/* ================================================
   RUNQI ZOU — PORTFOLIO
   assets/css/style.css
   ================================================
   1.  Custom Properties
   2.  Reset & Base
   3.  Site Layout (sidebar + content)
   4.  Sidebar
   5.  Side Navigation (line indicators)
   6.  Mobile Navigation
   7.  Content Sections
   8.  Intro Section
   9.  Work Section (projects grid + filter)
   10. Project Cards
   11. Research Section
   12. Awards Section
   13. Playground Section
   14. Contact Section
   15. Footer
   16. Reveal Animations
   17. Buttons & Tags
   18. Project Detail Pages
   19. Responsive — Tablet (≤900px)
   20. Responsive — Mobile (≤700px)
   21. Print
   ================================================ */


/* ── 1. Custom Properties ─────────────────────── */
:root {
  --bg: #FAFAF8;
  --bg-alt: #F2F2EF;
  --bg-card: #FFFFFF;
  --text: #0F0F0E;
  --text-sec: #6A6A68;
  --text-muted: #A0A09E;
  --accent: #2563EB;
  --border: #E5E5E2;
  --border-light: #EEEEEB;

  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

  /* Type Scale */
  --t-xs: 0.6875rem;
  --t-sm: 0.8125rem;
  --t-base: 1rem;
  --t-lg: 1.125rem;
  --t-xl: 1.375rem;
  --t-2xl: 1.75rem;
  --t-3xl: 2.25rem;
  --t-4xl: 3rem;

  /* Spacing */
  --s2: 0.5rem;
  --s3: 0.75rem;
  --s4: 1rem;
  --s6: 1.5rem;
  --s8: 2rem;
  --s10: 2.5rem;
  --s12: 3rem;
  --s16: 4rem;
  --s20: 5rem;
  --s24: 6rem;

  /* Layout */
  --sidebar-w: 300px;
  --nav-h: 60px;
  /* mobile only */
  --radius: 6px;
  --radius-lg: 10px;

  /* Effects */
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.07), 0 4px 12px rgba(0, 0, 0, 0.04);
  --shadow-hover: 0 4px 20px rgba(0, 0, 0, 0.11), 0 8px 32px rgba(0, 0, 0, 0.05);
  --ease: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  --ease-spring: 0.55s cubic-bezier(0.16, 1, 0.3, 1);
}


/* ── 2. Reset & Base ─────────────────────────── */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font);
  font-size: var(--t-base);
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

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

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

ul,
ol {
  list-style: none;
}

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


/* ── 3. Site Layout ──────────────────────────── */
.site {
  display: flex;
  min-height: 100svh;
}

/* ── 4. Sidebar ──────────────────────────────── */
.sidebar {
  position: fixed;
  top: 0;
  left: 0;
  width: var(--sidebar-w);
  height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding: var(--s12) var(--s10);
  z-index: 50;
  overflow-y: auto;
}

.sidebar__name-link {
  display: block;
  transition: opacity var(--ease);
}

.sidebar__name-link:hover {
  opacity: 0.55;
}

.sidebar__name {
  font-size: var(--t-lg);
  font-weight: 500;
  letter-spacing: -0.01em;
  line-height: 1.2;
}

.sidebar__role {
  font-size: var(--t-sm);
  color: var(--text-muted);
  margin-top: 4px;
  font-weight: 400;
}

.sidebar__bottom {
  display: flex;
  flex-direction: column;
  gap: var(--s3);
}

.sidebar__social {
  font-size: var(--t-xs);
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
  transition: color var(--ease);
}

.sidebar__social:hover {
  color: var(--text);
}


/* ── 5. Side Navigation ──────────────────────── */
.side-nav {
  margin-top: var(--s12);
  display: flex;
  flex-direction: column;
  gap: var(--s4);
}

.side-nav__item {
  display: flex;
  align-items: center;
  gap: 12px;
  cursor: pointer;
}

.side-nav__line {
  display: block;
  width: 18px;
  height: 1px;
  background: var(--text-muted);
  transition: width 0.35s ease, background 0.35s ease;
  flex-shrink: 0;
}

.side-nav__label {
  font-size: var(--t-xs);
  font-weight: 500;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-muted);
  transition: color 0.35s ease;
}

.side-nav__label--long {
  letter-spacing: 0.04em;
  white-space: nowrap;
}

/* hover state */
.side-nav__item:hover .side-nav__line {
  width: 28px;
  background: var(--text-sec);
}

.side-nav__item:hover .side-nav__label {
  color: var(--text-sec);
}

/* active state (set via JS) */
.side-nav__item.active .side-nav__line {
  width: 40px;
  background: var(--text);
}

.side-nav__item.active .side-nav__label {
  color: var(--text);
}


/* ── 6. Mobile Navigation ────────────────────── */
.mobile-nav {
  display: none;
  /* shown only on mobile via media query */
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-h);
  background: rgba(250, 250, 248, 0.92);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border-light);
  z-index: 100;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--s6);
}

.mobile-nav__name {
  font-size: var(--t-base);
  font-weight: 500;
  letter-spacing: -0.01em;
}

.mobile-nav__burger {
  display: flex;
  flex-direction: column;
  gap: 5px;
  width: 24px;
  padding: 4px 0;
}

.mobile-nav__burger span {
  display: block;
  height: 1.5px;
  background: var(--text);
  transition: transform var(--ease), opacity var(--ease);
  transform-origin: center;
}

.mobile-nav__burger.open span:first-child {
  transform: translateY(3.25px) rotate(45deg);
}

.mobile-nav__burger.open span:last-child {
  transform: translateY(-3.25px) rotate(-45deg);
}

/* Mobile menu overlay */
.mobile-menu {
  display: none;
  position: fixed;
  inset: var(--nav-h) 0 0;
  background: var(--bg);
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--s8);
  z-index: 99;
  transform: translateX(100%);
  transition: transform 0.35s cubic-bezier(0.4, 0, 0.2, 1);
}

.mobile-menu.open {
  transform: translateX(0);
}

.mobile-menu__link {
  font-size: var(--t-2xl);
  font-weight: 300;
  letter-spacing: -0.02em;
  color: var(--text-sec);
  transition: color var(--ease);
}

