:root {
  --bg: #e4e9ef;
  --bg-card: #ffffff;
  --accent: #0ea5e9;
  --accent-2: #0284c7;
  --text: #1e293b;
  --muted: #64748b;
  --lead: #475569;
  --border: rgba(100, 116, 139, 0.22);
  --radius: 14px;
  --shadow: 0 10px 36px rgba(15, 23, 42, 0.08);
  --shadow-card-hover: 0 18px 44px rgba(14, 165, 233, 0.14);
  --header-bg: rgba(248, 250, 252, 0.9);
  --footer-bg: #475569;
  --footer-text: #f1f5f9;
  --footer-muted: #cbd5e1;
  --image-scrim: rgba(30, 41, 59, 0.68);
  font-family: "Be Vietnam Pro", system-ui, -apple-system, sans-serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--text);
  background:
    radial-gradient(1000px 520px at 8% -8%, rgba(14, 165, 233, 0.16), transparent),
    radial-gradient(800px 480px at 92% 4%, rgba(186, 230, 253, 0.55), transparent), var(--bg);
  line-height: 1.6;
}

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

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

.wrap {
  width: min(1120px, 92vw);
  margin-inline: auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(12px);
  background: var(--header-bg);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  padding: 0.85rem 0;
  gap: 1rem;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.brand-logo {
  height: 40px;
  width: auto;
  display: block;
}

.site-footer .brand-logo {
  height: 108px;
  width: auto;
  object-fit: contain;
}

.nav {
  display: flex;
  gap: 1.25rem;
  flex-wrap: wrap;
  justify-content: center;
  grid-column: 2;
}

.lang-switch {
  grid-column: 3;
  justify-self: end;
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
}

.lang-btn {
  border: 1px solid var(--border);
  background: #fff;
  border-radius: 999px;
  width: 2rem;
  height: 2rem;
  padding: 0;
  display: grid;
  place-items: center;
  cursor: pointer;
  transition: transform 0.15s, border-color 0.2s, box-shadow 0.2s;
}

.lang-btn img {
  width: 18px;
  height: 12px;
  border-radius: 2px;
}

.lang-btn:hover {
  transform: translateY(-1px);
  border-color: rgba(14, 165, 233, 0.5);
}

.lang-btn.is-active {
  border-color: var(--accent);
  box-shadow: 0 0 0 2px rgba(14, 165, 233, 0.15);
}

.nav a {
  font-size: 0.95rem;
  color: var(--muted);
  transition: color 0.2s;
}

.nav a:hover {
  color: var(--accent-2);
}

.hero {
  padding: 4rem 0 3rem;
}

.hero-grid {
  display: grid;
  gap: 1.25rem 2rem;
  grid-template-columns: 1.12fr 0.88fr;
  grid-template-rows: auto auto;
  align-items: start;
}

.hero-copy {
  grid-column: 1;
  grid-row: 1 / span 2;
  align-self: center;
}

.hero-visual {
  grid-column: 2;
  grid-row: 1;
  position: relative;
  border-radius: calc(var(--radius) + 4px);
  overflow: hidden;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  aspect-ratio: 4 / 3;
  max-height: 320px;
  width: 100%;
}

.hero-visual img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.hero-visual::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, transparent 35%, var(--image-scrim));
  pointer-events: none;
}

.hero-visual-caption {
  position: absolute;
  left: 1rem;
  right: 1rem;
  bottom: 1rem;
  z-index: 1;
  font-size: 0.88rem;
  color: #f1f5f9;
}

@media (max-width: 900px) {
  .header-inner {
    display: flex;
    flex-direction: column;
    align-items: center;
  }

  .lang-switch {
    justify-self: center;
  }

  .hero-grid {
    grid-template-columns: 1fr;
    grid-template-rows: none;
  }

  .hero-copy {
    grid-column: 1;
    grid-row: auto;
  }

  .hero-visual {
    grid-column: 1;
    grid-row: auto;
    max-height: 260px;
  }

  .hero-card {
    grid-column: 1;
    grid-row: auto;
  }
}

.hero h1 {
  font-size: clamp(2rem, 4vw, 2.75rem);
  line-height: 1.15;
  margin: 0 0 1rem;
}

