/* ============================================================
   2026 NCTS Workshop — stylesheet
   Aesthetic: editorial / scholarly / warm-ivory paper with
   a single vermillion accent (a scholar's seal).
   ============================================================ */

:root {
  /* Palette */
  --paper:        #f4efe6;
  --paper-deep:   #ebe4d4;
  --ink:          #1a1814;
  --ink-soft:     #4a443c;
  --ink-faint:    #8a8275;
  --rule:         #c9bfa9;
  --rule-soft:    #d8cfb9;
  --accent:       #b8341e;   /* vermillion seal */
  --accent-deep:  #8a2615;
  --navy:         #1f2c44;

  /* Type */
  --display:  "Cormorant Garamond", "Songti TC", serif;
  --body:     "EB Garamond", "Songti TC", serif;
  --times:    "Times New Roman", Times, serif;
  --mono:     "JetBrains Mono", ui-monospace, monospace;

  /* Layout */
  --max:      1240px;
  --pad-x:    clamp(1.25rem, 4vw, 3.5rem);

  /* Motion */
  --ease:     cubic-bezier(.22, .61, .36, 1);
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  background: var(--paper);
  color: var(--ink);
  font-family: var(--body);
  font-size: 19px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
  position: relative;
}

/* paper grain */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 1;
  background-image:
    radial-gradient(rgba(26,24,20,0.03) 1px, transparent 1px),
    radial-gradient(rgba(26,24,20,0.025) 1px, transparent 1px);
  background-size: 3px 3px, 7px 7px;
  background-position: 0 0, 1.5px 1.5px;
  opacity: 0.7;
  mix-blend-mode: multiply;
}

img, svg { display: block; max-width: 100%; }

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

::selection { background: var(--accent); color: var(--paper); }


/* ============================================================
   TOP RIBBON
   ============================================================ */

.ribbon {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(244, 239, 230, 0.92);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--rule);
}

.ribbon__inner {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0.58rem var(--pad-x);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1.5rem;
  position: relative;
}

.ribbon__mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.72rem;
  flex: 0 0 auto;
  border-radius: 999px;
  outline-offset: 0.35rem;
  transition: opacity 0.3s var(--ease), transform 0.3s var(--ease);
}

.ribbon__mark:hover {
  opacity: 0.84;
  transform: translateY(-1px);
}

.ribbon__mark:focus-visible {
  outline: 2px solid var(--accent);
}

.ribbon__logo {
  width: clamp(62px, 5.8vw, 74px);
  height: clamp(44px, 4vw, 52px);
  object-fit: contain;
}

.ribbon__brand {
  font-family: var(--display);
  font-size: clamp(1.28rem, 2vw, 1.62rem);
  font-weight: 600;
  line-height: 1;
  color: var(--ink);
  letter-spacing: 0.04em;
  white-space: nowrap;
}

.ribbon__toggle {
  display: none;
  width: 2.75rem;
  height: 2.75rem;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  gap: 0.28rem;
  border: 1px solid var(--rule);
  border-radius: 999px;
  background: rgba(255, 252, 244, 0.54);
  color: var(--ink);
  cursor: pointer;
  transition: border-color 0.3s var(--ease), background 0.3s var(--ease), transform 0.3s var(--ease);
}

.ribbon__toggle:hover {
  border-color: rgba(132, 38, 42, 0.32);
  background: rgba(255, 252, 244, 0.78);
  transform: translateY(-1px);
}

.ribbon__toggle:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 0.25rem;
}

.ribbon__toggle span {
  width: 1.05rem;
  height: 1px;
  background: currentColor;
  transform-origin: center;
  transition: transform 0.3s var(--ease), opacity 0.2s var(--ease);
}

.ribbon__nav {
  display: flex;
  gap: 1.7rem;
  font-family: var(--mono);
  font-size: 0.74rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.ribbon__nav a {
  position: relative;
  color: var(--ink-soft);
  transition: color 0.3s var(--ease);
  padding: 0.25rem 0;
}

.ribbon__nav a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -2px;
  width: 0;
  height: 1px;
  background: var(--accent);
  transition: width 0.4s var(--ease);
}

.ribbon__nav a:hover { color: var(--ink); }
.ribbon__nav a:hover::after { width: 100%; }