.mobile-menu__link:hover {
  color: var(--text);
}


/* ── 7. Content (right panel) ────────────────── */
.content {
  margin-left: var(--sidebar-w);
  flex: 1;
  min-width: 0;
}

.content-section {
  padding: var(--s20) var(--s12);
  border-top: 1px solid var(--border-light);
}

.content-section:first-child {
  border-top: none;
}


/* ── 8. About Section ────────────────────────── */
#about {
  min-height: 100svh;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.intro__name {
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 500;
  letter-spacing: -0.03em;
  color: var(--text);
  margin-bottom: var(--s6);
}

.intro__text {
  font-size: clamp(var(--t-lg), 2vw, var(--t-xl));
  font-weight: 400;
  line-height: 1.75;
  color: var(--text-sec);
  max-width: 560px;
}

.intro__text strong,
.intro__text b {
  color: var(--text);
  font-weight: 500;
}

.intro__links {
  display: flex;
  gap: var(--s6);
  margin-top: var(--s8);
  flex-wrap: wrap;
}

.intro__link {
  font-size: var(--t-sm);
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text-sec);
  position: relative;
  transition: color var(--ease);
}

.intro__link::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  right: 0;
  height: 1px;
  background: var(--text);
  transform: scaleX(0);
  transform-origin: right;
  transition: transform 0.28s ease;
}

.intro__link:hover {
  color: var(--text);
}

.intro__link:hover::after {
  transform: scaleX(1);
  transform-origin: left;
}


/* ── Section label shared ────────────────────── */
.section-label {
  display: block;
  font-size: var(--t-xs);
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: var(--s3);
}

.section-title {
  font-size: var(--t-3xl);
  font-weight: 400;
  letter-spacing: -0.02em;
  line-height: 1.2;
  margin-bottom: var(--s12);
}


/* ── 9. Projects Section ─────────────────────── */

/* ── All Work Timeline
   Layout: bairui.dev style — constrained centered block, date absolute-left
─────────────────────────────────────────────── */
.timeline-section-label {
  max-width: none;
  margin: var(--s12) 0 var(--s2);
  font-size: var(--t-xs);
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-muted);
}

.projects-timeline {
  max-width: none;
  margin: var(--s4) 0 0;
  position: relative;
}

/* Vertical axis line */
.projects-timeline::before {
  content: '';
  position: absolute;
  left: 3px;
  top: 0;
  bottom: 0;
  width: 1.5px;
  background: var(--border);
  pointer-events: none;
}

.timeline-item {
  position: relative;
  display: block;
  padding-left: 148px;
  padding-bottom: var(--s10);
  color: inherit;
  text-decoration: none;
}

.timeline-item:hover .timeline-item__info {
  opacity: 0.65;
}

.timeline-item__info {
  transition: opacity var(--ease);
}

/* Dot on the axis */
.timeline-item::before {
  content: '';
  position: absolute;
  left: 0;
  top: 11px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--bg);
  border: 2px solid var(--text-sec);
  z-index: 1;
}

/* Date: absolute, sits between dot and content */
.timeline-item__date {
  position: absolute;
  left: 18px;
  top: 5px;
  font-size: var(--t-xs);
  font-weight: 600;
  color: var(--text-sec);
  white-space: nowrap;
  font-variant-numeric: tabular-nums;
  line-height: 1.5;
}

/* Image-left / info-right row */
.timeline-item__content {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: var(--s5, 1.25rem);
  align-items: start;
}

.timeline-item__info {
  display: flex;
  flex-direction: column;
  gap: var(--s3);
}

.timeline-item__info-top {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--s4);
}

.timeline-item__type {
  font-size: var(--t-xs);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
}

/* Title */
.timeline-item__title {
  font-size: var(--t-xl);
  font-weight: 400;
  letter-spacing: -0.02em;
  line-height: 1.3;
  color: var(--text);
  margin-bottom: 0;
  flex: 1;
}

/* Project image — landscape 2:1 */
.timeline-item__img {
  position: relative;
  overflow: hidden;
  width: 100%;
  aspect-ratio: 2 / 1;
  border-radius: var(--radius);
  background: var(--bg-alt);
  flex-shrink: 0;
}

.timeline-item__img img:not(.timeline-item__award-badge) {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.65s cubic-bezier(0.16, 1, 0.3, 1);
}

.timeline-item:hover .timeline-item__img img:not(.timeline-item__award-badge) {
  transform: scale(1.03);
}

.timeline-item__img--dark {
  background: #1c1c1a;
}

/* Frosted-glass overlay on hover */
.timeline-item__img::after {
  content: '';
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.12);
  backdrop-filter: blur(5px);
  -webkit-backdrop-filter: blur(5px);
  opacity: 0;
  transition: opacity 0.3s ease;
  z-index: 2;
  pointer-events: none;
}

.timeline-item:hover .timeline-item__img::after {
  opacity: 1;
}

/* One-line project description */
.timeline-item__desc {
  font-size: var(--t-sm);
  color: var(--text-sec);
  line-height: 1.65;
}

/* Technique keywords — plain text, no pill boxes */
.timeline-item__tech {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 0;
}

.timeline-item__tech .tag {
  background: none;
  padding: 0;
  border-radius: 0;
  font-size: var(--t-xs);
  color: var(--text-muted);
  font-weight: 400;
  letter-spacing: 0;
}

.timeline-item__tech .tag+.tag::before {
  content: ' · ';
  color: var(--text-muted);
  margin: 0 1px;
}

.timeline-item__tech .tag--review {
  background: none;
  color: #B45309;
}

.timeline-item__tech .tag--progress {
  background: none;
  color: #6D28D9;
}

.timeline-item__tech .tag--award {
  background: none;
  color: #92400E;
}

/* Arrow */
.timeline-item__arrow {
  font-size: var(--t-sm);
  color: var(--text-muted);
  transition: color var(--ease), transform var(--ease);
  flex-shrink: 0;
}

.timeline-item:hover .timeline-item__arrow {
  color: var(--text);
  transform: translateX(4px);
}

/* ── Section title row with view toggle ─────── */
.section-title-row {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: var(--s4);
  margin-bottom: var(--s12);
}

.section-title-row .section-title {
  margin-bottom: 0;
}

.view-toggle {
  display: flex;
  gap: var(--s3);
  align-items: center;
  flex-shrink: 0;
  padding-bottom: 4px;
}

