:root {
  --ink: #162029;
  --muted: #5f6b76;
  --line: #d8e0e7;
  --bg: #f7f9fb;
  --accent: #176b87;
  --accent-dark: #0f4f64;
  --panel: #ffffff;
  --soft: #eaf4f6;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--bg);
  font-family: "Microsoft YaHei", "Segoe UI", Arial, sans-serif;
  letter-spacing: 0;
  overflow-x: hidden;
}

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

button {
  font: inherit;
}

.hero {
  position: relative;
  min-height: 640px;
  overflow: hidden;
  color: #fff;
  background:
    linear-gradient(90deg, rgba(12, 28, 39, 0.94), rgba(12, 28, 39, 0.7)),
    linear-gradient(135deg, #173f52, #233642 55%, #152129);
}

.ambassador-page {
  background: #f7f9fb;
}

.ambassador-hero {
  min-height: 520px;
  color: #fff;
  background:
    linear-gradient(90deg, rgba(12, 28, 39, 0.94), rgba(12, 28, 39, 0.72)),
    url("./assets/lab/research-optoelectronic-encoding.png") center / cover;
}

.ambassador-hero-inner {
  max-width: 1160px;
  margin: 0 auto;
  padding: 96px 24px 88px;
}

.ambassador-hero-inner h1 {
  max-width: 760px;
  margin-top: 12px;
}

.ambassador-hero-inner p:not(.eyebrow) {
  max-width: 1160px;
  margin-top: 18px;
  color: #e2edf0;
  font-size: 18px;
  line-height: 1.78;
  text-align: justify;
}

#photonic-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  opacity: 0.78;
}

.hero::after {
  content: "";
  position: absolute;
  inset: auto 0 0;
  height: 110px;
  background: linear-gradient(180deg, transparent, rgba(247, 249, 251, 0.96));
  pointer-events: none;
}

.nav,
.hero-inner,
.page-section > * {
  max-width: 1160px;
  margin-inline: auto;
}

.nav {
  position: relative;
  z-index: 2;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 22px 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
}

.brand-mark {
  width: 38px;
  height: 38px;
  display: grid;
  place-items: center;
  border-radius: 8px;
  background: #d6edf2;
  color: var(--accent-dark);
}

.nav-links {
  display: flex;
  gap: 14px;
  color: #dbe8ec;
  font-size: 13px;
}

.nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  border: 1px solid rgba(255, 255, 255, 0.28);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.12);
  cursor: pointer;
}

.nav-toggle span {
  display: block;
  width: 20px;
  height: 2px;
  margin: 5px auto;
  border-radius: 999px;
  background: #fff;
}

.hero-inner {
  position: relative;
  z-index: 1;
  padding: 92px 24px 100px;
}

.hero-school,
.hero-college {
  margin: 0;
  font-weight: 800;
}

.hero-school {
  font-size: 26px;
}

.hero-college {
  margin-top: 6px;
  color: #9fe2ef;
  font-size: 21px;
}

h1,
h2,
h3,
p {
  margin: 0;
}

h1 {
  display: grid;
  gap: 8px;
  max-width: 980px;
  margin-top: 24px;
  color: #fff;
  font-size: 50px;
  line-height: 1.1;
  font-weight: 900;
  text-shadow: 0 12px 34px rgba(0, 0, 0, 0.32);
}

.lead {
  max-width: 760px;
  margin-top: 20px;
  color: #e7f0f3;
  font-size: 22px;
  font-weight: 800;
  line-height: 1.7;
}

.hero-audience {
  max-width: 760px;
  margin-top: 8px;
  color: #d8e7eb;
  font-size: 16px;
  line-height: 1.75;
}

.hero-tags,
.hero-actions,
.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.hero-tags {
  margin-top: 22px;
}

.hero-tags span {
  min-height: 30px;
  padding: 5px 10px;
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.1);
  color: #e8f5f8;
  font-size: 13px;
}

.hero-actions {
  margin-top: 28px;
}

.primary,
.secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  border: 0;
  border-radius: 7px;
  padding: 12px 18px;
  cursor: pointer;
}

.primary {
  background: var(--accent);
  color: #fff;
}

.primary:hover {
  background: var(--accent-dark);
}

.secondary {
  border: 1px solid rgba(255, 255, 255, 0.35);
  background: rgba(255, 255, 255, 0.14);
  color: #fff;
}

.secondary.light {
  border: 0;
  background: #e7ebef;
  color: var(--ink);
}

.page-section {
  padding: 78px 24px;
  background: #fff;
}

.page-section.alt {
  background: #f1f6f8;
}

.section-head {
  margin-bottom: 30px;
}

.section-head p,
.page-section p,
.footer p {
  color: var(--muted);
  line-height: 1.74;
  text-align: justify;
  text-justify: inter-ideograph;
}

