:root {
  color-scheme: light;
  --navy-950: #071e35;
  --navy-900: #0b3155;
  --navy-800: #12466f;
  --teal-700: #08736e;
  --teal-600: #0b8b84;
  --teal-100: #dff4f1;
  --aqua-50: #f3fbfa;
  --ink: #13283b;
  --muted: #5b6d7c;
  --line: #d9e3ea;
  --paper: #ffffff;
  --canvas: #f4f7f9;
  --warm: #f5a623;
  --danger: #aa3a2e;
  --shadow: 0 24px 60px rgba(7, 30, 53, 0.09);
  --radius-lg: 1.5rem;
  --radius-md: 1rem;
  --content: 74rem;
}

* {
  box-sizing: border-box;
}

[hidden] {
  display: none !important;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 6rem;
}

body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at 90% 7%, rgba(11, 139, 132, 0.12), transparent 20rem),
    linear-gradient(180deg, #fbfdfe 0, var(--canvas) 36rem, var(--canvas) 100%);
  font-family: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans TC", sans-serif;
  font-size: 1rem;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
}

button,
a {
  -webkit-tap-highlight-color: transparent;
}

:focus-visible {
  outline: 3px solid var(--warm);
  outline-offset: 3px;
}

.lang-en {
  display: none !important;
}

html[data-language="en"] .lang-zh {
  display: none !important;
}

html[data-language="en"] .lang-en {
  display: revert !important;
}

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

.skip-link {
  position: fixed;
  z-index: 100;
  top: 0.75rem;
  left: 0.75rem;
  padding: 0.75rem 1rem;
  color: white;
  background: var(--navy-950);
  border-radius: 0.5rem;
  transform: translateY(-160%);
  transition: transform 160ms ease;
}

.skip-link:focus {
  transform: translateY(0);
}

.site-header {
  position: sticky;
  z-index: 20;
  top: 0;
  color: white;
  background: rgba(7, 30, 53, 0.96);
  border-bottom: 1px solid rgba(255, 255, 255, 0.13);
  backdrop-filter: blur(18px);
}

.header-inner,
main,
footer {
  width: min(calc(100% - 2.5rem), var(--content));
  margin-inline: auto;
}

.header-inner {
  min-height: 4.75rem;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 1.5rem;
}

.brand {
  min-height: 2.75rem;
  display: inline-flex;
  align-items: center;
  justify-self: start;
  gap: 0.75rem;
  text-decoration: none;
}

.brand-mark {
  width: 2.5rem;
  aspect-ratio: 1;
  display: grid;
  place-items: center;
  border: 1px solid rgba(255, 255, 255, 0.5);
  border-radius: 50%;
  color: #91ddd7;
  font-size: 0.65rem;
  font-weight: 800;
  letter-spacing: 0.08em;
}

.brand strong,
.brand small {
  display: block;
}

.brand strong {
  line-height: 1;
  letter-spacing: 0.14em;
}

.brand small {
  margin-top: 0.22rem;
  color: #c7d6e1;
  font-size: 0.72rem;
  line-height: 1.2;
}

.primary-nav {
  display: flex;
  justify-content: center;
  gap: 1.5rem;
}

.primary-nav a {
  min-height: 2.75rem;
  display: inline-flex;
  align-items: center;
  padding: 0.4rem 0;
  color: #dce7ee;
  border-bottom: 2px solid transparent;
  text-decoration: none;
  font-size: 0.92rem;
  font-weight: 650;
}

.primary-nav a:hover {
  color: white;
  border-bottom-color: var(--teal-600);
}

.language-switch {
  justify-self: end;
  display: inline-flex;
  padding: 0.2rem;
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.16);
  border-radius: 999px;
}

.language-switch button {
  min-width: 2.75rem;
  min-height: 2.75rem;
  padding: 0.35rem 0.65rem;
  color: #dce7ee;
  background: transparent;
  border: 0;
  border-radius: 999px;
  cursor: pointer;
  font: inherit;
  font-size: 0.8rem;
  font-weight: 800;
}

.language-switch button[aria-pressed="true"] {
  color: var(--navy-950);
  background: white;
}

main {
  padding-bottom: 5rem;
}

.intro {
  min-height: 31rem;
  display: grid;
  grid-template-columns: minmax(0, 1.7fr) minmax(13rem, 0.55fr);
  align-items: center;
  gap: clamp(2.5rem, 8vw, 8rem);
  padding: 5rem 0 3.5rem;
}

