:root {
  /* Color system */
  --color-primary: #4361ee;
  --color-primary-light: #4895ef;
  --color-primary-dark: #3a0ca3;
  --color-secondary: #4cc9f0;
  --color-secondary-light: #72efdd;
  --color-secondary-dark: #3f8efc;
  --color-accent: #f72585;
  --color-accent-light: #ff8fab;
  --color-accent-dark: #b5179e;
  
  --color-neutral-50: #f8fafc;
  --color-neutral-100: #f1f5f9;
  --color-neutral-200: #e2e8f0;
  --color-neutral-300: #cbd5e1;
  --color-neutral-400: #94a3b8;
  --color-neutral-500: #64748b;
  --color-neutral-600: #475569;
  --color-neutral-700: #334155;
  --color-neutral-800: #1e293b;
  --color-neutral-900: #0f172a;
  
  --color-success: #10b981;
  --color-warning: #f59e0b;
  --color-error: #ef4444;
  --color-info: #3b82f6;
  
  /* Spacing system (rem) */
  --space-xxs: 0.25rem;  /* 4px */
  --space-xs: 0.5rem;    /* 8px */
  --space-sm: 0.75rem;   /* 12px */
  --space-md: 1rem;      /* 16px */
  --space-lg: 1.5rem;    /* 24px */
  --space-xl: 2rem;      /* 32px */
  --space-xxl: 3rem;     /* 48px */
  --space-xxxl: 4rem;    /* 64px */
  
  /* Typography (rem) */
  --font-size-xs: 0.75rem;    /* 12px */
  --font-size-sm: 0.875rem;   /* 14px */
  --font-size-md: 1rem;       /* 16px */
  --font-size-lg: 1.125rem;   /* 18px */
  --font-size-xl: 1.25rem;    /* 20px */
  --font-size-xxl: 1.5rem;    /* 24px */
  --font-size-xxxl: 2rem;     /* 32px */
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
  --shadow-inner: inset 0 2px 4px 0 rgba(0, 0, 0, 0.06);
  
  /* Border radius */
  --radius-sm: 0.25rem;  /* 4px */
  --radius-md: 0.5rem;   /* 8px */
  --radius-lg: 0.75rem;  /* 12px */
  --radius-xl: 1rem;     /* 16px */
  --radius-full: 9999px;
  
  /* Transitions */
  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
  
  /* Layout */
  --header-height: 4rem;
  --footer-height: 3rem;
  --sidebar-width: 320px;
  --container-max-width: 1600px;
  
  /* Cluster colors */
  --cluster-color-1: #e41a1c;
  --cluster-color-2: #377eb8;
  --cluster-color-3: #4daf4a;
  --cluster-color-4: #984ea3;
  --cluster-color-5: #ff7f00;
  --cluster-color-6: #ffff33;
  --cluster-color-7: #a65628;
  --cluster-color-8: #f781bf;
  --cluster-color-9: #999999;
  --cluster-color-10: #66c2a5;
}

/* Typography System */
html {
  font-size: 16px;
  line-height: 1.5;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
  font-size: var(--font-size-md);
  color: var(--color-neutral-800);
  background-color: var(--color-neutral-50);
  margin: 0;
  padding: 0;
  min-height: 100vh;
  overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
  margin-top: 0;
  font-weight: 700;
  line-height: 1.2;
  color: var(--color-neutral-900);
}

h1 {
  font-size: var(--font-size-xxxl);
  margin-bottom: var(--space-md);
}

h2 {
  font-size: var(--font-size-xxl);
  margin-bottom: var(--space-sm);
}

h3 {
  font-size: var(--font-size-xl);
  margin-bottom: var(--space-sm);
}

p {
  margin-top: 0;
  margin-bottom: var(--space-md);
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--color-primary-dark);
  text-decoration: underline;
}

