lab.css

:root {
  --white: #f0f0f0;
  --light-grey: #e4e4e4;
  --black: #111111;
  --dark-grey: #272727;
  --bg: var(--white);
  --txt: var(--black);
  --dark-opacity: 0;
  --light-opacity: 1;
}
/* ^Required for Dark Mode Toggle code^ */

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}


/** Dark/Light Toggle code start: **/

.content {
  background-color: var(--bg);
  color: var(--txt);
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  transition: background 0.3s ease 0s;
}

.toggle {
  bottom: 25vh;
  right: 10vw;
}

.checkbox {
  display: none;
}

.label {
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: relative;
  background: var(--txt);
  border-radius: 5rem;
  padding: 0.5rem;
  height: 2.5rem;
  width: 5rem;
  font-size: 1.5rem;
  transition: background 0.5s ease 0s;
  cursor: pointer;
  z-index: 1;
}

.label .ball {
  position: absolute;
  background-color: var(--bg);
  border-radius: 50%;
  top: 0.25rem;
  left: 0.25rem;
  height: 2rem;
  width: 2rem;
  transform: translateX(0);
  transition: transform 0.3s ease, background-color 0.5s ease;
}

.checkbox:checked+.content .label .ball {
  transform: translateX(2.5rem);
}

.checkbox:checked+.content {
  --bg: var(--black);
  --txt: var(--white);
  --dark-opacity: 1;
  --light-opacity: 0;
}

/** Dark/Light Toggle code end. **/


/* Main part start: */

.body {
  background: var(--bg);
  color: var(--txt);
  font-family: "Segoe UI Variable Display", Verdana, sans-serif;
}

.title {
  font-size: 1.5rem;
  font-weight: 400;
}