.view-toggle__btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  height: 20px;
  border: none;
  background: none;
  cursor: pointer;
  color: var(--text-muted);
  transition: color var(--ease);
  padding: 0;
}

.view-toggle__btn svg {
  flex-shrink: 0;
}

.view-toggle__label {
  font-size: var(--t-sm);
  line-height: 1;
}

.view-toggle__btn:hover {
  color: var(--text-sec);
}

.view-toggle__btn.active {
  color: var(--text);
}

/* ── Grid category filters ───────────────────── */
.grid-filters {
  flex-wrap: wrap;
  gap: var(--s2);
  margin-bottom: var(--s6);
}

.grid-filter__btn {
  font-size: var(--t-xs);
  font-weight: 400;
  padding: 4px var(--s4) 4px;
  border: none;
  border-bottom: 1.5px solid transparent;
  background: none;
  color: var(--text-muted);
  cursor: pointer;
  letter-spacing: 0.02em;
  transition: color var(--ease), border-color var(--ease);
}

.grid-filter__btn:hover {
  color: var(--text-sec);
}

.grid-filter__btn.active {
  color: var(--text);
  font-weight: 500;
  border-bottom-color: var(--text);
}

/* ── Grid view override ──────────────────────── */
.projects-timeline.grid-view {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--s8);
}

.projects-timeline.grid-view::before {
  display: none;
}

.projects-timeline.grid-view .timeline-item {
  padding-left: 0;
  padding-bottom: 0;
  border: none;
  background: none;
  border-radius: 0;
  overflow: visible;
  position: relative;
  transition: none;
}

.projects-timeline.grid-view .timeline-item:hover .timeline-item__info {
  opacity: 1;
}

.projects-timeline.grid-view .timeline-item::before {
  display: none;
}

.projects-timeline.grid-view .timeline-item__content {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.projects-timeline.grid-view .timeline-item__img {
  border-radius: var(--radius);
  aspect-ratio: 4 / 3;
  width: 100%;
  overflow: hidden;
}

/* Darker, unblurred overlay for grid hover */
.projects-timeline.grid-view .timeline-item__img::after {
  background: rgba(0, 0, 0, 0.4);
  backdrop-filter: none;
  -webkit-backdrop-filter: none;
}

/* Hide the original date span in grid view (year shown via img::before instead) */
.projects-timeline.grid-view .timeline-item__date {
  display: none;
}

/* Year rendered from data-year attr, inside image so it positions correctly */
.projects-timeline.grid-view .timeline-item__img::before {
  content: attr(data-year);
  position: absolute;
  bottom: var(--s4);
  right: var(--s4);
  z-index: 4;
  font-size: var(--t-sm);
  font-weight: 600;
  color: rgba(255, 255, 255, 0.92);
  opacity: 0;
  transform: translateY(8px);
  transition: opacity 0.3s ease, transform 0.3s ease;
  white-space: nowrap;
  letter-spacing: 0.02em;
  pointer-events: none;
}

.projects-timeline.grid-view .timeline-item:hover .timeline-item__img::before {
  opacity: 1;
  transform: translateY(0);
}

.projects-timeline.grid-view .timeline-item__info {
  padding: var(--s3) 0 0;
  gap: var(--s2);
}

.projects-timeline.grid-view .timeline-item__title {
  font-size: var(--t-base);
}

/* Short grid-only description */
.timeline-item__desc--grid {
  display: none;
}

.projects-timeline.grid-view .timeline-item__desc {
  display: none;
}

.projects-timeline.grid-view .timeline-item__desc--grid {
  display: block;
  font-size: var(--t-sm);
  color: var(--text-sec);
  line-height: 1.65;
}

/* Tags: below image, plain text with dot separators */
.projects-timeline.grid-view .timeline-item__tech {
  flex-direction: row;
  flex-wrap: wrap;
  gap: 0;
}

.projects-timeline.grid-view .timeline-item__tech .tag {
  background: none;
  padding: 0;
  border-radius: 0;
  font-size: var(--t-xs);
  font-weight: 400;
  color: var(--text-muted);
  letter-spacing: 0;
}

.projects-timeline.grid-view .timeline-item__tech .tag+.tag::before {
  content: ' · ';
  color: var(--text-muted);
  margin: 0 1px;
}

.projects-timeline.grid-view .timeline-item__tech .tag--award {
  color: #92400E;
}

.projects-timeline.grid-view .timeline-item__tech .tag--progress {
  color: #6D28D9;
}

.projects-timeline.grid-view .timeline-item__tech .tag--review {
  color: #B45309;
}


.projects-timeline.grid-view .timeline-item__arrow {
  display: none;
}

.timeline-item.timeline-item--hidden {
  display: none;
}

@keyframes gridItemIn {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.projects-timeline.is-filtering .timeline-item:not(.timeline-item--hidden) {
  animation: gridItemIn 0.5s cubic-bezier(0.16, 1, 0.3, 1) both;
}

.projects-timeline.grid-view .timeline-item__award-badge {
  width: 176px;
}


/* ── 10. Project Cards ───────────────────────── */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--s6);
  /* default align-items: stretch — cards fill row height equally */
}

/* 4-column featured grid */
.projects-grid--4 {
  grid-template-columns: repeat(4, 1fr);
  gap: var(--s4);
  align-items: stretch;
}

.project-card {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow);
  height: 100%;
  /* fill grid cell so all cards in a row are equal height */
  will-change: transform;
  transform: translateZ(0);
  transition:
    transform var(--ease-spring),
    box-shadow var(--ease-spring),
    opacity 0.3s ease;
}

.project-card:hover {
  transform: translateY(-4px) translateZ(0);
  box-shadow: var(--shadow-hover);
}

/* Research paper card — styled placeholder instead of image */
.project-card__img--paper {
  background: none;
}

.project-card__paper-bg {
  width: 100%;
  height: 100%;
  background: #1c1c1a;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: opacity var(--ease);
}

.project-card__paper-bg--alt {
  background: #1e2030;
}

.project-card:hover .project-card__paper-bg {
  opacity: 0.8;
}

.project-card__paper-tag {
  font-size: var(--t-xs);
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.3);
}

