/* ============================================================
   褚杰个人网站 — Style Sheet
   黑白高级风 / Black & White Premium
   ============================================================ */

/* --- CSS Variables / 修改这里可快速更换主题 --- */
:root {
  --black: #000000;
  --white: #ffffff;
  --gray-100: #f5f5f5;
  --gray-200: #e8e8e8;
  --gray-300: #d0d0d0;
  --gray-400: #a0a0a0;
  --gray-500: #707070;
  --gray-600: #404040;
  --gray-700: #2a2a2a;
  --gray-800: #1a1a1a;
  --gray-900: #0d0d0d;

  --font-heading: 'Playfair Display', 'Noto Serif SC', 'STSong', Georgia, serif;
  --font-body: 'Inter', 'PingFang SC', 'Microsoft YaHei', -apple-system, sans-serif;

  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 2rem;
  --space-lg: 4rem;
  --space-xl: 6rem;
  --space-2xl: 10rem;

  --transition-fast: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-smooth: 0.6s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-slow: 1s cubic-bezier(0.16, 1, 0.3, 1);
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-body);
  background: var(--white);
  color: var(--black);
  line-height: 1.6;
  overflow-x: hidden;
}

body.loading {
  overflow: hidden;
}

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

button {
  background: none;
  border: none;
  cursor: pointer;
  font-family: inherit;
  color: inherit;
}

ul { list-style: none; }
img { max-width: 100%; display: block; }

/* --- Container --- */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-md);
}

/* ============================================================
   WELCOME PAGE (Preloader)
   ============================================================ */
#preloader {
  position: fixed;
  inset: 0;
  z-index: 9999;
  background: var(--black);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: opacity 1.2s cubic-bezier(0.16, 1, 0.3, 1),
              visibility 1.2s cubic-bezier(0.16, 1, 0.3, 1);
}

#preloader.hidden {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
}

/* Welcome content container */
.welcome-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0;
}

/* JC Letters */
.welcome-letters {
  display: flex;
  gap: 0.6em;
  margin-bottom: 2rem;
}

.letter {
  font-family: var(--font-heading);
  font-size: clamp(4rem, 10vw, 7rem);
  font-weight: 300;
  color: var(--white);
  letter-spacing: 0.1em;
  opacity: 0;
  transform: translateY(30px);
  animation: letterReveal 1s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

.letter-j {
  animation-delay: 0.3s;
}

.letter-c {
  animation-delay: 0.6s;
}

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

/* Welcome divider line */
.welcome-divider {
  width: 40px;
  height: 1px;
  background: var(--gray-500);
  margin-bottom: 1.5rem;
  opacity: 0;
  animation: fadeIn 0.8s ease forwards 1s;
}

/* Name */
.welcome-name {
  font-family: var(--font-heading);
  font-size: clamp(1.2rem, 2.5vw, 1.6rem);
  font-weight: 400;
  color: var(--white);
  letter-spacing: 0.15em;
  margin-bottom: 0.8rem;
  opacity: 0;
  transform: translateY(15px);
  animation: fadeIn 0.8s ease forwards 1.2s;
}

/* Tagline */
.welcome-tagline {
  font-family: var(--font-body);
  font-size: clamp(0.8rem, 1.5vw, 0.95rem);
  font-weight: 300;
  color: var(--gray-400);
  letter-spacing: 0.08em;
  margin-bottom: 2.5rem;
  opacity: 0;
  animation: fadeIn 0.8s ease forwards 1.5s;
}

/* AI hint */
.welcome-ai {
  font-size: 0.7rem;
  font-weight: 300;
  color: var(--gray-600);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  opacity: 0;
  animation: fadeIn 0.8s ease forwards 1.8s;
}

/* Click to enter prompt */
.welcome-enter {
  position: absolute;
  bottom: 3rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.8rem;
  opacity: 0;
  animation: fadeIn 0.8s ease forwards 2.2s;
}

.enter-text {
  font-size: 0.7rem;
  font-weight: 400;
  color: var(--gray-500);
  letter-spacing: 0.2em;
  text-transform: uppercase;
  transition: color 0.3s ease;
}

#preloader:hover .enter-text {
  color: var(--white);
}

.enter-line {
  width: 1px;
  height: 30px;
  background: var(--gray-600);
  position: relative;
  overflow: hidden;
}

.enter-line::after {
  content: '';
  position: absolute;
  top: -100%;
  left: 0;
  width: 100%;
  height: 100%;
  background: var(--white);
  animation: enterLinePulse 2s ease-in-out infinite;
}

@keyframes enterLinePulse {
  0% { top: -100%; }
  50% { top: 100%; }
  100% { top: 100%; }
}