@media (max-width: 820px) {
  .ribbon__toggle {
    display: inline-flex;
  }

  .ribbon.is-nav-open .ribbon__toggle span:nth-child(1) {
    transform: translateY(0.29rem) rotate(45deg);
  }

  .ribbon.is-nav-open .ribbon__toggle span:nth-child(2) {
    opacity: 0;
  }

  .ribbon.is-nav-open .ribbon__toggle span:nth-child(3) {
    transform: translateY(-0.29rem) rotate(-45deg);
  }

  .ribbon__nav {
    position: absolute;
    top: calc(100% + 0.55rem);
    left: var(--pad-x);
    right: var(--pad-x);
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0;
    padding: 0.65rem;
    background: rgba(244, 239, 230, 0.98);
    border: 1px solid var(--rule);
    box-shadow: 0 22px 60px -38px rgba(26, 24, 20, 0.42);
    opacity: 0;
    pointer-events: none;
    transform: translateY(-0.4rem);
    visibility: hidden;
    transition: opacity 0.25s var(--ease), transform 0.25s var(--ease), visibility 0.25s var(--ease);
  }

  .ribbon.is-nav-open .ribbon__nav {
    opacity: 1;
    pointer-events: auto;
    transform: translateY(0);
    visibility: visible;
  }

  .ribbon__nav a {
    display: block;
    padding: 0.78rem 0.85rem;
    border-bottom: 1px solid rgba(57, 50, 41, 0.1);
  }

  .ribbon__nav a:last-child {
    border-bottom: 0;
  }

  .ribbon__nav a::after {
    display: none;
  }
}

@media (max-width: 520px) {
  .ribbon__brand { display: none; }

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

  .ribbon__nav a:last-child {
    border-bottom: 0;
  }
}


/* ============================================================
   HERO
   ============================================================ */

.hero {
  position: relative;
  min-height: calc(100vh - 70px);
  padding: clamp(2.5rem, 6vw, 5rem) var(--pad-x) 4rem;
  overflow: hidden;
}

.hero__grid {
  max-width: var(--max);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 1fr;
  grid-template-rows: auto auto 1fr auto;
  gap: 1rem 3rem;
  position: relative;
  z-index: 2;
}

.hero__meta {
  grid-column: 1 / -1;
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--rule);
}

.kicker {
  font-family: var(--mono);
  font-size: 0.78rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--accent);
}

.kicker--muted {
  color: var(--ink-faint);
  letter-spacing: 0.3em;
}

.hero__title {
  grid-column: 1 / -1;
  font-family: var(--display);
  font-weight: 500;
  font-size: clamp(3rem, 9vw, 8.5rem);
  line-height: 0.95;
  letter-spacing: -0.02em;
  margin-top: clamp(1.5rem, 4vw, 3rem);
  color: var(--ink);
}

.title-line {
  display: block;
  opacity: 0;
  transform: translateY(20px);
  animation: rise 1.1s var(--ease) forwards;
}
.title-line:nth-child(1) { animation-delay: 0.05s; }
.title-line:nth-child(2) { animation-delay: 0.18s; }
.title-line:nth-child(3) { animation-delay: 0.30s; }
.title-line:nth-child(4) { animation-delay: 0.40s; }

.title-line--italic {
  font-style: italic;
  font-weight: 400;
  color: var(--accent);
  padding-left: 0.18em;
}

.title-line--small {
  font-size: 0.42em;
  font-weight: 500;
  font-style: italic;
  color: var(--ink-soft);
  padding-left: 0.4em;
  line-height: 1.1;
  letter-spacing: 0;
}

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

.hero__zh {
  grid-column: 1 / -1;
  font-family: var(--display);
  font-weight: 400;
  font-size: clamp(1.05rem, 1.6vw, 1.4rem);
  letter-spacing: 0.18em;
  color: var(--ink-soft);
  margin-top: 1.5rem;
  opacity: 0;
  animation: rise 1.1s var(--ease) 0.6s forwards;
}

.hero__details {
  grid-column: 1 / -1;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 2.5rem;
  margin-top: clamp(2.5rem, 5vw, 4rem);
  padding-top: 2rem;
  border-top: 1px solid var(--rule);
  opacity: 0;
  animation: rise 1.1s var(--ease) 0.75s forwards;
}

