/* ===== CSS VARIABLES (Material Design 3 + Apple HIG) ===== */
:root {
  /* Colors - Material Design 3 inspired */
  --primary: #f44336;
  --primary-dark: #d32f2f;
  --primary-light: #ff5252;
  --secondary: #4caf50;
  --secondary-dark: #388e3c;
  --accent: #ffd700;
  --error: #f44336;
  --warning: #ff9800;

  /* Surfaces - Apple inspired elevation */
  --surface-0: #1e1e1e;
  --surface-1: #252525;
  --surface-2: #2d2d2d;
  --surface-3: #353535;
  --surface-4: #3d3d3d;

  /* Text */
  --text-primary: #ffffff;
  --text-secondary: #b0b0b0;
  --text-tertiary: #808080;
  --text-disabled: #4d4d4d;

  /* Spacing */
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;
  --spacing-2xl: 48px;

  /* Border Radius - Apple style */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 20px;
  --radius-full: 9999px;

  /* Shadows - Material elevation */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.12), 0 1px 2px rgba(0, 0, 0, 0.24);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.2);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.3);
  --shadow-xl: 0 12px 48px rgba(0, 0, 0, 0.4);

  /* 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);

  /* Typography */
  --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', sans-serif;
  --font-mono: 'SF Mono', 'Consolas', 'Monaco', monospace;
}

/* ===== RESET & BASE ===== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

body {
  font-family: var(--font-family);
  background: linear-gradient(135deg, var(--surface-0) 0%, var(--surface-1) 100%);
  color: var(--text-primary);
  min-height: 100vh;
  padding: var(--spacing-lg);
  line-height: 1.6;
  transition: all var(--transition-base);
}

/* ===== ACCESSIBILITY ===== */
*:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

button,
a,
input,
select {
  -webkit-tap-highlight-color: transparent;
}

/* Reduced motion support */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* ===== LAYOUT ===== */
.container {
  max-width: 1400px;
  margin: 0 auto;
  width: 100%;
}

/* Shared Button Styles */
.primary-btn {
  background: var(--primary);
  color: white;
  border: none;
  padding: 10px 20px;
  border-radius: var(--radius-md);
  cursor: pointer;
  font-weight: 600;
  transition: background var(--transition-fast);
}

.primary-btn:hover {
  background: var(--primary-dark);
}

.secondary-btn {
  background: var(--surface-3);
  color: var(--text-primary);
  border: 1px solid var(--text-tertiary);
  padding: 8px 16px;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.secondary-btn:hover {
  background: var(--surface-4);
  border-color: var(--text-secondary);
}