:root {
  --bg: #07080a;
  --panel: #101318;
  --panel-2: #151a21;
  --border: rgba(255, 255, 255, 0.08);
  --text: #e8edf3;
  --muted: #98a4b3;
  --accent: #35d6ff;
  --accent-soft: rgba(53, 214, 255, 0.16);
  --danger: #ff5470;
  --success: #69f0ae;
  --warning: #ffd166;
  --radius: 18px;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
}

body {
  background:
    radial-gradient(circle at top center, rgba(53, 214, 255, 0.08), transparent 32%),
    var(--bg);
  color: var(--text);
  font-family:
    ui-sans-serif,
    system-ui,
    -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    Roboto,
    Helvetica,
    Arial,
    sans-serif;
  line-height: 1.45;
  min-height: 100vh;
  padding: 24px 16px 48px;
}

.app {
  width: min(860px, 100%);
  margin: 0 auto;
  display: grid;
  gap: 18px;
}

.header {
  text-align: center;
  padding: 10px 0 0;
}

h1 {
  margin: 0;
  font-size: clamp(2rem, 4vw, 3.4rem);
  font-weight: 650;
  letter-spacing: -0.04em;
}

.subtitle {
  margin: 8px 0 0;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.16em;
  font-size: 0.82rem;
}

.status {
  margin: 10px 0 0;
  color: var(--warning);
  min-height: 1.2em;
  font-size: 0.92rem;
}

.panel {
  background: linear-gradient(180deg, rgba(255,255,255,0.02), rgba(255,255,255,0)), var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
  box-shadow: 0 16px 50px rgba(0, 0, 0, 0.28);
}

.visualizer-panel {
  display: grid;
  gap: 12px;
}

#visualizer {
  width: 100%;
  height: 220px;
  display: block;
  border-radius: 14px;
  background:
    radial-gradient(circle at center, rgba(53, 214, 255, 0.05), transparent 45%),
    #050709;
  border: 1px solid rgba(255, 255, 255, 0.05);
}

.timer {
  text-align: center;
  color: var(--accent);
  font-variant-numeric: tabular-nums;
  font-size: 1rem;
  letter-spacing: 0.04em;
}

.transport-panel {
  display: grid;
  gap: 16px;
}

.btn-primary {
  appearance: none;
  border: 0;
  border-radius: 999px;
  padding: 15px 28px;
  font-size: 1rem;
  font-weight: 750;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: #031018;
  background: var(--accent);
  cursor: pointer;
  box-shadow: 0 0 0 1px rgba(53, 214, 255, 0.18), 0 14px 36px rgba(53, 214, 255, 0.18);
  transition: transform 120ms ease, box-shadow 180ms ease, background 180ms ease;
}

.btn-primary:hover {
  transform: translateY(-1px);
}

.btn-primary.stop {
  background: var(--danger);
  color: white;
  box-shadow: 0 0 0 1px rgba(255, 84, 112, 0.2), 0 14px 36px rgba(255, 84, 112, 0.18);
}

.control-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 14px;
}

.control {
  display: grid;
  gap: 8px;
}

label {
  display: flex;
  justify-content: space-between;
  gap: 10px;
  color: var(--muted);
  font-size: 0.92rem;
}

label span {
  color: var(--accent);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

input[type="range"] {
  width: 100%;
  height: 38px;
  appearance: none;
  background: transparent;
  cursor: pointer;
}

input[type="range"]::-webkit-slider-runnable-track {
  height: 6px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.1);
}

input[type="range"]::-webkit-slider-thumb {
  appearance: none;
  width: 18px;
  height: 18px;
  margin-top: -6px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 0 4px var(--accent-soft);
}

input[type="range"]::-moz-range-track {
  height: 6px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.1);
}

input[type="range"]::-moz-range-thumb {
  width: 18px;
  height: 18px;
  border: 0;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 0 4px var(--accent-soft);
}

select {
  width: 100%;
  min-height: 44px;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: var(--panel-2);
  color: var(--text);
  padding: 0 12px;
  font: inherit;
}

select:focus-visible,
input:focus-visible,
button:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.subpanel {
  margin-top: 16px;
  padding: 14px;
  border-radius: 14px;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid rgba(255, 255, 255, 0.05);
}

.subpanel h2,
.layers-panel h2,
.presets-panel h2 {
  margin: 0 0 12px;
  font-size: 1rem;
  color: var(--text);
}

.note {
  margin: -4px 0 14px;
  color: var(--muted);
  font-size: 0.9rem;
}

.checkbox {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  min-height: 44px;
}

.checkbox input {
  width: 18px;
  height: 18px;
  accent-color: var(--accent);
}

.hidden {
  display: none !important;
}

.preset-buttons {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 12px;
}

.preset-btn {
  appearance: none;
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.03);
  color: var(--text);
  border-radius: 14px;
  padding: 14px 16px;
  font: inherit;
  cursor: pointer;
  transition: border-color 160ms ease, background 160ms ease, transform 120ms ease;
}

.preset-btn:hover {
  border-color: rgba(53, 214, 255, 0.35);
  background: rgba(53, 214, 255, 0.06);
  transform: translateY(-1px);
}

@media (max-width: 640px) {
  body {
    padding: 14px 10px 36px;
  }

  .panel {
    padding: 14px;
  }

  #visualizer {
    height: 180px;
  }
}