/* =====================================================
   ARTIFEX Header — always-white fixed header (order 3)
   Markup contract: header#header_containner > nav >
   a.site-logo + ul#nav_ul > li.mainMenu > a + ul.subMenu
   + button#navBtn (hamburger) + a.header-cta
   ===================================================== */

#header_containner {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-h);
  background: rgba(255, 255, 255, .88);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  z-index: var(--z-header);
  transition: border-color var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}
#header_containner.is-scrolled {
  border-bottom-color: var(--line-200);
  box-shadow: var(--shadow-sm);
}

#header_containner > nav {
  max-width: var(--container);
  height: 100%;
  margin-inline: auto;
  padding-inline: var(--container-pad);
  display: flex;
  align-items: center;
  gap: var(--sp-8);
}

.site-logo { display: inline-flex; align-items: center; flex: none; }
.site-logo img { height: 28px; width: auto; }

/* ---- Primary nav ---- */
#nav_ul {
  display: flex;
  align-items: center;
  gap: 40px;
  margin-left: auto;
  height: 100%;
}

#nav_ul > li.mainMenu {
  position: relative;
  height: 100%;
  display: flex;
  align-items: center;
}

#nav_ul > li.mainMenu > a {
  position: relative;
  display: flex;
  align-items: center;
  height: 100%;
  font-size: 15px;
  font-weight: 500;
  color: var(--ink-700);
  transition: color var(--dur) var(--ease);
}
#nav_ul > li.mainMenu > a::after {
  content: "";
  position: absolute;
  left: 0; right: 0; bottom: 18px;
  height: 2px;
  background: var(--brand-600);
  opacity: 0;
  transition: opacity var(--dur) var(--ease);
}
#nav_ul > li.mainMenu:hover > a,
#nav_ul > li.mainMenu > a.is-active { color: var(--ink-900); }
#nav_ul > li.mainMenu:hover > a::after,
#nav_ul > li.mainMenu > a.is-active::after { opacity: 1; }

/* ---- Dropdown ---- */
#nav_ul .subMenu {
  position: absolute;
  top: calc(100% - 8px);
  left: 50%;
  transform: translate(-50%, 8px);
  min-width: 180px;
  background: var(--bg-0);
  border: 1px solid var(--line-200);
  border-radius: var(--r-md);
  box-shadow: var(--shadow-sm);
  padding: var(--sp-2);
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--dur) var(--ease), transform var(--dur) var(--ease),
              visibility var(--dur) var(--ease);
  z-index: var(--z-dropdown);
}
#nav_ul > li.mainMenu:hover .subMenu,
#nav_ul > li.mainMenu:focus-within .subMenu {
  opacity: 1;
  visibility: visible;
  transform: translate(-50%, 0);
}
#nav_ul .subMenu li a {
  display: block;
  font-size: var(--text-sm);
  color: var(--ink-700);
  padding: 10px 16px;
  border-radius: var(--r-sm);
  transition: background var(--dur-fast) var(--ease), color var(--dur-fast) var(--ease);
}
#nav_ul .subMenu li a:hover {
  background: var(--bg-50);
  color: var(--brand-600);
}

/* ---- Header CTA ---- */
.header-cta {
  flex: none;
  height: 40px;
  padding: 0 20px;
  border-radius: var(--r-full);
  background: var(--brand-600);
  color: #fff;
  font-size: var(--text-sm);
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  transition: background var(--dur) var(--ease);
}
.header-cta:hover { background: var(--brand-700); }

/* ---- Hamburger (mobile) ---- */
.hamburger-button {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  padding: 8px;
  flex: none;
  z-index: calc(var(--z-overlay) + 1);
}
.hamburger-button .hamburger-line {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--ink-900);
  border-radius: 2px;
  transition: transform var(--dur) var(--ease), opacity var(--dur) var(--ease);
}
.hamburger-button.is-open .hamburger-line:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.hamburger-button.is-open .hamburger-line:nth-child(2) { opacity: 0; }
.hamburger-button.is-open .hamburger-line:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ---- Mobile menu overlay ---- */
@media (max-width: 820px) {
  #header_containner > nav { gap: var(--sp-4); }
  .header-cta { display: none; }
  .hamburger-button { display: flex; margin-left: auto; }

  #nav_ul {
    position: fixed;
    inset: 0;
    top: var(--header-h);
    margin: 0;
    flex-direction: column;
    align-items: flex-start;
    justify-content: flex-start;
    gap: 0;
    padding: var(--sp-8) var(--container-pad);
    background: var(--bg-0);
    overflow-y: auto;
    opacity: 0;
    visibility: hidden;
    transition: opacity var(--dur) var(--ease), visibility var(--dur) var(--ease);
    z-index: var(--z-overlay);
  }
  #nav_ul.is-open { opacity: 1; visibility: visible; }

  #nav_ul > li.mainMenu {
    height: auto;
    width: 100%;
    display: block;
    border-bottom: 1px solid var(--line-200);
    padding: var(--sp-4) 0;
  }
  #nav_ul > li.mainMenu > a {
    height: auto;
    font-size: 24px;
    font-weight: 700;
    color: var(--ink-900);
  }
  #nav_ul > li.mainMenu > a::after { display: none; }

  #nav_ul .subMenu {
    position: static;
    transform: none;
    opacity: 1;
    visibility: visible;
    border: 0;
    box-shadow: none;
    padding: var(--sp-2) 0 0;
    min-width: 0;
  }
  #nav_ul .subMenu li a {
    font-size: 17px;
    color: var(--ink-500);
    padding: 8px 0;
  }
  #nav_ul .subMenu li a:hover { background: none; }
}