diff --git a/白板/index.html b/白板/index.html
new file mode 100644
index 0000000..2340823
--- /dev/null
+++ b/白板/index.html
@@ -0,0 +1 @@
+<canvas id=v><script>d=document,d.body.style.margin=0,P="onpointer",c=v.getContext`2d`,v.width=innerWidth,v.height=innerHeight,c.lineWidth=2,f=0,d[P+"down"]=e=>{f=e.pointerId+1;e.preventDefault();c.beginPath();c.moveTo(e.x,e.y)};d[P+"move"]=e=>{f==e.pointerId+1&&c.lineTo(e.x,e.y);c.stroke()},d[P+"up"]=_=>f=0</script></canvas>