/* ==========================================================================
   Design System & Global Variables
   ========================================================================== */
:root {
  /* Color Palette - Dark Theme (Default) */
  --bg-primary: #0a0c16;
  --bg-secondary: #121526;
  --bg-card: rgba(22, 27, 46, 0.65);
  --bg-card-hover: rgba(30, 36, 62, 0.85);
  
  --text-primary: #f0f3fe;
  --text-secondary: #a0aec0;
  --text-muted: #64748b;
  
  --accent-purple: #8b5cf6;
  --accent-cyan: #06b6d4;
  --accent-pink: #ec4899;
  --accent-blue: #3b82f6;

  --gradient-primary: linear-gradient(135deg, #8b5cf6 0%, #06b6d4 100%);
  --gradient-hover: linear-gradient(135deg, #a78bfa 0%, #22d3ee 100%);
  --gradient-glow: linear-gradient(135deg, rgba(139, 92, 246, 0.4), rgba(6, 182, 212, 0.4));
  --border-glass: rgba(255, 255, 255, 0.1);
  --border-glow: rgba(139, 92, 246, 0.5);

  --shadow-glass: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
  --shadow-neon: 0 0 20px rgba(139, 92, 246, 0.35);

  --font-main: 'Inter', 'Noto Sans KR', sans-serif;
  --font-heading: 'Outfit', 'Noto Sans KR', sans-serif;

  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-full: 9999px;

  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Light Theme Overrides */
[data-theme="light"] {
  --bg-primary: #f8fafc;
  --bg-secondary: #edf2f7;
  --bg-card: rgba(255, 255, 255, 0.75);
  --bg-card-hover: rgba(255, 255, 255, 0.95);
  
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;

  --border-glass: rgba(0, 0, 0, 0.08);
  --shadow-glass: 0 8px 32px 0 rgba(31, 38, 135, 0.07);
}

/* Base Styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

body {
  background-color: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font-main);
  line-height: 1.6;
  overflow-x: hidden;
  position: relative;
  transition: background-color var(--transition-normal), color var(--transition-normal);
}

/* Scrollbar */
::-webkit-scrollbar {
  width: 10px;
}
::-webkit-scrollbar-track {
  background: var(--bg-primary);
}
::-webkit-scrollbar-thumb {
  background: var(--bg-card);
  border-radius: var(--radius-full);
  border: 2px solid var(--bg-primary);
}
::-webkit-scrollbar-thumb:hover {
  background: var(--accent-purple);
}

/* Typography & Utilities */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.2;
}

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

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

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
}

.section-padding {
  padding: 6rem 0;
}

.text-center {
  text-align: center;
}

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

/* Glassmorphism Card Style */
.glass-card {
  background: var(--bg-card);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-glass);
  transition: transform var(--transition-normal), border-color var(--transition-normal), box-shadow var(--transition-normal);
}

.glass-card:hover {
  border-color: var(--border-glow);
  box-shadow: var(--shadow-neon);
}

/* Background Ambient Glows */
.ambient-glow {
  position: fixed;
  border-radius: 50%;
  filter: blur(140px);
  pointer-events: none;
  z-index: -1;
  opacity: 0.45;
}

.glow-1 {
  width: 500px;
  height: 500px;
  background: var(--accent-purple);
  top: -100px;
  left: -100px;
}

.glow-2 {
  width: 450px;
  height: 450px;
  background: var(--accent-cyan);
  top: 40%;
  right: -100px;
}

.glow-3 {
  width: 600px;
  height: 600px;
  background: var(--accent-pink);
  bottom: -150px;
  left: 20%;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.6rem;
  padding: 0.8rem 1.6rem;
  font-family: var(--font-heading);
  font-weight: 600;
  border-radius: var(--radius-full);
  cursor: pointer;
  border: none;
  transition: all var(--transition-normal);
}

.btn-primary {
  background: var(--gradient-primary);
  color: #fff;
  box-shadow: 0 4px 15px rgba(139, 92, 246, 0.4);
}

.btn-primary:hover {
  background: var(--gradient-hover);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(139, 92, 246, 0.6);
}

