/* Fuji Wide 400–inspired palette: warm cream base, soft golden lift,
   muted sage/teal accents (typical Fuji consumer film shadow cast) */

:root {
  --bg: #f2e8dc;
  --bg-tint: #e6d9ca;
  /* Outer frame: slightly deeper warm greige, same family as --bg / --bg-tint */
  --bg-frame: #d4c8b6;
  --ink: #2c2824;
  --muted: #72685f;
  --accent: #455c52;
  --accent-hover: #384942;
  --accent-soft: rgba(69, 92, 82, 0.14);
  --accent-line: rgba(69, 92, 82, 0.32);
  --border: rgba(44, 40, 36, 0.11);
  --shadow-ink: rgba(44, 40, 36, 0.09);
  --shadow-card: 0 12px 40px rgba(44, 40, 36, 0.07);
  --surface: #faf6f0;
  --radius: 12px;
  --font-sans: "DM Sans", system-ui, sans-serif;
  --font-serif: "Source Serif 4", Georgia, serif;
  --space: clamp(0.3rem, 1vw, 0.65rem);
  /* Horizontal inset inside the cream column: line + text align; column stays wider */
  --page-inline-pad: clamp(1.15rem, 3.25vw, 2.35rem);
  /* Extra horizontal inset so text is narrower while --max column stays fixed */
  --content-inset: clamp(1.2rem, 5.25vw, 3.25rem);
  /* Main content column width (header/footer align to this) */
  --max: 68rem;
  /* Type scale — one size per role */
  --text-base: 1.05rem;
  --text-sm: 0.9375rem;
  --text-label: 0.8125rem;
  --text-hero: clamp(2.1rem, 4.5vw, 3.15rem);
  --text-page-h2: clamp(1.65rem, 2.5vw, 2rem);
  --text-card-title: 1.125rem;
  --text-name: clamp(1.35rem, 2.8vw, 1.85rem);
  /* Space above / below the divider between About and Research Projects */
  --section-about-projects-gap: clamp(1.85rem, 3.75vw, 2.65rem);
}

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

/* Zpix (最像素) — Chinese pixel font; https://github.com/SolidZORO/zpix-pixel-font */
@font-face {
  font-family: Zpix;
  src: url("https://cdn.jsdelivr.net/gh/SolidZORO/zpix-pixel-font@v3.1.11/dist/zpix.ttf")
    format("truetype");
  font-display: swap;
}

html {
  scroll-behavior: smooth;
  isolation: isolate;
  background-color: var(--bg-frame);
}

body {
  margin: 0;
  padding-inline: clamp(0.85rem, 4.5vw, 2.85rem);
  font-family: var(--font-sans);
  font-size: var(--text-base);
  line-height: 1.65;
  color: var(--ink);
  background: var(--bg-frame);
  font-optical-sizing: auto;
}

main#main {
  max-width: var(--max);
  width: 100%;
  margin-left: auto;
  margin-right: auto;
  background: var(--bg);
  padding: 0 calc(var(--page-inline-pad) + var(--content-inset));
}

main,
.site-footer {
  position: relative;
}

@media (max-width: 720px) {
  main#main,
  .site-header,
  .site-footer {
    max-width: min(var(--max), 100%);
  }
}

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

.skip-link {
  position: absolute;
  left: -9999px;
  z-index: 999;
  padding: 0.5rem 1rem;
  background: var(--accent);
  color: #fff;
  text-decoration: none;
  border-radius: 4px;
}

.skip-link:focus {
  left: 1rem;
  top: 1rem;
}

/* Header */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  max-width: var(--max);
  width: 100%;
  margin-left: auto;
  margin-right: auto;
  padding: 0 calc(var(--page-inline-pad) + var(--content-inset));
  background: var(--bg);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  position: relative;
  width: 100%;
  margin: 0;
  padding: 0.85rem 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.logo {
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--ink);
  text-decoration: none;
  font-size: var(--text-base);
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 1.35rem;
}

.site-nav a {
  color: var(--muted);
  text-decoration: none;
  font-size: var(--text-sm);
  font-weight: 500;
}

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

.nav-toggle {
  display: none;
  background: none;
  border: none;
  padding: 0.35rem;
  cursor: pointer;
}

.nav-toggle-bar {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--ink);
  box-shadow: 0 6px 0 var(--ink), 0 -6px 0 var(--ink);
}

@media (max-width: 720px) {
  .nav-toggle {
    display: block;
  }

  .site-nav {
    display: none;
    position: absolute;
    right: var(--space);
    top: 100%;
    flex-direction: column;
    align-items: flex-start;
    padding: 1rem 1.25rem;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.08);
  }

  .site-nav.is-open {
    display: flex;
  }
}

/* Hero */

.hero {
  padding: clamp(1.75rem, 4.5vw, 3rem) 0;
  display: grid;
  gap: 2.5rem;
  grid-template-columns: 1fr;
}

@media (min-width: 880px) {
  .hero {
    grid-template-columns: 1.15fr 1fr;
    align-items: stretch;
  }
}

.hero-kicker {
  font-size: clamp(0.625rem, 0.48rem + 1.55vw, var(--text-label));
  font-weight: 600;
  letter-spacing: 0.075em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 0.75rem;
}

@media (max-width: 420px) {
  .hero-kicker {
    font-size: clamp(0.5625rem, 2.85vw + 0.32rem, 0.75rem);
    letter-spacing: 0.065em;
  }
}

.hero h1 {
  font-family: var(--font-serif);
  font-size: var(--text-hero);
  font-weight: 700;
  line-height: 1.12;
  letter-spacing: -0.03em;
  margin: 0 0 1rem;
}

.hero-lead {
  margin: 0 0 1.75rem;
  color: var(--muted);
  max-width: 44rem;
  font-size: var(--text-base);
}

