/* ============================================
   ZHEHAO SUN PORTFOLIO — Design System
   Dark Sci-Fi Aesthetic — Premium Animation Edition
   ============================================ */

/* ---------- Google Fonts ---------- */
@import url('https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@300;400;500;600;700&family=Playfair+Display:ital,wght@0,400;0,700;1,400&display=swap');

/* ---------- CSS Variables ---------- */
:root {
  /* Core palette */
  --bg-primary: #060b18;
  --bg-secondary: #0a1128;
  --bg-card: rgba(15, 22, 45, 0.75);
  --bg-card-hover: rgba(25, 35, 65, 0.85);

  /* Accent colors */
  --accent-gold: #c9a84c;
  --accent-gold-soft: rgba(201, 168, 76, 0.15);
  --accent-blue: #3a7bd5;
  --accent-cyan: #56c8d8;
  --accent-purple: #8b5cf6;

  /* Text */
  --text-primary: #e8e0d0;
  --text-secondary: rgba(232, 224, 208, 0.6);
  --text-muted: rgba(232, 224, 208, 0.35);

  /* Spacing */
  --section-padding: clamp(4rem, 10vh, 8rem) clamp(1.5rem, 5vw, 6rem);

  /* Typography */
  --font-sans: 'Space Grotesk', system-ui, sans-serif;
  --font-serif: 'Playfair Display', Georgia, serif;

  /* Transitions */
  --ease-out-expo: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-in-out: cubic-bezier(0.76, 0, 0.24, 1);
}

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

html {
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

html.lenis, html.lenis body {
  height: auto;
}

.lenis.lenis-smooth {
  scroll-behavior: auto !important;
}

.lenis.lenis-smooth [data-lenis-prevent] {
  overscroll-behavior: contain;
}

.lenis.lenis-stopped {
  overflow: hidden;
}

body {
  font-family: var(--font-sans);
  background: var(--bg-primary);
  color: var(--text-primary);
  overflow-x: hidden;
  line-height: 1.6;
  cursor: none;
}

::selection {
  background: var(--accent-gold);
  color: var(--bg-primary);
}

a {
  color: inherit;
  text-decoration: none;
  cursor: none;
}

button { cursor: none; }

img {
  display: block;
  max-width: 100%;
}
/* ---------- Three.js Canvas & Overlay ---------- */
#three-canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  pointer-events: none;
}


#bg-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 1;
  pointer-events: none;
  /* Very subtle vignette — most masking now happens in the shader */
  background: radial-gradient(
    ellipse at 50% 50%,
    transparent 0%,
    rgba(6, 11, 24, 0.15) 50%,
    rgba(6, 11, 24, 0.4) 100%
  );
}

/* ---------- Custom Cursor ---------- */
.cursor {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 9998;
  pointer-events: none;
  mix-blend-mode: difference;
}

.cursor-dot {
  position: absolute;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: #fff;
  transform: translate(-50%, -50%);
  transition: width 0.2s, height 0.2s;
}

.cursor-ring {
  position: absolute;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: 1px solid rgba(255, 255, 255, 0.5);
  transform: translate(-50%, -50%);
  transition: width 0.35s var(--ease-out-expo),
              height 0.35s var(--ease-out-expo),
              border-color 0.3s ease;
}

body:has(a:hover) .cursor-ring,
body:has(button:hover) .cursor-ring {
  width: 60px;
  height: 60px;
  border-color: var(--accent-gold);
}

body:has(a:hover) .cursor-dot,
body:has(button:hover) .cursor-dot {
  width: 10px;
  height: 10px;
  background: var(--accent-gold);
}

/* ---------- Text Reveal (Clip Animation) ---------- */
.text-reveal {
  display: inline-block;
  overflow: hidden;
  vertical-align: bottom;
}

.text-reveal-inner {
  display: inline-block;
  transform: translateY(110%);
  will-change: transform;
}

/* ---------- Parallax Data Attribute ---------- */
[data-speed] {
  will-change: transform;
}

