/* ============================================
   AKHWAND AHMED BILAL - PORTFOLIO WEBSITE
   Modern Design System with Glassmorphism
   ============================================ */

/* ============================================
   CSS CUSTOM PROPERTIES (Design Tokens)
   ============================================ */
:root {
  /* Colors - Vibrant Dark Theme */
  --primary: hsl(190, 95%, 50%);
  --primary-light: hsl(190, 95%, 60%);
  --primary-dark: hsl(190, 95%, 40%);
  
  --secondary: hsl(220, 90%, 55%);
  --secondary-light: hsl(220, 90%, 65%);
  --secondary-dark: hsl(220, 90%, 45%);
  
  --accent: hsl(280, 85%, 60%);
  --accent-light: hsl(280, 85%, 70%);
  
  --background: hsl(220, 20%, 10%);
  --surface: hsl(220, 18%, 15%);
  --surface-light: hsl(220, 18%, 20%);
  
  --text-primary: hsl(0, 0%, 95%);
  --text-secondary: hsl(0, 0%, 70%);
  --text-muted: hsl(0, 0%, 50%);
  
  --success: hsl(142, 76%, 45%);
  --warning: hsl(45, 100%, 51%);
  --error: hsl(0, 84%, 60%);
  
  /* Gradients */
  --gradient-primary: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  --gradient-accent: linear-gradient(135deg, var(--secondary) 0%, var(--accent) 100%);
  --gradient-surface: linear-gradient(135deg, var(--surface) 0%, var(--surface-light) 100%);
  
  /* Spacing Scale */
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 1.5rem;
  --space-lg: 2rem;
  --space-xl: 3rem;
  --space-2xl: 4rem;
  --space-3xl: 6rem;
  
  /* Typography Scale */
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 2rem;
  --font-size-4xl: 2.5rem;
  --font-size-5xl: 3rem;
  --font-size-6xl: 4rem;
  
  /* Font Weights */
  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;
  
  /* Line Heights */
  --line-height-tight: 1.2;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.75;
  
  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.5rem;
  --radius-full: 9999px;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.6);
  --shadow-glow: 0 0 20px rgba(0, 255, 255, 0.3);
  
  /* Transitions */
  --transition-fast: 150ms ease-in-out;
  --transition-base: 250ms ease-in-out;
  --transition-slow: 350ms ease-in-out;
  
  /* Z-index Scale */
  --z-base: 1;
  --z-dropdown: 100;
  --z-sticky: 200;
  --z-fixed: 300;
  --z-modal: 400;
  --z-tooltip: 500;
  
  /* Container Widths */
  --container-sm: 640px;
  --container-md: 768px;
  --container-lg: 1024px;
  --container-xl: 1280px;
  --container-2xl: 1536px;
}

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

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-normal);
  line-height: var(--line-height-normal);
  color: var(--text-primary);
  background-color: var(--background);
  background-image: 
    radial-gradient(at 0% 0%, hsla(190, 95%, 50%, 0.1) 0px, transparent 50%),
    radial-gradient(at 100% 100%, hsla(280, 85%, 60%, 0.1) 0px, transparent 50%);
  background-attachment: fixed;
  min-height: 100vh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ============================================
   TYPOGRAPHY
   ============================================ */
h1, h2, h3, h4, h5, h6 {
  font-weight: var(--font-weight-bold);
  line-height: var(--line-height-tight);
  margin-bottom: var(--space-md);
  color: var(--text-primary);
}

h1 {
  font-size: var(--font-size-5xl);
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

h2 {
  font-size: var(--font-size-4xl);
}

h3 {
  font-size: var(--font-size-3xl);
}

h4 {
  font-size: var(--font-size-2xl);
}

h5 {
  font-size: var(--font-size-xl);
}

h6 {
  font-size: var(--font-size-lg);
}

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

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

a:hover {
  color: var(--primary-light);
}

strong {
  font-weight: var(--font-weight-bold);
  color: var(--text-primary);
}

/* ============================================
   LAYOUT COMPONENTS
   ============================================ */
.container {
  width: 100%;
  max-width: var(--container-xl);
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

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

.section-title {
  text-align: center;
  margin-bottom: var(--space-2xl);
}

/* ============================================
   NAVIGATION
   ============================================ */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: var(--z-fixed);
  background: rgba(28, 32, 43, 0.8);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  transition: all var(--transition-base);
}

