/* ===== Base ===== */
html { scroll-behavior: smooth; }
body { font-family: "Be Vietnam Pro", system-ui, sans-serif; color: #1E293B; line-height: 1.6; }
h1, h2, h3, h4, h5, h6 { line-height: 1.2; letter-spacing: -0.02em; }
::selection { background: #2ECC71; color: white; }

/* ===== Site Header ===== */
#site-header.scrolled {
  box-shadow: 0 2px 16px rgba(15, 26, 51, 0.08);
  height: auto;
}
.nav-link { position: relative; transition: color .2s; }
.nav-link:hover { color: #0D9488; }
.nav-link.active { color: #0D9488; }
.nav-link.active::after {
  content: "";
  position: absolute;
  left: 0; right: 0;
  bottom: -26px;
  height: 3px;
  background: #2ECC71;
  border-radius: 2px;
}

/* ===== Buttons ===== */
.btn-primary {
  display: inline-flex; align-items: center; gap: .5rem;
  background: #2ECC71; color: white;
  padding: .75rem 1.5rem;
  border-radius: 9999px;
  font-weight: 600; font-size: 15px;
  transition: all .25s ease;
  box-shadow: 0 4px 14px rgba(46, 204, 113, 0.28);
}
.btn-primary:hover {
  background: #27AE60;
  transform: translateY(-1px) scale(1.02);
  box-shadow: 0 8px 20px rgba(46, 204, 113, 0.38);
}
.btn-outline {
  display: inline-flex; align-items: center; gap: .5rem;
  background: white; color: #1B2A4A;
  padding: .75rem 1.5rem;
  border-radius: 9999px;
  font-weight: 600; font-size: 15px;
  border: 1.5px solid #1B2A4A;
  transition: all .25s ease;
}
.btn-outline:hover {
  background: #1B2A4A; color: white;
  transform: translateY(-1px);
}
.btn-teal {
  display: inline-flex; align-items: center; gap: .5rem;
  background: #0D9488; color: white;
  padding: .6rem 1.25rem;
  border-radius: 9999px;
  font-weight: 600; font-size: 14px;
  transition: all .25s;
}
.btn-teal:hover { background: #0F766E; transform: translateY(-1px); }

.btn-white {
  display: inline-flex; align-items: center; gap: .5rem;
  background: white; color: #1B2A4A;
  padding: .85rem 1.75rem;
  border-radius: 9999px;
  font-weight: 600;
  transition: all .25s;
  box-shadow: 0 4px 14px rgba(0,0,0,0.1);
}
.btn-white:hover { transform: translateY(-2px) scale(1.02); }

/* ===== Social Icons ===== */
.social-icon {
  width: 36px; height: 36px;
  border-radius: 9999px;
  background: rgba(255,255,255,.08);
  display: inline-flex; align-items: center; justify-content: center;
  color: white;
  transition: all .25s;
}
.social-icon:hover { background: #2ECC71; transform: translateY(-2px); }

/* ===== Section Layout ===== */
.section { padding: 96px 24px; }
.section-alt { background: #F8FAFB; }
.container { max-width: 1200px; margin: 0 auto; }

@media (max-width: 768px) {
  .section { padding: 64px 20px; }
}

/* ===== Cards ===== */
.card {
  background: white;
  border-radius: 20px;
  padding: 28px;
  box-shadow: 0 2px 10px rgba(15, 26, 51, 0.04);
  border: 1px solid #F1F5F9;
  transition: all .3s ease;
}
.card:hover {
  transform: translateY(-6px);
  box-shadow: 0 18px 40px rgba(15, 26, 51, 0.1);
  border-color: #E2E8F0;
}

