:root {
  --ink: #0b223f;
  --muted: #536274;
  --navy: #082f63;
  --blue: #0f5da8;
  --green: #1d7a68;
  --gold: #d79a2b;
  --red: #c6412d;
  --paper: #ffffff;
  --wash: #f5f8f6;
  --mist: #edf4f8;
  --line: #d9e1e8;
  --shadow: 0 18px 50px rgba(8, 47, 99, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: Inter, Arial, "Microsoft YaHei", sans-serif;
  line-height: 1.6;
}

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

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: grid;
  grid-template-columns: minmax(220px, 310px) 1fr auto auto;
  align-items: center;
  gap: 22px;
  padding: 14px 30px;
  border-bottom: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(16px);
}

.brand img {
  width: 286px;
}

.nav-toggle {
  display: none;
}

.main-nav {
  display: flex;
  justify-content: center;
  gap: 20px;
  color: var(--muted);
  font-size: 0.94rem;
}

.main-nav a:hover,
.main-nav a.active {
  color: var(--navy);
}

.apply-button,
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  border: 0;
  border-radius: 8px;
  padding: 10px 16px;
  color: #fff;
  background: var(--red);
  font-weight: 800;
  cursor: pointer;
}

.language-switcher {
  display: inline-flex;
  gap: 4px;
  padding: 4px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--wash);
}

.language-switcher button {
  border: 0;
  border-radius: 6px;
  padding: 7px 10px;
  background: transparent;
  color: var(--muted);
  cursor: pointer;
  font: inherit;
  font-size: 0.88rem;
}

.language-switcher button[aria-pressed="true"] {
  color: #fff;
  background: var(--navy);
}

.button.secondary {
  color: var(--navy);
  background: #fff;
  border: 1px solid var(--line);
}

.button.green {
  background: var(--green);
}

.hero {
  position: relative;
  min-height: 690px;
  display: flex;
  align-items: flex-end;
  overflow: hidden;
  background:
    linear-gradient(90deg, rgba(8, 47, 99, 0.92), rgba(8, 47, 99, 0.54), rgba(8, 47, 99, 0.08)),
    url("assets/generated/youth-exchange-hero.jpg") center 48% / cover no-repeat;
}

.hero.compact {
  min-height: 430px;
}

.hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 115px;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0), var(--paper));
}

.hero-inner,
.section,
.footer-inner {
  width: min(1160px, calc(100% - 48px));
  margin: 0 auto;
}

.hero-inner {
  position: relative;
  z-index: 1;
  padding: 120px 0 150px;
  color: #fff;
}

.hero.compact .hero-inner {
  padding: 90px 0 120px;
}

.eyebrow,
.kicker {
  margin: 0 0 12px;
  color: var(--gold);
  font-weight: 800;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

h1,
h2,
h3 {
  margin: 0;
  line-height: 1.12;
}

h1 {
  max-width: 820px;
  font-size: clamp(2.35rem, 5vw, 4.9rem);
}

h2 {
  color: var(--navy);
  font-size: clamp(1.9rem, 3vw, 3rem);
}

h3 {
  color: var(--navy);
  font-size: 1.15rem;
}

.hero-copy {
  max-width: 760px;
  margin: 24px 0 0;
  font-size: 1.16rem;
}

.hero-actions,
.button-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

.trust-strip {
  position: relative;
  z-index: 2;
  width: min(1160px, calc(100% - 48px));
  margin: -70px auto 0;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--line);
  box-shadow: var(--shadow);
}

.trust-strip article {
  min-height: 170px;
  padding: 24px;
  background: #fff;
}

.section {
  padding: 84px 0;
}

.section.narrow {
  max-width: 880px;
}

.section-heading {
  max-width: 840px;
  margin-bottom: 34px;
}

.section p,
.card p,
.program-card p,
.profile-card p,
.form-card p,
.timeline p,
.small-note {
  color: var(--muted);
}

.grid-2,
.grid-3,
.grid-4 {
  display: grid;
  gap: 18px;
}

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

.grid-3 {
  grid-template-columns: repeat(3, 1fr);
}

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

.card,
.program-card,
.profile-card,
.form-card,
.contact-card {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  box-shadow: 0 10px 28px rgba(8, 47, 99, 0.06);
}

.card,
.program-card,
.form-card,
.contact-card {
  padding: 26px;
}

.card strong {
  display: inline-block;
  margin-bottom: 12px;
  color: var(--green);
}

.split {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(320px, 480px);
  gap: 54px;
  align-items: center;
}

.image-card {
  overflow: hidden;
  border-radius: 8px;
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.image-card img {
  width: 100%;
  height: 420px;
  object-fit: cover;
}

.band {
  width: 100%;
  background: var(--mist);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.band .section {
  padding: 72px 0;
}

.program-card {
  display: grid;
  gap: 14px;
}

.tag-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tag {
  display: inline-flex;
  border-radius: 999px;
  padding: 6px 10px;
  color: var(--navy);
  background: var(--mist);
  font-size: 0.84rem;
  font-weight: 700;
}

.tag.green {
  color: #fff;
  background: var(--green);
}

.tag.gold {
  color: #fff;
  background: var(--gold);
}

.photo-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  grid-auto-rows: 260px;
  gap: 14px;
}

