:root {
  --bg: #ffffff;
  --text: #000000;
  --glow: #ffec80;
}

body {
  margin: 0;
  font-family: 'Roboto', sans-serif;
  background-color: var(--bg);
  color: var(--text);
  transition: background-color 0.4s, color 0.4s;
  padding: 1.5rem;
  box-sizing: border-box;
  overflow-x: hidden;
}

header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 2px solid var(--text);
  padding-bottom: 0.5rem;
  margin-bottom: 2rem;
  font-family: 'Oswald', sans-serif;
}

h1 {
  font-size: 2rem;
  letter-spacing: 1px;
}

.controls {
  display: flex;
  gap: 0.5rem;
}

button, nav {
  background: var(--bg);
  border: 1px solid var(--text);
  border-radius: 6px;
  color: var(--text);
  cursor: pointer;
  padding: 0.4rem 0.8rem;
  font-size: 1rem;
  transition: all 0.3s ease;
}

p {
  text-align: center;
  max-width: 600px;
  margin: 0 auto 3rem auto;
  font-size: 1.1rem;
  line-height: 1.6;
}

.pile {
  position: relative;
  width: 700px;
  height: 550px;
  margin: 0 auto;
  display: flex;
  justify-content: center;
  align-items: center;
  animation: fadeIn 1.8s ease-in-out;
}

.rock-card {
  position: absolute;
  transform: translate(var(--x), var(--y)) rotate(var(--r));
  transition: transform 0.5s ease;
  z-index: 1;
}

.rock-card img {
  width: 120px;
  border-radius: 8px;
  pointer-events: none;
  filter: brightness(1);
  transition: filter 0.3s ease, transform 0.3s ease;
}

a.rock-card:hover img {
  filter: drop-shadow(0 0 10px var(--glow)) drop-shadow(0 0 20px var(--glow));
}

body.night {
  background-color: #000;
  color: #fff;
}

body.night .rock-card img {
  filter: brightness(0.4);
}

.rock-card:hover {
  z-index: 5;
  transform: translate(var(--x), var(--y)) rotate(0deg) scale(1.05);
}

.featured-rock {
  display: block;
  margin: 0 auto;
  max-width: 100%;
  height: auto;
}

@keyframes fadeIn {
  from { opacity: 0; transform: scale(0.95); }
  to { opacity: 1; transform: scale(1); }
}