/* ---------- Content Layer (above canvas + overlay) ---------- */
.content-layer {
  position: relative;
  z-index: 2;
}

/* ---------- Navigation ---------- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: 1.5rem clamp(1.5rem, 5vw, 4rem);
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: all 0.6s var(--ease-out-expo);
  transform: translateY(-100%);
  opacity: 0;
}

.nav.visible {
  transform: translateY(0);
  opacity: 1;
}

.nav.scrolled {
  background: rgba(6, 11, 24, 0.85);
  -webkit-backdrop-filter: blur(20px);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(201, 168, 76, 0.1);
}

.nav-logo {
  font-family: var(--font-sans);
  font-size: 1.1rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  color: var(--accent-gold);
  text-transform: uppercase;
  position: relative;
}

.nav-links {
  display: flex;
  gap: 2rem;
  list-style: none;
}

.nav-links a {
  font-size: 0.8rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-secondary);
  transition: color 0.3s ease;
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 1px;
  background: var(--accent-gold);
  transition: width 0.4s var(--ease-out-expo);
}

.nav-links a:hover {
  color: var(--accent-gold);
}

.nav-links a:hover::after {
  width: 100%;
}

/* Mobile menu */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: none;
  background: none;
  border: none;
  padding: 5px;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--accent-gold);
  transition: all 0.3s ease;
}

/* ---------- Section Base ---------- */
.section {
  min-height: 100vh;
  padding: var(--section-padding);
  display: flex;
  flex-direction: column;
  justify-content: center;
  position: relative;
}

/* ---------- Hero Section ---------- */
.hero {
  align-items: center;
  text-align: center;
  min-height: 100vh;
}

.hero-title {
  font-family: var(--font-serif);
  font-size: clamp(4rem, 12vw, 11rem);
  font-weight: 700;
  line-height: 0.95;
  letter-spacing: -0.03em;
  color: var(--text-primary);
}

.hero-title .text-reveal {
  display: block;
}

.hero-subtitle {
  font-size: clamp(0.9rem, 1.5vw, 1.2rem);
  letter-spacing: 0.3em;
  text-transform: uppercase;
  color: var(--accent-gold);
  margin-top: 2rem;
  font-weight: 300;
}

.hero-tagline {
  font-size: clamp(0.8rem, 1vw, 1rem);
  color: var(--text-muted);
  margin-top: 1rem;
  max-width: 500px;
}

.hero-tagline .text-reveal {
  display: block;
}

.scroll-indicator {
  position: absolute;
  bottom: 3rem;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  opacity: 0;
}

.scroll-indicator span {
  font-size: 0.65rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--text-muted);
}

.scroll-line {
  width: 1px;
  height: 40px;
  background: linear-gradient(to bottom, var(--accent-gold), transparent);
  animation: scrollPulse 2s ease-in-out infinite;
}

@keyframes scrollPulse {
  0%, 100% { opacity: 0.3; transform: scaleY(0.6); }
  50% { opacity: 1; transform: scaleY(1); }
}

/* ---------- About Section ---------- */
.about {
  max-width: 1200px;
  margin: 0 auto;
  width: 100%;
}

.about .section-title {
  margin-bottom: 2.25rem;
}

.section-label {
  font-size: 0.7rem;
  letter-spacing: 0.3em;
  text-transform: uppercase;
  color: var(--accent-gold);
  margin-bottom: 1rem;
  opacity: 0;
  transform: translateY(20px);
}

.section-title {
  font-family: var(--font-serif);
  font-size: clamp(2.5rem, 6vw, 5rem);
  font-weight: 700;
  margin-bottom: 3rem;
  line-height: 1.1;
}

.section-title .text-reveal {
  display: block;
}

.about-grid {
  display: grid;
  grid-template-columns: 280px 1fr 1fr;
  gap: 3rem;
  align-items: start;
}

