/* ==========================================================================
   Design System & CSS Custom Properties
   ========================================================================== */

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

:root {
  /* Colors - Deep Premium Dark Theme */
  --bg-primary: hsl(225, 25%, 8%);
  --bg-secondary: hsl(225, 20%, 12%);
  --bg-card: hsl(225, 18%, 14%);
  --bg-elevated: hsl(225, 16%, 18%);
  --bg-input: hsl(225, 20%, 10%);
  
  /* Accent Colors */
  --accent-primary: hsl(210, 100%, 56%);  /* Vibrant Blue */
  --accent-secondary: hsl(180, 85%, 55%); /* Cyan */
  --accent-gradient: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
  
  /* Text Colors */
  --text-primary: hsl(0, 0%, 95%);
  --text-secondary: hsl(225, 15%, 65%);
  --text-muted: hsl(225, 12%, 45%);
  
  /* Status Colors */
  --success: hsl(145, 65%, 50%);
  --warning: hsl(40, 95%, 60%);
  --error: hsl(0, 75%, 60%);
  
  /* Glassmorphism */
  --glass-bg: rgba(255, 255, 255, 0.05);
  --glass-border: rgba(255, 255, 255, 0.08);
  
  /* Typography */
  --font-heading: 'Outfit', sans-serif;
  --font-body: 'Inter', sans-serif;
  --font-mono: 'JetBrains Mono', monospace;
  
  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-xxl: 3rem;
  
  /* Borders & Shadows */
  --border-radius-sm: 8px;
  --border-radius: 12px;
  --border-radius-lg: 16px;
  --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 20px rgba(59, 130, 246, 0.15);
  
  /* Animation */
  --transition: all 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

/* ==========================================================================
   Typography Base
   ========================================================================== */
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-primary);
}

h1 { font-size: clamp(2rem, 5vw, 3.5rem); }
h2 { font-size: clamp(1.75rem, 4vw, 2.5rem); }
h3 { font-size: clamp(1.5rem, 3vw, 2rem); }
h4 { font-size: 1.25rem; }

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

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

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

ul, ol {
  margin-bottom: var(--spacing-md);
  padding-left: var(--spacing-xl);
  color: var(--text-secondary);
}

li {
  margin-bottom: var(--spacing-xs);
}

strong, b {
  font-weight: 600;
  color: var(--text-primary);
}

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

.text-gradient {
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  display: inline-block;
}

.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;
}

.text-center { text-align: center; }
.mb-1 { margin-bottom: var(--spacing-sm); }
.mb-2 { margin-bottom: var(--spacing-md); }
.mb-3 { margin-bottom: var(--spacing-lg); }
.mb-4 { margin-bottom: var(--spacing-xl); }
.mb-5 { margin-bottom: var(--spacing-xxl); }

/* ==========================================================================
   Animations
   ========================================================================== */
@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes slideUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes slideDown {
  from { opacity: 0; transform: translateY(-20px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes pulse {
  0% { transform: scale(1); }
  50% { transform: scale(1.05); }
  100% { transform: scale(1); }
}

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

@keyframes glow {
  0% { box-shadow: 0 0 5px rgba(59, 130, 246, 0.2); }
  50% { box-shadow: 0 0 20px rgba(59, 130, 246, 0.6); }
  100% { box-shadow: 0 0 5px rgba(59, 130, 246, 0.2); }
}

/* Animation Classes */
.animate-fade-in { animation: fadeIn 0.6s ease-out forwards; }
.animate-slide-up { animation: slideUp 0.6s ease-out forwards; }
.animate-slide-down { animation: slideDown 0.6s ease-out forwards; }

/* Scroll Animations (handled by JS) */
.animate-on-scroll {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}

.animate-on-scroll.animated {
  opacity: 1;
  transform: translateY(0);
}

/* ==========================================================================
   Scrollbar & Selection
   ========================================================================== */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

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

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

::-webkit-scrollbar-thumb:hover {
  background: var(--accent-primary);
}

::selection {
  background: rgba(59, 130, 246, 0.3);
  color: white;
}

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

/* Light Theme Variables Override */
body.light-theme {
  --bg-primary: hsl(220, 20%, 96%);
  --bg-secondary: hsl(220, 18%, 92%);
  --bg-card: hsl(220, 16%, 98%);
  --bg-elevated: hsl(0, 0%, 100%);
  --bg-input: hsl(220, 15%, 90%);
  
  --text-primary: hsl(220, 25%, 12%);
  --text-secondary: hsl(220, 15%, 35%);
  --text-muted: hsl(220, 10%, 55%);
  
  --glass-bg: rgba(255, 255, 255, 0.45);
  --glass-border: rgba(0, 0, 0, 0.08);
  
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.08);
  --shadow-glow: 0 0 20px rgba(59, 130, 246, 0.05);
  
  --navbar-bg: rgba(240, 242, 248, 0.85);
}