.detail {
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}

.detail__label {
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--ink-faint);
}

.detail__value {
  font-family: var(--display);
  font-size: clamp(1.1rem, 1.6vw, 1.35rem);
  font-weight: 500;
  color: var(--ink);
  line-height: 1.3;
}

.institution-logos {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
}

.institution-logos__link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  outline-offset: 0.35rem;
  transition: opacity 0.3s var(--ease), transform 0.3s var(--ease);
}

.institution-logos__link:hover {
  opacity: 0.82;
  transform: translateY(-1px);
}

.institution-logos__link:focus-visible {
  outline: 2px solid var(--accent);
}

.institution-logos img {
  display: block;
  width: auto;
  object-fit: contain;
}

.hero__seal {
  position: absolute;
  top: clamp(2rem, 4vw, 3.5rem);
  right: var(--pad-x);
  width: clamp(80px, 9vw, 130px);
  color: var(--accent);
  opacity: 0;
  animation: sealIn 1.4s var(--ease) 1s forwards;
}

@keyframes sealIn {
  from { opacity: 0; transform: rotate(-25deg) scale(0.85); }
  to   { opacity: 0.9; transform: rotate(-8deg) scale(1); }
}

.hero__rule { display: none; }

.hero__scroll {
  position: absolute;
  bottom: 2rem;
  left: var(--pad-x);
  display: none;
  flex-direction: column;
  align-items: center;
  gap: 0.6rem;
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--ink-faint);
  opacity: 0;
  animation: rise 1.1s var(--ease) 1.4s forwards;
}

.hero__scroll .arrow {
  font-size: 1rem;
  animation: bob 2.2s ease-in-out infinite;
}

@keyframes bob {
  0%, 100% { transform: translateY(0); }
  50%      { transform: translateY(6px); }
}

.hero__formula {
  position: absolute;
  bottom: -1rem;
  right: -1rem;
  font-family: var(--display);
  font-style: italic;
  font-size: clamp(4rem, 18vw, 13rem);
  color: var(--ink);
  opacity: 0.04;
  letter-spacing: -0.04em;
  pointer-events: none;
  white-space: nowrap;
  z-index: 1;
}

@media (max-width: 700px) {
  .hero__details {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }
  .hero__scroll {
    display: none;
  }
  .hero__seal {
    width: 70px;
    top: 1rem;
    right: 1rem;
  }
}


/* ============================================================
   SECTIONS (generic frame)
   ============================================================ */

.section {
  position: relative;
  z-index: 2;
  max-width: var(--max);
  margin: 0 auto;
  padding: clamp(4rem, 8vw, 7rem) var(--pad-x);
  border-top: 1px solid var(--rule);
}

.section__head {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 1.5rem;
  margin-bottom: clamp(2.5rem, 5vw, 4rem);
}

.section__number {
  font-family: var(--mono);
  font-size: 0.8rem;
  letter-spacing: 0.25em;
  color: var(--accent);
  padding-top: 0.45rem;
  align-self: start;
}

.section__title {
  font-family: var(--display);
  font-weight: 500;
  font-style: italic;
  font-size: clamp(2.2rem, 5vw, 3.8rem);
  letter-spacing: -0.01em;
  line-height: 1;
  color: var(--ink);
}

.section__rule {
  flex: 1;
  height: 1px;
  background: var(--rule);
  align-self: center;
  min-width: 60px;
}


/* ============================================================
   ABOUT
   ============================================================ */

.about__body {
  max-width: 780px;
  margin-left: auto;
}

.lede {
  font-family: var(--display);
  font-size: clamp(1.4rem, 2.6vw, 2rem);
  line-height: 1.35;
  font-style: italic;
  color: var(--ink);
  margin-bottom: 1.8rem;
  text-wrap: balance;
}

.about__body p {
  font-size: 1.1rem;
  line-height: 1.7;
  color: var(--ink-soft);
  margin-bottom: 1.4rem;
}

.about__body em {
  color: var(--accent);
  font-style: normal;
  font-weight: 500;
}

.about__topics {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin-top: 2.5rem;
  padding-top: 2rem;
  border-top: 1px dashed var(--rule);
}

