:root {
  --navy: #062f46;
  --deep: #071e2b;
  --ocean: #0d7992;
  --teal: #55c7c0;
  --sand: #d4a726;
  --coral: #b85d3d;
  --mist: #edf7f8;
  --paper: #fbfbf8;
  --line: #d7e6ea;
  --ink: #082335;
  --muted: #5f7180;
  --white: #ffffff;
  --shadow: 0 18px 50px rgba(8, 35, 53, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: Inter, "Segoe UI", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.6;
}

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

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(255, 255, 255, 0.95);
  border-bottom: 1px solid rgba(6, 47, 70, 0.08);
  backdrop-filter: blur(18px);
}

.utility-bar {
  background: var(--deep);
  color: rgba(255, 255, 255, 0.72);
  font-size: 0.875rem;
}

.utility-inner,
.main-nav,
.section-inner {
  width: min(1200px, calc(100% - 48px));
  margin: 0 auto;
}

.utility-inner {
  min-height: 34px;
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 20px;
}

.language-toggle {
  display: inline-flex;
  align-items: center;
  border: 1px solid rgba(255, 255, 255, 0.25);
  border-radius: 999px;
  overflow: hidden;
}

.language-toggle a,
.language-toggle span,
.language-toggle button {
  min-width: 42px;
  padding: 4px 11px;
  text-align: center;
}

.language-toggle .active {
  background: var(--sand);
  color: var(--deep);
  font-weight: 800;
}

.language-toggle button {
  border: 0;
  background: transparent;
  color: inherit;
  font: inherit;
  cursor: pointer;
}

.main-nav {
  min-height: 86px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
}

.brand {
  display: inline-flex;
  align-items: center;
  min-width: 230px;
}

.wave-brand img {
  width: 230px;
  height: 62px;
  object-fit: contain;
  object-position: left center;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 22px;
  color: #243443;
  font-weight: 700;
}

.nav-links a {
  padding: 8px 0;
}

.nav-links a:hover,
.nav-links a:focus-visible {
  color: var(--ocean);
}

.nav-cta {
  background: var(--navy);
  color: var(--white) !important;
  padding: 13px 24px !important;
  border-radius: 999px;
  box-shadow: 0 10px 24px rgba(6, 47, 70, 0.2);
}

.nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--white);
  padding: 10px;
}

.nav-toggle span {
  display: block;
  height: 2px;
  margin: 5px 0;
  background: var(--navy);
}

.hero {
  position: relative;
  min-height: 690px;
  display: flex;
  align-items: center;
  overflow: hidden;
  color: var(--white);
}

.hero-media,
.hero-overlay {
  position: absolute;
  inset: 0;
}

.hero-media {
  background-image: url("./assets/nanjing-panorama.jpg");
  background-size: cover;
  background-position: center;
  transform: scale(1.02);
}

.hero-overlay {
  background:
    linear-gradient(90deg, rgba(4, 26, 39, 0.92) 0%, rgba(4, 33, 50, 0.78) 42%, rgba(9, 76, 98, 0.36) 100%),
    linear-gradient(0deg, rgba(4, 26, 39, 0.52), rgba(4, 26, 39, 0.08));
}

.hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 62px;
  background: linear-gradient(175deg, transparent 0 45%, var(--paper) 47% 100%);
}

.hero-content {
  position: relative;
  z-index: 2;
  width: min(1200px, calc(100% - 48px));
  margin: 0 auto;
  padding: 74px 0 96px;
}

.eyebrow,
.section-kicker {
  margin: 0 0 14px;
  color: var(--sand);
  font-weight: 900;
  text-transform: uppercase;
}

.eyebrow {
  display: inline-block;
  padding: 9px 18px;
  border: 1px solid rgba(255, 255, 255, 0.3);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.12);
  color: rgba(255, 255, 255, 0.92);
  font-size: 0.86rem;
}

.hero h1 {
  margin: 0;
  font-size: 4.6rem;
  line-height: 1;
  font-weight: 900;
}

.theme {
  max-width: 720px;
  margin: 18px 0 0;
  color: #f4d562;
  font-size: 2rem;
  line-height: 1.22;
  font-weight: 850;
}

.hero-copy {
  max-width: 660px;
  margin: 22px 0 0;
  color: rgba(255, 255, 255, 0.88);
  font-size: 1.18rem;
}

.hero-actions,
.footer-grid,
.hero-facts {
  display: flex;
  flex-wrap: wrap;
}

.hero-actions {
  gap: 16px;
  margin-top: 36px;
}

.button {
  display: inline-flex;
  min-height: 52px;
  align-items: center;
  justify-content: center;
  border-radius: 999px;
  padding: 14px 24px;
  border: 2px solid transparent;
  font-weight: 850;
  cursor: pointer;
}

