:root {
  --bg-darkest: #0a0e1a;
  --bg-dark: #111827;
  --bg-medium: #1a2035;
  
  --surface-light: rgba(255, 255, 255, 0.03);
  --surface-medium: rgba(255, 255, 255, 0.05);
  --surface-hover: rgba(255, 255, 255, 0.08);
  
  --accent-primary: #00d4ff;
  --accent-primary-glow: rgba(0, 212, 255, 0.15);
  --accent-primary-hover: #33ddff;
  
  --text-primary: #e2e8f0;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  
  /* Category Colors */
  --cat-steel: #4A90D9;
  --cat-aluminum: #50C8C6;
  --cat-copper: #E8833A;
  --cat-titanium: #9B59B6;
  --cat-polymer: #2ECC71;
  --cat-ceramic: #E74C3C;
  --cat-superalloy: #F39C12;
  --cat-composite: #E05555;
  --cat-magnesium: #5DADE2;
  --cat-castiron: #7F8C8D;
  
  --border-radius-card: 12px;
  --border-radius-element: 8px;
  
  --glass-border: 1px solid rgba(255, 255, 255, 0.05);
  --glass-border-light: 1px solid rgba(255, 255, 255, 0.1);
  --glass-filter: blur(20px);
  
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --header-height: 70px;
  --sidebar-width: 280px;
}

.hidden {
  display: none !important;
}

[data-theme="light"] {
  --bg-darkest: #f1f5f9;
  --bg-dark: #ffffff;
  --bg-medium: #e2e8f0;
  
  --surface-light: rgba(0, 0, 0, 0.03);
  --surface-medium: rgba(0, 0, 0, 0.06);
  --surface-hover: rgba(0, 0, 0, 0.09);
  
  --accent-primary: #0284c7;
  --accent-primary-glow: rgba(2, 132, 199, 0.15);
  --accent-primary-hover: #0369a1;
  
  --text-primary: #0f172a;
  --text-secondary: #334155;
  --text-muted: #64748b;
  
  --glass-border: 1px solid rgba(0, 0, 0, 0.1);
  --glass-border-light: 1px solid rgba(0, 0, 0, 0.15);
}

/* Navigation */
.top-nav {
  background: var(--bg-dark);
  border-bottom: var(--glass-border-light);
  height: 40px;
  position: sticky;
  top: 0;
  z-index: 200;
}
.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 2rem;
  height: 100%;
}
.nav-logo { font-weight: 700; color: var(--text-primary); text-decoration: none; font-size: 1rem; }
.nav-links { display: flex; list-style: none; gap: 1.5rem; margin: 0; padding: 0; }
.nav-links a { color: var(--text-secondary); text-decoration: none; font-size: 0.85rem; transition: var(--transition); }
.nav-links a:hover, .nav-links a.active { color: var(--accent-primary); }
.nav-lang a { color: var(--text-primary); text-decoration: none; font-size: 0.85rem; }

/* Static Page Content */
.static-page { padding-top: 0; background: var(--bg-darkest); }
.page-content { max-width: 1000px; margin: 0 auto; padding: 2rem; }
.glass-card.page-card { background: var(--surface-medium); padding: 3rem; border-radius: var(--border-radius-card); border: var(--glass-border); }
.glass-card.page-card h1, .glass-card.page-card h2 { margin-bottom: 1rem; margin-top: 1.5rem; color: var(--text-primary); }
.glass-card.page-card h1 { margin-top: 0; font-size: 2rem; color: var(--accent-primary); }
.glass-card.page-card p, .glass-card.page-card li { color: var(--text-secondary); margin-bottom: 1rem; line-height: 1.6; }
.glass-card.page-card ul { padding-left: 1.5rem; margin-bottom: 1rem; }

/* Unit Dropdown */
.unit-dropdown-trigger {
  background: var(--surface-medium);
  border: var(--glass-border);
  color: var(--text-primary);
  padding: 0.4rem 0.8rem;
  border-radius: 4px;
  font-size: 0.85rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  transition: var(--transition);
}
.unit-dropdown-trigger:hover {
  background: var(--surface-hover);
}
.unit-dropdown-options {
  background: var(--bg-darkest);
  border: var(--glass-border);
  border-radius: 4px;
  box-shadow: 0 4px 12px rgba(0,0,0,0.3);
}
.unit-option {
  padding: 0.6rem 0.8rem;
  font-size: 0.85rem;
  cursor: pointer;
  border-bottom: var(--glass-border);
  transition: var(--transition);
  color: var(--text-primary);
}
.unit-option:hover {
  background: var(--surface-hover);
}