/* Portrait */
.about-portrait {
  position: relative;
  opacity: 0;
  transform: translateY(30px);
}

.portrait-frame {
  position: relative;
  border-radius: 12px;
  overflow: hidden;
  aspect-ratio: 1 / 1.15;
  box-shadow:
    0 0 0 1px rgba(212, 175, 55, 0.15),
    0 20px 60px rgba(0, 0, 0, 0.5),
    0 0 40px rgba(212, 175, 55, 0.06);
  transition: transform 0.6s var(--ease-out-expo), box-shadow 0.6s var(--ease-out-expo);
}

.portrait-frame:hover {
  transform: translateY(-6px) scale(1.02);
  box-shadow:
    0 0 0 1px rgba(212, 175, 55, 0.3),
    0 30px 80px rgba(0, 0, 0, 0.6),
    0 0 60px rgba(212, 175, 55, 0.12);
}

.portrait-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 15%;
  filter: grayscale(30%) contrast(1.05);
  transition: filter 0.8s var(--ease-out-expo), transform 0.8s var(--ease-out-expo);
}

.portrait-frame:hover .portrait-img {
  filter: grayscale(0%) contrast(1.1);
  transform: scale(1.05);
}

.portrait-glow {
  position: absolute;
  inset: 0;
  background: linear-gradient(
    180deg,
    transparent 50%,
    rgba(212, 175, 55, 0.08) 100%
  );
  pointer-events: none;
}

.about-text {
  font-size: clamp(0.95rem, 1.2vw, 1.1rem);
  line-height: 1.8;
  color: var(--text-secondary);
}

.about-text p {
  margin-bottom: 1.5rem;
  opacity: 0;
  transform: translateY(30px);
}

.about-text .highlight {
  color: var(--accent-gold);
  font-weight: 500;
  position: relative;
  background-image: linear-gradient(var(--accent-gold), var(--accent-gold));
  background-repeat: no-repeat;
  background-position: left bottom;
  background-size: 0% 1px;
  padding-bottom: 1px;
  transition: background-size 0.8s var(--ease-out-expo);
}

/* Education Timeline */
.timeline {
  position: relative;
  padding-left: 2rem;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  height: 0%;
  width: 1px;
  background: linear-gradient(to bottom, var(--accent-gold), transparent);
  transition: height 1.5s var(--ease-out-expo);
}

.timeline.revealed::before {
  height: 100%;
}

.timeline-item {
  margin-bottom: 2rem;
  opacity: 0;
  transform: translateX(-20px);
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: -4px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--accent-gold);
  box-shadow: 0 0 12px rgba(201, 168, 76, 0.5);
  transform: scale(0);
  transition: transform 0.5s var(--ease-out-expo);
}

.timeline-item.revealed::before {
  transform: scale(1);
}

.timeline-date {
  font-size: 0.75rem;
  color: var(--accent-gold);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: 0.3rem;
}

.timeline-school {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 0.2rem;
}

.timeline-degree {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.timeline-location {
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* ---------- Works Section ---------- */
.works {
  max-width: 1400px;
  margin: 0 auto;
  width: 100%;
}

.works-header {
  overflow: hidden;
  padding: 2rem 0;
}

.works-marquee {
  font-family: var(--font-serif);
  font-size: clamp(3rem, 8vw, 7rem);
  font-weight: 700;
  white-space: nowrap;
  color: rgba(232, 224, 208, 0.06);
  letter-spacing: -0.02em;
  opacity: 0;
  -webkit-text-stroke: 1px rgba(201, 168, 76, 0.08);
}

.works-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2rem;
  margin-top: 3rem;
  perspective: 1200px;
}

/* Project Card */
.project-card {
  position: relative;
  border-radius: 12px;
  overflow: hidden;
  background: var(--bg-card);
  border: 1px solid rgba(201, 168, 76, 0.08);
  cursor: none;
  opacity: 0;
  transform: translateY(80px) scale(0.92) rotateX(4deg);
  transform-style: preserve-3d;
  will-change: transform, opacity;
  contain: layout style;
  transition: border-color 0.5s var(--ease-out-expo),
              background 0.5s ease,
              box-shadow 0.5s ease;
}

