/* ============================================================
   Components — Navigation, Cards, Overlay, Buttons
   ============================================================ */

/* === Navigation === */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  display: flex; align-items: center; justify-content: space-between;
  padding: var(--space-md) clamp(40px, 6vw, 100px);
  background: transparent;
  border-bottom: 1px solid transparent;
  transition: background-color var(--duration-slow) var(--ease-out),
              border-color var(--duration-slow) var(--ease-out);
}
.nav.scrolled {
  background: var(--surface-alt);
  border-bottom-color: var(--border-subtle);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}
.nav__logo {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  font-family: var(--font-sans);
  font-size: var(--text-caption);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
}
.nav__logo a {
  display: inline-flex;
  align-items: center;
  gap: var(--space-md);
  color: inherit;
}
.nav__logo img, .nav__logo svg {
  width: 42px;
  height: 42px;
  display: block;
  flex-shrink: 0;
}
.nav__logo span {
  font-family: var(--font-sans) !important;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.12em;
}
.nav__logo-text-mobile {
  display: none;
}
.nav__links {
  display: flex;
  gap: var(--space-lg);
  align-items: center;
}
.nav__links a {
  font-family: var(--font-mono);
  font-size: var(--text-caption);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--fg-secondary);
  transition: color var(--duration-fast) var(--ease-out);
  position: relative;
  padding-bottom: 4px;
  display: inline-flex;
  align-items: center;
}
.nav__links a:hover {
  color: var(--fg);
}
.nav__links a::after {
  content: '';
  position: absolute;
  bottom: 0; left: 0; right: 0;
  height: 2px;
  background: var(--accent);
  transform: scaleX(0);
  transition: transform var(--duration-normal) var(--ease-out);
  transform-origin: bottom left;
}
.nav__links a:hover::after {
  transform: scaleX(1);
}
.nav__links a.active {
  color: var(--accent) !important;
  font-weight: 600;
}
.nav__links a.active::after {
  transform: scaleX(1);
  background: var(--accent) !important;
}

.nav__link-icon {
  margin-right: 8px;
  font-size: 1.15em;
  color: var(--fg-muted);
  transition: transform var(--duration-normal) var(--ease-out), color var(--duration-fast) var(--ease-out);
  display: inline-block;
  line-height: 1;
}
.nav__links a:hover .nav__link-icon {
  color: var(--accent);
}
.nav__links a.active .nav__link-icon {
  color: var(--accent);
}

/* Hide nav link icons in the header menu (desktop) */
.nav__links:not(.open) .nav__link-icon {
  display: none;
}

/* Individual micro-animations for menu icons on hover */
.nav__links a[href*="news"]:hover .nav__link-icon {
  transform: rotate(90deg) scale(1.2);
}
.nav__links a[href*="focus"]:hover .nav__link-icon {
  transform: scale(1.25);
}
.nav__links a[href*="work"]:hover .nav__link-icon {
  transform: rotate(45deg) scale(1.15);
}
.nav__links a[href*="lab"]:hover .nav__link-icon {
  transform: rotate(180deg) scale(1.2);
}
.nav__links a[href*="career"]:hover .nav__link-icon {
  transform: scale(1.2) translateY(-2px);
}
.nav__links a[href*="videos"]:hover .nav__link-icon {
  transform: scale(1.2) translateX(2px);
}
.nav__links a[href*="about"]:hover .nav__link-icon {
  transform: scale(1.2) rotate(15deg);
}
.nav__links a[href^="mailto"]:hover .nav__link-icon {
  transform: translate(4px, -4px) scale(1.1);
}

/* Chinese nav text bolding */
[data-lang="zh"] .nav__links a,
[data-lang="zh"] .nav__lang-btn,
.nav .lang-zh,
.nav__logo-zh,
.nav__logo .lang-zh,
.nav__links a .lang-zh {
  font-weight: 700 !important;
  font-family: var(--font-sans) !important;
}
.nav__logo-zh,
.nav__logo .lang-zh {
  margin-left: 8px !important;
  color: var(--fg-secondary) !important;
  opacity: 0.8;
}