.card-head {
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
}

.card-head p + p {
  margin-top: 12px;
}

.eyebrow {
  margin-bottom: 12px;
  color: var(--accent);
  font-size: 13px;
  font-weight: 800;
  text-transform: uppercase;
}

.section-head .eyebrow {
  color: var(--accent);
}

h2 {
  font-size: 30px;
  line-height: 1.2;
}

.section-head h2 + p {
  margin-top: 12px;
}

.research-grid,
.benefit-grid,
.resource-layout,
.referral-grid,
.ambassador-principles,
.privilege-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.research-card,
.card-head,
.intro-strip article,
.benefit-grid article,
.resource-layout article,
.outcome-grid article,
.process-list article,
.referral-grid article,
.ambassador-principles article,
.privilege-grid article,
.apply-card,
.publication-card,
.program-detail,
.program-tabs button,
.reward-table,
.standalone-note,
.faq-list details {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  transition: transform 180ms ease, border-color 180ms ease, box-shadow 180ms ease;
}

.research-card:hover,
.research-card:focus,
.card-head:hover,
.intro-strip article:hover,
.benefit-grid article:hover,
.resource-layout article:hover,
.outcome-grid article:hover,
.process-list article:hover,
.referral-grid article:hover,
.ambassador-principles article:hover,
.privilege-grid article:hover,
.apply-card:hover,
.publication-card:hover,
.program-detail:hover,
.program-tabs button:hover,
.reward-table:hover,
.standalone-note:hover,
.faq-list details:hover {
  transform: translateY(-4px);
  border-color: rgba(23, 107, 135, 0.42);
  box-shadow: 0 16px 34px rgba(22, 32, 41, 0.08);
}

.research-card {
  min-height: 420px;
  overflow: hidden;
  cursor: pointer;
  box-shadow: 0 10px 24px rgba(22, 32, 41, 0.06);
}

.research-card img {
  width: 100%;
  height: 235px;
  display: block;
  object-fit: cover;
  background: #e8eef2;
}

.research-card div {
  padding: 18px;
}

.research-card span {
  display: block;
  margin-bottom: 10px;
  color: var(--accent);
  font-weight: 900;
}

.research-card h3,
.benefit-grid strong {
  margin-bottom: 10px;
  font-size: 20px;
  line-height: 1.35;
}

.research-card p,
.benefit-grid p,
.resource-layout li,
.publication-card li,
.program-detail li,
.program-note,
.faq-list p,
.referral-grid p {
  color: #344054;
  line-height: 1.68;
}

.research-card button {
  margin-top: 16px;
  border: 0;
  border-radius: 6px;
  padding: 9px 12px;
  background: var(--accent);
  color: #fff;
  cursor: pointer;
}

.program-tabs {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 12px;
  margin-bottom: 14px;
}

.program-tabs button {
  min-height: 124px;
  padding: 16px;
  color: var(--ink);
  text-align: left;
  cursor: pointer;
}

.program-tabs button:hover,
.program-tabs button.active {
  border-color: rgba(23, 107, 135, 0.46);
}

.program-tabs button.active {
  outline: 2px solid rgba(23, 107, 135, 0.18);
}

.program-tabs span,
.program-tabs strong,
.program-tabs small {
  display: block;
}

.program-tabs span {
  margin-bottom: 10px;
  font-size: 17px;
  font-weight: 800;
  line-height: 1.35;
}

.program-tabs strong {
  color: var(--accent-dark);
  font-size: 13px;
  line-height: 1.45;
}

.program-tabs small {
  margin-top: 8px;
  color: var(--muted);
  line-height: 1.45;
}

.program-detail {
  padding: 24px;
}

.program-detail-main,
.program-note {
  max-width: none;
}

.program-detail-main span {
  display: inline-flex;
  margin-bottom: 8px;
  color: var(--accent);
  font-size: 13px;
  font-weight: 800;
}

.program-detail-main h3 {
  font-size: 24px;
  line-height: 1.32;
}

.program-stipend {
  max-width: none;
  margin: 16px 0;
  padding: 12px;
  border-left: 4px solid var(--accent);
  background: var(--soft);
  color: var(--accent-dark);
  font-weight: 800;
  line-height: 1.55;
}

.program-detail-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.program-detail ul,
.resource-layout ul,
.publication-card ul {
  display: grid;
  gap: 8px;
  margin: 10px 0 0;
  padding-left: 18px;
}