.button.primary {
  background: var(--sand);
  color: var(--deep);
}

.button.secondary {
  border-color: rgba(255, 255, 255, 0.82);
  color: var(--white);
}

.hero-facts {
  gap: 28px;
  margin: 46px 0 0;
  padding: 0;
}

.hero-facts div {
  min-width: 230px;
  padding-left: 18px;
  border-left: 3px solid var(--teal);
}

.hero-facts dt {
  color: rgba(255, 255, 255, 0.66);
  font-weight: 800;
  text-transform: uppercase;
}

.hero-facts dd {
  margin: 3px 0 0;
  color: var(--white);
  font-size: 1.05rem;
  font-weight: 800;
}

.quick-panel {
  margin-top: -22px;
  position: relative;
  z-index: 3;
}

.quick-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) 440px;
  gap: 34px;
  align-items: stretch;
  padding: 44px;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.intro-copy h2,
.section-heading h2,
.submission-grid h2,
.publication-note h2,
.program-grid h2,
.venue-copy h2,
.contact-grid h2 {
  margin: 0;
  color: var(--ink);
  font-size: 2rem;
  line-height: 1.2;
}

.intro-copy p:last-child,
.publication-note p,
.venue-copy p {
  max-width: 650px;
  color: var(--muted);
  font-size: 1.05rem;
}

.countdown {
  background: var(--navy);
  color: var(--white);
  padding: 26px;
  border-radius: 8px;
}

.countdown-title {
  margin-bottom: 18px;
  color: rgba(255, 255, 255, 0.76);
  font-weight: 800;
}

.timer {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
}

.timer div {
  min-width: 78px;
  min-height: 92px;
  display: grid;
  place-items: center;
  padding: 12px 8px;
  border: 1px solid rgba(255, 255, 255, 0.16);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.08);
}

.timer strong {
  font-size: 1.75rem;
  line-height: 1;
}

.timer span {
  color: rgba(255, 255, 255, 0.74);
  font-size: 0.78rem;
  font-weight: 900;
  text-transform: uppercase;
}

.submission-band {
  margin-top: 74px;
  background: var(--mist);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.submission-grid {
  display: grid;
  grid-template-columns: 330px 1fr;
  gap: 34px;
  align-items: center;
  padding: 42px 0;
}

.deadline-strip {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
}

.deadline-strip div {
  min-height: 112px;
  padding: 18px;
  border-radius: 8px;
  background: var(--white);
  border: 1px solid var(--line);
}

.deadline-strip span {
  display: block;
  color: var(--muted);
  font-weight: 800;
}

.deadline-strip strong {
  display: block;
  margin-top: 10px;
  color: var(--ink);
  font-size: 1.2rem;
}

.deadline-strip .highlight {
  background: var(--deep);
  border-color: var(--deep);
  color: var(--white);
}

.deadline-strip .highlight span,
.deadline-strip .highlight strong {
  color: var(--white);
}

.section {
  padding: 88px 0;
}

.split-layout,
.venue-layout,
.contact-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 420px;
  gap: 72px;
  align-items: start;
}

.timeline {
  position: relative;
  display: grid;
  gap: 30px;
  padding-left: 36px;
}

.timeline::before {
  content: "";
  position: absolute;
  top: 8px;
  bottom: 8px;
  left: 11px;
  width: 3px;
  background: linear-gradient(var(--ocean), var(--sand));
}

.timeline article {
  position: relative;
}

.timeline article::before {
  content: "";
  position: absolute;
  left: -36px;
  top: 5px;
  width: 21px;
  height: 21px;
  border: 5px solid var(--ocean);
  border-radius: 50%;
  background: var(--paper);
}

.timeline time {
  color: var(--ocean);
  font-size: 1.1rem;
  font-weight: 900;
}

.timeline h3,
.topic-list h3,
.venue-list strong,
.program-row h3,
.committee-grid h3 {
  margin: 4px 0;
  color: var(--ink);
  font-size: 1.1rem;
  line-height: 1.3;
}

.timeline p,
.topic-list p,
.topic-clusters p,
.program-row p,
.committee-grid p {
  margin: 0;
  color: var(--muted);
}

.publication-note {
  position: sticky;
  top: 132px;
  padding: 34px;
  border-radius: 8px;
  background: var(--white);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.status-section {
  padding: 56px 0;
}

.status-card {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
  padding: 32px;
  background: var(--white);
  border: 1px solid var(--line);
  border-left: 5px solid var(--ocean);
  border-radius: 8px;
  box-shadow: 0 14px 34px rgba(8, 35, 53, 0.07);
}