.navbar.scrolled {
  background: rgba(28, 32, 43, 0.95);
  box-shadow: var(--shadow-lg);
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--space-md) var(--space-lg);
  max-width: var(--container-2xl);
  margin: 0 auto;
}

.nav-logo {
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-bold);
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  transition: transform var(--transition-base);
}

.nav-logo:hover {
  transform: scale(1.05);
}

.nav-menu {
  display: flex;
  gap: var(--space-lg);
  list-style: none;
  align-items: center;
}

.nav-link {
  color: var(--text-secondary);
  font-weight: var(--font-weight-medium);
  padding: var(--space-xs) var(--space-sm);
  border-radius: var(--radius-md);
  transition: all var(--transition-base);
  position: relative;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 0;
  height: 2px;
  background: var(--gradient-primary);
  transition: width var(--transition-base);
}

.nav-link:hover {
  color: var(--text-primary);
}

.nav-link:hover::after,
.nav-link.active::after {
  width: 80%;
}

.nav-link.active {
  color: var(--primary);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 4px;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-xs);
}

.nav-toggle span {
  width: 25px;
  height: 3px;
  background: var(--text-primary);
  border-radius: var(--radius-full);
  transition: all var(--transition-base);
}

/* ============================================
   GLASSMORPHIC CARDS
   ============================================ */
.glass-card {
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-xl);
  padding: var(--space-lg);
  transition: all var(--transition-base);
  box-shadow: var(--shadow-md);
}

.glass-card:hover {
  background: rgba(255, 255, 255, 0.08);
  border-color: rgba(0, 255, 255, 0.3);
  box-shadow: var(--shadow-xl), var(--shadow-glow);
  transform: translateY(-5px);
}

.glass-card-header {
  margin-bottom: var(--space-md);
}

.glass-card-title {
  font-size: var(--font-size-xl);
  margin-bottom: var(--space-xs);
}

.glass-card-subtitle {
  color: var(--text-muted);
  font-size: var(--font-size-sm);
}

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

/* ============================================
   BUTTONS
   ============================================ */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  padding: var(--space-sm) var(--space-lg);
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-semibold);
  border: none;
  border-radius: var(--radius-lg);
  cursor: pointer;
  transition: all var(--transition-base);
  text-decoration: none;
  position: relative;
  overflow: hidden;
}

.btn::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 0;
  height: 0;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.2);
  transform: translate(-50%, -50%);
  transition: width var(--transition-slow), height var(--transition-slow);
}

.btn:hover::before {
  width: 300px;
  height: 300px;
}

.btn-primary {
  background: var(--gradient-primary);
  color: white;
  box-shadow: var(--shadow-md);
}

.btn-primary:hover {
  box-shadow: var(--shadow-lg), var(--shadow-glow);
  transform: translateY(-2px);
}

.btn-secondary {
  background: transparent;
  color: var(--primary);
  border: 2px solid var(--primary);
}

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

.btn-ghost {
  background: transparent;
  color: var(--text-primary);
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.btn-ghost:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: var(--primary);
}

/* ============================================
   GRID SYSTEM
   ============================================ */
.grid {
  display: grid;
  gap: var(--space-lg);
}

.grid-cols-1 { grid-template-columns: repeat(1, 1fr); }
.grid-cols-2 { grid-template-columns: repeat(2, 1fr); }
.grid-cols-3 { grid-template-columns: repeat(3, 1fr); }
.grid-cols-4 { grid-template-columns: repeat(4, 1fr); }

/* ============================================
   BADGES & TAGS
   ============================================ */
.badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  padding: var(--space-xs) var(--space-sm);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-semibold);
  border-radius: var(--radius-full);
  background: rgba(0, 255, 255, 0.1);
  color: var(--primary);
  border: 1px solid rgba(0, 255, 255, 0.3);
  transition: all var(--transition-base);
}

.badge:hover {
  background: rgba(0, 255, 255, 0.2);
  transform: scale(1.05);
}

.badge-success {
  background: rgba(34, 197, 94, 0.1);
  color: var(--success);
  border-color: rgba(34, 197, 94, 0.3);
}

