/* ============================================================
   BIV-LAB – Shared Stylesheet
   ============================================================ */

/* ── Reset & Base ─────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --navy:    #06090f;
  --navy-2:  #0d1526;
  --navy-3:  #111d35;
  --blue:    #1c6ef3;
  --blue-2:  #2a7fff;
  --accent:  #00d4ff;
  --white:   #ffffff;
  --off-white: #e8edf5;
  --muted:   #8a99b8;
  --border:  rgba(255,255,255,0.08);
  --card-bg: rgba(255,255,255,0.04);
  --radius:  12px;
  --radius-sm: 6px;
  --shadow:  0 4px 32px rgba(0,0,20,0.5);
  --transition: 0.25s ease;
  --font: 'Inter', 'Segoe UI', system-ui, sans-serif;
}

html { scroll-behavior: smooth; }

body {
  font-family: var(--font);
  background: var(--navy);
  color: var(--off-white);
  line-height: 1.7;
  font-size: 16px;
}

a { color: var(--blue-2); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--accent); }

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

h1, h2, h3, h4, h5 {
  line-height: 1.25;
  font-weight: 700;
  color: var(--white);
}

h1 { font-size: clamp(2.2rem, 5vw, 3.6rem); }
h2 { font-size: clamp(1.6rem, 3.5vw, 2.4rem); }
h3 { font-size: clamp(1.1rem, 2vw, 1.4rem); }

p { color: var(--muted); margin-bottom: 1rem; }

ul { list-style: none; }

/* ── Utility ─────────────────────────────────────────────── */
.container {
  max-width: 1140px;
  margin: 0 auto;
  padding: 0 24px;
}

.section { padding: 80px 0; }

.section-label {
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 12px;
}

.section-title {
  margin-bottom: 16px;
}

.section-subtitle {
  color: var(--muted);
  font-size: 1.05rem;
  max-width: 600px;
  margin-bottom: 48px;
}

.btn {
  display: inline-block;
  padding: 13px 30px;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  transition: all var(--transition);
  border: 2px solid transparent;
}

.btn-primary {
  background: var(--blue);
  color: var(--white);
  border-color: var(--blue);
}
.btn-primary:hover {
  background: var(--blue-2);
  border-color: var(--blue-2);
  color: var(--white);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(28,110,243,0.35);
}

.btn-outline {
  background: transparent;
  color: var(--white);
  border-color: var(--border);
}
.btn-outline:hover {
  border-color: var(--blue-2);
  color: var(--blue-2);
}

.badge {
  display: inline-block;
  padding: 4px 12px;
  border-radius: 99px;
  font-size: 0.75rem;
  font-weight: 600;
  background: rgba(28,110,243,0.15);
  color: var(--accent);
  border: 1px solid rgba(0,212,255,0.2);
  margin-bottom: 16px;
}

.divider {
  border: none;
  border-top: 1px solid var(--border);
  margin: 48px 0;
}

/* ── Navbar ───────────────────────────────────────────────── */
.navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  background: rgba(6,9,15,0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
  transition: background var(--transition);
}

.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}

.nav-logo img { height: 44px; width: auto; }

.nav-links {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-links a {
  color: var(--off-white);
  font-size: 0.9rem;
  font-weight: 500;
  padding: 6px 14px;
  border-radius: var(--radius-sm);
  transition: all var(--transition);
}
.nav-links a:hover,
.nav-links a.active {
  color: var(--white);
  background: rgba(255,255,255,0.07);
}

.nav-cta { margin-left: 12px; }

.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 8px;
  background: none;
  border: none;
}
.hamburger span {
  display: block;
  width: 24px; height: 2px;
  background: var(--white);
  border-radius: 2px;
  transition: all var(--transition);
}
.hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; }
.hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