.program-note {
  margin-top: 12px;
  padding-top: 12px;
  border-top: 1px solid var(--line);
  white-space: pre-line;
  overflow-wrap: anywhere;
}

.benefit-grid article,
.resource-layout article,
.referral-grid article {
  padding: 20px;
}

.benefit-grid strong,
.referral-grid strong,
.ambassador-principles strong,
.privilege-grid h3 {
  display: block;
  color: var(--accent-dark);
}

.ambassador-principles article,
.privilege-grid article {
  padding: 20px;
}

.ambassador-principles {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.ambassador-principles p,
.privilege-grid p {
  color: var(--muted);
  line-height: 1.7;
}

.privilege-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.privilege-grid span {
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  margin-bottom: 14px;
  padding: 4px 10px;
  border-radius: 999px;
  background: #e5f3f6;
  color: var(--accent-dark);
  font-weight: 800;
}

.resource-layout {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.resource-layout h3 {
  margin-bottom: 10px;
  font-size: 18px;
}

.publication-card {
  margin-top: 16px;
  padding: 24px;
}

.outcome-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
}

.outcome-grid article {
  display: grid;
  grid-template-columns: 110px 140px 1fr;
  gap: 14px;
  align-items: center;
  padding: 14px 16px;
}

.outcome-grid strong,
.outcome-grid span,
.outcome-grid p {
  display: block;
  margin: 0;
}

.outcome-grid span {
  color: var(--muted);
  font-size: 13px;
}

.outcome-grid p {
  color: var(--accent-dark);
  font-weight: 800;
}

.apply-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
  align-items: start;
}

.apply-card {
  padding: 22px;
}

.apply-card h3 {
  font-size: 22px;
}

.apply-card p {
  margin-top: 10px;
}

.apply-card .primary,
.apply-card .secondary {
  margin-top: 16px;
  margin-right: 10px;
}

.email-line {
  color: var(--accent-dark) !important;
  font-weight: 900;
}

.process-list {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
}

.intro-strip {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.process-list article,
.intro-strip article {
  min-height: 138px;
  padding: 20px;
}

.process-list span,
.intro-strip span {
  display: block;
  margin-bottom: 12px;
  color: var(--accent);
  font-weight: 900;
}

.process-list strong,
.intro-strip strong {
  display: block;
  margin-bottom: 8px;
  font-size: 18px;
}

.intro-strip article {
  background: #fff;
}

.faq-list {
  display: grid;
  gap: 12px;
}

.faq-list summary {
  min-height: 52px;
  padding: 16px 18px;
  color: var(--ink);
  font-weight: 900;
  cursor: pointer;
}

.faq-list p {
  padding: 0 18px 18px;
}

.referral-section {
  color: #fff;
  background:
    linear-gradient(135deg, rgba(19, 64, 80, 0.96), rgba(25, 42, 52, 0.98)),
    linear-gradient(90deg, #173f52, #253847);
}

.ambassador-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 28px;
  align-items: center;
}

.ambassador-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}

.ambassador-primary-link {
  padding: 16px 24px;
  font-size: 17px;
  font-weight: 900;
}

.referral-section h2 {
  color: #fff;
}

.ambassador-hero .eyebrow,
.referral-section .eyebrow {
  color: #9fe2ef;
}

.referral-section .section-head p,
.compliance-note {
  color: #dce9ed;
}

.referral-section p {
  color: #dce9ed;
}

.ambassador-page #start {
  background: #f1f6f8;
}

.reward-detail-section {
  background: #f1f6f8;
}

.reward-table {
  overflow: hidden;
  border: 1px solid #d8e2e8;
  border-radius: 8px;
  background: #fff;
}

.reward-row {
  display: grid;
  grid-template-columns: 0.7fr 1.5fr 1fr;
  border-top: 1px solid #d8e2e8;
}

.reward-row:first-child {
  border-top: 0;
}

.reward-row > * {
  min-width: 0;
  padding: 18px;
  border-left: 1px solid #d8e2e8;
  line-height: 1.75;
}

.reward-row > *:first-child {
  border-left: 0;
}

.reward-head {
  background: #173f52;
  color: #fff;
  font-weight: 800;
}

.reward-row strong {
  color: var(--accent-dark);
  font-size: 17px;
}

.reward-row p {
  color: #3a4650;
}

.standalone-note {
  max-width: 1160px;
  margin-top: 0;
  padding: 16px 18px 16px 20px;
  border-left: 5px solid var(--accent);
  border-radius: 0 8px 8px 0;
  background: linear-gradient(90deg, rgba(31, 124, 145, 0.11), rgba(31, 124, 145, 0.035));
  color: #1f2937;
  font-size: 17px;
  font-weight: 900;
  line-height: 1.8;
}