.eyebrow,
.section-number,
.event-kicker,
.field-label {
  margin: 0;
  color: var(--teal-700);
  font-size: 0.78rem;
  font-weight: 850;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.intro h1 {
  max-width: 12ch;
  margin: 0.55rem 0 0;
  color: var(--navy-950);
  font-family: "Noto Serif TC", "Songti TC", Georgia, serif;
  font-size: clamp(3rem, 8vw, 6.8rem);
  font-weight: 800;
  letter-spacing: -0.065em;
  line-height: 0.98;
}

.english-title {
  margin: 1rem 0 0;
  color: var(--navy-800);
  font-family: Georgia, "Times New Roman", serif;
  font-size: clamp(1.35rem, 3vw, 2rem);
  font-style: italic;
  line-height: 1.2;
}

.intro-text {
  max-width: 38rem;
  margin: 1.75rem 0 0;
  color: var(--muted);
  font-size: 1.08rem;
}

.semester-stamp {
  position: relative;
  aspect-ratio: 1;
  display: grid;
  place-content: center;
  justify-items: center;
  color: white;
  background: var(--navy-900);
  border-radius: 50%;
  box-shadow: 0 28px 70px rgba(7, 30, 53, 0.22);
}

.semester-stamp::before,
.semester-stamp::after {
  position: absolute;
  content: "";
  border-radius: 50%;
}

.semester-stamp::before {
  inset: 0.7rem;
  border: 1px solid rgba(255, 255, 255, 0.32);
}

.semester-stamp::after {
  width: 1.1rem;
  height: 1.1rem;
  right: 10%;
  bottom: 12%;
  background: var(--teal-600);
  box-shadow: -10rem -8rem 0 0 var(--warm);
}

.semester-stamp span,
.semester-stamp strong,
.semester-stamp small {
  position: relative;
  z-index: 1;
}

.semester-stamp span {
  font-family: Georgia, serif;
  font-size: clamp(3rem, 7vw, 5.5rem);
  line-height: 0.9;
}

.semester-stamp strong {
  margin-top: 0.65rem;
  font-size: 1.05rem;
  letter-spacing: 0.18em;
}

.semester-stamp small {
  margin-top: 0.45rem;
  color: #91ddd7;
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.12em;
}

.essentials {
  display: grid;
  grid-template-columns: 0.75fr 1.2fr 1.25fr;
  overflow: hidden;
  color: white;
  background: var(--navy-950);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
}

.essential-card {
  min-height: 11.5rem;
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 1rem;
  padding: 1.7rem;
  border-right: 1px solid rgba(255, 255, 255, 0.13);
  transition: background-color 180ms ease, box-shadow 180ms ease;
}

.essential-card:last-child {
  border-right: 0;
}

.essential-card--accent {
  color: var(--navy-950);
  background: var(--teal-100);
}

.essential-index {
  color: #77cec8;
  font-family: Georgia, serif;
  font-size: 0.88rem;
}

.essential-card--accent .essential-index {
  color: var(--teal-700);
}

.essential-card h3 {
  margin: 0 0 0.45rem;
  font-size: 1rem;
}

.essential-card p {
  margin: 0;
  color: #d4e0e8;
  font-size: 1.02rem;
  line-height: 1.55;
}

.essential-card--accent p {
  color: #244754;
}

.section-nav {
  display: flex;
  gap: 0.75rem;
  padding: 1.5rem 0 0;
}

.button {
  min-height: 3rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 1.6rem;
  padding: 0.75rem 1.1rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 750;
  transition: transform 160ms ease, box-shadow 160ms ease, background 160ms ease;
}

.button:hover {
  transform: translateY(-2px);
}

.button--primary {
  color: white;
  background: var(--teal-700);
  border-color: var(--teal-700);
  box-shadow: 0 8px 22px rgba(8, 115, 110, 0.19);
}

.button--secondary {
  color: var(--navy-900);
  background: white;
}

.content-section {
  padding-top: 7rem;
}

.section-heading {
  display: grid;
  grid-template-columns: minmax(18rem, 1fr) minmax(18rem, 0.7fr);
  align-items: end;
  gap: 3rem;
  margin-bottom: 2rem;
}

