index.js

function darkMode() {
	jQuery("body").addClass("night").removeClass("day");
	jQuery("h1.gallery-head").addClass("night").removeClass("day");
	jQuery("p.lead").addClass("night").removeClass("day");
	document.documentElement.classList.add("dark");
}

function lightMode() {
	jQuery("body").addClass("day").removeClass("night");
	jQuery("h1.gallery-head").addClass("day").removeClass("night");
	jQuery("p.lead").addClass("day").removeClass("night");
	document.documentElement.classList.remove("dark");
}

$("#color-switch").on("change", function (e) {
	if (this.checked) {
		darkMode();
	} else {
		lightMode();
	}
});

const totop = document.querySelector(".backToTop");

window.addEventListener("scroll", () =>{
	if(window.pageYOffset > 100){
		totop.classList.add("active");
	} else{
		totop.classList.remove("active");
	}	
});

const setNormalView = (isNormalView) => {
	if (isNormalView) {
		document.querySelector('#normal-view').classList.add('selected');
      	document.querySelector('#compact-view').classList.remove('selected');

		document.querySelectorAll(".card-body").forEach((cardBody) => {
			cardBody.classList.remove("hidden");
		});

		document.querySelectorAll(".row>div").forEach((ele) => {
			ele.classList.replace("col-lg-2", "col-lg-4");
		});
	} else {
		document.querySelector('#compact-view').classList.add('selected');
      	document.querySelector('#normal-view').classList.remove('selected');

		document.querySelectorAll(".card-body").forEach((cardBody) => {
			cardBody.classList.add("hidden");
		});

		document.querySelectorAll(".row>div").forEach((ele) => {
			ele.classList.replace("col-lg-4", "col-lg-2");
		});
	}
};

setNormalView(true); // By default normal view is enabled.

document.querySelector('#normal-view').addEventListener('mousedown', () => {
	setNormalView(true);
});

document.querySelector('#compact-view').addEventListener('mousedown', () => {
	setNormalView(false);
});

  const fixBrokenImages = () => {
      const fallbackURL = 'images/fallback_image.png'
      const img = document.getElementsByTagName('img');
      for (let i = 0; i < img.length; i++) {
          let t = img[i];
          if (t.naturalWidth === 0) {
              t.src = fallbackURL;
          }
      }
  };
  
  window.onload = fixBrokenImages;