.course-card {
  background: white;
  border-radius: 20px;
  overflow: hidden;
  border: 1px solid #F1F5F9;
  box-shadow: 0 2px 10px rgba(15, 26, 51, 0.04);
  transition: all .3s ease;
  display: flex; flex-direction: column;
}
.course-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 20px 45px rgba(15, 26, 51, 0.12);
}
.course-thumb {
  height: 180px;
  position: relative;
  display: flex; align-items: center; justify-content: center;
  color: white;
  font-size: 56px;
  overflow: hidden;
}
.course-thumb::before {
  content: ""; position: absolute; inset: 0;
  background: radial-gradient(circle at 30% 30%, rgba(255,255,255,.2), transparent 60%);
}
.thumb-1 { background: linear-gradient(135deg, #1B2A4A 0%, #0D9488 100%); }
.thumb-2 { background: linear-gradient(135deg, #0D9488 0%, #2ECC71 100%); }
.thumb-3 { background: linear-gradient(135deg, #F59E0B 0%, #E11D48 100%); }
.thumb-4 { background: linear-gradient(135deg, #8B5CF6 0%, #1B2A4A 100%); }
.thumb-5 { background: linear-gradient(135deg, #2ECC71 0%, #065F46 100%); }
.thumb-6 { background: linear-gradient(135deg, #0EA5E9 0%, #1B2A4A 100%); }

/* ===== Photo thumbnail (real images for blog/news) ===== */
.post-thumb {
  position: relative;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  background: #E2E8F0;
}
.post-thumb img {
  width: 100%; height: 100%;
  object-fit: cover;
  transition: transform .6s ease;
}
.course-card:hover .post-thumb img { transform: scale(1.05); }
.post-thumb::after {
  content: ""; position: absolute; inset: 0;
  background: linear-gradient(to top, rgba(15,26,51,.35) 0%, transparent 60%);
  pointer-events: none;
}
.post-thumb-badge {
  position: absolute; top: 14px; left: 14px;
  z-index: 2;
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  background: rgba(255,255,255,0.92);
}

/* ===== Article (blog detail) typography ===== */
.article-prose { color: #334155; font-size: 17px; line-height: 1.8; }
.article-prose > * + * { margin-top: 1.25rem; }
.article-prose h2 {
  font-size: 28px; font-weight: 700; color: #1B2A4A;
  margin-top: 2.5rem; margin-bottom: .75rem; line-height: 1.25;
  scroll-margin-top: 100px;
}
.article-prose h3 {
  font-size: 22px; font-weight: 700; color: #1B2A4A;
  margin-top: 1.75rem; margin-bottom: .5rem; line-height: 1.3;
}
.article-prose p { font-size: 17px; line-height: 1.8; }
.article-prose .lead {
  font-size: 19px; line-height: 1.7; color: #1E293B;
  font-weight: 500;
  padding: 18px 22px;
  border-left: 4px solid #2ECC71;
  background: #F0FDF4;
  border-radius: 4px 12px 12px 4px;
}
.article-prose ul, .article-prose ol { padding-left: 1.4rem; }
.article-prose ul li { list-style-type: disc; margin: .4rem 0; }
.article-prose ol li { list-style-type: decimal; margin: .4rem 0; }
.article-prose ul li::marker { color: #2ECC71; }
.article-prose ol li::marker { color: #0D9488; font-weight: 700; }
.article-prose blockquote {
  border-left: 4px solid #0D9488;
  background: linear-gradient(135deg, #F0FDFA 0%, #ECFDF5 100%);
  padding: 20px 24px;
  border-radius: 0 12px 12px 0;
  font-style: italic;
  color: #134E4A;
  font-size: 18px;
}
.article-prose blockquote cite {
  display: block; margin-top: 8px;
  font-style: normal; font-weight: 600; color: #0D9488; font-size: 14px;
}
.article-figure {
  margin: 2rem 0;
  border-radius: 16px;
  overflow: hidden;
  box-shadow: 0 8px 24px rgba(15,26,51,.08);
}
.article-figure img { width: 100%; height: auto; display: block; }
.article-figure figcaption {
  padding: 12px 16px;
  background: #F8FAFB;
  font-size: 14px; color: #64748B;
  text-align: center; font-style: italic;
}
.article-callout {
  border-radius: 14px;
  padding: 18px 22px;
  border: 1px solid;
  display: flex; gap: 14px;
  align-items: flex-start;
}
.article-callout .callout-icon {
  width: 36px; height: 36px; border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  font-size: 16px; flex-shrink: 0;
}
.callout-info { background: #EFF6FF; border-color: #BFDBFE; }
.callout-info .callout-icon { background: #3B82F6; color: white; }
.callout-warning { background: #FFFBEB; border-color: #FCD34D; }
.callout-warning .callout-icon { background: #F59E0B; color: white; }
.callout-success { background: #F0FDF4; border-color: #86EFAC; }
.callout-success .callout-icon { background: #2ECC71; color: white; }
.article-table-wrap { overflow-x: auto; border-radius: 14px; border: 1px solid #E2E8F0; }
.article-table { width: 100%; border-collapse: collapse; font-size: 15px; }
.article-table th { background: #1B2A4A; color: white; padding: 12px 16px; text-align: left; font-weight: 600; }
.article-table td { padding: 12px 16px; border-top: 1px solid #E2E8F0; }
.article-table tr:nth-child(even) td { background: #F8FAFB; }
.tag-pill {
  display: inline-block;
  padding: 4px 12px; border-radius: 999px;
  background: #F1F5F9; color: #475569;
  font-size: 12px; font-weight: 500;
  text-decoration: none;
  transition: all .2s ease;
}
.tag-pill:hover { background: #DCFCE7; color: #166534; }