/* Hero photo — desktop: clean presentation, no masking */
.hero-photo {
  width: 100%;
  max-width: 380px;
  aspect-ratio: 3 / 4;
  object-fit: cover;
  object-position: center top;
  border-radius: 2px;
}

/* Hero mobile photo — hidden on desktop */
.hero-mobile-photo {
  display: none;
}

/* Mobile adjustments for welcome page */
@media (max-width: 768px) {
  .welcome-enter {
    bottom: 2rem;
  }
}

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

/* ============================================================
   NAVIGATION
   ============================================================ */
#navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.5rem var(--space-md);
  transition: all var(--transition-fast);
}

#navbar.scrolled {
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--gray-200);
  padding: 1rem var(--space-md);
}

/* On dark hero section, make nav white */
#navbar.on-dark {
  color: var(--white);
}
#navbar.on-dark.scrolled {
  color: var(--black);
}

.nav-logo {
  font-family: var(--font-heading);
  font-size: 1.5rem;
  font-weight: 400;
  letter-spacing: 0.1em;
  transition: opacity var(--transition-fast);
}
.nav-logo:hover { opacity: 0.6; }

.nav-links {
  display: flex;
  gap: 2.5rem;
}

.nav-links a {
  font-size: 0.85rem;
  font-weight: 400;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  position: relative;
  transition: opacity var(--transition-fast);
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 1px;
  background: currentColor;
  transition: width var(--transition-fast);
}

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

/* Language toggle - positioned at body level */
#lang-toggle {
  position: fixed;
  top: 1.5rem;
  right: var(--space-md);
  z-index: 1001;
  font-size: 0.8rem;
  font-weight: 500;
  letter-spacing: 0.05em;
  padding: 0.4rem 0.8rem;
  border: 1px solid var(--gray-400);
  border-radius: 2px;
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  transition: all var(--transition-fast);
}

/* When navbar is on dark hero section */
body.dark-nav #lang-toggle {
  border-color: var(--gray-600);
  background: rgba(0, 0, 0, 0.5);
  color: var(--white);
}

#lang-toggle:hover {
  background: var(--black);
  color: var(--white);
  border-color: var(--black);
}
body.dark-nav #lang-toggle:hover {
  background: var(--white);
  color: var(--black);
  border-color: var(--white);
}

/* Hamburger */
#menu-toggle {
  display: none;
  flex-direction: column;
  gap: 6px;
  width: 28px;
  padding: 4px 0;
}

#menu-toggle span {
  display: block;
  height: 1.5px;
  background: currentColor;
  transition: all var(--transition-fast);
  transform-origin: center;
}

#menu-toggle.active span:first-child {
  transform: rotate(45deg) translate(3px, 3px);
}
#menu-toggle.active span:last-child {
  transform: rotate(-45deg) translate(4px, -4px);
}

/* ============================================================
   HERO SECTION
   ============================================================ */
#hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  background: var(--black);
  color: var(--white);
  padding: var(--space-2xl) var(--space-md) var(--space-lg);
  position: relative;
}

.hero-content {
  max-width: 1200px;
  margin: 0 auto;
  width: 100%;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-lg);
  align-items: center;
  flex: 1;
}

.hero-name {
  font-family: var(--font-heading);
  font-weight: 400;
  line-height: 1.1;
  margin-bottom: var(--space-md);
}

.hero-name-zh {
  display: block;
  font-size: clamp(3.5rem, 8vw, 7rem);
  letter-spacing: 0.05em;
  opacity: 0;
  transform: translateY(40px);
  animation: heroReveal 1s ease forwards 0.5s;
}

.hero-name-en {
  display: block;
  font-size: clamp(1.2rem, 2.5vw, 1.8rem);
  font-weight: 300;
  font-style: italic;
  letter-spacing: 0.15em;
  color: var(--gray-400);
  margin-top: 0.5rem;
  opacity: 0;
  transform: translateY(30px);
  animation: heroReveal 1s ease forwards 0.8s;
}

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

.hero-divider {
  width: 60px;
  height: 1px;
  background: var(--gray-500);
  margin-bottom: var(--space-md);
  opacity: 0;
  animation: heroReveal 1s ease forwards 1s;
}

.hero-tagline {
  font-family: var(--font-heading);
  font-size: clamp(1.1rem, 2vw, 1.5rem);
  font-weight: 400;
  letter-spacing: 0.02em;
  margin-bottom: var(--space-sm);
  opacity: 0;
  transform: translateY(20px);
  animation: heroReveal 1s ease forwards 1.2s;
}

