/* ══════════════════════════════════════════════════════
   nav.css
   Shared navigation stylesheet — Deborah R. Fowler course pages
   Load on every page alongside the page-specific stylesheet.
   ══════════════════════════════════════════════════════ */

/* ── NAV TOKENS ── */
:root {
  --nav-h:     58px;
  --max:       1140px;
  --sidebar-w: 210px;
  --radius:    5px;
  --mono:      'DM Mono', monospace;
  --serif:     'Libre Baskerville', Georgia, serif;
  --sans:      'Instrument Sans', system-ui, sans-serif;
}

/* ── BASE ── */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: calc(var(--nav-h) + 12px); }
body { margin: 0; padding: 0; }

/* ── TOP NAV ── */
.top-nav {
  position: sticky; top: 0; z-index: 200;
  background: #3d2a52;
  border-bottom: 1px solid #5a3d72;
  box-shadow: 0 2px 16px rgba(0,0,0,.25);
}
.nav-inner {
  max-width: var(--max); margin: 0 auto;
  height: var(--nav-h);
  display: flex; align-items: center;
  padding: 0 clamp(1rem, 4vw, 2rem); gap: 1.5rem;
}
.nav-brand {
  font-family: var(--serif); font-size: .9rem; color: rgba(255,255,255,.9);
  font-style: italic; white-space: nowrap; flex-shrink: 0; letter-spacing: .01em;
}
.nav-links {
  display: flex; gap: 0; list-style: none; margin-left: auto; align-items: center;
}
.nav-links li { position: relative; }
.nav-links > li > a {
  display: block; padding: .4rem .8rem;
  font-size: .82rem; letter-spacing: .02em; color: rgba(255,255,255,.75);
  border-radius: var(--radius); transition: color .15s, background .15s;
  font-weight: 500; text-decoration: none;
}
.nav-links > li > a:hover { background: rgba(255,255,255,.1); color: #fff; }
.nav-links > li.active > a { font-weight: 700; color: var(--accent); background: rgba(255,255,255,.08); }

/* ── DROPDOWNS ── */
.dropdown > a::after { content: ' ▾'; font-size: .9rem; opacity: .7; margin-left: .2rem; }
.dropdown-menu {
  visibility: hidden; opacity: 0; pointer-events: none;
  position: absolute; top: calc(100% + 8px); left: 0;
  min-width: 200px; background: var(--bg-wash);
  border: 1px solid var(--border-mid); border-radius: 8px;
  box-shadow: 0 12px 36px rgba(0,0,0,.4); padding: .4rem 0; z-index: 300;
  transform: translateY(-6px);
  transition: opacity .18s ease, transform .18s ease, visibility .18s;
  list-style: none;
}
.dropdown.open .dropdown-menu {
  visibility: visible; opacity: 1; pointer-events: auto; transform: translateY(0);
}
.dropdown-label {
  display: block; padding: .5rem 1rem .2rem;
  font-family: var(--mono); font-size: .58rem; letter-spacing: .12em;
  text-transform: uppercase; color: var(--text-dim);
}
.dropdown-divider { height: 1px; background: var(--border); margin: .4rem .75rem; }
.dropdown-menu li a {
  display: flex; align-items: center; gap: .6rem;
  padding: .5rem 1rem; font-size: .8rem; color: var(--text);
  transition: color .1s, background .1s; white-space: nowrap; text-decoration: none;
}
.dropdown-menu li a::before { display: none; }
.dropdown-menu li a:hover { color: var(--accent); background: var(--bg-sub); }
.dropdown-menu .sub-item a { padding-left: 2rem; color: var(--text-mid); }
.dropdown-menu .sub-item a::before { content: '↳'; width: auto; height: auto; background: none; color: var(--text-dim); border-radius: 0; }
.dropdown-menu .dim-item a { opacity: .55; }

/* ── ARCHIVED TOGGLE ── */
.archived-toggle-item { list-style: none; }
.archived-toggle {
  display: flex; align-items: center; gap: .4rem;
  width: 100%; padding: .5rem 1rem;
  background: none; border: none; cursor: pointer;
  font-family: var(--mono); font-size: .58rem; letter-spacing: .1em;
  text-transform: uppercase; color: var(--text-dim); transition: color .1s;
}
.archived-toggle:hover,
.archived-toggle[aria-expanded="true"] { color: var(--text-mid); }
.archived-courses { list-style: none; }
.archived-courses ul { list-style: none; padding: 0; margin: 0; }
.archived-courses ul li a {
  display: flex; align-items: center; gap: .6rem;
  padding: .5rem 1rem .5rem 1.5rem;
  font-size: .82rem; color: var(--text-mid);
  opacity: .7; transition: color .1s, background .1s;
  white-space: nowrap; text-decoration: none;
}
.archived-courses ul li a:hover { color: var(--accent); background: var(--bg-sub); opacity: 1; }

