:root {
  --bg: #060b14;
  --bg-2: #0b1524;
  --panel: rgba(16, 25, 42, 0.86);
  --panel-line: rgba(126, 178, 170, 0.16);
  --text: #e8f2ee;
  --muted: #8fa6a6;
  --green: #46e08a;
  --green-deep: #17a86c;
  --amber: #ffc861;
  --danger: #ff7a6b;
  --radius: 18px;
  font-synthesis-weight: none;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  min-height: 100%;
  background:
    radial-gradient(1100px 620px at 12% -10%, rgba(29, 122, 96, 0.34), transparent 62%),
    radial-gradient(900px 540px at 92% 4%, rgba(28, 78, 140, 0.28), transparent 60%),
    linear-gradient(180deg, var(--bg), var(--bg-2) 70%, #060a12);
  color: var(--text);
  font-family: "Inter", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  -webkit-font-smoothing: antialiased;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  background-image: linear-gradient(rgba(120, 200, 180, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(120, 200, 180, 0.05) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(circle at 50% 30%, #000 30%, transparent 78%);
  pointer-events: none;
}

.app {
  position: relative;
  width: min(1080px, 100% - 32px);
  margin: 0 auto;
  padding: 24px 0 28px;
  display: flex;
  flex-direction: column;
  gap: 18px;
  min-height: 100vh;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

.brand { display: flex; align-items: center; gap: 12px; }

.logo {
  width: 44px; height: 44px;
  display: grid; place-items: center;
  border-radius: 14px;
  background: linear-gradient(150deg, rgba(70, 224, 138, 0.22), rgba(23, 168, 108, 0.06));
  border: 1px solid rgba(70, 224, 138, 0.34);
  box-shadow: 0 8px 24px rgba(23, 168, 108, 0.22);
}

.brand-text h1 { margin: 0; font-size: 20px; letter-spacing: 0.02em; }
.brand-text p { margin: 2px 0 0; font-size: 12px; color: var(--muted); }

.stats { display: flex; gap: 8px; }

.stat {
  min-width: 74px;
  padding: 8px 12px;
  border-radius: 14px;
  background: var(--panel);
  border: 1px solid var(--panel-line);
  display: flex;
  flex-direction: column;
  gap: 2px;
  text-align: center;
}

.stat span { font-size: 11px; color: var(--muted); letter-spacing: 0.06em; }
.stat strong { font-size: 20px; font-variant-numeric: tabular-nums; color: var(--green); }
.stat:nth-child(2) strong { color: var(--amber); }
.stat:nth-child(3) strong { color: #9fd6ff; }

.stage {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 262px;
  gap: 18px;
  align-items: start;
}

.board-wrap {
  position: relative;
  border-radius: 24px;
  padding: 10px;
  background: linear-gradient(160deg, rgba(38, 66, 78, 0.55), rgba(10, 18, 30, 0.9));
  border: 1px solid rgba(120, 210, 180, 0.18);
  box-shadow: 0 30px 70px -30px rgba(0, 0, 0, 0.9), inset 0 1px 0 rgba(255, 255, 255, 0.06);
}

canvas {
  display: block;
  width: 100%;
  aspect-ratio: 1 / 1;
  border-radius: 16px;
  background: #071120;
  touch-action: none;
}

.overlay {
  position: absolute;
  inset: 10px;
  border-radius: 16px;
  display: grid;
  place-items: center;
  background: rgba(6, 12, 22, 0.72);
  backdrop-filter: blur(7px);
  -webkit-backdrop-filter: blur(7px);
  transition: opacity 0.25s ease;
  text-align: center;
  padding: 20px;
}

.overlay.is-hidden { opacity: 0; pointer-events: none; }

.overlay-panel { max-width: 340px; display: flex; flex-direction: column; align-items: center; gap: 10px; }

.badge {
  font-size: 11px;
  letter-spacing: 0.16em;
  padding: 4px 10px;
  border-radius: 999px;
  color: var(--green);
  background: rgba(70, 224, 138, 0.12);
  border: 1px solid rgba(70, 224, 138, 0.3);
}

.overlay h2 { margin: 0; font-size: 24px; }
.overlay p { margin: 0; font-size: 13px; line-height: 1.6; color: var(--muted); }
.overlay-tip { font-size: 11px; color: rgba(143, 166, 166, 0.7); }

