/* ===================================
   NEO GLOW DESIGN SYSTEM
   Levko Kravchuk Portfolio
   =================================== */

/* CSS Variables */
:root {
  /* Colors */
  --bg-primary: #0a0a1a;
  --bg-secondary: #1a1a3e;
  --bg-card: rgba(26, 26, 62, 0.6);
  --neon-cyan: #00fff7;
  --neon-magenta: #ff00ff;
  --neon-purple: #bf00ff;
  --neon-blue: #00d4ff;
  --text-primary: #ffffff;
  --text-secondary: rgba(255, 255, 255, 0.7);
  --text-muted: rgba(255, 255, 255, 0.5);

  /* Glow Effects */
  --glow-cyan: 0 0 10px var(--neon-cyan), 0 0 20px var(--neon-cyan), 0 0 40px var(--neon-cyan);
  --glow-magenta: 0 0 10px var(--neon-magenta), 0 0 20px var(--neon-magenta), 0 0 40px var(--neon-magenta);
  --glow-purple: 0 0 10px var(--neon-purple), 0 0 20px var(--neon-purple), 0 0 40px var(--neon-purple);
  --glow-text: 0 0 10px currentColor, 0 0 20px currentColor;

  /* Glassmorphism */
  --glass-bg: rgba(255, 255, 255, 0.05);
  --glass-border: rgba(255, 255, 255, 0.1);
  --glass-blur: blur(10px);

  /* Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --spacing-xxl: 5rem;

  /* Typography */
  --font-main: 'Inter', 'Segoe UI', sans-serif;
  --font-display: 'Outfit', 'Inter', sans-serif;

  /* Transitions */
  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-main);
  background: linear-gradient(135deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
  background-attachment: fixed;
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
}

/* Animated Background Stars */
body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-image:
    radial-gradient(2px 2px at 20px 30px, var(--neon-cyan), transparent),
    radial-gradient(2px 2px at 40px 70px, var(--neon-magenta), transparent),
    radial-gradient(1px 1px at 90px 40px, var(--text-primary), transparent),
    radial-gradient(2px 2px at 160px 120px, var(--neon-purple), transparent),
    radial-gradient(1px 1px at 230px 80px, var(--neon-cyan), transparent),
    radial-gradient(2px 2px at 300px 150px, var(--text-primary), transparent),
    radial-gradient(1px 1px at 350px 200px, var(--neon-magenta), transparent);
  background-size: 400px 300px;
  opacity: 0.4;
  animation: twinkle 8s ease-in-out infinite;
  pointer-events: none;
  z-index: -1;
}

@keyframes twinkle {

  0%,
  100% {
    opacity: 0.4;
  }

  50% {
    opacity: 0.6;
  }
}

/* Typography */
h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--spacing-sm);
}

h1 {
  font-size: clamp(2.5rem, 5vw, 4rem);
  background: linear-gradient(135deg, var(--neon-cyan), var(--neon-magenta));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  text-shadow: none;
}

h2 {
  font-size: clamp(1.8rem, 3vw, 2.5rem);
  color: var(--neon-cyan);
  text-shadow: var(--glow-text);
}

h3 {
  font-size: clamp(1.3rem, 2vw, 1.8rem);
  color: var(--text-primary);
}

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

a {
  color: var(--neon-cyan);
  text-decoration: none;
  transition: var(--transition-normal);
}

a:hover {
  color: var(--neon-magenta);
  text-shadow: var(--glow-text);
}

/* Container */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

/* Navigation */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(10, 10, 26, 0.9);
  backdrop-filter: var(--glass-blur);
  border-bottom: 1px solid var(--glass-border);
  padding: var(--spacing-sm) 0;
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

.nav-logo {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--neon-cyan), var(--neon-magenta));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-menu {
  display: flex;
  list-style: none;
  gap: var(--spacing-md);
}

.nav-link {
  color: var(--text-secondary);
  font-weight: 500;
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: 8px;
  transition: var(--transition-normal);
  position: relative;
  min-width: 85px;
  text-align: center;
  white-space: nowrap;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  width: 0;
  height: 2px;
  background: var(--neon-cyan);
  box-shadow: var(--glow-cyan);
  transition: var(--transition-normal);
  transform: translateX(-50%);
}

.nav-link:hover,
.nav-link.active {
  color: var(--neon-cyan);
  text-shadow: var(--glow-text);
}

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

/* Mobile Menu Toggle */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 10px;
}

.nav-toggle span {
  width: 25px;
  height: 3px;
  background: var(--neon-cyan);
  border-radius: 3px;
  transition: var(--transition-normal);
  box-shadow: 0 0 5px var(--neon-cyan);
}

/* Glass Card */
.glass-card {
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  border-radius: 20px;
  padding: var(--spacing-lg);
  transition: var(--transition-normal);
}

