:root {
  --bg-1: #040507;
  --bg-2: #0e1220;
  --line: #d4ffe8;
  --line-muted: #9ad9b8;
  --panel: rgba(10, 14, 24, 0.62);
  --panel-border: rgba(212, 255, 232, 0.22);
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  width: 100%;
  height: 100%;
  overflow: hidden;
  background: radial-gradient(circle at 20% 15%, #1b243d 0%, var(--bg-2) 28%, var(--bg-1) 70%);
  color: var(--line);
  font-family: "Avenir Next Condensed", "Helvetica Neue", "Segoe UI", sans-serif;
}

#gameCanvas {
  position: fixed;
  inset: 0;
  width: 100vw;
  height: 100vh;
  display: block;
}

.hud {
  position: fixed;
  top: 14px;
  left: 14px;
  right: 14px;
  z-index: 2;
  display: flex;
  justify-content: space-between;
  gap: 12px;
  padding: 10px 14px;
  border: 1px solid var(--panel-border);
  border-radius: 10px;
  background: var(--panel);
  backdrop-filter: blur(2px);
  letter-spacing: 0.07em;
  text-transform: uppercase;
}

.hud-item {
  display: flex;
  align-items: baseline;
  gap: 8px;
  min-width: 0;
}

.label {
  color: var(--line-muted);
  font-size: 0.72rem;
}

#score,
#lives,
#level {
  font-weight: 700;
  font-size: 1rem;
}

.overlay {
  position: fixed;
  left: 50%;
  top: 50%;
  z-index: 3;
  width: min(680px, calc(100vw - 40px));
  transform: translate(-50%, -50%) scale(0.97);
  opacity: 0;
  padding: 28px 24px;
  border: 1px solid var(--panel-border);
  border-radius: 16px;
  background: linear-gradient(140deg, rgba(4, 7, 13, 0.9), rgba(11, 18, 34, 0.88));
  text-align: center;
  pointer-events: none;
  transition: opacity 180ms ease, transform 180ms ease;
}

.overlay.show {
  opacity: 1;
  transform: translate(-50%, -50%) scale(1);
}

.overlay h1 {
  margin: 0 0 14px;
  font-size: clamp(1.8rem, 5vw, 3rem);
  letter-spacing: 0.24em;
  text-indent: 0.24em;
  color: #effff4;
}

.overlay p {
  margin: 0;
  font-size: clamp(0.95rem, 2.7vw, 1.25rem);
}

.overlay .help {
  margin-top: 16px;
  color: var(--line-muted);
  font-size: clamp(0.8rem, 2.3vw, 0.96rem);
}

@media (max-width: 640px) {
  .hud {
    top: 10px;
    left: 10px;
    right: 10px;
    padding: 8px 10px;
    gap: 8px;
  }

  .label {
    font-size: 0.64rem;
  }

  #score,
  #lives,
  #level {
    font-size: 0.9rem;
  }
}