/* Modern Panel Method Visualization Styles */

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

:root {
  --primary-color: #2563eb;
  --primary-hover: #1d4ed8;
  --secondary-color: #64748b;
  --danger-color: #dc2626;
  --warning-color: #f59e0b;
  --bg-primary: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-tertiary: #f1f5f9;
  --border-color: #e2e8f0;
  --text-primary: #1e293b;
  --text-secondary: #64748b;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  font-size: 14px;
  line-height: 1.5;
  color: var(--text-primary);
  background: var(--bg-secondary);
  overflow: hidden;
  /* Prevent pull-to-refresh on mobile */
  overscroll-behavior: none;
  /* Enable momentum scrolling on iOS */
  -webkit-overflow-scrolling: touch;
  /* Fix for iOS Safari */
  position: fixed;
  width: 100%;
  height: 100%;
}

/* Prevent body scroll when mobile sidebar is open */
body.mobile-sidebar-open {
  overflow: hidden;
}

.app-container {
  display: flex;
  height: 100vh;
  height: 100dvh; /* Dynamic viewport height for mobile browsers */
  width: 100vw;
  position: relative;
}

/* Sidebar Styles */
.sidebar {
  width: 320px;
  background: var(--bg-primary);
  border-right: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.sidebar-header {
  padding: 1.5rem 1rem 1rem;
  border-bottom: 1px solid var(--border-color);
  background: linear-gradient(135deg, var(--primary-color) 0%, #1e40af 100%);
  color: white;
}

.sidebar-header h2 {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
}

.coefficients-compact {
  font-size: 0.875rem;
  opacity: 0.95;
}

.coef-line {
  margin-top: 0.25rem;
  font-family: 'SF Mono', Monaco, 'Courier New', monospace;
}

/* Kutta Toggle (Omnipresent at top) */
.kutta-toggle-container {
  padding: 1rem;
  background: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);
  border-bottom: 2px solid var(--border-color);
}

.kutta-toggle-label {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.75rem 1rem;
  background: white;
  border: 2px solid var(--border-color);
  border-radius: 0.5rem;
  cursor: pointer;
  transition: all 0.2s ease;
  box-shadow: var(--shadow-sm);
}

.kutta-toggle-label:hover {
  border-color: var(--primary-color);
  box-shadow: var(--shadow-md);
}

.kutta-toggle-label input[type="checkbox"] {
  position: absolute;
  opacity: 0;
  width: 0;
  height: 0;
}

.kutta-text {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 600;
  color: var(--text-primary);
  font-size: 0.95rem;
}

.kutta-icon {
  font-size: 1.25rem;
  transition: transform 0.3s ease;
}

.kutta-toggle-label input[type="checkbox"]:checked ~ .kutta-text .kutta-icon {
  transform: rotate(180deg);
}

.kutta-status {
  padding: 0.25rem 0.75rem;
  border-radius: 0.25rem;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  transition: all 0.2s ease;
}

.kutta-toggle-label input[type="checkbox"]:not(:checked) ~ .kutta-status {
  background: #fee;
  color: #c00;
}

.kutta-toggle-label input[type="checkbox"]:checked ~ .kutta-status {
  background: #efe;
  color: #080;
}

.kutta-toggle-label input[type="checkbox"]:checked ~ .kutta-text {
  color: var(--primary-color);
}

.kutta-help {
  display: block;
  margin-top: 0.5rem;
  font-size: 0.75rem;
  color: var(--text-secondary);
  text-align: center;
}

/* Vertical Tabs */
.vertical-tabs {
  display: flex;
  flex-direction: column;
  padding: 0.5rem;
  border-bottom: 1px solid var(--border-color);
  background: var(--bg-tertiary);
}

.vertical-tab-btn {
  padding: 0.75rem 1rem;
  text-align: left;
  border: none;
  background: transparent;
  color: var(--text-secondary);
  font-weight: 500;
  cursor: pointer;
  border-radius: 0.375rem;
  transition: all 0.15s ease;
  margin-bottom: 0.25rem;
}

.vertical-tab-btn:hover {
  background: var(--bg-primary);
  color: var(--text-primary);
}

.vertical-tab-btn.active {
  background: var(--primary-color);
  color: white;
}

/* Section Content */
.section-content {
  display: none;
  flex: 1;
  overflow-y: auto;
  overflow-x: hidden;
  padding: 1rem;
  /* Enable momentum scrolling on iOS */
  -webkit-overflow-scrolling: touch;
  /* Create a new stacking context for better mobile performance */
  transform: translateZ(0);
}

.section-content.active {
  display: block;
}

.section-content h3 {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.subsection {
  margin-top: 1.5rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border-color);
}

