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

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Helvetica Neue', Helvetica, Arial, sans-serif;
  background: #000;
  color: #fff;
  overflow-x: hidden;
}

#root {
  width: 100%;
  min-height: 100vh;
}

/* Intro instruction section - appears before Scene01 */
.intro-instruction {
  position: relative;
  z-index: 200;
  width: 100vw;
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: #000;
}

.intro-instruction__text {
  padding: 1.5rem 2rem;
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(10px);
  border-radius: 8px;
  
  font-family: -apple-system, BlinkMacSystemFont, 'Helvetica Neue', Helvetica, Arial, sans-serif;
  font-size: 1.2rem;
  font-weight: 300;
  color: white;
  text-align: center;
  line-height: 1.5;
  letter-spacing: 0.02em;
  
  max-width: 550px;
  
  animation: fadeInUp 1.5s ease-out forwards;
}

.intro-instruction__signature {
  margin-top: 1rem;
  font-style: italic;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Responsive adjustments for intro */
@media (max-width: 768px) {
  .intro-instruction__text {
    font-size: 1rem;
    padding: 1.2rem 1.5rem;
    max-width: 85%;
  }
}