/* Match site prose links; UA default blue/underline clashes with palette + serif/sans rhythm */
.hero-lead a {
  color: var(--accent);
  font-weight: inherit;
  text-decoration: none;
  border-bottom: 1px solid var(--accent-line);
  transition: border-color 0.15s ease, color 0.15s ease;
}

.hero-lead a:hover {
  border-bottom-color: var(--accent);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.65rem 1.25rem;
  border-radius: 999px;
  font-weight: 600;
  font-size: var(--text-sm);
  text-decoration: none;
  border: 1px solid transparent;
  transition: background 0.15s ease, color 0.15s ease, border-color 0.15s ease;
}

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

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

.btn-ghost {
  background: transparent;
  color: var(--accent);
  border-color: var(--accent-line);
}

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

.hero-aside {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.15rem;
  background: var(--surface);
  box-shadow: 0 1px 0 rgba(255, 252, 247, 0.85) inset;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
}

#contact.hero-aside {
  scroll-margin-top: 5rem;
}

.hero-photo-wrap {
  margin: 0 auto 1.25rem;
  padding: 0;
  width: 100%;
  max-width: min(100%, 420px);
  aspect-ratio: 4 / 5;
  overflow: hidden;
  border-radius: calc(var(--radius) + 6px);
  border: 1px solid var(--border);
  box-shadow: 0 12px 36px var(--shadow-ink);
  flex-shrink: 0;
}

.hero-photo {
  display: block;
  width: 100%;
  height: 100%;
  margin: 0;
  object-fit: cover;
  /* Crop left edge (other guest), trim sky; tune % if framing feels off */
  object-position: 62% 34%;
}

.hero-name {
  margin: 0 0 0.35rem;
  font-family: var(--font-serif);
  font-size: var(--text-name);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.25;
  color: var(--ink);
  text-align: center;
}

/* Chinese name — smaller than English; Noto Sans SC reads clearly at small sizes */
.hero-name--zh {
  margin-top: 0.15rem;
  margin-bottom: 0.4rem;
  font-family: "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei",
    "Source Han Sans SC", sans-serif;
  font-size: clamp(0.72rem, 1.80vw, 0.95rem);
  font-weight: 500;
  letter-spacing: 0.04em;
  line-height: 1.4;
}

.hero-byline {
  margin: 0 0 0.85rem;
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--muted);
  line-height: 1.45;
  text-align: center;
}

.hero-social {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.hero-social-link {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2rem;
  height: 2rem;
  border-radius: var(--radius);
  color: var(--accent);
  background: var(--accent-soft);
  border: 1px solid transparent;
  transition: background 0.15s ease, color 0.15s ease, border-color 0.15s ease,
    transform 0.15s ease;
}

.hero-social-link::after {
  content: attr(data-tooltip);
  position: absolute;
  bottom: calc(100% + 0.45rem);
  left: 50%;
  z-index: 70;
  padding: 0.38rem 0.65rem;
  font-family: var(--font-sans);
  font-size: var(--text-label);
  font-weight: 600;
  line-height: 1.2;
  color: var(--ink);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  box-shadow: var(--shadow-card);
  white-space: nowrap;
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transform: translateX(-50%) translateY(4px);
  transition: opacity 0.18s ease, transform 0.18s ease, visibility 0.18s;
}

.hero-social-link:hover::after,
.hero-social-link:focus-visible::after {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(0);
}

@media (prefers-reduced-motion: reduce) {
  .hero-social-link::after {
    transition: opacity 0.12s ease, visibility 0.12s;
    transform: translateX(-50%);
  }

  .hero-social-link:hover::after,
  .hero-social-link:focus-visible::after {
    transform: translateX(-50%);
  }
}

button.hero-social-link {
  cursor: pointer;
  font: inherit;
  padding: 0;
}

.hero-social-link:hover {
  background: var(--accent);
  color: var(--surface);
  border-color: var(--accent);
  transform: translateY(-1px);
}

.hero-social-icon {
  width: 1.05rem;
  height: 1.05rem;
  display: block;
}

.hero-social-icon--line {
  fill: none;
  stroke: currentColor;
  stroke-width: 2.2;
}

/* Mortarboard outline reads smaller than filled icons at equal box size */
.hero-social-icon--scholar {
  width: 1.2rem;
  height: 1.2rem;
}

/* Toast when email is copied to clipboard */
.email-copy-toast {
  position: fixed;
  bottom: 1.35rem;
  left: 50%;
  z-index: 400;
  max-width: min(90vw, 22rem);
  padding: 0.65rem 1.15rem;
  font-family: var(--font-sans);
  font-size: var(--text-sm);
  font-weight: 600;
  text-align: center;
  color: #fff;
  background: var(--accent);
  border-radius: 999px;
  box-shadow: var(--shadow-card);
  opacity: 0;
  transform: translate3d(-50%, 0.5rem, 0);
  pointer-events: none;
  transition: opacity 0.22s ease, transform 0.22s ease;
}

.email-copy-toast.email-copy-toast--visible {
  opacity: 1;
  transform: translate3d(-50%, 0, 0);
}

@media (prefers-reduced-motion: reduce) {
  .email-copy-toast {
    transition: none;
  }
}

/* About block + Path directly underneath */

.about-stack .hero {
  padding-top: clamp(1.5rem, 4vw, 2.5rem);
  padding-bottom: var(--section-about-projects-gap);
}

.about-stack .hero > .path-below {
  grid-column: 1 / -1;
}

.about-stack .hero .hero-grid {
  grid-column: 1 / -1;
  display: grid;
  gap: 2rem;
  align-items: start;
}