.nav-mobile {
  display: none;
  flex-direction: column;
  gap: 4px;
  padding: 16px 24px 20px;
  background: var(--navy-2);
  border-top: 1px solid var(--border);
}
.nav-mobile a {
  color: var(--off-white);
  font-size: 1rem;
  padding: 10px 0;
  border-bottom: 1px solid var(--border);
}
.nav-mobile a:last-child { border-bottom: none; }
.nav-mobile.show { display: flex; }

/* page offset for fixed navbar */
.page-content { padding-top: 68px; }

/* ── Hero layout (text + logo bubble) ────────────────────── */
.hero-layout {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 48px;
}

.hero-layout .hero-content { flex: 1; }

/* ── Logo bubble ──────────────────────────────────────────── */
.hero-logo-bubble {
  position: relative;
  flex-shrink: 0;
  width: 260px;
  height: 260px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.logo-circle {
  position: relative;
  z-index: 3;
  width: 160px;
  height: 160px;
  border-radius: 50%;
  background: radial-gradient(circle at 40% 35%, rgba(255,255,255,0.55), rgba(200,220,255,0.3));
  border: 2px solid rgba(255,255,255,0.6);
  backdrop-filter: blur(12px);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 0 40px rgba(28,110,243,0.4), 0 0 80px rgba(0,212,255,0.18), inset 0 1px 2px rgba(255,255,255,0.7);
}

.logo-circle img {
  width: 90px;
  height: auto;
  filter: drop-shadow(0 2px 8px rgba(0,40,120,0.25));
}

.logo-ring {
  position: absolute;
  border-radius: 50%;
  border: 1px solid rgba(28,110,243,0.25);
  animation: pulse-ring 3s ease-out infinite;
}
.logo-ring-1 { width: 190px; height: 190px; animation-delay: 0s; }
.logo-ring-2 { width: 225px; height: 225px; animation-delay: 0.7s; border-color: rgba(0,212,255,0.15); }
.logo-ring-3 { width: 260px; height: 260px; animation-delay: 1.4s; border-color: rgba(28,110,243,0.08); }

@keyframes pulse-ring {
  0%   { opacity: 0.8; transform: scale(0.95); }
  60%  { opacity: 0.3; transform: scale(1); }
  100% { opacity: 0;   transform: scale(1.03); }
}

@media (max-width: 680px) {
  .hero-layout { flex-direction: column; text-align: center; }
  .hero-layout .hero-content { text-align: center; }
  .hero-logo-bubble { width: 200px; height: 200px; }
  .logo-circle { width: 120px; height: 120px; }
  .logo-circle img { width: 68px; }
  .logo-ring-1 { width: 148px; height: 148px; }
  .logo-ring-2 { width: 174px; height: 174px; }
  .logo-ring-3 { width: 200px; height: 200px; }
}

/* ── Hero background image (index only) ──────────────────── */
.hero-bg {
  background:
    linear-gradient(to right, rgba(6,9,15,0.92) 40%, rgba(6,9,15,0.55) 100%),
    radial-gradient(ellipse 80% 60% at 50% 0%, rgba(28,110,243,0.18) 0%, transparent 70%),
    url('hero-bg.jpg') center center / cover no-repeat;
}

/* ── Hero ─────────────────────────────────────────────────── */
.hero {
  min-height: 90vh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
  background: radial-gradient(ellipse 80% 60% at 50% 0%, rgba(28,110,243,0.18) 0%, transparent 70%),
              radial-gradient(ellipse 60% 40% at 80% 70%, rgba(0,212,255,0.08) 0%, transparent 60%),
              var(--navy);
}

.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.02'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 700px;
}

.hero h1 { margin-bottom: 20px; }

.hero-sub {
  font-size: 1.1rem;
  color: var(--muted);
  margin-bottom: 36px;
  max-width: 540px;
}

