Voltage Drops - Xmas lights?

Hello, i just wanna start by saying i appreciate any help at all and am grateful for this forum! Also, the only electrical knowledge i have are that of self experimentation, no education.

So i have always been curious to how xmas lights were able to go so far, while providing the right amount of voltage and current to each light bulb.

I am trying to build something similar, using DC lithium ion 3.7-4.2v batteries.
I am building a dettachable solar system, so each globe has about 5-12 standard LEDs inside them, and a lithium ion battery, with a TP4056 charger.

Problem is, sending 5V through the wires, only the first globe would receive the full 5v,,, the next few would not receive enough voltage to the tp4056 charger.

I thought about sending 12v across, but using a step down module at each globe, but that just seems so bulky. Which is why i ask the question, how does the xmas lights do it... Or other appliances, you don't see a bulky piece before each light, so it's not a step down module.

I thought about using resistors, but that's different for each globe as the voltage goes lower and lower throughout the main wire leads.