/* Bio column: wide enough for long lines (e.g. links), still a comfortable measure */
.about-stack {
  /* Reserve space for kicker + h1 so .hero-lead starts at the same Y in day vs night (tight fit + small buffer) */
  --hero-heading-slot-min: clamp(5.85rem, 15.5vw, 6.9rem);
}

.about-stack .hero-copy {
  max-width: min(40rem, 100%);
}

.about-stack .hero-heading {
  display: flex;
  flex-direction: column;
  justify-content: flex-start;
  min-height: var(--hero-heading-slot-min);
  box-sizing: border-box;
}

.about-stack .hero h1 {
  margin-bottom: 0.65rem;
}

.about-stack .hero-copy .hero-lead {
  line-height: 1.72;
}

.about-stack .hero-copy .hero-lead + .hero-lead {
  margin-top: 1.05em;
}

.about-stack .hero-copy .hero-lead:not(:last-child) {
  margin-bottom: 0;
}

/* Profile card: compact height (about section only) */
.about-stack .hero-aside {
  width: fit-content;
  max-width: 100%;
  margin-inline: auto;
  padding: 1rem 1.1rem;
}

.about-stack .hero-aside .hero-photo-wrap {
  margin-top: 0.35rem;
  margin-bottom: 1rem;
  /* Shorter than default 4/5 portrait */
  aspect-ratio: 3 / 4;
}

.about-stack .hero-aside .hero-byline {
  margin-bottom: 0.65rem;
}

@media (min-width: 880px) {
  .about-stack .hero .hero-grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr);
    gap: 2.5rem;
    /* Row height = taller column; bio column centers its block against the profile card */
    align-items: stretch;
  }

  .about-stack .hero-copy {
    display: flex;
    flex-direction: column;
    justify-content: center;
    min-height: 0;
  }

  .about-stack .hero-copy .hero-lead {
    max-width: none;
    margin-bottom: 0;
  }

  .about-stack .hero-aside {
    justify-self: center;
    align-self: start;
  }

  .about-stack .hero-aside .hero-photo-wrap {
    max-width: min(100%, 270px);
  }
}

.path-below {
  padding: clamp(1rem, 2.5vw, 1.5rem) 0 clamp(1.75rem, 4vw, 2.5rem);
  border-top: 1px solid var(--border);
}

.path-below .section-head {
  margin-bottom: 1.35rem;
}

/* Match main column width; global .section-deck is capped at 42rem */
.path-below .section-deck {
  max-width: none;
}

/* Sections */

.section {
  padding: clamp(1.25rem, 3.5vw, 2.25rem) 0;
}

#projects.section {
  border-top: 1px solid var(--border);
  padding-top: var(--section-about-projects-gap);
}

.section-tint {
  background: var(--bg-tint);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.section-head {
  display: flex;
  flex-direction: column;
  justify-content: flex-start;
  /* Stable slot so Research body copy lines up when theme swaps heading font */
  min-height: clamp(3.05rem, 9vw, 4rem);
  margin-bottom: 1.75rem;
  box-sizing: border-box;
}

.section-head h2 {
  font-family: var(--font-serif);
  font-size: var(--text-page-h2);
  margin: 0 0 0.5rem;
  letter-spacing: -0.02em;
}

.section-deck {
  margin: 0;
  max-width: 48rem;
  color: var(--muted);
  font-size: var(--text-base);
}

.prose {
  max-width: 48rem;
}

.prose p {
  margin: 0;
}

/* Path — horizontal timeline (left → right, older → newer) */

.path-wrap {
  max-width: none;
}

.timeline-h {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  grid-template-rows: 1fr 1fr;
  gap: 0 1.25rem;
  position: relative;
  min-height: min(22rem, 70vw);
}

/* Full-width rail; nodes sit on the line, not at the line’s ends */
.timeline-h::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 50%;
  transform: translateY(-50%);
  height: 2px;
  background: var(--border);
  z-index: 0;
}

.timeline-h-item {
  position: relative;
  z-index: 1;
  margin: 0;
  padding: 0;
  min-width: 0;
}

.timeline-h-item--above {
  grid-row: 1;
  align-self: end;
}

.timeline-h-item--below {
  grid-row: 2;
  align-self: start;
}

.timeline-h-link {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  margin: 0;
  padding: 0.5rem 0.35rem;
  text-decoration: none;
  color: inherit;
  border-radius: var(--radius);
  outline-offset: 2px;
  transition: background 0.2s ease;
  position: relative;
}

.timeline-h-item--above .timeline-h-link {
  padding-bottom: 1.35rem;
}

.timeline-h-item--below .timeline-h-link {
  padding-top: 1.35rem;
}

.timeline-h-link:hover,
.timeline-h-link:focus-visible {
  background: rgba(69, 92, 82, 0.06);
}

.timeline-h-dot {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid var(--bg);
  box-shadow: 0 0 0 1px var(--border);
  flex-shrink: 0;
}

.timeline-h-item--above .timeline-h-dot {
  position: absolute;
  left: 50%;
  bottom: 0;
  transform: translate(-50%, 50%);
  margin: 0;
}

.timeline-h-item--below .timeline-h-dot {
  position: absolute;
  left: 50%;
  top: 0;
  transform: translate(-50%, -50%);
  margin: 0;
}

.timeline-h-time {
  font-size: var(--text-label);
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.35rem;
}

.timeline-h-title {
  font-family: var(--font-serif);
  font-size: var(--text-card-title);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.25;
  color: var(--ink);
  margin-bottom: 0.5rem;
}

.timeline-h-text {
  margin: 0;
  font-size: var(--text-base);
  line-height: 1.55;
  color: var(--muted);
}

.timeline-h-item--below .timeline-h-time {
  margin-top: 0.15rem;
}

@media (max-width: 720px) {
  .timeline-h {
    grid-template-columns: 1fr;
    grid-template-rows: none;
    gap: 0;
    min-height: 0;
    padding-left: 0.35rem;
    border-left: 2px solid var(--border);
  }