.hero-buttons { display: flex; gap: 14px; flex-wrap: wrap; }

/* ── Page Hero (inner pages) ──────────────────────────────── */
.page-hero {
  padding: 80px 0 60px;
  background: radial-gradient(ellipse 70% 100% at 50% 0%, rgba(28,110,243,0.12) 0%, transparent 70%),
              var(--navy-2);
  border-bottom: 1px solid var(--border);
  text-align: center;
}
.page-hero h1 { margin-bottom: 12px; }
.page-hero p { margin: 0 auto; max-width: 560px; }

/* ── Cards ────────────────────────────────────────────────── */
.card-grid {
  display: grid;
  gap: 24px;
}
.card-grid-3 { grid-template-columns: repeat(3, 1fr); }
.card-grid-2 { grid-template-columns: repeat(2, 1fr); }

.card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  transition: all var(--transition);
}
.card:hover {
  border-color: rgba(28,110,243,0.35);
  transform: translateY(-4px);
  box-shadow: 0 12px 40px rgba(0,0,0,0.3);
}

.card-icon {
  width: 48px; height: 48px;
  background: rgba(28,110,243,0.15);
  border-radius: var(--radius-sm);
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 20px;
  font-size: 1.4rem;
}

.card h3 { margin-bottom: 10px; font-size: 1.15rem; }
.card p { font-size: 0.93rem; margin: 0; }

/* ── Split section (2-col with image) ────────────────────── */
.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}
.split.reverse { direction: rtl; }
.split.reverse > * { direction: ltr; }

.split-visual {
  border-radius: var(--radius);
  overflow: hidden;
  position: relative;
}
.split-visual img {
  width: 100%;
  border-radius: var(--radius);
  border: 1px solid var(--border);
}
.split-visual::after {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: var(--radius);
  background: linear-gradient(135deg, rgba(28,110,243,0.08), transparent);
  pointer-events: none;
}

/* ── CTA Banner ───────────────────────────────────────────── */
.cta-banner {
  background: linear-gradient(135deg, var(--navy-3) 0%, rgba(28,110,243,0.12) 100%);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 64px 48px;
  text-align: center;
}
.cta-banner h2 { margin-bottom: 12px; }
.cta-banner p { margin-bottom: 28px; }

/* ── Values ───────────────────────────────────────────────── */
.values-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.value-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px 28px;
  transition: all var(--transition);
}
.value-card:hover {
  border-color: rgba(28,110,243,0.3);
  transform: translateY(-3px);
}
.value-number {
  font-size: 2.5rem;
  font-weight: 800;
  color: rgba(28,110,243,0.25);
  line-height: 1;
  margin-bottom: 12px;
}
.value-card h3 { margin-bottom: 10px; }
.value-card p { font-size: 0.93rem; margin: 0; }

/* ── Resume ───────────────────────────────────────────────── */
.resume-layout {
  display: grid;
  grid-template-columns: 320px 1fr;
  gap: 40px;
  align-items: start;
}

.resume-sidebar {
  background: var(--navy-3);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  position: sticky;
  top: 88px;
}

.resume-avatar {
  width: 110px; height: 110px;
  border-radius: 50%;
  object-fit: cover;
  border: 3px solid var(--blue);
  margin: 0 auto 20px;
}

.resume-sidebar h3 {
  text-align: center;
  font-size: 1.1rem;
  margin-bottom: 4px;
}

.resume-sidebar .title {
  text-align: center;
  font-size: 0.85rem;
  color: var(--muted);
  margin-bottom: 24px;
}

.contact-item {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.88rem;
  color: var(--muted);
  margin-bottom: 10px;
}
.contact-item .icon { font-size: 1rem; }

.sidebar-section { margin-top: 24px; padding-top: 24px; border-top: 1px solid var(--border); }
.sidebar-section h4 { font-size: 0.75rem; letter-spacing: 0.1em; text-transform: uppercase; color: var(--accent); margin-bottom: 12px; }

.tag-list { display: flex; flex-wrap: wrap; gap: 6px; }
.tag {
  padding: 4px 10px;
  background: rgba(28,110,243,0.12);
  color: var(--blue-2);
  border-radius: 99px;
  font-size: 0.78rem;
  font-weight: 500;
  border: 1px solid rgba(28,110,243,0.2);
}

