/* ============================================================
   Rivera.Engineer — Design System
   Dark theme with deep purple primary
   ============================================================ */

/* --- Google Font --- */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&family=JetBrains+Mono:wght@400;500&display=swap');

/* --- Custom Properties --- */
:root {
  /* Primary Purple Palette */
  --purple-50:  #f3eaff;
  --purple-100: #e0d0ff;
  --purple-200: #c9a8ff;
  --purple-300: #ad7aff;
  --purple-400: #9553f7;
  --purple-500: #7c3aed;
  --purple-600: #6a2dd4;
  --purple-700: #5721b5;
  --purple-800: #451a96;
  --purple-900: #341370;

  /* Dark Background Palette */
  --bg-darkest:  #08080f;
  --bg-darker:   #0d0d18;
  --bg-dark:     #111122;
  --bg-card:     #16162a;
  --bg-card-hover: #1c1c38;
  --bg-surface:  #1e1e3a;

  /* Text */
  --text-primary:   #e8e6f0;
  --text-secondary: #a09bb5;
  --text-muted:     #6b6580;
  --text-accent:    var(--purple-300);

  /* Borders */
  --border-subtle:  rgba(124, 58, 237, 0.15);
  --border-card:    rgba(124, 58, 237, 0.25);
  --border-glow:    rgba(124, 58, 237, 0.4);

  /* Gradients */
  --gradient-hero: linear-gradient(135deg, #08080f 0%, #1a0a30 40%, #0d0d18 100%);
  --gradient-purple: linear-gradient(135deg, var(--purple-600), var(--purple-400));
  --gradient-card: linear-gradient(145deg, var(--bg-card) 0%, rgba(124, 58, 237, 0.06) 100%);

  /* Shadows */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
  --shadow-glow: 0 0 30px rgba(124, 58, 237, 0.15);
  --shadow-glow-lg: 0 0 60px rgba(124, 58, 237, 0.2);

  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

  /* Spacing */
  --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;

  /* Radius */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;

  /* 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);
}

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

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

body {
  font-family: var(--font-sans);
  background-color: var(--bg-darkest);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
}

a {
  color: var(--purple-300);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--purple-200);
}

/* --- Utility Classes --- */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-xl);
}

.section {
  padding: var(--space-4xl) 0;
  position: relative;
}

.section-title {
  font-size: 2.25rem;
  font-weight: 700;
  margin-bottom: var(--space-sm);
  color: var(--text-primary);
  letter-spacing: -0.02em;
}

.section-subtitle {
  font-size: 1.1rem;
  color: var(--text-secondary);
  margin-bottom: var(--space-3xl);
  max-width: 600px;
}

.section-header {
  margin-bottom: var(--space-3xl);
}

.accent-line {
  width: 60px;
  height: 3px;
  background: var(--gradient-purple);
  border-radius: 2px;
  margin-bottom: var(--space-lg);
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: 0.875rem 2rem;
  border: none;
  border-radius: var(--radius-md);
  font-family: var(--font-sans);
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-base);
  text-decoration: none;
  letter-spacing: 0.01em;
}

.btn-primary {
  background: var(--gradient-purple);
  color: white;
  box-shadow: 0 4px 20px rgba(124, 58, 237, 0.3);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 30px rgba(124, 58, 237, 0.45);
  color: white;
}

.btn-outline {
  background: transparent;
  color: var(--purple-300);
  border: 1.5px solid var(--border-card);
}

.btn-outline:hover {
  background: rgba(124, 58, 237, 0.1);
  border-color: var(--purple-400);
  color: var(--purple-200);
  transform: translateY(-2px);
}

/* --- Cards --- */
.card {
  background: var(--gradient-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: var(--space-2xl);
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--gradient-purple);
  opacity: 0;
  transition: opacity var(--transition-base);
}

.card:hover {
  border-color: var(--border-glow);
  box-shadow: var(--shadow-glow);
  transform: translateY(-4px);
}

.card:hover::before {
  opacity: 1;
}

/* --- Badge --- */
.badge {
  display: inline-flex;
  align-items: center;
  padding: 0.4rem 0.9rem;
  background: rgba(124, 58, 237, 0.12);
  border: 1px solid var(--border-subtle);
  border-radius: 100px;
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--purple-200);
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.badge:hover {
  background: rgba(124, 58, 237, 0.2);
  border-color: var(--border-card);
}

/* --- Animations --- */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes slideInLeft {
  from {
    opacity: 0;
    transform: translateX(-30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes pulse {
  0%, 100% { opacity: 0.4; }
  50% { opacity: 0.8; }
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

@keyframes gradientShift {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

.animate-fade-in-up {
  animation: fadeInUp 0.6s ease-out forwards;
  opacity: 0;
}

.animate-delay-1 { animation-delay: 0.1s; }
.animate-delay-2 { animation-delay: 0.2s; }
.animate-delay-3 { animation-delay: 0.3s; }
.animate-delay-4 { animation-delay: 0.4s; }
.animate-delay-5 { animation-delay: 0.5s; }
.animate-delay-6 { animation-delay: 0.6s; }

/* --- Responsive --- */
@media (max-width: 768px) {
  .container {
    padding: 0 var(--space-lg);
  }

  .section {
    padding: var(--space-3xl) 0;
  }

  .section-title {
    font-size: 1.75rem;
  }

  .btn {
    padding: 0.75rem 1.5rem;
    font-size: 0.9rem;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 var(--space-md);
  }

  .section-title {
    font-size: 1.5rem;
  }
}

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

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

::-webkit-scrollbar-thumb {
  background: var(--purple-800);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--purple-700);
}

/* --- Selection --- */
::selection {
  background: rgba(124, 58, 237, 0.3);
  color: white;
}