/* Final presentation layer for the existing static homepage. */
:root {
  --primary-color: #355c7d;
  --primary-dark: #26445e;
  --primary-light: #355c7d;
  --primary-rgb: 53, 92, 125;
  --secondary-color: var(--primary-color);
  --accent-color: var(--text-secondary);
  --action-background: #355c7d;
  --action-hover: #26445e;
  --action-text: #ffffff;
  --bg-primary: #ffffff;
  --bg-secondary: #f7f8fa;
  --bg-tertiary: #edf2f6;
  --text-primary: #1f2933;
  --text-secondary: #526171;
  --text-tertiary: #607080;
  --border-color: #d9e1e8;
  --success-color: var(--primary-color);
  --success-light: var(--bg-tertiary);
  --success-dark: var(--primary-dark);
  --sidebar-width: 264px;
  --max-content-width: 1140px;
  --shadow-sm: 0 1px 3px rgba(25, 39, 56, .04);
  --shadow-md: 0 3px 14px rgba(25, 39, 56, .045);
  --shadow-lg: 0 6px 24px rgba(25, 39, 56, .075);
}

[data-theme="dark"] {
  color-scheme: dark;
  --primary-color: #9ab7d3;
  --primary-dark: #bdd0e2;
  --primary-light: #9ab7d3;
  --primary-rgb: 154, 183, 211;
  --action-background: #9ab7d3;
  --action-hover: #bdd0e2;
  --action-text: #121b27;
  --bg-primary: #1a2635;
  --bg-secondary: #121b27;
  --bg-tertiary: #243244;
  --text-primary: #e4eaf0;
  --text-secondary: #b4c0ce;
  --text-tertiary: #94a3b4;
  --border-color: #344658;
}

html { scroll-padding-top: 32px; }
body { line-height: 1.7; }
.language-toggle {
  position: fixed; top: 17px; right: 72px; z-index: 1001;
  min-width: 52px; height: 42px; padding: 0 12px;
  color: var(--text-primary); background: var(--bg-primary);
  border: 1px solid var(--border-color); border-radius: 24px;
  box-shadow: var(--shadow-sm); font-size: .8rem; font-weight: 600;
}
.language-toggle:hover { border-color: var(--primary-color); }
img { max-width: 100%; }
button, input, select, textarea { font: inherit; }
a { text-underline-offset: .2em; }
[data-theme="dark"] a { color: var(--primary-color); }
[data-theme="dark"] a:hover { color: var(--primary-dark); }
[data-theme="dark"] :is(code, pre, table, input, textarea, select) { color: var(--text-primary); background-color: var(--bg-primary); border-color: var(--border-color); }
[data-theme="dark"] th { color: var(--text-primary); background: var(--bg-tertiary); border-color: var(--border-color); }
[data-theme="dark"] td { color: var(--text-secondary); border-color: var(--border-color); }

/* Keep keyboard navigation visible, including the dynamically rendered UI. */
:where(a, button, input, select, textarea, [tabindex]):focus-visible {
  outline: 3px solid var(--primary-color);
  outline-offset: 4px;
}

.skip-link {
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 10000;
  padding: 10px 18px;
  border-radius: 6px;
  color: var(--text-primary);
  background: var(--bg-primary);
  box-shadow: var(--shadow-lg);
  transform: translateY(-160%);
}
.skip-link:focus { transform: none; }