/* Status tags */
.tag--review {
  background: #FEF3C7;
  color: #92400E;
}

.tag--progress {
  background: #EDE9FE;
  color: #5B21B6;
}

.project-card__link {
  display: flex;
  flex-direction: column;
  height: 100%;
}

/* Fixed-ratio image slot */
.project-card__img {
  aspect-ratio: 16 / 10;
  overflow: hidden;
  background: var(--bg-alt);
  flex-shrink: 0;
}

.project-card__img img:not(.project-card__award-badge) {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.65s cubic-bezier(0.16, 1, 0.3, 1);
}

.project-card:hover .project-card__img img:not(.project-card__award-badge) {
  transform: scale(1.05);
}

.project-card__body {
  padding: var(--s6);
  display: flex;
  flex-direction: column;
  flex: 1;
}

.project-card__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  margin-bottom: var(--s3);
}

.tag {
  font-size: var(--t-xs);
  font-weight: 500;
  padding: 2px 9px;
  border-radius: 100px;
  background: var(--bg-alt);
  color: var(--text-sec);
  letter-spacing: 0.02em;
}

.project-card__category {
  font-size: var(--t-xs);
  color: var(--text-muted);
  font-weight: 400;
  margin-bottom: var(--s2);
}

.project-card__title {
  font-size: var(--t-base);
  font-weight: 500;
  letter-spacing: -0.01em;
  line-height: 1.3;
  color: var(--text);
  margin-bottom: var(--s2);
}

.project-card__desc {
  font-size: var(--t-sm);
  color: var(--text-sec);
  line-height: 1.65;
  flex: 1;
  margin-bottom: var(--s3);
}

.project-card__meta {
  font-size: var(--t-xs);
  font-weight: 500;
  margin-top: auto;
}

.project-card__meta--award {
  color: var(--accent);
}

.project-card__meta--lab {
  color: var(--text-muted);
}

/* Featured card variant — image dominant, hover overlay, title below */
.project-card--featured {
  background: none;
  border-radius: 0;
  box-shadow: none;
}

.project-card--featured:hover {
  transform: none;
  box-shadow: none;
}

.project-card--featured .project-card__img {
  position: relative;
  border-radius: var(--radius-lg);
  margin-bottom: var(--s3);
}

.project-card__overlay {
  position: absolute;
  inset: 0;
  border-radius: var(--radius-lg);
  background: linear-gradient(to top, rgba(0, 0, 0, 0.6) 0%, transparent 60%);
  backdrop-filter: blur(0px);
  -webkit-backdrop-filter: blur(0px);
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  padding: var(--s6) var(--s6) var(--s8);
  opacity: 0;
  transition: opacity 0.3s ease, backdrop-filter 0.3s ease;
  pointer-events: none;
  z-index: 2;
}

.project-card--featured:hover .project-card__overlay {
  opacity: 1;
  backdrop-filter: blur(5px);
  -webkit-backdrop-filter: blur(5px);
}

.project-card__award-badge {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 108px;
  height: auto;
  transform: translate(-50%, -50%) scale(0.85);
  opacity: 0;
  transition: opacity 0.3s ease, transform 0.3s ease;
  pointer-events: none;
  z-index: 3;
}

.project-card--featured:hover .project-card__award-badge {
  opacity: 1;
  transform: translate(-50%, -50%) scale(1);
}

/* Award badge on timeline items — visually proportioned to shorter container (aspect 2:1 vs featured 16:10) */
.timeline-item__award-badge {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 88px;
  height: auto;
  transform: translate(-50%, -50%) scale(0.85);
  opacity: 0;
  transition: opacity 0.3s ease, transform 0.3s ease;
  pointer-events: none;
  z-index: 3;
}

.timeline-item:hover .timeline-item__award-badge {
  opacity: 1;
  transform: translate(-50%, -50%) scale(1);
}

.timeline-item__award-badge--sm {
  width: 60px;
}

.projects-timeline.grid-view .timeline-item__award-badge--sm {
  width: 112px;
}

.timeline-item__coming-soon {
  position: absolute;
  bottom: var(--s4);
  left: var(--s4);
  z-index: 4;
  font-size: var(--t-xs);
  font-weight: 500;
  color: rgba(255, 255, 255, 0.88);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  opacity: 0;
  transform: translateY(4px);
  transition: opacity 0.3s ease, transform 0.3s ease;
  pointer-events: none;
}

.projects-timeline.grid-view .timeline-item:hover .timeline-item__coming-soon {
  opacity: 1;
  transform: translateY(0);
}

.project-card__overlay-year {
  font-size: var(--t-xs);
  color: rgba(255, 255, 255, 0.65);
  margin-bottom: var(--s1);
}

.project-card__overlay-info {
  font-size: var(--t-sm);
  color: #fff;
  font-weight: 500;
  line-height: 1.4;
}

.project-card--featured .project-card__title {
  padding: 0;
  margin: 0;
  font-size: var(--t-sm);
  color: var(--text);
}


/* ── 11. Research Section ────────────────────── */
.pub-list {
  display: flex;
  flex-direction: column;
}

.pub-item {
  display: grid;
  grid-template-columns: 90px 1fr;
  gap: var(--s6);
  padding: var(--s8) 0;
  align-items: start;
}

.pub-meta {
  display: flex;
  flex-direction: column;
  gap: var(--s2);
  padding-top: 3px;
}

.pub-year {
  font-size: var(--t-sm);
  font-weight: 500;
  font-variant-numeric: tabular-nums;
}


.pub-title {
  font-size: var(--t-base);
  font-weight: 500;
  color: var(--text);
  line-height: 1.5;
  letter-spacing: -0.01em;
  margin-bottom: var(--s2);
}

.pub-authors {
  font-size: var(--t-sm);
  color: var(--text-sec);
  line-height: 1.65;
  margin-bottom: var(--s2);
}

.pub-footnote {
  font-size: var(--t-xs);
  color: var(--text-muted);
  margin-top: calc(-1 * var(--s6));
  margin-bottom: var(--s8);
}

.pub-venue {
  font-size: var(--t-sm);
  color: var(--text-muted);
  font-style: italic;
  line-height: 1.65;
}

.pub-citation {
  font-size: var(--t-base);
  color: var(--text-sec);
  line-height: 1.75;
}