/* ── THEME BUTTON ── */
.theme-btn {
  min-width: 76px;        /* add this */
  text-align: center;     /* add this */
  margin-left: .5rem; background: rgba(255,255,255,.08);
  border: 1px solid rgba(255,255,255,.2);
  border-radius: 100px; padding: .3rem .7rem; flex-shrink: 0;
  font-family: var(--mono); font-size: .68rem; color: rgba(255,255,255,.7);
  cursor: pointer; transition: border-color .15s, color .15s, background .15s; white-space: nowrap;
}
.theme-btn:hover { border-color: rgba(255,255,255,.4); color: #fff; background: rgba(255,255,255,.12); }

/* ── HAMBURGER ── */
.hamburger {
  display: none; margin-left: auto;
  background: none; border: none; cursor: pointer;
  padding: .4rem; color: rgba(255,255,255,.8);
  flex-direction: column; justify-content: center; gap: 5px;
}
.hamburger span {
  display: block; width: 22px; height: 2px;
  background: currentColor; border-radius: 2px;
  transition: transform .25s, opacity .25s;
}
.hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; }
.hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ── MOBILE MENU ── */
.mobile-menu {
  display: none;
  position: fixed; top: var(--nav-h); left: 0; right: 0; bottom: 0;
  background: #3d2a52; z-index: 199; overflow-y: auto;
  padding: 1rem 0 2rem;
  transform: translateX(100%); transition: transform .28s ease;
}
.mobile-menu.open { transform: translateX(0); }
.mobile-menu-item {
  display: block; padding: .85rem 1.5rem;
  font-size: .95rem; font-weight: 500; color: rgba(255,255,255,.8);
  border-bottom: 1px solid rgba(255,255,255,.08);
  transition: color .15s, background .15s; text-decoration: none;
}
.mobile-menu-item:hover { color: #fff; background: rgba(255,255,255,.07); }
.mobile-menu-item.indent { padding-left: 2.75rem; }
.mobile-menu-item.dim { opacity: .55; }
.mobile-menu-item.italic { font-style: italic; opacity: .75; }
.mobile-menu-label {
  display: block; padding: 1.2rem 1.5rem .4rem;
  font-family: var(--mono); font-size: .58rem; letter-spacing: .12em;
  text-transform: uppercase; color: rgba(255,255,255,.35);
}
.mobile-menu-divider { height: 1px; background: rgba(255,255,255,.1); margin: .5rem 1rem; }
.theme-btn-mobile {
  display: block; width: 100%; text-align: left;
  background: none; border: none; cursor: pointer;
  padding: .85rem 1.5rem;
  font-family: var(--mono); font-size: .75rem; letter-spacing: .05em;
  color: rgba(255,255,255,.7);
  transition: color .15s, background .15s;
}
.theme-btn-mobile:hover { color: #fff; background: rgba(255,255,255,.07); }

/* ── FOOTER ── */
footer { background: var(--bg-wash); border-top: 1px solid var(--border); }
.footer-inner {
  max-width: var(--max); margin: 0 auto;
  padding: 1.25rem clamp(1rem, 4vw, 2.5rem);
  display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: .75rem;
}
.footer-copy { font-family: var(--mono); font-size: .62rem; letter-spacing: .05em; color: var(--text-dim); }
.footer-links { display: flex; gap: .35rem; }
.footer-links a {
  font-family: var(--mono); font-size: .62rem; color: var(--text-dim);
  padding: .25rem .5rem; border: 1px solid var(--border); border-radius: var(--radius);
  transition: color .12s, border-color .12s; text-decoration: none;
}
.footer-links a:hover { color: var(--text); border-color: var(--border-mid); }

/* ── RESPONSIVE ── */
@media (max-width: 540px) {
  .nav-links > li { display: none; }
  .nav-links > li.always-show { display: flex; align-items: center; }
  .hamburger { display: flex; }
  .mobile-menu { display: block; }
}