.project-card.revealed {
  opacity: 1;
  transform: translateY(0) scale(1);
}

.project-card:hover {
  border-color: rgba(201, 168, 76, 0.25);
  background: var(--bg-card-hover);
  box-shadow: 0 30px 80px rgba(0, 0, 0, 0.5),
              0 0 50px rgba(201, 168, 76, 0.06);
}

.project-card-image {
  width: 100%;
  aspect-ratio: 16 / 10;
  overflow: hidden;
  position: relative;
}

.project-card-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.8s var(--ease-out-expo);
  transform: scale(1.1);
}

.project-card.revealed .project-card-image img {
  transform: scale(1);
}

.project-card:hover .project-card-image img {
  transform: scale(1.06);
}

.project-card-image::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(to bottom, transparent 40%, rgba(6, 11, 24, 0.9));
  pointer-events: none;
}

/* Image Placeholder (blur filter for old images) */
.image-placeholder img {
  filter: blur(6px) saturate(0.4) brightness(0.6);
}

.image-placeholder .image-updating-label {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-size: 0.7rem;
  letter-spacing: 0.25em;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.7);
  background: rgba(6, 11, 24, 0.6);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
  padding: 0.6rem 1.4rem;
  border: 1px solid rgba(201, 168, 76, 0.3);
  border-radius: 4px;
  z-index: 5;
  pointer-events: none;
}

.project-card-content {
  padding: 1.5rem;
}

.project-card-category {
  font-size: 0.7rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--accent-gold);
  margin-bottom: 0.5rem;
}

.project-card-title {
  font-size: 1.3rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.project-card-desc {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.project-card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 1rem;
}

.tag {
  font-size: 0.7rem;
  padding: 0.3rem 0.7rem;
  border-radius: 20px;
  background: var(--accent-gold-soft);
  color: var(--accent-gold);
  letter-spacing: 0.05em;
  transform: translateY(10px);
  opacity: 0;
  transition: all 0.5s var(--ease-out-expo);
}

.project-card.revealed .tag {
  transform: translateY(0);
  opacity: 1;
}

/* For staggered tag reveals */
.project-card.revealed .tag:nth-child(1) { transition-delay: 0.1s; }
.project-card.revealed .tag:nth-child(2) { transition-delay: 0.15s; }
.project-card.revealed .tag:nth-child(3) { transition-delay: 0.2s; }

/* Project Detail Expansion */
.project-detail {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.6s var(--ease-out-expo), padding 0.4s ease;
  background: rgba(10, 17, 40, 0.5);
  border-top: 1px solid rgba(201, 168, 76, 0);
}

.project-detail.expanded {
  max-height: 600px;
  padding: 2rem 1.5rem;
  border-top-color: rgba(201, 168, 76, 0.15);
}

.project-detail-content {
  opacity: 0;
  transform: translateY(10px);
  transition: all 0.4s ease 0.2s;
}

.project-detail.expanded .project-detail-content {
  opacity: 1;
  transform: translateY(0);
}

.project-detail-text {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 1rem;
}

.project-detail-links {
  display: flex;
  gap: 1rem;
}

.project-link {
  font-size: 0.8rem;
  padding: 0.5rem 1.2rem;
  border: 1px solid var(--accent-gold);
  border-radius: 25px;
  color: var(--accent-gold);
  transition: all 0.3s ease;
}

.project-link:hover {
  background: var(--accent-gold);
  color: var(--bg-primary);
}

/* ---------- Research Section ---------- */
/* ---------- News (optional strip; hide on mobile by default) ---------- */
.news {
  max-width: 900px;
  margin: 0 auto;
  width: 100%;
}