/* ===== Badges ===== */
.badge {
  display: inline-flex; align-items: center; gap: .25rem;
  padding: 4px 12px;
  border-radius: 9999px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .01em;
}
.badge-basic { background: #DBEAFE; color: #1D4ED8; }
.badge-advanced { background: #FFEDD5; color: #C2410C; }
.badge-expert { background: #F3E8FF; color: #7E22CE; }
.badge-new { background: #FEF3C7; color: #B45309; }
.badge-green { background: rgba(46, 204, 113, 0.12); color: #1E874B; }

/* ===== Scroll Animations ===== */
.reveal {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity .8s ease, transform .8s ease;
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}
.reveal-delay-1 { transition-delay: .1s; }
.reveal-delay-2 { transition-delay: .2s; }
.reveal-delay-3 { transition-delay: .3s; }
.reveal-delay-4 { transition-delay: .4s; }

/* ===== Counter/Stats ===== */
.stat-number {
  font-size: 56px;
  font-weight: 800;
  letter-spacing: -0.02em;
  background: linear-gradient(135deg, #2ECC71, #14B8A6);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

/* ===== Hero ===== */
.hero-bg {
  background:
    radial-gradient(ellipse at top right, rgba(46, 204, 113, 0.08), transparent 50%),
    radial-gradient(ellipse at bottom left, rgba(13, 148, 136, 0.06), transparent 50%),
    #FFFFFF;
}
.hero-illust {
  position: relative;
  aspect-ratio: 1;
  max-width: 480px;
  margin: 0 auto;
}
.hero-blob {
  position: absolute;
  border-radius: 50%;
  filter: blur(40px);
  opacity: 0.6;
}

/* ===== Logo strip (marquee) ===== */
.marquee {
  display: flex; gap: 48px;
  animation: marquee 30s linear infinite;
}
@keyframes marquee {
  0% { transform: translateX(0); }
  100% { transform: translateX(-50%); }
}
.logo-placeholder {
  flex-shrink: 0;
  width: 160px; height: 60px;
  background: #F1F5F9;
  border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  color: #64748B;
  font-weight: 600;
  font-size: 14px;
  filter: grayscale(100%);
  opacity: .7;
  transition: all .3s;
}
.logo-placeholder:hover { filter: grayscale(0); opacity: 1; }

