:root {
  --bg: #070911;
  --panel: #111a2d;
  --line: #2e436d;
  --ink: #e9efff;
  --muted: #a2b5df;
  --accent: #7af9d4;
  --hot: #ff9bc8;
  --warn: #ffd790;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  font-family: "Courier New", Courier, monospace;
  background:
    radial-gradient(circle at 12% -10%, rgba(122, 249, 212, 0.16), transparent 42%),
    radial-gradient(circle at 80% 0%, rgba(255, 155, 200, 0.16), transparent 40%),
    linear-gradient(180deg, #0d1323, var(--bg));
  color: var(--ink);
  display: grid;
  place-items: center;
  padding: 20px;
}

.app {
  width: min(900px, 100%);
  border: 2px solid var(--line);
  border-radius: 12px;
  background: linear-gradient(180deg, rgba(16, 24, 42, 0.96), rgba(8, 12, 25, 0.98));
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.52);
  padding: 18px;
}

.back {
  color: #ffd7a4;
  text-decoration: none;
  font-size: 0.9rem;
}

.topbar h1 {
  margin: 8px 0 4px;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 1px;
}

.topbar p {
  margin: 0 0 14px;
  color: #bfd0fb;
}

.hud {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 8px;
}

.hud div {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #131d35;
  padding: 10px;
  text-align: center;
}

.label {
  display: block;
  font-size: 0.72rem;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 4px;
}

.deck,
.tips {
  margin-top: 12px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #101a31;
  padding: 12px;
}

.track-wrap {
  position: relative;
  height: 60px;
  border: 1px solid #486092;
  border-radius: 999px;
  background: linear-gradient(180deg, #0e1528, #0a1222);
  overflow: hidden;
}

.track-wrap::before {
  content: "";
  position: absolute;
  inset: 14px 0;
  background: repeating-linear-gradient(90deg, rgba(255, 255, 255, 0.05) 0 2px, transparent 2px 8px);
}

.target,
.playhead {
  position: absolute;
  top: 0;
  width: 18px;
  height: 100%;
  transform: translateX(-50%);
  border-radius: 8px;
}

.target {
  background: linear-gradient(180deg, rgba(255, 155, 200, 0.28), rgba(255, 155, 200, 0.56));
  border: 1px solid rgba(255, 155, 200, 0.88);
  box-shadow: 0 0 12px rgba(255, 155, 200, 0.5);
}

.playhead {
  width: 6px;
  background: linear-gradient(180deg, #95f7ff, #7af9d4);
  border: 1px solid #d6fcff;
  box-shadow: 0 0 12px rgba(122, 249, 212, 0.6);
}

.track-markers {
  margin-top: 8px;
  display: flex;
  justify-content: space-between;
  color: #91a7da;
  font-size: 0.75rem;
}

.controls {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 8px;
  margin-top: 12px;
}

button {
  font: inherit;
  color: var(--ink);
  border: 1px solid #5a80bb;
  border-radius: 8px;
  padding: 10px;
  background: linear-gradient(180deg, #2a5e98, #1a3f66);
  cursor: pointer;
  transition: filter 0.15s ease, transform 0.08s ease;
}

button:hover { filter: brightness(1.08); }
button:active { transform: translateY(1px); }

.primary {
  border-color: #f6b4da;
  background: linear-gradient(180deg, #85416a, #5b2849);
}

.hint,
.status {
  margin: 10px 0 0;
  color: #d4defd;
}

.status.good { color: var(--accent); }
.status.bad { color: #ff99ad; }

.tips h2 {
  margin: 0 0 8px;
  text-transform: uppercase;
  font-size: 1rem;
  color: var(--warn);
}

.tips ul {
  margin: 0;
  padding-left: 18px;
  display: grid;
  gap: 4px;
  color: #d9e4ff;
}

@media (max-width: 700px) {
  .hud {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .controls {
    grid-template-columns: 1fr;
  }
}