/**
 * Design System Variables - Leadup
 * Corporate & Professional Design System
 * @version 3.0.0
 * @date 2025
 */

/* ===== Font Import ===== */
@import url('https://fonts.googleapis.com/css2?family=Plus+Jakarta+Sans:wght@400;500;600;700&family=Space+Grotesk:wght@500;600;700&display=swap');

:root {
  /* ===== Typography ===== */
  --font-display: 'Space Grotesk', sans-serif;
  --font-body: 'Plus Jakarta Sans', sans-serif;

  /* Type Scale (Mobile-first) */
  --text-xs: 0.75rem;      /* 12px */
  --text-sm: 0.875rem;     /* 14px */
  --text-base: 1rem;       /* 16px */
  --text-lg: 1.125rem;     /* 18px */
  --text-xl: 1.25rem;      /* 20px */
  --text-2xl: 1.5rem;      /* 24px */
  --text-3xl: 2rem;        /* 32px */
  --text-4xl: 2.5rem;      /* 40px */
  --text-5xl: 3.5rem;      /* 56px */
  --text-6xl: 4.5rem;      /* 72px */

  /* Font Weights */
  --font-regular: 400;
  --font-medium: 500;
  --font-semibold: 600;
  --font-bold: 700;

  /* Letter Spacing */
  --tracking-tight: -0.02em;
  --tracking-normal: 0;
  --tracking-wide: 0.05em;
  --tracking-wider: 0.1em;

  /* Line Heights */
  --leading-tight: 1.2;
  --leading-snug: 1.4;
  --leading-normal: 1.6;
  --leading-relaxed: 1.8;

  /* ===== Color Palette (Simplified) ===== */

  /* Neutral Tones */
  --neutral-900: #0a0a0a;
  --neutral-800: #141414;
  --neutral-700: #1f1f1f;
  --neutral-600: #2a2a2a;
  --neutral-500: #404040;
  --neutral-400: #6b6b6b;
  --neutral-300: #8a8a8a;
  --neutral-200: #a3a3a3;
  --neutral-100: #e5e5e5;
  --neutral-50: #fafafa;

  /* Text Hierarchy */
  --text-primary: #ffffff;
  --text-secondary: rgba(255, 255, 255, 0.72);
  --text-tertiary: rgba(255, 255, 255, 0.52);
  --text-disabled: rgba(255, 255, 255, 0.32);

  /* Corporate Accent Colors */
  --accent-primary: #6366f1;      /* Indigo */
  --accent-primary-light: #818cf8;
  --accent-primary-dark: #4f46e5;
  --accent-success: #22c55e;
  --accent-success-light: #4ade80;
  --accent-warning: #f59e0b;
  --accent-error: #ef4444;

  /* Border & Surface */
  --border-subtle: rgba(255, 255, 255, 0.08);
  --border-default: rgba(255, 255, 255, 0.12);
  --border-strong: rgba(255, 255, 255, 0.20);
  --border-focus: rgba(99, 102, 241, 0.6);

  --surface-elevated: rgba(255, 255, 255, 0.04);
  --surface-hover: rgba(255, 255, 255, 0.08);
  --surface-active: rgba(255, 255, 255, 0.12);

  /* Gradients */
  --gradient-text: linear-gradient(135deg, #ffffff 0%, #a3a3a3 100%);
  --gradient-accent: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);
  --gradient-surface: linear-gradient(145deg, rgba(255,255,255,0.05) 0%, rgba(255,255,255,0.02) 100%);

  /* ===== Spacing System (8px Grid) ===== */
  --space-1: 0.25rem;   /* 4px */
  --space-2: 0.5rem;    /* 8px */
  --space-3: 0.75rem;   /* 12px */
  --space-4: 1rem;      /* 16px */
  --space-5: 1.25rem;   /* 20px */
  --space-6: 1.5rem;    /* 24px */
  --space-8: 2rem;      /* 32px */
  --space-10: 2.5rem;   /* 40px */
  --space-12: 3rem;     /* 48px */
  --space-16: 4rem;     /* 64px */
  --space-20: 5rem;     /* 80px */
  --space-24: 6rem;     /* 96px */
  --space-32: 8rem;     /* 128px */

