:root {
  --text: #f4f7ff;
  --muted: #b9c7e8;
  --accent: #7bf2e6;
  --shadow: rgba(4, 8, 20, 0.55);
}

* {
  box-sizing: border-box;
}

html,
body {
  width: 100%;
  height: 100%;
  margin: 0;
  overflow: hidden;
  font-family: "Avenir Next", "PingFang SC", "Noto Sans SC", sans-serif;
  background: #030712;
}

#stage {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
}

.hud {
  position: fixed;
  left: clamp(18px, 4vw, 60px);
  top: clamp(18px, 4vw, 48px);
  width: min(90vw, 540px);
  color: var(--text);
  padding: clamp(16px, 2vw, 22px);
  border-radius: 18px;
  background: linear-gradient(145deg, rgba(2, 8, 23, 0.65), rgba(12, 19, 49, 0.42));
  box-shadow: 0 24px 48px var(--shadow);
  backdrop-filter: blur(6px);
}

.badge {
  margin: 0;
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent);
}

h1 {
  margin: 10px 0 10px;
  font-size: clamp(1.35rem, 4.5vw, 2.2rem);
  line-height: 1.15;
  font-weight: 700;
}

.subtitle {
  margin: 0;
  font-size: clamp(0.95rem, 2.7vw, 1.1rem);
  color: var(--muted);
  min-height: 1.4em;
}

.control-panel {
  margin-top: 14px;
}

.control-panel label {
  display: block;
  margin-bottom: 7px;
  font-size: 0.82rem;
  color: rgba(225, 235, 255, 0.9);
}

.control-row {
  display: flex;
  gap: 8px;
}

.quick-buttons {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 8px;
  margin-top: 8px;
}

.tuning-row {
  margin-top: 10px;
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 8px;
}

.tuning-row label {
  margin: 0;
  font-size: 0.8rem;
  color: rgba(225, 235, 255, 0.88);
}

.tuning-row input[type="range"] {
  width: 100%;
  accent-color: #7bf2e6;
}

#speedValue {
  min-width: 3.8em;
  text-align: right;
  font-size: 0.8rem;
  color: rgba(218, 241, 255, 0.85);
  font-variant-numeric: tabular-nums;
}

.action-buttons {
  margin-top: 8px;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px;
}

.control-row input {
  flex: 1;
  min-width: 0;
  border: 1px solid rgba(145, 207, 255, 0.35);
  border-radius: 10px;
  padding: 10px 12px;
  font-size: 0.95rem;
  color: var(--text);
  background: rgba(4, 12, 28, 0.62);
  outline: none;
}

.control-row input::placeholder {
  color: rgba(197, 210, 235, 0.62);
}

.control-row input:focus {
  border-color: rgba(123, 242, 230, 0.95);
  box-shadow: 0 0 0 3px rgba(123, 242, 230, 0.15);
}

.control-row button,
.quick-buttons button,
.action-buttons button {
  border: none;
  border-radius: 10px;
  padding: 0 14px;
  min-height: 42px;
  font-size: 0.95rem;
  font-weight: 700;
  color: #03111d;
  background: linear-gradient(135deg, #7bf2e6, #93dcff);
  cursor: pointer;
  transition: transform 160ms ease, box-shadow 160ms ease;
}

.quick-buttons button {
  min-height: 36px;
  font-size: 0.84rem;
  font-weight: 650;
  padding: 0 8px;
}

.control-row button:hover,
.quick-buttons button:hover,
.action-buttons button:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 16px rgba(126, 238, 255, 0.4);
}

.action-buttons button {
  min-height: 36px;
  font-size: 0.82rem;
  padding: 0 10px;
}

#favoriteButton.is-saved {
  background: linear-gradient(135deg, #ffe06a, #ffb067);
}

.favorite-status {
  margin: 8px 0 0;
  font-size: 0.76rem;
  min-height: 1.35em;
  color: rgba(243, 228, 169, 0.9);
}

.control-status {
  margin: 8px 0 0;
  font-size: 0.78rem;
  min-height: 1.35em;
  color: rgba(208, 233, 255, 0.8);
}

.hint {
  margin: 14px 0 0;
  font-size: 0.86rem;
  color: rgba(225, 232, 255, 0.72);
}

@media (max-width: 640px) {
  .hud {
    right: 14px;
    left: 14px;
    width: auto;
    bottom: 14px;
    top: auto;
  }

  .control-row {
    flex-direction: column;
  }

  .control-row button {
    width: 100%;
  }

  .quick-buttons {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .quick-buttons button:last-child {
    grid-column: 1 / -1;
  }

  .tuning-row {
    grid-template-columns: 1fr;
  }

  #speedValue {
    text-align: left;
  }

  .action-buttons {
    grid-template-columns: 1fr;
  }
}