/* ===== VARIABLES ===== */
:root {
  --color-bg: #0a0a0b;
  --color-bg-alt: #111113;
  --color-surface: #1a1a1d;
  --color-surface-hover: #222225;
  --color-border: #2a2a2e;
  --color-text: #e4e4e7;
  --color-text-secondary: #a1a1aa;
  --color-accent: #6366f1;
  --color-accent-hover: #818cf8;
  --color-accent-glow: rgba(99, 102, 241, 0.15);
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
  --nav-height: 64px;
  --container-max: 1100px;
  --radius: 12px;
  --radius-sm: 8px;
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ===== RESET ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; scroll-padding-top: var(--nav-height); }
body {
  font-family: var(--font-sans);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
a { color: inherit; text-decoration: none; }
ul { list-style: none; }
img { max-width: 100%; display: block; }

/* ===== UTILITIES ===== */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 24px;
}
.accent { color: var(--color-accent); }

/* ===== NAVBAR ===== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  z-index: 1000;
  background: rgba(10, 10, 11, 0.8);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition);
}
.navbar.scrolled { border-bottom-color: var(--color-border); }
.nav-container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav-logo {
  font-family: var(--font-mono);
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: -0.5px;
}
.nav-links {
  display: flex;
  gap: 32px;
}
.nav-links a {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  transition: color var(--transition);
  position: relative;
}
.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-accent);
  transition: width var(--transition);
}
.nav-links a:hover,
.nav-links a.active { color: var(--color-text); }
.nav-links a:hover::after,
.nav-links a.active::after { width: 100%; }
.nav-actions { display: flex; align-items: center; gap: 16px; }

/* Lang Toggle */
.lang-toggle {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 20px;
  padding: 4px 12px;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 4px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  transition: border-color var(--transition);
}
.lang-toggle:hover { border-color: var(--color-accent); }
.lang-option { color: var(--color-text-secondary); transition: color var(--transition); }
.lang-option.active { color: var(--color-accent); font-weight: 600; }
.lang-separator { color: var(--color-border); }

/* Hamburger */
.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}
.menu-toggle span {
  width: 22px;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: var(--transition);
}
.menu-toggle.active span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
.menu-toggle.active span:nth-child(2) { opacity: 0; }
.menu-toggle.active span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

/* ===== HERO ===== */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  padding: calc(var(--nav-height) + 40px) 24px 80px;
}
.hero-bg-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(99, 102, 241, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(99, 102, 241, 0.03) 1px, transparent 1px);
  background-size: 60px 60px;
  mask-image: radial-gradient(ellipse at center, black 30%, transparent 70%);
  -webkit-mask-image: radial-gradient(ellipse at center, black 30%, transparent 70%);
}
.hero-content {
  max-width: var(--container-max);
  width: 100%;
  position: relative;
  z-index: 1;
}
.hero-greeting {
  font-family: var(--font-mono);
  font-size: 1rem;
  color: var(--color-accent);
  margin-bottom: 12px;
}
.hero-name {
  font-size: clamp(2.5rem, 7vw, 4.5rem);
  font-weight: 800;
  letter-spacing: -2px;
  line-height: 1.1;
  margin-bottom: 12px;
}
.hero-title {
  font-size: clamp(1.1rem, 2.5vw, 1.5rem);
  font-weight: 400;
  color: var(--color-text-secondary);
  margin-bottom: 24px;
}
.hero-description {
  max-width: 600px;
  color: var(--color-text-secondary);
  font-size: 1.05rem;
  margin-bottom: 36px;
}
.hero-cta { display: flex; gap: 16px; margin-bottom: 48px; }
.hero-social { display: flex; gap: 20px; }
.hero-social a {
  color: var(--color-text-secondary);
  transition: color var(--transition), transform var(--transition);
}
.hero-social a:hover { color: var(--color-accent); transform: translateY(-2px); }

/* Scroll Indicator */
.scroll-indicator {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  animation: bounce 2s infinite;
}
.scroll-arrow {
  width: 24px;
  height: 24px;
  border-right: 2px solid var(--color-text-secondary);
  border-bottom: 2px solid var(--color-text-secondary);
  transform: rotate(45deg);
  opacity: 0.4;
}
@keyframes bounce {
  0%, 20%, 50%, 80%, 100% { transform: translateX(-50%) translateY(0); }
  40% { transform: translateX(-50%) translateY(10px); }
  60% { transform: translateX(-50%) translateY(5px); }
}