.pub-citation em {
  font-style: italic;
  color: var(--text);
}


/* ── 12. Awards Section ──────────────────────── */
.awards-list {
  display: flex;
  flex-direction: column;
}

.award-item {
  display: grid;
  grid-template-columns: 55px 1fr;
  gap: var(--s8);
  padding: var(--s5, 1.25rem) 0;
  align-items: start;
}

.award-year {
  font-size: var(--t-sm);
  font-weight: 500;
  color: var(--text-muted);
  font-variant-numeric: tabular-nums;
  padding-top: 2px;
}

.award-name {
  font-size: var(--t-base);
  font-weight: 500;
  letter-spacing: -0.01em;
  margin-bottom: 3px;
}

.award-detail {
  font-size: var(--t-sm);
  color: var(--text-sec);
}


/* ── 13. Playground Section ──────────────────── */
.playground-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--s6);
}

.sketch-card {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--border-light);
  transition: box-shadow var(--ease-spring), transform var(--ease-spring);
  will-change: transform;
  transform: translateZ(0);
}

.sketch-card:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-3px) translateZ(0);
}

.sketch-card__canvas-wrap {
  width: 100%;
  aspect-ratio: 4 / 3;
  background: #111;
  position: relative;
  overflow: hidden;
}

.sketch-card__canvas-wrap canvas,
.sketch-card__canvas-wrap iframe {
  width: 100% !important;
  height: 100% !important;
  display: block;
}

.sketch-card__label {
  padding: var(--s4) var(--s6);
  font-size: var(--t-sm);
  font-weight: 500;
  color: var(--text-sec);
  border-top: 1px solid var(--border-light);
}

/* External-link sketch card — opens in new tab (use for camera/keyboard sketches) */
.sketch-card--external {
  display: block;
  text-decoration: none;
}

.sketch-card--external .sketch-card__canvas-wrap {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--s3);
  cursor: pointer;
}

.sketch-card__launch-icon {
  font-size: 2rem;
  line-height: 1;
  color: rgba(255, 255, 255, 0.18);
  transition: color var(--ease), transform var(--ease);
}

.sketch-card__launch-hint {
  font-size: var(--t-xs);
  font-weight: 500;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.18);
  transition: color var(--ease);
}

.sketch-card--external:hover .sketch-card__launch-icon {
  color: rgba(255, 255, 255, 0.55);
  transform: translate(3px, -3px);
}

.sketch-card--external:hover .sketch-card__launch-hint {
  color: rgba(255, 255, 255, 0.35);
}

.sketch-card--external:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-3px) translateZ(0);
}

/* ── 13b. Sketchbook (viewer + list) ─────────── */
.sketchbook {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 240px;
  gap: var(--s6);
  margin-top: var(--s4);
  align-items: stretch;
}

.sketchbook__viewer {
  position: relative;
  aspect-ratio: 16 / 10;
  background: #0f0f0e;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--border-light);
}

.sketchbook__viewer:fullscreen,
.sketchbook__viewer.is-fullscreen {
  aspect-ratio: auto;
  width: 100vw;
  height: 100vh;
  border-radius: 0;
  border: 0;
}

.sketchbook__viewer:-webkit-full-screen {
  aspect-ratio: auto;
  width: 100vw;
  height: 100vh;
  border-radius: 0;
  border: 0;
}

.sketchbook__stage {
  position: absolute;
  inset: 0;
  overflow: hidden;
  background: #0f0f0e;
}

.sketchbook__stage canvas,
.sketchbook__stage iframe {
  width: 100% !important;
  height: 100% !important;
  display: block;
  border: 0;
}

.sketchbook__caption {
  position: absolute;
  left: var(--s4);
  bottom: var(--s3);
  color: rgba(255, 255, 255, 0.7);
  font-size: var(--t-xs);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  pointer-events: none;
  z-index: 4;
  opacity: 0;
  transition: opacity var(--ease);
}

.sketchbook__viewer:hover .sketchbook__caption {
  opacity: 1;
}

.sketchbook__controls {
  position: absolute;
  top: var(--s3);
  right: var(--s3);
  z-index: 5;
  display: flex;
  gap: 6px;
}

.sketchbook__ctrl {
  width: 32px;
  height: 32px;
  border-radius: 6px;
  background: rgba(15, 15, 14, 0.55);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid rgba(255, 255, 255, 0.08);
  color: rgba(255, 255, 255, 0.7);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0;
  cursor: pointer;
  opacity: 0;
  transform: translateY(-4px);
  transition: color var(--ease), background var(--ease),
    opacity var(--ease), transform var(--ease);
}

.sketchbook__viewer:hover .sketchbook__ctrl,
.sketchbook__viewer:focus-within .sketchbook__ctrl,
.sketchbook__viewer:fullscreen .sketchbook__ctrl,
.sketchbook__viewer.is-fullscreen .sketchbook__ctrl {
  opacity: 1;
  transform: translateY(0);
}

.sketchbook__ctrl:hover {
  color: #fff;
  background: rgba(15, 15, 14, 0.8);
}

.sketchbook__ctrl-icon {
  display: inline-block;
  width: 14px;
  height: 14px;
  position: relative;
}

/* expand icon: two small L-corners */
.sketchbook__ctrl-icon--expand::before,
.sketchbook__ctrl-icon--expand::after {
  content: '';
  position: absolute;
  width: 6px;
  height: 6px;
  border: 1.5px solid currentColor;
}

.sketchbook__ctrl-icon--expand::before {
  top: 0;
  left: 0;
  border-right: 0;
  border-bottom: 0;
}

.sketchbook__ctrl-icon--expand::after {
  bottom: 0;
  right: 0;
  border-left: 0;
  border-top: 0;
}

/* collapse icon: mirrored corners, pointing inward */
.sketchbook__ctrl-icon--collapse {
  display: none;
}

.sketchbook__ctrl-icon--collapse::before,
.sketchbook__ctrl-icon--collapse::after {
  content: '';
  position: absolute;
  width: 6px;
  height: 6px;
  border: 1.5px solid currentColor;
}

.sketchbook__ctrl-icon--collapse::before {
  top: 0;
  right: 0;
  border-left: 0;
  border-bottom: 0;
}

.sketchbook__ctrl-icon--collapse::after {
  bottom: 0;
  left: 0;
  border-right: 0;
  border-top: 0;
}

