:root{
  --bg:#0f172a;
  --bg-soft:#111c34;
  --card:#ffffff;
  --text:#1f2937;
  --muted:#6b7280;
  --primary:#2563eb;
  --primary-dark:#1d4ed8;
  --accent:#38bdf8;
  --line:#e5e7eb;
  --white:#ffffff;
  --shadow:0 10px 30px rgba(0,0,0,0.08);
  --radius:18px;
}

*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{
  font-family:"Segoe UI",Arial,sans-serif;
  background:linear-gradient(135deg,#eef4fb,#f8fbff 40%,#e0ecff);
  color:var(--text);
  line-height:1.7;
}
a{color:var(--primary);text-decoration:none}
a:hover{text-decoration:underline}
.container{max-width:1150px;margin:0 auto;padding:0 20px}

/* Header */
.site-header{
  background:rgba(15,23,42,.95);
  backdrop-filter:blur(10px);
  position:sticky;top:0;z-index:1000;
  border-bottom:1px solid rgba(255,255,255,.08);
}
.nav-wrap{
  display:flex;align-items:center;justify-content:space-between;
  padding:16px 0;gap:20px;flex-wrap:wrap;
}
.logo{color:#fff;font-size:1.2rem;font-weight:700;text-decoration:none}
.nav-links{list-style:none;display:flex;gap:18px;flex-wrap:wrap}
.nav-links a{color:#dbeafe;font-weight:600;transition:.2s;text-decoration:none}
.nav-links a:hover,.nav-links a.active{color:#fff}
.lang-switch{display:flex;gap:8px}
.lang-switch button{
  border:none;background:#1e293b;color:#fff;padding:8px 10px;
  border-radius:10px;cursor:pointer;font-weight:600;
}
.lang-switch button:hover{background:#334155}

/* Shared */
.page-pad{padding:40px 0 60px}
.page-title{margin-bottom:26px}
.page-title h1{font-size:2.2rem;line-height:1.2;color:#0f172a;margin-bottom:10px}
.page-title p{color:var(--muted);max-width:760px}

.card{
  background:#fff;border:1px solid var(--line);border-radius:var(--radius);
  padding:26px;box-shadow:var(--shadow);margin-bottom:22px;
}
.card h2{font-size:1.4rem;line-height:1.3;color:#0f172a;margin-bottom:14px}
.card h3{font-size:1.05rem;color:#0f172a;margin-bottom:10px}
.clean-list{padding-left:20px}
.clean-list li{margin-bottom:10px}
.grid-2{display:grid;grid-template-columns:1fr 1fr;gap:16px}
.grid-3{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.mini-card{
  background:#f8fbff;border:1px solid #e5edf7;border-radius:14px;
  padding:16px;color:#334155;box-shadow:0 6px 18px rgba(15,23,42,.04);
}

/* Hero */
.hero{
  background:radial-gradient(circle at top left,#1d4ed8,#0f172a 70%);
  color:#fff;padding:84px 0 76px;
}
.hero-grid{display:grid;grid-template-columns:1.5fr 1fr;gap:30px;align-items:center}
.eyebrow{
  text-transform:uppercase;letter-spacing:1px;color:#93c5fd;
  margin-bottom:14px;font-size:.92rem;font-weight:700;
}
.hero h1{font-size:3rem;line-height:1.15;margin-bottom:18px}
.hero-text{font-size:1.08rem;color:#dbeafe;max-width:700px}
.hero-buttons{margin-top:24px;display:flex;gap:14px;flex-wrap:wrap}
.btn{
  display:inline-block;padding:12px 20px;border-radius:12px;text-decoration:none;
  font-weight:700;transition:.25s;border:none;cursor:pointer;
}
.btn.primary{background:var(--accent);color:#082f49}
.btn.primary:hover{transform:translateY(-2px);background:#7dd3fc}
.btn.secondary{background:transparent;color:#fff;border:1px solid rgba(255,255,255,.25)}
.btn.secondary:hover{background:rgba(255,255,255,.08)}
.hero-card{
  background:rgba(255,255,255,.08);
  border:1px solid rgba(255,255,255,.12);
  padding:24px;border-radius:20px;box-shadow:var(--shadow);
}
.hero-card h3{margin-bottom:12px;color:#fff}
.hero-card ul{padding-left:20px;color:#dbeafe}

