/* ============================================================
   STYLE — Main Stylesheet
   ============================================================ */

/* ---- Reset & Base ---- */

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

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

body {
  font-family: var(--font-sans);
  color: var(--text-primary);
  background-color: var(--bg-primary);
  line-height: 1.6;
  overflow-x: hidden;
}

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

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

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

ul, ol {
  list-style: none;
}

::selection {
  background: var(--accent);
  color: var(--text-inverse);
}

/* ---- Skip Link (Accessibility) ---- */

.skip-link {
  position: absolute;
  top: -100%;
  left: 16px;
  z-index: 10001;
  padding: 12px 24px;
  background: var(--accent);
  color: #fff;
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  font-weight: 600;
  text-decoration: none;
  transition: top 0.2s ease;
}

.skip-link:focus {
  top: 8px;
  color: #fff;
}

/* ---- Focus Styles (Accessibility) ---- */

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* Remove outline for mouse clicks */
:focus:not(:focus-visible) {
  outline: none;
}

/* ---- Typography ---- */

h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.02em;
  color: var(--text-primary);
  text-wrap: balance;
}

.heading-xl {
  font-size: clamp(2.5rem, 6vw, 5rem);
  letter-spacing: -0.04em;
  line-height: 1.05;
}

.heading-lg {
  font-size: clamp(2rem, 4vw, 3.5rem);
  letter-spacing: -0.03em;
}

.heading-md {
  font-size: clamp(1.5rem, 3vw, 2rem);
}

.heading-sm {
  font-size: clamp(1.125rem, 2vw, 1.5rem);
}

.text-lg {
  font-size: clamp(1.125rem, 1.8vw, 1.375rem);
  line-height: 1.5;
}

.text-md {
  font-size: 1rem;
  line-height: 1.6;
}

.text-sm {
  font-size: 0.875rem;
  line-height: 1.5;
}

.text-secondary {
  color: var(--text-secondary);
}

.text-tertiary {
  color: var(--text-tertiary);
}

.text-accent {
  color: var(--accent);
}

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

/* ---- Layout ---- */

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

.container-narrow {
  max-width: 800px;
}

.container-wide {
  max-width: 1400px;
}

.section {
  padding: var(--section-spacing) 0;
  position: relative;
}

.section-alt {
  background-color: var(--bg-secondary);
}

.section-header {
  text-align: center;
  margin-bottom: 64px;
}

.section-header .heading-lg {
  margin-bottom: 16px;
}

.section-header .text-lg {
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto;
}

.grid {
  display: grid;
  gap: 24px;
}

.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

.flex {
  display: flex;
}

.flex-center {
  display: flex;
  align-items: center;
  justify-content: center;
}

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

/* ---- Navigation ---- */

.nav-bar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  z-index: 1000;
  background-color: var(--bg-nav);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--text-primary);
  text-decoration: none;
  letter-spacing: -0.02em;
  white-space: nowrap;
}

.nav-logo:hover {
  color: var(--text-primary);
}

.nav-logo-img {
  height: 36px;
  width: auto;
}

/* Logo is designed for dark backgrounds — invert for light mode */
[data-theme="light"] .nav-logo-img {
  filter: invert(1);
}

[data-theme="dark"] .nav-logo-img {
  filter: none;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-link {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-secondary);
  text-decoration: none;
  transition: color var(--transition-fast);
  position: relative;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent);
  transition: width var(--transition-base);
}

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

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

.nav-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.nav-toggle-btn {
  background: none;
  border: none;
  cursor: pointer;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
  transition: background-color var(--transition-fast),
              color var(--transition-fast),
              transform 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.nav-toggle-btn:hover {
  background-color: var(--accent-light);
  color: var(--accent);
}

.nav-toggle-btn svg {
  width: 20px;
  height: 20px;
  transition: transform 0.4s cubic-bezier(0.34, 1.56, 0.64, 1),
              opacity 0.3s ease;
}

.lang-toggle {
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-strong);
  background: transparent;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.lang-toggle:hover {
  background: var(--accent-light);
  border-color: var(--accent);
  color: var(--accent);
}

/* Mobile Nav */
.nav-mobile-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  color: var(--text-primary);
  width: 36px;
  height: 36px;
  align-items: center;
  justify-content: center;
}

.nav-mobile-toggle svg {
  width: 24px;
  height: 24px;
}

.nav-mobile-menu {
  display: flex;
  position: fixed;
  top: var(--nav-height);
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--bg-primary);
  z-index: 999;
  padding: 40px 24px;
  flex-direction: column;
  gap: 24px;
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transform: translateY(-10px);
  transition: opacity var(--transition-base), transform var(--transition-base), visibility var(--transition-base);
}