.btn-glass {
  background: rgba(255, 255, 255, 0.08);
  backdrop-filter: blur(8px);
  border: 1px solid var(--border-glass);
  color: var(--text-primary);
}

.btn-glass:hover {
  background: rgba(255, 255, 255, 0.15);
  border-color: var(--accent-purple);
  transform: translateY(-2px);
}

.btn-lg {
  padding: 1rem 2rem;
  font-size: 1.05rem;
}

.btn-sm {
  padding: 0.5rem 1rem;
  font-size: 0.9rem;
}

.btn-block {
  width: 100%;
}

.icon-btn {
  background: var(--bg-card);
  border: 1px solid var(--border-glass);
  color: var(--text-primary);
  width: 44px;
  height: 44px;
  border-radius: var(--radius-full);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.icon-btn:hover {
  border-color: var(--accent-cyan);
  color: var(--accent-cyan);
  transform: scale(1.05);
}

/* Grid Layouts */
.grid {
  display: grid;
  gap: 2rem;
}

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

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

/* Header & Navigation */
.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  padding: 1.2rem 0;
  transition: all var(--transition-normal);
}

.header.scrolled {
  background: rgba(10, 12, 22, 0.85);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-glass);
  padding: 0.8rem 0;
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  font-family: var(--font-heading);
  font-size: 1.6rem;
  font-weight: 800;
  letter-spacing: -0.5px;
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.logo-accent {
  color: var(--accent-cyan);
}

.online-indicator {
  width: 8px;
  height: 8px;
  background-color: #10b981;
  border-radius: 50%;
  box-shadow: 0 0 10px #10b981;
}

.nav-menu {
  display: flex;
  list-style: none;
  gap: 2rem;
}

.nav-link {
  color: var(--text-secondary);
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.95rem;
  position: relative;
  padding: 0.4rem 0;
}

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

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

.nav-link:hover::after, .nav-link.active::after {
  width: 100%;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.mobile-menu-btn {
  display: none;
}

/* Section Header */
.section-header {
  margin-bottom: 3.5rem;
}

.section-subtitle {
  color: var(--accent-cyan);
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 2px;
  text-transform: uppercase;
  display: block;
  margin-bottom: 0.5rem;
}

.section-title {
  font-size: 2.3rem;
  margin-bottom: 0.8rem;
}

.section-desc {
  color: var(--text-secondary);
  font-size: 1.1rem;
}

/* Hero Section */
.hero-section {
  min-height: 100vh;
  padding-top: 9rem;
  padding-bottom: 4rem;
  display: flex;
  align-items: center;
  position: relative;
}

.hero-container {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 3rem;
  align-items: center;
}

.status-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.4rem 1rem;
  background: rgba(139, 92, 246, 0.15);
  border: 1px solid rgba(139, 92, 246, 0.3);
  border-radius: var(--radius-full);
  font-size: 0.88rem;
  color: var(--accent-purple);
  margin-bottom: 1.5rem;
}

.pulse-dot {
  width: 8px;
  height: 8px;
  background-color: var(--accent-purple);
  border-radius: 50%;
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0% { box-shadow: 0 0 0 0 rgba(139, 92, 246, 0.7); }
  70% { box-shadow: 0 0 0 10px rgba(139, 92, 246, 0); }
  100% { box-shadow: 0 0 0 0 rgba(139, 92, 246, 0); }
}

.hero-title {
  font-size: 3.2rem;
  line-height: 1.2;
  margin-bottom: 1.2rem;
}

.highlight-name {
  color: var(--accent-cyan);
  text-decoration: underline;
  text-decoration-color: rgba(6, 182, 212, 0.4);
}

.hero-description {
  color: var(--text-secondary);
  font-size: 1.15rem;
  margin-bottom: 2rem;
}

.hero-cta {
  display: flex;
  gap: 1rem;
  margin-bottom: 3rem;
  flex-wrap: wrap;
}

.hero-stats {
  display: flex;
  align-items: center;
  gap: 2rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border-glass);
}

.stat-item {
  display: flex;
  flex-direction: column;
}

.stat-number {
  font-family: var(--font-heading);
  font-size: 2.2rem;
  font-weight: 800;
  color: var(--text-primary);
  display: inline-block;
}

