:root {
  --bg-main: #121212;
  --bg-panel: #1e1e1e;
  --accent: #00e5ff; /* Cyan */
  --accent-dim: #00b8cc;
  --text: #ffffff;
  --text-dim: #888888;
  --border: #333333;
  --knob-bg: #2a2a2a;
  --shadow: 0 10px 30px rgba(0,0,0,0.5);
  --font-display: 'Orbitron', 'Roboto Mono', monospace;
  --font-ui: 'Inter', sans-serif;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  background-color: var(--bg-main);
  color: var(--text);
  font-family: var(--font-ui);
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
}

.container {
  width: 100%;
  max-width: 800px;
  padding: 2rem;
}

.header {
  text-align: center;
  margin-bottom: 2rem;
}

.title {
  font-family: var(--font-display);
  font-size: 2.5rem;
  letter-spacing: 2px;
  text-transform: uppercase;
  background: linear-gradient(to right, #fff, var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: 0.5rem;
}

.subtitle {
  color: var(--text-dim);
  font-size: 0.9rem;
  letter-spacing: 1px;
}

.main {
  background: var(--bg-panel);
  border-radius: 20px;
  padding: 3rem;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
  display: grid;
  grid-template-columns: 1.5fr 1fr;
  gap: 3rem;
  align-items: center;
}

/* Controls Section */
.controls {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.group {
  display: flex;
  flex-direction: column;
  gap: 0.8rem;
}

label {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--text-dim);
  font-weight: 600;
}

/* BPM Display & Controls */
.bpm-row {
  display: flex;
  align-items: center;
  gap: 1rem;
  background: #000;
  padding: 1rem;
  border-radius: 12px;
  border: 1px solid var(--border);
}

#bpm {
  background: transparent;
  border: none;
  color: var(--accent);
  font-family: var(--font-display);
  font-size: 3.5rem;
  width: 140px;
  text-align: center;
}

#bpm:focus {
  outline: none;
  text-shadow: 0 0 20px rgba(0, 229, 255, 0.5);
}

#bpm-slider {
  flex: 1;
  height: 6px;
  -webkit-appearance: none;
  background: #333;
  border-radius: 3px;
  outline: none;
}

#bpm-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 20px;
  height: 20px;
  background: var(--accent);
  border-radius: 50%;
  cursor: pointer;
  box-shadow: 0 0 10px var(--accent);
}

#tap {
  background: var(--knob-bg);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 1rem 1.5rem;
  border-radius: 8px;
  font-weight: bold;
  cursor: pointer;
  transition: all 0.1s;
  text-transform: uppercase;
  letter-spacing: 1px;
}

#tap:active {
  background: var(--accent);
  color: #000;
  transform: scale(0.95);
}

.bpm-actions {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 1rem;
}

.circle-btn {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--knob-bg);
  border: 1px solid var(--border);
  color: var(--text);
  font-size: 1.2rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s;
}

.circle-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.tempo-label {
  text-align: center;
}

.tempo-label span {
  display: block;
  font-size: 0.7rem;
  color: var(--text-dim);
  text-transform: uppercase;
}

#tempo-name {
  font-size: 1.2rem;
  color: var(--text);
  font-weight: 500;
}

/* Settings Grid */
.row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
}

select {
  background: var(--knob-bg);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 0.8rem;
  border-radius: 8px;
  font-size: 1rem;
  cursor: pointer;
}

select:focus {
  outline: none;
  border-color: var(--accent);
}

/* Start/Stop Button */
#start, #stop {
  width: 100%;
  padding: 1.2rem;
  border-radius: 12px;
  font-size: 1.2rem;
  font-weight: bold;
  text-transform: uppercase;
  letter-spacing: 2px;
  cursor: pointer;
  transition: all 0.2s;
  border: none;
}

#start {
  background: var(--accent);
  color: #000;
  box-shadow: 0 0 20px rgba(0, 229, 255, 0.3);
}

#start:hover {
  background: #fff;
  box-shadow: 0 0 30px rgba(255, 255, 255, 0.5);
}

#stop {
  background: #ff3d00;
  color: #fff;
  display: none; /* Hidden by default */
}

/* Visual Section */
.visual {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100%;
  background: #151515;
  border-radius: 16px;
  border: 1px solid var(--border);
  position: relative;
  overflow: hidden;
}

#pulse {
  width: 200px;
  height: 200px;
  border-radius: 50%;
  background: radial-gradient(circle, #222, #111);
  border: 2px solid #333;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: inset 0 0 50px rgba(0,0,0,0.8);
}

#pulse::after {
  content: '';
  position: absolute;
  width: 100%;
  height: 100%;
  border-radius: 50%;
  background: var(--accent);
  opacity: 0;
  transform: scale(0.8);
  transition: transform 0.1s, opacity 0.1s;
}

#pulse.active::after {
  opacity: 0.6;
  transform: scale(1);
  box-shadow: 0 0 50px var(--accent);
}

#bar {
  position: absolute;
  font-family: var(--font-display);
  font-size: 5rem;
  color: rgba(255,255,255,0.1);
  z-index: 2;
}

#bar.active {
  color: #fff;
  text-shadow: 0 0 20px rgba(255,255,255,0.8);
}

/* Toggle Switch */
.switch {
  position: relative;
  display: inline-block;
  width: 50px;
  height: 26px;
}

.switch input {
  opacity: 0;
  width: 0;
  height: 0;
}

.slider {
  position: absolute;
  cursor: pointer;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: #333;
  transition: .4s;
  border-radius: 34px;
}

.slider:before {
  position: absolute;
  content: "";
  height: 18px;
  width: 18px;
  left: 4px;
  bottom: 4px;
  background-color: white;
  transition: .4s;
  border-radius: 50%;
}

input:checked + .slider {
  background-color: var(--accent);
}

input:checked + .slider:before {
  transform: translateX(24px);
}

@media (max-width: 768px) {
  .main {
    grid-template-columns: 1fr;
    padding: 1.5rem;
  }
  
  .visual {
    height: 250px;
  }
  
  #bpm {
    font-size: 2.5rem;
    width: 100px;
  }
}