.nav-mobile-menu.open {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transform: translateY(0);
}

.nav-mobile-menu .nav-link {
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--text-primary);
  opacity: 0;
  transform: translateX(-20px);
  transition: opacity 0.3s ease, transform 0.3s ease, color var(--transition-fast);
}

.nav-mobile-menu.open .nav-link:nth-child(1) { opacity: 1; transform: none; transition-delay: 0.05s; }
.nav-mobile-menu.open .nav-link:nth-child(2) { opacity: 1; transform: none; transition-delay: 0.10s; }
.nav-mobile-menu.open .nav-link:nth-child(3) { opacity: 1; transform: none; transition-delay: 0.15s; }
.nav-mobile-menu.open .nav-link:nth-child(4) { opacity: 1; transform: none; transition-delay: 0.20s; }
.nav-mobile-menu.open .nav-link:nth-child(5) { opacity: 1; transform: none; transition-delay: 0.25s; }
.nav-mobile-menu.open .nav-link:nth-child(6) { opacity: 1; transform: none; transition-delay: 0.30s; }

.nav-mobile-menu .nav-link::after {
  display: none;
}

/* ---- Buttons ---- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: var(--radius-xl);
  font-size: 0.9375rem;
  font-weight: 600;
  font-family: var(--font-sans);
  cursor: pointer;
  border: none;
  text-decoration: none;
  white-space: nowrap;
}

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

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

.btn-secondary {
  background: transparent;
  color: var(--accent);
  border: 1px solid var(--accent);
}

.btn-secondary:hover {
  background: var(--accent-light);
  color: var(--accent);
}

.btn-ghost {
  background: transparent;
  color: var(--accent);
  padding: 8px 0;
}

.btn-ghost:hover {
  color: var(--accent-hover);
}

.btn-ghost svg {
  transition: transform var(--transition-fast);
}

.btn-ghost:hover svg {
  transform: translateX(4px);
}

.btn-sm {
  padding: 6px 16px;
  font-size: 0.8125rem;
  border-radius: var(--radius-md);
}

.btn-group {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* ---- Logo in Hero ---- */

.hero-logo {
  width: 120px;
  height: auto;
  margin-bottom: 24px;
}

[data-theme="light"] .hero-logo {
  filter: invert(1);
}

[data-theme="dark"] .hero-logo {
  filter: none;
}

/* ---- Hero Section ---- */

.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
  padding-top: var(--nav-height);
  background: var(--bg-hero);
}

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

/* Mouse-follow radial gradient */
.hero-bg-mouse {
  position: absolute;
  inset: 0;
  opacity: 0;
  background: radial-gradient(600px circle at var(--mx, 50%) var(--my, 50%), rgba(41, 151, 255, 0.08), transparent 60%);
  transition: opacity 0.5s ease;
  pointer-events: none;
}

.hero:hover .hero-bg-mouse {
  opacity: 1;
}

.hero-bg-gradient {
  position: absolute;
  width: 600px;
  height: 600px;
  border-radius: 50%;
  filter: blur(120px);
  opacity: 0.15;
}

.hero-bg-gradient-1 {
  background: var(--accent);
  top: -200px;
  right: -100px;
}

.hero-bg-gradient-2 {
  background: #a855f7;
  bottom: -200px;
  left: -100px;
}

/* Hero Background Logo Watermark */
.hero-bg-logo {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%) scale(1);
  width: 60vh;
  height: auto;
  opacity: 0.10;
  pointer-events: none;
  z-index: 0;
  transition: none;
  will-change: transform, opacity;
  filter: drop-shadow(0 0 80px rgba(41, 151, 255, 0.15));
}

[data-theme="light"] .hero-bg-logo {
  filter: invert(1) drop-shadow(0 0 80px rgba(0, 113, 227, 0.12));
  opacity: 0.12;
}

[data-theme="dark"] .hero-bg-logo {
  filter: drop-shadow(0 0 80px rgba(41, 151, 255, 0.15));
}

.hero-content {
  position: relative;
  z-index: 1;
  text-align: center;
  max-width: 900px;
  padding: 40px 24px;
}

.hero-greeting {
  font-size: clamp(1rem, 1.5vw, 1.25rem);
  color: var(--accent);
  font-weight: 600;
  margin-bottom: 16px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.hero-headline {
  margin-bottom: 24px;
}

