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

:root {
  --bg:         #0a0a0f;
  --bg-card:    #111118;
  --bg-card2:   #16161f;
  --border:     rgba(255,255,255,0.07);
  --border-h:   rgba(255,255,255,0.15);
  --accent:     #7c6fef;
  --accent2:    #5eead4;
  --accent3:    #f472b6;
  --text:       #e2e8f0;
  --text-muted: #94a3b8;
  --text-dim:   #64748b;
  --gradient:   linear-gradient(135deg, #7c6fef, #5eead4);
  --shadow:     0 4px 24px rgba(0,0,0,0.4);
  --radius:     14px;
  --radius-sm:  8px;
  --font:       'Inter', sans-serif;
  --mono:       'JetBrains Mono', 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; }
ul { list-style: none; }

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* ========================================
   NAV
======================================== */
#navbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: rgba(10,10,15,0.8);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
  transition: box-shadow 0.3s;
}
#navbar.scrolled { box-shadow: 0 4px 32px rgba(0,0,0,0.5); }

.nav-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 1.5rem;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-family: var(--mono);
  font-weight: 700;
  font-size: 1.1rem;
  background: var(--gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: 2px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}
.nav-links a {
  padding: 0.4rem 0.8rem;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-muted);
  transition: color 0.2s, background 0.2s;
}
.nav-links a:hover { color: var(--text); background: var(--border); }
.nav-links a.active { color: var(--accent); }

.nav-scholar {
  border: 1px solid var(--border);
  color: var(--accent2) !important;
  transition: border-color 0.2s, background 0.2s !important;
}
.nav-scholar:hover { border-color: var(--accent2) !important; background: rgba(94,234,212,0.08) !important; }

.hamburger { display: none; flex-direction: column; gap: 5px; background: none; border: none; cursor: pointer; padding: 4px; }
.hamburger span { display: block; width: 22px; height: 2px; background: var(--text-muted); border-radius: 2px; transition: 0.3s; }

/* ========================================
   HERO
======================================== */
#hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  position: relative;
  padding: 6rem 1.5rem 4rem;
  text-align: center;
  overflow: hidden;
}

.hero-bg {
  position: absolute; inset: 0; z-index: 0;
}

.blob {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.18;
  animation: blobFloat 8s ease-in-out infinite alternate;
}
.blob-1 { width: 500px; height: 500px; background: #7c6fef; top: -100px; left: -100px; animation-delay: 0s; }
.blob-2 { width: 400px; height: 400px; background: #5eead4; bottom: 0; right: -80px; animation-delay: 3s; }
.blob-3 { width: 300px; height: 300px; background: #f472b6; top: 40%; left: 50%; transform: translate(-50%,-50%); animation-delay: 6s; }

@keyframes blobFloat {
  from { transform: translateY(0) scale(1); }
  to   { transform: translateY(-40px) scale(1.08); }
}

.blob-3 { animation: blobFloat3 8s ease-in-out infinite alternate; }
@keyframes blobFloat3 {
  from { transform: translate(-50%,-50%) scale(1); }
  to   { transform: translate(-50%,-50%) scale(1.15) rotate(20deg); }
}

.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;
}

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

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: rgba(94,234,212,0.1);
  border: 1px solid rgba(94,234,212,0.25);
  color: var(--accent2);
  padding: 0.35rem 1rem;
  border-radius: 99px;
  font-size: 0.8rem;
  font-weight: 500;
  margin-bottom: 1.5rem;
  animation: fadeDown 0.6s ease both;
}

.badge-dot {
  width: 7px; height: 7px;
  background: var(--accent2);
  border-radius: 50%;
  animation: pulse 2s infinite;
}
@keyframes pulse {
  0%,100% { opacity: 1; transform: scale(1); }
  50%      { opacity: 0.5; transform: scale(1.4); }
}

.hero-name {
  font-size: clamp(2.8rem, 7vw, 5rem);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -2px;
  margin-bottom: 0.75rem;
  animation: fadeDown 0.6s 0.1s ease both;
}

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

.hero-tagline {
  font-size: 1.1rem;
  font-weight: 500;
  color: var(--text-muted);
  letter-spacing: 0.05em;
  text-transform: uppercase;
  margin-bottom: 1.25rem;
  animation: fadeDown 0.6s 0.2s ease both;
}

