/* Alibaba Study Tour 2026 — Newing
   Brand tokens read from newing.vn (navy #122757 / #071B3E, signature gold sunburst
   #FFD46C→#FFE7AE→#FFF6E4) and the dark-mode pair already validated for AA contrast
   on other Newing surfaces (loki-newing-ops-sandbox / newing-ops-demo theme.json). */

@import url('https://fonts.googleapis.com/css2?family=Be+Vietnam+Pro:ital,wght@0,400;0,500;0,600;0,700;0,800;0,900;1,400;1,500;1,600&display=swap');

:root {
  --bg: #FCFCFB;
  --bg-raised: #F6F4EE;
  --ink: #0E1B33;
  --ink-muted: #4C5476;
  --navy: #122757;
  --navy-deep: #071B3E;
  --border: #DEE2EA;
  --border-soft: #E9E6DC;
  --gold-chip: #FFDF92;
  --gold-line: #D9A834;
  --gold-1: #FFD46C;
  --gold-2: #FFE7AE;
  --gold-3: #FFF6E4;
  --rail-w: 9rem;

  --font: 'Be Vietnam Pro', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #071B3E;
    --bg-raised: #0F2447;
    --ink: #EEF1F6;
    --ink-muted: #9AA8C2;
    --navy: #3F6FAE;
    --navy-deep: #EEF1F6;
    --border: #2A4D7C;
    --border-soft: #1C3A66;
    --gold-line: #FFDF92;
    color-scheme: dark;
  }
}

html[lang="vi"] [data-i18n-en] { display: none; }
html[lang="en"] [data-i18n-vi] { display: none; }

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; }
}

body {
  margin: 0;
  font-family: var(--font);
  background: var(--bg);
  color: var(--ink);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

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

:focus-visible {
  outline: 2px solid var(--gold-line);
  outline-offset: 3px;
}

.container {
  max-width: 1120px;
  margin-inline: auto;
  padding-inline: 1.5rem;
}

@media (min-width: 640px) {
  .container { padding-inline: 2.5rem; }
}

/* ---------- Header ---------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border-soft);
}

.site-header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding-block: 0.9rem;
}

.brand { display: inline-flex; align-items: center; }
.brand-logo { height: 20px; width: auto; }

@media (prefers-color-scheme: dark) {
  .brand-logo { filter: brightness(0) invert(1); }
}

.site-header-right {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.site-tag {
  margin: 0;
  font-size: 0.875rem;
  font-weight: 600;
  letter-spacing: 0.01em;
  color: var(--ink-muted);
  text-align: right;
}

@media (max-width: 479px) {
  .site-tag { display: none; }
}

.lang-switch {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  flex-shrink: 0;
}

.lang-btn {
  appearance: none;
  border: none;
  background: transparent;
  font-family: inherit;
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--ink-muted);
  padding: 0.3rem 0.45rem;
  border-radius: 0.4rem;
  cursor: pointer;
}

.lang-btn:hover { color: var(--navy-deep); }

@media (prefers-color-scheme: dark) {
  .lang-btn:hover { color: var(--ink); }
}

.lang-btn[aria-pressed="true"] {
  color: var(--navy-deep);
  background: var(--gold-chip);
}

@media (prefers-color-scheme: dark) {
  .lang-btn[aria-pressed="true"] { color: #071B3E; }
}

.lang-sep { color: var(--border); font-size: 0.8rem; }

/* ---------- In-page section nav ---------- */

.section-nav { border-top: 1px solid var(--border-soft); }

.section-nav-inner {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem 1.25rem;
  padding-block: 0.55rem;
}

.section-nav a {
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.01em;
  color: var(--ink-muted);
  text-decoration: none;
  padding: 0.15rem 0.1rem;
  border-radius: 0.3rem;
}

.section-nav a:hover { color: var(--navy-deep); }

@media (prefers-color-scheme: dark) {
  .section-nav a:hover { color: var(--ink); }
}

/* ---------- Hero ---------- */

.hero {
  position: relative;
  overflow: hidden;
  padding-block: 4rem 3.5rem;
  background:
    radial-gradient(760px 460px at 90% -12%, var(--gold-2) 0%, transparent 62%),
    radial-gradient(420px 360px at 104% 14%, var(--gold-1) 0%, transparent 58%),
    var(--bg);
}