/* Reset & Global Styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Inter', sans-serif;
  background-color: var(--bg-darkest);
  background-image: 
    radial-gradient(circle at 15% 50%, rgba(0, 212, 255, 0.03) 0%, transparent 25%),
    radial-gradient(circle at 85% 30%, rgba(74, 144, 217, 0.03) 0%, transparent 25%);
  color: var(--text-primary);
  line-height: 1.5;
  min-height: 100vh;
  overflow-x: hidden;
}

/* Scrollbar */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}
::-webkit-scrollbar-track {
  background: var(--bg-darkest);
}
::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.1);
  border-radius: 10px;
}
::-webkit-scrollbar-thumb:hover {
  background: rgba(255, 255, 255, 0.2);
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-weight: 600;
  color: #fff;
  letter-spacing: -0.02em;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  outline: none;
}

/* Header */
#app-header {
  position: sticky;
  top: 40px;
  left: 0;
  right: 0;
  height: var(--header-height);
  background: rgba(17, 24, 39, 0.8);
  backdrop-filter: var(--glass-filter);
  -webkit-backdrop-filter: var(--glass-filter);
  border-bottom: var(--glass-border);
  z-index: 100;
}

.header-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  padding: 0 2rem;
  max-width: 1600px;
  margin: 0 auto;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.logo-icon {
  font-size: 1.75rem;
}

.logo-text h1 {
  font-size: 1.25rem;
  font-weight: 700;
  background: linear-gradient(135deg, #fff 0%, var(--accent-primary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  line-height: 1.2;
}

.logo-subtitle {
  font-size: 0.7rem;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* Search */
.search-wrapper {
  flex: 1;
  max-width: 500px;
  position: relative;
  margin: 0 2rem;
}

.search-icon {
  position: absolute;
  left: 1rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  font-size: 1rem;
  pointer-events: none;
}

#search-input {
  width: 100%;
  padding: 0.75rem 1rem 0.75rem 2.5rem;
  background: var(--surface-light);
  border: var(--glass-border);
  border-radius: 24px;
  color: var(--text-primary);
  font-family: inherit;
  font-size: 0.9rem;
  transition: var(--transition);
}

#search-input:focus {
  outline: none;
  background: var(--surface-medium);
  border-color: rgba(0, 212, 255, 0.3);
  box-shadow: 0 0 0 3px rgba(0, 212, 255, 0.1);
}

#search-input::placeholder {
  color: var(--text-muted);
}

/* Buttons */
.header-actions {
  display: flex;
  gap: 1rem;
  align-items: center;
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent-primary) 0%, #0099cc 100%);
  color: #000;
  font-weight: 600;
  padding: 0.6rem 1.2rem;
  border-radius: var(--border-radius-element);
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  transition: var(--transition);
  font-size: 0.85rem;
}

.btn-primary:hover:not(:disabled) {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px var(--accent-primary-glow);
  background: linear-gradient(135deg, var(--accent-primary-hover) 0%, #00aadd 100%);
}

.btn-primary:disabled {
  background: var(--surface-medium);
  color: var(--text-muted);
  cursor: not-allowed;
  opacity: 0.7;
}

.btn-secondary {
  background: var(--surface-medium);
  color: var(--text-primary);
  font-weight: 500;
  padding: 0.6rem 1.2rem;
  border: var(--glass-border);
  border-radius: var(--border-radius-element);
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  transition: var(--transition);
  font-size: 0.85rem;
}

.btn-secondary:hover {
  background: var(--surface-hover);
  border-color: rgba(255, 255, 255, 0.15);
  transform: translateY(-2px);
}

.btn-text {
  background: transparent;
  color: var(--text-secondary);
  font-size: 0.85rem;
  padding: 0.5rem;
  transition: var(--transition);
  width: 100%;
  text-align: left;
  border-radius: var(--border-radius-element);
}

.btn-text:hover {
  color: var(--text-primary);
  background: var(--surface-light);
}

/* App Layout */
#app-body {
  display: flex;
  min-height: 100vh;
}

/* Sidebar */
#sidebar {
  width: var(--sidebar-width);
  position: sticky;
  top: calc(var(--header-height) + 40px);
  height: calc(100vh - var(--header-height) - 40px);
  flex-shrink: 0;
  background: var(--bg-dark);
  border-right: var(--glass-border);
  padding: 1.5rem;
  overflow-y: auto;
  overflow-x: hidden;
  white-space: nowrap;
  display: flex;
  flex-direction: column;
  gap: 2rem;
  transition: width 0.4s cubic-bezier(0.2, 0.8, 0.2, 1), padding 0.4s cubic-bezier(0.2, 0.8, 0.2, 1);
}

#sidebar-content {
  transition: opacity 0.3s ease;
  opacity: 1;
}

.sidebar-title {
  transition: opacity 0.3s ease;
  opacity: 1;
}





.filter-section {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.filter-title {
  font-size: 0.85rem;
  text-transform: uppercase;
  color: var(--text-muted);
  letter-spacing: 0.05em;
  padding-bottom: 0.5rem;
  border-bottom: var(--glass-border);
}