.hero-subline {
  font-size: clamp(1.125rem, 2vw, 1.375rem);
  color: var(--text-secondary);
  max-width: 640px;
  margin: 0 auto 40px;
  line-height: 1.5;
}

.hero-cta {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

/* ---- Services Section ---- */

.services-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.service-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 36px;
  position: relative;
  overflow: hidden;
  /* Scroll-driven reveal */
  opacity: 0;
  transform: translateY(40px) scale(0.97);
  transition: opacity 0.7s cubic-bezier(0.16, 1, 0.3, 1),
              transform 0.7s cubic-bezier(0.16, 1, 0.3, 1),
              background 0.3s ease,
              border-color 0.3s ease;
}

.service-card.service-visible {
  opacity: 1;
  transform: translateY(0) scale(1);
}

.service-card:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-strong);
}

/* Shine sweep effect on hover */
.service-card::after {
  content: '';
  position: absolute;
  top: -50%;
  left: -60%;
  width: 40%;
  height: 200%;
  background: linear-gradient(105deg, transparent 40%, rgba(255,255,255,0.08) 45%, rgba(255,255,255,0.12) 50%, rgba(255,255,255,0.08) 55%, transparent 60%);
  transform: skewX(-15deg);
  opacity: 0;
  transition: none;
  pointer-events: none;
}

.service-card:hover::after {
  opacity: 1;
  left: 130%;
  transition: left 0.6s ease, opacity 0.1s ease;
}

/* 3D tilt perspective */
.services-grid {
  perspective: 800px;
}

.service-icon {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-md);
  background: var(--accent-light);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  color: var(--accent);
}

.service-icon svg {
  width: 28px;
  height: 28px;
  transition: transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.service-card:hover .service-icon svg {
  transform: scale(1.15) rotate(6deg);
}

.service-card h3 {
  font-size: 1.25rem;
  margin-bottom: 12px;
}

.service-card p {
  color: var(--text-secondary);
  font-size: 0.9375rem;
  line-height: 1.6;
  margin-bottom: 16px;
}

.service-highlights {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.service-highlight-tag {
  font-size: 0.75rem;
  font-weight: 500;
  padding: 4px 12px;
  border-radius: 100px;
  background: var(--accent-light);
  color: var(--accent);
  opacity: 0;
  transform: translateY(8px);
  transition: opacity 0.4s ease, transform 0.4s ease, background-color 0.2s ease, color 0.2s ease;
}

.service-visible .service-highlight-tag {
  opacity: 1;
  transform: translateY(0);
}

.service-visible .service-highlight-tag:nth-child(1) { transition-delay: 0.3s; }
.service-visible .service-highlight-tag:nth-child(2) { transition-delay: 0.4s; }
.service-visible .service-highlight-tag:nth-child(3) { transition-delay: 0.5s; }

.service-highlight-tag:hover {
  background: var(--accent);
  color: #fff;
}

/* ---- About Section ---- */

.about-grid {
  display: grid;
  grid-template-columns: 1fr 1.5fr;
  gap: 64px;
  align-items: center;
}

.about-image-wrapper {
  position: relative;
  display: flex;
  justify-content: center;
}

.about-image {
  width: 100%;
  max-width: 360px;
  aspect-ratio: 1;
  object-fit: cover;
  object-position: center top;
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-lg);
  clip-path: circle(0% at 50% 50%);
  transition: clip-path 1.2s cubic-bezier(0.16, 1, 0.3, 1);
}

.reveal-slide-left.revealed .about-image,
.about-image.img-revealed {
  clip-path: circle(75% at 50% 50%);
}

.about-text h2 {
  margin-bottom: 24px;
}

.about-bio {
  color: var(--text-secondary);
  font-size: 1.0625rem;
  line-height: 1.7;
  margin-bottom: 40px;
}

.stats-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-bottom: 48px;
}

.stat-item {
  text-align: center;
  padding: 20px;
  background: var(--bg-secondary);
  border-radius: var(--radius-md);
  transition: transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1),
              box-shadow 0.3s ease;
}

.stat-item:hover {
  transform: scale(1.06);
  box-shadow: 0 4px 24px rgba(0, 113, 227, 0.12);
}

[data-theme="dark"] .stat-item:hover {
  box-shadow: 0 4px 24px rgba(41, 151, 255, 0.15);
}

.stat-number {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--accent);
  line-height: 1;
  margin-bottom: 4px;
}

