<!--

1. Intro animation duration stagger
2. Mouse Position Tracking with CSS variables
3. Text Outline Reveal on Hover

-->

<div id="app">
  <nav class="main-nav" style="--total: 4">
    <a href="#" class="image-hover" style="--i: 0">
      <span class="title" data-title="Keyframers">Keyframers</span>
      <img src="https://images.unsplash.com/photo-1595263541702-64a36a9b1129?ixlib=rb-1.2.1&q=80&fm=jpg&crop=entropy&cs=tinysrgb&w=750&h=1000&fit=crop&ixid=eyJhcHBfaWQiOjE0NTg5fQ" alt="">
    </a>
    <a href="#" class="image-hover" style="--i: 1">
      <span class="title" data-title="Animation Amigos">Animation Amigos</span>
      <img src="https://images.unsplash.com/photo-1594977887411-f2ba50a01b0c?ixlib=rb-1.2.1&q=80&fm=jpg&crop=entropy&cs=tinysrgb&w=750&h=1000&fit=crop&ixid=eyJhcHBfaWQiOjE0NTg5fQ" alt="">
    </a>
    <a href="#" class="image-hover" style="--i: 2">
      <span class="title" data-title="CSS Tutorials">CSS Tutorials</span>
      <img src="https://images.unsplash.com/photo-1595639395288-46fba44df7c8?ixlib=rb-1.2.1&q=80&fm=jpg&crop=entropy&cs=tinysrgb&w=750&h=1000&fit=crop&ixid=eyJhcHBfaWQiOjE0NTg5fQ" alt="">
    </a>
    <a href="#" class="image-hover" style="--i: 3">
      <span class="title" data-title="JavaScript Bits">JavaScript Bits</span>
      <img src="https://images.unsplash.com/photo-1596413502478-3eeb71b2df32?ixlib=rb-1.2.1&q=80&fm=jpg&crop=entropy&cs=tinysrgb&w=750&h=1000&fit=crop&ixid=eyJhcHBfaWQiOjE0NTg5fQ" alt="">
    </a>
    <a href="#" class="image-hover" style="--i: 4">
      <span class="title" data-title="Boolean Buddies">Boolean Buddies</span>
      <img src="https://images.unsplash.com/photo-1568829198167-914b4194bdac?ixlib=rb-1.2.1&q=80&fm=jpg&crop=entropy&cs=tinysrgb&w=750&h=1000&fit=crop&ixid=eyJhcHBfaWQiOjE0NTg5fQ" alt="">
    </a>
  </nav>
</div>

<a href="https://youtu.be/EkKNosvVijM" target="_blank" data-keyframers-credit style="color: #FFF"></a>
<script src="https://codepen.io/shshaw/pen/QmZYMG.js"></script>

@import url("https://fonts.googleapis.com/css2?family=Roboto:wght@900&display=swap");

*,
*::before,
*::after {
  box-sizing: border-box;
  position: relative;
}

html,
body,
#app {
  height: 100%;
  width: 100%;
  margin: 0;
  padding: 0;
}

.main-nav {
  display: flex;
  flex-direction: column;
  justify-content: center;
  height: 100vh;
  padding: 3vh 1vw;
}

html {
  background: #060706;
  color: #fff;
  overflow: hidden;
  --easing: cubic-bezier(0.5, 0.5, 0.2, 1);
}

.image-hover {
  display: block;
  color: white;
  text-decoration: none;
  text-align: center;
  padding: 2vh 0;
  transform-origin: top left;
  animation: skwoop 0.7s var(--easing) backwards;
  animation-duration: calc(0.6s + (var(--i) * 0.1s));
  animation-delay: calc((var(--i) * 50ms));
  cursor: pointer;

  @keyframes skwoop {
    from {
      opacity: 0;
      transform: translateY(5vh) skewY(5deg);
    }
  }

  .title {
    font-family: "Roboto";
    font-weight: 900;
    font-size: 9vh;
    letter-spacing: 0.05ch;

    &::after {
      content: attr(data-title);
      position: absolute;
      top: 0;
      left: 0;
      z-index: 5;
      color: transparent;
      -webkit-text-stroke: 2px #fff;
      //-webkit-text-stroke: 2px red;
    }
  }

  > img {
    // display: none;
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    max-width: 40%;
    max-height: 60vh;
    pointer-events: none;
    z-index: 2;
    visibility: hidden;
    opacity: 0;
    transition: opacity 0.2s linear, visibility 0s linear 0.2s;
  }

  &:hover,
  &:focus {
    z-index: 10;
    .title::after {
      display: block;
    }
    > img {
      transition-delay: 0s;
      visibility: visible;
      opacity: 1;
    }
  }
}

.image-hover > img {
  --x-px: calc(var(--x) * 1px);
  --y-px: calc(var(--y) * 1px);
  top: 0;
  left: 0;
  transform: translate(var(--x-px), var(--y-px)) translate(-50%, -50%);
}

console.clear();
const elApp = document.querySelector("#app");

// What we need...
// Mouse position
// Currently hovered item

document.body.addEventListener("mousemove", (event) => {
  console.log({
    x: event.clientX,
    y: event.clientY
  });

  elApp.style.setProperty("--x", event.clientX);
  elApp.style.setProperty("--y", event.clientY);
});

// Replay animation by hiding & showing the element again
let el = document.body;
el.addEventListener("click", function (e) {
  el.hidden = true;
  requestAnimationFrame(() => {
    el.hidden = false;
  });
});