.section-heading h2 {
  margin: 0.15rem 0 0;
  color: var(--navy-950);
  font-family: "Noto Serif TC", "Songti TC", Georgia, serif;
  font-size: clamp(2rem, 5vw, 3.7rem);
  letter-spacing: -0.045em;
  line-height: 1.1;
}

.section-description {
  max-width: 34rem;
  margin: 0;
  color: var(--muted);
}

.timeline {
  display: grid;
  gap: 0.8rem;
}

.official-sync {
  width: fit-content;
  max-width: 100%;
  display: flex;
  align-items: center;
  gap: 0.65rem;
  margin: -0.45rem 0 1.35rem;
  padding: 0.65rem 0.85rem;
  color: var(--muted);
  background: rgba(255, 255, 255, 0.72);
  border: 1px solid var(--line);
  border-radius: 999px;
  font-size: 0.8rem;
  line-height: 1.35;
}

.official-sync__indicator {
  width: 0.55rem;
  height: 0.55rem;
  flex: 0 0 auto;
  background: var(--teal-600);
  border-radius: 50%;
}

.official-sync[data-sync-state="loading"] .official-sync__indicator {
  animation: sync-pulse 1.2s ease-in-out infinite;
}

.official-sync[data-sync-state="updated"] {
  color: var(--teal-700);
  background: var(--aqua-50);
  border-color: rgba(8, 115, 110, 0.28);
}

.official-sync[data-sync-state="review"] .official-sync__indicator {
  background: var(--warm);
}

.official-sync[data-sync-state="unavailable"] .official-sync__indicator {
  background: var(--danger);
}

.official-sync a,
.official-source {
  color: var(--teal-700);
  font-weight: 750;
  text-underline-offset: 0.18em;
}

.official-sync a {
  margin-left: 0.15rem;
  white-space: nowrap;
}

@keyframes sync-pulse {
  50% {
    opacity: 0.35;
    transform: scale(0.72);
  }
}

.event-card {
  position: relative;
  display: grid;
  grid-template-columns: 8.7rem minmax(0, 1fr) minmax(9rem, 0.34fr);
  gap: clamp(1.5rem, 4vw, 3.5rem);
  padding: 1.8rem;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  box-shadow: 0 10px 30px rgba(11, 49, 85, 0.045);
  transition: transform 180ms ease, border-color 180ms ease, box-shadow 180ms ease, opacity 180ms ease;
}

.event-card::before {
  position: absolute;
  inset: 0 auto 0 0;
  width: 0.28rem;
  content: "";
  background: transparent;
  border-radius: var(--radius-md) 0 0 var(--radius-md);
}

.event-card.is-next {
  border-color: rgba(8, 115, 110, 0.42);
  box-shadow: 0 16px 42px rgba(8, 115, 110, 0.12);
}

.event-card.is-next::before {
  background: var(--teal-600);
}

.event-card.is-past {
  opacity: 0.68;
}

.event-card.is-officially-updated {
  border-color: rgba(8, 115, 110, 0.3);
}

.event-card--special {
  background: linear-gradient(100deg, #fffdf6, #ffffff 45%);
}

.event-date time,
.event-date span,
.event-host span,
.event-host strong {
  display: block;
}

.event-date strong {
  color: var(--navy-950);
  font-family: Georgia, serif;
  font-size: 2rem;
  line-height: 1;
}

.event-date time > span {
  margin-top: 0.4rem;
  color: var(--muted);
  font-size: 0.72rem;
  font-weight: 750;
  letter-spacing: 0.11em;
}

.event-status {
  width: fit-content;
  margin-top: 1rem;
  padding: 0.28rem 0.55rem;
  color: var(--teal-700);
  background: var(--teal-100);
  border-radius: 999px;
  font-size: 0.72rem;
  font-weight: 800;
}

.event-main h3 {
  margin: 0.25rem 0 0.2rem;
  color: var(--navy-950);
  font-family: "Noto Serif TC", "Songti TC", Georgia, serif;
  font-size: clamp(1.35rem, 2.6vw, 1.8rem);
  line-height: 1.25;
}

.event-main h3 span {
  margin-left: 0.45rem;
  color: var(--navy-800);
  font-family: Georgia, serif;
  font-size: 0.82em;
  font-weight: 500;
}

.affiliation {
  margin: 0;
  color: var(--muted);
  font-size: 0.92rem;
}

.talk-title {
  max-width: 52rem;
  margin: 1rem 0 0;
  color: var(--ink);
  font-family: Georgia, "Times New Roman", serif;
  font-size: 1.08rem;
  font-weight: 650;
  line-height: 1.45;
}