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

  .timeline-h-item--above,
  .timeline-h-item--below {
    grid-row: auto;
    align-self: stretch;
  }

  .timeline-h-item:not(:last-child) .timeline-h-link {
    padding-bottom: 1.25rem;
    margin-bottom: 0.25rem;
    border-bottom: 1px solid var(--border);
  }

  .timeline-h-link {
    align-items: flex-start;
    text-align: left;
    padding-left: 1rem;
    padding-top: 0.5rem;
    padding-bottom: 0.5rem;
  }

  .timeline-h-item--above .timeline-h-link,
  .timeline-h-item--below .timeline-h-link {
    padding-top: 0.5rem;
    padding-bottom: 0.5rem;
  }

  .timeline-h-item--above .timeline-h-dot,
  .timeline-h-item--below .timeline-h-dot {
    position: absolute;
    left: calc(-0.35rem - 7px);
    top: 0.55rem;
    bottom: auto;
    transform: none;
  }
}

/* Projects — vertical timeline: year + dot nodes on the left, spine through dots */

.projects-timeline {
  --pt-node-w: 4rem;
  --pt-node-gap: 1.1rem;
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

/* Spine aligned to horizontal center of node column */
.projects-timeline::before {
  content: "";
  position: absolute;
  z-index: 0;
  left: calc(var(--pt-node-w) / 2);
  transform: translateX(-50%);
  top: 0.55rem;
  bottom: 0.55rem;
  width: 2px;
  background: var(--border);
}

.project-timeline-row {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: var(--pt-node-w) minmax(0, 1fr);
  column-gap: var(--pt-node-gap);
  align-items: start;
}

.project-timeline-node {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.4rem;
  padding-top: 0.15rem;
  text-align: center;
}

.project-year {
  display: block;
  margin: 0;
  font-size: var(--text-label);
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--accent);
  line-height: 1.2;
  max-width: var(--pt-node-w);
  font-variant-numeric: tabular-nums;
}

.project-timeline-dot {
  width: 13px;
  height: 13px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid var(--bg);
  box-shadow: 0 0 0 1px var(--border);
  flex-shrink: 0;
  position: relative;
  z-index: 1;
}

@media (max-width: 480px) {
  .projects-timeline {
    --pt-node-w: 3.35rem;
    --pt-node-gap: 0.85rem;
  }
}

.project-card {
  scroll-margin-top: 5rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: calc(var(--radius) + 4px);
  padding: 1.35rem 1.25rem;
  box-shadow: var(--shadow-card);
  display: flex;
  flex-direction: column;
  min-height: 0;
}

.project-kicker {
  margin: 0 0 0.5rem;
  font-size: var(--text-label);
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}

.project-card h3 {
  font-family: var(--font-serif);
  font-size: var(--text-card-title);
  margin: 0 0 0.35rem;
  letter-spacing: -0.02em;
  line-height: 1.3;
}

.project-authors {
  margin: 0 0 0.5rem;
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--muted);
  line-height: 1.45;
}

.project-authors strong {
  font-weight: 600;
  color: var(--ink);
}

.project-authors a {
  color: var(--accent);
  font-weight: inherit;
  text-decoration: none;
  border-bottom: 1px solid var(--accent-line);
}

.project-authors a:hover {
  border-bottom-color: var(--accent);
}

.project-title-follow {
  margin: 0 0 0.65rem;
  font-size: var(--text-sm);
  font-weight: 600;
}

.project-title-follow a {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid var(--accent-line);
}

.project-title-follow a:hover {
  border-bottom-color: var(--accent);
}

.project-title-follow-sep {
  margin: 0 0.4rem;
  color: var(--muted);
  font-weight: 400;
}

.project-summary {
  margin: 0;
  flex: 1;
  color: var(--muted);
  font-size: var(--text-base);
  line-height: 1.55;
}

.project-summary a {
  color: var(--accent);
  font-weight: 600;
  text-decoration: none;
  border-bottom: 1px solid var(--accent-line);
}

.project-summary a:hover {
  border-bottom-color: var(--accent);
}

/* Poster modal */

.modal {
  position: fixed;
  inset: 0;
  z-index: 300;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space);
}

.modal[hidden] {
  display: none;
}

.modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(44, 40, 36, 0.45);
  backdrop-filter: blur(4px);
}

.modal-panel {
  position: relative;
  z-index: 1;
  width: min(920px, 100%);
  max-height: min(92vh, 900px);
  display: flex;
  flex-direction: column;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: calc(var(--radius) + 6px);
  box-shadow: var(--shadow-card);
  overflow: hidden;
}

.modal-chrome {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.65rem 1rem;
  border-bottom: 1px solid var(--border);
  background: var(--bg-tint);
}

.modal-title {
  margin: 0;
  font-family: var(--font-serif);
  font-size: var(--text-card-title);
  font-weight: 700;
}

.modal-close {
  flex-shrink: 0;
  width: 2.25rem;
  height: 2.25rem;
  border: none;
  border-radius: var(--radius);
  background: transparent;
  color: var(--ink);
  font-size: 1.5rem;
  line-height: 1;
  cursor: pointer;
  transition: background 0.15s ease;
}

.modal-close:hover {
  background: var(--accent-soft);
}

.modal-frame-wrap {
  flex: 1;
  min-height: 0;
  background: var(--bg-tint);
}

.modal-pdf-frame {
  display: block;
  width: 100%;
  height: min(72vh, 720px);
  min-height: 320px;
  border: 0;
}

/* Themes */

.theme-grid {
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}

.theme-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.35rem 1.25rem;
}

.theme-card h3 {
  margin: 0 0 0.5rem;
  font-size: var(--text-card-title);
  font-weight: 700;
}