/* Filter Chips */
#category-filters {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.filter-chip {
  background: var(--surface-medium);
  border: var(--glass-border);
  color: var(--text-secondary);
  padding: 0.4rem 0.8rem;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
  user-select: none;
}

.filter-chip:hover {
  background: var(--surface-hover);
  color: var(--text-primary);
}

.filter-chip.active {
  background: var(--surface-light);
  color: #fff;
  border-color: rgba(255,255,255,0.2);
}

/* Specific Category Active Colors */
.filter-chip[data-cat="steel"].active { background: rgba(74, 144, 217, 0.2); border-color: var(--cat-steel); color: var(--cat-steel); }
.filter-chip[data-cat="titanium"].active { background: rgba(155, 89, 182, 0.2); border-color: var(--cat-titanium); color: var(--cat-titanium); }
.filter-chip[data-cat="polymer"].active { background: rgba(46, 204, 113, 0.2); border-color: var(--cat-polymer); color: var(--cat-polymer); }
.filter-chip[data-cat="ceramic"].active { background: rgba(231, 76, 60, 0.2); border-color: var(--cat-ceramic); color: var(--cat-ceramic); }
.filter-chip[data-cat="superalloy"].active { background: rgba(243, 156, 18, 0.2); border-color: var(--cat-superalloy); color: var(--cat-superalloy); }
.filter-chip[data-cat="composite"].active { background: rgba(224, 85, 85, 0.2); border-color: var(--cat-composite); color: var(--cat-composite); }
.filter-chip[data-cat="magnesium"].active { background: rgba(93, 173, 226, 0.2); border-color: var(--cat-magnesium); color: var(--cat-magnesium); }
.filter-chip[data-cat="castiron"].active { background: rgba(127, 140, 141, 0.2); border-color: var(--cat-castiron); color: var(--cat-castiron); }
.filter-chip[data-cat="ceramic"].active { background: rgba(231, 76, 60, 0.2); border-color: var(--cat-ceramic); color: var(--cat-ceramic); }

/* Main Content */
#main-content {
  flex: 1;
  padding: 2rem;
  min-width: 0;
}

/* Stats Bar */
#stats-bar {
  display: flex;
  gap: 1.5rem;
  margin-bottom: 2rem;
  flex-wrap: wrap;
}

.stat-card {
  flex: 1;
  min-width: 200px;
  background: var(--surface-medium);
  border: var(--glass-border);
  border-radius: var(--border-radius-card);
  padding: 1.25rem;
  display: flex;
  align-items: center;
  gap: 1rem;
  transition: var(--transition);
}

.stat-card:hover {
  background: var(--surface-hover);
  border-color: rgba(255, 255, 255, 0.1);
  transform: translateY(-2px);
}

.stat-icon {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.05);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
}

.stat-details {
  display: flex;
  flex-direction: column;
}

.stat-value {
  font-size: 1.5rem;
  font-weight: 700;
  color: #fff;
  line-height: 1.1;
}

.stat-label {
  font-size: 0.8rem;
  color: var(--text-secondary);
  margin-top: 0.25rem;
}

#results-info {
  margin-bottom: 1.5rem;
  font-size: 0.9rem;
  color: var(--text-secondary);
}

/* Materials Grid */
#materials-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 1.5rem;
}

/* Material Card */
.material-card {
  background: var(--surface-light);
  border-radius: var(--border-radius-card);
  border: var(--glass-border);
  padding: 1.5rem;
  position: relative;
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  gap: 1rem;
  cursor: pointer;
  border-left: 4px solid var(--text-muted); /* Fallback */
  animation: fadeIn 0.5s ease backwards;
}

.material-card:hover {
  transform: translateY(-4px);
  background: var(--surface-medium);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.2), 0 4px 12px rgba(255,255,255,0.02);
  border-color: rgba(255, 255, 255, 0.1);
}

/* Example category borders */
.material-card[data-cat="steel"] { border-left-color: var(--cat-steel); }
.material-card[data-cat="steel"]:hover { box-shadow: 0 8px 32px rgba(74, 144, 217, 0.15); }

.material-card[data-cat="aluminum"] { border-left-color: var(--cat-aluminum); }
.material-card[data-cat="aluminum"]:hover { box-shadow: 0 8px 32px rgba(80, 200, 198, 0.15); }

.material-card[data-cat="copper"] { border-left-color: var(--cat-copper); }
.material-card[data-cat="copper"]:hover { box-shadow: 0 8px 32px rgba(232, 131, 58, 0.15); }

