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

:root {
  --bg: #090b10;
  --bg-2: #0d1117;
  --bg-card: #111520;
  --bg-card-hover: #161b28;
  --border: rgba(255,255,255,0.07);
  --border-hover: rgba(99,179,237,0.3);
  --text: #e2e8f0;
  --text-muted: #7d8fa8;
  --text-faint: #4a5568;
  --accent: #63b3ed;
  --accent-2: #9f7aea;
  --accent-green: #48bb78;
  --accent-orange: #ed8936;
  --glow: rgba(99,179,237,0.15);
  --radius: 12px;
  --radius-lg: 20px;
  --font: 'Inter', sans-serif;
  --font-mono: 'Fira Code', monospace;
}

html { scroll-behavior: smooth; }

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

a { color: inherit; text-decoration: none; }
strong { color: #fff; font-weight: 600; }
ul { list-style: none; }

/* Scrollbar */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: #2d3748; border-radius: 3px; }

/* ============================================
   UTILITIES
   ============================================ */
.container { max-width: 1100px; margin: 0 auto; padding: 0 24px; }

.gradient-text {
  background: linear-gradient(135deg, var(--accent) 0%, var(--accent-2) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

section { padding: 96px 0; }

.section-header { margin-bottom: 56px; }
.section-header.centered { text-align: center; }
.section-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--accent);
  letter-spacing: 0.1em;
  margin-bottom: 12px;
}
.section-header h2 {
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  font-weight: 800;
  color: #fff;
  letter-spacing: -0.02em;
}
.section-sub { color: var(--text-muted); margin-top: 10px; font-size: 0.95rem; }
.section-sub a { color: var(--accent); transition: opacity .2s; }
.section-sub a:hover { opacity: .7; }

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: 50px;
  font-size: 0.9rem;
  font-weight: 600;
  transition: all 0.25s ease;
  cursor: pointer;
  border: none;
}
.btn-primary {
  background: linear-gradient(135deg, var(--accent) 0%, var(--accent-2) 100%);
  color: #000;
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 8px 30px rgba(99,179,237,0.4); }
.btn-ghost {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
}
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); transform: translateY(-2px); }

/* ============================================
   NAVBAR
   ============================================ */
#navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  padding: 16px 0;
  transition: all 0.3s ease;
}
#navbar.scrolled {
  background: rgba(9,11,16,0.92);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
  padding: 12px 0;
}
.nav-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav-logo {
  font-size: 1.4rem;
  font-weight: 800;
  color: #fff;
  letter-spacing: -0.03em;
}
.dot { color: var(--accent); }
.nav-links {
  display: flex;
  align-items: center;
  gap: 8px;
}
.nav-links a {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-muted);
  padding: 6px 14px;
  border-radius: 6px;
  transition: all .2s;
}
.nav-links a:hover, .nav-links a.active { color: #fff; }
.nav-cta {
  background: linear-gradient(135deg, var(--accent), var(--accent-2)) !important;
  color: #000 !important;
  font-weight: 600 !important;
}
.mobile-menu-btn {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}
.mobile-menu-btn span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: all .3s;
}
.mobile-menu {
  display: none;
  flex-direction: column;
  padding: 12px 24px;
  gap: 4px;
  background: rgba(9,11,16,0.98);
  border-top: 1px solid var(--border);
}
.mobile-menu a {
  padding: 10px 0;
  color: var(--text-muted);
  font-weight: 500;
  border-bottom: 1px solid var(--border);
  transition: color .2s;
}
.mobile-menu a:hover { color: #fff; }
.mobile-menu.open { display: flex; }

