:root {
  --bg-gradient: linear-gradient(135deg, #090d16, #111827);
  --card-bg: rgba(17, 24, 39, 0.7);
  --card-border: rgba(255, 255, 255, 0.08);
  --text-primary: #f9fafb;
  --text-secondary: #9ca3af;
  --accent-cyan: #06b6d4;
  --accent-blue: #3b82f6;
  --accent-purple: #8b5cf6;
  --accent-gradient: linear-gradient(135deg, #06b6d4, #3b82f6, #8b5cf6);
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

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

body, html {
  width: 100%;
  height: 100%;
  overflow: hidden;
  font-family: var(--font-family);
  background: var(--bg-gradient);
  color: var(--text-primary);
}

.back-to-studios {
  position: fixed; 
  top: 20px; 
  left: 20px; 
  z-index: 99999;
  background: rgba(15, 23, 42, 0.7); 
  backdrop-filter: blur(8px);
  color: white; 
  padding: 10px 20px; 
  border-radius: 12px;
  border: 1px solid rgba(255, 255, 255, 0.1); 
  cursor: pointer;
  font-size: 14px; 
  font-weight: 600;
  text-decoration: none; 
  display: flex; 
  align-items: center; 
  gap: 8px;
  transition: all 0.3s ease; 
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
}

.back-to-studios:hover { 
  background: var(--accent-cyan); 
  border-color: var(--accent-cyan);
  transform: translateY(-2px); 
  box-shadow: 0 0 15px rgba(6, 182, 212, 0.4);
}

.app-container {
  display: flex;
  width: 100%;
  height: 100%;
  position: relative;
}

.sidebar {
  width: 360px;
  height: 100%;
  background: var(--card-bg);
  backdrop-filter: blur(16px);
  border-right: 1px solid var(--card-border);
  padding: 80px 24px 24px 24px;
  display: flex;
  flex-direction: column;
  gap: 20px;
  overflow-y: auto;
  z-index: 10;
  box-shadow: 4px 0 25px rgba(0, 0, 0, 0.5);
}

.sidebar-header {
  display: flex;
  align-items: center;
  gap: 12px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
  padding-bottom: 15px;
}

.logo {
  width: 42px;
  height: 42px;
  border-radius: 10px;
  background: var(--accent-gradient);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 18px;
  color: white;
  box-shadow: 0 0 20px rgba(6, 182, 212, 0.4);
}

.app-title {
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -0.5px;
}

.app-subtitle {
  font-size: 11px;
  color: var(--text-secondary);
  margin-top: 2px;
}

.panel-section {
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid rgba(255, 255, 255, 0.04);
  border-radius: 14px;
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.panel-section h2 {
  font-size: 12px;
  font-weight: 700;
  color: var(--accent-cyan);
  text-transform: uppercase;
  letter-spacing: 0.8px;
}

.drop-zone {
  border: 2px dashed rgba(255, 255, 255, 0.15);
  border-radius: 12px;
  padding: 24px 16px;
  text-align: center;
  cursor: pointer;
  transition: all 0.3s ease;
  background: rgba(255, 255, 255, 0.01);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
}

.drop-zone:hover, .drop-zone.dragover {
  border-color: var(--accent-cyan);
  background: rgba(6, 182, 212, 0.04);
  box-shadow: inset 0 0 15px rgba(6, 182, 212, 0.05);
}

.upload-icon {
  color: var(--text-secondary);
  transition: color 0.3s ease;
}

.drop-zone:hover .upload-icon {
  color: var(--accent-cyan);
}

.drop-text {
  font-size: 13px;
  font-weight: 500;
  color: var(--text-primary);
}

.formats-text {
  font-size: 10px;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.info-grid {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.info-row {
  display: flex;
  justify-content: space-between;
  font-size: 13px;
  padding-bottom: 6px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.03);
}

.info-label {
  color: var(--text-secondary);
}

.info-value {
  font-weight: 600;
  color: var(--text-primary);
  max-width: 180px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.qr-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  padding: 8px 0;
}

.qr-spinner-wrapper {
  height: 150px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
}

#qr-code-img {
  width: 160px;
  height: 160px;
  border-radius: 12px;
  border: 4px solid #111827;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.5);
  background: white;
  padding: 8px;
}

.qr-hint {
  font-size: 11px;
  color: var(--text-secondary);
  text-align: center;
  line-height: 1.4;
}

.qr-error-msg {
  font-size: 11px;
  color: #ef4444;
  text-align: center;
}

.help-list {
  padding-left: 18px;
  font-size: 12px;
  color: var(--text-secondary);
  display: flex;
  flex-direction: column;
  gap: 8px;
  line-height: 1.4;
}

.preview-area {
  flex-grow: 1;
  height: 100%;
  position: relative;
  background: radial-gradient(circle at 50% 50%, #111827, #070a10);
}

/* Custom Controls and Premium Styling */
.custom-control-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-bottom: 12px;
}

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

.control-label {
  font-size: 11px;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.color-palette {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding: 4px 0;
}

.color-btn {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  border: 1px solid rgba(255, 255, 255, 0.2);
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: 0 2px 5px rgba(0,0,0,0.3);
}

.color-btn:hover {
  transform: scale(1.15);
  border-color: rgba(255, 255, 255, 0.6);
}

.color-btn.active {
  transform: scale(1.2);
  border-color: white;
  box-shadow: 0 0 12px var(--accent-cyan);
}