/* A quieter, compact profile leaves more navigation in view. */
#sidebar, [data-theme="dark"] #sidebar {
  background: #182d49;
  border-right: 1px solid rgba(255, 255, 255, .08);
  height: 100dvh;
  overscroll-behavior: contain;
  scrollbar-color: #63748b #182d49;
}
#sidebar .sidebar-content { padding: 30px 20px 24px; }
#sidebar .profile { margin-bottom: 20px; }
#sidebar .profile-image {
  width: 112px;
  height: 112px;
  border: 3px solid rgba(255, 255, 255, .2);
  margin-bottom: 16px;
}
#sidebar .profile-name { color: #fff; letter-spacing: -.02em; }
#sidebar div.profile-name { font-size: 1rem; font-weight: 500; letter-spacing: .12em; }
#sidebar .profile-name[lang="zh-CN"] { font-size: 1rem; font-weight: 500; letter-spacing: .12em; }
#sidebar .profile-title { margin-bottom: 3px; color: #d1dbe5; opacity: 1; font-size: .81rem; }
#sidebar .profile-role { margin: 10px 0 0; color: #b4c0ce; font-size: .8rem; }
#sidebar .contact-info, [data-theme="dark"] #sidebar .contact-info {
  padding: 8px 10px;
  margin: 14px 0;
  background: rgba(255, 255, 255, .045);
  border: 1px solid rgba(255, 255, 255, .1);
  backdrop-filter: none;
}
#sidebar .contact-info-item { padding: 5px 0; font-size: .75rem; }
#sidebar .contact-info-item i { width: 14px; flex-shrink: 0; }
#sidebar .cv-downloads { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 8px; margin: 12px 0; }
#sidebar .cv-download {
  padding: 10px 4px;
  border-width: 1px;
  background: rgba(255, 255, 255, .07);
  font-size: .76rem;
  font-weight: 500;
  white-space: nowrap;
}
#sidebar .cv-download i { margin-right: 4px; }
#sidebar .social-links-grid { grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 7px; margin: 12px 0; }
#sidebar .social-link { min-height: 40px; height: 40px; aspect-ratio: auto; font-size: 1rem; }
#sidebar .social-link::after { z-index: 10; }
#sidebar .sidebar-divider { margin: 16px 0; background: rgba(255, 255, 255, .12); }
#sidebar .navigation { margin-top: 14px; }
#sidebar .nav-item { min-height: 40px; padding: 8px 12px; margin-bottom: 3px; font-size: .85rem; }
#sidebar .nav-item.active, [data-theme="dark"] #sidebar .nav-item.active {
  background: rgba(255, 255, 255, .12);
  box-shadow: inset 3px 0 #9ab7d3;
  color: #fff;
}
#sidebar .nav-icon { font-size: .9rem; width: 18px; text-align: center; opacity: .8; }
#sidebar :is(.profile-image, .contact-info-item, .cv-download, .social-link, .nav-item):hover { transform: none; box-shadow: none; }
#sidebar :where(a, button):focus-visible { outline-color: #9ab7d3; }

/* Page rhythm and a distinct introduction, retaining every content module. */
#main, [data-theme="dark"] #main { min-width: 0; background: var(--bg-secondary); transition: background-color var(--transition-base); }
#main .main-container { padding: 54px 48px 32px; }
#main section { margin: 0 0 56px; scroll-margin-top: 30px; }
#main section + section { margin-top: 0; }
#main .section-header { padding-bottom: 14px; margin-bottom: 24px; border-bottom: 1px solid var(--border-color); }
#main .section-title { font-size: 1.65rem; letter-spacing: -.035em; line-height: 1.3; margin-bottom: 6px; }
#main .section-subtitle { font-size: .95rem; line-height: 1.6; margin-bottom: 0; color: var(--text-tertiary); }
#main #about .section-title { font-size: clamp(2rem, 3.8vw, 3rem); letter-spacing: -.05em; }
#main #about > .card { padding: 28px 30px; border-top: 3px solid var(--primary-color); }
#main #about .card-content { font-size: .97rem; }
#main .card, [data-theme="dark"] #main .card {
  min-width: 0;
  padding: 24px;
  margin-bottom: 20px;
  color: var(--text-primary);
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  box-shadow: var(--shadow-sm);
}
#main .card:hover { transform: none; box-shadow: var(--shadow-sm); border-color: var(--border-color); }
#main .card-content { color: var(--text-secondary); line-height: 1.8; }
#main .card-content p:last-child { margin-bottom: 0; }
#main .card-content a:not(.btn), #main .timeline-content a { text-decoration: underline; text-decoration-thickness: 1px; }
#main .card-title, #main .project-title { font-size: 1.12rem; line-height: 1.5; letter-spacing: -.02em; }
#main .research-interests h4 { font-size: .82rem; letter-spacing: .055em; text-transform: uppercase; margin-bottom: 12px; }
#main .research-interests h3 { font-size: .82rem; letter-spacing: .055em; text-transform: uppercase; margin: 20px 0 12px; }
#main .hero-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 20px; }
#main .page-eyebrow { color: var(--text-tertiary); font-size: .8rem; letter-spacing: .05em; margin-bottom: 10px; }
#main .badges-container, #main .project-tags { display: flex; flex-wrap: wrap; gap: 6px; }
#main .badge {
  padding: 5px 9px;
  margin: 0;
  font-size: .72rem;
  line-height: 1.4;
  font-weight: 500;
  white-space: normal;
  color: var(--text-secondary);
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: 5px;
}
#main .mission-statement { padding: 14px 18px; background: var(--bg-secondary); border-left: 2px solid var(--primary-color); font-size: .9rem; }
#main .row { row-gap: 20px; }
#main .research-card { margin-bottom: 0; }
#main .research-card:hover { transform: none; }
#main .research-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 18px; }
#main .research-grid .card { padding: 22px; }
#main .research-grid .card-title { font-size: 1rem; }
#main .research-grid .card-content { font-size: .87rem; }

