Created a simple Earth simulation-like with a message with CSS only.

#frontendchallenge #css

This is a submission for Frontend Challenge v24.04.17, CSS Art: Earth Day.

Hey there!
I built a Earth showing it's transition from being natural to dreadfulness with CSS animations.
This simply highlights the immediate need of protecting the earth before it's gone.

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Earth Day - Protect Our Planet</title>
  <style>
body {
  margin: 0;
  padding: 0;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  background: linear-gradient(to bottom, #e0e0e0 0%, #ececec 30%, #f0f0f0 60%);
}

.earth {
  width: 280px;
  height: 280px;
  border-radius: 50%;
  position: relative; /* Make Earth the reference point for message positioning */
  background: conic-gradient(#2c9bff 0%, #43a047 60%); /* Healthy Earth colors */
  box-shadow: inset 4px 4px 10px rgba(0, 0, 0, 0.2), 0 0 15px rgba(255, 255, 255, 0.4);
  animation: earth-state 10s linear infinite alternate;
}

@keyframes earth-state {
from {
    background: conic-gradient(#2c9bff 0%, #43a047 60%); /* Healthy Earth colors (0%) */
  }
  /* No intermediate keyframes needed as messages control visibility */
  to {
    background: conic-gradient(#333 0%, #555 60%); /* Deteriorated Earth colors (100%) */
  }
}



.message {
  position: absolute;
  transform: translateX(-50%); /* Center horizontally */
  white-space: nowrap;
  font-size: 20px;
  color: #fff;
  text-shadow: 0 0 5px #000;
  opacity: 0; /* Initially invisible */
}

.message.before {
  top: calc(50% - 60px); /* Position above Earth with offset */
  transform: translateX(-50%); /* Center horizontally */
  animation: message-fade-before 10s linear infinite alternate; /* Separate fade animation */
}

.message.after {
  top: calc(50% + 60px); /* Position below Earth with offset */
  transform: translateX(-50%); /* Center horizontally */
  animation: message-fade-after 10s linear infinite alternate; /* Separate fade animation */
}

@keyframes message-fade-before {
  /* Fade out slightly before the full color transition of Earth (around 70%) */
  0% {
    opacity: 1; /* Visible when Earth is healthy (before message) */
  }
  8 0% {
    opacity: 0; /* Fade out before Earth deteriorates */
  }
  100% {
    opacity: 0; /* Remain invisible during deteriorated state */
  }
}

@keyframes message-fade-after {
  /* Fade in when Earth is fully deteriorated (100%) */
  0% {
    opacity: 0; /* Remain invisible until fully deteriorated */
  }
  100% {
    opacity: 1; /* Visible only at 100% (deteriorated state) */
  }
}
  </style>
</head>
<body>
  <div class="earth"></div>
 <div class="message before">Protect Our Planet Before...</div>
  <div class="message after">It's Gone...</div>
</body>
</html>

This was pretty challenging to implement the idea of Earth transition from a natural state(blue & green) to it's deteriorated and dreadful state(gloomy grey)using pure CSS.
I mustered myself on completing this challenge and finished with what I could.
The takeaway from this was learning about keyframes in CSS and not relying on Javascript to enhance the visual outlook of the prototype.
Thanks for this challenge DEV team!
I hope everybody who participated had learnt something regardless of how you feel about it.