.material-card.selected {
  border: 1px solid var(--accent-primary);
  border-left: 4px solid var(--accent-primary);
  box-shadow: 0 0 15px var(--accent-primary-glow);
  background: rgba(0, 212, 255, 0.05);
}

.card-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
}

.material-name {
  font-size: 1.1rem;
  font-weight: 600;
  color: #fff;
  margin-bottom: 0.25rem;
}

.material-code {
  font-size: 0.8rem;
  color: var(--text-muted);
  font-family: monospace;
}

/* Checkbox for Compare */
.compare-checkbox {
  appearance: none;
  width: 20px;
  height: 20px;
  border: 2px solid var(--text-muted);
  border-radius: 4px;
  background: transparent;
  cursor: pointer;
  position: relative;
  transition: var(--transition);
}

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

.compare-checkbox:checked::after {
  content: '✓';
  position: absolute;
  color: #000;
  font-size: 12px;
  font-weight: bold;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}

.compare-checkbox:hover {
  border-color: var(--text-secondary);
}

/* Category Badge */
.category-badge {
  display: inline-block;
  padding: 0.2rem 0.6rem;
  border-radius: 12px;
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  background: rgba(255,255,255,0.1);
}

.material-card[data-cat="steel"] .category-badge { color: var(--cat-steel); background: rgba(74, 144, 217, 0.1); }
.material-card[data-cat="aluminum"] .category-badge { color: var(--cat-aluminum); background: rgba(80, 200, 198, 0.1); }
.material-card[data-cat="copper"] .category-badge { color: var(--cat-copper); background: rgba(232, 131, 58, 0.1); }
.material-card[data-cat="titanium"] .category-badge { color: var(--cat-titanium); background: rgba(155, 89, 182, 0.1); }
.material-card[data-cat="polymer"] .category-badge { color: var(--cat-polymer); background: rgba(46, 204, 113, 0.1); }
.material-card[data-cat="ceramic"] .category-badge { color: var(--cat-ceramic); background: rgba(231, 76, 60, 0.1); }
.material-card[data-cat="superalloy"] .category-badge { color: var(--cat-superalloy); background: rgba(243, 156, 18, 0.1); }
.material-card[data-cat="composite"] .category-badge { color: var(--cat-composite); background: rgba(224, 85, 85, 0.1); }
.material-card[data-cat="magnesium"] .category-badge { color: var(--cat-magnesium); background: rgba(93, 173, 226, 0.1); }
.material-card[data-cat="castiron"] .category-badge { color: var(--cat-castiron); background: rgba(127, 140, 141, 0.1); }

.material-card[data-cat="titanium"] { border-left-color: var(--cat-titanium); }
.material-card[data-cat="titanium"]:hover { box-shadow: 0 8px 32px rgba(155, 89, 182, 0.15); }
.material-card[data-cat="polymer"] { border-left-color: var(--cat-polymer); }
.material-card[data-cat="polymer"]:hover { box-shadow: 0 8px 32px rgba(46, 204, 113, 0.15); }
.material-card[data-cat="ceramic"] { border-left-color: var(--cat-ceramic); }
.material-card[data-cat="ceramic"]:hover { box-shadow: 0 8px 32px rgba(231, 76, 60, 0.15); }
.material-card[data-cat="superalloy"] { border-left-color: var(--cat-superalloy); }
.material-card[data-cat="superalloy"]:hover { box-shadow: 0 8px 32px rgba(243, 156, 18, 0.15); }
.material-card[data-cat="composite"] { border-left-color: var(--cat-composite); }
.material-card[data-cat="composite"]:hover { box-shadow: 0 8px 32px rgba(224, 85, 85, 0.15); }
.material-card[data-cat="magnesium"] { border-left-color: var(--cat-magnesium); }
.material-card[data-cat="magnesium"]:hover { box-shadow: 0 8px 32px rgba(93, 173, 226, 0.15); }
.material-card[data-cat="castiron"] { border-left-color: var(--cat-castiron); }
.material-card[data-cat="castiron"]:hover { box-shadow: 0 8px 32px rgba(127, 140, 141, 0.15); }

/* Category badge in modal context */
.category-badge.steel { color: var(--cat-steel); background: rgba(74, 144, 217, 0.15); }
.category-badge.aluminum { color: var(--cat-aluminum); background: rgba(80, 200, 198, 0.15); }
.category-badge.copper { color: var(--cat-copper); background: rgba(232, 131, 58, 0.15); }
.category-badge.titanium { color: var(--cat-titanium); background: rgba(155, 89, 182, 0.15); }
.category-badge.polymer { color: var(--cat-polymer); background: rgba(46, 204, 113, 0.15); }
.category-badge.ceramic { color: var(--cat-ceramic); background: rgba(231, 76, 60, 0.15); }
.category-badge.superalloy { color: var(--cat-superalloy); background: rgba(243, 156, 18, 0.15); }
.category-badge.composite { color: var(--cat-composite); background: rgba(224, 85, 85, 0.15); }
.category-badge.magnesium { color: var(--cat-magnesium); background: rgba(93, 173, 226, 0.15); }
.category-badge.castiron { color: var(--cat-castiron); background: rgba(127, 140, 141, 0.15); }