/* Section helpers */
.section-kicker{
  font-size:.78rem;font-weight:800;letter-spacing:1.5px;text-transform:uppercase;
  color:#1d4ed8;margin-bottom:8px;
}
.stats-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:16px}
.stat-card{
  background:#fff;border:1px solid #e6edf7;border-radius:18px;padding:20px;
  box-shadow:0 10px 24px rgba(15,23,42,.05);text-align:center;
}
.stat-card strong{display:block;font-size:1.7rem;color:#0f172a}
.stat-card span{color:#64748b;font-size:.95rem}

/* Feature cards */
.feature-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.feature-card{
  background:#fff;border:1px solid #e6edf7;border-radius:20px;padding:22px;
  box-shadow:0 10px 24px rgba(15,23,42,.05);
  transition:transform .2s ease, box-shadow .2s ease;
}
.feature-card:hover{
  transform:translateY(-4px);
  box-shadow:0 18px 34px rgba(15,23,42,.08);
}
.feature-card h3{margin-bottom:10px;color:#0f172a}
.feature-card p{color:#64748b}

/* Lectures modern */
.lectures-modern{padding-top:24px;padding-bottom:40px}
.lectures-hero-card{
  display:grid;grid-template-columns:1.6fr .9fr;gap:24px;padding:32px;margin-bottom:26px;
  background:linear-gradient(135deg,#ffffff 0%,#f8fbff 100%);
  border:1px solid #e6edf7;border-radius:24px;
  box-shadow:0 12px 30px rgba(15,23,42,.06);
}
.lectures-kicker{
  font-size:.78rem;font-weight:800;letter-spacing:1.6px;text-transform:uppercase;
  color:#2563eb;margin-bottom:10px;
}
.lectures-hero-copy h1{font-size:2.4rem;line-height:1.12;color:#0f172a;margin-bottom:14px}
.lectures-intro{color:#64748b;max-width:760px;font-size:1rem}
.lectures-hero-badge{display:flex;align-items:stretch}
.lectures-badge-box{
  width:100%;background:linear-gradient(135deg,#0f172a 0%,#1e3a8a 100%);
  color:#fff;border-radius:20px;padding:22px;display:flex;flex-direction:column;
  justify-content:center;box-shadow:0 10px 24px rgba(30,58,138,.18);
}
.lectures-badge-label{
  font-size:.78rem;text-transform:uppercase;letter-spacing:1.4px;color:#93c5fd;
  margin-bottom:10px;font-weight:700;
}
.lectures-card-grid{display:grid;grid-template-columns:1fr 1fr;gap:22px}
.lecture-card{
  background:#fff;border:1px solid #e6edf7;border-radius:22px;padding:24px;
  box-shadow:0 10px 24px rgba(15,23,42,.05);
}
.lecture-card-wide{grid-column:1 / -1}
.lecture-card-head{margin-bottom:16px}
.lecture-label{
  font-size:.76rem;font-weight:800;letter-spacing:1.5px;text-transform:uppercase;
  color:#2563eb;margin-bottom:8px;
}
.lecture-card h2{font-size:1.35rem;line-height:1.25;color:#0f172a}
.lecture-card p{color:#475569}
.lecture-pill-wrap{display:flex;flex-wrap:wrap;gap:10px}
.lecture-pill{
  display:inline-flex;align-items:center;padding:10px 14px;border-radius:999px;
  background:#eff6ff;color:#1d4ed8;font-size:.92rem;font-weight:700;border:1px solid #dbeafe;
}
.course-card-grid{display:grid;grid-template-columns:1fr 1fr;gap:18px}
.course-brand-card{
  border:1px solid #e8eef7;background:#fbfdff;border-radius:18px;padding:20px;
}
.course-brand-card h3{color:#0f172a;margin-bottom:12px;font-size:1.05rem;line-height:1.35}
.course-list-modern,.feature-list-modern{padding-left:18px;color:#475569}
.course-list-modern li,.feature-list-modern li{margin-bottom:8px}
.assessment-modern{display:flex;flex-wrap:wrap;gap:10px}
.assessment-chip{
  display:inline-flex;align-items:center;padding:10px 14px;border-radius:999px;
  background:#f8fafc;border:1px solid #e2e8f0;color:#334155;font-size:.92rem;font-weight:600;
}