.news .section-title {
  margin-bottom: 1.5rem;
}

.news-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

.news-item {
  display: grid;
  grid-template-columns: 4.5rem 1fr;
  gap: 1rem;
  align-items: baseline;
  padding: 0.35rem 0;
  border-bottom: 1px solid rgba(201, 168, 76, 0.08);
}

.news-year {
  font-family: var(--font-sans);
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  color: var(--accent-gold);
  font-weight: 600;
}

.news-text {
  font-size: 0.95rem;
  line-height: 1.55;
  color: rgba(255, 255, 255, 0.82);
}

.news-text em {
  font-style: italic;
  color: rgba(255, 255, 255, 0.92);
}


.research {
  max-width: 900px;
  margin: 0 auto;
  width: 100%;
}

.research-group {
  margin-top: 3.25rem;
}

.research-group:first-of-type {
  margin-top: 1.5rem;
}

.research-group .research-item {
  margin-bottom: 0.35rem;
}

.presenter-role {
  font-weight: 400;
  opacity: 0.72;
  letter-spacing: 0.02em;
}

.research-category-heading {
  font-family: var(--font-sans);
  font-size: 0.82rem;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent-gold);
  margin-bottom: 0.8rem;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid rgba(201, 168, 76, 0.15);
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.research-category-heading::before {
  content: '';
  display: inline-block;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent-gold);
}

.research-list {
  margin-top: 0.5rem;
}

.research-item {
  padding: 1.25rem 0 1.25rem 1.75rem;
  border-left: 1px solid rgba(201, 168, 76, 0.15);
  position: relative;
  opacity: 0;
  transform: translateX(-25px);
  margin-bottom: 0.6rem;
  transition: border-color 0.3s ease;
}

.research-item:hover {
  border-left-color: rgba(201, 168, 76, 0.4);
}

.research-item::before {
  content: '';
  position: absolute;
  left: -3px;
  top: 1.5rem;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--accent-gold);
  transform: scale(0);
  transition: transform 0.4s var(--ease-out-expo);
}

.research-item.revealed::before {
  transform: scale(1);
}

.research-type {
  font-size: 0.7rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--accent-cyan);
  margin-bottom: 0.5rem;
}

.research-title {
  font-size: 0.95rem;
  line-height: 1.6;
  color: var(--text-primary);
  margin-bottom: 0.35rem;
}

.research-title .author-highlight {
  color: var(--accent-gold);
  font-weight: 600;
}

.research-venue {
  font-size: 0.82rem;
  color: var(--text-secondary);
  font-style: italic;
  line-height: 1.5;
}

.pub-doi,
.pub-venue-link {
  margin-top: 0.4rem;
}

.pub-doi a,
.pub-venue-link a,
.research-link {
  display: inline;
  font-family: var(--font-sans);
  font-size: 0.82rem;
  font-weight: 400;
  letter-spacing: 0.02em;
  color: var(--text-secondary);
  text-decoration: none;
  border-bottom: 1px solid rgba(201, 168, 76, 0.28);
  transition: color 0.25s ease, border-color 0.25s ease;
  word-break: break-word;
}

.pub-doi a:hover,
.pub-venue-link a:hover,
.research-link:hover {
  color: var(--accent-gold);
  border-bottom-color: rgba(201, 168, 76, 0.7);
}

.pub-tags {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 0;
  margin-top: 0.45rem;
  font-family: var(--font-sans);
  font-size: 0.72rem;
  font-weight: 400;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
}

.pub-tag {
  padding: 0;
  border: none;
  border-radius: 0;
  background: none;
  color: inherit;
  font-weight: inherit;
  letter-spacing: inherit;
  text-transform: inherit;
}

.pub-tag + .pub-tag::before {
  content: '·';
  margin: 0 0.45rem;
  color: var(--text-muted);
  opacity: 0.8;
}

.pub-tag.journal,
.pub-tag.conf,
.pub-tag.chapter,
.pub-tag.inpress {
  background: none;
  border: none;
  color: var(--text-muted);
}

