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

:root {
  /* Color System */
  --bg: #0a0e27;
  --bg-alt: #151935;
  --bg-card: #1a1f3a;
  --bg-card-hover: #1f2442;
  --accent: #00d4ff;
  --accent-soft: #0099cc;
  --accent-glow: rgba(0, 212, 255, 0.3);
  --text-main: #ffffff;
  --text-muted: #a0a8c5;
  --text-dim: #6b7199;
  --border: #2a3050;
  --success: #00ff88;
  --warning: #ffb800;
  --error: #ff4757;
  --card-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
  --card-shadow-hover: 0 8px 30px rgba(0, 212, 255, 0.2);

  /* Typography */
  --font-system: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 'Noto Sans', sans-serif;
  --font-heading: var(--font-system);

  /* Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 0.75rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;

  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-full: 9999px;

  /* Transitions */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);

  /* Z-index layers */
  --z-base: 1;
  --z-dropdown: 100;
  --z-sticky: 200;
  --z-overlay: 500;
  --z-modal: 1000;
}

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

body {
  font-family: var(--font-system);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--text-main);
  background-color: var(--bg);
  overflow-x: hidden;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--spacing-md);
  color: var(--text-main);
}

h1 { font-size: 2rem; }
h2 { font-size: 1.75rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }
h5 { font-size: 1.125rem; }
h6 { font-size: 1rem; }

p {
  margin-bottom: var(--spacing-md);
  color: var(--text-muted);
}

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

a:hover {
  color: var(--accent-soft);
}

/* Lists */
ul, ol {
  list-style: none;
}

/* Images */
img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* Buttons */
button {
  font-family: inherit;
  font-size: inherit;
  line-height: inherit;
  border: none;
  background: none;
  cursor: pointer;
  color: inherit;
}

/* Form elements */
input, textarea, select {
  font-family: inherit;
  font-size: inherit;
  line-height: inherit;
  color: inherit;
}

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

/* Focus styles */
:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

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

::-webkit-scrollbar-track {
  background: var(--bg-alt);
}

::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-dim);
}

/* Selection */
::selection {
  background-color: var(--accent-glow);
  color: var(--text-main);
}

/* Responsive Typography */
@media (min-width: 768px) {
  html { font-size: 17px; }
  h1 { font-size: 2.5rem; }
  h2 { font-size: 2rem; }
  h3 { font-size: 1.75rem; }
}

@media (min-width: 1024px) {
  html { font-size: 18px; }
  h1 { font-size: 3rem; }
  h2 { font-size: 2.25rem; }
  h3 { font-size: 1.875rem; }
}