* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  -webkit-touch-callout: none;
  -webkit-user-select: none;
  user-select: none;
}

html, body {
  width: 100%;
  height: 100%;
  overflow: hidden;
  background: #bae6fd;
  touch-action: none;
  font-family: -apple-system, BlinkMacSystemFont, "Comic Sans MS", "Segoe UI", Roboto, sans-serif;
}

/* Velká přehledná navigační lišta nahoře */
.top-bar {
  position: absolute;
  top: 14px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 12px;
  background: rgba(255, 255, 255, 0.9);
  padding: 8px 14px;
  border-radius: 40px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
  backdrop-filter: blur(10px);
  z-index: 100;
}

.nav-btn {
  display: flex;
  align-items: center;
  gap: 8px;
  background: #f1f5f9;
  border: 3px solid transparent;
  border-radius: 30px;
  padding: 8px 18px;
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.34, 1.56, 0.64, 1);
  outline: none;
}

.nav-btn .icon {
  font-size: 32px;
  line-height: 1;
}

.nav-btn .label {
  font-size: 18px;
  font-weight: 900;
  color: #334155;
}

.nav-btn:active {
  transform: scale(0.92);
}

.nav-btn.active {
  background: #ffffff;
  border-color: #f59e0b;
  box-shadow: 0 4px 14px rgba(245, 158, 11, 0.35);
  transform: scale(1.06);
}

.nav-btn.active .label {
  color: #b45309;
}

/* Plátno */
#gameCanvas {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: block;
  touch-action: none;
}

@media (max-width: 600px) {
  .top-bar {
    top: 8px;
    gap: 8px;
    padding: 6px 10px;
  }
  .nav-btn {
    padding: 6px 10px;
  }
  .nav-btn .icon {
    font-size: 26px;
  }
  .nav-btn .label {
    display: none; /* na malém displeji stačí velké ikony */
  }
}