.stat-plus {
  font-size: 1.4rem;
  color: var(--accent-cyan);
}

.stat-label {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.stat-divider {
  width: 1px;
  height: 40px;
  background: var(--border-glass);
}

/* 3D Tilt Card (Hero Visual) */
.hero-visual {
  perspective: 1000px;
  display: flex;
  justify-content: center;
}

.tilt-card {
  width: 100%;
  max-width: 380px;
  background: var(--bg-card);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-lg);
  padding: 1.8rem;
  backdrop-filter: blur(20px);
  box-shadow: var(--shadow-glass);
  transform-style: preserve-3d;
  transition: transform 0.1s ease-out;
  position: relative;
}

.card-glow {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  border-radius: var(--radius-lg);
  background: var(--gradient-glow);
  filter: blur(25px);
  z-index: -1;
  opacity: 0.6;
}

.profile-image-wrapper {
  position: relative;
  border-radius: var(--radius-md);
  overflow: hidden;
  margin-bottom: 1.5rem;
  border: 2px solid var(--border-glass);
}

.profile-img {
  width: 100%;
  height: 320px;
  object-fit: cover;
  transition: transform var(--transition-slow);
}

.tilt-card:hover .profile-img {
  transform: scale(1.05);
}

.profile-badge {
  position: absolute;
  bottom: 12px;
  right: 12px;
  background: rgba(10, 12, 22, 0.85);
  backdrop-filter: blur(8px);
  border: 1px solid var(--border-glass);
  padding: 0.4rem 0.8rem;
  border-radius: var(--radius-full);
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--accent-cyan);
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.profile-info h3 {
  font-size: 1.4rem;
  margin-bottom: 0.2rem;
}

.role-text {
  color: var(--accent-purple);
  font-size: 0.95rem;
  margin-bottom: 1.2rem;
}

.social-links {
  display: flex;
  gap: 0.8rem;
}

.social-icon {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-glass);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
  font-size: 1.1rem;
}

.social-icon:hover {
  background: var(--gradient-primary);
  color: #fff;
  border-color: transparent;
  transform: translateY(-3px);
}

/* About Section */
.value-card {
  padding: 2.5rem 1.8rem;
  text-align: center;
}

.value-icon {
  width: 65px;
  height: 65px;
  border-radius: var(--radius-md);
  background: var(--gradient-glow);
  border: 1px solid var(--border-glow);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 1.8rem;
  color: var(--accent-cyan);
  margin-bottom: 1.5rem;
}

.value-card h3 {
  font-size: 1.3rem;
  margin-bottom: 0.8rem;
}

.value-card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
}

/* Timeline */
.timeline-container {
  margin-top: 5rem;
}

.timeline-title {
  font-size: 1.8rem;
  margin-bottom: 3rem;
  color: var(--text-primary);
}

.timeline {
  position: relative;
  max-width: 800px;
  margin: 0 auto;
}

.timeline::before {
  content: '';
  position: absolute;
  top: 0;
  bottom: 0;
  left: 20px;
  width: 2px;
  background: var(--border-glass);
}

.timeline-item {
  position: relative;
  padding-left: 60px;
  margin-bottom: 2.5rem;
}

.timeline-dot {
  position: absolute;
  left: 13px;
  top: 15px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--accent-cyan);
  box-shadow: 0 0 12px var(--accent-cyan);
  border: 3px solid var(--bg-primary);
}

.timeline-content {
  padding: 1.8rem;
}

.timeline-date {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--accent-purple);
  text-transform: uppercase;
  margin-bottom: 0.4rem;
  display: block;
}

.timeline-content h4 {
  font-size: 1.25rem;
  margin-bottom: 0.2rem;
}

.timeline-content .company {
  color: var(--text-secondary);
  font-weight: 600;
  margin-bottom: 0.8rem;
}

.timeline-content .desc {
  color: var(--text-secondary);
  font-size: 0.95rem;
}

/* Skills Section */
.skills-wrapper {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2rem;
  margin-bottom: 3rem;
}

