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

html, body {
  width: 100%;
  height: 100%;
  background: #000;
  overflow: hidden;
}

body {
  font-family: 'Helvetica Neue', Arial, "Apple SD Gothic Neo", "Malgun Gothic", sans-serif;
  color: #ffffff;
}

#scene {
  width: 100%;
  height: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: clamp(14px, 2.4vh, 26px);
}

#title {
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
}

#title-main {
  font-size: clamp(20px, 2.6vw, 30px);
  font-weight: 700;
  letter-spacing: 0.04em;
  color: #f5f5f5;
}

#title-sub {
  font-size: clamp(11px, 1.2vw, 14px);
  font-style: italic;
  font-weight: 400;
  letter-spacing: 0.02em;
  color: #b7b7b7;
}

#tank-wrap {
  position: relative;
  /* medium-sized tank: not full screen, plenty of black negative space around it */
  width: min(52vw, 52vh, 620px);
  height: min(52vw, 52vh, 620px);
}

#tank {
  position: relative;
  width: 100%;
  height: 100%;
  overflow: hidden;
  background: #000;
  box-shadow: 0 0 60px 6px rgba(120, 200, 255, 0.06);
}

#pixi-canvas {
  display: block;
  width: 100%;
  height: 100%;
}

#credit {
  font-size: clamp(10px, 1.1vw, 12px);
  letter-spacing: 0.08em;
  color: #7d7d7d;
  text-align: center;
}

/* --- start overlay --- */
#start-overlay {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0, 0, 0, 0.55);
  backdrop-filter: blur(2px);
  transition: opacity 0.6s ease;
  z-index: 5;
}

#start-overlay.hidden {
  opacity: 0;
  pointer-events: none;
}

#start-btn {
  padding: 16px 26px;
  border-radius: 999px;
  border: 1px solid rgba(255, 255, 255, 0.35);
  background: rgba(255, 255, 255, 0.06);
  color: #fff;
  font-size: 13px;
  line-height: 1.6;
  letter-spacing: 0.05em;
  cursor: pointer;
  transition: background 0.2s ease, transform 0.2s ease;
}

#start-btn span {
  font-size: 10px;
  color: #b9b9b9;
  letter-spacing: 0.15em;
}

#start-btn:hover {
  background: rgba(255, 255, 255, 0.14);
  transform: scale(1.03);
}

#cam-denied {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  font-size: 12px;
  line-height: 1.7;
  color: #ccc;
  background: rgba(0, 0, 0, 0.75);
  padding: 24px;
  z-index: 6;
}

#error-box {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: left;
  font-size: 11px;
  line-height: 1.6;
  color: #ff8a8a;
  background: rgba(0, 0, 0, 0.88);
  padding: 20px;
  white-space: pre-wrap;
  word-break: break-word;
  font-family: "SF Mono", Consolas, monospace;
  z-index: 10;
}

.hidden {
  display: none !important;
}