.topic {
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  padding: 0.5rem 0.85rem;
  border: 1px solid var(--rule);
  color: var(--ink-soft);
  transition: all 0.3s var(--ease);
  cursor: default;
}

.topic:hover {
  background: var(--ink);
  color: var(--paper);
  border-color: var(--ink);
}


/* ============================================================
   SPEAKERS
   ============================================================ */

.speakers {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 0;
  border-top: 1px solid var(--rule);
}

.speaker {
  position: relative;
  padding: 1.8rem 1.5rem 1.8rem 0;
  border-bottom: 1px solid var(--rule);
  border-right: 1px solid var(--rule);
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0.9rem;
  align-items: baseline;
  transition: background 0.4s var(--ease);
}

.speaker:hover {
  background: var(--paper-deep);
}

.speaker:hover .speaker__name {
  color: var(--accent);
}

.speaker__index {
  font-family: var(--display);
  font-style: italic;
  font-size: 1rem;
  color: var(--ink-faint);
  padding-left: 1.2rem;
  min-width: 2.5rem;
}

.speaker__name {
  font-family: var(--times);
  font-weight: 500;
  font-size: 1.35rem;
  line-height: 1.2;
  color: var(--ink);
  letter-spacing: -0.005em;
  transition: color 0.3s var(--ease);
}

.speaker__link {
  display: inline-flex;
  align-items: baseline;
  gap: 0.35rem;
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s var(--ease), color 0.3s var(--ease);
}

.speaker__link::after {
  content: "↗";
  font-family: var(--mono);
  font-size: 0.62rem;
  line-height: 1;
  color: var(--ink-faint);
  transform: translateY(-0.16rem);
  transition: color 0.3s var(--ease), transform 0.3s var(--ease);
}

.speaker__link:hover,
.speaker__link:focus-visible {
  border-color: var(--accent);
  outline: none;
}

.speaker__link:hover::after,
.speaker__link:focus-visible::after {
  color: var(--accent);
  transform: translate(0.08rem, -0.22rem);
}

.speaker__affil {
  grid-column: 2;
  font-family: var(--body);
  font-style: italic;
  font-size: 0.9rem;
  color: var(--ink-soft);
  margin-top: 0.35rem;
  line-height: 1.4;
}


/* ============================================================
   ORGANIZERS
   ============================================================ */

.organizers {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 0.75rem;
}

.organizers__institutions {
  display: grid;
  grid-template-columns: minmax(8rem, 0.22fr) 1fr;
  align-items: center;
  gap: 1.2rem;
  margin-bottom: 1.2rem;
  padding: 1rem 1.1rem;
  border: 1px solid var(--rule);
  background: rgba(255, 252, 244, 0.52);
}

.organizers__label {
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--accent);
}

.institution-logos--organizers {
  gap: clamp(0.8rem, 2vw, 1.5rem);
}

.institution-logos--organizers img {
  max-width: min(26vw, 170px);
  max-height: 42px;
}

.institution-logos--organizers img[src$="NTNUMATH.png"] {
  max-width: 50px;
  max-height: 50px;
}

.organizer {
  padding: 1.05rem 1rem;
  border: 1px solid var(--rule);
  background: rgba(255, 252, 244, 0.34);
  position: relative;
  transition: background 0.3s var(--ease), border-color 0.3s var(--ease);
}

.organizer::before {
  content: none;
}

.organizer:hover {
  background: rgba(255, 252, 244, 0.68);
  border-color: rgba(132, 38, 42, 0.22);
}

.organizer__name {
  font-family: var(--display);
  font-weight: 500;
  font-size: 1.08rem;
  color: var(--ink);
  margin-bottom: 0.28rem;
  line-height: 1.2;
}

.organizer__link {
  display: inline-flex;
  align-items: baseline;
  gap: 0.35rem;
  border-bottom: 1px solid transparent;
  transition: color 0.3s var(--ease), border-color 0.3s var(--ease);
}

.organizer__link::after {
  content: "\2197";
  font-family: var(--mono);
  font-size: 0.56rem;
  color: var(--accent);
  transform: translateY(-0.18rem);
  opacity: 0.72;
}