.theme-card p {
  margin: 0;
  color: var(--muted);
  font-size: var(--text-base);
}

/* Footer */

.site-footer {
  padding: 1.15rem calc(var(--page-inline-pad) + var(--content-inset)) 2rem;
  border-top: 1px solid var(--border);
  max-width: var(--max);
  width: 100%;
  margin-left: auto;
  margin-right: auto;
  background: var(--bg);
}

.site-footer p {
  margin: 0;
  font-size: var(--text-sm);
  color: var(--muted);
  line-height: 1.55;
  max-width: min(48rem, 100%);
}

.site-footer a {
  color: var(--accent);
  font-weight: 600;
  text-decoration: underline;
  text-decoration-color: var(--accent-line);
  text-underline-offset: 0.15em;
}

.site-footer a:hover {
  text-decoration-color: var(--accent);
}

.site-footer code {
  font-size: 0.85em;
  background: var(--accent-soft);
  padding: 0.1em 0.35em;
  border-radius: 4px;
}

/* Night / Nyan Cat–inspired theme toggle + bubbles */

.theme-night-toggle {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.45rem;
  height: 2.45rem;
  padding: 0;
  flex-shrink: 0;
  font: inherit;
  cursor: pointer;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--surface);
  color: var(--muted);
  overflow: visible;
  transition: background 0.15s ease, color 0.15s ease, border-color 0.15s ease,
    box-shadow 0.15s ease;
}

.theme-night-toggle:hover {
  color: var(--accent);
  border-color: var(--accent-line);
  background: var(--accent-soft);
}

.theme-night-toggle[aria-pressed="true"] {
  color: var(--accent);
  border-color: var(--accent);
  background: var(--accent-soft);
}

.theme-night-toggle__icon {
  display: block;
  flex-shrink: 0;
}

.theme-night-toggle__icon--sun {
  display: none;
}

.theme-night-toggle[aria-pressed="true"] .theme-night-toggle__icon--moon {
  display: none;
}

.theme-night-toggle[aria-pressed="true"] .theme-night-toggle__icon--sun {
  display: block;
}

/* Day theme only: tight rainbow rim on moon toggle — soft “leak” without a wide glow */
body:not(.theme-nyan) .theme-night-toggle[aria-pressed="false"] {
  isolation: isolate;
}

body:not(.theme-nyan) .theme-night-toggle[aria-pressed="false"]::before {
  content: "";
  position: absolute;
  inset: -4px;
  border-radius: 50%;
  z-index: -1;
  pointer-events: none;
  background: conic-gradient(
    from 210deg,
    #ff4d8d,
    #ffb020,
    #fff176,
    #69f0ae,
    #40c4ff,
    #b388ff,
    #ff4d8d
  );
  filter: blur(1.5px);
  opacity: 0.38;
  transform-origin: 50% 50%;
  animation: theme-night-toggle-otherworld-gleam 4.8s ease-in-out infinite;
  -webkit-mask-image: radial-gradient(
    farthest-side,
    transparent calc(100% - 6px),
    #000 calc(100% - 5px),
    #000 calc(100% - 3px),
    transparent 100%
  );
  mask-image: radial-gradient(
    farthest-side,
    transparent calc(100% - 6px),
    #000 calc(100% - 5px),
    #000 calc(100% - 3px),
    transparent 100%
  );
}

@keyframes theme-night-toggle-otherworld-gleam {
  0% {
    opacity: 0.26;
    transform: rotate(0deg) scale(1);
    filter: blur(1px);
  }
  35% {
    opacity: 0.52;
    transform: rotate(128deg) scale(1.022);
    filter: blur(1.75px);
  }
  70% {
    opacity: 0.32;
    transform: rotate(260deg) scale(1.012);
    filter: blur(1.35px);
  }
  100% {
    opacity: 0.26;
    transform: rotate(360deg) scale(1);
    filter: blur(1px);
  }
}

@media (prefers-reduced-motion: reduce) {
  body:not(.theme-nyan) .theme-night-toggle[aria-pressed="false"]::before {
    animation: none;
    opacity: 0.34;
    transform: none;
    filter: blur(1.25px);
  }
}

.nyan-bubbles {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  overflow: hidden;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.45s ease, visibility 0.45s ease;
}

body.theme-nyan .nyan-bubbles {
  opacity: 1;
  visibility: visible;
}

.nyan-balloon-cats,
.nyan-pixel-bubbles {
  position: absolute;
  inset: 0;
  pointer-events: none;
}

.nyan-balloon-cat {
  position: absolute;
  bottom: -22%;
  left: var(--bc-x, 12%);
  width: var(--bc-w, 64px);
  height: auto;
  max-width: min(var(--bc-w, 64px), 22vw);
  image-rendering: pixelated;
  image-rendering: crisp-edges;
  -ms-interpolation-mode: nearest-neighbor;
  opacity: 0.9;
  animation: nyan-balloon-rise var(--bc-dur, 22s) linear infinite;
  animation-delay: var(--bc-delay, 0s);
  filter: drop-shadow(0 3px 0 rgba(0, 0, 0, 0.4))
    drop-shadow(0 0 14px rgba(255, 120, 200, 0.35));
}

.nyan-balloon-cat:nth-child(1) {
  --bc-x: 6%;
  --bc-w: 72px;
  --bc-dur: 26s;
  --bc-delay: -3s;
  --bc-drift: 36px;
}

.nyan-balloon-cat:nth-child(2) {
  --bc-x: 52%;
  --bc-w: 56px;
  --bc-dur: 21s;
  --bc-delay: -9s;
  --bc-drift: -28px;
}

