/* Visual reference: https://llm4hr.github.io/ — lightweight implementation. */
:root {
  color-scheme: light;
  --blue: #3a5199;
  --blue-light: #5c85d6;
  --link: #307cc8;
  --ink: #333;
  --tint: #f8f9fa;
  --line: #e9ecef;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 85px; }
body {
  margin: 0;
  color: var(--ink);
  background: #fff;
  font-family: "Source Sans Pro", "Helvetica Neue", Helvetica, Arial, sans-serif;
  font-size: 16px;
  font-weight: 300;
  line-height: 1.72222;
}
a { color: var(--link); text-decoration: none; }
a:hover { color: var(--blue); text-decoration: underline; }
a, button, summary { -webkit-tap-highlight-color: transparent; }
:focus-visible { outline: 3px solid var(--blue-light); outline-offset: 5px; }
img { display: block; max-width: 100%; }
p { margin: 0 0 20px; }
strong { font-weight: 700; }
h1, h2, h3 { line-height: 1.1; }
h3 { margin: 30px 0 12px; font-size: 28px; font-weight: 700; }
.container { width: 100%; padding: 0 15px; margin: 0 auto; }
.skip-link { position: fixed; top: 8px; left: 12px; z-index: 100; padding: 10px 16px; background: #fff; transform: translateY(-160%); }
.skip-link:focus { transform: translateY(0); }

/* Compact cityscape masthead, followed by a white sticky navigation bar. */
.intro-header {
  background-color: #7650b6;
  background-image: linear-gradient(rgba(147, 112, 219, .85), rgba(103, 65, 180, .92)), url("assets/montreal-skyline.jpg");
  background-position: center, center 56%;
  background-size: cover;
  padding: 45px 0 24px;
  text-align: center;
}
.hero-content { width: 100%; }
.intro-header h1 {
  margin: 0 0 10px;
  color: #fff;
  font-family: Montserrat, sans-serif;
  font-size: 28.8px;
  font-weight: 700;
  letter-spacing: 1px;
  text-shadow: 2px 2px 4px rgba(0, 0, 0, .5);
}
.hero-date { margin: 8px 0 0; color: #d0e0ff; font-size: 16px; line-height: 1.1; letter-spacing: 2px; text-transform: uppercase; }
.site-header { position: sticky; top: 0; z-index: 20; background: #fff; box-shadow: 0 2px 10px rgba(0, 0, 0, .1); }
.header-inner { display: flex; align-items: center; justify-content: space-between; min-height: 62px; gap: 18px; }
.brand { color: var(--blue); font-family: Montserrat, sans-serif; font-size: 24px; font-weight: 400; letter-spacing: 2px; line-height: 1.1; white-space: nowrap; padding: 18px 15px; }
.brand:hover { color: var(--blue); text-decoration: none; }
.site-nav { display: flex; align-items: center; gap: 0; }
.site-nav a { color: #555; font-weight: 400; letter-spacing: .5px; padding: 18px 13px; white-space: nowrap; }
.site-nav a:hover, .site-nav a:focus-visible { color: var(--blue); text-decoration: none; background: var(--tint); }
.menu-toggle { display: none; }

/* Match the reference's section spacing, blue headings, and underline. */
.content-section { padding: 70px 0; }
.section-tint { background: var(--tint); }
.section-heading { position: relative; margin: 30px 0 25px; padding-bottom: 15px; color: var(--blue); font-family: Montserrat, sans-serif; font-size: 30px; font-weight: 700; }
.section-heading::after { content: ""; position: absolute; bottom: 0; left: 0; width: 80px; height: 3px; background: var(--blue-light); }
.lead { font-size: 17px; font-weight: 300; line-height: 1.85; margin-bottom: 20px; }
.topics-list, .contribution-list { margin: 0; padding-left: 25px; }
.topics-list li, .contribution-list li { padding: 8px 0; font-size: 16px; }
.topics-list li::marker, .contribution-list li::marker { color: var(--blue); font-size: 20px; }
.contribution-list { margin-bottom: 20px; }

