*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --bg-primary: #0a0a0f;
  --bg-secondary: #12121a;
  --bg-card: #1a1a2e;
  --bg-card-hover: #22223a;
  --text-primary: #e8e8f0;
  --text-secondary: #9999b0;
  --text-muted: #666680;
  --accent: #6c63ff;
  --accent-light: #8b83ff;
  --accent-glow: rgba(108, 99, 255, 0.15);
  --accent-secondary: #00d4aa;
  --border: #2a2a3e;
  --star-color: #fbbf24;
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
  --max-width: 1100px;
  --radius: 12px;
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
  font-family: var(--font-sans);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

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

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

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

/* ─── Navigation ──────────────────────────────────── */

.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(10, 10, 15, 0.85);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
  transition: box-shadow var(--transition);
}

.nav.scrolled {
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.3);
}

.nav-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.nav-logo {
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--text-primary);
  letter-spacing: -0.5px;
}

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

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

.nav-links a {
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-weight: 500;
  position: relative;
  padding: 0.25rem 0;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent);
  border-radius: 1px;
  transition: width var(--transition);
}

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

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

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: var(--transition);
}

/* ─── Hero ────────────────────────────────────────── */

.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 6rem 2rem 4rem;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle at 30% 40%, var(--accent-glow) 0%, transparent 50%),
              radial-gradient(circle at 70% 60%, rgba(0, 212, 170, 0.08) 0%, transparent 50%);
  animation: float 20s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translate(0, 0) rotate(0deg); }
  33% { transform: translate(30px, -30px) rotate(1deg); }
  66% { transform: translate(-20px, 20px) rotate(-1deg); }
}

.hero-content {
  text-align: center;
  max-width: 720px;
  position: relative;
  z-index: 1;
}

.hero-greeting {
  font-family: var(--font-mono);
  font-size: 0.95rem;
  color: var(--accent);
  margin-bottom: 1rem;
  letter-spacing: 1px;
}

.hero-name {
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -1.5px;
  margin-bottom: 1.25rem;
  background: linear-gradient(135deg, var(--text-primary) 0%, var(--accent-light) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-title {
  font-size: clamp(1.1rem, 2.5vw, 1.4rem);
  color: var(--text-secondary);
  font-weight: 400;
  margin-bottom: 2rem;
  line-height: 1.6;
}

.hero-stats {
  display: flex;
  justify-content: center;
  gap: 3rem;
  margin-bottom: 2.5rem;
  flex-wrap: wrap;
}

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

.hero-stat-value {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--accent);
  display: block;
}

.hero-stat-label {
  font-size: 0.8rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-top: 0.25rem;
}

.hero-actions {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.75rem;
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
  border: none;
  font-family: var(--font-sans);
}

.btn-primary {
  background: var(--accent);
  color: #fff;
}

.btn-primary:hover {
  background: var(--accent-light);
  color: #fff;
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(108, 99, 255, 0.3);
}

.btn-outline {
  background: transparent;
  color: var(--text-primary);
  border: 1.5px solid var(--border);
}

.btn-outline:hover {
  border-color: var(--accent);
  color: var(--accent-light);
  transform: translateY(-2px);
}

/* ─── Page Sections ───────────────────────────────── */

.section {
  padding: 5rem 2rem;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
}

.section-header {
  margin-bottom: 3.5rem;
}

.section-title {
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: -0.5px;
  margin-bottom: 0.75rem;
}

.section-title span {
  color: var(--accent);
}

.section-subtitle {
  color: var(--text-secondary);
  font-size: 1.05rem;
}

/* ─── Page Header (for sub-pages) ─────────────────── */

.page-header {
  padding: 8rem 2rem 3rem;
  text-align: center;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
}

.page-header .section-title {
  font-size: 2.5rem;
}

/* ─── About ───────────────────────────────────────── */

.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: start;
}

.about-text p {
  color: var(--text-secondary);
  margin-bottom: 1.25rem;
  font-size: 1.05rem;
}

.about-highlights {
  display: grid;
  gap: 1rem;
  margin-top: 2rem;
}

.highlight-card {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1rem 1.25rem;
  background: var(--bg-card);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  transition: all var(--transition);
}

.highlight-card:hover {
  border-color: var(--accent);
  background: var(--bg-card-hover);
}

.highlight-icon {
  width: 42px;
  height: 42px;
  border-radius: 10px;
  background: var(--accent-glow);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  flex-shrink: 0;
}

.highlight-text {
  font-size: 0.95rem;
  font-weight: 500;
}

.highlight-sub {
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-top: 0.15rem;
}

.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 1.5rem;
}

.skill-category h3 {
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--text-muted);
  margin-bottom: 0.75rem;
}

.skill-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.skill-tag {
  padding: 0.35rem 0.85rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 0.85rem;
  color: var(--text-secondary);
  transition: all var(--transition);
}

.skill-tag:hover {
  border-color: var(--accent);
  color: var(--accent-light);
}

/* ─── Experience Timeline ─────────────────────────── */

.timeline {
  position: relative;
  padding-left: 2.5rem;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(to bottom, var(--accent), var(--accent-secondary), var(--border));
  border-radius: 1px;
}