.stat-label {
  font-size: 0.8125rem;
  color: var(--text-tertiary);
  font-weight: 500;
}

/* Education */
.education-list {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.education-item {
  display: flex;
  align-items: center;
  gap: 16px;
}

.education-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--accent);
  flex-shrink: 0;
  position: relative;
}



.education-year {
  font-size: 0.8125rem;
  color: var(--accent);
  font-weight: 600;
}

.education-degree {
  font-weight: 600;
  font-size: 0.9375rem;
}

.education-institution {
  color: var(--text-secondary);
  font-size: 0.875rem;
}

/* ---- Experience / Timeline ---- */

.timeline {
  position: relative;
  max-width: 800px;
  margin: 0 auto;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 24px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--border);
  transform-origin: top;
  transform: scaleY(0);
  transition: transform 1.5s cubic-bezier(0.16, 1, 0.3, 1);
}

.timeline.timeline-active::before {
  transform: scaleY(1);
}

.timeline-item {
  position: relative;
  padding-left: 64px;
  padding-bottom: 48px;
}

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

.timeline-dot {
  position: absolute;
  left: 16px;
  top: 4px;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--text-tertiary);
  border: 3px solid var(--bg-primary);
  box-shadow: 0 0 0 2px var(--text-tertiary);
  z-index: 1;
  transition: background 0.5s ease, box-shadow 0.5s ease;
}

.timeline-item.revealed .timeline-dot {
  background: var(--accent);
  box-shadow: 0 0 0 2px var(--accent);
}

.timeline-item:first-child .timeline-dot {
  width: 22px;
  height: 22px;
  left: 14px;
  top: 2px;
}

.timeline-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
  margin-bottom: 8px;
}

.timeline-period {
  font-size: 0.8125rem;
  color: var(--accent);
  font-weight: 600;
}

.timeline-location {
  font-size: 0.8125rem;
  color: var(--text-tertiary);
}

.timeline-role {
  font-size: 1.125rem;
  font-weight: 700;
  margin-bottom: 4px;
}

.timeline-company {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  margin-bottom: 12px;
}

.timeline-company a {
  color: var(--text-secondary);
  text-decoration: underline;
  text-decoration-color: var(--border);
  text-underline-offset: 2px;
}

.timeline-company a:hover {
  color: var(--accent);
  text-decoration-color: var(--accent);
}

.timeline-description {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.timeline-description li {
  font-size: 0.875rem;
  color: var(--text-secondary);
  padding-left: 16px;
  position: relative;
}

.timeline-description li::before {
  content: '— ';
  position: absolute;
  left: 0;
  color: var(--text-tertiary);
}

.timeline-description li {
  padding-left: 24px;
}

/* ---- Publications ---- */

.pub-featured {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 48px;
  margin-bottom: 48px;
  position: relative;
}

.pub-featured-label {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 16px;
}

.pub-featured h3 {
  font-size: 1.5rem;
  margin-bottom: 12px;
  line-height: 1.3;
}

.pub-authors {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-bottom: 8px;
}

.pub-venue {
  font-size: 0.8125rem;
  color: var(--accent);
  font-weight: 600;
  margin-bottom: 16px;
}

.pub-abstract {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 20px;
}

.pub-links {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.pub-link {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 6px 14px;
  border-radius: var(--radius-sm);
  font-size: 0.8125rem;
  font-weight: 500;
  background: var(--accent-light);
  color: var(--accent);
  transition: background-color var(--transition-fast);
}

.pub-link:hover {
  background: var(--accent);
  color: #fff;
}

/* Publication list items */
.pub-list {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.pub-list-item {
  padding: 24px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  background: var(--bg-card);
  transition: border-color var(--transition-fast);
}

.pub-list-item:hover {
  border-color: var(--border-strong);
}

.pub-list-item h4 {
  font-size: 1rem;
  margin-bottom: 8px;
  line-height: 1.4;
}

.pub-list-item .pub-authors {
  margin-bottom: 4px;
}

/* ---- Contact Section ---- */

/* ---- Gallery Section ---- */

.gallery-carousel {
  position: relative;
  overflow: hidden;
  -webkit-mask-image: linear-gradient(90deg, transparent, black 5%, black 95%, transparent);
  mask-image: linear-gradient(90deg, transparent, black 5%, black 95%, transparent);
}

.gallery-track {
  display: flex;
  gap: 24px;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  scroll-behavior: smooth;
  -webkit-overflow-scrolling: touch;
  padding-bottom: 16px;
  scrollbar-width: none;
}