/* Filter chip for superalloy */
.filter-chip[data-cat="superalloy"].active { background: rgba(243, 156, 18, 0.2); border-color: var(--cat-superalloy); color: var(--cat-superalloy); }

/* Quick Properties Grid */
.quick-props {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
  margin-top: 0.5rem;
}

.quick-prop {
  display: flex;
  flex-direction: column;
}

.prop-label {
  font-size: 0.7rem;
  color: var(--text-muted);
  margin-bottom: 0.1rem;
}

.prop-value {
  font-size: 0.85rem;
  color: var(--text-primary);
  font-weight: 500;
}

/* Modal Overlays */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background: rgba(0, 0, 0, 0.7);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s ease, visibility 0.3s ease;
}

.modal-overlay.active {
  opacity: 1;
  visibility: visible;
}

.modal-content, .compare-content, .ashby-content {
  background: var(--bg-dark);
  border: var(--glass-border-light);
  border-radius: var(--border-radius-card);
  padding: 2rem;
  position: relative;
  max-height: 90vh;
  overflow-y: auto;
  box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
  transform: scale(0.95) translateY(20px);
  transition: transform 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.modal-overlay.active > div {
  transform: scale(1) translateY(0);
}

.modal-content { max-width: 900px; width: 90%; }
.compare-content { max-width: 1100px; width: 95%; }
.ashby-content { max-width: 1000px; width: 95%; }

.modal-close {
  position: absolute;
  top: 1.5rem;
  right: 1.5rem;
  background: rgba(255,255,255,0.05);
  border: none;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  color: var(--text-secondary);
  font-size: 1.2rem;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: var(--transition);
}

.modal-close:hover {
  background: rgba(255,255,255,0.1);
  color: #fff;
  transform: rotate(90deg);
}

/* Modal Internal Layouts */
#modal-body {
  display: grid;
  grid-template-columns: 1fr 350px;
  gap: 2rem;
  margin: 1.5rem 0;
}

/* Property Groups */
.property-group {
  margin-bottom: 1.5rem;
  background: var(--surface-light);
  border-radius: var(--border-radius-element);
  border: var(--glass-border);
  overflow: hidden;
}

.property-group h4 {
  background: rgba(0,0,0,0.2);
  padding: 0.75rem 1rem;
  font-size: 0.9rem;
  color: var(--text-secondary);
  border-bottom: var(--glass-border);
}

.property-row {
  display: flex;
  justify-content: space-between;
  padding: 0.75rem 1rem;
  border-bottom: 1px solid rgba(255,255,255,0.02);
  font-size: 0.85rem;
}

.property-row:last-child {
  border-bottom: none;
}

.property-row span:first-child {
  color: var(--text-secondary);
}

.property-row span:last-child {
  color: var(--text-primary);
  font-weight: 500;
}

/* Modal Chart Container */
#modal-chart-container, #compare-chart-container {
  background: var(--surface-light);
  border: var(--glass-border);
  border-radius: var(--border-radius-element);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  align-items: center;
}

#modal-chart-container h3, #compare-chart-container h3 {
  width: 100%;
  margin-bottom: 1rem;
  font-size: 1rem;
}

/* Similar Materials */
#modal-similar {
  margin-top: 2rem;
}

.similar-grid {
  display: flex;
  gap: 1rem;
  overflow-x: auto;
  padding-bottom: 1rem;
}

/* Compare Cards */
.panel-title {
  font-size: 1.5rem;
  margin-bottom: 1.5rem;
  padding-bottom: 1rem;
  border-bottom: var(--glass-border);
}

#compare-cards {
  display: flex;
  gap: 1rem;
  margin-bottom: 2rem;
}

.compare-card-mini {
  flex: 1;
  background: var(--surface-light);
  border: var(--glass-border);
  border-radius: var(--border-radius-element);
  padding: 1rem;
  position: relative;
}

/* Recommendations */
#compare-recommendations {
  margin-top: 2rem;
}

#recommendations-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1rem;
  margin-top: 1rem;
}

.recommendation-card {
  background: linear-gradient(145deg, var(--surface-light), var(--surface-medium));
  border: var(--glass-border-light);
  border-radius: var(--border-radius-element);
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  transition: var(--transition);
}

