* { margin: 0; padding: 0; box-sizing: border-box; }
  body {
    background: radial-gradient(circle at 50% 30%, #1a2a4a 0%, #0b0f1e 60%, #05060d 100%);
    min-height: 100vh;
    display: flex; align-items: center; justify-content: center;
    font-family: "Segoe UI", "Microsoft YaHei", system-ui, sans-serif;
    color: #e8ecf7; overflow: hidden;
  }
  #wrap { position: relative; display: flex; align-items: center; justify-content: center; gap: 26px; flex-wrap: wrap; padding: 20px; }
  #left { text-align: center; }
  h1 {
    font-size: 22px; letter-spacing: 6px; font-weight: 600;
    background: linear-gradient(90deg,#5eead4,#a78bfa,#f472b6);
    -webkit-background-clip: text; background-clip: text; color: transparent;
    margin-bottom: 10px;
  }
  #stage {
    position: relative; margin: 0 auto;
    box-shadow: 0 0 0 1px rgba(255,255,255,.08), 0 20px 60px rgba(0,0,0,.6);
    border-radius: 14px; overflow: hidden;
    background: #0a0f1e;
  }
  canvas { display: block; background: transparent; border-radius: 14px; }
  /* 常驻右侧说明面板 */
  #panel {
    width: 256px; flex: 0 0 auto;
    background: rgba(15,23,42,.78); border: 1px solid rgba(255,255,255,.10);
    border-radius: 14px; padding: 16px 16px 14px;
    box-shadow: 0 12px 40px rgba(0,0,0,.5);
    text-align: left; align-self: center;
  }
  #panel h2 { font-size: 15px; letter-spacing: 3px; margin-bottom: 13px; color: #5eead4; font-weight: 600; text-align: center; }
  #panel .sec { margin-bottom: 13px; }
  #panel .sec-t { font-size: 12px; color: #94a3b8; letter-spacing: 1px; margin-bottom: 5px; font-weight: 600; }
  #panel ul { list-style: none; }
  #panel li { font-size: 12.5px; color: #c7d2fe; line-height: 1.8; display: flex; align-items: center; gap: 8px; }
  #panel li .dot { width: 12px; height: 12px; border-radius: 3px; flex: 0 0 auto; }
  #panel li .kbd {
    display: inline-block; min-width: 20px; text-align: center; padding: 0 6px;
    background: rgba(255,255,255,.08); border: 1px solid rgba(255,255,255,.16);
    border-radius: 4px; font-size: 11px; color: #e2e8f0; font-weight: 600; font-family: inherit;
  }
  #panel .note { font-size: 11px; color: #7a86a8; line-height: 1.65; }
  #panel .lv-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 6px; }
  #panel .lvbtn {
    padding: 6px 0; border: 1px solid rgba(255,255,255,.16); border-radius: 6px;
    background: rgba(255,255,255,.06); color: #c7d2fe; font-size: 12px; font-weight: 600;
    cursor: pointer; text-align: center; user-select: none; font-family: inherit;
  }
  #panel .lvbtn:hover { background: rgba(255,255,255,.16); }
  #panel .lvbtn.active { background: linear-gradient(90deg,#5eead4,#22d3ee); color: #062b33; border-color: transparent; }
  /* 隐藏关入口（❓）：低调、虚线、暗色，区别于常规选关 */
  #panel .lvbtn.hidden {
    border: 1px dashed rgba(255,255,255,.28); background: rgba(255,255,255,.03);
    color: #94a3b8; font-size: 13px;
  }
  #panel .lvbtn.hidden:hover { background: rgba(255,255,255,.12); color: #e2e8f0; }
  #panel .lvbtn.hidden.active { background: linear-gradient(90deg,#64748b,#475569); color: #fff; border-color: transparent; }
  @media (max-width: 1210px) { #panel { width: 210px; } }
  /* 移动端触控条 */
  #touchbar { display: none; margin-top: 12px; }
  .tb-btn {
    width: 70px; height: 44px; border: 1px solid rgba(255,255,255,.15);
    background: rgba(255,255,255,.06); color: #c7d2fe; border-radius: 10px;
    font-size: 20px; cursor: pointer; margin: 0 6px; user-select: none;
  }
  .tb-btn:active { background: rgba(255,255,255,.18); }
  @media (pointer: coarse) { #touchbar { display: block; } }