.status-card h2 {
  margin: 0;
  color: var(--ink);
  font-size: 1.75rem;
  line-height: 1.25;
}

.status-card p:last-child {
  max-width: 720px;
  margin: 10px 0 0;
  color: var(--muted);
}

.registration-status {
  background: var(--white);
}

.text-link {
  display: inline-flex;
  margin-top: 8px;
  color: var(--ocean);
  font-weight: 900;
  border-bottom: 2px solid var(--sand);
}

.topics-section {
  background: var(--white);
}

.section-heading {
  max-width: 740px;
  margin: 0 auto 38px;
  text-align: center;
}

.topic-clusters {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
  margin-bottom: 22px;
}

.topic-clusters article {
  min-height: 202px;
  padding: 28px;
  border-radius: 8px;
  color: var(--white);
  background: var(--navy);
  position: relative;
  overflow: hidden;
}

.topic-clusters article:nth-child(2) {
  background: var(--ocean);
}

.topic-clusters article:nth-child(3) {
  background: var(--coral);
}

.topic-clusters span {
  display: inline-grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.16);
  font-weight: 900;
}

.topic-clusters h3 {
  margin: 22px 0 8px;
  font-size: 1.25rem;
}

.topic-clusters p {
  color: rgba(255, 255, 255, 0.82);
}

.topic-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}

.topic-list article {
  min-height: 138px;
  display: grid;
  grid-template-columns: 48px 1fr;
  gap: 18px;
  align-items: start;
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #f7fbfc;
}

.topic-list strong {
  display: inline-grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: var(--navy);
  color: var(--white);
}

.program-section {
  background:
    linear-gradient(180deg, rgba(237, 247, 248, 0.84), rgba(251, 251, 248, 1)),
    var(--mist);
}

.program-grid {
  display: grid;
  grid-template-columns: 310px 1fr;
  gap: 48px;
}

.program-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.program-row article,
.committee-grid article,
.announcement,
.enquiry-form {
  padding: 26px;
  border-radius: 8px;
  background: var(--white);
  border: 1px solid var(--line);
  box-shadow: 0 14px 34px rgba(8, 35, 53, 0.07);
}

.program-row span,
.committee-grid span {
  display: inline-block;
  margin-bottom: 13px;
  color: var(--ocean);
  font-weight: 900;
  text-transform: uppercase;
}

.venue-section {
  background: var(--paper);
}

.venue-layout {
  grid-template-columns: minmax(0, 0.88fr) minmax(420px, 1fr);
  align-items: center;
}

.venue-list {
  display: grid;
  gap: 14px;
  padding: 0;
  margin: 30px 0 0;
  list-style: none;
}

.venue-list li {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
}

.venue-list span {
  color: var(--muted);
  text-align: right;
}

.venue-visual {
  margin: 0;
  border-radius: 8px;
  overflow: hidden;
  background: var(--navy);
  box-shadow: var(--shadow);
}

.venue-visual img {
  width: 100%;
  height: 390px;
  object-fit: cover;
}

.venue-visual figcaption {
  padding: 17px 22px;
  color: var(--white);
  font-weight: 850;
}

.committees-section {
  background: var(--white);
}

.committee-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}

.committee-grid article {
  min-height: 190px;
}

.announcement {
  display: grid;
  grid-template-columns: 300px 1fr;
  gap: 24px;
  align-items: center;
  margin-top: 20px;
  background: var(--mist);
  border-left: 5px solid var(--ocean);
}

.announcement strong {
  color: var(--navy);
  font-size: 1.08rem;
}

.announcement p {
  margin: 0;
  color: var(--muted);
}

.contact-section {
  background: var(--mist);
}

.contact-list {
  display: grid;
  gap: 14px;
  margin-top: 28px;
}

.contact-list p {
  display: grid;
  grid-template-columns: 190px 1fr;
  gap: 16px;
  margin: 0;
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
}

.contact-list strong {
  color: var(--navy);
}

.contact-list a {
  color: var(--ocean);
  font-weight: 800;
}

.enquiry-form {
  display: grid;
  gap: 16px;
  box-shadow: none;
}

.enquiry-form fieldset {
  display: grid;
  gap: 16px;
  min-width: 0;
  margin: 0;
  padding: 0;
  border: 0;
}

.form-note {
  margin: 0;
  padding: 14px 16px;
  border-left: 4px solid var(--ocean);
  border-radius: 8px;
  background: var(--mist);
  color: var(--muted);
}

.enquiry-form.is-disabled input,
.enquiry-form.is-disabled textarea {
  background: #f6fafb;
  color: #72828f;
}