@media (prefers-color-scheme: dark) {
  .hero {
    background:
      radial-gradient(760px 460px at 90% -12%, rgba(255, 223, 146, 0.14) 0%, transparent 62%),
      radial-gradient(420px 360px at 104% 14%, rgba(255, 212, 108, 0.1) 0%, transparent 58%),
      var(--bg);
  }
}

@media (min-width: 768px) {
  .hero { padding-block: 6rem 4.5rem; }
}

.hero-inner {
  max-width: 44rem;
  animation: hero-rise 0.6s ease-out both;
}

@keyframes hero-rise {
  from { opacity: 0; transform: translateY(14px); }
  to { opacity: 1; transform: translateY(0); }
}

@media (prefers-reduced-motion: reduce) {
  .hero-inner { animation: none; }
}

.hero h1 {
  margin: 0 0 0.9rem;
  font-size: clamp(2.25rem, 1.55rem + 3vw, 3.5rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.06;
  color: var(--navy-deep);
}

.hero-meta {
  margin: 0 0 1.5rem;
  font-size: clamp(1rem, 0.94rem + 0.3vw, 1.125rem);
  font-weight: 600;
  color: var(--navy);
}

@media (prefers-color-scheme: dark) {
  .hero-meta { color: var(--gold-line); }
}

.hero-meta .dot { color: var(--gold-line); margin-inline: 0.15em; font-weight: 700; }

.hero-intro {
  margin: 0;
  max-width: 58ch;
  font-size: 1.125rem;
  line-height: 1.65;
  color: var(--ink-muted);
}

/* ---------- Agenda section ---------- */

.agenda { padding-block: 1rem 5rem; }

.agenda h2 {
  margin: 0 0 1.25rem;
  font-size: clamp(1.625rem, 1.45rem + 0.9vw, 2.125rem);
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--navy-deep);
}

.agenda-tz-note {
  margin: 0 0 2.5rem;
  padding: 0.85rem 1.1rem;
  border: 1px solid var(--border-soft);
  border-left: 3px solid var(--gold-line);
  border-radius: 0.6rem;
  background: var(--bg-raised);
  font-size: 0.95rem;
  font-weight: 600;
  line-height: 1.5;
  color: var(--ink);
}

.itinerary {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
}

.itinerary::before {
  content: "";
  position: absolute;
  left: calc(var(--rail-w) + 1rem);
  top: 0.75rem;
  bottom: 0.75rem;
  width: 2px;
  background: var(--border);
}

.day {
  position: relative;
  display: grid;
  grid-template-columns: var(--rail-w) 1fr;
  gap: 2rem;
  padding-block: 2.25rem;
}

.day:first-child { padding-top: 0.25rem; }

.day + .day { border-top: 1px solid var(--border-soft); }

.day::after {
  content: "";
  position: absolute;
  left: calc(var(--rail-w) + 1rem - 5px);
  top: 0.45rem;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--border);
  border: 2px solid var(--bg);
}

.day--full::after {
  width: 14px;
  height: 14px;
  left: calc(var(--rail-w) + 1rem - 7px);
  background: var(--gold-line);
  border-color: var(--bg);
}

.day-date {
  margin: 0;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--ink-muted);
}

.day-date .day-date-sep { color: var(--border); margin-inline: 0.1em; }

.day--full .day-date {
  display: inline-block;
  padding: 0.3rem 0.7rem;
  border-radius: 999px;
  background: var(--gold-chip);
  color: var(--navy-deep);
  font-weight: 700;
}

@media (prefers-color-scheme: dark) {
  .day--full .day-date { color: #071B3E; }
}

.day--full .day-date .day-date-sep { color: var(--navy-deep); opacity: 0.5; }

.day-note {
  margin: 0 0 1.75rem;
  font-style: italic;
  color: var(--ink-muted);
}

.day-heading { margin-bottom: 1.75rem; }

.day-heading h3 {
  margin: 0 0 0.35rem;
  font-size: clamp(1.375rem, 1.25rem + 0.6vw, 1.75rem);
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--navy-deep);
}

.day-time {
  margin: 0;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--ink-muted);
}

.period + .period { margin-top: 1.75rem; }

.period-label {
  margin: 0 0 0.9rem;
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-muted);
}

.session {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  padding-left: 1rem;
  border-left: 2px solid var(--border);
}

.session + .session { margin-top: 1.1rem; }

.session-time {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  column-gap: 0.4rem;
  row-gap: 0.1rem;
  font-size: 0.875rem;
}