/* Buttons and filters use solid states, with consistent contrast in both themes. */
#main .btn { gap: 7px; min-height: 38px; font-size: .8rem; padding: 8px 12px; border-radius: 6px; line-height: 1.3; }
#main .btn-outline { color: var(--primary-color); background: transparent; border: 1px solid var(--border-color); }
#main .btn-outline:hover { color: var(--primary-dark); background: var(--bg-tertiary); border-color: var(--primary-color); }
#main .btn-primary { color: var(--action-text); background: var(--action-background); border: 1px solid var(--action-background); }
#main .btn-primary:hover { color: var(--action-text); background: var(--action-hover); border-color: var(--action-hover); transform: none; box-shadow: none; }
#main .filter-buttons, #main .year-filter { justify-content: flex-start; gap: 7px; margin-bottom: 24px; }
#main .filter-btn, #main .year-badge {
  min-height: 38px;
  padding: 8px 13px;
  font-size: .79rem;
  font-weight: 500;
  color: var(--text-secondary);
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: 6px;
}
#main .filter-btn::before, #main .year-badge::before { display: none; }
#main .filter-btn:hover, #main .year-badge:hover { background: var(--bg-tertiary); color: var(--text-primary); transform: none; }
#main .filter-btn.active, #main .year-badge.active { background: var(--action-background); border-color: var(--action-background); color: var(--action-text); transform: none; }

/* News remains a timeline, with dates and headlines legible at a glance. */
#main .timeline { padding-left: 22px; }
#main .timeline::before { width: 1px; background: var(--border-color); }
#main .timeline-item { padding: 18px 22px; margin-bottom: 12px; }
#main .timeline-item::before { top: 25px; left: -28px; width: 10px; height: 10px; background: var(--primary-color); border-color: var(--bg-primary); box-shadow: 0 0 0 4px var(--bg-secondary); }
#main .timeline-date { margin-bottom: 7px; }
#main .timeline-date .badge { padding: 0; background: transparent; border: 0; color: var(--primary-color); font-size: .77rem; font-weight: 600; }
#main .timeline-content h4 { font-size: 1rem; line-height: 1.5; margin-bottom: 5px; }
#main .timeline-content p { color: var(--text-secondary); font-size: .88rem; margin-bottom: 0; }

/* Preserve complete research figures instead of cropping them as photos. */
#main .projects-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 20px; margin-bottom: 0; align-items: start; }
#main .project-card { padding: 0; margin-bottom: 0; height: 100%; }
#main .project-card::before { display: none; }
#main .project-image { height: 190px; margin: 0; padding: 18px; background: #fff; border-radius: 9px 9px 0 0; border-bottom: 1px solid var(--border-color); }
#main .project-image img { object-fit: contain; }
#main .project-card:hover .project-image img { transform: none; }
#main .project-content { padding: 22px; }
#main .project-description { color: var(--text-secondary); font-size: .86rem; line-height: 1.75; }
#main .project-links { gap: 7px; }
#main .expand-project-btn { margin-top: 10px; padding-left: 0; }

/* Publication titles lead; authors and venue form a calmer reading hierarchy. */
#main .publication-year { margin-top: 26px; }
#main .year-header { font-size: 1.12rem; color: var(--text-primary); border-bottom-width: 1px; padding: 10px 0; margin-bottom: 16px; }
#main .year-header .toggle-icon { color: var(--text-tertiary); font-size: .75rem; }
#main .year-toggle { display: flex; align-items: center; justify-content: space-between; width: 100%; padding: 4px 0; border: 0; color: inherit; background: transparent; text-align: left; font: inherit; cursor: pointer; }
#main .year-toggle:hover { color: var(--primary-color); }
#main .year-toggle[aria-expanded="false"] .toggle-icon { transform: rotate(-90deg); }
#main .publication-item { padding: 22px 24px; margin-bottom: 12px; }
#main .publication-item:hover { transform: none; }
#main .publication-title { font-size: 1.06rem; font-weight: 600; line-height: 1.55; letter-spacing: -.012em; margin-bottom: 9px; }
#main .publication-authors { font-size: .82rem; line-height: 1.8; color: var(--text-secondary); }
#main .publication-authors strong { color: var(--text-primary); }
#main .publication-venue { margin-top: 9px; color: var(--primary-color); font-size: .83rem; font-weight: 500; }
#main .publication-venue i { margin-right: 4px; }
#main .publication-note { display: inline-block; font-size: .75rem; }
#main .citation-count { font-size: .76rem; }
#main .publication-links .btn { font-size: .76rem; min-height: 34px; padding: 7px 10px; }