.compliance-note {
  margin-top: 22px;
  padding: 16px 18px;
  border-left: 5px solid #9fe2ef;
  border-radius: 0 8px 8px 0;
  background: rgba(255, 255, 255, 0.08);
  font-weight: 800;
}

.research-modal {
  position: fixed;
  inset: 0;
  z-index: 50;
  display: none;
  align-items: center;
  justify-content: center;
  padding: 28px;
}

.research-modal.active {
  display: flex;
}

.modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(4, 12, 18, 0.76);
  backdrop-filter: blur(8px);
}

.modal-panel {
  position: relative;
  z-index: 1;
  width: min(1080px, 94vw);
  max-height: min(760px, 90vh);
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: 10px;
  background: #fff;
  box-shadow: 0 34px 90px rgba(0, 0, 0, 0.35);
}

.modal-panel img {
  width: 100%;
  height: 100%;
  min-height: 520px;
  object-fit: contain;
  background: #e8eef2;
}

.modal-content {
  overflow: auto;
  padding: 34px;
}

.modal-content h2 {
  margin-bottom: 12px;
}

.modal-content p {
  color: #344054;
  line-height: 1.72;
  margin-bottom: 18px;
}

.modal-content ul {
  display: grid;
  gap: 12px;
  margin: 0;
  padding-left: 18px;
  color: #263442;
  line-height: 1.68;
}

.modal-close {
  position: absolute;
  top: 12px;
  right: 12px;
  z-index: 2;
  width: 38px;
  height: 38px;
  border: 0;
  border-radius: 50%;
  background: rgba(15, 31, 42, 0.85);
  color: #fff;
  font-size: 24px;
  cursor: pointer;
}

body.modal-open {
  overflow: hidden;
}

.footer {
  width: 100%;
  max-width: none;
  display: grid;
  grid-template-columns: minmax(0, 1.3fr) minmax(260px, 0.7fr);
  gap: 20px;
  padding: 34px 24px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  background: #fff;
  align-items: end;
}

.footer p {
  text-align: left;
}

.footer strong {
  display: block;
  margin-bottom: 8px;
  color: var(--ink);
  font-size: 18px;
}

.footer-links {
  justify-content: flex-end;
}

.footer a {
  color: var(--accent-dark);
  font-weight: 800;
}

@media (max-width: 920px) {
  .nav {
    flex-wrap: wrap;
  }

  .nav-toggle {
    display: inline-block;
    margin-left: auto;
  }

  .nav-links {
    display: none;
    width: 100%;
    flex-direction: column;
    gap: 8px;
    padding: 12px;
    border: 1px solid rgba(255, 255, 255, 0.18);
    border-radius: 8px;
    background: rgba(12, 28, 39, 0.94);
  }

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

  .nav-links a {
    min-height: 44px;
    display: flex;
    align-items: center;
  }

  h1 {
    max-width: 10.8em;
    font-size: 32px;
    line-height: 1.16;
    word-break: break-all;
  }

  .lead {
    max-width: 420px;
    font-size: 18px;
    word-break: break-all;
  }

  .research-grid,
  .benefit-grid,
  .resource-layout,
  .program-tabs,
  .program-detail-grid,
  .apply-layout,
  .process-list,
  .intro-strip,
  .referral-grid,
  .ambassador-principles,
  .privilege-grid,
  .reward-row,
  .footer {
    grid-template-columns: 1fr;
  }

  .reward-row > * {
    border-left: 0;
    border-top: 1px solid #d8e2e8;
  }

  .reward-row > *:first-child {
    border-top: 0;
  }

  .reward-head {
    display: none;
  }

  .outcome-grid article {
    grid-template-columns: 1fr;
    gap: 4px;
  }

  .modal-panel {
    grid-template-columns: 1fr;
    width: calc(100vw - 24px);
    max-width: calc(100vw - 24px);
    max-height: 88vh;
  }

  .modal-panel img {
    min-height: 0;
  }

  .footer-links {
    justify-content: flex-start;
  }
}

@media (max-width: 560px) {
  .hero {
    min-height: 600px;
  }

  .hero-inner {
    padding-top: 54px;
  }

  .hero-school {
    font-size: 16px;
  }

  .hero-college,
  .hero-audience {
    font-size: 14px;
  }

  h1 {
    font-size: 30px;
  }

  .page-section {
    padding: 54px 16px;
  }

  .program-tabs button {
    min-height: auto;
  }
}