:root {
  --background: #19172e;
  --panel-bg: #262356;
  --accent: #7f53ac;
  --accent2: #647dee;
  --button-bg: linear-gradient(90deg, #7f53ac 30%, #647dee 100%);
  --button-selected: #56ec8d;
  --bar-base: linear-gradient(160deg, #ffffff, hsl(249, 80%, 86%) 100%);
  --bar-compare: #f7f779;
  --bar-sorted: #adff2f;
  --bar-pivot: #ff5733;
  --bar-selected: #ffd700;
  --bar-focus: #00bfff;
  --bar-shadow: 0 2px 10px 0 #383b8470;
  --radius: 8px;
  --transition: 0.2s cubic-bezier(.17,.67,.83,.67);
  --font-main: 'Segoe UI', 'Helvetica Neue', Arial, sans-serif;
}

html, body {
  margin: 0;
  padding: 0;
  min-height: 100%;
  font-family: var(--font-main);
  background: var(--background);
  color: #f8fafd;
}

header {
  background: var(--panel-bg);
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 2rem 1rem 1rem 1rem;
  border-bottom: 2px solid #45349a;
}

#logo {
  height: 150px;
  margin: -10px;
  margin-bottom: 0.8rem;
  border-radius: var(--radius);
  box-shadow: var(--bar-shadow);
  background: #fff;
}

h1, h2, h3 {
  text-shadow: 0 1px 2px rgba(0,0,0,0.3);
  font-weight: 700;
}

.subtitle {
  color: #e8ecff;
  font-size: 1.15rem;
  font-weight: 500;
  text-shadow: 0 1px 2px rgba(0,0,0,0.2);
  margin-top: -0.2rem;
  margin-bottom: 0;
  text-align: center;
  max-width: 640px;
  line-height: 1.4;
}

/* Make the three main sections equal size and properly spaced */
main {
  width: 90vw;
  max-width: 1120px;
  margin: auto;
  padding: 1.2rem 0.5rem 0 0.5rem;
  display: grid;
  grid-template-rows: auto auto 1fr auto;
  gap: 1.2rem;
  min-height: 80vh;
}

/* Center all controls in the panel */
#controls-panel {
  background: var(--panel-bg);
  box-shadow: 0 2px 20px #19143a21;
  border-radius: var(--radius);
  padding: 1.5rem 1.2rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1rem;
}

.row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  align-items: center;
  justify-content: center;
}

/* Improved button styling with active states */
button, select {
  background: var(--button-bg);
  border: none;
  color: #fff;
  font-size: 1.05rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  border-radius: var(--radius);
  padding: 0.7em 1.6em;
  cursor: pointer;
  margin: 0 0.3em;
  box-shadow: 0 2px 8px #383b8418;
  transition: all 0.2s ease;
  min-width: 120px;
  text-align: center;
}

/* Button hover effect */
button:not(:disabled):hover,
select:hover {
  filter: brightness(1.15) saturate(1.1);
  transform: translateY(-2px) scale(1.04);
  box-shadow: 0 4px 12px #506ee340;
}

/* Button active/pressed state */
button:active,
select:active {
  background: var(--button-selected);
  transform: translateY(0) scale(0.98);
  box-shadow: 0 1px 4px #383b8430;
}

/* Selected button state (for currently running algorithm) */
button.active,
select.active {
  background: linear-gradient(90deg, #56ec8d 30%, #4ecdc4 100%);
  box-shadow: 0 0 0 2px #56ec8d40, 0 2px 8px #383b8418;
  color: #1a1a2e;
  font-weight: 700;
}

/* Disabled button state */
button:disabled {
  background: #484871;
  color: #d7dcf2;
  cursor: not-allowed;
  opacity: 0.67;
  transform: none;
}

/* Algorithm dropdown specific styling */
#algorithm_select {
  background: var(--button-bg);
  color: #fff;
  border: 2px solid transparent;
  font-size: 1.1rem;
  font-weight: 600;
  padding: 0.65em 1.2em;
  min-width: 160px;
  transition: all 0.3s ease; /* ADDED: Smooth transitions */
}