/* Dates and program tables share the same full-width striped treatment. */
.data-table { width: 100%; border-collapse: collapse; line-height: 2; margin-bottom: 40px; border-radius: 8px; overflow: hidden; box-shadow: 0 2px 8px rgba(0, 0, 0, .1); }
.data-table th, .data-table td { padding: 15px; text-align: left; vertical-align: top; border-bottom: 1px solid var(--line); }
.data-table th { color: #fff; background: var(--blue); font-weight: 600; letter-spacing: .5px; }
.data-table tbody tr:nth-child(odd) { background: #f2f2f2; }
.data-table tbody tr:hover { background: #e9ecef; }
.data-table th:first-child, .data-table td:first-child { width: 35%; }
.highlight-row td:first-child { font-weight: 700; color: var(--blue); }
.dates-note { font-size: 15px; }
.submission-wrap { text-align: center; margin: 35px 0 40px; }
.submission-notice { display: inline-block; margin: 0; padding: 12px 28px; color: #fff; background: var(--blue); border-radius: 30px; font-weight: 400; box-shadow: 0 4px 10px rgba(58, 81, 153, .3); }
.schedule-panel { padding: 30px; background: #fff; border-radius: 8px; box-shadow: 0 2px 8px rgba(0, 0, 0, .1); }
.schedule-panel p:last-child { margin-bottom: 0; }

/* Linked names above portrait frames, with affiliations beneath them. */
.chairs-grid, .students-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 30px; margin: 0; padding: 0; list-style: none; }
.person-card { padding: 10px 0; text-align: center; transition: transform .3s ease, box-shadow .3s ease; }
.person-card:hover { transform: translateY(-5px); box-shadow: 0 10px 25px rgba(0, 0, 0, .15); }
.person-card h3 { margin: 0 0 16px; font-size: 20px; line-height: 1.1; }
.person-card h3 a { color: var(--blue); }
.portrait-link { display: block; width: 130px; height: 174px; margin: 0 auto 12px; border: 4px solid var(--tint); border-radius: 50%; overflow: hidden; box-shadow: 0 0 15px rgba(0, 0, 0, .1); transition: transform .3s ease; }
.portrait-link:hover { transform: scale(1.05); }
.person-portrait { width: 100%; height: 100%; object-fit: cover; }
.portrait-zhong { object-position: 50% 8%; }
.portrait-chen { object-position: 50% 12%; }
.portrait-hao { object-position: 50% 12%; }
.portrait-zihan { object-position: 50% 18%; }
.portrait-dong { transform: scale(1.55); transform-origin: 62% 38%; }
.person-institution { margin: 0 0 12px; font-size: 15px; font-weight: 700; line-height: 1.45; }
.person-institution a { color: var(--blue); }
.person-department { color: #666; font-size: 13px; font-weight: 300; margin: 0; }
.organizers-panel { margin-top: 30px; padding: 70px 15px 35px; background: #fff; }
.students-grid .portrait-link { width: 130px; height: 130px; }

.faq-list details { border-bottom: 1px solid var(--line); padding: 18px 0; }
.faq-list summary { color: var(--blue); font-size: 18px; font-weight: 600; cursor: pointer; }
.faq-list details p { margin: 16px 0 0; font-size: 17px; line-height: 1.85; }
.contact-section { margin-top: 40px; }
.contact-section h3 { color: var(--blue); font-size: 24px; }
.contact-section a { overflow-wrap: anywhere; }
.site-footer { padding: 25px 0; background: var(--blue); color: #fff; text-align: center; }
.site-footer p { font-weight: 300; letter-spacing: 1px; margin-bottom: 10px; }
.site-footer nav { display: flex; justify-content: center; flex-wrap: wrap; gap: 8px 24px; }
.site-footer a { color: #fff; font-size: 14px; }