#main .award-item { gap: 20px; align-items: baseline; padding: 13px 0; font-size: .9rem; }
#main .award-year { white-space: nowrap; font-size: .83rem; }
#main .course-header { padding: 0; background: transparent; gap: 12px; cursor: default; }
#main .course-header:hover { color: var(--text-primary); background: transparent; }
#main .course-title { font-size: 1.08rem; line-height: 1.5; margin-bottom: 10px; }
#main .course-info { display: flex; flex-wrap: wrap; column-gap: 20px; font-size: .8rem; }
#main .course-info p { margin-bottom: 10px; }
#main .course-info i { margin-right: 5px; }
#main .course-info i, #main .category-title i, #main .resource-icon { color: var(--primary-color); }
#main .course-description { font-size: .88rem; }
#main details.course-materials { border-top: 1px solid var(--border-color); margin-top: 18px; padding-top: 14px; }
#main .course-materials > summary { padding: 5px 0; color: var(--primary-color); cursor: pointer; font-size: .85rem; font-weight: 500; }
#main .course-materials > summary:focus-visible { outline: 3px solid var(--primary-color); outline-offset: 4px; }
#main .course-materials .materials-grid { margin-top: 12px; display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 8px; }
#main .course-materials .material-item { display: flex; align-items: center; gap: 8px; padding: 11px 12px; margin: 0; border: 1px solid var(--border-color); background: var(--bg-secondary); border-radius: 6px; font-size: .8rem; }
#main .course-materials .material-item:hover { border-color: var(--primary-color); }
#main .talk-item { padding: 20px 22px; border: 1px solid var(--border-color); border-left: 3px solid var(--primary-color); background: var(--bg-primary); }
#main .talk-item:hover { transform: none; box-shadow: none; }
#main .talk-title { font-size: 1.05rem; line-height: 1.5; margin-bottom: 4px; }
#main .talk-type-badge { letter-spacing: .03em; font-size: .64rem; }
#main .category-header { color: var(--text-primary); font-size: 1rem; }
#main .category-header h4 { font-size: 1rem; margin: 0; }
#main .category-header:hover { background: var(--bg-tertiary); color: var(--primary-color); }
#main .resource-items { grid-template-columns: repeat(2, minmax(0, 1fr)); padding: 16px; gap: 10px; background: var(--bg-primary); }
#main .resource-item { min-width: 0; padding: 12px; font-size: .85rem; }
#main .resource-item:hover { transform: none; box-shadow: none; }
#main .resource-item small { display: block; color: var(--text-tertiary); font-size: .76rem; margin-top: 3px; }
#main .resource-icon { object-fit: contain; }
#main .site-footer { padding: 24px 0 8px; border-top: 1px solid var(--border-color); color: var(--text-tertiary); font-size: .78rem; }
#main .text-muted { color: var(--text-tertiary) !important; }

/* Shared introductions and an editorial layout for industry experience. */
#main .page-intro { margin-bottom: 30px; padding-bottom: 22px; border-bottom: 1px solid var(--border-color); }
#main .page-intro h1, #main .page-intro h2 { font-size: clamp(2rem, 3.8vw, 3rem); line-height: 1.2; letter-spacing: -.05em; margin-bottom: 12px; }
#main .page-intro p { max-width: 68ch; margin-bottom: 0; color: var(--text-secondary); font-size: .96rem; }
#main .experience-list { display: grid; gap: 20px; }
#main .experience-card { padding: 26px 28px; background: var(--bg-primary); border: 1px solid var(--border-color); border-radius: 10px; }
#main .experience-card h3 { margin-bottom: 10px; font-size: 1.25rem; letter-spacing: -.025em; line-height: 1.45; }
#main .experience-card h4 { font-size: 1rem; line-height: 1.5; }
#main .experience-meta { display: flex; flex-wrap: wrap; gap: 6px 20px; margin-bottom: 16px; font-size: .82rem; color: var(--text-tertiary); }
#main .experience-card p { font-size: .93rem; color: var(--text-secondary); }
#main .experience-points { margin: 14px 0 0; padding-left: 20px; color: var(--text-secondary); font-size: .91rem; line-height: 1.85; }
#main .experience-points li + li { margin-top: 8px; }
#main .experience-points li::marker { color: var(--primary-color); }

