html, body {
  margin: 0;
  padding: 0;
  width: 100%;
  height: 100%;
  font-family: 'Noto Sans KR', 'Noto Sans', sans-serif;
  overflow: hidden;
  background: radial-gradient(circle at center, #2c3336 0%, #2c3336 60%, #252a2c 100%);
}

#title-bar {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  min-height: 48px;
  background: linear-gradient(to bottom, #0e0e0e, #1a1a1a);
  color: #fff;
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  padding: 6px 20px;
  box-sizing: border-box;
  gap: 10px 16px;
  z-index: 60;
  border-bottom: 1px solid rgba(255,255,255,0.12);
  justify-content: flex-start;
}

#sub-title::before {
  content: "|";
  color: #999;
  margin-right: 8px;
  opacity: 0.8;
}

#main-title {
  font-family: 'Noto Serif KR', 'Noto Serif', serif;
  font-size: 1.4em;
  font-weight: 700;
  letter-spacing: 0.02em;
  white-space: nowrap;
}

html[lang="en"] #main-title {
  font-family: 'Noto Sans', 'Noto Sans KR', sans-serif;
  font-weight: 700;
}

#sub-title {
  font-family: 'Noto Sans KR', 'Noto Sans', sans-serif;
  font-size: 0.95em;
  opacity: 0.85;
  overflow: hidden;
  text-overflow: ellipsis;
  flex: 1 1 auto;
  min-width: 180px;
}

model-viewer {
  width: 100%;
  height: 100%;
  position: absolute;
  top: 0;
  left: 0;
  --poster-color: transparent;
}

.controls {
  position: absolute;
  bottom: 28px;
  right: 28px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  z-index: 50;
}

.control-btn {
  width: 56px;
  height: 56px;
  border: none;
  border-radius: 50%;
  background: rgba(30,30,30,0.92);
  color: #fff;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  box-shadow: 0 6px 18px rgba(0,0,0,0.45);
  transition: all 0.16s ease-in-out;
  display: flex;
  align-items: center;
  justify-content: center;
  backdrop-filter: blur(4px);
}

.control-btn span.icon {
  display: block;
  font-size: 18px;
  line-height: 1;
}

.control-btn:hover {
  background: #6c63ff;
  transform: scale(1.06);
  box-shadow: 0 0 12px #6c63ff66, 0 0 28px #6c63ff33;
}

.control-btn:active { transform: scale(0.96); }

#model-error {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  z-index: 45;
  display: none;
  max-width: calc(100% - 48px);
  padding: 14px 18px;
  border-radius: 10px;
  background: rgba(0,0,0,0.65);
  color: rgba(255,255,255,0.88);
  font-size: 14px;
  text-align: center;
  line-height: 1.55;
  pointer-events: none;
}

@media (max-width: 768px) {
  #title-bar {
    flex-direction: column;
    align-items: flex-start;
    padding: 8px 14px;
    gap: 4px;
  }
  #main-title { font-size: 1.1em; }
  #sub-title {
    font-size: 0.9em;
    opacity: 0.9;
    white-space: normal;
  }
  #sub-title::before { display: none; }
  .controls { bottom: 18px; right: 18px; gap: 8px; }
  .control-btn { width: 44px; height: 44px; font-size: 12px; }
}