:root {
  /* Colors - Space Theme */
  --space-black: #050508;
  --space-dark: #0a0a12;
  --space-light: #f0f0f5;
  --accent-gold: #ffd700;
  --accent-blue: #4f92ff;
  --accent-red: #ff4d4d;
  
  /* Planet Specifics */
  --sun-glow: #ffcc00;
  --mercury-tone: #a5a5a5;
  --venus-tone: #e3bb76;
  --earth-tone: #2d5ff5;
  --mars-tone: #e27b58;
  --jupiter-tone: #d39c7e;
  --saturn-tone: #c5ab6e;
  --uranus-tone: #b5e1e2;
  --neptune-tone: #3f54ba;
  --pluto-tone: #968478;

  /* Spacing */
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 2rem;
  --space-lg: 4rem;
  --space-xl: 8rem;

  /* Typography */
  --font-main: 'Vazirmatn', system-ui, -apple-system, sans-serif;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  background-color: var(--space-black);
  color: var(--space-light);
  font-family: var(--font-main);
  line-height: 1.6;
  overflow-x: hidden;
  direction: rtl;
  min-height: 100vh;
}

/* Background Stars Effect */
.stars-container {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: -1;
  background: radial-gradient(circle at center, #1b2735 0%, #090a0f 100%);
  overflow: hidden;
}

.star {
  position: absolute;
  background: white;
  border-radius: 50%;
  opacity: 0.5;
  animation: twinkle var(--duration) infinite ease-in-out;
}

@keyframes twinkle {
  0%, 100% { opacity: 0.3; transform: scale(1); }
  50% { opacity: 1; transform: scale(1.2); }
}

/* Layout Components */
.presentation-container {
  display: grid;
  grid-template-columns: 1fr;
  min-height: 100vh;
  width: 100%;
  position: relative;
}

.slide {
  padding: var(--space-lg);
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  width: 100%;
  opacity: 0;
  animation: slideIn 1.2s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

@keyframes slideIn {
  from { opacity: 0; transform: translateY(30px); }
  to { opacity: 1; transform: translateY(0); }
}

.content-wrapper {
  max-width: 1200px;
  width: 100%;
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: var(--space-lg);
  align-items: center;
}

@media (max-width: 968px) {
  .content-wrapper {
    grid-template-columns: 1fr;
    text-align: center;
  }
}

/* Typography Styles */
h1 {
  font-size: clamp(3rem, 8vw, 6rem);
  font-weight: 900;
  margin-bottom: var(--space-sm);
  background: linear-gradient(to bottom, #fff, #ccc);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  filter: drop-shadow(0 0 20px rgba(255,255,255,0.2));
}

.planet-title {
  font-size: clamp(2.5rem, 6vw, 4.5rem);
  margin-bottom: var(--space-md);
  color: var(--planet-color, var(--accent-gold));
  text-shadow: 0 0 30px var(--planet-shadow, rgba(255, 215, 0, 0.3));
}

.description {
  font-size: 1.25rem;
  max-width: 600px;
  margin-bottom: var(--space-md);
  color: rgba(255,255,255,0.8);
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: var(--space-sm);
  width: 100%;
}

.stat-card {
  background: rgba(255, 255, 255, 0.08);
  padding: var(--space-sm);
  border-radius: 16px;
  border: 1px solid rgba(255, 255, 255, 0.1);
  transition: transform 0.3s ease;
}

.stat-card:hover {
  transform: translateY(-5px);
  background: rgba(255, 255, 255, 0.08);
}

.stat-label {
  font-size: 0.8rem;
  color: rgba(255,255,255,0.5);
  display: block;
}

.stat-value {
  font-size: 1.1rem;
  font-weight: bold;
  color: var(--planet-color, white);
}

/* Planet Visuals */
.visual-container {
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
}

.planet-sphere {
  width: min(80%, 500px);
  aspect-ratio: 1/1;
  border-radius: 50%;
  position: relative;
  background-size: cover;
  box-shadow: inset -20px -20px 50px rgba(0,0,0,0.8),
              0 0 60px var(--planet-shadow);
  animation: rotatePlanet 40s linear infinite;
}

.planet-sphere.sun {
  background: radial-gradient(circle at center, #fff 0%, #ffd700 30%, #ff8c00 60%, #ff4500 100%);
  box-shadow: 0 0 50px #ff8c00, 0 0 80px rgba(255, 140, 0, 0.3);
  animation: pulseSun 4s ease-in-out infinite;
}

@keyframes rotatePlanet {
  from { background-position: 0% 0%; }
  to { background-position: 200% 0%; }
}

@keyframes pulseSun {
  0%, 100% { transform: scale(1); filter: brightness(1); }
  50% { transform: scale(1.05); filter: brightness(1.2); }
}

/* Rings for Saturn/Uranus */
.rings {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%) rotateX(75deg);
  border: 15px solid rgba(197, 171, 110, 0.4);
  border-radius: 50%;
  width: 160%;
  height: 160%;
  pointer-events: none;
}

/* Navigation Controls */
.nav-controls {
  position: fixed;
  bottom: var(--space-md);
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: var(--space-sm);
  z-index: 100;
  background: rgba(0,0,0,0.75);
  padding: var(--space-xs) var(--space-sm);
  border-radius: 50px;
  border: 1px solid rgba(255,255,255,0.1);
}

.nav-btn {
  background: none;
  border: none;
  color: white;
  padding: 0.5rem 1rem;
  cursor: pointer;
  text-decoration: none;
  font-weight: bold;
  font-size: 0.9rem;
  transition: all 0.3s ease;
  border-radius: 20px;
}

.nav-btn:hover {
  background: rgba(255,255,255,0.1);
  color: var(--accent-gold);
}

.nav-btn.active {
  background: var(--accent-gold);
  color: var(--space-black);
}

/* Utility Classes */
.placeholder-image.planet {
  width: 100%;
  height: 100%;
  border-radius: 50%;
  background: linear-gradient(45deg, #1a1a1a, #333);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

.placeholder-image.planet::after {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 0;
  background: radial-gradient(circle at 30% 30%, rgba(255,255,255,0.1) 0%, transparent 70%);
}

.scroll-hint {
  position: absolute;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%);
  text-align: center;
  font-size: 0.8rem;
  opacity: 0.6;
  animation: bounce 2s infinite;
}

@keyframes bounce {
  0%, 20%, 50%, 80%, 100% {transform: translateY(0) translateX(-50%);}
  40% {transform: translateY(-10px) translateX(-50%);}
  60% {transform: translateY(-5px) translateX(-50%);}
}

/* Animations for specific planets */
.float-anim {
  animation: floating 6s ease-in-out infinite;
}

@keyframes floating {
  0% { transform: translateY(0px); }
  50% { transform: translateY(-20px); }
  100% { transform: translateY(0px); }
}