/* page layout */
body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-start;
  gap: 12px;
  padding: 24px 12px;
  background: #0f1115;
  color: white;
}

/* basic layout */
#mode-controls, #waveform-controls, #action-controls, #adsr-controls, #lfo-controls {
    display: inline-flex;
    gap: 10px;
    padding: 12px;
    margin: 12px;
    border-radius: 12px;
    background: rgba(0,0,0,0.25);
    backdrop-filter: blur(6px);
  }

/* ADSR layout */
#adsr-controls {
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: center;
}

#adsr-controls label {
  display: flex;
  flex-direction: column;
  gap: 6px;
  font: 600 12px/1.2 system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
}

#adsr-controls input[type="number"] {
  width: 120px;
  padding: 8px 10px;
  border-radius: 10px;
  border: 1px solid rgba(255,255,255,0.25);
  background: rgba(255,255,255,0.10);
  color: white;
}
  
/* LFO layout */
#lfo-controls {
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: center;
}

#lfo-controls label {
  display: flex;
  flex-direction: column;
  gap: 6px;
  font: 600 12px/1.2 system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  min-width: 220px;
}

#lfo-controls input[type="range"] {
  width: 220px;
}

#lfo-controls output {
  font: 600 12px/1 system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  opacity: 0.85;
}

/* utility */
.hidden {
  display: none !important;
}

  /* base button style */
  .mode-btn, .wave-btn, .action-btn {
    font: 600 14px/1 system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
    padding: 10px 12px;
    border-radius: 10px;
    border: 1px solid rgba(255,255,255,0.25);
    background: rgba(255,255,255,0.10);
    color: white;
    cursor: pointer;
    transition: transform 120ms ease, background 120ms ease, border-color 120ms ease;
  }
  
  .mode-btn:hover, .wave-btn:hover, .action-btn:hover {
    transform: translateY(-1px);
    border-color: rgba(255,255,255,0.45);
  }
  
  /* highlighted/selected button */
  .mode-btn.active, .wave-btn.active {
    background: #1cac09;
    border-color: #0d5c05;
    color: white;
  }

  /* when additive mode is active, only show sine */
#waveform-controls.additive-only .wave-btn:not([data-wave="sine"]) {
    display: none;
  }