.hero-desc {
  font-size: 0.9rem;
  color: var(--gray-400);
  letter-spacing: 0.03em;
  opacity: 0;
  transform: translateY(20px);
  animation: heroReveal 1s ease forwards 1.4s;
}

/* Hero visual / photo placeholder */
.hero-visual {
  display: flex;
  justify-content: center;
  align-items: center;
  opacity: 0;
  animation: heroReveal 1.2s ease forwards 1s;
}

.hero-frame,
.photo-frame,
.project-image {
  aspect-ratio: 3 / 4;
  border: 1px solid var(--gray-600);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
  transition: border-color var(--transition-fast);
}

.hero-frame {
  width: 100%;
  max-width: 380px;
  background: var(--gray-900);
}

.hero-frame:hover,
.photo-frame:hover {
  border-color: var(--gray-400);
}

.frame-label {
  font-size: 0.75rem;
  color: var(--gray-500);
  letter-spacing: 0.15em;
  text-transform: uppercase;
}

/* Scroll indicator */
.scroll-indicator {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  margin-top: var(--space-lg);
  opacity: 0;
  animation: heroReveal 1s ease forwards 1.8s;
}

.scroll-indicator span {
  font-size: 0.7rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--gray-500);
}

.scroll-line {
  width: 40px;
  height: 1px;
  background: var(--gray-600);
  position: relative;
  overflow: hidden;
}

.scroll-line::after {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: var(--white);
  animation: scrollLineMove 2s ease-in-out infinite;
}

@keyframes scrollLineMove {
  0% { left: -100%; }
  50% { left: 100%; }
  100% { left: 100%; }
}

/* ============================================================
   SECTION COMMON
   ============================================================ */
section {
  padding: var(--space-2xl) 0;
}

.section-title {
  font-family: var(--font-heading);
  font-size: clamp(2rem, 4vw, 3.5rem);
  font-weight: 400;
  letter-spacing: 0.02em;
  margin-bottom: var(--space-lg);
  position: relative;
  display: inline-block;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: -12px;
  left: 0;
  width: 40px;
  height: 2px;
  background: var(--black);
}

.section-subtitle {
  font-size: 1rem;
  color: var(--gray-500);
  margin-top: calc(-1 * var(--space-md));
  margin-bottom: var(--space-lg);
  letter-spacing: 0.02em;
}

/* Scroll reveal */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity var(--transition-slow), transform var(--transition-slow);
}

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

/* ============================================================
   ABOUT SECTION
   ============================================================ */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: var(--space-lg);
  margin-bottom: var(--space-lg);
  align-items: start;
}

.about-intro p {
  font-size: 1.1rem;
  line-height: 1.9;
  color: var(--gray-700);
  max-width: 640px;
}

.photo-frame {
  width: 100%;
  background: var(--gray-100);
}

/* ============================================================
   EXPANDABLE CARDS
   ============================================================ */
.expand-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 1px;
  background: var(--gray-200);
  border: 1px solid var(--gray-200);
}

.expand-card {
  background: var(--white);
}

.expand-header {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-md);
  font-size: 1rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  text-align: left;
  transition: background var(--transition-fast);
}

.expand-header:hover {
  background: var(--gray-100);
}

.expand-icon {
  font-size: 1.4rem;
  font-weight: 300;
  transition: transform var(--transition-fast);
  flex-shrink: 0;
  width: 24px;
  text-align: center;
}

.expand-card.open .expand-icon,
.timeline-content.open .expand-icon {
  transform: rotate(45deg);
}

.expand-body {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-smooth), padding var(--transition-smooth);
  padding: 0 var(--space-md);
}

.expand-card.open .expand-body,
.timeline-content.open .expand-body {
  padding: 0 var(--space-md) var(--space-md);
}

.expand-body p {
  font-size: 0.95rem;
  line-height: 1.8;
  color: var(--gray-600);
}

.placeholder-text {
  font-style: italic;
  color: var(--gray-400) !important;
}

/* ============================================================
   PORTFOLIO SECTION
   ============================================================ */
.portfolio-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2px;
}

.project-card {
  cursor: pointer;
  position: relative;
  overflow: hidden;
}

.project-image {
  aspect-ratio: 4 / 3;
  background: var(--gray-100);
  border: none;
  transition: all var(--transition-smooth);
}

.project-image .frame-label {
  transition: opacity var(--transition-fast);
}

.project-card:hover .project-image {
  background: var(--gray-200);
}

.project-info {
  padding: var(--space-sm) var(--space-md);
  transition: background var(--transition-fast);
}

.project-card:hover .project-info {
  background: var(--gray-100);
}

.project-info h3 {
  font-family: var(--font-heading);
  font-size: 1.1rem;
  font-weight: 500;
  margin-bottom: 0.25rem;
}