.lighting-presets {
  display: flex;
  background: rgba(0, 0, 0, 0.2);
  border: 1px solid rgba(255, 255, 255, 0.05);
  border-radius: 8px;
  padding: 3px;
  gap: 4px;
}

.light-btn {
  flex-grow: 1;
  background: transparent;
  border: none;
  color: var(--text-secondary);
  font-size: 11px;
  font-weight: 600;
  padding: 8px 12px;
  border-radius: 6px;
  cursor: pointer;
  transition: all 0.2s ease;
}

.light-btn:hover {
  color: var(--text-primary);
  background: rgba(255, 255, 255, 0.03);
}

.light-btn.active {
  color: white;
  background: var(--accent-gradient);
  box-shadow: 0 2px 10px rgba(6, 182, 212, 0.25);
}

.slider-label-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

#exposure-val {
  font-size: 11px;
  font-weight: 700;
  color: var(--accent-cyan);
  background: rgba(6, 182, 212, 0.1);
  padding: 2px 6px;
  border-radius: 4px;
}

.custom-slider {
  -webkit-appearance: none;
  width: 100%;
  height: 6px;
  border-radius: 3px;
  background: rgba(255, 255, 255, 0.1);
  outline: none;
  cursor: pointer;
  transition: background 0.3s;
}

.custom-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--accent-cyan);
  box-shadow: 0 0 10px rgba(6, 182, 212, 0.5);
  cursor: pointer;
  transition: transform 0.1s;
}

.custom-slider::-webkit-slider-thumb:hover {
  transform: scale(1.2);
}

/* Floating Overlay Action Controls */
.floating-controls {
  position: absolute;
  top: 20px;
  right: 20px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  z-index: 100;
}

.floating-btn {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: rgba(15, 23, 42, 0.6);
  backdrop-filter: blur(8px);
  border: 1px solid rgba(255, 255, 255, 0.1);
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
}

.floating-btn:hover {
  color: white;
  border-color: var(--accent-cyan);
  transform: translateY(-2px);
  box-shadow: 0 0 15px rgba(6, 182, 212, 0.4);
}

.floating-btn.active {
  color: white;
  border-color: var(--accent-cyan);
  background: rgba(6, 182, 212, 0.2);
  box-shadow: 0 0 15px rgba(6, 182, 212, 0.3);
}

.placeholder-content {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  color: var(--text-secondary);
  text-align: center;
}

.placeholder-content svg {
  color: rgba(255, 255, 255, 0.15);
}

.placeholder-content h3 {
  font-size: 18px;
  font-weight: 600;
  color: var(--text-primary);
}

.placeholder-content p {
  font-size: 13px;
  max-width: 320px;
  line-height: 1.5;
}

.loader-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(9, 13, 22, 0.85);
  backdrop-filter: blur(8px);
  z-index: 20;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 16px;
}

.spinner {
  width: 40px;
  height: 40px;
  border: 3px solid rgba(6, 182, 212, 0.1);
  border-top-color: var(--accent-cyan);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

.spinner-text {
  font-size: 12px;
  color: var(--text-secondary);
  animation: pulse 1.5s infinite ease-in-out;
}

#loader-text {
  font-size: 14px;
  color: var(--text-primary);
  font-weight: 500;
}

/* Customized model-viewer AR Button styling */
#ar-button {
  background-color: #111827;
  background-image: var(--accent-gradient);
  background-size: 200% auto;
  border-radius: 30px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  color: white;
  height: 48px;
  padding: 0 24px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.8px;
  display: flex;
  align-items: center;
  gap: 10px;
  cursor: pointer;
  position: absolute;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 99;
  box-shadow: 0 4px 20px rgba(6, 182, 212, 0.4);
  transition: all 0.3s ease;
}

#ar-button:hover {
  background-position: right center;
  box-shadow: 0 0 25px rgba(6, 182, 212, 0.6);
  transform: translateX(-50%) translateY(-2px);
}

#ar-button:active {
  transform: translateX(-50%) translateY(0);
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

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

/* Responsive query for mobile screens */
@media (max-width: 767px) {
  .app-container {
    flex-direction: column-reverse;
    height: 100vh;
    overflow: hidden;
  }

  .sidebar {
    width: 100%;
    height: 45vh;
    border-right: none;
    border-top: 1px solid var(--card-border);
    padding: 20px 16px;
    box-shadow: 0 -4px 25px rgba(0, 0, 0, 0.5);
    overflow-y: auto;
    flex-shrink: 0;
  }

  .preview-area {
    width: 100%;
    height: 55vh;
    flex-shrink: 0;
    position: relative;
  }

  #qr-section {
    display: none !important; /* Hide transfer section on mobile device */
  }

  .floating-controls {
    top: 12px;
    right: 12px;
    gap: 8px;
  }

  .floating-btn {
    width: 38px;
    height: 38px;
  }

  .back-to-studios {
    top: 12px;
    left: 12px;
    padding: 8px 16px;
    font-size: 13px;
  }

  #ar-button {
    bottom: 16px;
    height: 44px;
    padding: 0 18px;
    font-size: 11px;
    box-shadow: 0 4px 15px rgba(6, 182, 212, 0.3);
  }
}

/* Material Studio preset buttons */
.mat-btn {
  border: 2px solid transparent;
  border-radius: 8px;
  height: 44px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s ease;
  position: relative;
}
.mat-btn:hover {
  border-color: rgba(6, 182, 212, 0.6);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(0,0,0,0.4);
}
.mat-btn.active {
  border-color: #06b6d4 !important;
  box-shadow: 0 0 10px rgba(6, 182, 212, 0.5);
}