.sketchbook__viewer:fullscreen .sketchbook__ctrl-icon--expand,
.sketchbook__viewer.is-fullscreen .sketchbook__ctrl-icon--expand {
  display: none;
}

.sketchbook__viewer:fullscreen .sketchbook__ctrl-icon--collapse,
.sketchbook__viewer.is-fullscreen .sketchbook__ctrl-icon--collapse {
  display: inline-block;
}

.sketchbook__list {
  display: flex;
  flex-direction: column;
  align-self: stretch;
  min-width: 0;
}

.sketchbook__item {
  background: none;
  border: 0;
  border-bottom: 1px solid var(--border-light);
  padding: var(--s4) var(--s2);
  color: var(--text-sec);
  font-family: inherit;
  font-size: var(--t-sm);
  cursor: pointer;
  display: grid;
  grid-template-columns: 28px 1fr auto;
  align-items: baseline;
  gap: var(--s3);
  text-align: left;
  transition: color var(--ease), padding var(--ease),
    background var(--ease);
}

.sketchbook__item:first-child {
  border-top: 1px solid var(--border-light);
}

.sketchbook__item:hover {
  color: var(--text);
  padding-left: var(--s4);
}

.sketchbook__item.is-active {
  color: var(--text);
  font-weight: 500;
}

.sketchbook__item-num {
  font-size: var(--t-xs);
  color: var(--text-muted);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.05em;
}

.sketchbook__item-name {
  line-height: 1.3;
  min-width: 0;
}

.sketchbook__item-tag {
  font-size: var(--t-xs);
  color: var(--text-muted);
  letter-spacing: 0.05em;
  text-transform: lowercase;
}

.sketchbook__item-tag:empty {
  display: none;
}

/* Overlay shown at sketch start for interaction hint */
.sketchbook__hint {
  position: absolute;
  inset: 0;
  z-index: 6;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--s6);
  background: rgba(10, 10, 16, 0.55);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  opacity: 1;
  transition: opacity 0.35s ease;
}

.sketchbook__hint.is-hidden {
  opacity: 0;
  pointer-events: none;
}

.sketchbook__hint-inner {
  max-width: 440px;
  text-align: center;
  color: #fff;
}

.sketchbook__hint-eyebrow {
  font-size: var(--t-xs);
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.55);
  margin-bottom: var(--s3);
}

.sketchbook__hint-body {
  font-size: var(--t-lg);
  font-weight: 300;
  line-height: 1.55;
  color: rgba(255, 255, 255, 0.92);
  margin-bottom: var(--s6);
  letter-spacing: -0.005em;
}

.sketchbook__hint-sub {
  display: inline-block;
  margin-top: var(--s2);
  font-size: var(--t-sm);
  color: rgba(255, 255, 255, 0.55);
}

/* Start button — same ghost outline as the Read Paper / site buttons, inverted for dark overlay */
.sketchbook__hint-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--s2);
  appearance: none;
  -webkit-appearance: none;
  background: transparent;
  color: #fff;
  border: 1px solid rgba(255, 255, 255, 0.45);
  border-radius: var(--radius);
  padding: 0.625rem var(--s8);
  font-family: inherit;
  font-size: var(--t-sm);
  font-weight: 500;
  letter-spacing: 0.02em;
  cursor: pointer;
  transition: border-color var(--ease), background var(--ease), transform var(--ease);
}

.sketchbook__hint-btn:hover {
  border-color: #fff;
  background: rgba(255, 255, 255, 0.08);
  transform: translateY(-1px);
}

.sketchbook__hint-btn:active {
  transform: translateY(0);
}

@media (max-width: 1350px) {
  .sketchbook {
    grid-template-columns: 1fr;
    gap: var(--s4);
  }

  .sketchbook__viewer,
  .sketchbook__list {
    width: 100%;
  }

  .sketchbook__list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: var(--s2);
    border: 0;
  }

  .sketchbook__item {
    border: 1px solid var(--border-light);
    border-radius: var(--radius);
    padding: var(--s3) var(--s4);
    white-space: normal;
    min-height: 60px;
    align-items: center;
  }

  .sketchbook__item:first-child {
    border-top: 1px solid var(--border-light);
  }

  .sketchbook__item:hover {
    padding-left: var(--s4);
  }
}

@media (max-width: 768px) {
  .sketchbook__item {
    grid-template-columns: 28px minmax(0, 1fr);
  }

  .sketchbook__item-tag {
    display: none;
  }
}

@media (max-width: 640px) {
  .sketchbook__list {
    grid-template-columns: 1fr;
  }
}


/* ── 14. Contact Section ─────────────────────── */
.contact__title {
  font-size: clamp(var(--t-3xl), 5vw, var(--t-4xl));
  font-weight: 300;
  letter-spacing: -0.03em;
  line-height: 1.1;
  margin: var(--s4) 0;
}

.contact__sub {
  font-size: var(--t-lg);
  color: var(--text-sec);
  margin-bottom: var(--s8);
  max-width: 400px;
}

.contact__email {
  display: inline-block;
  font-size: var(--t-2xl);
  font-weight: 300;
  letter-spacing: -0.02em;
  border-bottom: 1px solid var(--border);
  padding-bottom: 2px;
  margin-bottom: var(--s8);
  transition: border-color var(--ease);
}

.contact__email:hover {
  border-color: var(--text);
}

.contact__socials {
  display: flex;
  gap: var(--s6);
  flex-wrap: wrap;
}

.contact__soc {
  font-size: var(--t-xs);
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-sec);
  position: relative;
  transition: color var(--ease);
}

.contact__soc::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  right: 0;
  height: 1px;
  background: var(--text);
  transform: scaleX(0);
  transform-origin: right;
  transition: transform 0.28s ease;
}

.contact__soc:hover {
  color: var(--text);
}

.contact__soc:hover::after {
  transform: scaleX(1);
  transform-origin: left;
}


/* ── 15. Footer ──────────────────────────────── */
.footer {
  padding: var(--s6) var(--s12);
}

.footer__text {
  font-size: var(--t-xs);
  color: var(--text-muted);
  letter-spacing: 0.04em;
}


/* ── 16. Reveal Animations ───────────────────── */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition:
    opacity 0.65s cubic-bezier(0.16, 1, 0.3, 1),
    transform 0.65s cubic-bezier(0.16, 1, 0.3, 1);
}