#algorithm_select:focus {
  border-color: #56ec8d;
  box-shadow: 0 0 0 3px #56ec8d25;
  outline: none;
}

/* ADDED: Enhanced dropdown functionality */
#algorithm_select:not(:disabled) {
  cursor: pointer;
  box-shadow: 0 0 0 1px #56ec8d40;
}

#algorithm_select:not(:disabled):hover {
  filter: brightness(1.1);
  transform: scale(1.02);
}

/* Better option styling */
#algorithm_select option {
  background: var(--panel-bg);
  color: #fff;
  padding: 0.5em;
  font-weight: 500;
}

/* Slider label improvements */
.sliders label {
  font-size: 1.05rem;
  font-weight: 600;
  color: #e8ecff;
  margin-right: 0.6em;
  text-shadow: 0 1px 2px rgba(0,0,0,0.2);
}

input[type=range] {
  appearance: none;
  width: 170px;
  height: 4px;
  margin: 0 10px;
  background: #d5d3fb;
  border-radius: 4px;
  outline: none;
  transition: background 0.16s;
}

input[type=range]:focus {
  background: #98a8ff;
}

input[type=range]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 20px;
  height: 20px;
  background: linear-gradient(90deg,#b66ff6, #647dee80);
  border-radius: 50%;
  box-shadow: 0 2px 5px #19143a44;
  border: 2px solid #6159a8;
  transition: background 0.15s;
  cursor: pointer;
}

input[type=range]:active::-webkit-slider-thumb {
  background: #7f53ac;
}

input[type=range]::-moz-range-thumb {
  width: 20px; height: 20px;
  background: #647dee;
  border-radius: 50%;
}

input[type=range]::-ms-thumb {
  width: 20px; height: 20px;
  background: #7f53ac;
  border-radius: 50%;
}

input[type=range]::-ms-fill-lower, input[type=range]::-ms-fill-upper {
  background: #c5d3fb;
}

input[type=range]:focus::-webkit-slider-thumb {
  box-shadow: 0 0 0 3px #b2e4f355;
}

input[type=range]::-webkit-slider-thumb:hover {
  background: #7f53ac;
}

/* Make algorithm info and legend same visual weight */
#legend {
  background: var(--panel-bg);
  border-radius: var(--radius);
  padding: 1rem 1.2rem;
  box-shadow: 0 2px 10px #19143a26;
  color: #c3c5ea;
  font-size: 0.98rem;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1.5rem;
  flex-wrap: wrap;
}

.legend-bar {
  display: inline-block;
  width: 20px;
  height: 16px;
  border-radius: 4px;
  margin-right: 0.4em;
  vertical-align: middle;
  border: 1px solid rgba(255,255,255,0.2);
}

/* ENHANCED: Visualizer container functionality */
#visualizer-container {
  width: 100%;
  height: 56vh;
  min-height: 300px;
  max-height: 600px; /* ADDED: Prevent excessive growth */
  display: flex;
  justify-content: center;
  align-items: flex-end;
  background: linear-gradient(180deg, #201c42 60%, #32377a 100%);
  border-radius: var(--radius);
  box-shadow: var(--bar-shadow);
  margin-bottom: 1.2em;
  padding: 15px; /* ENHANCED: Consistent padding */
  box-sizing: border-box; /* ADDED: Include padding in width calculation */
}

/* ENHANCED: Flex container functionality */
.flex-container {
  width: 100%;
  max-width: 100%; /* ENHANCED: Use full available width */
  display: flex;
  align-items: flex-end;
  justify-content: center;
  height: 100%;
  min-height: 280px;
  gap: 2px;
  overflow: hidden;
  box-sizing: border-box;
}