.skill-category {
  padding: 2.2rem;
}

.skill-category h3 {
  font-size: 1.3rem;
  margin-bottom: 1.8rem;
  display: flex;
  align-items: center;
  gap: 0.6rem;
  color: var(--accent-cyan);
}

.skill-list {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.skill-info {
  display: flex;
  justify-content: space-between;
  margin-bottom: 0.5rem;
  font-weight: 600;
  font-size: 0.95rem;
}

.skill-percent {
  color: var(--accent-purple);
}

.progress-bar {
  width: 100%;
  height: 8px;
  background: rgba(255, 255, 255, 0.08);
  border-radius: var(--radius-full);
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: var(--gradient-primary);
  border-radius: var(--radius-full);
  transition: width 1.5s cubic-bezier(0.1, 0.5, 0.1, 1);
}

.tech-tags-cloud {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 1rem;
}

.tech-tag {
  background: var(--bg-card);
  border: 1px solid var(--border-glass);
  padding: 0.6rem 1.4rem;
  border-radius: var(--radius-full);
  font-weight: 500;
  font-size: 0.95rem;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
  transition: all var(--transition-fast);
}

.tech-tag:hover {
  border-color: var(--accent-purple);
  color: var(--text-primary);
  transform: translateY(-3px);
  box-shadow: var(--shadow-neon);
}

/* Projects Section */
.project-filters {
  display: flex;
  justify-content: center;
  gap: 0.8rem;
  margin-bottom: 3rem;
  flex-wrap: wrap;
}

.filter-btn {
  background: var(--bg-card);
  border: 1px solid var(--border-glass);
  color: var(--text-secondary);
  padding: 0.6rem 1.5rem;
  border-radius: var(--radius-full);
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.filter-btn:hover, .filter-btn.active {
  background: var(--gradient-primary);
  color: #fff;
  border-color: transparent;
  box-shadow: 0 4px 15px rgba(139, 92, 246, 0.3);
}

.project-card {
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.project-thumb {
  position: relative;
  height: 250px;
  overflow: hidden;
}

.project-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition-slow);
}

.project-card:hover .project-thumb img {
  transform: scale(1.08);
}

.project-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(10, 12, 22, 0.7);
  backdrop-filter: blur(6px);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transition: opacity var(--transition-normal);
}

.project-card:hover .project-overlay {
  opacity: 1;
}

.project-content {
  padding: 1.8rem;
  display: flex;
  flex-direction: column;
  flex: 1;
}

.project-tags {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 0.8rem;
  flex-wrap: wrap;
}

.tag {
  background: rgba(139, 92, 246, 0.15);
  color: var(--accent-cyan);
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.2rem 0.6rem;
  border-radius: var(--radius-sm);
}

.project-content h3 {
  font-size: 1.4rem;
  margin-bottom: 0.6rem;
}

.project-content p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-bottom: 1.5rem;
  flex: 1;
}

.project-links {
  display: flex;
  gap: 1.2rem;
  border-top: 1px solid var(--border-glass);
  padding-top: 1rem;
}

.link-btn {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.link-btn:hover {
  color: var(--accent-cyan);
}

/* Contact Section */
.contact-info-card, .contact-form-card {
  padding: 2.8rem;
}

.contact-info-card h3 {
  font-size: 1.6rem;
  margin-bottom: 0.8rem;
}

.info-desc {
  color: var(--text-secondary);
  margin-bottom: 2rem;
}

.info-list {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  margin-bottom: 2.5rem;
}

.info-item {
  display: flex;
  align-items: center;
  gap: 1.2rem;
}

.info-icon {
  width: 50px;
  height: 50px;
  border-radius: var(--radius-md);
  background: var(--gradient-glow);
  border: 1px solid var(--border-glow);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  color: var(--accent-cyan);
}

.info-label {
  display: block;
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.info-val {
  font-weight: 600;
  color: var(--text-primary);
}

.resume-download-box {
  background: rgba(255, 255, 255, 0.04);
  border: 1px dashed var(--border-glow);
  padding: 1.4rem;
  border-radius: var(--radius-md);
}

.resume-download-box h4 {
  font-size: 1.05rem;
  margin-bottom: 0.4rem;
  color: var(--accent-purple);
}

