Flexible Sticky Footer with Flexbox

html, body {
  height: 100%;
  margin: 0;
}

body {
  display: flex;
  flex-direction: column; /* Stacks children vertically */
}

.main-content {
  flex: 1; /* This pushes the footer down to the bottom */
  padding: 20px;
}

.footer {
  padding: 20px;
  background-color: #333;
  color: white;
  text-align: center;
  flex-shrink: 0; /* Prevents footer from shrinking if content is too large */
}

How it works: This snippet creates a 'sticky footer' that always rests at the bottom of the viewport. By setting `html` and `body` to `height: 100%` and `body` to `display: flex` with `flex-direction: column`, the `.main-content` element can be given `flex: 1`. This property allows `main-content` to grow and consume all available vertical space, effectively pushing the `.footer` element to the very bottom of the page, regardless of how much content is present.