, 0, 0, 0.5) inset;
hover:box-shadow: 0 0 0 10px #9acc5f inset, 0 0 0 150px rgba(0, 0, 0, 0.5) inset;
hover:box-shadow: 300px 0 0 0 rgba(0, 0, 0, 0.25) inset, -300px 0 0 0 rgba(0, 0, 0, 0.25) inset;
hover:box-shadow: 0 80px 0 0 rgba(0, 0, 0, 0.25) inset, 0 -80px 0 0 rgba(0, 0, 0, 0.25) inset;
hover:box-shadow: 300px 0 0 0 rgba(0, 0, 0, 0.5) inset;
hover:box-shadow: -300px 0 0 0 rgba(0, 0, 0, 0.5) inset;
box-shadow: 3px 3px 6px -2px #555, 3px 3px 8px rgba(255,255,255,0.8) inset;