.nav__controls {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}
.nav__lang-btn {
  font-family: var(--font-mono);
  font-size: var(--text-caption);
  padding: 2px 6px;
  color: var(--fg-muted);
  border: 1px solid transparent;
  transition: all var(--duration-fast) var(--ease-out);
}
.nav__lang-btn.active {
  color: var(--fg);
  border-color: var(--border);
}
.nav__theme-toggle {
  font-size: 16px;
  padding: 2px 6px;
}

/* Mobile nav burger button and menu */
.nav__burger {
  display: none;
  width: 36px;
  height: 36px;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  z-index: 101;
}

.nav__burger span {
  display: block;
  width: 20px;
  height: 1.5px;
  background: var(--fg);
  transition: all var(--duration-fast) var(--ease-out);
}

.nav__burger.open span:nth-child(1) {
  transform: translateY(6.5px) rotate(45deg);
}

.nav__burger.open span:nth-child(2) {
  opacity: 0;
}

.nav__burger.open span:nth-child(3) {
  transform: translateY(-6.5px) rotate(-45deg);
}

@media (max-width: 768px) {
  .nav__logo-text-full {
    display: none;
  }
  .nav__logo-text-mobile {
    display: inline;
  }
  .nav__links {
    display: none;
  }
  .nav__burger {
    display: flex;
  }
  .nav__links.open {
    display: flex;
    flex-direction: column;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 100vh;
    background: var(--overlay-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    padding: var(--space-5xl) clamp(40px, 6vw, 100px) var(--space-xl);
    gap: var(--space-md);
    z-index: 99;
    justify-content: center;
    align-items: flex-start;
    border-bottom: 1px solid var(--border-subtle);
    animation: mobileMenuFadeIn 0.35s var(--ease-out) forwards;
  }
  .nav__links.open a {
    font-size: var(--text-h3);
    letter-spacing: 0.04em;
    width: 100%;
    padding: var(--space-sm) 0;
    border-bottom: 1px dashed var(--border-subtle);
    opacity: 0;
    transform: translateY(15px);
    animation: mobileLinkStaggerIn 0.4s var(--ease-out) forwards;
  }
  .nav__links.open a:last-child {
    border-bottom: none;
  }
  .nav__links.open a:nth-child(1) { animation-delay: 0.06s; }
  .nav__links.open a:nth-child(2) { animation-delay: 0.11s; }
  .nav__links.open a:nth-child(3) { animation-delay: 0.16s; }
  .nav__links.open a:nth-child(4) { animation-delay: 0.21s; }
  .nav__links.open a:nth-child(5) { animation-delay: 0.26s; }
  .nav__links.open a:nth-child(6) { animation-delay: 0.31s; }
  .nav__links.open a:nth-child(7) { animation-delay: 0.36s; }
  .nav__links.open a:nth-child(8) { animation-delay: 0.41s; }
}

@keyframes mobileMenuFadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes mobileLinkStaggerIn {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* === Artwork Grid === */
.artwork-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  grid-auto-flow: dense;
  gap: 2px;
}

@media (max-width: 1024px) {
  .artwork-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 480px) {
  .artwork-grid { grid-template-columns: 1fr; }
}

.artwork-card {
  position: relative;
  overflow: hidden;
  aspect-ratio: 4 / 3;
  background: var(--surface);
  cursor: pointer;
}

.artwork-card__image {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--duration-slow) var(--ease-out);
  will-change: transform;
  backface-visibility: hidden;
}

.artwork-card:hover .artwork-card__image {
  transform: scale(1.03);
}

.artwork-card__info {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  padding: var(--space-lg);
  background: linear-gradient(transparent, rgba(0,0,0,0.7));
  opacity: 0;
  transform: translateY(8px);
  transition: all var(--duration-normal) var(--ease-out);
}