.resume-download-box p {
  font-size: 0.88rem;
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

/* Form Styles */
.form-group {
  margin-bottom: 1.5rem;
}

.form-group label {
  display: block;
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--text-secondary);
}

.form-group input, .form-group textarea {
  width: 100%;
  padding: 0.9rem 1.2rem;
  background: rgba(10, 12, 22, 0.5);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-family: var(--font-main);
  font-size: 0.95rem;
  transition: all var(--transition-fast);
}

.form-group input:focus, .form-group textarea:focus {
  outline: none;
  border-color: var(--accent-cyan);
  box-shadow: 0 0 15px rgba(6, 182, 212, 0.25);
}

/* Modal */
.modal {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(10, 12, 22, 0.8);
  backdrop-filter: blur(12px);
  z-index: 2000;
  align-items: center;
  justify-content: center;
  padding: 2rem;
}

.modal.active {
  display: flex;
}

.modal-content {
  max-width: 600px;
  width: 100%;
  padding: 2.5rem;
  position: relative;
  animation: modalFadeIn 0.3s ease-out;
}

@keyframes modalFadeIn {
  from { opacity: 0; transform: scale(0.9); }
  to { opacity: 1; transform: scale(1); }
}

.close-modal {
  position: absolute;
  top: 1.2rem;
  right: 1.5rem;
  background: none;
  border: none;
  font-size: 1.8rem;
  color: var(--text-secondary);
  cursor: pointer;
}

.modal-img {
  width: 100%;
  height: 260px;
  object-fit: cover;
  border-radius: var(--radius-md);
  margin: 1.2rem 0;
}

.modal-desc {
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
}

.modal-tech {
  display: flex;
  gap: 0.6rem;
  flex-wrap: wrap;
}

.modal-tech span {
  background: rgba(139, 92, 246, 0.2);
  color: var(--accent-purple);
  padding: 0.3rem 0.8rem;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  font-weight: 600;
}

/* Toast */
.toast {
  position: fixed;
  bottom: 30px;
  right: 30px;
  background: var(--bg-card);
  border: 1px solid var(--accent-cyan);
  padding: 1rem 1.8rem;
  border-radius: var(--radius-md);
  backdrop-filter: blur(16px);
  box-shadow: var(--shadow-neon);
  display: flex;
  align-items: center;
  gap: 0.8rem;
  color: var(--text-primary);
  transform: translateY(100px);
  opacity: 0;
  transition: all var(--transition-normal);
  z-index: 3000;
}

.toast.show {
  transform: translateY(0);
  opacity: 1;
}

.toast i {
  color: #10b981;
  font-size: 1.3rem;
}

/* Footer */
.footer {
  padding: 2rem 0;
  border-top: 1px solid var(--border-glass);
}

.footer-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  color: var(--text-secondary);
  font-size: 0.9rem;
}

/* Animations */
.fade-in {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}

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

.delay-1 { transition-delay: 0.2s; }
.delay-2 { transition-delay: 0.4s; }
.delay-3 { transition-delay: 0.6s; }
.delay-4 { transition-delay: 0.8s; }

/* Responsive Media Queries */
@media (max-width: 992px) {
  .hero-container {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-title {
    font-size: 2.6rem;
  }

  .hero-cta {
    justify-content: center;
  }

  .hero-stats {
    justify-content: center;
  }

  .grid-2, .grid-3, .skills-wrapper {
    grid-template-columns: 1fr;
  }

  .timeline::before {
    left: 15px;
  }

  .timeline-item {
    padding-left: 45px;
  }

  .timeline-dot {
    left: 8px;
  }
}

@media (max-width: 768px) {
  .mobile-menu-btn {
    display: flex;
  }

  .nav-menu {
    position: fixed;
    top: 70px;
    left: 0;
    width: 100%;
    background: var(--bg-primary);
    flex-direction: column;
    padding: 2rem;
    gap: 1.5rem;
    border-bottom: 1px solid var(--border-glass);
    transform: translateY(-150%);
    transition: transform var(--transition-normal);
  }

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

  .hero-title {
    font-size: 2.1rem;
  }
}