.hero-lead {
  color: var(--muted);
  font-size: 1.05rem;
  max-width: 36rem;
}

.pill-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 1.25rem;
}

.pill {
  border: 1px solid rgba(14, 165, 233, 0.22);
  border-radius: 999px;
  padding: 0.35rem 0.85rem;
  font-size: 0.85rem;
  color: var(--accent-2);
  background: rgba(255, 255, 255, 0.85);
}

.hero-card {
  grid-column: 2;
  grid-row: 2;
  background: linear-gradient(165deg, rgba(14, 165, 233, 0.1) 0%, #ffffff 55%);
  border: 1px solid rgba(14, 165, 233, 0.2);
  border-radius: var(--radius);
  padding: 1.5rem;
  box-shadow: var(--shadow);
}

.hero-card h3 {
  margin: 0 0 0.5rem;
  font-size: 1.1rem;
}

.hero-card p {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
}

.section {
  padding: 3.5rem 0;
}

.section-head {
  margin-bottom: 2rem;
}

.section-head h2 {
  margin: 0 0 0.5rem;
  font-size: clamp(1.5rem, 3vw, 2rem);
}

.section-head p {
  margin: 0;
  color: var(--muted);
  max-width: 42rem;
}

.card-grid {
  display: grid;
  gap: 1.25rem;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
}

a.course-card {
  color: inherit;
}

.course-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  transition: transform 0.2s, border-color 0.2s, box-shadow 0.2s;
}

.course-card:hover {
  transform: translateY(-4px);
  border-color: rgba(14, 165, 233, 0.45);
  box-shadow: var(--shadow-card-hover);
}

.course-card-media {
  position: relative;
  height: 168px;
  flex-shrink: 0;
}

.course-card-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.course-card-body {
  padding: 1.1rem 1.35rem 1.35rem;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
  flex: 1;
}

.course-card-body .stats {
  margin-top: auto;
}

.badge {
  align-self: flex-start;
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 0.25rem 0.55rem;
  border-radius: 6px;
  background: rgba(14, 165, 233, 0.12);
  color: #0369a1;
  border: 1px solid rgba(14, 165, 233, 0.35);
}

.course-card-body h3 {
  margin: 0;
  font-size: 1.15rem;
}

.course-card .subtitle {
  margin: 0;
  color: var(--muted);
  font-size: 0.92rem;
}

.stats {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
  margin-top: auto;
  padding-top: 0.75rem;
  border-top: 1px solid var(--border);
}

.stat {
  font-size: 0.85rem;
  color: var(--muted);
}

.stat strong {
  color: var(--text);
  display: block;
  font-size: 1.05rem;
}

.two-col {
  display: grid;
  gap: 2rem;
  grid-template-columns: 1fr 1fr;
}

@media (max-width: 860px) {
  .two-col {
    grid-template-columns: 1fr;
  }
}

.about-stack {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.about-shot {
  margin: 0;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
}

.about-shot img {
  width: 100%;
  height: auto;
  max-height: 280px;
  object-fit: cover;
  display: block;
}

.prose {
  color: var(--muted);
}

.prose p {
  margin: 0 0 1rem;
}

.prose ul {
  margin: 0;
  padding-left: 1.2rem;
  color: var(--muted);
}

.prose li {
  margin-bottom: 0.5rem;
}

.prose li strong {
  color: var(--text);
}

.news-grid {
  display: grid;
  gap: 1.25rem;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
}

.news-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

a.news-card {
  color: inherit;
  transition: transform 0.2s, border-color 0.2s;
}

a.news-card:hover {
  transform: translateY(-3px);
  border-color: rgba(14, 165, 233, 0.45);
}

.news-thumb {
  height: 200px;
  background: linear-gradient(125deg, rgba(14, 165, 233, 0.35), rgba(186, 230, 253, 0.65));
  position: relative;
}

.news-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.news-body {
  padding: 1.1rem 1.25rem 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  flex: 1;
}

.news-body h3 {
  margin: 0;
  font-size: 1rem;
  line-height: 1.35;
}

.meta {
  font-size: 0.82rem;
  color: var(--muted);
}

.link-more {
  margin-top: auto;
  font-size: 0.9rem;
  color: var(--accent);
  font-weight: 600;
}