.project-info p {
  font-size: 0.8rem;
  color: var(--gray-500);
  letter-spacing: 0.03em;
}

/* ============================================================
   RESUME / TIMELINE
   ============================================================ */
.resume-actions {
  margin-bottom: var(--space-lg);
}

.btn-download {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.8rem 1.6rem;
  border: 1px solid var(--black);
  font-size: 0.85rem;
  font-weight: 500;
  letter-spacing: 0.05em;
  transition: all var(--transition-fast);
}

.btn-download:hover {
  background: var(--black);
  color: var(--white);
}

.btn-download svg {
  transition: transform var(--transition-fast);
}
.btn-download:hover svg {
  transform: translateY(2px);
}

/* Timeline */
.timeline {
  position: relative;
  padding-left: var(--space-lg);
}

.timeline::before {
  content: '';
  position: absolute;
  left: 8px;
  top: 0;
  bottom: 0;
  width: 1px;
  background: var(--gray-300);
}

.timeline-item {
  position: relative;
  margin-bottom: var(--space-md);
}

.timeline-marker {
  position: absolute;
  left: calc(-1 * var(--space-lg) + 4px);
  top: 1.6rem;
  width: 9px;
  height: 9px;
  border: 2px solid var(--black);
  border-radius: 50%;
  background: var(--white);
  z-index: 1;
  transition: all var(--transition-fast);
}

.timeline-marker.edu {
  border-color: var(--gray-500);
}

.timeline-item:hover .timeline-marker {
  background: var(--black);
}

.timeline-content {
  border-bottom: 1px solid var(--gray-200);
}

.timeline-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: var(--space-md);
}

.timeline-header h3 {
  font-family: var(--font-heading);
  font-size: 1.2rem;
  font-weight: 500;
}

.role {
  font-size: 0.9rem;
  color: var(--gray-500);
  margin-top: 0.25rem;
}

.year {
  font-size: 0.85rem;
  color: var(--gray-400);
  letter-spacing: 0.05em;
  white-space: nowrap;
  font-variant-numeric: tabular-nums;
}

.achievements {
  margin-top: var(--space-sm);
  padding-left: 1rem;
}

.achievements li {
  position: relative;
  padding-left: 1rem;
  margin-bottom: 0.5rem;
  font-size: 0.9rem;
  color: var(--gray-600);
  line-height: 1.6;
}

.achievements li::before {
  content: '—';
  position: absolute;
  left: 0;
  color: var(--gray-400);
}

/* Education items */
.edu-item {
  margin-bottom: var(--space-sm);
  padding-bottom: var(--space-sm);
  border-bottom: 1px solid var(--gray-100);
}
.edu_item:last-child {
  border-bottom: none;
}

.school {
  font-weight: 500;
  font-size: 1rem;
}

.degree {
  font-size: 0.9rem;
  color: var(--gray-500);
  margin: 0.2rem 0;
}

.edu-item .year {
  font-size: 0.8rem;
}

/* ============================================================
   PERSONAL SECTION
   ============================================================ */
#personal {
  background: var(--gray-100);
}

#personal .section-title::after {
  background: var(--black);
}

/* ============================================================
   CONTACT SECTION
   ============================================================ */
#contact {
  background: var(--black);
  color: var(--white);
  text-align: center;
  padding: var(--space-2xl) 0;
}

.contact-heading {
  font-family: var(--font-heading);
  font-size: clamp(2.5rem, 5vw, 4rem);
  font-weight: 400;
  letter-spacing: 0.02em;
  margin-bottom: var(--space-lg);
}

.contact-links {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
  max-width: 400px;
  margin: 0 auto;
}

.contact-link {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--space-sm) 0;
  border-bottom: 1px solid var(--gray-700);
  transition: border-color var(--transition-fast);
}

.contact-link:hover {
  border-color: var(--gray-400);
}

.contact-label {
  font-size: 0.75rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--gray-500);
}

.contact-value {
  font-size: 0.95rem;
  transition: color var(--transition-fast);
}

.contact-link:hover .contact-value {
  color: var(--gray-300);
}

/* ============================================================
   FOOTER
   ============================================================ */
footer {
  background: var(--black);
  color: var(--gray-600);
  text-align: center;
  padding: var(--space-md);
  font-size: 0.75rem;
  letter-spacing: 0.05em;
  border-top: 1px solid var(--gray-800);
}

/* ============================================================
   PROJECT MODAL
   ============================================================ */
.modal {
  position: fixed;
  inset: 0;
  z-index: 2000;
  background: rgba(0, 0, 0, 0.85);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-fast);
}