@media (min-width: 768px) { .container { width: 750px; } .hero-content { width: 100%; } }
@media (min-width: 992px) { .container { width: 970px; } .hero-content { width: 100%; } .brand { font-size: 20px; padding-left: 0; } .site-nav a { padding-right: 9px; padding-left: 9px; } }
@media (min-width: 1200px) { .container { width: 1170px; } .hero-content { width: 100%; } .brand { font-size: 24px; padding-left: 15px; } .site-nav a { padding-right: 13px; padding-left: 13px; } }

@media (max-width: 991px) {
  html { scroll-padding-top: 80px; }
  .header-inner { flex-wrap: wrap; gap: 0; }
  .brand { padding-left: 0; font-size: 20px; letter-spacing: 1px; }
  .site-nav { width: 100%; flex-wrap: wrap; padding-bottom: 10px; }
  .site-nav a { padding: 10px 12px; }
  .js .menu-toggle { display: flex; align-items: center; gap: 10px; padding: 8px 10px; border: 1px solid #ddd; border-radius: 4px; background: #fff; color: #555; font: inherit; font-weight: 400; cursor: pointer; }
  .menu-icon { width: 17px; height: 12px; border-top: 2px solid currentColor; border-bottom: 2px solid currentColor; position: relative; }
  .menu-icon::after { content: ""; position: absolute; left: 0; right: 0; top: 3px; border-top: 2px solid currentColor; }
  .js .site-nav { display: none; }
  .js .site-nav.is-open { display: flex; }
  .chairs-grid, .students-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); row-gap: 35px; }
}

@media (max-width: 575px) {
  .intro-header { padding: 32px 0 26px; }
  .intro-header h1 { font-size: 22px; line-height: 1.25; letter-spacing: .35px; }
  .hero-date { font-size: 12px; line-height: 1.7; letter-spacing: 1px; margin-top: 14px; }
  .brand { font-size: 17px; letter-spacing: .5px; }
  .site-nav { flex-direction: column; align-items: stretch; max-height: 70vh; overflow-y: auto; }
  .content-section { padding: 40px 0; }
  .section-heading { font-size: 25px; line-height: 1.2; margin-top: 20px; }
  .lead { font-size: 16px; line-height: 1.8; }
  .data-table { line-height: 1.6; font-size: 15px; }
  .data-table th, .data-table td { padding: 12px 10px; }
  .data-table th:first-child, .data-table td:first-child { width: 37%; }
  .schedule-panel { padding: 20px; }
  .schedule-panel h3 { font-size: 24px; margin-top: 12px; }
  .chairs-grid, .students-grid { gap: 30px 18px; }
  .person-card h3 { font-size: 19px; }
  .portrait-link { width: 120px; height: 160px; }
  .students-grid .portrait-link { width: 120px; height: 120px; }
  .person-institution { font-size: 14px; }
  .organizers-panel { padding: 35px 0 20px; }
  .site-footer p { font-size: 14px; }
}
@media (max-width: 360px) {
  .brand { font-size: 14px; letter-spacing: .25px; }
  .js .menu-toggle { font-size: 14px; padding: 7px 8px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; }
}
@media print {
  html { scroll-behavior: auto; }
  body { color: #000; font-size: 11pt; }
  .container { width: 100%; }
  .site-header, .skip-link, .submission-wrap, .site-footer nav { display: none; }
  .intro-header { background: #fff; padding: 20px 0; }
  .intro-header h1, .hero-date { color: #000; text-shadow: none; }
  .content-section, .organizers-panel { padding: 20px 0; background: #fff; }
  .section-heading { font-size: 20pt; }
  .chairs-grid, .students-grid { grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 15px; }
  .data-table, .schedule-panel { box-shadow: none; }
  .data-table th { color: #000; background: #eee; }
  .person-card, tr { break-inside: avoid; }
  .site-footer { background: #fff; color: #000; }
}