How to make this with CSS only 👇
1 / 8
First, you need an SVG that has TWO parts:
- Line
- Arrow
For drawing such curves you can use any vector editor. I used @sketch.
Tutorial on how to do this: sketch.com/docs/vector-ed…
Arrow is a simple triangle. 
2 / 8
Next, after you exported SVG, you can go to jakearchibald.github.io/svgomg/ in order to remove clutter from the SVG.
Btw, this is a nice hint: you can significantly reduce the size of SVG by using this awesome tool from @jaffathecake
3 / 8
Now you have something similar to this.
1.  Add classes to the line (path in my example) and triangle
2.  Add fill-opacity="0" for triangle
In CSS the only thing you need so far is:
.path {
   stroke-dasharray: 8;
}
That makes the line dashed. 
4 / 8
Now, the trickest part. 
In order to have an animated dashed line, you need to duplicate (!) the line path and make it a mask. 
Check the code below.
Now we have:
1.  Mask
2.  Line
3.  Triangle 
5 / 8
The actual animation is done via changing the `stroke-dasharray` property.
Check it out: developer.mozilla.org/en-US/docs/Web…
But we will animate MASK, not the initial line path. 
6 / 8
After the animation completed, we need to show the arrow (triangle).
For this purpose, we will change the `fill-opaicty` from zero to 100%.
Pay attention to animation-fill-mode, without this the triangle will disappear after the first animation attempt. 
7 / 8
Now, a slight improvement can be done by changing the animation timing function from linear to something more aesthetical.
1.  Go here easings.net
2.  Select a proper timing function that you like
3.  Update the mask animation property 
8 / 8
The rest is making the background, adding the button, and all that boring stuff. 
Completed example with code: codepen.io/akcium/pen/GRr…
!! Don't forget to change the layout in Codepen, since I used position absolute
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