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

/* Layout Components */
.app-container {
  display: grid;
  grid-template-rows: auto 1fr auto;
  min-height: 100vh;
  max-width: var(--container-max-width);
  margin: 0 auto;
}

.app-header {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
  color: white;
  padding: var(--space-md) var(--space-lg);
  box-shadow: var(--shadow-md);
}

.header-content {
  max-width: var(--container-max-width);
  margin: 0 auto;
}

.header-description {
  color: rgba(255, 255, 255, 0.9);
  margin: 0;
}

.main-content {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: var(--space-lg);
  padding: var(--space-lg);
}

.visualization-section {
  display: grid;
  grid-template-rows: 1fr auto;
  gap: var(--space-md);
}

.canvas-container {
  position: relative;
  background-color: white;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  overflow: hidden;
  min-height: 400px;
  transition: box-shadow var(--transition-fast);
}

.canvas-container:hover {
  box-shadow: var(--shadow-lg);
}

#visualization-canvas {
  width: 100%;
  height: 100%;
  display: block;
  cursor: grab;
}

#visualization-canvas:active {
  cursor: grabbing;
}

.canvas-controls {
  position: absolute;
  bottom: var(--space-md);
  right: var(--space-md);
  display: flex;
  gap: var(--space-xs);
  z-index: 10;
}

.info-panel {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--space-md);
}

.info-card {
  background: white;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.info-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.card-title {
  margin: 0;
  padding: var(--space-sm) var(--space-md);
  background: linear-gradient(to right, var(--color-secondary-light), var(--color-secondary));
  color: var(--color-neutral-800);
  font-size: var(--font-size-md);
  font-weight: 600;
}

.status-content, .metrics-content {
  padding: var(--space-md);
}

.status-item, .metric-item {
  display: flex;
  justify-content: space-between;
  margin-bottom: var(--space-xs);
  font-size: var(--font-size-sm);
}

.status-label, .metric-label {
  color: var(--color-neutral-600);
  font-weight: 500;
}

.status-value, .metric-value {
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  font-weight: 500;
}

/* Status indicators */
.status-waiting {
  color: var(--color-neutral-500);
}

.status-running {
  color: var(--color-primary);
  animation: pulse 1.5s infinite;
}

.status-converged {
  color: var(--color-success);
}

@keyframes pulse {
  0% { opacity: 1; }
  50% { opacity: 0.6; }
  100% { opacity: 1; }
}

.progress-container {
  padding: 0 var(--space-md) var(--space-md);
}

.progress-label {
  font-size: var(--font-size-xs);
  color: var(--color-neutral-600);
  margin-bottom: var(--space-xxs);
}

.progress-track {
  background-color: var(--color-neutral-200);
  height: 6px;
  border-radius: var(--radius-full);
  overflow: hidden;
}

.progress-bar {
  height: 100%;
  background: linear-gradient(to right, var(--color-primary-light), var(--color-primary));
  border-radius: var(--radius-full);
  transition: width var(--transition-normal);
}

.cluster-stats {
  grid-column: 1 / -1;
}

.cluster-stats-container {
  padding: var(--space-md);
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
  gap: var(--space-md);
}

.empty-state {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100%;
  min-height: 100px;
  color: var(--color-neutral-400);
  font-style: italic;
  text-align: center;
  grid-column: 1 / -1;
}

.cluster-stat-item {
  background-color: var(--color-neutral-50);
  border-radius: var(--radius-md);
  padding: var(--space-sm);
  border: 1px solid var(--color-neutral-200);
  transition: transform var(--transition-fast);
}

.cluster-stat-item:hover {
  transform: translateY(-2px);
}

.cluster-header {
  display: flex;
  align-items: center;
  margin-bottom: var(--space-xs);
}

.cluster-color {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  margin-right: var(--space-xs);
}

.cluster-title {
  font-size: var(--font-size-sm);
  font-weight: 600;
  margin: 0;
}