.talk-title--pending {
  color: #687885;
  font-family: inherit;
  font-size: 0.94rem;
  font-style: italic;
  font-weight: 550;
}

.official-source {
  width: fit-content;
  min-height: 2.75rem;
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  margin-top: 0.65rem;
  font-size: 0.8rem;
}

.event-host {
  align-self: center;
  padding-left: 1.5rem;
  border-left: 1px solid var(--line);
}

.event-host strong {
  margin-top: 0.4rem;
  color: var(--navy-950);
  font-size: 1rem;
}

.event-host > span:last-child {
  color: var(--muted);
  font-family: Georgia, serif;
  font-size: 0.88rem;
}

.regulations {
  overflow: hidden;
  background: white;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
}

.regulations details + details {
  border-top: 1px solid var(--line);
}

.regulations summary {
  min-height: 4.8rem;
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1rem 1.5rem;
  color: var(--navy-950);
  cursor: pointer;
  font-family: "Noto Serif TC", "Songti TC", Georgia, serif;
  font-size: 1.2rem;
  font-weight: 750;
}

.regulations summary::marker {
  color: var(--teal-700);
}

.regulations summary span {
  color: var(--teal-700);
  font-family: Georgia, serif;
  font-size: 0.75rem;
  letter-spacing: 0.08em;
}

.regulations details[open] summary {
  background: var(--aqua-50);
}

.details-content {
  padding: 0.2rem 2rem 1.7rem 4.5rem;
  color: #334b5e;
}

.details-content ul {
  margin: 0;
  padding-left: 1.2rem;
}

.details-content li + li {
  margin-top: 0.75rem;
}

.details-content p {
  margin: 0;
}

.details-content code {
  padding: 0.18rem 0.35rem;
  color: var(--navy-900);
  background: #edf2f5;
  border-radius: 0.3rem;
  font-size: 0.9em;
  overflow-wrap: anywhere;
}

.contact-list {
  display: grid;
  gap: 0.75rem;
}

.contact-list a {
  min-height: 2.75rem;
  width: fit-content;
  display: grid;
  grid-template-columns: 9rem minmax(0, 1fr);
  gap: 1rem;
  color: var(--navy-800);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.2em;
  align-items: center;
}

.contact-list a span {
  overflow-wrap: anywhere;
}

.source-warning {
  max-width: 48rem;
  margin-top: 0.55rem !important;
  color: var(--danger);
  font-size: 0.9rem;
}

.source-panel {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 2rem;
  margin-top: 1rem;
  padding: 1.5rem;
  color: white;
  background: var(--navy-900);
  border-radius: var(--radius-md);
}

.source-panel strong {
  font-size: 1.08rem;
}

.source-panel p {
  max-width: 44rem;
  margin: 0.3rem 0 0;
  color: #cfdee7;
  font-size: 0.92rem;
}

.source-links {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: flex-end;
  gap: 0.45rem;
}

.source-links a {
  min-height: 2.75rem;
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  color: #a7e6e1;
  font-size: 0.9rem;
  font-weight: 720;
  text-underline-offset: 0.22em;
}

footer {
  display: flex;
  justify-content: space-between;
  gap: 2rem;
  padding: 2.3rem 0 3rem;
  color: #627584;
  border-top: 1px solid var(--line);
  font-size: 0.82rem;
}

footer strong {
  color: var(--navy-900);
  letter-spacing: 0.04em;
}

footer p {
  margin: 0.25rem 0 0;
}

footer > a {
  min-height: 2.75rem;
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  align-self: flex-start;
  color: var(--navy-800);
  font-weight: 750;
  text-underline-offset: 0.2em;
}

@media (hover: hover) and (pointer: fine) {
  .essential-card:not(.essential-card--accent):hover {
    background: #0d3a63;
  }

  .essential-card--accent:hover {
    background: #cfede9;
  }

  .event-card:hover,
  .event-card:focus-within {
    z-index: 1;
    border-color: rgba(8, 115, 110, 0.38);
    box-shadow: 0 18px 46px rgba(7, 30, 53, 0.12);
    transform: translateY(-4px);
  }

  .event-card:hover::before,
  .event-card:focus-within::before {
    background: var(--teal-600);
  }