/* ============================================
   HERO
   ============================================ */
#hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
  padding: 120px 0 80px;
}
.hero-bg {
  position: absolute;
  inset: 0;
  pointer-events: none;
}
.grid-overlay {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,0.02) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.02) 1px, transparent 1px);
  background-size: 60px 60px;
}
.glow {
  position: absolute;
  border-radius: 50%;
  filter: blur(120px);
  pointer-events: none;
}
.glow-1 {
  width: 600px; height: 600px;
  background: rgba(99,179,237,0.08);
  top: -200px; left: -100px;
}
.glow-2 {
  width: 400px; height: 400px;
  background: rgba(159,122,234,0.08);
  bottom: 0; right: -100px;
}
.hero-content {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
  position: relative;
  z-index: 1;
}
.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(72,187,120,0.1);
  border: 1px solid rgba(72,187,120,0.25);
  color: var(--accent-green);
  font-size: 0.78rem;
  font-weight: 600;
  padding: 6px 16px;
  border-radius: 50px;
  margin-bottom: 28px;
  letter-spacing: 0.04em;
}
.badge-dot {
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--accent-green);
  animation: pulse 2s infinite;
}
@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: .5; transform: scale(1.4); }
}
.hero-name {
  font-size: clamp(3rem, 8vw, 6.5rem);
  font-weight: 800;
  line-height: 1.0;
  letter-spacing: -0.04em;
  color: #fff;
  margin-bottom: 16px;
}
.hero-title {
  font-size: clamp(1rem, 2.5vw, 1.4rem);
  font-weight: 600;
  color: var(--text-muted);
  margin-bottom: 4px;
}
.hero-subtitle {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--accent);
  margin-bottom: 28px;
  opacity: .8;
}
.hero-summary {
  max-width: 580px;
  color: var(--text-muted);
  font-size: 1.05rem;
  line-height: 1.75;
  margin-bottom: 36px;
}
.hero-summary strong { color: var(--text); }
.hero-cta {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 56px;
}
.hero-stats {
  display: flex;
  align-items: center;
  gap: 32px;
  flex-wrap: wrap;
}
.stat {
  display: flex;
  flex-direction: column;
}
.stat-num {
  font-size: 2rem;
  font-weight: 800;
  color: #fff;
  letter-spacing: -0.03em;
  line-height: 1;
}
.stat-label {
  font-size: 0.72rem;
  color: var(--text-faint);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-top: 4px;
}
.stat-divider {
  width: 1px;
  height: 40px;
  background: var(--border);
}
.scroll-indicator {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  color: var(--text-faint);
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  animation: fadeInUp 1s 1s backwards;
}
.scroll-line {
  width: 1px;
  height: 40px;
  background: linear-gradient(to bottom, var(--text-faint), transparent);
  animation: scrollAnim 2s infinite;
}
@keyframes scrollAnim {
  0% { opacity: 1; transform: scaleY(1) translateY(0); }
  100% { opacity: 0; transform: scaleY(0.5) translateY(20px); }
}
@keyframes fadeInUp {
  from { opacity: 0; transform: translate(-50%, 20px); }
  to { opacity: 1; transform: translate(-50%, 0); }
}

/* ============================================
   ABOUT
   ============================================ */
#about { background: var(--bg-2); }
.about-grid {
  display: grid;
  grid-template-columns: 1fr 380px;
  gap: 48px;
  align-items: start;
}
.about-text p {
  color: var(--text-muted);
  margin-bottom: 18px;
  font-size: 1rem;
  line-height: 1.8;
}
.about-text p strong { color: var(--text); }
.about-links {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 28px;
}
.social-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 18px;
  border-radius: 8px;
  border: 1px solid var(--border);
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-muted);
  transition: all .2s;
}
.social-link svg { width: 16px; height: 16px; }
.social-link:hover {
  border-color: var(--accent);
  color: var(--accent);
  transform: translateY(-2px);
}
.about-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px;
  position: sticky;
  top: 80px;
}
.info-block { margin-bottom: 24px; }
.info-item {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding: 12px 0;
  border-bottom: 1px solid var(--border);
}
.info-item:last-child { border-bottom: none; }
.info-label {
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-faint);
}
.info-val {
  font-size: 0.9rem;
  color: var(--text);
}
.info-val a { color: var(--accent); }
.info-val a:hover { text-decoration: underline; }
.cert-badges { display: flex; flex-direction: column; gap: 10px; }
.cert-badge {
  display: flex;
  align-items: center;
  gap: 14px;
  background: rgba(99,179,237,0.06);
  border: 1px solid rgba(99,179,237,0.15);
  border-radius: 10px;
  padding: 14px 16px;
}
.cert-icon { font-size: 1.5rem; }
.cert-name { font-size: 0.85rem; font-weight: 600; color: var(--text); }
.cert-sub { font-size: 0.72rem; color: var(--text-muted); margin-top: 2px; }

