/* ==========================================================================
   Natalie Slaba Portfolio - Design System
   ========================================================================== */

/* CSS Custom Properties (Design Tokens) */
:root {
  /* Color Palette - Neutral */
  --color-black: #0a0a0a;
  --color-white: #fafafa;
  --color-gray-100: #f5f5f5;
  --color-gray-200: #e5e5e5;
  --color-gray-300: #d4d4d4;
  --color-gray-400: #a3a3a3;
  --color-gray-500: #737373;
  --color-gray-600: #525252;
  --color-gray-700: #404040;
  --color-gray-800: #262626;
  --color-gray-900: #171717;

  /* Tech Side - Cool, Clean */
  --color-tech-primary: #6366f1;
  --color-tech-secondary: #818cf8;
  --color-tech-accent: #a5b4fc;
  --color-tech-bg: #0f0f1a;
  --color-tech-surface: #1a1a2e;

  /* Art Side - Warm, Organic */
  --color-art-primary: #d97706;
  --color-art-secondary: #f59e0b;
  --color-art-accent: #fbbf24;
  --color-art-bg: #1a1510;
  --color-art-surface: #2a2318;

  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-serif: 'Playfair Display', Georgia, 'Times New Roman', serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', Consolas, monospace;

  /* Spacing Scale */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;
  --space-4xl: 6rem;

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 300ms ease;
  --transition-slow: 500ms ease;
  --transition-slower: 800ms cubic-bezier(0.4, 0, 0.2, 1);

  /* Shadows */
  --shadow-sm: 0 1px 2px 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);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
  --shadow-glow-tech: 0 0 40px rgba(99, 102, 241, 0.3);
  --shadow-glow-art: 0 0 40px rgba(217, 119, 6, 0.3);
}

/* Reset & Base */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  font-family: var(--font-sans);
  line-height: 1.6;
  color: var(--color-white);
  background-color: var(--color-black);
  min-height: 100vh;
  overflow-x: hidden;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  line-height: 1.2;
  font-weight: 600;
}

h1 { font-size: clamp(2rem, 5vw, 4rem); }
h2 { font-size: clamp(1.5rem, 4vw, 3rem); }
h3 { font-size: clamp(1.25rem, 3vw, 2rem); }

p {
  max-width: 65ch;
}

a {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition-fast);
}

/* Utility Classes */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.container {
  width: 100%;
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: var(--space-md) var(--space-xl);
  font-family: var(--font-sans);
  font-size: 0.9rem;
  font-weight: 500;
  letter-spacing: 0.025em;
  text-transform: uppercase;
  border: 1px solid transparent;
  border-radius: 4px;
  cursor: pointer;
  transition: all var(--transition-base);
}

.btn-tech {
  background: transparent;
  border-color: var(--color-tech-primary);
  color: var(--color-tech-primary);
}

.btn-tech:hover {
  background: var(--color-tech-primary);
  color: var(--color-white);
  box-shadow: var(--shadow-glow-tech);
}

.btn-art {
  background: transparent;
  border-color: var(--color-art-primary);
  color: var(--color-art-primary);
}

.btn-art:hover {
  background: var(--color-art-primary);
  color: var(--color-white);
  box-shadow: var(--shadow-glow-art);
}

/* Page Transition Overlay */
.page-transition {
  position: fixed;
  inset: 0;
  z-index: 9999;
  pointer-events: none;
}

.page-transition::before,
.page-transition::after {
  content: '';
  position: absolute;
  top: 0;
  width: 50%;
  height: 100%;
  transform: scaleY(0);
  transform-origin: top;
  transition: transform var(--transition-slower);
}

.page-transition::before {
  left: 0;
  background: var(--color-tech-bg);
}

.page-transition::after {
  right: 0;
  background: var(--color-art-bg);
}

.page-transition.active::before,
.page-transition.active::after {
  transform: scaleY(1);
}

/* Loading States */
@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

.loading {
  animation: pulse 2s ease-in-out infinite;
}

/* Focus States for Accessibility */
:focus-visible {
  outline: 2px solid var(--color-tech-primary);
  outline-offset: 2px;
}

/* Selection */
::selection {
  background: var(--color-tech-primary);
  color: var(--color-white);
}

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

::-webkit-scrollbar-track {
  background: var(--color-gray-900);
}

::-webkit-scrollbar-thumb {
  background: var(--color-gray-600);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--color-gray-500);
}