.subsection h4 {
  font-size: 0.875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-secondary);
  margin-bottom: 0.75rem;
}

/* Control Groups */
.control-group {
  margin-bottom: 1rem;
}

.control-group label {
  display: block;
  font-weight: 500;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
}

.control-group input[type="number"],
.control-group select {
  width: 100%;
  padding: 0.5rem;
  border: 1px solid var(--border-color);
  border-radius: 0.375rem;
  font-size: 0.875rem;
  transition: border-color 0.15s ease;
}

.control-group input[type="number"]:focus,
.control-group select:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.input-with-unit {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.input-with-unit input {
  flex: 1;
}

.unit {
  color: var(--text-secondary);
  font-weight: 500;
}

/* Sliders */
.slider {
  width: 100%;
  height: 6px;
  border-radius: 3px;
  background: var(--bg-tertiary);
  outline: none;
  -webkit-appearance: none;
}

.slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--primary-color);
  cursor: pointer;
  transition: all 0.15s ease;
}

.slider::-webkit-slider-thumb:hover {
  background: var(--primary-hover);
  transform: scale(1.1);
}

.slider::-moz-range-thumb {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--primary-color);
  cursor: pointer;
  border: none;
  transition: all 0.15s ease;
}

.slider::-moz-range-thumb:hover {
  background: var(--primary-hover);
  transform: scale(1.1);
}

/* Checkboxes */
.checkbox-group {
  margin-bottom: 0.75rem;
}

.checkbox-label {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  cursor: pointer;
  font-weight: 400;
}

.checkbox-label input[type="checkbox"] {
  width: 18px;
  height: 18px;
  cursor: pointer;
}

/* Radio Groups */
.radio-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  margin-top: 0.5rem;
}

.radio-label {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  cursor: pointer;
  font-weight: 400;
}

.radio-label input[type="radio"] {
  width: 16px;
  height: 16px;
  cursor: pointer;
}

/* Help Text */
.help-text {
  display: block;
  margin-top: 0.25rem;
  font-size: 0.75rem;
  color: var(--text-secondary);
}

.help-text.warning {
  color: var(--warning-color);
}

/* Buttons */
.btn {
  width: 100%;
  padding: 0.5rem 1rem;
  border: none;
  border-radius: 0.375rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.15s ease;
  font-size: 0.875rem;
}

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

.btn-primary:hover {
  background: var(--primary-hover);
}

.btn-secondary {
  background: var(--bg-tertiary);
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}

.btn-secondary:hover {
  background: var(--border-color);
}

.btn-warning {
  background: var(--warning-color);
  color: white;
  margin-bottom: 0.5rem;
}

.btn-warning:hover {
  background: #d97706;
}

.btn-danger {
  background: var(--danger-color);
  color: white;
}

.btn-danger:hover {
  background: #b91c1c;
}

/* Sidebar Footer */
.sidebar-footer {
  padding: 1rem;
  border-top: 1px solid var(--border-color);
}

/* Main Content Area */
.main-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

/* Main Tabs */
.main-tabs {
  display: flex;
  background: var(--bg-primary);
  border-bottom: 2px solid var(--border-color);
  padding: 0 1rem;
}

.main-tab-btn {
  padding: 1rem 1.5rem;
  border: none;
  background: transparent;
  color: var(--text-secondary);
  font-weight: 500;
  cursor: pointer;
  border-bottom: 3px solid transparent;
  transition: all 0.15s ease;
  margin-bottom: -2px;
}

.main-tab-btn:hover {
  color: var(--text-primary);
  background: var(--bg-secondary);
}

.main-tab-btn.active {
  color: var(--primary-color);
  border-bottom-color: var(--primary-color);
}

/* Tab Content */
.tab-content {
  display: none;
  flex: 1;
  overflow: hidden;
}

.tab-content.active {
  display: flex;
  flex-direction: column;
}

/* Visualization Tab */
#flowfield-container {
  flex: 1;
  position: relative;
  background: #ffffff;
  /* Prevent touch events from being blocked */
  touch-action: none;
  overflow: hidden;
}

#flowfield-container canvas {
  width: 100% !important;
  height: 100% !important;
  /* Prevent canvas from blocking touch events on mobile */
  touch-action: none;
}

.badge {
  position: absolute;
  bottom: 1rem;
  right: 1rem;
  padding: 0.5rem 1rem;
  background: rgba(0, 0, 0, 0.7);
  color: white;
  border-radius: 0.375rem;
  font-size: 0.75rem;
  font-weight: 500;
  backdrop-filter: blur(4px);
}