.hero-summary {
  font-size: 1rem;
  color: var(--text-muted);
  max-width: 560px;
  margin: 0 auto 2rem;
  animation: fadeDown 0.6s 0.3s ease both;
}
.hero-summary strong { color: var(--text); }

.hero-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  justify-content: center;
  margin-bottom: 1.5rem;
  animation: fadeDown 0.6s 0.4s ease both;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.6rem 1.3rem;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s, opacity 0.2s;
  border: none;
}
.btn:hover { transform: translateY(-2px); }

.btn-primary {
  background: var(--gradient);
  color: #fff;
  box-shadow: 0 4px 20px rgba(124,111,239,0.4);
}
.btn-primary:hover { box-shadow: 0 6px 28px rgba(124,111,239,0.6); }

.btn-ghost {
  background: var(--bg-card);
  color: var(--text);
  border: 1px solid var(--border);
}
.btn-ghost:hover { border-color: var(--border-h); background: var(--bg-card2); }

.hero-meta {
  display: flex;
  gap: 1.5rem;
  justify-content: center;
  font-size: 0.82rem;
  color: var(--text-dim);
  animation: fadeDown 0.6s 0.5s ease both;
}
.hero-meta i { margin-right: 0.35rem; }

.hero-scroll {
  position: absolute; bottom: 2rem; left: 50%; transform: translateX(-50%);
  z-index: 1;
}
.scroll-indicator {
  width: 36px; height: 36px;
  border: 1px solid var(--border);
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  color: var(--text-dim);
  font-size: 0.75rem;
  animation: bounce 2s infinite;
}
@keyframes bounce {
  0%,100% { transform: translateY(0); }
  50%      { transform: translateY(8px); }
}

@keyframes fadeDown {
  from { opacity: 0; transform: translateY(-16px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ========================================
   STATS
======================================== */
#stats {
  padding: 3rem 0;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  background: var(--bg-card);
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
  text-align: center;
}

.stat-card {
  padding: 1.5rem 1rem;
}

.stat-number {
  font-size: 2.8rem;
  font-weight: 800;
  background: var(--gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
  margin-bottom: 0.4rem;
  font-family: var(--mono);
}

.stat-label {
  font-size: 0.82rem;
  color: var(--text-muted);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* ========================================
   SECTION COMMON
======================================== */
section { padding: 6rem 0; }

.section-header {
  margin-bottom: 3rem;
}

.section-tag {
  display: inline-block;
  font-family: var(--mono);
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--accent);
  background: rgba(124,111,239,0.1);
  border: 1px solid rgba(124,111,239,0.2);
  padding: 0.25rem 0.75rem;
  border-radius: 99px;
  margin-bottom: 0.75rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.section-title {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--text);
}

.scholar-cta {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  margin-top: 0.75rem;
  color: var(--accent2);
  font-size: 0.9rem;
  font-weight: 500;
  transition: gap 0.2s;
}
.scholar-cta:hover { gap: 0.75rem; }

/* ========================================
   ABOUT
======================================== */
#about { background: var(--bg-card); }

.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: start;
}

.about-text p {
  color: var(--text-muted);
  margin-bottom: 1rem;
  font-size: 0.97rem;
}
.about-text strong { color: var(--text); }

.chip-group {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}

.chip {
  padding: 0.35rem 0.85rem;
  border-radius: 99px;
  font-size: 0.8rem;
  font-weight: 600;
  border: 1px solid;
}
.chip-blue   { background: rgba(124,111,239,0.12); border-color: rgba(124,111,239,0.3); color: #a89cf7; }
.chip-purple { background: rgba(168,85,247,0.12);  border-color: rgba(168,85,247,0.3);  color: #c084fc; }
.chip-green  { background: rgba(94,234,212,0.1);   border-color: rgba(94,234,212,0.25); color: var(--accent2); }
.chip-orange { background: rgba(251,146,60,0.1);   border-color: rgba(251,146,60,0.25); color: #fb923c; }
.chip-pink   { background: rgba(244,114,182,0.1);  border-color: rgba(244,114,182,0.25);color: #f472b6; }

/* ========================================
   EDUCATION / TIMELINE
======================================== */
.timeline { position: relative; padding-left: 1.5rem; }
.timeline::before {
  content: '';
  position: absolute; left: 0; top: 0; bottom: 0;
  width: 2px;
  background: linear-gradient(to bottom, var(--accent), var(--accent2));
  border-radius: 2px;
}