.card-cta {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  margin-top: 0.25rem;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--accent);
}

.partner-gallery {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 0.85rem;
  margin-top: 1.5rem;
}

.partner-tile {
  border-radius: 12px;
  overflow: hidden;
  border: 1px solid var(--border);
  aspect-ratio: 4 / 3;
}

.partner-tile img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.35s ease;
}

.partner-tile:hover img {
  transform: scale(1.06);
}

/* —— Trang chi tiết —— */
.page-detail .hero {
  padding-top: 2rem;
}

.btn-back {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.92rem;
  color: var(--accent);
  font-weight: 600;
  margin-bottom: 1.25rem;
}

.btn-back:hover {
  text-decoration: underline;
}

.detail-hero {
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
  margin-bottom: 2rem;
  box-shadow: var(--shadow);
}

.detail-hero img {
  width: 100%;
  max-height: 380px;
  object-fit: cover;
  display: block;
}

.article-body {
  max-width: 42rem;
}

.article-body h2 {
  margin: 2rem 0 0.75rem;
  font-size: 1.25rem;
  color: var(--text);
}

.article-body p {
  margin: 0 0 1rem;
  color: var(--muted);
}

.article-body ul {
  margin: 0 0 1rem;
  padding-left: 1.2rem;
  color: var(--muted);
}

.article-body li {
  margin-bottom: 0.4rem;
}

.article-body strong {
  color: var(--text);
}

.article-body a {
  color: var(--accent);
  text-decoration: underline;
  text-underline-offset: 3px;
}

a.course-card h3,
a.news-card .news-body h3 {
  color: var(--text);
}

.article-lead {
  font-size: 1.08rem;
  color: var(--lead);
  margin: 0 0 1.5rem;
  line-height: 1.65;
}

.detail-title {
  font-size: clamp(1.65rem, 3.5vw, 2.1rem);
  line-height: 1.2;
  margin: 0 0 0.5rem;
}

.detail-meta {
  color: var(--muted);
  font-size: 0.9rem;
  margin-bottom: 1.5rem;
}

.photo-credit {
  font-size: 0.75rem;
  color: var(--muted);
  margin-top: 2rem;
}

.site-footer {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding: 2.5rem 0 2rem;
  background: var(--footer-bg);
  color: var(--footer-text);
}

.footer-grid {
  display: grid;
  gap: 2rem;
  grid-template-columns: 1.2fr 1fr;
}

@media (max-width: 720px) {
  .footer-grid {
    grid-template-columns: 1fr;
  }
}

.site-footer .brand {
  color: var(--footer-text);
  background: #ffffff;
  border-radius: 16px;
  padding: 0.55rem 0.9rem;
  display: inline-flex;
  box-shadow: 0 8px 24px rgba(2, 6, 23, 0.28);
}

.footer-brand p {
  margin: 0.75rem 0 0;
  max-width: 34rem;
  font-size: clamp(1.2rem, 2.2vw, 1.55rem);
  line-height: 1.25;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: #fdba74;
  text-shadow:
    0 1px 0 #fb923c,
    0 2px 0 #f97316,
    0 3px 0 #ea580c,
    0 10px 18px rgba(0, 0, 0, 0.28);
}

.contact-list {
  list-style: none;
  padding: 0;
  margin: 0;
  color: var(--footer-muted);
  font-size: 0.95rem;
}

.contact-list li {
  margin-bottom: 0.65rem;
  display: flex;
  align-items: flex-start;
  gap: 0.55rem;
  line-height: 1.45;
}

.contact-list strong {
  color: var(--footer-text);
}

.contact-icon {
  flex: 0 0 1.1rem;
  display: inline-flex;
  justify-content: center;
  align-items: center;
  margin-top: 0.05rem;
  color: var(--footer-text);
}

.contact-icon-svg {
  width: 1rem;
  height: 1rem;
  display: block;
  fill: currentColor;
}

.contact-list a {
  color: var(--footer-text);
  text-decoration: underline;
  text-underline-offset: 2px;
}

.copy {
  margin-top: 2rem;
  padding-top: 1.25rem;
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  text-align: center;
  color: var(--footer-muted);
  font-size: 0.85rem;
}