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

/* stagger for children */
.reveal:nth-child(2) {
  transition-delay: 70ms;
}

.reveal:nth-child(3) {
  transition-delay: 140ms;
}

.reveal:nth-child(4) {
  transition-delay: 210ms;
}

.reveal:nth-child(5) {
  transition-delay: 280ms;
}

.reveal:nth-child(6) {
  transition-delay: 350ms;
}

/* Grid items stagger */
.projects-grid .project-card.reveal:nth-child(1) {
  transition-delay: 0ms;
}

.projects-grid .project-card.reveal:nth-child(2) {
  transition-delay: 80ms;
}

.projects-grid .project-card.reveal:nth-child(3) {
  transition-delay: 160ms;
}

.projects-grid .project-card.reveal:nth-child(4) {
  transition-delay: 240ms;
}

.projects-grid .project-card.reveal:nth-child(5) {
  transition-delay: 320ms;
}

.projects-grid .project-card.reveal:nth-child(6) {
  transition-delay: 400ms;
}

.projects-grid .project-card.reveal:nth-child(7) {
  transition-delay: 480ms;
}

.projects-grid .project-card.reveal:nth-child(8) {
  transition-delay: 560ms;
}


/* ── 17. Buttons ─────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--s2);
  padding: 0.625rem var(--s6);
  font-size: var(--t-sm);
  font-weight: 500;
  border-radius: var(--radius);
  transition: all var(--ease);
  white-space: nowrap;
}

.btn--dark {
  background: var(--text);
  color: var(--bg);
}

.btn--dark:hover {
  background: #2a2a28;
  transform: translateY(-1px);
}

.btn--ghost {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
  cursor: pointer;
}

.btn--ghost:hover {
  border-color: var(--text);
  transform: translateY(-1px);
}

.btn--ghost-disabled {
  color: var(--text-muted);
  border-color: var(--border);
  cursor: default;
}

.btn--ghost-disabled:hover {
  border-color: var(--border);
  transform: none;
}

/* Citation block with copy button */
.citation-block {
  position: relative;
  margin: var(--s4) 0 var(--s10);
}

.citation-block__pre {
  white-space: pre-wrap;
  background: var(--bg-alt);
  border-radius: var(--radius-lg);
  padding: var(--s6);
  padding-right: 7rem;
  font-family: 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: var(--t-sm);
  line-height: 1.7;
  color: var(--text-sec);
  overflow: auto;
  margin: 0;
}

.citation-block__copy {
  position: absolute;
  top: var(--s4);
  right: var(--s4);
  padding: 0.375rem 0.875rem;
  font-size: var(--t-xs);
  font-weight: 500;
  letter-spacing: 0.04em;
  color: var(--text);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  transition: border-color var(--ease), transform var(--ease), background var(--ease);
}

.citation-block__copy:hover {
  border-color: var(--text);
  transform: translateY(-1px);
}

.citation-block__copy:active {
  transform: translateY(0);
  background: var(--bg-alt);
}

/* Responsive 16:9 YouTube embed wrapper used in project pages */
.project-page__video {
  position: relative;
  width: 100%;
  padding-bottom: 56.25%;
  height: 0;
  border-radius: var(--radius-lg);
  overflow: hidden;
  margin: var(--s8) 0;
  background: #000;
}
.project-page__video iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border: 0;
}

/* Header byline row on publication pages: gray meta on the left, action buttons on the right */
.project-page__byline {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--s6);
  flex-wrap: wrap;
  margin-top: var(--s4);
}

.project-page__byline-text {
  flex: 1 1 auto;
  min-width: 0;
}

.project-page__byline-text .project-page__year {
  margin: 0;
}

.project-page__byline-text .project-page__authors {
  margin-top: var(--s2);
}

.project-page__byline-text .project-page__byline-actions {
  margin-top: var(--s4);
  justify-content: flex-start;
}

.project-page__byline-actions {
  flex: 0 0 auto;
  display: flex;
  gap: var(--s3);
  flex-wrap: wrap;
  justify-content: flex-end;
  align-self: center;
}

@media (max-width: 640px) {
  .project-page__byline {
    flex-direction: column;
  }

  .project-page__byline-actions {
    justify-content: flex-start;
  }
}



/* ── 18. Project Detail Pages ────────────────── */
.project-page {
  padding: var(--s12) 0 var(--s24);
}

.project-page-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--s8);
  z-index: 100;
  background: rgba(250, 250, 248, 0.92);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border-light);
}

.project-page-nav__back {
  display: flex;
  align-items: center;
  gap: var(--s2);
  font-size: var(--t-sm);
  font-weight: 500;
  color: var(--text-sec);
  transition: color var(--ease);
}

.project-page-nav__back:hover {
  color: var(--text);
}

.project-page-nav__home {
  font-size: var(--t-sm);
  font-weight: 500;
  letter-spacing: -0.01em;
  transition: opacity var(--ease);
}

.project-page-nav__home:hover {
  opacity: 0.55;
}

.project-page__inner {
  max-width: 900px;
  margin: calc(var(--nav-h) + var(--s12)) auto 0;
  padding: 0 var(--s8);
}

.project-page__hero {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  background: var(--bg-alt);
  border-radius: var(--radius-lg);
  overflow: hidden;
  margin-bottom: var(--s10);
}

.project-page__hero img:not(.project-page__hero-award) {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.project-page__hero--sentverse img:not(.project-page__hero-award) {
  object-position: center 50%;
}

/* Award badge overlay on project hero (hover) */
.project-page__hero-award {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 200px;
  height: auto;
  transform: translate(-50%, -50%) scale(0.88);
  opacity: 0;
  transition: opacity 0.3s ease, transform 0.3s ease;
  pointer-events: none;
  z-index: 3;
}

.project-page__hero:hover .project-page__hero-award {
  opacity: 1;
  transform: translate(-50%, -50%) scale(1);
}

.project-page__header {
  margin-bottom: var(--s10);
}

.project-page__title {
  font-size: clamp(var(--t-2xl), 4vw, var(--t-4xl));
  font-weight: 400;
  letter-spacing: -0.02em;
  line-height: 1.15;
  margin: var(--s4) 0 var(--s2);
}