.enquiry-form label {
  display: grid;
  gap: 8px;
  color: var(--navy);
  font-weight: 850;
}

.enquiry-form input,
.enquiry-form textarea {
  width: 100%;
  border: 1px solid #c9dce3;
  border-radius: 8px;
  padding: 12px 14px;
  color: var(--ink);
  font: inherit;
  background: var(--white);
}

.enquiry-form textarea {
  resize: vertical;
}

.site-footer {
  background: var(--deep);
  color: var(--white);
  padding: 34px 0;
}

.notice-modal {
  position: fixed;
  inset: 0;
  z-index: 50;
  display: grid;
  place-items: center;
  padding: 24px;
  background: rgba(7, 30, 43, 0.42);
}

.notice-modal[hidden] {
  display: none;
}

.notice-dialog {
  position: relative;
  width: min(420px, 100%);
  padding: 30px;
  border-radius: 8px;
  background: var(--white);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.notice-dialog h2 {
  margin: 0;
  color: var(--ink);
  font-size: 1.45rem;
  line-height: 1.25;
}

.notice-dialog p:last-child {
  margin: 10px 0 0;
  color: var(--muted);
}

.notice-close {
  position: absolute;
  top: 12px;
  right: 12px;
  width: 34px;
  height: 34px;
  border: 1px solid var(--line);
  border-radius: 50%;
  background: var(--white);
  color: var(--ink);
  font-size: 1.35rem;
  line-height: 1;
  cursor: pointer;
}

.not-found-page {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 24px;
  background:
    linear-gradient(135deg, rgba(237, 247, 248, 0.92), rgba(251, 251, 248, 1)),
    var(--paper);
}

.not-found-card {
  width: min(520px, 100%);
  padding: 40px;
  border-radius: 8px;
  background: var(--white);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
  text-align: center;
}

.not-found-card h1 {
  margin: 0 0 22px;
  color: var(--ink);
  font-size: 2.25rem;
  line-height: 1.15;
}

.not-found-card p:not(.section-kicker) {
  margin: -10px 0 24px;
  color: var(--muted);
}

.footer-grid {
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.footer-grid p {
  margin: 4px 0 0;
  color: rgba(255, 255, 255, 0.7);
}

.footer-grid div:last-child {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  color: rgba(255, 255, 255, 0.8);
  font-weight: 750;
}

@media (max-width: 1180px) {
  .main-nav {
    min-height: 76px;
  }

  .nav-toggle {
    display: block;
  }

  .nav-links {
    position: absolute;
    top: 110px;
    left: 24px;
    right: 24px;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 6px;
    padding: 18px;
    background: var(--white);
    border: 1px solid var(--line);
    border-radius: 8px;
    box-shadow: var(--shadow);
  }

  .nav-links.open {
    display: flex;
  }

  .nav-cta {
    text-align: center;
  }

  .quick-grid,
  .submission-grid,
  .split-layout,
  .status-card,
  .program-grid,
  .venue-layout,
  .contact-grid {
    grid-template-columns: 1fr;
  }

  .publication-note {
    position: static;
  }

  .deadline-strip,
  .topic-clusters,
  .program-row,
  .committee-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .venue-layout {
    gap: 36px;
  }
}

@media (max-width: 720px) {
  .utility-inner,
  .main-nav,
  .section-inner,
  .hero-content {
    width: min(100% - 32px, 1200px);
  }

  .utility-inner {
    justify-content: space-between;
  }

  .brand {
    min-width: 0;
  }

  .wave-brand img {
    width: 186px;
    height: 54px;
  }

  .hero {
    min-height: 720px;
  }

  .hero-content {
    padding: 64px 0 104px;
  }

  .hero h1 {
    font-size: 3.1rem;
  }

  .theme {
    font-size: 1.55rem;
  }

  .hero-copy {
    font-size: 1rem;
  }

  .hero-facts {
    gap: 18px;
  }

  .hero-facts div {
    min-width: 100%;
  }

  .quick-grid {
    padding: 24px;
  }

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

  .deadline-strip,
  .topic-clusters,
  .topic-list,
  .program-row,
  .committee-grid,
  .announcement {
    grid-template-columns: 1fr;
  }

  .topic-list article {
    grid-template-columns: 42px 1fr;
    padding: 20px;
  }

  .venue-list li,
  .contact-list p {
    display: grid;
    grid-template-columns: 1fr;
    gap: 4px;
  }

  .venue-list span {
    text-align: left;
  }

  .section {
    padding: 64px 0;
  }

  .venue-visual img {
    height: 270px;
  }
}