/* ===== Roadmap timeline ===== */
.roadmap {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  position: relative;
}
.roadmap::before {
  content: "";
  position: absolute;
  top: 32px; left: 8%; right: 8%;
  height: 3px;
  background: repeating-linear-gradient(to right, #2ECC71 0 10px, transparent 10px 18px);
  z-index: 0;
}
.roadmap-step { text-align: center; position: relative; z-index: 1; }
.roadmap-circle {
  width: 64px; height: 64px;
  border-radius: 50%;
  background: white;
  border: 3px solid #2ECC71;
  display: flex; align-items: center; justify-content: center;
  font-weight: 700;
  font-size: 20px;
  color: #1B2A4A;
  margin: 0 auto 20px;
  box-shadow: 0 4px 14px rgba(46, 204, 113, 0.25);
}
@media (max-width: 768px) {
  .roadmap {
    grid-template-columns: 1fr;
    gap: 32px;
  }
  .roadmap::before { display: none; }
  .roadmap-step { text-align: left; display: grid; grid-template-columns: 80px 1fr; align-items: start; gap: 16px; }
  .roadmap-circle { margin: 0; }
}

/* ===== Testimonial ===== */
.testimonial-star { color: #F59E0B; }

/* ===== Accordion ===== */
.accordion-item {
  border: 1px solid #E2E8F0;
  border-radius: 14px;
  overflow: hidden;
  margin-bottom: 12px;
  background: white;
}
.accordion-header {
  width: 100%;
  text-align: left;
  padding: 20px 24px;
  display: flex; align-items: center; justify-content: space-between;
  gap: 16px;
  cursor: pointer;
  font-weight: 600;
  color: #1B2A4A;
  background: white;
  transition: background .2s;
}
.accordion-header:hover { background: #F8FAFB; }
.accordion-header .chev { transition: transform .3s; color: #0D9488; }
.accordion-item.open .accordion-header .chev { transform: rotate(180deg); }
.accordion-body {
  max-height: 0;
  overflow: hidden;
  transition: max-height .4s ease, padding .4s ease;
  padding: 0 24px;
  color: #475569;
}
.accordion-item.open .accordion-body {
  max-height: 1000px;
  padding: 0 24px 20px;
}

/* ===== Forms ===== */
.form-input {
  width: 100%;
  padding: 14px 18px;
  border: 1.5px solid #E2E8F0;
  border-radius: 12px;
  font-size: 15px;
  color: #1E293B;
  background: white;
  transition: border-color .2s, box-shadow .2s;
  font-family: inherit;
}
.form-input:focus {
  outline: none;
  border-color: #2ECC71;
  box-shadow: 0 0 0 4px rgba(46, 204, 113, 0.12);
}
.form-label {
  display: block;
  font-weight: 600;
  color: #334155;
  margin-bottom: 8px;
  font-size: 14px;
}

/* ===== Instructor avatar ===== */
.avatar-ring {
  width: 120px; height: 120px;
  border-radius: 50%;
  padding: 4px;
  background: linear-gradient(135deg, #2ECC71, #0D9488);
  margin: 0 auto 20px;
}
.avatar-inner {
  width: 100%; height: 100%;
  border-radius: 50%;
  background: linear-gradient(135deg, #1B2A4A, #0D9488);
  color: white;
  display: flex; align-items: center; justify-content: center;
  font-weight: 700;
  font-size: 36px;
}

/* ===== Page hero ===== */
.page-hero {
  background: linear-gradient(135deg, #F8FAFB 0%, #ECFDF5 100%);
  padding: 80px 24px 64px;
  text-align: center;
}

/* ===== Back to top ===== */
#back-to-top.show {
  opacity: 1;
  pointer-events: auto;
}

/* ===== Utilities ===== */
.gradient-text {
  background: linear-gradient(135deg, #2ECC71 0%, #0D9488 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.check-item { display: flex; align-items: flex-start; gap: 12px; }
.check-item .check-icon {
  width: 24px; height: 24px; border-radius: 50%;
  background: rgba(46, 204, 113, 0.15);
  color: #1E874B;
  display: flex; align-items: center; justify-content: center;
  font-size: 12px;
  flex-shrink: 0;
  margin-top: 2px;
}

/* mobile drawer state */
#mobile-drawer.open { opacity: 1; pointer-events: auto; }
#mobile-drawer.open #mobile-drawer-panel { transform: translateX(0); }