.glass-card:hover {
  border-color: var(--neon-cyan);
  box-shadow: 0 0 30px rgba(0, 255, 247, 0.1);
  transform: translateY(-5px);
}

/* Neon Button */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-sm) var(--spacing-lg);
  font-family: var(--font-main);
  font-weight: 600;
  font-size: 1rem;
  border: 2px solid var(--neon-cyan);
  border-radius: 50px;
  background: transparent;
  color: var(--neon-cyan);
  cursor: pointer;
  transition: var(--transition-normal);
  text-decoration: none;
}

.btn:hover {
  background: var(--neon-cyan);
  color: var(--bg-primary);
  box-shadow: var(--glow-cyan);
  text-shadow: none;
}

.btn-magenta {
  border-color: var(--neon-magenta);
  color: var(--neon-magenta);
}

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

/* Hero Section */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-xxl) var(--spacing-md);
  text-align: center;
}

.hero-content {
  max-width: 1000px;
}

.hero-avatar {
  width: 180px;
  height: 180px;
  border-radius: 50%;
  object-fit: cover;
  border: 3px solid var(--neon-cyan);
  box-shadow: var(--glow-cyan);
  margin-bottom: var(--spacing-lg);
  animation: pulse-glow 3s ease-in-out infinite;
}

@keyframes pulse-glow {

  0%,
  100% {
    box-shadow: 0 0 20px var(--neon-cyan), 0 0 40px var(--neon-cyan);
  }

  50% {
    box-shadow: 0 0 30px var(--neon-magenta), 0 0 60px var(--neon-magenta);
  }
}

.hero-title {
  margin-bottom: var(--spacing-sm);
}

.hero-subtitle {
  font-size: 1.3rem;
  color: var(--text-secondary);
  margin-bottom: var(--spacing-lg);
}

.hero-buttons {
  display: flex;
  gap: var(--spacing-sm);
  justify-content: center;
  flex-wrap: wrap;
}

/* Section */
.section {
  padding: var(--spacing-xxl) 0;
}

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

/* Page Cards Grid */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--spacing-lg);
}

.page-card {
  text-align: center;
  padding: var(--spacing-xl);
}

.page-card-icon {
  font-size: 3rem;
  margin-bottom: var(--spacing-md);
  display: block;
}

.page-card h3 {
  color: var(--neon-cyan);
  margin-bottom: var(--spacing-sm);
}

.page-card p {
  margin-bottom: var(--spacing-md);
}

/* Timeline */
.timeline {
  position: relative;
  max-width: 800px;
  margin: 0 auto;
  padding-left: var(--spacing-xl);
}

.timeline::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: linear-gradient(to bottom, var(--neon-cyan), var(--neon-magenta), var(--neon-purple));
  box-shadow: 0 0 10px var(--neon-cyan);
  border-radius: 3px;
}

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

.timeline-item::before {
  content: '';
  position: absolute;
  left: calc(-1 * var(--spacing-xl) - 6px);
  top: 10px;
  width: 15px;
  height: 15px;
  background: var(--neon-cyan);
  border-radius: 50%;
  box-shadow: var(--glow-cyan);
}

.timeline-date {
  font-size: 0.9rem;
  color: var(--neon-magenta);
  font-weight: 600;
  margin-bottom: var(--spacing-xs);
}

.timeline-title {
  font-size: 1.3rem;
  margin-bottom: var(--spacing-xs);
}

.timeline-company {
  color: var(--neon-cyan);
  font-weight: 500;
  margin-bottom: var(--spacing-sm);
}

/* Certificates Grid */
.certs-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--spacing-lg);
}

.cert-card {
  text-align: center;
  padding: var(--spacing-lg);
}

.cert-card img {
  max-width: 100%;
  height: auto;
  border-radius: 10px;
  margin-bottom: var(--spacing-md);
  transition: var(--transition-normal);
}

.cert-card:hover img {
  box-shadow: 0 0 30px rgba(0, 255, 247, 0.3);
}

.cert-card h4 {
  color: var(--neon-cyan);
  margin-bottom: var(--spacing-xs);
}

/* Contact Info */
.contact-list {
  list-style: none;
}

.contact-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-sm);
  padding: var(--spacing-sm);
  border-radius: 10px;
  transition: var(--transition-normal);
}

.contact-item:hover {
  background: var(--glass-bg);
}

.contact-icon {
  font-size: 1.5rem;
  color: var(--neon-cyan);
  width: 40px;
  text-align: center;
}

/* Skills */
.skills-list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-xs);
}

.skill-tag {
  display: inline-block;
  padding: var(--spacing-xs) var(--spacing-sm);
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: 20px;
  font-size: 0.9rem;
  color: var(--text-secondary);
  transition: var(--transition-normal);
}

.skill-tag:hover {
  border-color: var(--neon-cyan);
  color: var(--neon-cyan);
  box-shadow: 0 0 15px rgba(0, 255, 247, 0.2);
}

