/* Header, title, main-menu, sub-menu styles */
:root {
  --header-bg: #ffffff;
  --header-border: #e2e8f0;
  --logo-color: #0f172a;
  --logo-shadow: #cbd5e1;
  --nav-text: #0f172a;
  --nav-hover-bg: #e3f2fd;
  --nav-hover-text: #1C2526;
  --dropdown-bg: #ffffff;
  --dropdown-text: #1e293b;
  --dropdown-hover-bg: #f0f4f8;
  --dropdown-sep: rgba(0,0,0,0.08);
  --header-text:  #0f172a ;
  --font-header: 'Inter', sans-serif;
  --font-nav: 'Inter', sans-serif;
  --font-body: 'Inter', sans-serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  color: #1e293b;
  min-height: 100vh;
  background-color: #fcfcfc;
}
body.text-lg { font-size: 1.125rem; }

/* Header: Professional white background */
.site-header {
  background: var(--header-bg);
  color: var(--nav-text);
  padding: 16px 32px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
  box-shadow: 0 1px 3px rgba(0,0,0,0.08);
  border-bottom: 1px solid var(--header-border);
  position: sticky;
  top: 0;
  z-index: 1000;
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  gap: 24px;
}
.logo {
  font-family: var(--font-header);
  font-weight: 600;
  font-size: 1.65rem;
  text-decoration: none;
  color: var(--logo-color);
  letter-spacing: 0.03em;
  white-space: nowrap;
}
.logo-3d {
  color: #0A1F44;
  text-shadow: 1px 1px 2px rgba(13, 71, 161, 0.15);
  transition: opacity 0.2s;
  font-weight: 700;
}
.logo-3d:hover {
  opacity: 0.9;
}

.main-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  align-items: center;
  font-family: var(--font-nav);
  font-weight: 600;
  font-size: 0.95rem;
  letter-spacing: 0.01em;
}
.main-nav > a {
  padding: 12px 18px;
  text-decoration: none;
  color: var(--nav-text);
  transition: all 0.25s ease;
  border-radius: 6px;
  position: relative;
}
.main-nav > a:hover {
  background: var(--nav-hover-bg);
  color: var(--nav-hover-text);
  transform: translateY(-1px);
}
.has-dropdown {
  position: relative;
}
.has-dropdown > a {
  padding: 12px 18px;
  text-decoration: none;
  color: var(--nav-text);
  display: inline-flex;
  align-items: center;
  gap: 6px;
  border-radius: 6px;
  transition: all 0.25s ease;
}
.has-dropdown > a:hover {
  background: var(--nav-hover-bg);
  color: var(--nav-hover-text);
  transform: translateY(-1px);
}
.has-dropdown > a::after {
  content: '';
  display: inline-block;
  width: 0;
  height: 0;
  margin-left: 6px;
  border-left: 5px solid transparent;
  border-right: 5px solid transparent;
  border-top: 5px solid var(--nav-text);
  vertical-align: middle;
  transition: transform 0.2s;
}
.has-dropdown:hover > a::after {
  transform: rotate(180deg);
  border-top-color: var(--nav-hover-text);
}