/* KEEPING YOUR EXACT BAR STYLING - NO VISUAL CHANGES */
.bar, .flex-item {
  background: var(--bar-base);
  border-radius: 6px 6px 0 0;
  margin: 0px;
  width: 11px;
  min-width: 2px; /* ENHANCED: Better responsiveness for large arrays */
  max-width: 20px; /* ENHANCED: Better responsiveness for small arrays */
  box-shadow: var(--bar-shadow);
  transition:
    height 0.24s var(--transition),
    background 0.18s var(--transition),
    box-shadow 0.18s;
  opacity: 1; /* ADDED: Ensure bars are always visible */
}

/* KEEPING YOUR EXACT BAR STATES - NO VISUAL CHANGES */
.bar[style*="background: #f7f779"], .bar.comparing {
  background: var(--bar-compare) !important;
  box-shadow: 0 0 9px 0 #e7f70955 !important;
}
.bar[style*="background: #adff2f"], .bar.sorted {
  background: var(--bar-sorted) !important;
  box-shadow: 0 2px 16px 0 #a8ff2f24;
}
.bar[style*="background: #ff5733"], .bar.pivot {
  background: var(--bar-pivot) !important;
}
.bar[style*="background: #ffd700"], .bar.selected {
  background: var(--bar-selected) !important;
}
.bar[style*="background: #00bfff"], .bar.focus {
  background: var(--bar-focus) !important;
}

/* ADDED: Support for additional animation colors without changing appearance */
.bar[style*="background: #ff4081"], .bar.moving {
  background: #ff4081 !important;
}

#algo-info {
  background: var(--panel-bg);
  border-radius: var(--radius);
  box-shadow: 0 2px 10px #19143a26;
  padding: 1.5rem 1.2rem;
  font-size: 1.06em;
  text-align: center;
}

#algorithmName {
  margin-top: 0.2em;
  margin-bottom: 0.5em;
  font-size: 1.4em;
  color: #adb8ff;
  text-shadow: 0 1px 3px rgba(0,0,0,0.3);
}

#algorithmDescription {
  color: #e1e4f2;
  margin-top: 0;
  margin-bottom: 0.8em;
  font-size: 1.1em;
  line-height: 1.5;
  font-weight: 500;
}

#complexityList {
  padding-left: 1.2em;
  color: #dadbf6;
  font-size: 1.05em;
  line-height: 1.6;
  list-style: none;
}

#complexityList strong {
  color: #c1e5ff;
  font-weight: 700;
}

/* Footer */
footer {
  text-align: center;
  color: #aaaee6;
  background: none;
  margin: 2em 0 1.4em 0;
  font-size: 1.01em;
}

footer span[aria-label="love"] {
  color: #f82a78;
  font-size: 1.14em;
}

/* ENHANCED: Responsive Controls */
@media (max-width: 768px) {
  .bar, .flex-item {
    width: 8px;
    margin: 0 0.5px;
  }
  
  main {
    width: 99vw;
    padding: 0.5rem 0.3rem;
  }
  
  .row, #controls-panel {
    flex-direction: column;
    align-items: stretch;
    gap: 0.6rem;
  }
  
  button, select {
    width: 100%;
    margin: 0.2em 0 0.2em 0;
    min-width: auto;
  }
  
  .sliders {
    gap: 0;
  }

  /* ADDED: Mobile visualizer optimizations */
  #visualizer-container {
    height: 45vh;
    min-height: 250px;
    padding: 10px;
  }
}

@media (max-width: 480px) {
  .bar, .flex-item {
    width: 6px;
    margin: 0;
  }

  /* ADDED: Small screen optimizations */
  #visualizer-container {
    height: 40vh;
    min-height: 200px;
    padding: 8px;
  }
}

/* Accessibility: visually hidden text for screen readers */
.visually-hidden {
  position: absolute !important; 
  height: 1px; 
  width: 1px; 
  overflow: hidden; 
  clip: rect(1px, 1px, 1px, 1px);
  white-space: nowrap; 
  border: 0; 
  padding: 0; 
  margin: -1px;
}