.artwork-card:hover .artwork-card__info {
  opacity: 1;
  transform: translateY(0);
}

.artwork-card__title {
  font-family: var(--font-display);
  font-size: var(--text-body);
  color: #fff;
}

.artwork-card__subtitle {
  font-size: var(--text-small);
  color: rgba(255,255,255,0.6);
  margin-top: var(--space-xs);
}

/* Placeholder image */
.artwork-placeholder {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--surface);
  color: var(--fg-muted);
  font-family: var(--font-display);
  font-size: var(--text-small);
  text-align: center;
  padding: var(--space-md);
}

/* === Detail Overlay === */
.overlay {
  position: fixed;
  inset: 0;
  z-index: 200;
  background: var(--overlay-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  opacity: 0;
  pointer-events: none;
  visibility: hidden;
  transition: opacity var(--duration-normal) var(--ease-out),
              visibility var(--duration-normal) var(--ease-out);
  overflow-y: auto;
}

.overlay.active {
  opacity: 1;
  pointer-events: auto;
  visibility: visible;
}

.overlay__close {
  position: fixed;
  top: var(--space-lg);
  right: var(--space-lg);
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--surface);
  border-radius: var(--radius-full);
  font-size: 20px;
  z-index: 210;
  transition: background var(--duration-fast);
}

.overlay__close:hover {
  background: var(--surface-alt);
}

.overlay__content {
  max-width: min(1200px, 80vw);
  margin: 0 auto;
  padding: var(--space-5xl) var(--gutter) var(--space-3xl);
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.overlay__image {
  width: 100%;
  max-height: 70vh;
  margin-bottom: var(--space-2xl);
  border-radius: var(--radius-md);
  overflow: hidden;
  background: var(--bg);
  display: flex;
  justify-content: center;
  align-items: center;
}

.overlay__image img,
.overlay__image .artwork-placeholder {
  width: 100%;
  height: 100%;
  max-height: 70vh;
  object-fit: contain;
}

.overlay__title {
  font-family: var(--font-display);
  font-size: var(--text-h1);
  margin-bottom: var(--space-md);
}

.overlay__meta {
  width: 100%;
  display: flex;
  gap: var(--space-lg);
  margin-bottom: var(--space-xl);
  flex-wrap: wrap;
  border-bottom: 1px solid var(--border-subtle);
  padding-bottom: var(--space-md);
}

.overlay__meta-item {
  font-size: var(--text-small);
  color: var(--fg-secondary);
  font-family: var(--font-mono);
}

.overlay__meta-item strong {
  color: var(--fg);
  font-weight: 500;
}

.overlay__description {
  width: 100%;
  font-size: var(--text-body-lg);
  line-height: 1.7;
  color: var(--fg-secondary);
  max-width: 75ch;
}

/* === Buttons === */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: 10px 20px;
  border-radius: var(--radius-lg);
  font-size: var(--text-small);
  font-weight: 500;
  transition: all var(--duration-fast) var(--ease-out);
}

.btn--primary {
  background: var(--fg);
  color: var(--bg);
}

.btn--primary:hover {
  opacity: 0.85;
}

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

.btn--outline:hover {
  border-color: var(--fg-muted);
  background: var(--surface);
}

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

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

/* === Hero === */
.hero {
  position: relative;
  min-height: 80vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.hero__bg {
  position: absolute;
  inset: 0;
  background: var(--surface);
}

.hero__content {
  position: relative;
  z-index: 1;
  text-align: center;
  padding: var(--space-3xl) var(--gutter);
}

.hero__title {
  font-family: var(--font-display);
  font-size: var(--text-display);
  line-height: 1.05;
  margin-bottom: var(--space-lg);
}

.hero__subtitle {
  font-size: var(--text-body-lg);
  color: var(--fg-secondary);
  max-width: 50ch;
  margin: 0 auto var(--space-xl);
}

/* === Video player === */
.video-wrap {
  position: relative;
  width: 100%;
  aspect-ratio: 16/9;
  background: #000;
  border-radius: var(--radius-md);
  overflow: hidden;
}