.cluster-stat {
  font-size: var(--font-size-xs);
  display: flex;
  justify-content: space-between;
  margin-bottom: var(--space-xxs);
}

.cluster-bar {
  height: 4px;
  background-color: var(--color-neutral-200);
  border-radius: var(--radius-full);
  overflow: hidden;
  margin-top: var(--space-xs);
}

.cluster-bar-fill {
  height: 100%;
  border-radius: var(--radius-full);
}

.control-section {
  display: flex;
  flex-direction: column;
}

.control-panel {
  background: white;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  overflow: hidden;
}

.panel-section {
  border-bottom: 1px solid var(--color-neutral-200);
}

.panel-section:last-child {
  border-bottom: none;
}

.section-title {
  padding: var(--space-sm) var(--space-md);
  margin: 0;
  background-color: var(--color-neutral-100);
  font-size: var(--font-size-md);
  font-weight: 600;
  color: var(--color-neutral-700);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: background-color var(--transition-fast);
}

.section-title::after {
  content: "";
  display: inline-block;
  width: 10px;
  height: 10px;
  border-right: 2px solid var(--color-neutral-500);
  border-bottom: 2px solid var(--color-neutral-500);
  transform: rotate(45deg);
  transition: transform var(--transition-fast);
}

.panel-section.collapsed .section-title::after {
  transform: rotate(-45deg);
}

.section-title:hover {
  background-color: var(--color-neutral-200);
}

.section-content {
  padding: var(--space-md);
  transition: max-height var(--transition-normal), opacity var(--transition-normal);
  max-height: 1000px;
  opacity: 1;
  overflow: hidden;
}

.panel-section.collapsed .section-content {
  max-height: 0;
  padding-top: 0;
  padding-bottom: 0;
  opacity: 0;
}

.form-group {
  margin-bottom: var(--space-md);
}

.form-group:last-child {
  margin-bottom: 0;
}

.form-group label {
  display: block;
  margin-bottom: var(--space-xs);
  font-weight: 500;
  color: var(--color-neutral-700);
}

.form-control {
  width: 100%;
  padding: var(--space-xs) var(--space-sm);
  border: 1px solid var(--color-neutral-300);
  border-radius: var(--radius-md);
  font-size: var(--font-size-md);
  color: var(--color-neutral-800);
  background-color: white;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-control:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(67, 97, 238, 0.15);
}

.range-with-value {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.form-range {
  flex: 1;
  -webkit-appearance: none;
  height: 6px;
  background: var(--color-neutral-200);
  border-radius: var(--radius-full);
  outline: none;
}

.form-range::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--color-primary);
  cursor: pointer;
  transition: transform var(--transition-fast), background var(--transition-fast);
}

.form-range::-moz-range-thumb {
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--color-primary);
  cursor: pointer;
  transition: transform var(--transition-fast), background var(--transition-fast);
}

.form-range::-webkit-slider-thumb:hover,
.form-range::-webkit-slider-thumb:active {
  transform: scale(1.2);
  background: var(--color-primary-dark);
}

.form-range::-moz-range-thumb:hover,
.form-range::-moz-range-thumb:active {
  transform: scale(1.2);
  background: var(--color-primary-dark);
}

.invert-range {
  direction: rtl;
}

.range-value {
  min-width: 48px;
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-neutral-700);
  text-align: right;
}

.checkbox-group {
  display: flex;
  align-items: center;
}

.form-checkbox {
  -webkit-appearance: none;
  appearance: none;
  width: 18px;
  height: 18px;
  border: 2px solid var(--color-neutral-400);
  border-radius: var(--radius-sm);
  margin-right: var(--space-xs);
  position: relative;
  cursor: pointer;
  transition: background-color var(--transition-fast), border-color var(--transition-fast);
}

.form-checkbox:checked {
  background-color: var(--color-primary);
  border-color: var(--color-primary);
}