/* Footer */
.footer {
  text-align: center;
  padding: var(--spacing-xl) var(--spacing-md);
  border-top: 1px solid var(--glass-border);
  margin-top: var(--spacing-xxl);
}

.footer-text {
  color: var(--text-muted);
  font-size: 0.9rem;
}

.footer-text a {
  color: var(--neon-cyan);
}

/* Back to Top */
.back-to-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 50px;
  height: 50px;
  border-radius: 50%;
  background: var(--bg-secondary);
  border: 2px solid var(--neon-cyan);
  color: var(--neon-cyan);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transition: var(--transition-normal);
  z-index: 999;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  background: var(--neon-cyan);
  color: var(--bg-primary);
  box-shadow: var(--glow-cyan);
}

/* Page Header */
.page-header {
  padding-top: 120px;
  padding-bottom: var(--spacing-xl);
  text-align: center;
}

.page-content {
  padding-bottom: var(--spacing-xxl);
}

/* Placeholder Content */
.placeholder-content {
  text-align: center;
  padding: var(--spacing-xxl);
  color: var(--text-muted);
}

.placeholder-content .icon {
  font-size: 4rem;
  margin-bottom: var(--spacing-lg);
  opacity: 0.5;
}

/* Responsive */
@media (max-width: 768px) {
  .nav-container {
    flex-wrap: wrap;
  }

  .nav-menu {
    position: fixed;
    top: 60px;
    left: 0;
    right: 0;
    background: rgba(10, 10, 26, 0.98);
    flex-direction: column;
    align-items: center;
    padding: var(--spacing-lg);
    gap: var(--spacing-sm);
    transform: translateY(-150%);
    opacity: 0;
    transition: var(--transition-normal);
    max-height: calc(100vh - 60px);
    overflow-y: auto;
  }

  .nav-menu.active {
    transform: translateY(0);
    opacity: 1;
  }

  .nav-toggle {
    display: flex;
  }

  .nav-right {
    order: 2;
    margin-right: 10px;
  }

  .hero {
    padding-top: 100px;
    padding-left: var(--spacing-sm);
    padding-right: var(--spacing-sm);
  }

  .hero-avatar {
    width: 140px;
    height: 140px;
  }

  .hero-subtitle {
    font-size: 1.1rem;
    padding: 0 10px;
  }

  .hero-buttons {
    flex-direction: column;
    align-items: center;
  }

  .hero-buttons .btn {
    width: 100%;
    max-width: 250px;
    justify-content: center;
  }

  .timeline {
    padding-left: var(--spacing-lg);
  }

  .timeline-item::before {
    left: calc(-1 * var(--spacing-lg) - 6px);
  }

  .cards-grid {
    grid-template-columns: 1fr;
  }

  .certs-grid {
    grid-template-columns: 1fr;
  }

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

  .page-header {
    padding-top: 100px;
  }

  .container {
    padding: 0 var(--spacing-sm);
  }

  .glass-card {
    padding: var(--spacing-md);
  }

  .back-to-top {
    bottom: 20px;
    right: 20px;
    width: 45px;
    height: 45px;
  }
}

/* Small mobile screens */
@media (max-width: 480px) {
  h1 {
    font-size: 2rem;
  }

  h2 {
    font-size: 1.5rem;
  }

  .nav-logo {
    font-size: 1.3rem;
  }

  .hero-avatar {
    width: 120px;
    height: 120px;
  }

  .btn {
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: 0.9rem;
  }
}

/* Language Switcher */
.lang-switcher {
  display: flex;
  gap: 4px;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: 25px;
  padding: 4px;
}

.lang-btn {
  padding: 6px 12px;
  border: none;
  background: transparent;
  color: var(--text-secondary);
  font-family: var(--font-main);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  border-radius: 20px;
  transition: var(--transition-fast);
}

.lang-btn:hover {
  color: var(--text-primary);
}

.lang-btn.active {
  background: var(--neon-cyan);
  color: var(--bg-primary);
  box-shadow: 0 0 10px rgba(0, 255, 247, 0.3);
}

.nav-right {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

/* Touch-friendly mobile improvements */
@media (hover: none) and (pointer: coarse) {
  .nav-link {
    padding: var(--spacing-sm) var(--spacing-md);
  }

  .btn {
    min-height: 48px;
  }

  .lang-btn {
    min-height: 40px;
    padding: 8px 16px;
  }

  .contact-item {
    min-height: 48px;
  }

  .skill-tag {
    padding: var(--spacing-sm) var(--spacing-md);
  }
}

/* Print Styles */
@media print {
  body {
    background: white;
    color: black;
  }

  .nav,
  .back-to-top,
  .lang-switcher {
    display: none;
  }

  .glass-card {
    border: 1px solid #ddd;
    box-shadow: none;
  }
}