.recommendation-card:hover {
  border-color: rgba(0, 212, 255, 0.3);
  box-shadow: 0 4px 15px rgba(0, 212, 255, 0.05);
  transform: translateY(-2px);
}

.recommendation-card .r-icon {
  font-size: 1.5rem;
  margin-bottom: 0.25rem;
}

.recommendation-card .r-content h5 {
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 0.35rem;
}

.recommendation-card .r-winner {
  font-size: 0.85rem;
  color: var(--accent-primary);
  margin-bottom: 0.35rem;
}

.recommendation-card .r-reason {
  font-size: 0.8rem;
  color: var(--text-primary);
  margin-bottom: 0.25rem;
}

.recommendation-card .r-desc {
  font-size: 0.75rem;
  color: var(--text-muted);
  line-height: 1.4;
}

/* Ashby Diagram Controls */
.ashby-controls {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  margin-bottom: 1.5rem;
  background: var(--surface-light);
  padding: 1rem;
  border-radius: var(--border-radius-element);
  border: var(--glass-border);
}

.select-group {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.select-group label {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

select {
  width: 100%;
  padding: 0.8rem 1rem;
  background-color: var(--surface-light);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--border-radius-element);
  color: #fff;
  font-family: inherit;
  font-size: 0.95rem;
  transition: var(--transition);
  appearance: none;
  background-image: url("data:image/svg+xml;charset=utf-8,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' fill='%2394a3b8' viewBox='0 0 16 16'%3E%3Cpath d='M7.247 11.14 2.451 5.658C1.885 5.013 2.345 4 3.204 4h9.592a1 1 0 0 1 .753 1.659l-4.796 5.48a1 1 0 0 1-1.506 0z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 1rem center;
  background-size: 12px;
}

select:hover {
  background-color: rgba(255,255,255,0.05);
  border-color: rgba(255,255,255,0.3);
}

select:focus {
  outline: none;
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 3px var(--accent-primary-glow);
}

select option {
  background-color: var(--bg-darkest);
  color: var(--text-primary);
  padding: 0.5rem;
}

/* Blog Cards */
.blog-card {
  position: relative;
  overflow: hidden;
}

.blog-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 0;
  background: linear-gradient(135deg, rgba(255,255,255,0.05) 0%, transparent 100%);
  opacity: 0;
  transition: opacity 0.3s ease;
}

.blog-card:hover {
  transform: translateY(-5px) !important;
  border-color: rgba(0, 212, 255, 0.3);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5), 0 0 20px rgba(0, 212, 255, 0.1);
}

.blog-card:hover::before {
  opacity: 1;
}

.vs-badge {
  background: var(--surface-hover);
  color: var(--text-muted);
  padding: 0.2rem 0.6rem;
  border-radius: 12px;
  font-size: 0.75rem;
  font-weight: 600;
}

/* Canvas Styling */
canvas {
  max-width: 100%;
}

/* Custom Range Slider */
input[type=range] {
  -webkit-appearance: none;
  width: 100%;
  background: transparent;
}

input[type=range]::-webkit-slider-thumb {
  -webkit-appearance: none;
  height: 16px;
  width: 16px;
  border-radius: 50%;
  background: var(--accent-primary);
  cursor: pointer;
  margin-top: -6px;
  box-shadow: 0 0 10px rgba(0, 212, 255, 0.5);
}

input[type=range]::-webkit-slider-runnable-track {
  width: 100%;
  height: 4px;
  cursor: pointer;
  background: rgba(255,255,255,0.1);
  border-radius: 2px;
}

/* Toast */
.toast {
  position: fixed;
  bottom: 30px;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  background: rgba(17, 24, 39, 0.95);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(0, 212, 255, 0.3);
  color: #fff;
  padding: 0.75rem 1.5rem;
  border-radius: 24px;
  font-size: 0.9rem;
  font-weight: 500;
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.5), 0 0 15px rgba(0, 212, 255, 0.1);
  z-index: 1100;
  opacity: 0;
  transition: transform 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275), opacity 0.4s ease;
}

.toast.show {
  transform: translateX(-50%) translateY(0);
  opacity: 1;
}

/* Animations */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes glow {
  0% { box-shadow: 0 0 5px var(--accent-primary-glow); }
  50% { box-shadow: 0 0 20px var(--accent-primary-glow); }
  100% { box-shadow: 0 0 5px var(--accent-primary-glow); }
}

/* Application Tags */
.app-tag {
  display: inline-block;
  background: rgba(255,255,255,0.05);
  border: var(--glass-border);
  color: var(--text-secondary);
  padding: 0.25rem 0.75rem;
  border-radius: 16px;
  font-size: 0.75rem;
  margin: 0.25rem;
}