.form-checkbox:checked::after {
  content: "";
  position: absolute;
  top: 3px;
  left: 6px;
  width: 4px;
  height: 8px;
  border: solid white;
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
}

.form-checkbox:focus {
  outline: none;
  box-shadow: 0 0 0 3px rgba(67, 97, 238, 0.15);
}

.checkbox-group label {
  display: inline;
  margin-bottom: 0;
  cursor: pointer;
}

.button-group {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-xs);
}

.simulation-controls {
  margin-bottom: var(--space-md);
}

/* Button Styles */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-xs) var(--space-md);
  font-size: var(--font-size-sm);
  font-weight: 500;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: background-color var(--transition-fast), transform var (--transition-fast), box-shadow var(--transition-fast);
}

.btn:focus {
  outline: none;
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.btn-primary {
  background-color: var(--color-primary);
  color: white;
  box-shadow: var(--shadow-sm);
}

.btn-primary:hover:not(:disabled) {
  background-color: var(--color-primary-dark);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn-primary:active:not(:disabled) {
  transform: translateY(0);
}

.btn-secondary {
  background-color: var(--color-neutral-200);
  color: var(--color-neutral-800);
}

.btn-secondary:hover:not(:disabled) {
  background-color: var(--color-neutral-300);
  transform: translateY(-1px);
}

.btn-secondary:active:not(:disabled) {
  transform: translateY(0);
}

.btn-success {
  background-color: var(--color-success);
  color: white;
  box-shadow: var(--shadow-sm);
}

.btn-success:hover:not(:disabled) {
  background-color: #0da271;
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn-success:active:not(:disabled) {
  transform: translateY(0);
}

.btn-warning {
  background-color: var(--color-warning);
  color: white;
  box-shadow: var(--shadow-sm);
}

.btn-warning:hover:not(:disabled) {
  background-color: #e08e0b;
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn-warning:active:not(:disabled) {
  transform: translateY(0);
}

.btn-danger {
  background-color: var(--color-error);
  color: white;
  box-shadow: var(--shadow-sm);
}

.btn-danger:hover:not(:disabled) {
  background-color: #dc2626;
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn-danger:active:not(:disabled) {
  transform: translateY(0);
}

.btn-icon {
  padding: var(--space-xs);
  border-radius: var(--radius-full);
  background-color: rgba(255, 255, 255, 0.8);
  border: 1px solid var(--color-neutral-200);
}

.btn-icon svg {
  width: 20px;
  height: 20px;
  fill: var(--color-neutral-700);
}

.btn-icon:hover {
  background-color: white;
}

/* Tooltip */
.tooltip-container {
  display: inline-block;
  position: relative;
  margin-left: var(--space-xs);
  vertical-align: middle;
}

.tooltip-trigger {
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background-color: var(--color-neutral-400);
  color: white;
  font-size: var(--font-size-xs);
  border: none;
  cursor: help;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background-color var(--transition-fast);
}

.tooltip-trigger:hover {
  background-color: var(--color-neutral-600);
}

.tooltip-content {
  position: absolute;
  bottom: 100%;
  left: 50%;
  transform: translateX(-50%);
  background-color: var(--color-neutral-800);
  color: white;
  padding: var(--space-sm);
  border-radius: var(--radius-md);
  width: 250px;
  box-shadow: var(--shadow-lg);
  font-size: var(--font-size-xs);
  line-height: 1.4;
  z-index: 100;
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-fast), visibility var(--transition-fast);
  pointer-events: none;
}

.tooltip-content::after {
  content: "";
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%);
  border-width: 5px;
  border-style: solid;
  border-color: var(--color-neutral-800) transparent transparent transparent;
}

.tooltip-content p {
  margin-bottom: var(--space-xs);
}

.tooltip-content p:last-child {
  margin-bottom: 0;
}

.tooltip-container:hover .tooltip-content {
  opacity: 1;
  visibility: visible;
}