/* ---------- Contact Section ---------- */
.contact {
  max-width: 900px;
  margin: 0 auto;
  width: 100%;
  text-align: center;
}

.social-links {
  display: flex;
  justify-content: center;
  gap: 1.5rem;
  margin-top: 2rem;
  margin-bottom: 1.25rem;
  opacity: 0;
}

.contact-email {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 0.95rem;
  letter-spacing: 0.02em;
  color: var(--text-secondary);
  opacity: 0;
}

.contact-email a {
  color: var(--text-secondary);
  text-decoration: none;
  border-bottom: 1px solid rgba(201, 168, 76, 0.35);
  transition: color 0.3s ease, border-color 0.3s ease;
}

.contact-email a:hover {
  color: var(--accent-gold);
  border-bottom-color: var(--accent-gold);
}

.social-link {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  border: 1px solid rgba(201, 168, 76, 0.2);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.4s var(--ease-out-expo);
  color: var(--text-secondary);
}

.social-link:hover {
  border-color: var(--accent-gold);
  background: var(--accent-gold-soft);
  color: var(--accent-gold);
  transform: translateY(-5px) scale(1.1);
  box-shadow: 0 15px 30px rgba(201, 168, 76, 0.15);
}

.social-link svg {
  width: 20px;
  height: 20px;
  fill: currentColor;
}



/* ---------- Touch Ripple ---------- */
.touch-ripple {
  position: relative;
  overflow: hidden;
  -webkit-tap-highlight-color: transparent;
}

.touch-ripple .ripple-effect {
  position: absolute;
  border-radius: 50%;
  background: rgba(201, 168, 76, 0.25);
  transform: scale(0);
  animation: rippleAnim 0.6s ease-out forwards;
  pointer-events: none;
}

@keyframes rippleAnim {
  to {
    transform: scale(4);
    opacity: 0;
  }
}

/* ---------- Footer ---------- */
.footer {
  text-align: center;
  padding: 2rem;
  font-size: 0.75rem;
  color: var(--text-muted);
  letter-spacing: 0.05em;
}

/* ---------- Loading Screen ---------- */
.loader {
  position: fixed;
  inset: 0;
  background: var(--bg-primary);
  z-index: 9999;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  gap: 1.5rem;
  transition: opacity 0.8s var(--ease-out-expo),
              visibility 0.8s var(--ease-out-expo);
}

.loader.loaded {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
}

.loader-counter {
  font-family: var(--font-sans);
  font-size: 4rem;
  font-weight: 300;
  color: var(--accent-gold);
  letter-spacing: 0.05em;
}

.loader-ring {
  width: 40px;
  height: 40px;
  border: 2px solid rgba(201, 168, 76, 0.15);
  border-top-color: var(--accent-gold);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.loader-text {
  font-size: 0.7rem;
  letter-spacing: 0.3em;
  text-transform: uppercase;
  color: var(--text-muted);
}

/* ---------- Scroll Progress ---------- */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 2px;
  width: 100%;
  transform: scaleX(0);
  transform-origin: left;
  background: linear-gradient(90deg, var(--accent-gold), var(--accent-cyan));
  z-index: 101;
  transition: transform 0.1s linear;
}

/* ---------- Ambient Glow Lines ---------- */
.section::before {
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 1px;
  height: 120px;
  background: linear-gradient(to bottom, rgba(201, 168, 76, 0.4), transparent);
  opacity: 0;
  transition: opacity 1s ease;
}

.section.in-view::before {
  opacity: 1;
}

/* ---------- Responsive ---------- */
@media (max-width: 768px) {
  body { cursor: auto; }
  a, button { cursor: auto; }
  .cursor { display: none; }

  /* --- Mobile Nav Toggle (animated hamburger → X) --- */
  .nav-links {
    display: flex;
    flex-direction: column;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(6, 11, 24, 0.97);
    -webkit-backdrop-filter: blur(20px);
    backdrop-filter: blur(20px);
    justify-content: center;
    align-items: center;
    gap: 0;
    z-index: 99;
    pointer-events: none;
    opacity: 0;
    transition: opacity 0.4s ease;
  }