.gallery-track::-webkit-scrollbar {
  display: none;
}

.gallery-item {
  flex: 0 0 auto;
  width: 340px;
  scroll-snap-align: start;
  cursor: pointer;
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--bg-card);
  border: 1px solid var(--border);
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.gallery-item:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.gallery-item img {
  width: 100%;
  height: 240px;
  object-fit: cover;
  display: block;
}

.gallery-caption {
  padding: 14px 18px;
  font-size: 0.875rem;
  color: var(--text-secondary);
  text-align: center;
  font-weight: 500;
}

.gallery-nav {
  display: flex;
  justify-content: center;
  gap: 12px;
  margin-top: 24px;
}

.gallery-nav-btn {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--bg-card);
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.gallery-nav-btn:hover {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

.gallery-nav-btn svg {
  width: 20px;
  height: 20px;
}

/* Gallery Lightbox */

.gallery-lightbox {
  position: fixed;
  inset: 0;
  z-index: 10000;
  background: rgba(0, 0, 0, 0.9);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s ease, visibility 0.3s ease;
}

.gallery-lightbox.open {
  opacity: 1;
  visibility: visible;
}

.gallery-lightbox-close {
  position: absolute;
  top: 20px;
  right: 20px;
  background: rgba(255, 255, 255, 0.1);
  border: none;
  color: #fff;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: background var(--transition-fast);
  z-index: 1;
}

.gallery-lightbox-close:hover {
  background: rgba(255, 255, 255, 0.25);
}

.gallery-lightbox-img {
  max-width: 90vw;
  max-height: 80vh;
  object-fit: contain;
  border-radius: var(--radius-md);
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
  transform: scale(0.9);
  filter: blur(8px);
  transition: transform 0.4s cubic-bezier(0.16, 1, 0.3, 1),
              filter 0.4s ease;
}

.gallery-lightbox.open .gallery-lightbox-img {
  transform: scale(1);
  filter: blur(0);
}

.gallery-lightbox-caption {
  color: rgba(255, 255, 255, 0.85);
  font-size: 0.9375rem;
  margin-top: 16px;
  text-align: center;
  max-width: 600px;
  padding: 0 24px;
}

/* ---- Contact Grid ---- */

.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: start;
}

.contact-info h2 {
  margin-bottom: 16px;
}

.contact-description {
  color: var(--text-secondary);
  font-size: 1.0625rem;
  line-height: 1.6;
  margin-bottom: 32px;
}

.contact-details {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.contact-detail {
  display: flex;
  align-items: center;
  gap: 16px;
}

.contact-detail-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  background: var(--accent-light);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent);
  flex-shrink: 0;
}

.contact-detail-icon svg {
  width: 20px;
  height: 20px;
}

.contact-detail-text {
  font-size: 0.9375rem;
}

.contact-detail-label {
  font-size: 0.75rem;
  color: var(--text-tertiary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 2px;
}

.contact-social {
  display: flex;
  gap: 12px;
  margin-top: 32px;
}

.social-link {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
  transition: all var(--transition-fast);
  position: relative;
  overflow: hidden;
}

.social-link::before {
  content: '';
  position: absolute;
  inset: 0;
  background: var(--accent);
  border-radius: inherit;
  transform: scale(0);
  transition: transform 0.35s cubic-bezier(0.34, 1.56, 0.64, 1);
  z-index: 0;
}

.social-link:hover::before {
  transform: scale(1);
}

.social-link:hover {
  border-color: var(--accent);
  color: #fff;
}

.social-link svg {
  position: relative;
  z-index: 1;
}

.social-link svg {
  width: 22px;
  height: 22px;
}

.contact-cta-card {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 48px;
  text-align: center;
  position: relative;
  border: 1px solid var(--border);
}

.contact-cta-card h3 {
  font-size: 1.5rem;
  margin-bottom: 12px;
}

.contact-cta-card p {
  color: var(--text-secondary);
  margin-bottom: 28px;
}

/* ---- Footer ---- */

.footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border);
  padding: 40px 0;
}

.footer-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  text-align: center;
}

.footer-links {
  display: flex;
  gap: 24px;
  flex-wrap: wrap;
  justify-content: center;
}

.footer-link {
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.footer-link:hover {
  color: var(--accent);
}

.footer-copyright {
  font-size: 0.8125rem;
  color: var(--text-tertiary);
}

/* ---- Subpage Layout (Impressum, Terms) ---- */

.subpage {
  padding-top: calc(var(--nav-height) + 60px);
  padding-bottom: var(--section-spacing);
  min-height: 100vh;
}

