/* ============================================
   NexusForge Design System
   Enterprise-grade CSS foundation
   ============================================ */

/* --- CSS Custom Properties --- */
:root {
  /* Colors - Dark Professional Palette */
  --color-bg-primary: #09090b;
  --color-bg-secondary: #111113;
  --color-bg-tertiary: #18181b;
  --color-bg-elevated: #1c1c1f;
  --color-bg-card: #141416;
  --color-bg-card-hover: #1a1a1d;

  --color-border: rgba(255, 255, 255, 0.06);
  --color-border-hover: rgba(255, 255, 255, 0.12);
  --color-border-active: rgba(255, 255, 255, 0.2);

  --color-text-primary: #fafafa;
  --color-text-secondary: #a1a1aa;
  --color-text-tertiary: #71717a;
  --color-text-muted: #52525b;

  /* Accent - Electric Blue */
  --color-accent: #3b82f6;
  --color-accent-hover: #2563eb;
  --color-accent-light: rgba(59, 130, 246, 0.12);
  --color-accent-glow: rgba(59, 130, 246, 0.25);

  /* Success / Error */
  --color-success: #22c55e;
  --color-error: #ef4444;

  /* Typography Scale (Major Third - 1.25) */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

  --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: 1.875rem;   /* 30px */
  --text-4xl: 2.25rem;    /* 36px */
  --text-5xl: 3rem;       /* 48px */
  --text-6xl: 3.75rem;    /* 60px */
  --text-7xl: 4.5rem;     /* 72px */

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

  --leading-tight: 1.15;
  --leading-snug: 1.3;
  --leading-normal: 1.5;
  --leading-relaxed: 1.7;

  --tracking-tight: -0.025em;
  --tracking-normal: 0;
  --tracking-wide: 0.05em;
  --tracking-wider: 0.1em;

  /* Spacing (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 */

  /* Layout */
  --container-max: 1200px;
  --container-narrow: 800px;
  --container-wide: 1400px;

  /* Borders */
  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-2xl: 24px;
  --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 8px 24px rgba(0, 0, 0, 0.5);
  --shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.6);
  --shadow-glow: 0 0 40px var(--color-accent-glow);

  /* 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: 400ms cubic-bezier(0.4, 0, 0.2, 1);

  /* Z-Index Scale */
  --z-base: 1;
  --z-dropdown: 10;
  --z-sticky: 20;
  --z-overlay: 30;
  --z-modal: 40;
  --z-toast: 50;
}


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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-family);
  font-size: var(--text-base);
  font-weight: var(--font-normal);
  line-height: var(--leading-normal);
  color: var(--color-text-primary);
  background-color: var(--color-bg-primary);
  overflow-x: hidden;
}

img, video, svg {
  display: block;
  max-width: 100%;
  height: auto;
}

a {
  color: inherit;
  text-decoration: none;
}

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

ul, ol {
  list-style: none;
}

input, textarea, select {
  font: inherit;
  color: inherit;
}


/* --- Layout --- */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.container--narrow {
  max-width: var(--container-narrow);
}

.container--wide {
  max-width: var(--container-wide);
}

.section {
  padding: var(--space-20) 0;
}

.section--lg {
  padding: var(--space-32) 0;
}


/* --- Typography --- */
h1, h2, h3, h4, h5, h6 {
  font-weight: var(--font-semibold);
  line-height: var(--leading-tight);
  letter-spacing: var(--tracking-tight);
  color: var(--color-text-primary);
}

h1 { font-size: var(--text-5xl); }
h2 { font-size: var(--text-4xl); }
h3 { font-size: var(--text-2xl); }
h4 { font-size: var(--text-xl); }

@media (min-width: 768px) {
  h1 { font-size: var(--text-6xl); }
  h2 { font-size: var(--text-5xl); }
  h3 { font-size: var(--text-3xl); }
}