  .nav-links.open {
    pointer-events: auto;
    opacity: 1;
  }

  .nav-links li {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.4s ease, transform 0.4s var(--ease-out-expo);
  }

  .nav-links.open li {
    opacity: 1;
    transform: translateY(0);
  }

  /* Staggered entrance */
  .nav-links.open li:nth-child(1) { transition-delay: 0.08s; }
  .nav-links.open li:nth-child(2) { transition-delay: 0.16s; }
  .nav-links.open li:nth-child(3) { transition-delay: 0.24s; }
  .nav-links.open li:nth-child(4) { transition-delay: 0.32s; }

  .nav-links a {
    font-size: 1.4rem;
    padding: 1rem 2rem;
    display: block;
  }

  .nav-toggle {
    display: flex;
    cursor: auto;
    z-index: 101;
    position: relative;
    width: 44px;
    height: 44px;
    align-items: center;
    justify-content: center;
  }

  /* Hamburger → X animation */
  .nav-toggle span {
    position: absolute;
    transition: all 0.35s var(--ease-out-expo);
    transform-origin: center;
  }

  .nav-toggle span:nth-child(1) { transform: translateY(-7px); }
  .nav-toggle span:nth-child(3) { transform: translateY(7px); }

  .nav-toggle.active span:nth-child(1) {
    transform: rotate(45deg);
  }
  .nav-toggle.active span:nth-child(2) {
    opacity: 0;
    transform: scaleX(0);
  }
  .nav-toggle.active span:nth-child(3) {
    transform: rotate(-45deg);
  }

  /* --- Layout --- */
  .news--hide-mobile {
    display: none !important;
  }

  .about-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .about-portrait {
    max-width: 240px;
    margin: 0 auto;
  }

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

  /* --- Touch Targets (min 44px per WCAG) --- */
  .social-links {
    gap: 0.8rem;
    flex-wrap: wrap;
  }

  .social-link {
    width: 52px;
    height: 52px;
  }

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

  .research-link,
  .pub-doi a,
  .pub-venue-link a {
    font-size: 0.85rem;
    padding: 0.15rem 0;
    display: inline;
    min-height: 0;
    line-height: 1.7;
  }

  .research-item {
    padding: 1.2rem 0 1.2rem 1.2rem;
  }

  .project-card-header {
    min-height: 44px;
  }

  /* --- Typography scaling --- */
  .hero-title {
    font-size: clamp(3rem, 14vw, 5rem);
  }

  .section-title {
    font-size: clamp(2rem, 8vw, 3rem);
  }

  .section {
    padding: clamp(3rem, 8vh, 5rem) clamp(1.2rem, 4vw, 2rem);
  }

  /* --- Reduce heavy effects --- */
  .portrait-frame:hover {
    transform: none;
  }

  /* Disable parallax jank on mobile */
  [data-speed] {
    will-change: auto;
  }
}

/* ---------- Utility ---------- */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
  border: 0;
}



/* System cursor when custom cursor is skipped (weak desktop / reduced-motion) */
html.system-cursor,
html.system-cursor body,
html.system-cursor a,
html.system-cursor button {
  cursor: auto !important;
}
html.system-cursor .cursor {
  display: none !important;
}
/* ---------- Prefers Reduced Motion ---------- */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }

  .cursor {
    display: none !important;
  }

  .text-reveal-inner {
    transform: none !important;
    opacity: 1 !important;
  }

  .section-label,
  .scroll-indicator,
  .portrait-frame,
  .research-item,
  .about-portrait,
  .timeline-item,
  .news-item,
  .project-card,
  .social-links,
  .contact-email {
    opacity: 1 !important;
    transform: none !important;
  }

  .scroll-line {
    animation: none !important;
  }

  .loader {
    display: none !important;
  }
}