/* Cp Plots Tab */
.cp-plots-container {
  flex: 1;
  padding: 2rem;
  overflow-y: auto;
  overflow-x: hidden;
  -webkit-overflow-scrolling: touch;
  transform: translateZ(0);
}

.cp-plots-container h3 {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: 1.5rem;
}

.cp-plots-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
}

.cp-plot-item h4 {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 1rem;
}

.cp-plot-item canvas {
  width: 100%;
  height: 400px;
  border: 1px solid var(--border-color);
  border-radius: 0.375rem;
}

/* Basics Debugging Tab */
.basics-container {
  display: flex;
  flex: 1;
  overflow: hidden;
}

.basics-controls {
  width: 300px;
  padding: 1rem;
  background: var(--bg-tertiary);
  border-right: 1px solid var(--border-color);
  overflow-y: auto;
  overflow-x: hidden;
  -webkit-overflow-scrolling: touch;
  transform: translateZ(0);
}

.basics-controls h3 {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 1rem;
}

.basics-section {
  margin-bottom: 1.5rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border-color);
}

.basics-section h4 {
  font-size: 0.875rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-secondary);
}

.basics-list {
  font-size: 0.875rem;
  margin-top: 0.5rem;
}

.basics-main {
  flex: 1;
  display: flex;
  flex-direction: column;
  padding: 1rem;
  gap: 1rem;
}

#basics-canvas {
  flex: 1;
  border: 1px solid var(--border-color);
  border-radius: 0.375rem;
  cursor: crosshair;
  background: white;
}

.basics-results {
  max-height: 200px;
  overflow-y: auto;
  overflow-x: hidden;
  padding: 1rem;
  background: var(--bg-tertiary);
  border-radius: 0.375rem;
  -webkit-overflow-scrolling: touch;
  transform: translateZ(0);
}

.basics-results h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

#basics-results {
  font-family: 'SF Mono', Monaco, 'Courier New', monospace;
  font-size: 0.8125rem;
  white-space: pre-wrap;
  color: var(--text-primary);
}

.grid-inputs {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  margin-bottom: 0.75rem;
}

.grid-inputs label {
  font-size: 0.875rem;
}

.grid-inputs input {
  width: 60px;
  padding: 0.25rem 0.5rem;
  border: 1px solid var(--border-color);
  border-radius: 0.25rem;
  font-size: 0.875rem;
}

/* Mobile Toggle Button */
.mobile-sidebar-toggle {
  display: none;
  position: fixed;
  top: 1rem;
  left: 1rem;
  z-index: 1000;
  padding: 0.75rem 1rem;
  background: var(--primary-color);
  color: white;
  border: none;
  border-radius: 0.5rem;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  box-shadow: var(--shadow-lg);
  transition: all 0.2s ease;
}

.mobile-sidebar-toggle:hover {
  background: var(--primary-hover);
  transform: translateY(-2px);
  box-shadow: 0 12px 20px -5px rgba(0, 0, 0, 0.2);
}

.mobile-sidebar-toggle::before {
  content: '☰ ';
  margin-right: 0.25rem;
}

.sidebar.mobile-open .mobile-sidebar-toggle::before {
  content: '✕ ';
}

/* Responsive Design */
@media (max-width: 1024px) {
  .sidebar {
    width: 280px;
  }
  
  .cp-plots-grid {
    grid-template-columns: 1fr;
  }
  
  body {
    font-size: 13px;
  }
}

/* Tablet and Mobile Layout */
@media (max-width: 768px) {
  body {
    font-size: 14px;
    /* Ensure body stays fixed on mobile */
    position: fixed;
    overflow: hidden;
  }

  .mobile-sidebar-toggle {
    display: block;
  }
  
  .app-container {
    flex-direction: row;
    position: relative;
    /* Use dvh for better mobile browser support */
    height: 100dvh;
    overflow: hidden;
  }
  
  /* Sidebar becomes an overlay on mobile */
  .sidebar {
    position: fixed;
    top: 0;
    left: 0;
    width: 85%;
    max-width: 320px;
    height: 100vh;
    height: 100dvh;
    transform: translateX(-100%);
    transition: transform 0.3s ease;
    z-index: 999;
    box-shadow: var(--shadow-lg);
    overflow-y: auto;
    overflow-x: hidden;
    -webkit-overflow-scrolling: touch;
    /* Hardware acceleration for smoother animation */
    will-change: transform;
  }
  
  .sidebar.mobile-open {
    transform: translateX(0);
  }
  
  /* Overlay backdrop when sidebar is open */
  .sidebar::after {
    content: '';
    position: fixed;
    top: 0;
    left: 100%;
    width: 100vw;
    height: 100vh;
    height: 100dvh;
    background: rgba(0, 0, 0, 0.5);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease;
  }
  