.side { display: flex; flex-direction: column; gap: 12px; }

.card {
  border-radius: var(--radius);
  background: var(--panel);
  border: 1px solid var(--panel-line);
  padding: 14px;
}

.card h3 {
  margin: 0 0 10px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.14em;
  color: var(--muted);
  text-transform: uppercase;
}

.segmented {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 6px;
  padding: 4px;
  border-radius: 12px;
  background: rgba(7, 14, 24, 0.8);
  border: 1px solid rgba(126, 178, 170, 0.12);
}

.seg {
  appearance: none;
  border: 0;
  padding: 8px 6px;
  border-radius: 9px;
  background: transparent;
  color: var(--muted);
  font-size: 13px;
  cursor: pointer;
  transition: background 0.18s ease, color 0.18s ease;
}

.seg.is-active { background: rgba(70, 224, 138, 0.16); color: var(--green); box-shadow: inset 0 0 0 1px rgba(70, 224, 138, 0.34); }

.hint { margin: 10px 0 0; font-size: 12px; line-height: 1.55; color: var(--muted); }

.keys { list-style: none; margin: 0 0 12px; padding: 0; display: flex; flex-direction: column; gap: 8px; }
.keys li { display: flex; align-items: center; gap: 8px; font-size: 12px; color: var(--muted); }
.keys em { font-style: normal; }
.keycaps { display: inline-flex; gap: 3px; }

kbd {
  display: inline-grid;
  place-items: center;
  min-width: 22px;
  height: 22px;
  padding: 0 6px;
  border-radius: 6px;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-bottom-width: 2px;
  font-family: inherit;
  font-size: 11px;
  color: #d6e6e0;
}

.row { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }

.btn {
  appearance: none;
  border: 1px solid transparent;
  border-radius: 12px;
  padding: 10px 16px;
  font-size: 14px;
  font-family: inherit;
  cursor: pointer;
  transition: transform 0.12s ease, background 0.18s ease, border-color 0.18s ease, opacity 0.18s ease;
}

.btn:active { transform: translateY(1px); }
.btn:disabled { opacity: 0.42; cursor: not-allowed; }

.btn.primary {
  background: linear-gradient(160deg, #4cf095, #17a86c);
  color: #052016;
  font-weight: 700;
  box-shadow: 0 12px 26px -12px rgba(70, 224, 138, 0.8);
}

.btn.ghost {
  background: rgba(255, 255, 255, 0.04);
  border-color: rgba(126, 178, 170, 0.2);
  color: var(--text);
}

.btn.ghost:hover:not(:disabled) { background: rgba(70, 224, 138, 0.1); border-color: rgba(70, 224, 138, 0.34); }

.dpad-card { display: flex; flex-direction: column; }

.dpad {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  grid-template-rows: repeat(3, 1fr);
  gap: 6px;
  width: min(190px, 100%);
  margin: 0 auto;
}

.dbtn {
  aspect-ratio: 1 / 1;
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(126, 178, 170, 0.18);
  color: #cfe8de;
  font-size: 14px;
  cursor: pointer;
  touch-action: manipulation;
  -webkit-user-select: none;
  user-select: none;
}

.dbtn:active { background: rgba(70, 224, 138, 0.2); border-color: rgba(70, 224, 138, 0.5); }
.dbtn.up { grid-area: 1 / 2; }
.dbtn.left { grid-area: 2 / 1; }
.dbtn.pause { grid-area: 2 / 2; font-size: 11px; letter-spacing: 0.06em; color: var(--muted); }
.dbtn.right { grid-area: 2 / 3; }
.dbtn.down { grid-area: 3 / 2; }

.foot { margin-top: auto; text-align: center; font-size: 11px; color: rgba(143, 166, 166, 0.6); }

button:focus-visible, canvas:focus-visible { outline: 2px solid rgba(70, 224, 138, 0.75); outline-offset: 2px; }

@media (max-width: 860px) {
  .stage { grid-template-columns: 1fr; }
  .side { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
  .dpad-card { grid-column: span 2; }
  .stats { width: 100%; justify-content: space-between; }
  .stat { flex: 1; min-width: 0; }
}

@media (max-width: 520px) {
  .app { width: 100%; padding: 14px 12px 20px; gap: 12px; }
  .brand-text p { display: none; }
  .side { grid-template-columns: 1fr; }
  .dpad-card { grid-column: span 1; }
  .overlay h2 { font-size: 20px; }
  .stat strong { font-size: 17px; }
}