/* ============================================
   EXPERIENCE
   ============================================ */
#experience { background: var(--bg); }
.timeline { position: relative; padding-left: 32px; }
.timeline::before {
  content: '';
  position: absolute;
  left: 0; top: 8px; bottom: 0;
  width: 2px;
  background: linear-gradient(to bottom, var(--accent), var(--accent-2), transparent);
}
.timeline-item {
  position: relative;
  margin-bottom: 48px;
  opacity: 0;
  transform: translateX(-20px);
  animation: slideIn .6s forwards;
}
.timeline-item:nth-child(1) { animation-delay: .1s; }
.timeline-item:nth-child(2) { animation-delay: .2s; }
.timeline-item:nth-child(3) { animation-delay: .3s; }
@keyframes slideIn {
  to { opacity: 1; transform: translateX(0); }
}
.timeline-marker {
  position: absolute;
  left: -37px;
  top: 20px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid var(--bg);
  box-shadow: 0 0 12px rgba(99,179,237,0.5);
}
.timeline-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 32px;
  transition: border-color .3s, transform .3s;
}
.timeline-card:hover {
  border-color: rgba(99,179,237,0.2);
  transform: translateX(4px);
}
.job-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 16px;
  margin-bottom: 16px;
  flex-wrap: wrap;
}
.job-title { font-size: 1.2rem; font-weight: 700; color: #fff; margin-bottom: 4px; }
.job-company { font-size: 0.95rem; color: var(--accent); font-weight: 500; }
.job-meta { font-size: 0.8rem; color: var(--text-faint); margin-top: 4px; }
.active-badge {
  background: linear-gradient(135deg, var(--accent-green), #38a169);
  color: #000;
  font-size: 0.7rem;
  font-weight: 700;
  padding: 4px 12px;
  border-radius: 50px;
  white-space: nowrap;
}
.job-project {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text-faint);
  margin-bottom: 14px;
  padding: 8px 14px;
  background: rgba(255,255,255,0.03);
  border-radius: 6px;
  border-left: 2px solid var(--accent);
}
.job-stack {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 24px;
}
.job-stack span {
  font-size: 0.7rem;
  padding: 3px 10px;
  border-radius: 4px;
  background: rgba(99,179,237,0.08);
  border: 1px solid rgba(99,179,237,0.15);
  color: var(--accent);
  font-weight: 500;
  font-family: var(--font-mono);
}
.achievements { display: flex; flex-direction: column; gap: 20px; }
.achievement-group {}
.ach-label {
  display: inline-block;
  font-size: 0.65rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  padding: 3px 10px;
  border-radius: 4px;
  margin-bottom: 10px;
}
.ach-label.ai { background: rgba(159,122,234,0.15); color: var(--accent-2); border: 1px solid rgba(159,122,234,0.2); }
.ach-label.arch { background: rgba(99,179,237,0.1); color: var(--accent); border: 1px solid rgba(99,179,237,0.2); }
.ach-label.perf { background: rgba(72,187,120,0.1); color: var(--accent-green); border: 1px solid rgba(72,187,120,0.2); }
.ach-label.lead { background: rgba(237,137,54,0.1); color: var(--accent-orange); border: 1px solid rgba(237,137,54,0.2); }
.achievement-group ul { display: flex; flex-direction: column; gap: 8px; }
.achievement-group li {
  font-size: 0.88rem;
  color: var(--text-muted);
  padding-left: 16px;
  position: relative;
  line-height: 1.6;
}
.achievement-group li::before {
  content: '▸';
  position: absolute;
  left: 0;
  color: var(--text-faint);
  font-size: 0.7rem;
  top: 2px;
}
.achievement-group li strong { color: var(--text); }
.simple-achievements {
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.simple-achievements li {
  font-size: 0.88rem;
  color: var(--text-muted);
  padding-left: 20px;
  position: relative;
  line-height: 1.6;
}
.simple-achievements li::before {
  content: '▸';
  position: absolute;
  left: 0;
  color: var(--text-faint);
  font-size: 0.7rem;
  top: 2px;
}
.simple-achievements li strong { color: var(--text); }

/* ============================================
   SKILLS
   ============================================ */
#skills { background: var(--bg-2); }
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 16px;
}
.skill-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  transition: all .3s;
}
.skill-card:hover {
  border-color: rgba(99,179,237,0.25);
  transform: translateY(-4px);
  box-shadow: 0 12px 40px rgba(0,0,0,0.3);
}
.skill-icon { font-size: 1.8rem; margin-bottom: 12px; }
.skill-card h3 { font-size: 0.95rem; font-weight: 700; color: #fff; margin-bottom: 14px; }
.skill-tags { display: flex; flex-wrap: wrap; gap: 6px; }
.skill-tags span {
  font-size: 0.72rem;
  padding: 4px 10px;
  border-radius: 4px;
  background: rgba(255,255,255,0.04);
  color: var(--text-muted);
  border: 1px solid var(--border);
  transition: all .2s;
}
.skill-card:hover .skill-tags span {
  border-color: rgba(99,179,237,0.15);
  color: var(--text);
}