  /* Section Spacing (Responsive) */
  --section-padding-y: clamp(4rem, 10vw, 8rem);
  --section-gap: clamp(3rem, 8vw, 6rem);
  --container-max: 80rem;
  --container-padding: 1.5rem;

  /* ===== Border Radius ===== */
  --radius-sm: 0.375rem;  /* 6px */
  --radius-md: 0.5rem;    /* 8px */
  --radius-lg: 0.75rem;   /* 12px */
  --radius-xl: 1rem;      /* 16px */
  --radius-2xl: 1.25rem;  /* 20px */
  --radius-full: 9999px;

  /* ===== Shadows ===== */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.5);
  --shadow-xl: 0 20px 50px rgba(0, 0, 0, 0.6);
  --shadow-glow: 0 0 30px rgba(99, 102, 241, 0.3);
  --shadow-glow-strong: 0 0 50px rgba(99, 102, 241, 0.5);

  /* ===== Transitions ===== */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
  --transition-spring: 0.4s cubic-bezier(0.16, 1, 0.3, 1);

  /* ===== Z-Index Scale ===== */
  --z-base: 1;
  --z-dropdown: 100;
  --z-sticky: 500;
  --z-header: 1000;
  --z-modal-backdrop: 9000;
  --z-modal: 9999;
}

/* ===== Scroll Animation Classes ===== */
.fade-up {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s cubic-bezier(0.16, 1, 0.3, 1), transform 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

.fade-up.visible {
  opacity: 1;
  transform: translateY(0);
}

.fade-in {
  opacity: 0;
  transition: opacity 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

.fade-in.visible {
  opacity: 1;
}

/* Staggered Children Animation */
.stagger-children > * {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.5s cubic-bezier(0.16, 1, 0.3, 1), transform 0.5s cubic-bezier(0.16, 1, 0.3, 1);
}

.stagger-children.visible > *:nth-child(1) { transition-delay: 0.1s; }
.stagger-children.visible > *:nth-child(2) { transition-delay: 0.2s; }
.stagger-children.visible > *:nth-child(3) { transition-delay: 0.3s; }
.stagger-children.visible > *:nth-child(4) { transition-delay: 0.4s; }
.stagger-children.visible > *:nth-child(5) { transition-delay: 0.5s; }
.stagger-children.visible > *:nth-child(6) { transition-delay: 0.6s; }

.stagger-children.visible > * {
  opacity: 1;
  transform: translateY(0);
}

/* ===== Global Typography Resets ===== */
body {
  font-family: var(--font-body);
  font-size: var(--text-base);
  line-height: var(--leading-normal);
  color: var(--text-primary);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: var(--font-semibold);
  line-height: var(--leading-tight);
  letter-spacing: var(--tracking-tight);
}

/* ===== Focus Styles (Accessibility) ===== */
:focus-visible {
  outline: 2px solid var(--accent-primary);
  outline-offset: 3px;
}

a:focus-visible,
button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible {
  outline: 2px solid var(--accent-primary);
  outline-offset: 3px;
}

/* ===== Skip Link (Accessibility) ===== */
.skip-link {
  position: absolute;
  top: -100%;
  left: 50%;
  transform: translateX(-50%);
  padding: var(--space-3) var(--space-6);
  background: var(--accent-primary);
  color: var(--text-primary);
  font-weight: var(--font-semibold);
  text-decoration: none;
  border-radius: var(--radius-md);
  z-index: calc(var(--z-modal) + 1);
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: var(--space-4);
}

/* ===== Responsive Typography ===== */
@media (max-width: 768px) {
  :root {
    --text-5xl: 2.5rem;   /* 40px on mobile */
    --text-6xl: 3rem;     /* 48px on mobile */
  }
}