/* Cross-page navigation — mobile-first hamburger drawer that expands to a
   horizontal row on tablet (>= 880px). Loaded by every page in the bundle.
   Variables come from the host page's design tokens; defaults kick in when
   the host has not declared them. */

:root {
  --topnav-h: 56px;
  --topnav-bg: var(--bg, #ffffff);
  --topnav-line: var(--line, #e6e6e6);
}

/* Skip link for keyboard / screen-reader users — hidden until focused. */
.skip-link {
  position: absolute;
  left: -9999px;
  top: auto;
  width: 1px;
  height: 1px;
  overflow: hidden;
}
.skip-link:focus {
  position: fixed;
  left: 8px;
  top: 8px;
  z-index: 200;
  width: auto;
  height: auto;
  padding: 8px 12px;
  background: var(--accent, #2563eb);
  color: #fff;
  border-radius: 6px;
  text-decoration: none;
  font-weight: 600;
}

.topnav {
  position: sticky;
  top: 0;
  z-index: 60;
  background: color-mix(in srgb, var(--topnav-bg) 92%, transparent);
  -webkit-backdrop-filter: saturate(140%) blur(8px);
  backdrop-filter: saturate(140%) blur(8px);
  border-bottom: 1px solid var(--topnav-line);
  padding: 8px max(16px, env(safe-area-inset-right, 0)) 8px max(16px, env(safe-area-inset-left, 0));
  display: flex;
  align-items: center;
  gap: 8px;
  min-height: var(--topnav-h);
}

.topnav .brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  color: var(--ink, #0a0a0a);
  text-decoration: none;
  font-size: 0.975rem;
  letter-spacing: -0.01em;
  flex-shrink: 0;
  min-height: 36px;
  padding: 6px 4px;
}

.topnav .brand .dot {
  display: inline-block;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--accent, #2563eb);
  flex-shrink: 0;
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--accent, #2563eb) 18%, transparent);
}

/* Hamburger toggle — mobile only. */
.topnav .nav-toggle {
  margin-left: auto;
  display: inline-flex;
  flex-direction: column;
  justify-content: center;
  gap: 4px;
  width: 44px;
  height: 44px;
  padding: 10px;
  border: 1px solid var(--line, #e6e6e6);
  border-radius: 10px;
  background: var(--bg-soft, #fafafa);
  cursor: pointer;
  color: inherit;
}
.topnav .nav-toggle:focus-visible {
  outline: 2px solid var(--accent, #2563eb);
  outline-offset: 2px;
}
.topnav .nav-toggle-bar {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--ink, #0a0a0a);
  border-radius: 2px;
  transition: transform 200ms ease, opacity 200ms ease;
}
.topnav .nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(1) {
  transform: translateY(6px) rotate(45deg);
}
.topnav .nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(2) {
  opacity: 0;
}
.topnav .nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(3) {
  transform: translateY(-6px) rotate(-45deg);
}

/* Nav drawer — full-width sheet on mobile, inline row on tablet+. */
.topnav .nav-links {
  display: none;
  position: absolute;
  left: 0;
  right: 0;
  top: var(--topnav-h);
  flex-direction: column;
  gap: 2px;
  padding: 12px;
  background: var(--bg, #ffffff);
  border-bottom: 1px solid var(--line, #e6e6e6);
  box-shadow: 0 6px 24px rgba(0, 0, 0, 0.08);
  max-height: calc(100vh - var(--topnav-h));
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
}

.topnav .nav-toggle[aria-expanded="true"] + .nav-links {
  display: flex;
}

.topnav .nav-links a.np {
  display: block;
  padding: 12px 14px;
  border-radius: 8px;
  color: var(--ink-soft, #3f3f46);
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 500;
  min-height: 44px;
  line-height: 1.4;
}
.topnav .nav-links a.np:hover {
  background: var(--bg-soft, #fafafa);
  color: var(--ink, #0a0a0a);
}
.topnav .nav-links a.np:focus-visible {
  outline: 2px solid var(--accent, #2563eb);
  outline-offset: 2px;
}
.topnav .nav-links a.np[aria-current="page"] {
  background: var(--accent-soft, #e0eaff);
  color: var(--accent, #2563eb);
  font-weight: 600;
}

@media (min-width: 880px) {
  .topnav {
    padding: 8px max(24px, env(safe-area-inset-right, 0)) 8px max(24px, env(safe-area-inset-left, 0));
    gap: 8px;
  }
  .topnav .nav-toggle {
    display: none;
  }
  .topnav .nav-links {
    display: flex !important;
    position: static;
    flex-direction: row;
    flex-wrap: wrap;
    gap: 4px;
    padding: 0;
    background: transparent;
    border: none;
    box-shadow: none;
    max-height: none;
    overflow: visible;
    flex: 1;
    justify-content: flex-end;
  }
  .topnav .nav-links a.np {
    padding: 6px 12px;
    font-size: 0.9rem;
    min-height: 36px;
    display: inline-flex;
    align-items: center;
  }
}

@media print {
  .topnav,
  .nav-toggle,
  .nav-links {
    display: none !important;
  }
  .skip-link {
    display: none !important;
  }
}