.video-wrap video {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* === Footer === */
.footer {
  position: relative;
  z-index: 1;
  padding: var(--space-3xl) 0;
  border-top: 1px solid var(--border);
  margin-top: var(--space-4xl);
}

.footer__inner {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: var(--space-xl);
}

.footer__name {
  font-family: var(--font-display);
  font-size: var(--text-body);
}

.footer__social {
  display: flex;
  gap: var(--space-md);
}

.footer__social a {
  font-size: var(--text-small);
  color: var(--fg-muted);
  transition: color var(--duration-fast);
}

.footer__social a:hover {
  color: var(--fg);
}

/* === Section header === */
.section-header {
  margin-bottom: var(--space-2xl);
}

.section-header__label {
  font-family: var(--font-mono);
  font-size: var(--text-caption);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--accent);
  margin-bottom: var(--space-sm);
}

.section-header__title {
  font-family: var(--font-display);
  font-size: var(--text-h2);
}

/* === Bio === */
.bio-grid {
  display: grid;
  grid-template-columns: 1fr 1.5fr;
  gap: var(--space-3xl);
  align-items: start;
}

@media (max-width: 768px) {
  .bio-grid {
    grid-template-columns: 1fr;
  }
}

.bio__portrait {
  width: 100%;
  aspect-ratio: 3/4;
  background: var(--surface);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.bio__portrait img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.bio__text h2 {
  margin-bottom: var(--space-lg);
}

.bio__text p {
  margin-bottom: var(--space-md);
  color: var(--fg-secondary);
  line-height: 1.7;
}

/* === Exhibitions list === */
.exhibition-list {
  display: flex;
  flex-direction: column;
}

.exhibition-item {
  display: grid;
  grid-template-columns: 120px 1fr auto;
  gap: var(--space-lg);
  padding: var(--space-lg) 0;
  border-bottom: 1px solid var(--border);
  align-items: baseline;
}

@media (max-width: 768px) {
  .exhibition-item {
    grid-template-columns: 1fr;
    gap: var(--space-sm);
  }
}

.exhibition-item__year {
  font-family: var(--font-mono);
  font-size: var(--text-small);
  color: var(--fg-muted);
}

.exhibition-item__title {
  font-family: var(--font-display);
  font-size: var(--text-body);
}

.exhibition-item__venue {
  font-size: var(--text-small);
  color: var(--fg-secondary);
}

/* === Page header === */
.page-header {
  padding-top: calc(var(--nav-height) + var(--space-3xl));
  padding-bottom: var(--space-2xl);
}

.page-header__title {
  font-family: var(--font-display);
  font-size: var(--text-h1);
  margin-bottom: var(--space-md);
}

.page-header__subtitle {
  font-size: var(--text-body-lg);
  color: var(--fg-secondary);
  max-width: 60ch;
}

/* === Videos Section === */
.video-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
  margin-top: var(--space-xl);
}

@media (max-width: 900px) {
  .video-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-md);
  }
}

@media (max-width: 600px) {
  .video-grid {
    grid-template-columns: 1fr;
    gap: var(--space-md);
  }
}

.video-card {
  background: var(--surface);
  border: 1px solid var(--border-subtle);
  border-radius: 4px;
  overflow: hidden;
  transition: border-color var(--duration-fast) var(--ease-out),
              transform var(--duration-fast) var(--ease-out);
  cursor: pointer;
  display: flex;
  flex-direction: column;
}

.video-card:hover {
  border-color: var(--fg-dim);
  transform: translateY(-2px);
}

.video-card__poster-container {
  width: 100%;
  aspect-ratio: 16 / 9;
  background: var(--bg2);
  overflow: hidden;
  position: relative;
  border-bottom: 1px solid var(--border-subtle);
}

.video-card__poster {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--duration-slow) var(--ease-out);
  will-change: transform;
  backface-visibility: hidden;
}