.project-page__year {
  font-size: var(--t-sm);
  color: var(--text-muted);
  margin: 0;
}

.project-page__body {
  display: grid;
  grid-template-columns: 1fr 260px;
  gap: var(--s12);
  align-items: start;
}

.project-page__desc {
  font-size: var(--t-lg);
  color: var(--text-sec);
  line-height: 1.75;
  margin-bottom: var(--s8);
}

.project-page__lead {
  font-size: 1.02em;
  color: var(--text);
  line-height: 1.75;
  letter-spacing: -0.01em;
  max-width: 780px;
  padding: var(--s4) 0 var(--s4) var(--s6);
  border-left: 2px solid var(--text);
  margin: 0 0 var(--s10);
}

.project-page__section-title {
  font-size: var(--t-xs);
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: var(--s3);
}

.project-page__detail-text {
  font-size: var(--t-base);
  color: var(--text-sec);
  line-height: 1.8;
  margin-bottom: var(--s6);
}

.project-page__content {
  max-width: 100%;
}

.project-img-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--s4);
  margin: var(--s8) 0;
}

.project-img-grid img,
.project-img-grid video {
  width: 100%;
  border-radius: var(--radius-lg);
  display: block;
}

@media (max-width: 600px) {
  .project-img-grid {
    grid-template-columns: 1fr;
  }
}

/* Two-column section: text on left, supporting image on right */
.project-page__two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--s10);
  align-items: center;
  margin: var(--s8) 0;
}

.project-page__two-col--start {
  align-items: start;
}

.project-page__two-col img,
.project-page__two-col video {
  width: 100%;
  border-radius: var(--radius-lg);
  display: block;
}

.project-page__two-col>div>p.project-page__detail-text:last-child {
  margin-bottom: 0;
}

.sentverse-device-gallery {
  grid-template-columns: repeat(3, minmax(0, 1fr));
  align-items: start;
}

.sentverse-device-gallery img {
  height: 260px;
  object-fit: cover;
}

@media (max-width: 900px) {
  .project-page__two-col {
    grid-template-columns: 1fr;
    gap: var(--s6);
  }

  .sentverse-device-gallery {
    grid-template-columns: 1fr;
  }

  .sentverse-device-gallery img {
    height: auto;
  }
}

.project-page__sidebar {
  padding-top: var(--s2);
}

.project-page__meta-block {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--s6) var(--s10);
  padding: var(--s6) 0;
  margin-bottom: var(--s10);
}

.project-page__meta-item {
  margin-bottom: 0;
}

.project-page__meta-label {
  font-size: var(--t-xs);
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: var(--s2);
}

.project-page__meta-value {
  font-size: var(--t-sm);
  color: var(--text-sec);
  line-height: 1.6;
}

.project-page__abstract {
  font-size: 1.02em;
  line-height: 1.75;
  padding: var(--s2) 0 var(--s2) var(--s8);
  border-left: 2px solid var(--text);
  color: var(--text);
}

.project-page__authors {
  font-size: var(--t-sm);
  color: var(--text-muted);
  margin-top: var(--s3);
  line-height: 1.6;
}

.project-page__prose {
  max-width: 660px;
  padding-top: var(--s10);
}


.project-page__nav-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--s8) 0;
  margin-top: var(--s16);
  border-top: 1px solid var(--border-light);
}

.project-page__nav-link {
  font-size: var(--t-sm);
  font-weight: 500;
  color: var(--text-sec);
  transition: color var(--ease);
}

.project-page__nav-link--next {
  margin-left: auto;
}

.project-page__nav-link:hover {
  color: var(--text);
}

/* Tags inside project detail pages — plain text, no pill */
.project-page__inner .tag {
  background: none;
  padding: 0;
  border-radius: 0;
  font-weight: 500;
  color: var(--text-sec);
  letter-spacing: 0;
}

.project-page__inner .tag+.tag::before {
  content: ' · ';
  color: var(--text-muted);
  margin: 0;
}


/* Playground page */
.playground-page__grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: var(--s6);
  margin-top: var(--s8);
}


/* ── 19. Responsive — Tablet (≤900px) ───────── */
@media (max-width: 900px) {
  :root {
    --sidebar-w: 240px;
  }

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

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

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

  .project-page__body {
    grid-template-columns: 1fr;
  }

  .project-page__sidebar {
    position: static;
  }

  .projects-timeline {
    max-width: 100%;
  }

  .timeline-item {
    padding-left: 120px;
  }

  .timeline-item__content {
    grid-template-columns: 160px 1fr;
  }

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


/* ── 20. Responsive — Mobile (≤700px) ───────── */
@media (max-width: 700px) {

  /* Hide desktop sidebar, show mobile nav */
  .sidebar {
    display: none;
  }

  .mobile-nav {
    display: flex;
  }

  .mobile-menu {
    display: flex;
  }

  .content {
    margin-left: 0;
    padding-top: var(--nav-h);
  }

  .content-section {
    padding: var(--s12) var(--s6);
  }

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

  .projects-grid--4 {
    grid-template-columns: repeat(2, 1fr);
    gap: var(--s3);
  }

  .award-item {
    grid-template-columns: 1fr;
    gap: var(--s2);
  }

  .projects-timeline {
    max-width: 100%;
    margin-left: 0;
  }

  .projects-timeline.grid-view {
    grid-template-columns: 1fr;
  }

  .projects-timeline::before {
    display: none;
  }

  .timeline-item {
    padding-left: 0;
    padding-bottom: var(--s8);
  }

  .timeline-item::before {
    display: none;
  }

  .timeline-item__date {
    position: static;
    display: block;
    margin-bottom: var(--s2);
  }

  .timeline-item__content {
    grid-template-columns: 1fr;
  }

  .project-page__inner {
    padding: 0 var(--s4);
  }

  .project-page__body {
    grid-template-columns: 1fr;
  }

  .project-page__meta-block {
    grid-template-columns: 1fr;
  }

  .pub-item {
    grid-template-columns: 1fr;
    gap: var(--s3);
  }
}


/* ── 21. Print ───────────────────────────────── */
@media print {

  .sidebar,
  .mobile-nav {
    display: none !important;
  }

  .content {
    margin-left: 0;
  }

  body {
    background: #fff;
  }
}