.application-tag {
  display: inline-block;
  background: rgba(0, 212, 255, 0.08);
  border: 1px solid rgba(0, 212, 255, 0.15);
  color: var(--accent-primary);
  padding: 0.3rem 0.75rem;
  border-radius: 16px;
  font-size: 0.75rem;
  margin: 0.25rem;
}

.apps-container {
  margin-bottom: 1rem;
}

/* Pros & Cons */
.pros-cons {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  margin-top: 1rem;
}

.pros h5, .cons h5 {
  font-size: 0.9rem;
  margin-bottom: 0.5rem;
}

.pros ul, .cons ul {
  list-style: none;
  padding: 0;
}

.pros li, .cons li {
  font-size: 0.8rem;
  color: var(--text-secondary);
  padding: 0.3rem 0;
}

/* Similar Material Cards */
.similar-card {
  display: inline-block;
  background: var(--surface-medium);
  border: var(--glass-border);
  border-radius: var(--border-radius-element);
  padding: 0.75rem 1rem;
  margin: 0.25rem;
  cursor: pointer;
  transition: var(--transition);
  min-width: 120px;
}

.similar-card:hover {
  background: var(--surface-hover);
  transform: translateY(-2px);
}

.similar-card h6 {
  font-size: 0.85rem;
  margin-bottom: 0.25rem;
}

.similar-card .mini-stats {
  display: flex;
  gap: 0.75rem;
  font-size: 0.7rem;
  color: var(--text-muted);
}

/* Compare Card */
.compare-card {
  flex: 1;
  background: var(--surface-light);
  border: var(--glass-border);
  border-radius: var(--border-radius-element);
  padding: 1rem;
}

.compare-card h4 {
  margin-bottom: 0.25rem;
}

.compare-props {
  margin-top: 0.75rem;
}

.compare-props .c-prop {
  display: flex;
  justify-content: space-between;
  font-size: 0.8rem;
  padding: 0.25rem 0;
  color: var(--text-secondary);
}

.compare-props .c-prop strong {
  color: var(--text-primary);
}

/* No results */
.no-results {
  text-align: center;
  padding: 3rem;
  color: var(--text-muted);
  font-size: 1.1rem;
  grid-column: 1 / -1;
}

/* Qualitative value colors */
.prop-value.qual-excellent { color: var(--cat-polymer) !important; }
.prop-value.qual-high { color: var(--cat-aluminum) !important; }
.prop-value.qual-good { color: var(--cat-aluminum) !important; }
.prop-value.qual-medium { color: #f0ad4e !important; }
.prop-value.qual-fair { color: #f0ad4e !important; }
.prop-value.qual-low { color: var(--cat-ceramic) !important; }
.prop-value.qual-poor { color: var(--cat-ceramic) !important; }

/* Unit styling */
.property-row .unit {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-left: 0.25rem;
}

/* Modal header */
#modal-header h2 {
  margin-bottom: 0.25rem;
}

#modal-header .designation {
  color: var(--text-muted);
  font-family: monospace;
  font-size: 0.85rem;
  margin-bottom: 0.5rem;
}

#modal-similar h4 {
  margin-bottom: 0.75rem;
  font-size: 0.95rem;
}

/* Responsive Design */
@media (max-width: 1024px) {
  #modal-body {
    grid-template-columns: 1fr;
  }
  
  #modal-chart-container {
    order: -1;
  }
}

@media (max-width: 768px) {
  :root {
    --sidebar-width: 0px;
  }
  
  #sidebar {
    transform: translateX(-100%);
    z-index: 90;
    width: 280px;
    transition: transform 0.3s ease;
  }
  
  #sidebar.open {
    transform: translateX(0);
  }
  
  .header-content {
    padding: 0 1rem;
  }
  
  .search-wrapper {
    display: none; /* In a real app, you'd move this or add a toggle */
  }
  
