/// ========== IGNORE ========== ///
#include "FastLED.h"
#include <SPI.h>
#define NUM_LEDS    100
CRGB leds[NUM_LEDS]; void setup() { FastLED.addLeds<WS2811, 5, GRB>(leds, NUM_LEDS); }
/// ========== IGNORE ========== ///
int offset = 0;

void loop() {
  FastLED.clear(); // Clear all lights

  int sinOffset = sin((double)offset / 25) * 50;

  for (int i = sinOffset; i < NUM_LEDS - sinOffset; i++) {
    double hue = (double)i / NUM_LEDS * 255;
    if (i > (NUM_LEDS - sinOffset) / 2) {
      leds[i] = CHSV(255 - int(hue), 255, 255);
    } else {
      leds[i] = CHSV(int(hue), 255, 255);
    }
  }
  delay(10);
  offset ++;
  FastLED.show(); // Update strip lights
}