.photo-grid figure {
  position: relative;
  margin: 0;
  overflow: hidden;
  border-radius: 8px;
  background: var(--wash);
}

.photo-grid .wide {
  grid-column: span 2;
}

.photo-grid img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.photo-grid figcaption {
  position: absolute;
  left: 12px;
  right: 12px;
  bottom: 12px;
  padding: 8px 10px;
  border-radius: 8px;
  color: #fff;
  background: rgba(8, 47, 99, 0.82);
  font-weight: 800;
}

.profile-card {
  overflow: hidden;
}

.profile-card img {
  width: 100%;
  aspect-ratio: 1 / 1;
  object-fit: cover;
  background: var(--mist);
}

.profile-card div {
  padding: 20px;
}

.timeline {
  display: grid;
  gap: 14px;
}

.timeline article {
  display: grid;
  grid-template-columns: 120px 1fr;
  gap: 18px;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
}

.timeline strong {
  color: var(--green);
}

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

label {
  display: grid;
  gap: 7px;
  color: var(--ink);
  font-weight: 700;
}

input,
select,
textarea {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px 13px;
  color: var(--ink);
  background: #fff;
  font: inherit;
}

textarea {
  min-height: 130px;
  resize: vertical;
}

.full {
  grid-column: 1 / -1;
}

.checkbox {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  color: var(--muted);
  font-weight: 400;
}

.checkbox input {
  width: auto;
  margin-top: 5px;
}

.form-status {
  margin: 16px 0 0;
  padding: 12px 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  color: var(--muted);
  background: #fff;
}

.form-status.success {
  color: #0f5c4d;
  border-color: rgba(15, 92, 77, 0.25);
  background: #eef8f4;
}

.form-status.error {
  color: #9b2f26;
  border-color: rgba(185, 65, 53, 0.25);
  background: #fff1ef;
}

.form-status.loading {
  color: var(--navy);
  border-color: rgba(8, 47, 99, 0.2);
  background: var(--wash);
}

.form-card button[disabled] {
  cursor: wait;
  opacity: 0.68;
}

.qr-box {
  display: grid;
  grid-template-columns: 160px 1fr;
  gap: 20px;
  align-items: center;
}

.qr-box img {
  width: 160px;
  border: 1px solid var(--line);
  border-radius: 8px;
}

.site-footer {
  color: #dbe7f5;
  background: var(--navy);
}

.footer-inner {
  display: grid;
  grid-template-columns: 1.2fr 1fr 1fr;
  gap: 34px;
  padding: 42px 0;
}

.footer-inner h3 {
  color: #fff;
}

.footer-inner a,
.footer-inner p {
  color: #dbe7f5;
}

.footer-links {
  display: grid;
  gap: 8px;
}

.footer-disclaimer {
  grid-column: 1 / -1;
  margin: 0;
  padding-top: 22px;
  border-top: 1px solid rgba(255, 255, 255, 0.18);
  font-size: 0.92rem;
}

.zh {
  display: block;
}

.en + .zh,
p.zh {
  margin-top: 8px;
}

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

body[data-lang="zh"] main.has-zh-page > :not(.zh-page) {
  display: none !important;
}

main.has-zh-page > .zh-page {
  margin-top: 0;
}

body[data-lang="both"] .en,
body[data-lang="both"] .zh,
body:not([data-lang]) .en,
body:not([data-lang]) .zh {
  display: block;
}

@media (max-width: 1080px) {
  .site-header {
    grid-template-columns: 1fr auto;
  }

  .nav-toggle {
    display: inline-flex;
    justify-self: end;
    border: 1px solid var(--line);
    border-radius: 8px;
    padding: 8px 11px;
    background: #fff;
  }

  .main-nav,
  .site-header .apply-button,
  .site-header .language-switcher {
    display: none;
  }

  body.nav-open .main-nav {
    grid-column: 1 / -1;
    display: grid;
    gap: 10px;
    justify-content: stretch;
    padding: 12px 0 6px;
  }

  body.nav-open .site-header .language-switcher {
    grid-column: 1 / -1;
    display: inline-flex;
    width: max-content;
  }

  body.nav-open .main-nav a {
    padding: 10px 0;
    border-top: 1px solid var(--line);
  }

  .grid-4,
  .grid-3,
  .trust-strip,
  .photo-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

@media (max-width: 720px) {
  .site-header {
    padding: 12px 18px;
  }

  .brand img {
    width: 235px;
  }

  .hero,
  .hero.compact {
    min-height: 620px;
    background-position: 54% 50%;
  }

  .hero-inner,
  .section,
  .footer-inner,
  .trust-strip {
    width: calc(100% - 32px);
  }

  .hero-inner,
  .hero.compact .hero-inner {
    padding: 88px 0 132px;
  }

  .grid-2,
  .grid-3,
  .grid-4,
  .trust-strip,
  .photo-grid,
  .footer-inner,
  .form-grid,
  .qr-box {
    grid-template-columns: 1fr;
  }

  .section {
    padding: 58px 0;
  }

  .photo-grid {
    grid-auto-rows: 240px;
  }

  .photo-grid .wide,
  .footer-disclaimer {
    grid-column: auto;
  }

  .timeline article {
    grid-template-columns: 1fr;
  }
}