.nyan-balloon-cat:nth-child(3) {
  --bc-x: 88%;
  --bc-w: 64px;
  --bc-dur: 24s;
  --bc-delay: -17s;
  --bc-drift: 22px;
}

/* Right gutter: mirrored, smaller; invisible until ~80% of cycle, then rises (matches left balloon’s 26s period) */
.nyan-balloon-cat--frame-right {
  display: none;
  left: auto;
  right: max(0.5rem, calc((100vw - var(--max)) / 2 + 0.35rem));
  --bc-w: 50px;
  --bc-dur: 26s;
  --bc-drift: -26px;
  animation: nyan-balloon-rise-frame-right var(--bc-dur, 26s) linear infinite;
  transform-origin: 50% 100%;
}

@media (min-width: 73rem) {
  .nyan-balloon-cat--frame-right {
    display: block;
  }
}

@keyframes nyan-balloon-rise-frame-right {
  0%,
  80% {
    transform: translate3d(0, 0, 0) rotate(3deg) scaleX(-1);
    opacity: 0;
  }
  81% {
    opacity: 0.95;
  }
  88% {
    opacity: 0.55;
  }
  100% {
    transform: translate3d(var(--bc-drift, -26px), -128vh, 0) rotate(-2deg) scaleX(-1);
    opacity: 0;
  }
}

@keyframes nyan-balloon-rise {
  0% {
    transform: translate3d(0, 0, 0) rotate(-3deg);
    opacity: 0.88;
  }
  12% {
    opacity: 0.95;
  }
  88% {
    opacity: 0.55;
  }
  100% {
    transform: translate3d(var(--bc-drift, 24px), -128vh, 0) rotate(2deg);
    opacity: 0;
  }
}

.nyan-pixel-bubbles .nyan-bubble {
  position: absolute;
  bottom: -15%;
  left: var(--bx, 10%);
  width: var(--bs, 36px);
  height: var(--bs, 36px);
  display: grid;
  place-items: center;
  background: transparent;
  border-radius: 0;
  box-shadow: none;
  animation: nyan-bubble-rise var(--bd, 14s) linear infinite;
  animation-delay: var(--bdelay, 0s);
  opacity: 0.92;
}

.nyan-bubble-core {
  display: block;
  width: 58%;
  height: 58%;
  min-width: 8px;
  min-height: 8px;
  border-radius: 0;
  box-shadow:
    0 0 0 1px rgba(255, 255, 255, 0.5),
    3px 3px 0 0 rgba(0, 0, 0, 0.45);
  animation: nyan-pixel-morph var(--bm, 0.95s) linear infinite;
  animation-delay: var(--bm-delay, 0s);
}

.nyan-pixel-bubbles .nyan-bubble:nth-child(even) .nyan-bubble-core {
  animation-direction: reverse;
}

.nyan-pixel-bubbles .nyan-bubble:nth-child(1) {
  --bx: 8%;
  --bs: 28px;
  --bd: 11s;
  --bdelay: 0s;
  --bm: 0.82s;
  --bm-delay: 0s;
}
.nyan-pixel-bubbles .nyan-bubble:nth-child(2) {
  --bx: 18%;
  --bs: 44px;
  --bd: 16s;
  --bdelay: -2s;
  --bm: 1.05s;
  --bm-delay: -0.2s;
}
.nyan-pixel-bubbles .nyan-bubble:nth-child(3) {
  --bx: 28%;
  --bs: 22px;
  --bd: 13s;
  --bdelay: -4s;
  --bm: 0.74s;
  --bm-delay: -0.5s;
}
.nyan-pixel-bubbles .nyan-bubble:nth-child(4) {
  --bx: 38%;
  --bs: 52px;
  --bd: 18s;
  --bdelay: -1s;
  --bm: 1.12s;
  --bm-delay: -0.35s;
}
.nyan-pixel-bubbles .nyan-bubble:nth-child(5) {
  --bx: 48%;
  --bs: 34px;
  --bd: 12s;
  --bdelay: -6s;
  --bm: 0.88s;
  --bm-delay: -0.65s;
}
.nyan-pixel-bubbles .nyan-bubble:nth-child(6) {
  --bx: 58%;
  --bs: 26px;
  --bd: 15s;
  --bdelay: -3s;
  --bm: 0.96s;
  --bm-delay: -0.1s;
}
.nyan-pixel-bubbles .nyan-bubble:nth-child(7) {
  --bx: 68%;
  --bs: 40px;
  --bd: 14s;
  --bdelay: -7s;
  --bm: 0.78s;
  --bm-delay: -0.4s;
}
.nyan-pixel-bubbles .nyan-bubble:nth-child(8) {
  --bx: 78%;
  --bs: 30px;
  --bd: 17s;
  --bdelay: -5s;
  --bm: 1.08s;
  --bm-delay: -0.55s;
}
.nyan-pixel-bubbles .nyan-bubble:nth-child(9) {
  --bx: 88%;
  --bs: 48px;
  --bd: 19s;
  --bdelay: -2.5s;
  --bm: 0.9s;
  --bm-delay: -0.25s;
}
.nyan-pixel-bubbles .nyan-bubble:nth-child(10) {
  --bx: 12%;
  --bs: 36px;
  --bd: 14.5s;
  --bdelay: -8s;
  --bm: 1s;
  --bm-delay: -0.7s;
}
.nyan-pixel-bubbles .nyan-bubble:nth-child(11) {
  --bx: 35%;
  --bs: 24px;
  --bd: 11.5s;
  --bdelay: -9s;
  --bm: 0.72s;
  --bm-delay: -0.15s;
}
.nyan-pixel-bubbles .nyan-bubble:nth-child(12) {
  --bx: 55%;
  --bs: 42px;
  --bd: 16.5s;
  --bdelay: -4.5s;
  --bm: 1.15s;
  --bm-delay: -0.45s;
}
.nyan-pixel-bubbles .nyan-bubble:nth-child(13) {
  --bx: 72%;
  --bs: 20px;
  --bd: 10s;
  --bdelay: -1.2s;
  --bm: 0.68s;
  --bm-delay: -0.3s;
}
.nyan-pixel-bubbles .nyan-bubble:nth-child(14) {
  --bx: 92%;
  --bs: 38px;
  --bd: 15.5s;
  --bdelay: -6.5s;
  --bm: 0.92s;
  --bm-delay: -0.6s;
}
.nyan-pixel-bubbles .nyan-bubble:nth-child(15) {
  --bx: 22%;
  --bs: 32px;
  --bd: 13.5s;
  --bdelay: -10s;
  --bm: 0.86s;
  --bm-delay: -0.05s;
}
.nyan-pixel-bubbles .nyan-bubble:nth-child(16) {
  --bx: 62%;
  --bs: 46px;
  --bd: 17.5s;
  --bdelay: -3.2s;
  --bm: 1.02s;
  --bm-delay: -0.5s;
}
.nyan-pixel-bubbles .nyan-bubble:nth-child(17) {
  --bx: 42%;
  --bs: 28px;
  --bd: 12.5s;
  --bdelay: -7.5s;
  --bm: 0.8s;
  --bm-delay: -0.22s;
}
.nyan-pixel-bubbles .nyan-bubble:nth-child(18) {
  --bx: 85%;
  --bs: 34px;
  --bd: 14.2s;
  --bdelay: -5.8s;
  --bm: 0.98s;
  --bm-delay: -0.38s;
}