.organizer:hover .organizer__link,
.organizer__link:hover,
.organizer__link:focus-visible {
  color: var(--accent);
  border-color: var(--accent);
  outline: none;
}

.organizer__link:hover::after,
.organizer__link:focus-visible::after {
  opacity: 1;
}

.organizer__affil {
  font-family: var(--body);
  font-style: italic;
  font-size: 0.8rem;
  color: var(--ink-soft);
}

@media (max-width: 700px) {
  .organizers__institutions {
    grid-template-columns: 1fr;
    gap: 0.8rem;
  }

  .institution-logos--organizers img {
    max-width: min(44vw, 150px);
    max-height: 38px;
  }

  .institution-logos--organizers img[src$="NTNUMATH.png"] {
    max-width: 46px;
    max-height: 46px;
  }
}


/* ============================================================
   PROGRAM
   ============================================================ */

.program__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: clamp(1.5rem, 3vw, 3rem);
  align-items: start;
}

@media (max-width: 820px) {
  .program__grid { grid-template-columns: 1fr; }
}

.program__day {
  background: var(--paper);
  border: 1px solid var(--rule);
  padding: 2rem clamp(1.2rem, 2.5vw, 2.2rem);
  position: relative;
}

.program__day::after {
  content: "";
  position: absolute;
  top: 0; left: 0;
  width: 100%; height: 3px;
  background: var(--ink);
}

.program__day-head {
  margin-bottom: 1.5rem;
  padding-bottom: 1.2rem;
  border-bottom: 1px solid var(--rule);
}

.program__day-tag {
  display: inline-block;
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.5rem;
}

.program__day-date {
  font-family: var(--times);
  font-weight: 500;
  font-style: italic;
  font-size: clamp(1.4rem, 2.2vw, 1.7rem);
  color: var(--ink);
  line-height: 1.2;
}

.program__day-place {
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin-top: 0.7rem;
}

.program__slots {
  list-style: none;
  display: flex;
  flex-direction: column;
}

.program__slots li {
  display: grid;
  grid-template-columns: 142px 1fr;
  gap: 1rem;
  padding: 0.85rem 0;
  border-bottom: 1px dashed var(--rule);
  align-items: baseline;
}

.program__slots li:last-child { border-bottom: none; }

.program__slots .time {
  font-family: var(--mono);
  font-size: 0.78rem;
  letter-spacing: 0.05em;
  color: var(--ink-faint);
}

.program__slots .event {
  font-family: var(--times);
  font-size: 1rem;
  color: var(--ink);
}

.program__talk {
  display: block;
}

.program__speaker {
  display: block;
  font-weight: 600;
  color: var(--ink);
}

.program__title {
  display: block;
  margin-top: 0.18rem;
  font-family: var(--times);
  font-size: 1.02rem;
  font-style: italic;
  line-height: 1.32;
  color: var(--ink-soft);
}

.program__abstract-link {
  display: inline-block;
  margin-top: 0.42rem;
  margin-left: 0;
  padding: 0.08rem 0.42rem 0.1rem;
  border: 1px solid var(--rule);
  color: var(--accent);
  font-family: var(--mono);
  font-size: 0.58rem;
  letter-spacing: 0.14em;
  line-height: 1.4;
  text-transform: uppercase;
  vertical-align: middle;
  white-space: nowrap;
  transition: all 0.3s var(--ease);
}

.program__abstract-link:hover {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--paper);
}

@media (max-width: 520px) {
  .program__slots li {
    grid-template-columns: 122px 1fr;
    gap: 0.75rem;
  }

  .program__slots .time {
    font-size: 0.68rem;
  }

  .program__abstract-link {
    margin-top: 0.35rem;
  }
}


/* ============================================================
   ABSTRACTS
   ============================================================ */

.abstracts__list {
  border-top: 1px solid var(--rule);
}

.abstract-card {
  display: grid;
  grid-template-columns: minmax(140px, 190px) minmax(0, 1fr);
  gap: clamp(1.5rem, 4vw, 4rem);
  padding: clamp(2rem, 4vw, 3rem) 0;
  border-bottom: 1px solid var(--rule);
  scroll-margin-top: 96px;
}

.abstract-card__meta {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.16em;
  line-height: 1.45;
  text-transform: uppercase;
  color: var(--ink-faint);
}

