* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
}

body {
  width: 100vw;
  height: 100vh;
  overflow: hidden;
  background: black;
}

/* START SCREEN */
#start {
  position: fixed;
  inset: 0;
  background: black;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 10;
}

#start button {
  padding: 16px 28px;
  font-size: 16px;
  border-radius: 30px;
  border: none;
}

/* LOADER */
#loader {
  position: fixed;
  inset: 0;
  z-index: 4;
  display: none;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  pointer-events: none;
}

#loader p {
  color: white;
  margin-top: 12px;
  font-size: 14px;
  letter-spacing: 1px;
  opacity: 0.8;
}

.spinner {
  width: 40px;
  height: 40px;
  border: 3px solid rgba(255,255,255,0.2);
  border-top-color: white;
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* CAMERA */
#camera {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  z-index: 0;
}

/* OVERLAY */
.overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.6);
  backdrop-filter: blur(4px);
  z-index: 1;
}

/* MODEL VIEWER */
model-viewer {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  z-index: 2;

  opacity: 1;
  transition: opacity 0.35s ease-in-out;
  --poster-color: transparent;
}

model-viewer.fade-out {
  opacity: 0;
}

/* CONTROLS */
.controls {
  position: fixed;
  bottom: 90px;
  width: 100%;
  padding: 0 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  z-index: 3;
}

.controls button {
  background: rgba(255,255,255,0.18);
  border: none;
  color: white;
  font-size: 22px;
  padding: 16px 18px;
  border-radius: 50%;
}

.title {
  color: white;
  font-size: 18px;
  letter-spacing: 2px;
  text-transform: uppercase;
}

/* AR BUTTON */
.ar-btn {
  position: fixed;
  bottom: 25px;
  left: 50%;
  transform: translateX(-50%);
  padding: 14px 28px;
  background: white;
  color: black;
  border: none;
  border-radius: 30px;
  font-size: 14px;
  z-index: 3;
}