/* ===== BUTTONS ===== */
.btn {
  display: inline-flex;
  align-items: center;
  padding: 12px 28px;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 500;
  transition: all var(--transition);
  cursor: pointer;
  border: none;
}
.btn-primary {
  background: var(--color-accent);
  color: white;
}
.btn-primary:hover {
  background: var(--color-accent-hover);
  transform: translateY(-1px);
  box-shadow: 0 8px 30px var(--color-accent-glow);
}
.btn-outline {
  background: transparent;
  color: var(--color-text);
  border: 1px solid var(--color-border);
}
.btn-outline:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  transform: translateY(-1px);
}

/* ===== SECTIONS ===== */
.section {
  padding: 100px 0;
}
.section-alt { background: var(--color-bg-alt); }
.section-title {
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: -1px;
  margin-bottom: 48px;
  position: relative;
  display: inline-block;
}
.section-title::after {
  content: '';
  position: absolute;
  bottom: -8px;
  left: 0;
  width: 48px;
  height: 3px;
  background: var(--color-accent);
  border-radius: 2px;
}

/* ===== ABOUT ===== */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: start;
}
.about-text p {
  color: var(--color-text-secondary);
  margin-bottom: 16px;
  font-size: 1.05rem;
}
.about-stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}
.stat-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 24px;
  text-align: center;
  transition: all var(--transition);
}
.stat-card:hover {
  border-color: var(--color-accent);
  transform: translateY(-2px);
  box-shadow: 0 8px 30px var(--color-accent-glow);
}
.stat-number {
  display: block;
  font-size: 2rem;
  font-weight: 800;
  color: var(--color-accent);
  letter-spacing: -1px;
}
.stat-label {
  font-size: 0.8rem;
  color: var(--color-text-secondary);
  margin-top: 4px;
  display: block;
}

/* ===== SKILLS ===== */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.skill-category {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 28px;
  transition: all var(--transition);
}
.skill-category:hover {
  border-color: var(--color-accent);
  transform: translateY(-3px);
  box-shadow: 0 12px 40px var(--color-accent-glow);
}
.skill-category-icon {
  color: var(--color-accent);
  margin-bottom: 16px;
}
.skill-category h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 16px;
}
.skill-tags { display: flex; flex-wrap: wrap; gap: 8px; }
.skill-tag {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 6px;
  padding: 4px 12px;
  font-size: 0.8rem;
  font-family: var(--font-mono);
  color: var(--color-text-secondary);
  transition: all var(--transition);
}
.skill-category:hover .skill-tag {
  border-color: rgba(99, 102, 241, 0.3);
  color: var(--color-text);
}

/* ===== TIMELINE ===== */
.timeline { position: relative; padding-left: 32px; }
.timeline::before {
  content: '';
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: var(--color-border);
}
.timeline-item {
  position: relative;
  margin-bottom: 48px;
}
.timeline-item:last-child { margin-bottom: 0; }
.timeline-marker {
  position: absolute;
  left: -32px;
  top: 8px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--color-accent);
  border: 3px solid var(--color-bg);
  box-shadow: 0 0 0 2px var(--color-accent);
}
.timeline-content {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 28px;
  transition: all var(--transition);
}
.timeline-content:hover {
  border-color: var(--color-accent);
  box-shadow: 0 8px 30px var(--color-accent-glow);
}
.timeline-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 16px;
  margin-bottom: 4px;
}
.timeline-header h3 {
  font-size: 1.15rem;
  font-weight: 600;
}
.timeline-company {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--color-accent);
}
.timeline-date {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--color-text-secondary);
  white-space: nowrap;
  background: var(--color-bg);
  padding: 4px 12px;
  border-radius: 6px;
  border: 1px solid var(--color-border);
}
.timeline-location {
  font-size: 0.85rem;
  color: var(--color-text-secondary);
  margin-bottom: 16px;
}
.timeline-details {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.timeline-details li {
  position: relative;
  padding-left: 20px;
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
}
.timeline-details li::before {
  content: '>';
  position: absolute;
  left: 0;
  color: var(--color-accent);
  font-family: var(--font-mono);
  font-weight: 700;
}