.theme-toggle, .mobile-menu-toggle { width: 42px; height: 42px; border-width: 1px; box-shadow: var(--shadow-md); }
.theme-toggle, .mobile-menu-toggle, [data-theme="dark"] .theme-toggle, [data-theme="dark"] .mobile-menu-toggle { color: var(--text-primary); background: var(--bg-primary); border-color: var(--border-color); }
.theme-toggle { top: 16px; right: 18px; }
.theme-toggle:hover { transform: none; box-shadow: var(--shadow-md); }
.theme-toggle:hover, [data-theme="dark"] .theme-toggle:hover { background: var(--bg-tertiary); border-color: var(--border-color); }
.theme-toggle svg { width: 21px; height: 21px; fill: none; stroke: currentColor; }
[data-theme="dark"] .theme-toggle svg { fill: none; stroke: currentColor; }
.back-to-top { width: 42px; height: 42px; font-size: 15px; box-shadow: var(--shadow-md); }
.back-to-top, [data-theme="dark"] .back-to-top { color: var(--action-text); background: var(--action-background); border-color: var(--action-background); }
.back-to-top:hover, [data-theme="dark"] .back-to-top:hover { color: var(--action-text); transform: none; background: var(--action-hover); border-color: var(--action-hover); }
.scroll-progress { height: 2px; background: var(--primary-color); box-shadow: none; }

/* Content never relies on an entrance animation to become readable. */
#main .animate-on-scroll, #main .stagger-animation > * { opacity: 1; transform: none; animation: none; transition: none; }
#main .section-highlight, [data-theme="dark"] #main .section-highlight { animation: none; }

@media (max-width: 1100px) and (min-width: 769px) {
  :root { --sidebar-width: 240px; }
  #sidebar .sidebar-content { padding: 28px 16px 22px; }
  #main .main-container { padding: 50px 30px 28px; }
  #main .project-content { padding: 18px; }
  #main .research-grid { grid-template-columns: 1fr; }
}

@media (max-width: 900px) and (min-width: 769px) {
  #main .projects-grid, #main .resource-items { grid-template-columns: 1fr; }
  #main #research .col-md-6 { width: 100%; }
}

@media (max-width: 768px) {
  :root { --sidebar-width: 284px; }
  html { scroll-padding-top: 80px; }
  #sidebar { max-width: calc(100vw - 48px); }
  #sidebar .sidebar-content { padding-top: 72px; }
  #main .main-container { padding: 84px 22px 24px; }
  #main section { margin-bottom: 42px; scroll-margin-top: 78px; }
  #main .section-title { font-size: 1.45rem; }
  #main #about .section-title { font-size: 2.15rem; }
  #main .section-header { margin-bottom: 20px; }
  #main .section-subtitle { font-size: .88rem; }
  #main .card, #main #about > .card { padding: 20px; }
  #main #about .card-content { font-size: .9rem; }
  #main .projects-grid { grid-template-columns: 1fr; gap: 18px; }
  #main .project-card { padding: 0; }
  #main .project-image { height: 210px; }
  #main .project-content { padding: 20px; }
  #main .timeline { padding-left: 17px; }
  #main .timeline-item { padding: 16px 18px; }
  #main .timeline-item::before { left: -23px; }
  #main .publication-title { font-size: 1rem; }
  #main .publication-item { padding: 20px; }
  #main .resource-items { grid-template-columns: 1fr; }
  #main .research-grid, #main .course-materials .materials-grid { grid-template-columns: 1fr; }
  #main .btn, #main .filter-btn, #main .year-badge, #main .publication-links .btn { min-height: 42px; }
  #main .course-header { flex-wrap: wrap; justify-content: flex-start; margin-bottom: 10px; }
  #main .course-title { margin-bottom: 0; }
  #main .page-intro { margin-bottom: 24px; }
  #main .experience-card { padding: 20px; }
  .mobile-menu-toggle { top: 16px; left: 18px; }
  .mobile-menu-toggle span { width: 21px; margin: 3px 0; }
  .theme-toggle { right: 18px; }
}

@media (max-width: 380px) {
  #main .main-container { padding-right: 16px; padding-left: 16px; }
  #main .card, #main #about > .card, #main .publication-item { padding: 17px; }
  #main .project-card { padding: 0; }
  #main .project-content { padding: 17px; }
  #main .project-image { height: 180px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; scroll-behavior: auto !important; }
}