* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
}

html,
body {
  width: 100%;
  height: 100%;
  color: #fff;
  background: #0b0c2d;
  overflow-x: hidden;
}

canvas#space {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  pointer-events: none;
}

header {
  text-align: center;
  margin-top: 60px;
  z-index: 1;
  position: relative;
}

h1 {
  font-size: 3rem;
  color: #ff4c4c;
  text-shadow: 0 0 15px rgba(255, 0, 0, 0.6);
}

.mars {
  width: 260px;
  height: 260px;
  margin: 50px auto;
  border-radius: 50%;
  position: relative;
  cursor: pointer;
  animation: float 8s ease-in-out infinite;
  background: radial-gradient(
    circle at 30% 30%,
    #d94c1a 0%,
    #9b2a16 45%,
    #6e1412 75%,
    #2e0606 100%
  );
  box-shadow: inset -60px -40px 80px rgba(0, 0, 0, 0.6),
    inset 30px 20px 40px rgba(255, 120, 60, 0.15),
    0 0 50px rgba(220, 70, 30, 0.5), 0 0 100px rgba(255, 60, 20, 0.45);
}

.mars::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: 50%;
  background: radial-gradient(
    circle at 75% 75%,
    rgba(0, 0, 0, 0.7),
    transparent 60%
  );
  mix-blend-mode: multiply;
}

.mars::before {
  content: "";
  position: absolute;
  inset: -8px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(255, 80, 30, 0.35), transparent 70%);
  filter: blur(8px);
  z-index: -1;
}

@keyframes float {
  0%,
  100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-15px);
  }
}

.mars:hover {
  transform: scale(1.04);
  box-shadow: inset -60px -40px 80px rgba(0, 0, 0, 0.6),
    inset 30px 20px 40px rgba(255, 120, 60, 0.15),
    0 0 70px rgba(255, 80, 40, 0.7), 0 0 130px rgba(255, 60, 20, 0.6);
}

nav {
  margin-top: 20px;
  text-align: center;
  z-index: 1;
  position: relative;
}

.nav-button {
  background-color: #ff4c4c;
  border: none;
  padding: 15px 30px;
  font-size: 1.2rem;
  color: #fff;
  border-radius: 10px;
  cursor: pointer;
  transition: 0.3s;
  text-decoration: none;
  display: block;
  max-width: 250px;
  width: 80%;
  margin: 15px auto;
}

.nav-button:hover {
  background-color: #ff1a1a;
  transform: scale(1.1);
}

input,
select {
  padding: 10px;
  font-size: 1rem;
  margin: 10px auto;
  border-radius: 6px;
  border: none;
  text-align: center;
  display: block;
  width: 200px;
  max-width: 80%;
}