.abstract-card__meta span:first-child {
  color: var(--accent);
}

.abstract-card__body {
  max-width: 820px;
  font-family: var(--times);
}

.abstract-card__body h3 {
  font-family: var(--times);
  font-size: clamp(1.6rem, 3vw, 2.25rem);
  font-weight: 500;
  line-height: 1.12;
  color: var(--ink);
  letter-spacing: 0;
  overflow-wrap: anywhere;
}

.abstract-card__dash {
  font-family: var(--times);
}

.abstract-card__speaker {
  margin-top: 0.75rem;
  color: var(--accent);
  font-family: var(--times);
  font-size: 1rem;
  font-style: italic;
  line-height: 1.45;
}

.abstract-card__body p:not(.abstract-card__speaker) {
  margin-top: 1.15rem;
  color: var(--ink-soft);
  font-size: 1.03rem;
  line-height: 1.75;
}

.abstract-card__body strong {
  color: var(--ink);
  font-weight: 600;
}

@media (max-width: 760px) {
  .abstract-card {
    grid-template-columns: 1fr;
    gap: 1.2rem;
  }

  .abstract-card__meta {
    flex-direction: row;
    flex-wrap: wrap;
    gap: 0.45rem 1rem;
  }

  .abstract-card__body h3 {
    font-size: clamp(1.35rem, 7vw, 1.8rem);
  }
}


/* ============================================================
   VENUE
   ============================================================ */

.venue__body {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: clamp(2rem, 5vw, 5rem);
  align-items: start;
}

@media (max-width: 820px) {
  .venue__body { grid-template-columns: 1fr; }
}

.venue__name {
  font-family: var(--display);
  font-weight: 500;
  font-style: italic;
  font-size: clamp(2rem, 3.5vw, 2.8rem);
  color: var(--accent);
  margin-bottom: 1.2rem;
  letter-spacing: -0.01em;
  line-height: 1.1;
}

.venue__addr {
  font-size: 1.1rem;
  line-height: 1.6;
  color: var(--ink);
  margin-bottom: 1.4rem;
}

.venue__zh {
  font-family: var(--display);
  font-size: 1.05rem;
  line-height: 1.7;
  letter-spacing: 0.05em;
  color: var(--ink-soft);
  margin-bottom: 1.8rem;
  padding: 1.2rem 0;
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
}

.link-underline {
  font-family: var(--mono);
  font-size: 0.78rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--accent);
  border-bottom: 1px solid var(--accent);
  padding-bottom: 2px;
  transition: all 0.3s var(--ease);
}

.link-underline:hover {
  color: var(--accent-deep);
  border-color: var(--accent-deep);
  padding-bottom: 4px;
}

.venue__card {
  background: rgba(255, 252, 244, 0.42);
  color: var(--ink);
  padding: 2rem;
  position: relative;
  border: 1px solid var(--rule);
}

.venue__card::before {
  content: "";
  position: absolute;
  top: -1px; left: -1px; right: -1px;
  height: 3px;
  background: var(--accent);
}

.venue__card-label {
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.25em;
  text-transform: uppercase;
  color: var(--accent);
  display: block;
  margin-bottom: 1.2rem;
}

.venue__card p {
  font-size: 0.98rem;
  line-height: 1.65;
  margin-bottom: 1rem;
  color: var(--ink-soft);
  font-family: var(--body);
}

.venue__card p:last-child {
  margin-bottom: 0;
}

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


/* ============================================================
   ACCOMMODATION
   ============================================================ */

.accommodation__body {
  display: grid;
  grid-template-columns: minmax(220px, 0.75fr) minmax(0, 1.45fr);
  gap: clamp(2rem, 5vw, 4.5rem);
  align-items: start;
}

.accommodation__intro {
  position: sticky;
  top: 6.5rem;
}

.accommodation__lede {
  font-family: var(--display);
  font-size: clamp(1.45rem, 2.7vw, 2.05rem);
  font-style: italic;
  line-height: 1.35;
  color: var(--ink);
  text-wrap: balance;
}

.accommodation__note {
  margin-top: 1.4rem;
  padding-top: 1.4rem;
  border-top: 1px solid var(--rule);
  color: var(--ink-soft);
  font-size: 1rem;
  line-height: 1.65;
}