/* Publications */
.pub-item{
  padding:18px 0;border-bottom:1px solid #e8eef7;
}
.pub-item:last-child{border-bottom:none}
.pub-meta{
  display:flex;gap:10px;flex-wrap:wrap;margin-top:8px;
}
.pub-tag{
  display:inline-block;padding:6px 10px;border-radius:999px;
  background:#eff6ff;color:#1d4ed8;font-size:.82rem;font-weight:700;
}

/* Contact */
.contact-wrap{display:grid;grid-template-columns:1fr 1fr;gap:22px}
.contact-message-card{
  border:1px solid #e5edf7;border-radius:20px;padding:28px;
  background:linear-gradient(180deg,#ffffff 0%,#fbfdff 100%);
  box-shadow:0 10px 30px rgba(15,23,42,.06);
}
.contact-message-header{margin-bottom:22px}
.contact-message-kicker{
  font-size:.78rem;font-weight:800;letter-spacing:1.5px;text-transform:uppercase;
  color:#1d4ed8;margin-bottom:8px;
}
.contact-message-card h2{
  margin-bottom:10px;color:#0f172a;font-size:1.6rem;line-height:1.25;
}
.contact-message-intro{color:#64748b;max-width:700px;font-size:.98rem}
.contact-message-form{margin-top:8px}
.contact-message-grid{display:grid;grid-template-columns:1fr 1fr;gap:18px}
.contact-field{display:flex;flex-direction:column;margin-bottom:18px}
.contact-field label{font-size:.92rem;font-weight:700;color:#1e293b;margin-bottom:8px}
.contact-field input,.contact-field textarea{
  width:100%;border:1px solid #dbe4f0;background:#fff;border-radius:14px;
  padding:14px 16px;font-size:.98rem;color:#1f2937;outline:none;
  transition:border-color .2s ease, box-shadow .2s ease;
}
.contact-field input::placeholder,.contact-field textarea::placeholder{color:#94a3b8}
.contact-field input:focus,.contact-field textarea:focus{
  border-color:#2563eb;box-shadow:0 0 0 4px rgba(37,99,235,.10);
}
.contact-field textarea{resize:vertical;min-height:160px}
.contact-message-actions{display:flex;justify-content:flex-start;margin-top:4px}
.contact-submit-btn{
  border:none;background:linear-gradient(135deg,#1d4ed8,#2563eb);color:#fff;
  padding:13px 22px;border-radius:12px;font-weight:700;font-size:.96rem;cursor:pointer;
  box-shadow:0 8px 18px rgba(37,99,235,.20);
}
.contact-info-card .mini-card{margin-bottom:14px}

/* Footer */
.site-footer{
  background:#0f172a;color:#cbd5e1;padding:24px 0;text-align:center;margin-top:40px;
}

/* Reveal */
.reveal{opacity:0;transform:translateY(16px);transition:all .55s ease}
.reveal.show{opacity:1;transform:none}