.timeline-item {
  position: relative;
  padding-bottom: 3rem;
}

.timeline-item:last-child {
  padding-bottom: 0;
}

.timeline-dot {
  position: absolute;
  left: -2.5rem;
  top: 0.35rem;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--accent);
  border: 3px solid var(--bg-primary);
  box-shadow: 0 0 0 3px var(--accent-glow);
  transform: translateX(-5px);
}

.timeline-year {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--accent);
  letter-spacing: 1px;
  margin-bottom: 0.35rem;
}

.timeline-role {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 0.25rem;
}

.timeline-company {
  color: var(--accent-secondary);
  font-weight: 500;
  font-size: 0.95rem;
  margin-bottom: 0.5rem;
}

.timeline-desc {
  color: var(--text-secondary);
  font-size: 0.95rem;
  max-width: 550px;
}

/* ─── Projects Grid ───────────────────────────────── */

.projects-filter {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin-bottom: 2rem;
}

.filter-btn {
  padding: 0.4rem 1rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text-secondary);
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition);
  font-family: var(--font-sans);
}

.filter-btn:hover,
.filter-btn.active {
  border-color: var(--accent);
  color: var(--accent-light);
  background: var(--accent-glow);
}

.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 1.5rem;
}

.project-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.75rem;
  transition: all var(--transition);
  display: flex;
  flex-direction: column;
  position: relative;
  overflow: hidden;
}

.project-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--accent), var(--accent-secondary));
  opacity: 0;
  transition: opacity var(--transition);
}

.project-card:hover {
  border-color: var(--accent);
  background: var(--bg-card-hover);
  transform: translateY(-4px);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.3);
}

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

.project-card-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  margin-bottom: 1rem;
}

.project-icon {
  font-size: 1.5rem;
}

.project-stars {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.85rem;
  color: var(--star-color);
  font-weight: 600;
}

.project-stars svg {
  width: 16px;
  height: 16px;
  fill: var(--star-color);
}

.project-name {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.project-name a {
  color: var(--text-primary);
}

.project-name a:hover {
  color: var(--accent-light);
}

.project-desc {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.6;
  flex-grow: 1;
  margin-bottom: 1.25rem;
}

.project-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.project-lang {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.82rem;
  color: var(--text-muted);
}

.lang-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
}

.lang-java { background: #b07219; }
.lang-kotlin { background: #A97BFF; }
.lang-typescript { background: #3178c6; }
.lang-javascript { background: #f1e05a; }
.lang-go { background: #00ADD8; }
.lang-python { background: #3572A5; }
.lang-jupyter { background: #DA5B0B; }
.lang-nestjs { background: #e0234e; }

.project-link {
  font-size: 0.85rem;
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

/* ─── Contact ─────────────────────────────────────── */

.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
}

.contact-info p {
  color: var(--text-secondary);
  font-size: 1.05rem;
  margin-bottom: 2rem;
}

.contact-links {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.contact-link {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1rem 1.25rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text-primary);
  transition: all var(--transition);
}

.contact-link:hover {
  border-color: var(--accent);
  background: var(--bg-card-hover);
  transform: translateX(4px);
  color: var(--text-primary);
}

.contact-link-icon {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  background: var(--accent-glow);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.contact-link-icon svg {
  width: 20px;
  height: 20px;
  fill: var(--accent-light);
}

.contact-link-text {
  font-weight: 500;
  font-size: 0.95rem;
}

.contact-link-sub {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.contact-form {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.form-group label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.form-group input,
.form-group textarea {
  padding: 0.75rem 1rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text-primary);
  font-size: 0.95rem;
  font-family: var(--font-sans);
  transition: border-color var(--transition);
  outline: none;
}

.form-group input:focus,
.form-group textarea:focus {
  border-color: var(--accent);
}

.form-group textarea {
  min-height: 120px;
  resize: vertical;
}

/* ─── Footer ──────────────────────────────────────── */

.footer {
  padding: 2.5rem 2rem;
  border-top: 1px solid var(--border);
  text-align: center;
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
}

.footer-text {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.footer-socials {
  display: flex;
  gap: 1rem;
}

.footer-socials a {
  width: 36px;
  height: 36px;
  border-radius: 8px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition);
}

.footer-socials a:hover {
  border-color: var(--accent);
  background: var(--accent-glow);
  transform: translateY(-2px);
}

.footer-socials svg {
  width: 16px;
  height: 16px;
  fill: var(--text-secondary);
}

.footer-socials a:hover svg {
  fill: var(--accent-light);
}

/* ─── Animations ──────────────────────────────────── */

.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

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

/* ─── Responsive ──────────────────────────────────── */

@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: rgba(10, 10, 15, 0.98);
    flex-direction: column;
    padding: 1.5rem 2rem;
    gap: 1rem;
    border-bottom: 1px solid var(--border);
  }

  .nav-links.open {
    display: flex;
  }

  .nav-toggle {
    display: flex;
  }

  .about-grid,
  .contact-grid {
    grid-template-columns: 1fr;
    gap: 2.5rem;
  }

  .hero-stats {
    gap: 2rem;
  }

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

  .section {
    padding: 3.5rem 1.25rem;
  }

  .page-header {
    padding: 6rem 1.25rem 2.5rem;
  }

  .footer-inner {
    flex-direction: column;
  }
}

@media (max-width: 480px) {
  .hero-name {
    font-size: 2rem;
  }

  .hero-stats {
    flex-direction: column;
    gap: 1rem;
  }

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

  .btn {
    width: 100%;
    justify-content: center;
  }
}