.modal.active {
  opacity: 1;
  visibility: visible;
}

.modal-close {
  position: absolute;
  top: 2rem;
  right: 2rem;
  font-size: 2rem;
  color: var(--white);
  z-index: 10;
  transition: opacity var(--transition-fast);
}
.modal-close:hover { opacity: 0.6; }

.modal-content {
  background: var(--white);
  max-width: 800px;
  width: 90%;
  max-height: 85vh;
  overflow-y: auto;
  transform: translateY(20px);
  transition: transform var(--transition-smooth);
}

.modal.active .modal-content {
  transform: translateY(0);
}

.modal-image {
  aspect-ratio: 16 / 9;
  background: var(--gray-100);
  display: flex;
  align-items: center;
  justify-content: center;
}

.modal-body {
  padding: var(--space-md);
}

.modal-title {
  font-family: var(--font-heading);
  font-size: 1.5rem;
  font-weight: 500;
  margin-bottom: 0.5rem;
}

.modal-subtitle {
  font-size: 0.85rem;
  color: var(--gray-500);
  margin-bottom: var(--space-sm);
}

.modal-desc p {
  font-size: 0.95rem;
  line-height: 1.8;
  color: var(--gray-600);
}

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 1024px) {
  .portfolio-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  :root {
    --space-2xl: 6rem;
    --space-lg: 3rem;
  }

  /* Mobile nav */
  .nav-links {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--white);
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 2rem;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-fast);
    z-index: 999;
  }

  .nav-links.open {
    opacity: 1;
    visibility: visible;
  }

  .nav-links a {
    font-size: 1.2rem;
    color: var(--black);
  }

  #menu-toggle {
    display: flex;
    z-index: 1001;
  }

  #lang-toggle {
    top: auto;
    bottom: 1.5rem;
    right: 1.5rem;
    background: rgba(255, 255, 255, 0.95);
    border-color: var(--gray-300);
    color: var(--black);
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.1);
  }

  /* Hero mobile */
  .hero-content {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-visual { display: none; }

  /* Mobile hero photo — frosted glass at bottom */
  .hero-mobile-photo {
    display: block;
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    width: 100%;
    height: 65vh;
    object-fit: cover;
    object-position: center top;
    opacity: 0.55;
    -webkit-mask-image: linear-gradient(to top, rgba(0,0,0,1) 0%, rgba(0,0,0,0.4) 50%, transparent 100%);
    mask-image: linear-gradient(to top, rgba(0,0,0,1) 0%, rgba(0,0,0,0.4) 50%, transparent 100%);
    pointer-events: none;
  }

  /* Frosted glass overlay */
  #hero::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 65vh;
    background: linear-gradient(to top, var(--black) 0%, rgba(0,0,0,0.15) 70%, transparent 100%);
    pointer-events: none;
    z-index: 0;
  }

  #hero .hero-content,
  #hero .scroll-indicator {
    position: relative;
    z-index: 1;
  }

  .hero-divider {
    margin-left: auto;
    margin-right: auto;
  }

  .scroll-indicator {
    justify-content: center;
  }

  /* About mobile */
  .about-grid {
    grid-template-columns: 1fr;
  }

  .about-photo { display: none; }

  /* Portfolio mobile */
  .portfolio-grid {
    grid-template-columns: 1fr;
  }

  /* Expand grid mobile */
  .expand-grid {
    grid-template-columns: 1fr;
  }

  /* Timeline mobile */
  .timeline {
    padding-left: var(--space-md);
  }

  .timeline-header {
    flex-direction: column;
    gap: 0.25rem;
  }

  .section-title::after {
    display: none;
  }
}

/* ============================================================
   UTILITY / ANIMATION HELPERS
   ============================================================ */
.stagger-1 { transition-delay: 0.1s; }
.stagger-2 { transition-delay: 0.2s; }
.stagger-3 { transition-delay: 0.3s; }
.stagger-4 { transition-delay: 0.4s; }
.stagger-5 { transition-delay: 0.5s; }
.stagger-6 { transition-delay: 0.6s; }

/* Smooth cursor-following hover for project cards */
@media (hover: hover) {
  .project-card::after {
    content: '';
    position: absolute;
    inset: 0;
    background: radial-gradient(
      600px circle at var(--mouse-x, 50%) var(--mouse-y, 50%),
      rgba(0, 0, 0, 0.06),
      transparent 40%
    );
    opacity: 0;
    transition: opacity var(--transition-fast);
    pointer-events: none;
    z-index: 1;
  }

  .project-card:hover::after {
    opacity: 1;
  }
}