@keyframes nyan-pixel-morph {
  0%,
  22% {
    clip-path: polygon(0 0, 100% 0, 100% 100%, 0 100%);
    background-color: #5efff0;
    transform: rotate(0deg) scale(1);
  }
  24%,
  46% {
    clip-path: polygon(18% 0, 100% 0, 82% 100%, 0 100%);
    background-color: #ff6bcd;
    transform: rotate(90deg) scale(1.12, 0.88);
  }
  48%,
  70% {
    clip-path: polygon(0 12%, 88% 0, 100% 88%, 12% 100%);
    background-color: #fff15e;
    transform: rotate(180deg) scale(0.9, 1.1);
  }
  72%,
  94% {
    clip-path: polygon(50% 0, 100% 42%, 50% 100%, 0 42%);
    background-color: #9dff6b;
    transform: rotate(270deg) scale(1.05);
  }
  96%,
  100% {
    clip-path: polygon(0 0, 100% 0, 100% 100%, 0 100%);
    background-color: #5efff0;
    transform: rotate(360deg) scale(1);
  }
}

@keyframes nyan-bubble-rise {
  0% {
    transform: translate3d(0, 0, 0) scale(1);
    opacity: 0.75;
  }
  15% {
    opacity: 0.9;
  }
  85% {
    opacity: 0.55;
  }
  100% {
    transform: translate3d(var(--bx-drift, 18px), -125vh, 0) scale(1.08);
    opacity: 0;
  }
}

.nyan-pixel-bubbles .nyan-bubble:nth-child(odd) {
  --bx-drift: 22px;
}
.nyan-pixel-bubbles .nyan-bubble:nth-child(3n) {
  --bx-drift: -16px;
}
.nyan-pixel-bubbles .nyan-bubble:nth-child(3n + 1) {
  --bx-drift: 12px;
}

@media (prefers-reduced-motion: reduce) {
  .nyan-pixel-bubbles .nyan-bubble {
    animation: none;
    opacity: 0.25;
    bottom: 10%;
  }

  .nyan-bubble-core {
    animation: none;
    clip-path: polygon(0 0, 100% 0, 100% 100%, 0 100%);
    transform: none;
  }

  .nyan-balloon-cat {
    animation: none;
    bottom: 8%;
    opacity: 0.35;
  }

  .nyan-balloon-cat--frame-right {
    transform: translate3d(0, 0, 0) scaleX(-1);
    right: max(0.5rem, calc((100vw - var(--max)) / 2 + 0.35rem));
  }
}

/* Nyan / balloon night palette — inspired by nyan.cat balloon aesthetic */

body.theme-nyan {
  --bg: rgba(26, 10, 46, 0.92);
  --bg-tint: #2d1b52;
  --bg-frame: #0a0414;
  --ink: #f7f4ff;
  --muted: #d8d0ee;
  --accent: #ff6bcb;
  --accent-hover: #ff94d4;
  --accent-soft: rgba(255, 107, 203, 0.18);
  --accent-line: rgba(255, 150, 220, 0.55);
  --border: rgba(168, 130, 255, 0.35);
  --shadow-ink: rgba(0, 0, 0, 0.35);
  --shadow-card: 0 12px 40px rgba(0, 0, 0, 0.35);
  --surface: rgba(45, 27, 82, 0.88);
  --font-sans: "DM Sans", system-ui, sans-serif;
  /* Match day heading/body metrics; section h2 uses Silkscreen via its own rule */
  --font-serif: "Source Serif 4", Georgia, serif;
  background: var(--bg-frame);
  background-image:
    radial-gradient(1px 1px at 10% 20%, rgba(255, 255, 255, 0.55), transparent),
    radial-gradient(1px 1px at 30% 80%, rgba(255, 255, 255, 0.4), transparent),
    radial-gradient(1px 1px at 70% 40%, rgba(255, 255, 255, 0.5), transparent),
    radial-gradient(1px 1px at 90% 10%, rgba(255, 255, 255, 0.35), transparent),
    radial-gradient(1px 1px at 50% 60%, rgba(255, 255, 255, 0.45), transparent),
    linear-gradient(180deg, #12061f 0%, #1a0a2e 45%, #0f0518 100%);
  background-size:
    100% 100%,
    100% 100%,
    100% 100%,
    100% 100%,
    100% 100%,
    100% 100%;
}