.time-hz {
  font-weight: 700;
  color: var(--navy-deep);
}

@media (prefers-color-scheme: dark) {
  .time-hz { color: var(--ink); }
}

.session-body p {
  margin: 0;
  font-size: 1.0625rem;
  line-height: 1.55;
}

.session-body p + p { margin-top: 0.35rem; }

.session-speaker,
.session-pending {
  font-size: 0.95rem !important;
  color: var(--ink-muted);
}

.session-pending { font-style: italic; }

.topic-label {
  margin: 0 0 0.25rem !important;
  font-size: 0.8rem !important;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--ink-muted) !important;
}

.topic-en-original {
  font-style: italic;
  font-weight: 500;
  font-size: 0.95rem !important;
  color: var(--ink-muted) !important;
}

.topic-vi-translation { font-size: 1.0625rem !important; }

.transfer-note {
  margin: 0 0 1.1rem;
  padding-left: 1rem;
  border-left: 2px dashed var(--border);
  font-size: 0.9rem;
  font-style: italic;
  color: var(--ink-muted);
}

/* ---------- Mobile itinerary collapse ---------- */

@media (max-width: 639px) {
  .itinerary::before { display: none; }
  .day { grid-template-columns: 1fr; gap: 0.9rem; }
  .day::after { display: none; }
  .day-content {
    border-left: 3px solid var(--border);
    padding-left: 1.1rem;
  }
  .day--full .day-content { border-left-color: var(--gold-line); }
  .day-date { display: inline-block; }
}

/* ---------- Speakers ---------- */

.speakers { padding-block: 1rem 5rem; }

.speakers h2 {
  margin: 0 0 2rem;
  font-size: clamp(1.625rem, 1.45rem + 0.9vw, 2.125rem);
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--navy-deep);
}

.speaker-grid {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(16rem, 1fr));
  gap: 1.5rem;
}

.speaker-card {
  padding: 1.5rem;
  border: 1px solid var(--border-soft);
  border-radius: 0.9rem;
  background: var(--bg-raised);
}

.speaker-name {
  margin: 0 0 0.3rem;
  font-size: 1.1875rem;
  font-weight: 800;
  color: var(--navy-deep);
}

.speaker-role {
  margin: 0 0 0.75rem;
  font-size: 0.9375rem;
  font-weight: 700;
  color: var(--navy-deep);
}

.speaker-bio {
  margin: 0;
  font-size: 1rem;
  line-height: 1.6;
  color: var(--ink-muted);
}

/* ---------- Interpretation ---------- */

.interpretation { padding-block: 1rem 5rem; }

.interpretation h2 {
  margin: 0 0 1.25rem;
  font-size: clamp(1.625rem, 1.45rem + 0.9vw, 2.125rem);
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--navy-deep);
}

.interpretation-intro {
  margin: 0 0 1.75rem;
  max-width: 62ch;
  font-size: 1.0625rem;
  line-height: 1.6;
  color: var(--ink-muted);
}

.interpretation-points {
  list-style: none;
  margin: 0;
  padding: 0;
  max-width: 62ch;
  display: flex;
  flex-direction: column;
  gap: 1.1rem;
}

.interpretation-points > li {
  position: relative;
  padding-left: 1.4rem;
  font-size: 1.0625rem;
  line-height: 1.55;
  color: var(--ink);
}

.interpretation-points > li::before {
  content: "";
  position: absolute;
  left: 0.1rem;
  top: 0.6em;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--gold-line);
}

.interpretation-subpoints {
  list-style: none;
  margin: 0.6rem 0 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.interpretation-subpoints li {
  position: relative;
  padding-left: 1.2rem;
  font-size: 1rem;
  line-height: 1.5;
  color: var(--ink-muted);
}

.interpretation-subpoints li::before {
  content: "";
  position: absolute;
  left: 0.1rem;
  top: 0.55em;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--border);
}

/* ---------- Footer ---------- */

.site-footer {
  border-top: 1px solid var(--border-soft);
  padding-block: 2rem;
}

.site-footer-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
}

.footer-brand {
  margin: 0;
  font-weight: 600;
  color: var(--navy-deep);
}

.footer-brand .dot { color: var(--gold-line); margin-inline: 0.2em; }

.footer-brand a { text-decoration: none; }
.footer-brand a:hover { text-decoration: underline; }

.footer-credit {
  margin: 0;
  font-size: 0.85rem;
  color: var(--ink-muted);
}

.footer-credit a { text-decoration: none; }
.footer-credit a:hover { text-decoration: underline; }