@media (min-width: 1024px) {
  h1 { font-size: var(--text-7xl); }
}

.text-gradient {
  background: linear-gradient(135deg, var(--color-text-primary) 0%, var(--color-text-secondary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.text-accent {
  color: var(--color-accent);
}

.text-secondary {
  color: var(--color-text-secondary);
}

.text-muted {
  color: var(--color-text-tertiary);
}

.overline {
  font-size: var(--text-xs);
  font-weight: var(--font-semibold);
  letter-spacing: var(--tracking-wider);
  text-transform: uppercase;
  color: var(--color-accent);
}

.lead {
  font-size: var(--text-lg);
  line-height: var(--leading-relaxed);
  color: var(--color-text-secondary);
}

@media (min-width: 768px) {
  .lead { font-size: var(--text-xl); }
}


/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  font-size: var(--text-sm);
  font-weight: var(--font-medium);
  line-height: 1;
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
  white-space: nowrap;
  cursor: pointer;
}

.btn--primary {
  background: var(--color-accent);
  color: white;
}

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

.btn--secondary {
  background: transparent;
  color: var(--color-text-primary);
  border: 1px solid var(--color-border-hover);
}

.btn--secondary:hover {
  border-color: var(--color-border-active);
  background: rgba(255, 255, 255, 0.04);
}

.btn--ghost {
  background: transparent;
  color: var(--color-text-secondary);
}

.btn--ghost:hover {
  color: var(--color-text-primary);
  background: rgba(255, 255, 255, 0.04);
}

.btn--lg {
  padding: var(--space-4) var(--space-8);
  font-size: var(--text-base);
  border-radius: var(--radius-lg);
}

.btn--sm {
  padding: var(--space-2) var(--space-4);
  font-size: var(--text-xs);
}

.btn--full {
  width: 100%;
}


/* --- Cards --- */
.card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-8);
  transition: all var(--transition-base);
}

.card:hover {
  border-color: var(--color-border-hover);
  background: var(--color-bg-card-hover);
}

.card--elevated {
  box-shadow: var(--shadow-md);
}

.card--elevated:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}


/* --- Grid --- */
.grid {
  display: grid;
  gap: var(--space-6);
}

.grid--2 { grid-template-columns: 1fr; }
.grid--3 { grid-template-columns: 1fr; }
.grid--4 { grid-template-columns: 1fr; }

@media (min-width: 640px) {
  .grid--2 { grid-template-columns: repeat(2, 1fr); }
  .grid--3 { grid-template-columns: repeat(2, 1fr); }
  .grid--4 { grid-template-columns: repeat(2, 1fr); }
}

@media (min-width: 1024px) {
  .grid--3 { grid-template-columns: repeat(3, 1fr); }
  .grid--4 { grid-template-columns: repeat(4, 1fr); }
}


/* --- Badge --- */
.badge {
  display: inline-flex;
  align-items: center;
  padding: var(--space-1) var(--space-3);
  font-size: var(--text-xs);
  font-weight: var(--font-medium);
  border-radius: var(--radius-full);
  background: var(--color-accent-light);
  color: var(--color-accent);
  border: 1px solid rgba(59, 130, 246, 0.2);
}


/* --- Divider --- */
.divider {
  height: 1px;
  background: var(--color-border);
  border: none;
}


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

.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.gap-2 { gap: var(--space-2); }
.gap-4 { gap: var(--space-4); }
.gap-6 { gap: var(--space-6); }
.gap-8 { gap: var(--space-8); }
.text-center { text-align: center; }
.mx-auto { margin-left: auto; margin-right: auto; }
.mt-4 { margin-top: var(--space-4); }
.mt-6 { margin-top: var(--space-6); }
.mt-8 { margin-top: var(--space-8); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-6 { margin-bottom: var(--space-6); }
.mb-8 { margin-bottom: var(--space-8); }

/* Fade-in animation */
.fade-in {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

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