/* ===== PROJECTS ===== */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.project-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 28px;
  display: flex;
  flex-direction: column;
  transition: all var(--transition);
}
.project-card:hover {
  border-color: var(--color-accent);
  transform: translateY(-4px);
  box-shadow: 0 16px 48px var(--color-accent-glow);
}
.project-card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--color-accent);
  margin-bottom: 16px;
}
.project-card-header a {
  color: var(--color-text-secondary);
  transition: color var(--transition);
}
.project-card-header a:hover { color: var(--color-accent); }
.project-badge {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 600;
  color: #22c55e;
  background: rgba(34, 197, 94, 0.1);
  border: 1px solid rgba(34, 197, 94, 0.3);
  border-radius: 20px;
  padding: 2px 10px;
  margin-bottom: 8px;
  letter-spacing: 0.5px;
}
.project-badge-ai {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 600;
  color: #a78bfa;
  background: rgba(167, 139, 250, 0.1);
  border: 1px solid rgba(167, 139, 250, 0.3);
  border-radius: 20px;
  padding: 2px 10px;
  margin-bottom: 8px;
  margin-left: 6px;
  letter-spacing: 0.5px;
}
.project-card h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 10px;
}
.project-card p {
  color: var(--color-text-secondary);
  font-size: 0.9rem;
  flex: 1;
  margin-bottom: 16px;
}
.project-tags { display: flex; flex-wrap: wrap; gap: 8px; }
.project-tags span {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--color-text-secondary);
}
.project-tags span::before { content: '#'; color: var(--color-accent); }
.projects-cta {
  text-align: center;
  margin-top: 40px;
}

/* ===== EDUCATION ===== */
.education-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin-bottom: 48px;
}
.education-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 28px;
  transition: all var(--transition);
}
.education-card:hover {
  border-color: var(--color-accent);
  transform: translateY(-2px);
  box-shadow: 0 8px 30px var(--color-accent-glow);
}
.education-icon { color: var(--color-accent); margin-bottom: 16px; }
.education-card h3 { font-size: 1.1rem; font-weight: 600; margin-bottom: 4px; }
.education-school {
  font-size: 0.9rem;
  color: var(--color-accent);
  margin-bottom: 4px;
}
.education-date {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--color-text-secondary);
  margin-bottom: 12px;
}
.education-detail {
  font-size: 0.85rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.subsection-title {
  font-size: 1.3rem;
  font-weight: 600;
  margin-bottom: 24px;
}
.certs-grid {
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.cert-item {
  display: flex;
  align-items: center;
  gap: 16px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 16px 20px;
  transition: all var(--transition);
}
.cert-item:hover { border-color: var(--color-accent); }
.cert-badge {
  background: var(--color-accent);
  color: white;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 4px 10px;
  border-radius: 6px;
  white-space: nowrap;
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 48px;
}
.cert-name { font-size: 0.9rem; }

/* ===== CONTACT ===== */
.contact-subtitle {
  color: var(--color-text-secondary);
  font-size: 1.1rem;
  margin-bottom: 36px;
}
.contact-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}
.contact-card {
  display: flex;
  align-items: center;
  gap: 16px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 24px;
  transition: all var(--transition);
  color: var(--color-text);
}
.contact-card:hover {
  border-color: var(--color-accent);
  transform: translateY(-2px);
  box-shadow: 0 8px 30px var(--color-accent-glow);
}
.contact-card svg { color: var(--color-accent); flex-shrink: 0; }
.contact-card span { font-size: 0.9rem; }

/* ===== FOOTER ===== */
.footer {
  border-top: 1px solid var(--color-border);
  padding: 32px 0;
  text-align: center;
}
.footer p {
  font-size: 0.85rem;
  color: var(--color-text-secondary);
}
.footer-year {
  font-family: var(--font-mono);
  margin-top: 4px;
}