.video-card:hover .video-card__poster {
  transform: scale(1.03);
}

.video-card__play-btn {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 56px;
  height: 56px;
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(4px);
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  transition: all var(--duration-normal) var(--ease-out);
  z-index: 2;
}

.video-card:hover .video-card__play-btn {
  background: var(--accent);
  color: #fff;
  border-color: transparent;
  transform: translate(-50%, -50%) scale(1.1);
  box-shadow: 0 0 15px rgba(220, 50, 50, 0.4);
}

.video-card__info {
  padding: var(--space-md);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  flex-grow: 1;
  background: var(--surface);
}

.video-card__meta {
  display: flex;
  flex-direction: column;
}

.video-card__title {
  margin: 0 0 4px 0;
  font-size: var(--text-body);
  font-weight: 600;
  color: var(--fg);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.video-card__subtitle {
  font-size: var(--text-small);
  color: var(--fg-secondary);
}

.overlay__video-container {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  background: #000;
  border: 1px solid var(--border-subtle);
  border-radius: 4px;
  overflow: hidden;
}

/* === Videos Page Slider & Mosaic === */

.video-slider__wrapper {
  position: relative;
  width: 100%;
  margin-bottom: var(--space-xl);
}

.video-slider {
  display: flex;
  gap: var(--space-md);
  overflow-x: auto;
  scroll-behavior: smooth;
  scrollbar-width: none; /* Firefox */
  -ms-overflow-style: none;  /* IE and Edge */
  padding: var(--space-sm) 2px;
  cursor: grab;
  user-select: none;
  -webkit-user-drag: none;
}

.video-slider::-webkit-scrollbar {
  display: none; /* Chrome, Safari and Opera */
}

.video-slider:active {
  cursor: grabbing;
}

.video-slider .video-card {
  flex: 0 0 340px; /* fixed size for slider items */
  max-width: 340px;
}

/* Navigation buttons for slider */
.video-slider__nav-btn {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--surface);
  border: 1px solid var(--border-subtle);
  color: var(--fg);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  z-index: 10;
  transition: all var(--duration-normal) var(--ease-out);
  box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

.video-slider__nav-btn:hover {
  background: var(--accent);
  color: #fff;
  border-color: transparent;
  box-shadow: 0 0 15px rgba(220, 50, 50, 0.4);
}

.video-slider__nav-btn--left {
  left: -22px;
}

.video-slider__nav-btn--right {
  right: -22px;
}

.video-mosaic {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-lg);
  margin-bottom: var(--space-2xl);
}

/* Modal Sequential Navigation buttons */
.overlay__nav-btn {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  width: 54px;
  height: 54px;
  border-radius: 50%;
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.15);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  z-index: 100;
  transition: all var(--duration-normal) var(--ease-out);
}

.overlay__nav-btn:hover {
  background: var(--accent);
  border-color: transparent;
  transform: translateY(-50%) scale(1.1);
  box-shadow: 0 0 15px rgba(220, 50, 50, 0.5);
  color: #fff;
}

.overlay__nav-btn--prev {
  left: 30px;
}

.overlay__nav-btn--next {
  right: 30px;
}

/* Responsive adjustments */
@media (max-width: 1200px) {
  .video-mosaic {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (max-width: 900px) {
  .video-mosaic {
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-md);
  }
  .overlay__nav-btn {
    width: 44px;
    height: 44px;
  }
  .overlay__nav-btn--prev {
    left: 15px;
  }
  .overlay__nav-btn--next {
    right: 15px;
  }
}

@media (max-width: 768px) {
  .video-slider__nav-btn {
    display: none; /* Hide buttons on mobile touch screens */
  }
  .video-slider .video-card {
    flex: 0 0 280px;
    max-width: 280px;
  }
}

@media (max-width: 600px) {
  .video-mosaic {
    grid-template-columns: 1fr;
  }
  .overlay__nav-btn {
    display: none; /* Hide buttons on very small screens to avoid cluttering */
  }
}