:root {
  --bg: #0b1426;
  --hud-bg: rgba(9, 18, 35, 0.8);
  --hud-border: rgba(144, 194, 255, 0.25);
  --text: #e6f2ff;
  --panel-bg: rgba(10, 21, 40, 0.86);
  --panel-border: rgba(166, 206, 255, 0.3);
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  width: 100%;
  height: 100%;
  overflow: hidden;
  background: radial-gradient(circle at 30% 20%, #19335d 0%, var(--bg) 55%, #070d19 100%);
  font-family: "Trebuchet MS", "Segoe UI", sans-serif;
  color: var(--text);
}

#game-canvas {
  width: 100vw;
  height: 100vh;
  display: block;
  touch-action: none;
}

.hud {
  position: fixed;
  left: 12px;
  top: 12px;
  padding: 10px 12px;
  border-radius: 8px;
  background: var(--hud-bg);
  border: 1px solid var(--hud-border);
  line-height: 1.3;
  font-size: 14px;
  z-index: 5;
}

.menu {
  position: fixed;
  inset: 0;
  display: grid;
  place-items: center;
  z-index: 10;
  background: rgba(4, 9, 18, 0.45);
  padding: 16px;
}

.menu.hidden {
  display: none;
}

.menu-card {
  width: min(520px, 100%);
  background: var(--panel-bg);
  border: 1px solid var(--panel-border);
  border-radius: 12px;
  padding: 16px;
  backdrop-filter: blur(4px);
}

.menu-card h1 {
  margin: 0 0 10px;
  font-size: 28px;
}

.menu-card h2 {
  margin: 14px 0 8px;
  font-size: 18px;
}

.menu-card label {
  display: block;
  margin-bottom: 4px;
  font-size: 14px;
}

.menu-card input {
  width: 100%;
  padding: 9px 10px;
  border-radius: 8px;
  border: 1px solid rgba(200, 225, 255, 0.35);
  background: rgba(6, 16, 31, 0.75);
  color: var(--text);
  font-size: 15px;
}

.menu-card button {
  margin-top: 10px;
  padding: 9px 14px;
  border-radius: 8px;
  border: 1px solid rgba(220, 238, 255, 0.45);
  background: rgba(43, 93, 153, 0.85);
  color: var(--text);
  font-weight: 700;
  cursor: pointer;
}

.menu-card button:disabled {
  opacity: 0.55;
  cursor: default;
}

.menu-message {
  min-height: 20px;
  margin-top: 8px;
  color: #d9ecff;
  font-size: 14px;
}

.scoreboard {
  margin: 0;
  padding-left: 20px;
  max-height: 260px;
  overflow: auto;
}

.scoreboard li {
  margin-bottom: 4px;
}

.hint {
  margin-top: 10px;
  font-size: 13px;
  color: rgba(222, 238, 255, 0.8);
}