.resume-main {}

.resume-section { margin-bottom: 40px; }
.resume-section h2 {
  font-size: 1.3rem;
  margin-bottom: 20px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: 10px;
}
.resume-section h2 .icon { font-size: 1rem; color: var(--accent); }

.timeline-item {
  position: relative;
  padding-left: 24px;
  margin-bottom: 24px;
}
.timeline-item::before {
  content: '';
  position: absolute;
  left: 0; top: 8px;
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--blue);
}
.timeline-item::after {
  content: '';
  position: absolute;
  left: 3px; top: 20px;
  width: 2px; height: calc(100% + 4px);
  background: var(--border);
}
.timeline-item:last-child::after { display: none; }

.timeline-item h4 { font-size: 1rem; margin-bottom: 2px; }
.timeline-meta { font-size: 0.82rem; color: var(--accent); margin-bottom: 6px; }
.timeline-item p { font-size: 0.9rem; margin: 0; }

/* ── Publications ─────────────────────────────────────────── */
.pub-list { display: flex; flex-direction: column; gap: 20px; }

.pub-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 32px;
  transition: all var(--transition);
}
.pub-card:hover {
  border-color: rgba(28,110,243,0.3);
  transform: translateX(4px);
}
.pub-card h3 {
  font-size: 1.05rem;
  margin-bottom: 8px;
  line-height: 1.45;
}
.pub-meta {
  font-size: 0.82rem;
  color: var(--muted);
  margin-bottom: 12px;
}
.pub-meta strong { color: var(--off-white); }
.pub-tags { display: flex; flex-wrap: wrap; gap: 6px; }
.pub-tag {
  padding: 3px 10px;
  border-radius: 99px;
  font-size: 0.73rem;
  font-weight: 600;
}
.pub-tag.journal { background: rgba(0,212,255,0.12); color: var(--accent); }
.pub-tag.conference { background: rgba(28,110,243,0.15); color: var(--blue-2); }
.pub-tag.year { background: rgba(255,255,255,0.06); color: var(--muted); }

/* ── Scroll to top ────────────────────────────────────────── */
#scrollTop {
  position: fixed;
  bottom: 28px;
  right: 28px;
  z-index: 999;
  width: 44px; height: 44px;
  border-radius: 50%;
  background: var(--blue);
  color: var(--white);
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  opacity: 0;
  pointer-events: none;
  transition: all var(--transition);
  box-shadow: 0 4px 16px rgba(28,110,243,0.4);
}
#scrollTop.show { opacity: 1; pointer-events: auto; }
#scrollTop:hover { background: var(--blue-2); transform: translateY(-3px); }

/* ── Footer ───────────────────────────────────────────────── */
.footer {
  border-top: 1px solid var(--border);
  padding: 28px 0;
  text-align: center;
}
.footer p { font-size: 0.88rem; color: var(--muted); margin: 0; }

/* ── Responsive ───────────────────────────────────────────── */
@media (max-width: 960px) {
  .card-grid-3 { grid-template-columns: 1fr 1fr; }
  .values-grid  { grid-template-columns: 1fr 1fr; }
  .split        { grid-template-columns: 1fr; gap: 40px; }
  .split.reverse { direction: ltr; }
  .split-visual { order: -1; max-width: 480px; margin: 0 auto; }
  .resume-layout { grid-template-columns: 1fr; }
  .resume-sidebar { position: static; }
}

@media (max-width: 680px) {
  .card-grid-3 { grid-template-columns: 1fr; }
  .card-grid-2 { grid-template-columns: 1fr; }
  .values-grid  { grid-template-columns: 1fr; }
  .cta-banner   { padding: 40px 24px; }
  .nav-links, .nav-cta { display: none; }
  .hamburger { display: flex; }
  .hero { min-height: 80vh; }
}