:root {
  --color-primary: #4F46E5;
  --color-primary-hover: #4338CA;
  --color-primary-light: #EEF2FF;
  --color-primary-dark: #3730A3;
  --color-success: #10B981;
  --color-success-light: #D1FAE5;
  --color-danger: #EF4444;
  --color-danger-hover: #DC2626;
  --color-danger-light: #FEE2E2;
  --color-warning: #F59E0B;
  --color-warning-light: #FEF3C7;
  --color-info: #3B82F6;
  --color-info-light: #DBEAFE;
  --color-surface: #FFFFFF;
  --color-surface-alt: #F9FAFB;
  --color-background: #F3F4F6;
  --color-border: #E5E7EB;
  --color-border-focus: #4F46E5;
  --color-text-primary: #111827;
  --color-text-secondary: #6B7280;
  --color-text-tertiary: #9CA3AF;
  --color-text-on-primary: #FFFFFF;
  --color-overlay: rgba(0, 0, 0, 0.45);

  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-full: 9999px;

  --shadow-xs: 0 1px 2px rgba(0,0,0,0.05);
  --shadow-sm: 0 2px 6px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.10);
  --shadow-lg: 0 10px 25px rgba(0,0,0,0.12);
  --shadow-xl: 0 20px 40px rgba(0,0,0,0.16);

  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-size-xs: 11px;
  --font-size-sm: 12px;
  --font-size-base: 14px;
  --font-size-md: 16px;
  --font-size-lg: 20px;
  --font-size-xl: 24px;
  --font-size-2xl: 32px;

  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;

  --spacing-1: 4px;
  --spacing-2: 8px;
  --spacing-3: 12px;
  --spacing-4: 16px;
  --spacing-5: 20px;
  --spacing-6: 24px;
  --spacing-8: 32px;
  --spacing-10: 40px;
  --spacing-12: 48px;

  --transition-fast: 150ms ease;
  --transition-base: 200ms ease;
  --transition-slow: 300ms ease;

  --header-height: 56px;
  --statusbar-height: 28px;
  --palette-width: 240px;
  --properties-width: 300px;
}

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

html { font-size: 16px; -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale; }

body {
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  color: var(--color-text-primary);
  background: var(--color-background);
  line-height: 1.5;
  min-height: 100vh;
  overflow: hidden;
}

h1, h2, h3, h4, h5, h6 {
  font-weight: var(--font-weight-semibold);
  line-height: 1.3;
}

a { color: var(--color-primary); text-decoration: none; }
a:hover { text-decoration: underline; }

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

input, textarea, select {
  font-family: inherit;
  font-size: var(--font-size-base);
  color: var(--color-text-primary);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-surface);
  outline: none;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
  width: 100%;
}

input:focus, textarea:focus, select:focus {
  border-color: var(--color-border-focus);
  box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.15);
}

input[type="checkbox"], input[type="radio"] {
  width: auto;
  accent-color: var(--color-primary);
  cursor: pointer;
}

label {
  display: block;
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-1);
}

.sr-only, .sr-announcer {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
  border: 0;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-2);
  padding: 6px 14px;
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-medium);
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  transition: background var(--transition-fast), color var(--transition-fast),
              border-color var(--transition-fast), box-shadow var(--transition-fast),
              transform var(--transition-fast);
  white-space: nowrap;
  user-select: none;
}

.btn:active { transform: scale(0.97); }
.btn:disabled { opacity: 0.45; cursor: not-allowed; transform: none; }

.btn--primary {
  background: var(--color-primary);
  color: var(--color-text-on-primary);
  border-color: var(--color-primary);
}
.btn--primary:hover:not(:disabled) { background: var(--color-primary-hover); border-color: var(--color-primary-hover); }

.btn--ghost {
  background: transparent;
  color: var(--color-text-secondary);
  border-color: transparent;
}
.btn--ghost:hover:not(:disabled) { background: var(--color-background); color: var(--color-text-primary); }

.btn--outline {
  background: transparent;
  color: var(--color-primary);
  border-color: var(--color-border);
}
.btn--outline:hover:not(:disabled) { background: var(--color-primary-light); border-color: var(--color-primary); }

.btn--danger {
  background: var(--color-danger);
  color: white;
  border-color: var(--color-danger);
}
.btn--danger:hover:not(:disabled) { background: var(--color-danger-hover); border-color: var(--color-danger-hover); }

.btn--ghost.btn--danger { background: transparent; color: var(--color-danger); }
.btn--ghost.btn--danger:hover:not(:disabled) { background: var(--color-danger-light); }

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

.btn--sm { padding: 4px 10px; font-size: var(--font-size-sm); }
.btn--lg { padding: 10px 20px; font-size: var(--font-size-md); }
.btn--icon { padding: 6px; }
.btn--icon-text { gap: var(--spacing-1); }

.btn-separator {
  width: 1px;
  height: 24px;
  background: var(--color-border);
  margin: 0 var(--spacing-1);
}

.tag {
  display: inline-flex;
  align-items: center;
  padding: 2px 8px;
  border-radius: var(--radius-full);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-medium);
}

.tag--primary { background: var(--color-primary-light); color: var(--color-primary); }
.tag--success { background: var(--color-success-light); color: var(--color-success); }
.tag--danger { background: var(--color-danger-light); color: var(--color-danger); }
.tag--warning { background: var(--color-warning-light); color: var(--color-warning); }

:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

::selection { background: var(--color-primary-light); }

::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--color-border); border-radius: var(--radius-full); }
::-webkit-scrollbar-thumb:hover { background: var(--color-text-tertiary); }