/* =========================================================
   ANATOMARK NAVIGATION
   ========================================================= */

.site-header {

  position: relative;

  z-index: 100;

  width: 100%;

  background:
    rgba(5, 15, 17, 0.78);

  border-bottom:
    1px solid
    rgba(0, 229, 199, 0.07);

  backdrop-filter:
    blur(18px);

  -webkit-backdrop-filter:
    blur(18px);

}


.header-inner {

  width:
    min(
      1400px,
      calc(100% - 80px)
    );

  height: 88px;

  margin: 0 auto;

  display: flex;

  align-items: center;

  justify-content: space-between;

}


/* =========================================================
   BRAND
   ========================================================= */

.brand {

  display: inline-flex;

  align-items: center;

  flex-shrink: 0;

  text-decoration: none;

}


.brand-logo {

  display: block;

  width: auto;

  height: 32px;

  width: auto;

  object-fit: contain;

}

.brand { gap: 10px; }

.brand-text {
  font-weight: 800;
  font-size: 19px;
  letter-spacing: -0.01em;
  color: var(--color-white, #fff);
}

.brand-text span { color: var(--color-primary); }


/* =========================================================
   DESKTOP NAVIGATION
   ========================================================= */

.desktop-nav {

  display: flex;

  align-items: center;

  justify-content: flex-end;

  gap: 34px;

}


.nav-link {

  position: relative;

  display: inline-flex;

  align-items: center;

  height: 88px;

  color:
    rgba(235, 255, 252, 0.62);

  font-size: 12px;

  font-weight: 500;

  letter-spacing: 0.04em;

  text-decoration: none;

  white-space: nowrap;

  transition:
    color 180ms ease;

}


.nav-link::after {

  content: "";

  position: absolute;

  left: 0;

  right: 0;

  bottom: 0;

  height: 2px;

  background: #00e5c7;

  transform:
    scaleX(0);

  transform-origin: center;

  transition:
    transform 180ms ease;

}


.nav-link:hover {

  color: #00e5c7;

}


.nav-link:hover::after {

  transform:
    scaleX(1);

}


.nav-link.active {

  color: #00e5c7;

}


.nav-link.active::after {

  transform:
    scaleX(1);

}


/* =========================================================
   MOBILE MENU BUTTON
   ========================================================= */

.mobile-menu-button {

  /*
   * Hidden by default.
   *
   * This guarantees it does NOT appear
   * on desktop.
   */

  display: none;

  width: 42px;

  height: 42px;

  padding: 0;

  border: 0;

  background: transparent;

  cursor: pointer;

  flex-direction: column;

  align-items: center;

  justify-content: center;

  gap: 5px;

}


.mobile-menu-button span {

  display: block;

  width: 22px;

  height: 1.5px;

  background: #00e5c7;

  transition:
    transform 180ms ease,
    opacity 180ms ease;

}


/* =========================================================
   MOBILE NAV
   ========================================================= */

.mobile-nav {

  /*
   * Hidden on desktop.
   */

  display: none;

}


/* =========================================================
   TABLET
   ========================================================= */

@media (max-width: 1050px) and (min-width: 768px) {

  .header-inner {

    width:
      calc(100% - 48px);

  }

  .desktop-nav {

    gap: 22px;

  }

  .nav-link {

    font-size: 11px;

  }

}
/* =========================================================
   MOBILE
   ========================================================= */

@media (max-width: 767px) {

  .header-inner {
    width: calc(100% - 32px);
    height: 68px;
  }


  .brand-logo { height: 28px; }
  .brand-text { font-size: 17px; }


  /* -----------------------------------------
     DESKTOP NAVIGATION
     ----------------------------------------- */

  .desktop-nav {
    display: none;
  }


  /* -----------------------------------------
     HAMBURGER
     ----------------------------------------- */

  .mobile-menu-button {
    display: flex;
  }


  /* -----------------------------------------
     MOBILE NAVIGATION
     
     CLOSED BY DEFAULT
     ----------------------------------------- */

  .mobile-nav {
    display: none;

    width: 100%;

    flex-direction: column;

    padding:
      8px 16px 18px;

    background:
      rgba(5, 15, 17, 0.97);

    border-top:
      1px solid
      rgba(0, 229, 199, 0.08);

    box-shadow:
      0 20px 40px
      rgba(0, 0, 0, 0.3);
  }


  /* -----------------------------------------
     OPEN STATE
     ----------------------------------------- */

  .mobile-nav.open {
    display: flex;
  }


  /* -----------------------------------------
     MOBILE LINKS
     ----------------------------------------- */

  .mobile-nav-link {

    display: block;

    padding:
      15px 8px;

    color:
      rgba(235, 255, 252, 0.7);

    font-size: 13px;

    text-decoration: none;

    border-bottom:
      1px solid
      rgba(0, 229, 199, 0.06);
  }


  .mobile-nav-link:last-child {
    border-bottom: 0;
  }


  .mobile-nav-link:hover,
  .mobile-nav-link.active {
    color: #00e5c7;
  }


  /* -----------------------------------------
     HAMBURGER → X
     ----------------------------------------- */

  .mobile-menu-button.active span:nth-child(1) {
    transform:
      translateY(6.5px)
      rotate(45deg);
  }


  .mobile-menu-button.active span:nth-child(2) {
    opacity: 0;
  }


  .mobile-menu-button.active span:nth-child(3) {
    transform:
      translateY(-6.5px)
      rotate(-45deg);
  }

}

/* =========================================================
   BACK BUTTON — one round button, arrow drawn as an SVG so it is
   exactly centred (a text arrow sits low and off-centre, and its
   size depends on the font). 44px is the minimum comfortable tap size.
   ========================================================= */
.back-btn {
  display: inline-flex; align-items: center; justify-content: center;
  flex: 0 0 auto; width: 44px; height: 44px; padding: 0;
  border-radius: 50%;
  border: 1px solid rgba(0, 229, 199, 0.35);
  background: rgba(0, 229, 199, 0.06);
  color: var(--color-primary);
  text-decoration: none; line-height: 0;
  transition: background 150ms ease, border-color 150ms ease;
}
.back-btn svg { display: block; }
.back-btn:hover { background: rgba(0, 229, 199, 0.14); border-color: rgba(0, 229, 199, 0.7); }
.back-btn:focus-visible { outline: 2px solid var(--color-primary); outline-offset: 3px; }
.about-crumb, .marker-crumb, .howto-crumb, .library-crumb, .detail-crumb { gap: 12px; align-items: center; }