.badge-warning {
  background: rgba(255, 193, 7, 0.1);
  color: var(--warning);
  border-color: rgba(255, 193, 7, 0.3);
}

/* ============================================
   STATS CARDS
   ============================================ */
.stat-card {
  text-align: center;
  padding: var(--space-lg);
}

.stat-value {
  font-size: var(--font-size-4xl);
  font-weight: var(--font-weight-bold);
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: var(--space-xs);
}

.stat-label {
  color: var(--text-muted);
  font-size: var(--font-size-sm);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* ============================================
   TIMELINE
   ============================================ */
.timeline {
  position: relative;
  padding-left: var(--space-xl);
}

.timeline::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--gradient-primary);
}

.timeline-item {
  position: relative;
  margin-bottom: var(--space-xl);
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: calc(-1 * var(--space-xl) - 6px);
  top: 0;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--primary);
  border: 3px solid var(--background);
  box-shadow: 0 0 0 2px var(--primary);
}

.timeline-date {
  color: var(--primary);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-semibold);
  margin-bottom: var(--space-xs);
}

.timeline-content {
  background: rgba(255, 255, 255, 0.05);
  padding: var(--space-lg);
  border-radius: var(--radius-lg);
  border-left: 3px solid var(--primary);
}

/* ============================================
   FOOTER
   ============================================ */
.footer {
  background: var(--surface);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding: var(--space-2xl) 0 var(--space-lg);
  margin-top: var(--space-3xl);
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--space-xl);
  margin-bottom: var(--space-xl);
}

.footer-section h4 {
  margin-bottom: var(--space-md);
  color: var(--primary);
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.footer-links a {
  color: var(--text-secondary);
  transition: all var(--transition-base);
}

.footer-links a:hover {
  color: var(--primary);
  padding-left: var(--space-xs);
}

.footer-bottom {
  text-align: center;
  padding-top: var(--space-lg);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  color: var(--text-muted);
  font-size: var(--font-size-sm);
}

/* ============================================
   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 slideInRight {
  from {
    opacity: 0;
    transform: translateX(30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

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

.animate-fade-in {
  animation: fadeIn 0.6s ease-out forwards;
}

.animate-slide-in-left {
  animation: slideInLeft 0.6s ease-out forwards;
}

.animate-slide-in-right {
  animation: slideInRight 0.6s ease-out forwards;
}

/* ============================================
   RESPONSIVE DESIGN
   ============================================ */
@media (max-width: 768px) {
  :root {
    --font-size-5xl: 2.5rem;
    --font-size-4xl: 2rem;
    --font-size-3xl: 1.75rem;
  }
  
  .nav-menu {
    position: fixed;
    top: 70px;
    left: -100%;
    width: 100%;
    height: calc(100vh - 70px);
    background: rgba(28, 32, 43, 0.98);
    backdrop-filter: blur(20px);
    flex-direction: column;
    justify-content: flex-start;
    padding: var(--space-xl);
    transition: left var(--transition-base);
  }
  
  .nav-menu.active {
    left: 0;
  }
  
  .nav-toggle {
    display: flex;
  }
  
  .nav-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
  }
  
  .nav-toggle.active span:nth-child(2) {
    opacity: 0;
  }
  
  .nav-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(7px, -6px);
  }
  
  .grid-cols-2,
  .grid-cols-3,
  .grid-cols-4 {
    grid-template-columns: 1fr;
  }
  
  .section {
    padding: var(--space-2xl) 0;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 var(--space-md);
  }
  
  h1 {
    font-size: var(--font-size-4xl);
  }
}

/* ============================================
   UTILITY CLASSES
   ============================================ */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mt-sm { margin-top: var(--space-sm); }
.mt-md { margin-top: var(--space-md); }
.mt-lg { margin-top: var(--space-lg); }
.mt-xl { margin-top: var(--space-xl); }

.mb-sm { margin-bottom: var(--space-sm); }
.mb-md { margin-bottom: var(--space-md); }
.mb-lg { margin-bottom: var(--space-lg); }
.mb-xl { margin-bottom: var(--space-xl); }

.gradient-text {
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.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-sm { gap: var(--space-sm); }
.gap-md { gap: var(--space-md); }
.gap-lg { gap: var(--space-lg); }