:root {
  /* Colors - Based on Premium SaaS Minimalism DESIGN.md */
  --primary: #2563eb;
  --primary-on: #ffffff;
  --primary-container: #e5eeff;
  --primary-on-container: #004ac6;
  
  --surface: #ffffff;
  --surface-dim: #f8f9ff;
  --surface-bright: #ffffff;
  --surface-container-lowest: #ffffff;
  --surface-container-low: #f8fafc;
  --surface-container: #f1f5f9;
  --surface-container-high: #e2e8f0;
  --surface-container-highest: #cbd5e1;
  
  --on-surface: #0f172a;
  --on-surface-variant: #64748b;
  --outline: #e2e8f0;
  --outline-variant: #cbd5e1;
  
  --success: #10b981;
  --on-success: #ffffff;
  --warning: #f59e0b;
  --on-warning: #ffffff;
  --error: #ef4444;
  --on-error: #ffffff;
  
  /* Typography */
  --font-display: 'Geist', 'Inter', system-ui, sans-serif;
  --font-body: 'Inter', system-ui, sans-serif;
  
  /* Spacing */
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;
  --container-padding: 32px;
  
  /* Radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-full: 9999px;
  
  /* Elevation */
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --shadow-premium: 0px 4px 20px rgba(0, 0, 0, 0.03);
}

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

body {
  background-color: var(--surface-dim);
  color: var(--on-surface);
  font-family: var(--font-body);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
}

h1, h2, h3, h4, h5, h6, .label-md, .label-sm {
  font-family: var(--font-display);
  font-weight: 600;
  color: var(--on-surface);
}

/* Scrollbar */
::-webkit-scrollbar {
  width: 6px;
}
::-webkit-scrollbar-track {
  background: transparent;
}
::-webkit-scrollbar-thumb {
  background: var(--outline-variant);
  border-radius: 3px;
}
::-webkit-scrollbar-thumb:hover {
  background: var(--on-surface-variant);
}

/* Layout Components */
.app-container {
  display: flex;
  min-height: 100vh;
}

.sidebar {
  width: 280px;
  background: var(--surface);
  border-right: 1px solid var(--outline);
  display: flex;
  flex-direction: column;
  padding: var(--spacing-lg);
  flex-shrink: 0;
  position: sticky;
  top: 0;
  height: 100vh;
}

.main-content {
  flex: 1;
  padding: var(--container-padding);
  max-width: 1440px;
  margin: 0 auto;
  width: 100%;
}

/* Components */
.card {
  background: var(--surface);
  border: 1px solid var(--outline);
  border-radius: var(--radius-xl);
  padding: var(--spacing-lg);
  box-shadow: var(--shadow-premium);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.card:hover {
  box-shadow: var(--shadow-md);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: var(--radius-md);
  font-family: var(--font-display);
  font-weight: 500;
  font-size: 14px;
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  border: 1px solid transparent;
}

.btn-primary {
  background-color: var(--primary);
  color: var(--primary-on);
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.2);
}

.btn-primary:hover {
  background-color: #1d4ed8;
  transform: translateY(-1px);
  box-shadow: 0 6px 16px rgba(37, 99, 235, 0.3);
}

.btn-primary:active {
  transform: translateY(0);
}

.btn-secondary {
  background-color: var(--surface);
  border-color: var(--outline);
  color: var(--on-surface-variant);
}

.btn-secondary:hover {
  background-color: var(--surface-container-low);
  border-color: var(--outline-variant);
  color: var(--on-surface);
}

.btn-danger {
  background-color: #fff1f2;
  border-color: #fecdd3;
  color: var(--error);
}

.btn-danger:hover {
  background-color: var(--error);
  color: var(--on-error);
  border-color: var(--error);
}

.btn-ghost {
  background: transparent;
  color: var(--on-surface-variant);
}

.btn-ghost:hover {
  background: var(--surface-container);
  color: var(--on-surface);
}

.input-field {
  width: 100%;
  padding: 12px 16px;
  border-radius: var(--radius-md);
  border: 1px solid var(--outline);
  background: var(--surface);
  font-family: var(--font-body);
  font-size: 14px;
  color: var(--on-surface);
  transition: all 0.2s;
}

.input-field:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.1);
}

.input-field::placeholder {
  color: var(--on-surface-variant);
  opacity: 0.5;
}