.accommodation__list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
}

.accommodation__item {
  min-height: 100%;
  padding: 1.45rem;
  border: 1px solid var(--rule);
  background: rgba(255, 252, 244, 0.34);
  display: flex;
  flex-direction: column;
  transition: background 0.35s var(--ease), border-color 0.35s var(--ease), transform 0.35s var(--ease);
}

.accommodation__item:hover {
  background: var(--paper-deep);
  border-color: var(--rule-soft);
  transform: translateY(-2px);
}

.accommodation__eyebrow {
  font-family: var(--mono);
  font-size: 0.68rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.9rem;
}

.accommodation__name {
  font-family: var(--display);
  font-weight: 500;
  font-size: clamp(1.35rem, 2vw, 1.7rem);
  line-height: 1.08;
  color: var(--ink);
  margin-bottom: 1rem;
}

.accommodation__link {
  display: inline-flex;
  flex-direction: column;
  gap: 0.28rem;
  border-bottom: 1px solid transparent;
  transition: color 0.3s var(--ease), border-color 0.3s var(--ease);
}

.accommodation__link::after {
  content: "中文網站 \2197";
  font-family: var(--mono);
  font-size: 0.62rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--accent);
  margin-top: 0.1rem;
}

.accommodation__link:hover,
.accommodation__link:focus-visible {
  color: var(--accent);
  border-color: var(--accent);
  outline: none;
}

.accommodation__address {
  color: var(--ink-soft);
  font-size: 0.98rem;
  line-height: 1.55;
}

.accommodation__access {
  margin-top: auto;
  padding-top: 1rem;
  border-top: 1px solid var(--rule-soft);
  color: var(--ink-faint);
  font-size: 0.92rem;
  line-height: 1.55;
}

@media (max-width: 980px) {
  .accommodation__body {
    grid-template-columns: 1fr;
  }

  .accommodation__intro {
    position: static;
  }
}

@media (max-width: 700px) {
  .accommodation__list {
    grid-template-columns: 1fr;
  }
}


/* ============================================================
   REGISTRATION
   ============================================================ */

.register__body {
  max-width: 820px;
  margin: 0 auto;
  text-align: center;
}

.register__lede {
  font-family: var(--display);
  font-size: clamp(1.4rem, 2.5vw, 1.9rem);
  line-height: 1.45;
  font-style: italic;
  color: var(--ink);
  margin-bottom: 3rem;
  text-wrap: balance;
}

.register__fees {
  max-width: 760px;
  margin: -1rem auto 2.8rem;
  padding: 1.35rem 0 1.45rem;
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
  text-align: left;
}

.register__fees-title {
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.75rem;
}

.register__fees-note {
  font-size: 1.05rem;
  line-height: 1.65;
  color: var(--ink-soft);
  margin-bottom: 1.2rem;
}

.register__fee-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.3rem 2rem;
}

.register__fee-item {
  padding-left: 1rem;
  border-left: 2px solid var(--accent);
}

.register__fee-role {
  display: block;
  font-family: var(--display);
  font-size: 1.2rem;
  line-height: 1.2;
  color: var(--ink);
  margin-bottom: 0.45rem;
}

.register__fee-item p {
  font-size: 1rem;
  line-height: 1.65;
  color: var(--ink-soft);
}

.register__cta {
  display: inline-flex;
  align-items: center;
  gap: 1.2rem;
  padding: 1.3rem 2.5rem;
  background: var(--accent);
  color: var(--paper);
  font-family: var(--display);
  font-size: 1.3rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  position: relative;
  overflow: hidden;
  transition: all 0.5s var(--ease);
}

.register__cta::before {
  content: "";
  position: absolute;
  inset: 0;
  background: var(--ink);
  transform: translateX(-101%);
  transition: transform 0.5s var(--ease);
  z-index: 0;
}

.register__cta:hover::before { transform: translateX(0); }

.register__cta .cta-text,
.register__cta .cta-arrow {
  position: relative;
  z-index: 1;
}

.register__cta .cta-arrow {
  font-size: 1.5rem;
  transition: transform 0.4s var(--ease);
}