.timeline-item { position: relative; margin-bottom: 2rem; }

.timeline-dot {
  position: absolute;
  left: -1.5rem;
  top: 1.2rem;
  width: 12px; height: 12px;
  background: var(--accent);
  border-radius: 50%;
  border: 2px solid var(--bg);
  box-shadow: 0 0 10px var(--accent);
  transform: translateX(-5px);
}

.timeline-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  transition: border-color 0.2s, box-shadow 0.2s;
}
.timeline-card:hover {
  border-color: var(--border-h);
  box-shadow: var(--shadow);
}

.timeline-card-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 1rem;
  margin-bottom: 0.5rem;
}

.timeline-card-header h3 {
  font-size: 1.05rem;
  font-weight: 700;
}

.timeline-org {
  color: var(--accent);
  font-size: 0.88rem;
  font-weight: 500;
  margin-top: 0.2rem;
}

.timeline-date {
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--text-dim);
  white-space: nowrap;
  background: var(--bg-card2);
  padding: 0.25rem 0.6rem;
  border-radius: 6px;
}

.timeline-location {
  font-size: 0.82rem;
  color: var(--text-dim);
  margin-bottom: 0.75rem;
}
.timeline-location i { margin-right: 0.35rem; color: var(--accent3); }

.timeline-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}
.tag {
  font-size: 0.75rem;
  padding: 0.2rem 0.6rem;
  border-radius: 6px;
  background: rgba(255,255,255,0.05);
  color: var(--text-muted);
  border: 1px solid var(--border);
}

/* ========================================
   PROJECTS
======================================== */
#projects { background: var(--bg-card); }

.projects-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

.project-card {
  background: var(--bg-card2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  position: relative;
  transition: border-color 0.25s, transform 0.25s, box-shadow 0.25s;
  display: flex;
  flex-direction: column;
}
.project-card:hover {
  border-color: var(--border-h);
  transform: translateY(-4px);
  box-shadow: var(--shadow);
}

.project-card.featured {
  border-color: rgba(124,111,239,0.35);
  background: linear-gradient(135deg, rgba(124,111,239,0.06), rgba(94,234,212,0.04));
}

.featured-badge {
  display: inline-block;
  align-self: flex-start;
  margin-bottom: 0.75rem;
  font-size: 0.68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 0.2rem 0.6rem;
  border-radius: 99px;
  background: var(--gradient);
  color: #fff;
}

.project-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 0.75rem;
}

.project-icon {
  width: 42px; height: 42px;
  border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  font-size: 1.1rem;
}
.project-icon-blue   { background: rgba(124,111,239,0.15); color: #a89cf7; }
.project-icon-purple { background: rgba(168,85,247,0.15);  color: #c084fc; }
.project-icon-green  { background: rgba(94,234,212,0.12);  color: var(--accent2); }

.project-year {
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--text-dim);
  background: var(--bg-card);
  padding: 0.2rem 0.55rem;
  border-radius: 6px;
  border: 1px solid var(--border);
}

.project-card h3 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 0.3rem;
}

.project-stack {
  font-size: 0.78rem;
  color: var(--accent);
  font-weight: 500;
  margin-bottom: 0.75rem;
  font-family: var(--mono);
}

.project-bullets {
  list-style: none;
  flex: 1;
}
.project-bullets li {
  font-size: 0.83rem;
  color: var(--text-muted);
  padding-left: 1rem;
  position: relative;
  margin-bottom: 0.45rem;
}
.project-bullets li::before {
  content: '▸';
  position: absolute;
  left: 0;
  color: var(--accent2);
}
.project-bullets strong { color: var(--text); }

.project-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  margin-top: 1rem;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--accent);
  border: 1px solid rgba(124,111,239,0.3);
  padding: 0.35rem 0.85rem;
  border-radius: var(--radius-sm);
  transition: background 0.2s, border-color 0.2s;
  align-self: flex-start;
}
.project-link:hover {
  background: rgba(124,111,239,0.12);
  border-color: var(--accent);
}

/* ========================================
   PUBLICATIONS
======================================== */
.pubs-list {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.pub-card {
  display: flex;
  gap: 1.25rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  transition: border-color 0.2s, box-shadow 0.2s;
  align-items: flex-start;
}
.pub-card:hover {
  border-color: var(--border-h);
  box-shadow: var(--shadow);
}

