css好看的边框

效果图：缝纫线

outline: 1px blue dashed;
outline-offset:-5px;

内圆角

outline: 1px blue  dashed;
 outline-offset:-5px;
 border-radius:10px;
 box-shadow:0 0 0 5px transparent;

信封

padding:5px;
border: 5px solid transparent;
background: linear-gradient(white,white) padding-box,repeating-linear-gradient(-45deg, red 0, red 12.5%, transparent 0, transparent 25%, #58a 0, #58a 37.5%, transparent 0, transparent 50%) 0/5em 5em;
			

滚动的蚂蚁线

border: 1px solid transparent;
animation:ants 12s linear infinite;
background: linear-gradient(white,white) padding-box,repeating-linear-gradient(-45deg, $theme-color 0, $theme-color 25%, white 0, white 50%) 0/.6em .6em;
@keyframes ants{100%{background-position:100%;}}