.label-sm {
  display: block;
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--on-surface-variant);
  margin-bottom: var(--spacing-sm);
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  border-radius: var(--radius-full);
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.badge-primary { background: var(--primary-container); color: var(--primary-on-container); }
.badge-success { background: #d1fae5; color: #065f46; }
.badge-warning { background: #fef3c7; color: #92400e; }
.badge-error { background: #fee2e2; color: #991b1b; }
.badge-neutral { background: var(--surface-container); color: var(--on-surface-variant); }

/* Navigation */
.nav-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 12px;
  border-radius: var(--radius-md);
  color: var(--on-surface-variant);
  text-decoration: none;
  font-weight: 500;
  font-size: 14px;
  cursor: pointer;
  transition: all 0.2s;
}

.nav-item:hover {
  background: var(--surface-container-low);
  color: var(--on-surface);
}

.nav-item.active {
  background: var(--primary-container);
  color: var(--primary);
}

/* Typography Classes */
.text-display-lg { font-size: 48px; font-weight: 700; line-height: 1.1; letter-spacing: -0.02em; }
.text-headline-lg { font-size: 32px; font-weight: 600; line-height: 1.25; letter-spacing: -0.01em; }
.text-headline-md { font-size: 24px; font-weight: 600; line-height: 1.3; }
.text-body-lg { font-size: 18px; line-height: 1.5; }
.text-body-md { font-size: 16px; line-height: 1.5; }
.text-body-sm { font-size: 14px; line-height: 1.4; }
.text-muted { color: var(--on-surface-variant); }

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

.animate-fade-in {
  animation: fadeIn 0.4s ease-out forwards;
}

.pulse {
  animation: pulse-ring 1.5s infinite;
}

@keyframes pulse-ring {
  0% { transform: scale(0.95); opacity: 0.5; }
  50% { transform: scale(1.05); opacity: 1; }
  100% { transform: scale(0.95); opacity: 0.5; }
}

/* Specific UI elements */
.dropzone {
  border: 2px dashed var(--outline);
  border-radius: var(--radius-lg);
  padding: var(--spacing-xl);
  text-align: center;
  transition: all 0.2s;
  cursor: pointer;
  background: var(--surface-container-low);
}

.dropzone:hover {
  border-color: var(--primary);
  background: var(--primary-container);
}

.glass {
  backdrop-filter: blur(8px);
  background: rgba(255, 255, 255, 0.7);
  border: 1px solid rgba(255, 255, 255, 0.3);
}

/* Layout grids */
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: var(--spacing-lg); }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--spacing-md); }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--spacing-md); }
.grid-5 { display: grid; grid-template-columns: repeat(5, 1fr); gap: var(--spacing-sm); }

/* Sidebar bottom status */
.sidebar-footer {
  margin-top: auto;
  padding-top: var(--spacing-lg);
  border-top: 1px solid var(--outline);
}

/* Avatar specific */
.avatar-container {
  aspect-ratio: 1;
  width: 100%;
  border-radius: var(--radius-full);
  overflow: hidden;
  background: radial-gradient(circle at center, #f1f5f9 0%, #e2e8f0 100%);
  border: 4px solid var(--surface);
  box-shadow: var(--shadow-lg);
  position: relative;
}

/* Toggle Switch */
.switch {
  position: relative;
  display: inline-block;
  width: 40px;
  height: 22px;
}

.switch input {
  opacity: 0;
  width: 0;
  height: 0;
}

.slider-toggle {
  position: absolute;
  cursor: pointer;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: var(--surface-container-highest);
  transition: .3s;
  border-radius: 34px;
}

.slider-toggle:before {
  position: absolute;
  content: "";
  height: 16px;
  width: 16px;
  left: 3px;
  bottom: 3px;
  background-color: white;
  transition: .3s;
  border-radius: 50%;
}

input:checked + .slider-toggle {
  background-color: var(--primary);
}

input:checked + .slider-toggle:before {
  transform: translateX(18px);
}

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

input[type=range]:focus {
  outline: none;
}

input[type=range]::-webkit-slider-runnable-track {
  width: 100%;
  height: 6px;
  cursor: pointer;
  background: var(--surface-container-highest);
  border-radius: 3px;
}

input[type=range]::-webkit-slider-thumb {
  height: 18px;
  width: 18px;
  border-radius: 50%;
  background: var(--primary);
  cursor: pointer;
  -webkit-appearance: none;
  margin-top: -6px;
  box-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

.toggle-card {
  background: var(--surface-container-low);
  border: 1px solid var(--outline);
  border-radius: var(--radius-lg);
  padding: 12px 16px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}