  .sidebar.mobile-open::after {
    opacity: 1;
    pointer-events: auto;
  }
  
  /* Main content takes full width */
  .main-content {
    width: 100%;
    flex: 1;
    overflow: hidden;
    position: relative;
  }
  
  /* Main tabs scroll horizontally on small screens */
  .main-tabs {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    padding: 0 0.5rem;
    flex-shrink: 0;
  }
  
  .main-tab-btn {
    padding: 0.75rem 1rem;
    font-size: 0.875rem;
    white-space: nowrap;
  }
  
  /* Tab content must handle its own scrolling */
  .tab-content {
    overflow: hidden;
    position: relative;
  }
  
  .tab-content.active {
    display: flex;
    flex-direction: column;
    overflow: hidden;
  }
  
  /* Flowfield container - canvas interaction area */
  #flowfield-container {
    overflow: hidden;
    /* Allow pan/zoom gestures */
    touch-action: none;
    position: relative;
  }
  
  /* Adjust badge position for mobile */
  .badge {
    bottom: 0.5rem;
    right: 0.5rem;
    padding: 0.375rem 0.75rem;
    font-size: 0.625rem;
  }
  
  /* Basics tab mobile layout */
  .basics-container {
    flex-direction: column;
    overflow: hidden;
  }
  
  .basics-controls {
    width: 100%;
    max-height: 40vh;
    border-right: none;
    border-bottom: 1px solid var(--border-color);
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
    flex-shrink: 0;
  }
  
  .basics-main {
    padding: 0.75rem;
    flex: 1;
    overflow: hidden;
    display: flex;
    flex-direction: column;
  }
  
  #basics-canvas {
    min-height: 300px;
    flex: 1;
  }
  
  /* Cp plots stack on mobile and scroll properly */
  .cp-plots-container {
    padding: 1rem;
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
  }
  
  .cp-plots-container h3 {
    font-size: 1.25rem;
  }
  
  .cp-plot-item canvas {
    height: 250px;
  }
  
  /* Sidebar sections more compact on mobile */
  .sidebar-header {
    padding: 1rem 0.75rem 0.75rem;
    flex-shrink: 0;
  }
  
  .sidebar-header h2 {
    font-size: 1.25rem;
  }
  
  .section-content {
    padding: 0.75rem;
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
  }
  
  .section-content h3 {
    font-size: 1rem;
  }
  
  .kutta-toggle-container {
    padding: 0.75rem;
    flex-shrink: 0;
  }
  
  .vertical-tabs {
    padding: 0.375rem;
    flex-shrink: 0;
  }
  
  .vertical-tab-btn {
    padding: 0.625rem 0.75rem;
    font-size: 0.875rem;
  }
  
  /* Control groups more compact */
  .control-group {
    margin-bottom: 0.875rem;
  }
  
  .subsection {
    margin-top: 1.25rem;
    padding-top: 0.875rem;
  }
  
  /* Buttons more touch-friendly */
  .btn {
    padding: 0.625rem 1rem;
    font-size: 0.875rem;
    /* Prevent zoom on button tap in iOS */
    touch-action: manipulation;
  }
  
  /* Prevent zoom on input focus in iOS */
  input, select, textarea {
    font-size: 16px !important;
    touch-action: manipulation;
  }
}

/* Small phone optimization */
@media (max-width: 480px) {
  .sidebar {
    width: 90%;
    max-width: none;
  }
  
  .mobile-sidebar-toggle {
    padding: 0.625rem 0.875rem;
    font-size: 0.875rem;
    top: 0.5rem;
    left: 0.5rem;
  }
  
  .sidebar-header h2 {
    font-size: 1.125rem;
  }
  
  .coefficients-compact {
    font-size: 0.75rem;
  }
  
  .main-tab-btn {
    padding: 0.625rem 0.875rem;
    font-size: 0.8125rem;
  }
  
  /* Make radio and checkbox labels stack better */
  .radio-group {
    gap: 0.625rem;
  }
  
  .radio-label,
  .checkbox-label {
    font-size: 0.875rem;
  }
  
  /* Optimize grid inputs for small screens */
  .grid-inputs input {
    width: 50px;
    font-size: 0.8125rem;
  }
  
  /* Touch-friendly sliders */
  .slider::-webkit-slider-thumb {
    width: 22px;
    height: 22px;
  }
  
  .slider::-moz-range-thumb {
    width: 22px;
    height: 22px;
  }
}

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

::-webkit-scrollbar-track {
  background: var(--bg-tertiary);
}

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

::-webkit-scrollbar-thumb:hover {
  background: var(--text-secondary);
}