  .event-card.is-past:hover,
  .event-card.is-past:focus-within {
    opacity: 0.88;
  }

  .regulations summary:hover {
    background: var(--aqua-50);
  }

  .official-sync a:hover,
  .official-source:hover,
  .source-links a:hover,
  footer > a:hover {
    color: var(--navy-950);
  }
}

@media (max-width: 860px) {
  .header-inner {
    grid-template-columns: 1fr auto;
  }

  .primary-nav {
    display: none;
  }

  .intro {
    grid-template-columns: minmax(0, 1fr) 11rem;
    gap: 2rem;
  }

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

  .essential-card:nth-of-type(2) {
    border-right: 0;
  }

  .essential-card--accent {
    grid-column: 1 / -1;
    min-height: auto;
  }

  .section-heading {
    grid-template-columns: 1fr;
    gap: 0.8rem;
  }

  .event-card {
    grid-template-columns: 7rem minmax(0, 1fr);
  }

  .event-host {
    grid-column: 2;
    padding: 0;
    border: 0;
  }

  .source-panel {
    grid-template-columns: 1fr;
  }

  .source-links {
    align-items: flex-start;
  }
}

@media (max-width: 600px) {
  .header-inner,
  main,
  footer {
    width: min(calc(100% - 1.5rem), var(--content));
  }

  .site-header {
    position: relative;
  }

  .header-inner {
    min-height: 4.35rem;
  }

  .brand small {
    max-width: 12rem;
  }

  .intro {
    min-height: auto;
    grid-template-columns: 1fr;
    padding: 3.8rem 0 2.5rem;
  }

  .intro h1 {
    font-size: clamp(3rem, 16vw, 4.8rem);
  }

  .semester-stamp {
    width: 9.3rem;
    justify-self: end;
    margin-top: -1rem;
  }

  .semester-stamp::after {
    box-shadow: -7rem -5.3rem 0 0 var(--warm);
  }

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

  .essential-card,
  .essential-card--accent {
    grid-column: auto;
    min-height: auto;
    padding: 1.3rem;
    border-right: 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.13);
  }

  .essential-card:last-child {
    border-bottom: 0;
  }

  .section-nav {
    flex-direction: column;
  }

  .button {
    justify-content: space-between;
  }

  .content-section {
    padding-top: 5rem;
  }

  .official-sync {
    width: 100%;
    flex-wrap: wrap;
    border-radius: var(--radius-md);
  }

  .event-card {
    grid-template-columns: 1fr;
    gap: 1.1rem;
    padding: 1.35rem;
  }

  .event-date {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
  }

  .event-date strong {
    font-size: 1.65rem;
  }

  .event-date time > span {
    display: inline-block;
    margin: 0 0 0 0.55rem;
  }

  .event-status {
    margin: 0;
  }

  .event-main h3 span {
    display: block;
    margin: 0.15rem 0 0;
  }

  .event-host {
    grid-column: auto;
    display: grid;
    grid-template-columns: 5rem 1fr;
    column-gap: 0.65rem;
    align-items: baseline;
    padding-top: 1rem;
    border-top: 1px solid var(--line);
  }

  .event-host .field-label {
    grid-row: 1 / 3;
  }

  .event-host strong {
    margin: 0;
  }

  .regulations summary {
    min-height: 4.4rem;
    padding: 0.9rem 1rem;
  }

  .details-content {
    padding: 0.15rem 1.15rem 1.4rem 1.55rem;
  }

  .contact-list a {
    grid-template-columns: 1fr;
    gap: 0;
  }

  footer {
    flex-direction: column;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
}

@media print {
  body {
    background: white;
  }

  .site-header,
  .section-nav,
  .source-panel,
  footer {
    display: none;
  }

  main {
    width: 100%;
    padding: 0;
  }

  .intro {
    min-height: auto;
    padding: 1rem 0 2rem;
  }

  .semester-stamp {
    color: var(--ink);
    background: white;
    border: 2px solid var(--navy-900);
    box-shadow: none;
  }

  .essentials,
  .essential-card,
  .essential-card--accent {
    color: var(--ink);
    background: white;
    border-color: var(--line);
    box-shadow: none;
  }

  .essential-card p {
    color: var(--ink);
  }

  .content-section {
    padding-top: 2rem;
  }

  .event-card,
  .regulations {
    break-inside: avoid;
    box-shadow: none;
  }

  .event-card.is-past {
    opacity: 1;
  }
}