/* Notification System */
.notification-container {
  position: fixed;
  top: var(--space-lg);
  right: var(--space-lg);
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  z-index: 1000;
  pointer-events: none;
}

.notification {
  background-color: white;
  border-radius: var(--radius-md);
  padding: var(--space-sm) var(--space-md);
  box-shadow: var(--shadow-lg);
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 300px;
  pointer-events: auto;
  transform: translateX(120%);
  opacity: 0;
  transition: transform var(--transition-normal), opacity var(--transition-normal);
}

.notification.show {
  transform: translateX(0);
  opacity: 1;
}

.notification-icon {
  margin-right: var(--space-xs);
  flex-shrink: 0;
}

.notification-message {
  flex-grow: 1;
  font-size: var(--font-size-sm);
}

.notification-close {
  background: none;
  border: none;
  color: var(--color-neutral-500);
  cursor: pointer;
  padding: 0;
  margin-left: var(--space-xs);
  font-size: var(--font-size-lg);
  line-height: 1;
  transition: color var(--transition-fast);
}

.notification-close:hover {
  color: var(--color-neutral-800);
}

.notification-success {
  border-left: 4px solid var(--color-success);
}

.notification-info {
  border-left: 4px solid var(--color-info);
}

.notification-warning {
  border-left: 4px solid var(--color-warning);
}

.notification-error {
  border-left: 4px solid var(--color-error);
}

/* Footer */
.app-footer {
  background-color: var(--color-neutral-800);
  color: var(--color-neutral-300);
  padding: var(--space-md) var(--space-lg);
  margin-top: var(--space-lg);
}

.footer-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: var(--container-max-width);
  margin: 0 auto;
}

.copyright, .attribution {
  margin: 0;
  font-size: var(--font-size-sm);
}

/* Responsive Design */
@media (max-width: 1200px) {
  .main-content {
    grid-template-columns: 1fr;
    grid-template-rows: auto auto;
  }
  
  .canvas-container {
    height: 500px;
  }
  
  .info-panel {
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  }
}

@media (max-width: 768px) {
  :root {
    --font-size-xxxl: 1.75rem;
    --font-size-xxl: 1.375rem;
  }
  
  .app-header {
    padding: var(--space-md);
  }
  
  .main-content {
    padding: var(--space-md);
    gap: var(--space-md);
  }
  
  .canvas-container {
    height: 400px;
  }
  
  .info-panel {
    grid-template-columns: 1fr;
  }
  
  .cluster-stats-container {
    grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
  }
  
  .button-group {
    flex-direction: column;
  }
  
  .simulation-controls {
    flex-direction: row;
    flex-wrap: wrap;
  }
  
  .simulation-controls .btn {
    flex: 1;
    min-width: 80px;
  }
  
  .footer-content {
    flex-direction: column;
    gap: var(--space-xs);
    text-align: center;
  }
}

@media (max-width: 480px) {
  :root {
    --font-size-xxxl: 1.5rem;
    --font-size-xxl: 1.25rem;
    --font-size-xl: 1.125rem;
  }
  
  .app-header {
    padding: var(--space-sm);
  }
  
  .main-content {
    padding: var(--space-sm);
  }
  
  .canvas-container {
    height: 300px;
  }
  
  .section-content {
    padding: var(--space-sm);
  }
  
  .notification-container {
    top: var(--space-sm);
    right: var(--space-sm);
    left: var(--space-sm);
  }
  
  .notification {
    max-width: 100%;
  }
  
  .btn {
    padding: var(--space-xs) var(--space-sm);
  }
}

/* Focus Styles for Accessibility */
:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: var(--color-neutral-100);
}

::-webkit-scrollbar-thumb {
  background: var(--color-neutral-400);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--color-neutral-500);
}

.input-with-label {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.input-with-label .form-control {
  width: 100px;
  text-align: right;
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
}

.input-label {
  color: var(--color-neutral-600);
  font-size: var(--font-size-sm);
}