.subpage-content {
  max-width: 800px;
  margin: 0 auto;
}

.subpage-content h1 {
  font-size: clamp(2rem, 4vw, 3rem);
  margin-bottom: 40px;
}

.subpage-content h2 {
  font-size: 1.375rem;
  margin-top: 40px;
  margin-bottom: 16px;
}

.subpage-content h3 {
  font-size: 1.125rem;
  margin-top: 28px;
  margin-bottom: 12px;
}

.subpage-content h4 {
  font-size: 1rem;
  font-weight: 600;
  margin-top: 20px;
  margin-bottom: 8px;
}

.subpage-content p {
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 16px;
}

.subpage-content strong {
  color: var(--text-primary);
  font-weight: 600;
  font-size: 0.875rem;
  line-height: 1.6;
}

.subpage-content a {
  text-decoration: underline;
  text-underline-offset: 2px;
}

.subpage-back {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: 32px;
}

.subpage-back:hover {
  color: var(--accent);
}

/* ---- References / Testimonials ---- */

.references-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px;
}

.reference-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 36px;
  display: flex;
  flex-direction: column;
  gap: 20px;
  transition: transform var(--transition-base),
              box-shadow var(--transition-base),
              background-color var(--transition-base);
}

.reference-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  background: var(--bg-card-hover);
}

.reference-header {
  display: flex;
  align-items: center;
  gap: 16px;
}

.reference-logo {
  width: 48px;
  height: 48px;
  object-fit: contain;
  border-radius: var(--radius-sm);
  flex-shrink: 0;
}

.reference-logo-placeholder {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-sm);
  background: var(--accent-light);
  color: var(--accent);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 1.125rem;
  flex-shrink: 0;
  letter-spacing: -0.02em;
}

.reference-company {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.3;
}

.reference-role {
  font-size: 0.8125rem;
  color: var(--text-tertiary);
  font-weight: 500;
}

.reference-quote {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  line-height: 1.7;
  font-style: italic;
  position: relative;
  padding-left: 20px;
  border-left: 3px solid var(--accent);
}

.reference-quote::before {
  content: none;
}

.reference-author {
  font-size: 0.8125rem;
  color: var(--text-tertiary);
  font-weight: 500;
  margin-top: auto;
}

/* ---- Responsive ---- */

@media (max-width: 1024px) {
  .services-grid {
    grid-template-columns: 1fr;
  }

  .about-grid {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .about-image-wrapper {
    display: flex;
    justify-content: center;
  }

  .about-image {
    max-width: 300px;
  }

  .about-text {
    display: flex;
    flex-direction: column;
    align-items: center;
  }

  .about-bio {
    text-align: center;
  }

  .stats-row {
    width: 100%;
  }

  .education-list {
    align-items: flex-start;
    width: fit-content;
    margin: 0 auto;
  }

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

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

  .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  :root {
    --section-spacing: 80px;
    --nav-height: 56px;
  }

  .nav-links {
    display: none;
  }

  .nav-mobile-toggle {
    display: flex;
  }

  .hero-content {
    padding: 24px 16px;
  }

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

  .about-grid {
    gap: 40px;
  }

  .stats-row {
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
  }

  .stat-number {
    font-size: 1.75rem;
  }

  .contact-grid {
    gap: 40px;
  }

  .pub-featured {
    padding: 28px;
  }

  .gallery-item {
    width: 280px;
  }

  .gallery-item img {
    height: 200px;
  }

  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }

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

  .timeline::before {
    left: 16px;
  }

  .timeline-item {
    padding-left: 48px;
  }

  .timeline-dot {
    left: 8px;
  }

  .timeline-item:first-child .timeline-dot {
    left: 6px;
  }

  .btn-group {
    flex-direction: column;
  }
}

@media (max-width: 480px) {
  .stats-row {
    grid-template-columns: repeat(3, 1fr);
  }

  .footer-links {
    flex-direction: column;
    gap: 12px;
  }
}

/* ---- Scroll-to-Top Button ---- */

.scroll-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--bg-card);
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  z-index: 900;
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: opacity var(--transition-base),
              visibility var(--transition-base),
              transform var(--transition-base),
              background-color var(--transition-fast),
              color var(--transition-fast),
              border-color var(--transition-fast);
  box-shadow: var(--shadow-md);
}

.scroll-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.scroll-to-top:hover {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

.scroll-to-top svg {
  width: 20px;
  height: 20px;
}