/* ============================================
   OPEN SOURCE
   ============================================ */
#oss { background: var(--bg); }
.oss-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 16px;
}
.oss-card {
  display: flex;
  flex-direction: column;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  transition: all .3s;
}
.oss-card:hover {
  border-color: rgba(99,179,237,0.3);
  transform: translateY(-4px);
  box-shadow: 0 12px 40px rgba(0,0,0,0.3);
}
.oss-card-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 14px;
}
.oss-icon { font-size: 1.8rem; }
.oss-arrow {
  font-size: 1.2rem;
  color: var(--text-faint);
  transition: color .2s, transform .2s;
}
.oss-card:hover .oss-arrow { color: var(--accent); transform: translate(2px, -2px); }
.oss-card h3 { font-size: 1rem; font-weight: 700; color: #fff; margin-bottom: 8px; }
.oss-card p { font-size: 0.85rem; color: var(--text-muted); line-height: 1.6; flex: 1; }
.oss-lang {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 16px;
  font-size: 0.75rem;
  color: var(--text-faint);
  font-family: var(--font-mono);
}
.lang-dot {
  width: 10px; height: 10px;
  border-radius: 50%;
  flex-shrink: 0;
}
.lang-dot.python { background: #3572A5; }
.lang-dot.ts { background: #3178c6; }
.lang-dot.js { background: #f7df1e; }

/* ============================================
   WRITING
   ============================================ */
#writing { background: var(--bg-2); }
.articles-list { display: flex; flex-direction: column; gap: 16px; }
.article-card {
  display: flex;
  flex-direction: column;
  gap: 8px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px 28px;
  transition: all .3s;
}
.article-card:hover {
  border-color: rgba(99,179,237,0.25);
  transform: translateX(6px);
}
.article-meta {
  display: flex;
  align-items: center;
  gap: 12px;
}
.article-tag {
  font-size: 0.67rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  padding: 3px 10px;
  border-radius: 4px;
  background: rgba(99,179,237,0.1);
  color: var(--accent);
  border: 1px solid rgba(99,179,237,0.2);
}
.article-date { font-size: 0.8rem; color: var(--text-faint); font-family: var(--font-mono); }
.article-card h3 { font-size: 1rem; font-weight: 600; color: #fff; line-height: 1.4; }
.article-card p { font-size: 0.85rem; color: var(--text-muted); }
.read-more { font-size: 0.8rem; color: var(--text-faint); margin-top: 4px; transition: color .2s; }
.article-card:hover .read-more { color: var(--accent); }

/* ============================================
   CONTACT
   ============================================ */
#contact {
  background: var(--bg);
  position: relative;
  overflow: hidden;
}
.contact-inner { position: relative; }
.contact-glow {
  position: absolute;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(99,179,237,0.05), transparent 70%);
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  pointer-events: none;
}
.contact-desc {
  color: var(--text-muted);
  max-width: 500px;
  margin: 16px auto 0;
  font-size: 1rem;
  line-height: 1.7;
}
.contact-cards {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 16px;
  margin-top: 48px;
}
.contact-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px 32px;
  min-width: 200px;
  transition: all .3s;
  text-align: center;
}
.contact-card:hover {
  border-color: rgba(99,179,237,0.35);
  transform: translateY(-6px);
  box-shadow: 0 20px 50px rgba(0,0,0,0.4), 0 0 0 1px rgba(99,179,237,0.1);
}
.contact-icon { font-size: 2rem; }
.contact-label { font-size: 0.72rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.1em; color: var(--text-faint); }
.contact-val { font-size: 0.85rem; color: var(--text-muted); font-family: var(--font-mono); }

/* ============================================
   FOOTER
   ============================================ */
footer {
  padding: 32px 0;
  border-top: 1px solid var(--border);
  background: var(--bg);
}
.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}
.footer-logo { font-size: 1.2rem; font-weight: 800; color: #fff; }
.footer-text { font-size: 0.8rem; color: var(--text-faint); }
.footer-links { display: flex; gap: 20px; }
.footer-links a { font-size: 0.8rem; color: var(--text-faint); transition: color .2s; }
.footer-links a:hover { color: var(--accent); }

/* ============================================
   REVEAL ANIMATIONS
   ============================================ */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity .7s ease, transform .7s ease;
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ============================================
   RESPONSIVE
   ============================================ */
@media (max-width: 768px) {
  section { padding: 64px 0; }
  .nav-links { display: none; }
  .mobile-menu-btn { display: flex; }
  .about-grid { grid-template-columns: 1fr; }
  .about-card { position: static; }
  .hero-stats { gap: 20px; }
  .stat-divider { height: 30px; }
  .skills-grid { grid-template-columns: 1fr 1fr; }
  .oss-grid { grid-template-columns: 1fr; }
  .footer-inner { flex-direction: column; text-align: center; }
  .contact-cards { flex-direction: column; align-items: center; }
}
@media (max-width: 480px) {
  .skills-grid { grid-template-columns: 1fr; }
  .hero-stats { flex-direction: column; gap: 12px; }
  .stat-divider { display: none; }
}