.dropdown {
  position: absolute;
  top: calc(100% + 8px);
  left: 0;
  min-width: 220px;
  padding: 8px 0;
  z-index: 1000;
  background: var(--dropdown-bg);
  box-shadow: 0 10px 40px rgba(0,0,0,0.12), 0 2px 8px rgba(0,0,0,0.08);
  border-radius: 8px;
  border: 1px solid rgba(0,0,0,0.05);
  display: none;
  animation: fadeInDown 0.2s ease;
  margin-top: 4px;
}
.has-dropdown::after {
  content: '';
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  height: 12px;
  background: transparent;
  z-index: 999;
  pointer-events: auto;
}
@keyframes fadeInDown {
  from { opacity: 0; transform: translateY(-8px); }
  to { opacity: 1; transform: translateY(0); }
}
.has-dropdown:hover .dropdown { display: block; }
.dropdown a {
  display: block;
  padding: 12px 20px;
  white-space: nowrap;
  color: var(--dropdown-text);
  text-decoration: none;
  font-family: var(--font-body);
  font-weight: 400;
  font-size: 0.9rem;
  border-bottom: 1px solid var(--dropdown-sep);
  transition: all 0.2s ease;
  position: relative;
}
.dropdown a:first-child {
  border-top-left-radius: 8px;
  border-top-right-radius: 8px;
}
.dropdown a:last-child {
  border-bottom: none;
  border-bottom-left-radius: 8px;
  border-bottom-right-radius: 8px;
}
.dropdown a:hover {
  background: var(--dropdown-hover-bg);
  color: var(--nav-hover-text);
  padding-left: 24px;
}
.dropdown a::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 3px;
  height: 0;
  background: var(--nav-hover-text);
  transition: height 0.2s ease;
  border-radius: 0 2px 2px 0;
}
.dropdown a:hover::before {
  height: 60%;
}

.menu-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}
.menu-toggle .bar {
  display: block;
  width: 22px;
  height: 2px;
  margin: 5px 0;
  background: var(--header-text);
  border-radius: 1px;
  transition: opacity 0.2s, transform 0.2s;
}
.menu-toggle[aria-expanded="true"] .bar:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.menu-toggle[aria-expanded="true"] .bar:nth-child(2) { opacity: 0; }
.menu-toggle[aria-expanded="true"] .bar:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

@media (min-width: 769px) and (max-width: 1024px) {
  .site-header { padding: 12px 20px; }
  .main-nav > a, .has-dropdown > a { padding: 8px 12px; font-size: 0.95rem; }
}

@media (max-width: 768px) {
  .site-header { padding: 14px 18px; }
  .header-inner { flex-wrap: wrap; }
  .logo { order: 1; font-size: 1.4rem; }
  .menu-toggle { display: block; order: 2; }
  .main-nav {
    display: none;
    width: 100%;
    flex-direction: column;
    order: 3;
    margin-top: 12px;
    padding-top: 12px;
    border-top: 1px solid var(--header-border);
    gap: 0;
  }
  .main-nav.open { display: flex; }
  body.menu-open .logo { display: none; }
  .main-nav > a,
  .has-dropdown > a {
    width: 100%;
    padding: 14px 18px;
    border-bottom: 1px solid var(--header-border);
    border-radius: 0;
    font-size: 0.95rem;
  }
  .has-dropdown { position: static; width: 100%; }
  .has-dropdown > a::after { margin-left: auto; }
  .dropdown {
    position: static;
    min-width: 100%;
    box-shadow: none;
    border-radius: 0;
    padding: 0;
    background: #f8fafc;
    display: block;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
    border: none;
    border-left: 3px solid var(--nav-hover-bg);
    margin-left: 12px;
  }
  .has-dropdown.open .dropdown { max-height: 500px; }
  .dropdown a {
    padding: 12px 18px 12px 32px;
    border-bottom: 1px solid var(--dropdown-sep);
    font-size: 0.9rem;
  }
  .dropdown a::before { display: none; }
}
/* second level dropdown (Trainings menu) */

.has-sub-dropdown {
  position: relative;
}

.has-sub-dropdown > a::after {
  content: "▸";
  float: right;
  font-size: 12px;
}

.sub-dropdown {
  display: none;
  position: absolute;
  left: 100%;
  top: 0;
  background: #ffffff;
  min-width: 200px;
  border-radius: 6px;
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

.has-sub-dropdown:hover .sub-dropdown {
  display: block;
}

.sub-dropdown a {
  display: block;
  padding: 10px 14px;
  color: #334155;
  text-decoration: none;
}

.sub-dropdown a:hover {
  background: #f1f5f9;
}