/* ===== ANIMATIONS ===== */
.animate-in {
  opacity: 0;
  transform: translateY(20px);
  animation: fadeInUp 0.6s ease forwards;
}
.animate-in:nth-child(1) { animation-delay: 0.1s; }
.animate-in:nth-child(2) { animation-delay: 0.2s; }
.animate-in:nth-child(3) { animation-delay: 0.3s; }
.animate-in:nth-child(4) { animation-delay: 0.4s; }
.animate-in:nth-child(5) { animation-delay: 0.5s; }
.animate-in:nth-child(6) { animation-delay: 0.6s; }
.animate-in:nth-child(7) { animation-delay: 0.7s; }

@keyframes fadeInUp {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== SUBPAGES ===== */
.page-hero {
  padding: calc(var(--nav-height) + 48px) 0 48px;
  background: var(--color-bg);
}
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--color-text-secondary);
  margin-bottom: 16px;
}
.breadcrumb a {
  color: var(--color-accent);
  transition: opacity var(--transition);
}
.breadcrumb a:hover { opacity: 0.8; }
.breadcrumb-sep { color: var(--color-border); }
.page-hero h1 {
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  font-weight: 800;
  letter-spacing: -1px;
  margin-bottom: 8px;
}
.page-hero p {
  color: var(--color-text-secondary);
  font-size: 1.05rem;
  max-width: 600px;
}
.page-badges { display: flex; gap: 8px; margin-bottom: 16px; }

/* Skill Detail Page */
.skill-detail {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 28px;
  margin-bottom: 20px;
  transition: all var(--transition);
}
.skill-detail:hover {
  border-color: var(--color-accent);
  box-shadow: 0 8px 30px var(--color-accent-glow);
}
.skill-detail-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 12px;
}
.skill-detail-header h3 { font-size: 1.1rem; font-weight: 600; }
.skill-level {
  display: flex;
  gap: 4px;
  align-items: center;
}
.skill-level-bar {
  width: 48px;
  height: 6px;
  background: var(--color-border);
  border-radius: 3px;
  overflow: hidden;
}
.skill-level-fill {
  height: 100%;
  background: var(--color-accent);
  border-radius: 3px;
}
.skill-level-label {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--color-text-secondary);
  margin-left: 8px;
}
.skill-detail p {
  color: var(--color-text-secondary);
  font-size: 0.9rem;
  line-height: 1.6;
}
.skill-detail .skill-tags { margin-top: 12px; }

/* Project Detail Page */
.project-detail-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
}
.project-info-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 28px;
}
.project-info-card h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 16px;
  color: var(--color-accent);
}
.project-info-card ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.project-info-card li {
  position: relative;
  padding-left: 20px;
  font-size: 0.9rem;
  color: var(--color-text-secondary);
}
.project-info-card li::before {
  content: '>';
  position: absolute;
  left: 0;
  color: var(--color-accent);
  font-family: var(--font-mono);
  font-weight: 700;
}
.project-tech-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 8px;
}
.tech-badge {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 8px 16px;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--color-text);
  transition: all var(--transition);
}
.tech-badge:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}
.project-links {
  display: flex;
  gap: 12px;
  margin-top: 24px;
}
.back-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.9rem;
  color: var(--color-accent);
  margin-top: 32px;
  transition: all var(--transition);
}
.back-link:hover { opacity: 0.8; transform: translateX(-4px); }

/* ===== RESPONSIVE ===== */
@media (max-width: 900px) {
  .nav-links { display: none; }
  .nav-links.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: rgba(10, 10, 11, 0.95);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    padding: 24px;
    gap: 20px;
    border-bottom: 1px solid var(--color-border);
  }
  .menu-toggle { display: flex; }

  .about-grid { grid-template-columns: 1fr; }
  .skills-grid { grid-template-columns: repeat(2, 1fr); }
  .projects-grid { grid-template-columns: repeat(2, 1fr); }
  .education-grid { grid-template-columns: 1fr; }
  .timeline-header { flex-direction: column; }
  .project-detail-grid { grid-template-columns: 1fr; }
}

@media (max-width: 600px) {
  .section { padding: 64px 0; }
  .skills-grid { grid-template-columns: 1fr; }
  .projects-grid { grid-template-columns: 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
  .about-stats { grid-template-columns: 1fr 1fr; }
  .hero-cta { flex-direction: column; align-items: flex-start; }
  .hero-name { letter-spacing: -1px; }
  .section-title { font-size: 1.5rem; }
}