  #main-content {
    padding: 1rem;
  }
  
  .btn-primary span {
    display: none; /* Hide text, keep icon */
  }
}

/* Footer */
.site-footer {
  background: var(--bg-dark);
  border-top: var(--glass-border-light);
  padding: 2rem 0;
  margin-top: 4rem;
}
/* Custom Searchable Dropdown */
.custom-select-wrapper { position: relative; width: 100%; user-select: none; }
.custom-select { position: relative; display: flex; flex-direction: column; }
.custom-select__trigger {
  display: flex; justify-content: space-between; align-items: center;
  background: rgba(0,0,0,0.2); border: 1px solid rgba(255,255,255,0.1); color: var(--text-primary);
  padding: 0.8rem; border-radius: 8px; font-size: 1rem; cursor: pointer; transition: all 0.2s;
}
.custom-select__trigger:hover { border-color: rgba(255,255,255,0.3); }
.custom-select.open .custom-select__trigger { border-color: var(--accent-primary); border-bottom-left-radius: 0; border-bottom-right-radius: 0; }
.custom-options {
  position: absolute; display: none; top: 100%; left: 0; right: 0;
  background: var(--bg-dark); border: 1px solid rgba(255,255,255,0.1); border-top: none;
  border-bottom-left-radius: 8px; border-bottom-right-radius: 8px; z-index: 10;
  max-height: 250px; overflow-y: auto; box-shadow: 0 5px 15px rgba(0,0,0,0.5);
}
.custom-select.open .custom-options { display: block; }
.custom-option { padding: 0.8rem; color: var(--text-primary); cursor: pointer; transition: background 0.2s; }
.custom-option:hover { background: rgba(0, 212, 255, 0.1); color: var(--accent-primary); }
.custom-search {
  padding: 0.5rem; background: var(--bg-darkest); position: sticky; top: 0; z-index: 2;
  border-bottom: 1px solid rgba(255,255,255,0.1);
}
.custom-search input {
  width: 100%; background: rgba(0,0,0,0.3); border: 1px solid rgba(255,255,255,0.1);
  color: var(--text-primary); padding: 0.6rem; border-radius: 4px; outline: none;
}
.custom-search input:focus { border-color: var(--accent-primary); }

/* Copy Button */
.copy-btn {
  background: transparent; border: none; color: var(--text-muted); cursor: pointer;
  padding: 2px 5px; margin-left: 5px; border-radius: 4px; transition: all 0.2s;
  display: inline-flex; align-items: center; justify-content: center;
}
.copy-btn:hover { color: var(--accent-primary); background: rgba(255,255,255,0.05); }
.copy-btn svg { width: 14px; height: 14px; }
.copy-btn.copied { color: #2ecc71; }

.footer-content {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1.5rem;
}

.footer-brand { display: flex; flex-direction: column; gap: 0.25rem; }
.footer-logo { font-weight: 700; font-size: 1rem; color: var(--text-primary); }
.footer-brand p { font-size: 0.8rem; color: var(--text-muted); }

.footer-links { display: flex; gap: 1.5rem; }
.footer-links a { color: var(--text-secondary); text-decoration: none; font-size: 0.85rem; transition: var(--transition); }
.footer-links a:hover { color: var(--accent-primary); }

.footer-social { display: flex; gap: 1rem; }
.footer-social a { color: var(--text-muted); transition: var(--transition); }
.footer-social a:hover { color: var(--accent-primary); transform: translateY(-2px); }

.static-page .site-footer { margin-left: 0; }

.skeleton { animation: pulse-skeleton 1.5s infinite; }
@keyframes pulse-skeleton { 0% { opacity: 0.6; } 50% { opacity: 0.3; } 100% { opacity: 0.6; } }

/* Preloader */
#preloader {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
@keyframes pulse-skeleton { 0% { opacity: 0.6; } 50% { opacity: 0.3; } 100% { opacity: 0.6; } }

/* Preloader */
#preloader {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: #ffffff;
  z-index: 99999;
  display: flex;
  justify-content: center;
  align-items: center;
  transition: opacity 0.5s ease-out, visibility 0.5s ease-out;
}
#preloader.hidden {
  opacity: 0;
  visibility: hidden;
}
.loader-spinner {
  width: 60px;
  height: 60px;
  background-color: #0056b3;
  border-radius: 100%;  
  animation: sk-scaleout 1.0s infinite ease-in-out;
}
@keyframes sk-scaleout {
  0% { 
    transform: scale(0);
  } 100% {
    transform: scale(1.0);
    opacity: 0;
  }
}


/* Off-canvas sidebar styles */
#sidebar {
  position: fixed;
  top: 0;
  left: 0;
  height: 100vh;
  width: 320px;
  max-width: 85vw;
  background: var(--bg-card);
  z-index: 1000;
  transform: translateX(-100%);
  transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: 2px 0 10px rgba(0,0,0,0.5);
  overflow-y: auto;
  padding: 1.5rem;
}
#sidebar.open {
  transform: translateX(0);
}
#sidebar-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0,0,0,0.5);
  backdrop-filter: blur(3px);
  z-index: 999;
  display: none;
  opacity: 0;
  transition: opacity 0.3s ease;
}

/* Ensure chips wrap nicely */
#category-filters, #std-filters, #env-filters {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}
.filter-chip {
  padding: 0.4rem 0.8rem;
  border-radius: 20px;
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.1);
  color: var(--text-secondary);
  font-size: 0.8rem;
  cursor: pointer;
  transition: all 0.2s ease;
}
.filter-chip:hover {
  background: rgba(255,255,255,0.15);
}
.filter-chip.active {
  background: var(--accent-primary);
  color: white;
  border-color: var(--accent-primary);
  box-shadow: 0 0 10px rgba(0,86,179,0.5);
}