/* 全屏画布，没有滚动条 / full-screen canvas, no scrollbars */
html, body {
  margin: 0;
  padding: 0;
  overflow: hidden;
  background: #16130f;
  color: #f2efe4;
  font-family: "Avenir Next", "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
}

canvas {
  display: block;
}

/* 开始界面 / start screen */
#intro {
  position: fixed;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: #16130f;
  z-index: 10;
  padding: 16px;
  overflow-y: auto;
}

.card {
  max-width: 640px;
  padding: 28px 32px;
  background: rgba(30, 26, 20, 0.92);
  border: 2px solid #e8a33d;
  border-radius: 12px;
  text-align: center;
}

.card h1 {
  font-size: clamp(2.2rem, 8vw, 4rem);
  margin: 0;
  letter-spacing: 0.06em;
  font-weight: 600;
}

.sub {
  margin: 6px 0 18px;
  opacity: 0.8;
}

.card ul {
  list-style: none;
  padding: 0;
  margin: 0 0 14px;
  line-height: 1.8;
  text-align: left;
}

.tip {
  font-size: 0.9em;
  opacity: 0.75;
  margin: 0 0 20px;
}

kbd {
  border: 1px solid currentColor;
  border-radius: 4px;
  padding: 0 6px;
  font-size: 0.85em;
}

#start {
  font-family: inherit;
  font-size: 1.15rem;
  padding: 12px 32px;
  border: none;
  border-radius: 999px;
  background: #3f88a8;
  color: #f2efe4;
  cursor: pointer;
}

#start:hover {
  filter: brightness(1.15);
}

/* 状态提示 / status line */
#status {
  position: fixed;
  left: 16px;
  bottom: 12px;
  font-size: 0.85rem;
  padding: 3px 8px;
  border-radius: 4px;
  background: rgba(0, 0, 0, 0.55);
  color: #fff;
  pointer-events: none;
  max-width: calc(100vw - 48px);
}