* {
  box-sizing: border-box;
}

html,
body {
  width: 100%;
  height: 100%;
  margin: 0;
  overflow: hidden;
  font-family: Arial, Helvetica, sans-serif;
  background: #101014;
  color: #fff;
}

#scene-canvas {
  display: block;
  width: 100vw;
  height: 100vh;
}

.loading-screen {
  position: fixed;
  inset: 0;
  z-index: 20;
  display: grid;
  place-items: center;
  background: radial-gradient(circle at center, #22263a, #09090d 70%);
  transition: opacity 500ms ease, visibility 500ms ease;
}

.loading-screen.hidden {
  opacity: 0;
  visibility: hidden;
}

.loading-card {
  width: min(420px, calc(100vw - 40px));
  padding: 28px;
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: 18px;
  background: rgba(0, 0, 0, 0.35);
  text-align: center;
  backdrop-filter: blur(10px);
}

.loading-card h1 {
  margin: 0 0 20px;
  font-size: 24px;
  font-weight: 700;
}

.progress-track {
  height: 12px;
  overflow: hidden;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.15);
}

.progress-bar {
  width: 0%;
  height: 100%;
  border-radius: inherit;
  background: white;
  transition: width 180ms ease;
}

.ui-panel {
  position: fixed;
  left: 20px;
  bottom: 20px;
  z-index: 10;
  width: min(360px, calc(100vw - 40px));
  padding: 18px;
  border: 1px solid rgba(255, 255, 255, 0.16);
  border-radius: 16px;
  background: rgba(0, 0, 0, 0.48);
  backdrop-filter: blur(8px);
}

.ui-panel h2 {
  margin: 0 0 12px;
  font-size: 18px;
}

#name-form {
  display: flex;
  gap: 8px;
}

#name-input {
  min-width: 0;
  flex: 1;
  padding: 10px 12px;
  border: 1px solid rgba(255, 255, 255, 0.25);
  border-radius: 10px;
  background: rgba(255, 255, 255, 0.08);
  color: white;
}

#name-input::placeholder {
  color: rgba(255, 255, 255, 0.65);
}

button {
  padding: 10px 14px;
  border: 0;
  border-radius: 10px;
  background: #fff;
  color: #111;
  cursor: pointer;
  font-weight: 700;
}

#form-message {
  min-height: 18px;
  margin: 10px 0 0;
  color: rgba(255, 255, 255, 0.8);
  font-size: 14px;
}

.tooltip {
  position: fixed;
  z-index: 12;
  display: none;
  pointer-events: none;
  padding: 7px 10px;
  border-radius: 8px;
  background: rgba(0, 0, 0, 0.76);
  color: white;
  font-size: 13px;
  transform: translate(12px, 12px);
}

.tooltip.visible {
  display: block;
}