No, you should not protect your designs. A design is useless without a client to pay for it. And clients do not pay for designs, they pay for websites. What low-rent wannabe freelancers do when they need free design ideas is do is they go to other bigger websites and copy the ideas.
They don’t bother with the rest of it. They’re just like, ok, they put the menu over here and the buttons down here and rounded this and this type of color scheme. Then they go and re-implement your design scheme in their chosen platform. The reason they do this is that it’s completely impractical to try to copy actual code. They may rip small snippets off your CSS but that’s about it.
Nothing you do to protect your IP could ever protect you from this.