.register__cta:hover .cta-arrow {
  transform: translateX(8px);
}

@media (max-width: 620px) {
  .register__fees {
    margin-top: -0.8rem;
    padding-left: 0;
    padding-right: 0;
  }

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


/* ============================================================
   HISTORY
   ============================================================ */

.history__body {
  max-width: 860px;
  margin-left: auto;
}

.history__intro {
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 1.2rem;
}

.history__list {
  list-style: none;
  border-top: 1px solid var(--rule);
}

.history__item {
  display: grid;
  grid-template-columns: 96px 116px minmax(0, 1fr);
  gap: 1rem;
  align-items: baseline;
  padding: 1rem 1.1rem;
  border-bottom: 1px solid var(--rule);
}

.history__item--current {
  background: var(--paper-deep);
  border-left: 3px solid var(--accent);
  padding-left: calc(1.1rem - 3px);
}

.history__edition,
.history__year {
  font-family: var(--mono);
  font-size: 0.78rem;
  letter-spacing: 0.1em;
  color: var(--ink-faint);
}

.history__item--current .history__edition,
.history__item--current .history__year {
  color: var(--accent);
}

.history__venue {
  font-family: var(--display);
  font-size: clamp(1.2rem, 2vw, 1.45rem);
  line-height: 1.25;
  color: var(--ink);
  letter-spacing: 0.02em;
}

.history__venue--link {
  justify-self: start;
  border-bottom: 1px solid var(--rule);
  transition: color 0.3s var(--ease), border-color 0.3s var(--ease);
}

.history__venue--link:hover {
  color: var(--accent);
  border-color: var(--accent);
}

@media (max-width: 620px) {
  .history__item {
    grid-template-columns: 1fr auto;
    gap: 0.3rem 0.9rem;
    padding: 1rem 0;
  }

  .history__item--current {
    padding-left: 0.8rem;
    padding-right: 0.8rem;
  }

  .history__venue {
    grid-column: 1 / -1;
  }
}


/* ============================================================
   FOOTER
   ============================================================ */

.footer {
  background: var(--paper-deep);
  color: var(--ink);
  position: relative;
  z-index: 2;
  margin-top: 4rem;
  border-top: 1px solid var(--rule);
}

.footer::before {
  content: "";
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: var(--accent);
}

.footer__inner {
  max-width: var(--max);
  margin: 0 auto;
  padding: 4rem var(--pad-x) 2rem;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 2.5rem;
}

@media (max-width: 820px) {
  .footer__inner { grid-template-columns: 1fr; gap: 2rem; }
}

.footer__col--right { text-align: right; }
@media (max-width: 820px) { .footer__col--right { text-align: left; } }

.footer__label {
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.25em;
  text-transform: uppercase;
  color: var(--accent);
  display: block;
  margin-bottom: 0.9rem;
}

.footer__col p {
  font-family: var(--display);
  font-size: 1.05rem;
  line-height: 1.55;
  margin-bottom: 0.8rem;
  color: var(--ink);
}

.institution-logos--footer {
  gap: 0.65rem;
  align-items: center;
}

.institution-logos--footer img {
  max-width: 118px;
  max-height: 38px;
}

.institution-logos--footer img[src$="NTNUMATH.png"] {
  max-width: 42px;
  max-height: 42px;
}

.footer .link-underline {
  color: var(--accent);
  border-color: var(--accent);
}
.footer .link-underline:hover {
  color: var(--accent-deep);
  border-color: var(--accent-deep);
}

.footer__bottom {
  grid-column: 1 / -1;
  margin-top: 2.5rem;
  padding-top: 2rem;
  border-top: 1px solid var(--rule);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.18em;
  color: var(--ink-faint);
}

.footer__motif {
  font-family: var(--display);
  font-style: italic;
  font-size: 1rem;
  letter-spacing: 0.1em;
  color: var(--accent);
  opacity: 0.7;
}

@media (max-width: 700px) {
  .footer__bottom { flex-direction: column; gap: 1.2rem; text-align: center; }
}


/* ============================================================
   REVEAL ON SCROLL
   ============================================================ */

.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.9s var(--ease), transform 0.9s var(--ease);
}
.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}


/* ============================================================
   REDUCED MOTION
   ============================================================ */

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
  .reveal { opacity: 1; transform: none; }
}