/* Responsive */
@media (max-width:960px){
  .hero-grid,.grid-2,.grid-3,.feature-grid,.stats-grid,
  .lectures-hero-card,.lectures-card-grid,.course-card-grid,.contact-wrap{
    grid-template-columns:1fr;
  }
  .lecture-card-wide{grid-column:auto}
  .hero h1{font-size:2.4rem}
}
@media (max-width:768px){
  .contact-message-grid{grid-template-columns:1fr}
  .contact-message-card{padding:22px}
  .contact-message-card h2{font-size:1.35rem}
}
@media (max-width:640px){
  .lectures-hero-card,.lecture-card,.card{padding:20px}
  .lectures-hero-copy h1,.page-title h1{font-size:1.9rem}
  .nav-wrap{align-items:flex-start}
}

.course-brand-card{
  transition:transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}

.course-brand-card:hover{
  transform:translateY(-4px);
  border-color:#cfe0fb;
  box-shadow:0 16px 30px rgba(15,23,42,0.08);
}

.course-filter-panel{
  background:#fff;
  border:1px solid #e6edf7;
  border-radius:22px;
  padding:24px;
  margin-bottom:22px;
  box-shadow:0 10px 24px rgba(15,23,42,.05);
}

.course-filter-header h2{
  font-size:1.35rem;
  color:#0f172a;
}

.course-filter-buttons{
  display:flex;
  flex-wrap:wrap;
  gap:10px;
  margin-top:16px;
}

.filter-btn{
  border:1px solid #dbeafe;
  background:#eff6ff;
  color:#1d4ed8;
  padding:10px 14px;
  border-radius:999px;
  font-size:.92rem;
  font-weight:700;
  cursor:pointer;
  transition:.2s ease;
}

.filter-btn:hover{
  transform:translateY(-2px);
  background:#dbeafe;
}

.filter-btn.active{
  background:linear-gradient(135deg,#1d4ed8,#2563eb);
  color:#fff;
  border-color:#2563eb;
  box-shadow:0 8px 18px rgba(37,99,235,.18);
}

.course-catalog-grid{
  display:grid;
  grid-template-columns:1fr 1fr;
  gap:18px;
}

.course-detail-card{
  background:#fff;
  border:1px solid #e6edf7;
  border-radius:20px;
  box-shadow:0 10px 24px rgba(15,23,42,.05);
  overflow:hidden;
}

.course-accordion{
  width:100%;
  border:none;
  background:linear-gradient(180deg,#ffffff 0%,#fbfdff 100%);
  padding:18px 20px;
  text-align:left;
  display:flex;
  justify-content:space-between;
  align-items:center;
  gap:18px;
  cursor:pointer;
  font-size:1rem;
  font-weight:700;
  color:#0f172a;
}

.course-accordion-icon{
  width:28px;
  height:28px;
  border-radius:50%;
  display:inline-flex;
  align-items:center;
  justify-content:center;
  background:#eff6ff;
  color:#1d4ed8;
  font-size:1.1rem;
  font-weight:800;
  flex-shrink:0;
}

.course-accordion-body{
  max-height:0;
  overflow:hidden;
  transition:max-height .3s ease, padding .3s ease;
  padding:0 20px;
}

.course-detail-card.open .course-accordion-body{
  max-height:500px;
  padding:0 20px 20px;
}

.course-detail-card.open .course-accordion-icon{
  background:#dbeafe;
}

.course-meta-row{
  display:flex;
  flex-wrap:wrap;
  gap:8px;
  margin:2px 0 12px;
}

.course-tag{
  display:inline-flex;
  align-items:center;
  padding:6px 10px;
  border-radius:999px;
  background:#f8fafc;
  border:1px solid #e2e8f0;
  color:#334155;
  font-size:.82rem;
  font-weight:700;
}

.course-accordion-body p{
  color:#475569;
  margin-bottom:12px;
}

@media (max-width:960px){
  .course-catalog-grid{
    grid-template-columns:1fr;
  }
}