html:has(body.theme-nyan) {
  background-color: #0a0414;
}

body.theme-nyan .site-footer,
body.theme-nyan main#main {
  position: relative;
  z-index: 2;
}

body.theme-nyan .site-footer {
  border-top: none;
}

body.theme-nyan .site-footer::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  height: 3px;
  background: linear-gradient(
    90deg,
    #ff0000,
    #ff9900,
    #ffff00,
    #33ff00,
    #0099ff,
    #6633ff,
    #ff00ff,
    #ff0000
  );
  background-size: 200% 100%;
  animation: nyan-rainbow-bar 4s linear infinite;
  opacity: 0.85;
}

body.theme-nyan main#main {
  background: var(--bg);
  box-shadow: 0 0 0 1px rgba(255, 255, 255, 0.06) inset;
}

body.theme-nyan .site-header {
  border-bottom-color: var(--border);
  background: linear-gradient(
    180deg,
    rgba(45, 27, 82, 0.98) 0%,
    rgba(26, 10, 46, 0.95) 100%
  );
}

body.theme-nyan .site-header::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 3px;
  background: linear-gradient(
    90deg,
    #ff0000,
    #ff9900,
    #ffff00,
    #33ff00,
    #0099ff,
    #6633ff,
    #ff00ff,
    #ff0000
  );
  background-size: 200% 100%;
  animation: nyan-rainbow-bar 4s linear infinite;
  opacity: 0.85;
}

@keyframes nyan-rainbow-bar {
  0% {
    background-position: 0% 0;
  }
  100% {
    background-position: 200% 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  body.theme-nyan .site-header::after,
  body.theme-nyan .site-footer::before {
    animation: none;
    background-position: 50% 0;
  }
}

body.theme-nyan .hero-kicker,
body.theme-nyan .hero h1,
body.theme-nyan .hero-name:not(.hero-name--zh),
body.theme-nyan .section-head h2 {
  font-family: "Silkscreen", "DM Sans", system-ui, sans-serif;
  font-weight: 400;
}

body.theme-nyan .hero-name--zh {
  font-family: Zpix, "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei",
    sans-serif;
  font-weight: normal;
  font-size: clamp(13px, 2.6vw, 15px);
  letter-spacing: 0.06em;
  line-height: 1.45;
  color: var(--ink);
  image-rendering: pixelated;
  -webkit-font-smoothing: none;
}

body.theme-nyan .hero-kicker {
  /* Silkscreen is wide; smaller fluid cap + tighter tracking keeps this on one line */
  font-size: clamp(0.785rem, 0.4rem + 1.85vw, 0.75rem);
  letter-spacing: 0.055em;
  text-transform: uppercase;
  background: linear-gradient(
    90deg,
    #ff6b9d,
    #ffc93c,
    #6bff9e,
    #6bcfff,
    #c96bff,
    #ff6b9d
  );
  background-size: 220% 100%;
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  animation: nyan-rainbow-text 6s linear infinite;
}

@media (max-width: 420px) {
  body.theme-nyan .hero-kicker {
    font-size: clamp(0.5rem, 3.15vw + 0.28rem, 0.6875rem);
    letter-spacing: 0.045em;
  }
}

@keyframes nyan-rainbow-text {
  0% {
    background-position: 0% 50%;
  }
  100% {
    background-position: 220% 50%;
  }
}

@media (prefers-reduced-motion: reduce) {
  body.theme-nyan .hero-kicker {
    animation: none;
    color: var(--accent);
    background: none;
    -webkit-background-clip: unset;
    background-clip: unset;
  }
}

body.theme-nyan .hero-aside {
  background: var(--surface);
  box-shadow: 0 0 0 1px rgba(255, 255, 255, 0.08) inset, var(--shadow-card);
}

body.theme-nyan .theme-night-toggle {
  border-color: var(--border);
  color: var(--ink);
  background: var(--surface);
}

body.theme-nyan .theme-night-toggle:hover {
  color: #ffff99;
  border-color: var(--accent-line);
}

body.theme-nyan .theme-night-toggle[aria-pressed="true"] {
  color: #fff;
  border-color: #ff6bcb;
  box-shadow: 0 0 12px rgba(255, 107, 203, 0.45);
}

body.theme-nyan .theme-night-toggle__icon {
  filter: drop-shadow(0 0 6px rgba(255, 180, 255, 0.35));
}

body.theme-nyan .nav-toggle-bar {
  background: var(--ink);
  box-shadow: 0 6px 0 var(--ink), 0 -6px 0 var(--ink);
}

/* Night theme only: small attribution (Nyan Cat is © Christopher Torres / PRguitarman) */
.theme-nyan-credit {
  display: none;
  margin: 0;
}

body.theme-nyan .theme-nyan-credit {
  display: block;
  position: fixed;
  right: max(0.65rem, env(safe-area-inset-right, 0px));
  bottom: max(0.45rem, env(safe-area-inset-bottom, 0px));
  z-index: 42;
  font-size: 0.68rem;
  font-weight: 500;
  letter-spacing: 0.03em;
  line-height: 1.35;
  text-align: right;
  color: rgba(247, 244, 255, 0.42);
  pointer-events: none;
}

body.theme-nyan .theme-nyan-credit a {
  color: rgba(255, 180, 220, 0.88);
  text-decoration: none;
  border-bottom: 1px solid rgba(255, 150, 220, 0.35);
  pointer-events: auto;
}

body.theme-nyan .theme-nyan-credit a:hover {
  color: #fff;
  border-bottom-color: rgba(255, 180, 220, 0.65);
}