.pub-year-badge {
  font-family: var(--mono);
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--accent);
  background: rgba(124,111,239,0.1);
  border: 1px solid rgba(124,111,239,0.2);
  padding: 0.35rem 0.7rem;
  border-radius: 8px;
  white-space: nowrap;
  min-width: fit-content;
  margin-top: 2px;
}

.pub-body { flex: 1; }

.pub-body h3 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 0.4rem;
  line-height: 1.4;
}

.pub-authors {
  font-size: 0.83rem;
  color: var(--text-muted);
  margin-bottom: 0.35rem;
}

.pub-venue {
  font-size: 0.8rem;
  color: var(--text-dim);
  margin-bottom: 0.75rem;
}
.pub-venue i { margin-right: 0.35rem; color: var(--accent3); }

.pub-links {
  display: flex;
  gap: 0.6rem;
  flex-wrap: wrap;
}

.pub-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.78rem;
  font-weight: 600;
  padding: 0.3rem 0.75rem;
  border-radius: var(--radius-sm);
  border: 1px solid;
  transition: background 0.2s;
}
.pub-link-ieee   { color: #00629B; border-color: rgba(0,98,155,0.4); background: rgba(0,98,155,0.08); }
.pub-link-ieee:hover { background: rgba(0,98,155,0.18); }
.pub-link-scholar { color: var(--accent2); border-color: rgba(94,234,212,0.3); background: rgba(94,234,212,0.06); }
.pub-link-scholar:hover { background: rgba(94,234,212,0.14); }

/* ========================================
   SKILLS
======================================== */
#skills { background: var(--bg-card); }

.skills-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.25rem;
}

.skill-category {
  background: var(--bg-card2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  transition: border-color 0.2s, transform 0.2s;
}
.skill-category:hover {
  border-color: var(--border-h);
  transform: translateY(-3px);
}

.skill-icon {
  width: 38px; height: 38px;
  border-radius: 9px;
  display: flex; align-items: center; justify-content: center;
  font-size: 1rem;
  background: rgba(124,111,239,0.12);
  color: var(--accent);
  margin-bottom: 0.85rem;
}

.skill-category h3 {
  font-size: 0.95rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
}

.skill-items {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.skill-item {
  font-size: 0.75rem;
  font-weight: 500;
  padding: 0.25rem 0.6rem;
  border-radius: 6px;
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--border);
  color: var(--text-muted);
  font-family: var(--mono);
}

/* ========================================
   FOOTER
======================================== */
#footer {
  padding: 3rem 0;
  border-top: 1px solid var(--border);
}

.footer-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
  text-align: center;
}

.footer-name {
  font-weight: 700;
  font-size: 1.05rem;
  background: var(--gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.footer-links {
  display: flex;
  gap: 1rem;
}
.footer-links a {
  width: 40px; height: 40px;
  border-radius: 50%;
  border: 1px solid var(--border);
  display: flex; align-items: center; justify-content: center;
  color: var(--text-muted);
  font-size: 0.95rem;
  transition: color 0.2s, border-color 0.2s, background 0.2s;
}
.footer-links a:hover {
  color: var(--accent);
  border-color: var(--accent);
  background: rgba(124,111,239,0.1);
}

.footer-copy {
  font-size: 0.78rem;
  color: var(--text-dim);
}

/* ========================================
   SCROLL REVEAL
======================================== */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.55s ease, transform 0.55s ease;
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ========================================
   RESPONSIVE
======================================== */
@media (max-width: 900px) {
  .projects-grid { grid-template-columns: 1fr 1fr; }
  .skills-grid   { grid-template-columns: 1fr 1fr; }
  .stats-grid    { grid-template-columns: 1fr 1fr; }
  .about-grid    { grid-template-columns: 1fr; }
}

@media (max-width: 640px) {
  .projects-grid { grid-template-columns: 1fr; }
  .skills-grid   { grid-template-columns: 1fr; }
  .nav-links     { display: none; flex-direction: column; position: absolute; top: 64px; left: 0; right: 0;
                   background: rgba(10,10,15,0.97); border-bottom: 1px solid var(--border); padding: 1rem; gap: 0.25rem; }
  .nav-links.open { display: flex; }
  .hamburger     { display: flex; }
  .pub-card      { flex-direction: column; }
  .pub-year-badge { align-self: flex-start; }
  .stats-grid    { grid-template-columns: 1fr 1fr; }
  section        { padding: 4rem 0; }
}