/* site-nav.css — shared header (with Research and Books & Guides dropdowns) and footer.
   Structure: Preeyam Kumar Prasad, Header/Footer recommendation, 6 Oct 2026. */

/* ---------------- header ---------------- */
.snav {
  position: sticky; top: 0; z-index: 1000;
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
  padding: 12px clamp(16px, 4vw, 44px);
  background: rgba(7, 12, 24, .9); backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--card-border);
  font-family: var(--font-display);
}
.snav--overlay { position: fixed; left: 0; right: 0; background: rgba(7, 12, 24, .55); border-bottom-color: transparent; transition: background .3s, border-color .3s; }
.snav--overlay.scrolled { background: rgba(7, 12, 24, .9); border-bottom-color: var(--card-border); }
.snav-logo { display: flex; align-items: center; gap: 10px; flex-shrink: 0; text-decoration: none; }
.snav-logo .mark {
  font-weight: 700; font-size: 14px; color: #04231e;
  background: linear-gradient(135deg, var(--teal), #6ee7d8);
  width: 34px; height: 34px; border-radius: 10px; display: grid; place-items: center;
}
.snav-logo .word { font-weight: 600; color: var(--text); font-size: 14.5px; }
.snav-logo .dot { color: var(--teal); }

.snav-list { --snav-gap: clamp(6px, 1.3vw, 20px); display: flex; align-items: center; gap: var(--snav-gap); list-style: none; margin: 0; padding: 0; }
.snav-item { position: relative; }
.snav-item > a, .snav-sub-btn {
  display: inline-flex; align-items: center; gap: 6px;
  font: 500 14px/1 var(--font-display); color: var(--muted); text-decoration: none;
  background: none; border: 0; cursor: pointer; padding: 10px 6px; border-radius: 8px;
  transition: color .2s;
}
.snav-item > a:hover, .snav-sub-btn:hover, .snav-item.on > a, .snav-item.on > .snav-sub-btn,
.snav-item > a[aria-current="page"] { color: var(--text); }
.snav-item.on > a::after, .snav-item.on > .snav-sub-btn::after {
  content: ""; position: absolute; left: 6px; right: 6px; bottom: 2px; height: 2px; border-radius: 2px; background: var(--teal);
}
.snav-chev { width: 7px; height: 7px; border-right: 1.6px solid currentColor; border-bottom: 1.6px solid currentColor; transform: translateY(-2px) rotate(45deg); transition: transform .2s; }
.snav-sub-btn[aria-expanded="true"] .snav-chev { transform: translateY(1px) rotate(225deg); }
.snav-sub-btn:focus-visible, .snav-item > a:focus-visible, .snav-sub a:focus-visible, .snav-cta:focus-visible {
  outline: 2px solid var(--teal); outline-offset: 2px;
}

/* dropdown panel (desktop) */
.snav-sub {
  position: absolute; top: calc(100% + 6px); left: -8px; min-width: 210px;
  list-style: none; margin: 0; padding: 8px;
  background: #0d1529; border: 1px solid var(--card-border); border-radius: 14px;
  box-shadow: 0 18px 40px rgba(0, 0, 0, .45);
  opacity: 0; visibility: hidden; transform: translateY(-4px); transition: opacity .18s, transform .18s, visibility .18s;
}
.snav-sub::before { content: ""; position: absolute; left: 0; right: 0; top: -10px; height: 10px; } /* hover bridge */
.snav-sub a {
  display: block; padding: 10px 12px; border-radius: 9px;
  font: 500 14px/1.2 var(--font-display); color: var(--muted); text-decoration: none;
}
.snav-sub a:hover, .snav-sub a[aria-current="page"] { color: var(--text); background: rgba(45, 212, 191, .1); }
.snav-sub a[aria-current="page"] { box-shadow: inset 2px 0 0 var(--teal); }
.has-sub.open > .snav-sub { opacity: 1; visibility: visible; transform: none; }
@media (hover: hover) and (min-width: 1021px) {
  .has-sub:hover > .snav-sub { opacity: 1; visibility: visible; transform: none; }
  /* keyboard users open panels with the button (Enter/Space); Escape closes them */
}

/* the one call to action, visually distinct */
.snav-item > a.snav-cta {
  display: inline-flex; align-items: center; gap: 6px; margin-left: 6px;
  font: 600 14px/1 var(--font-display); color: var(--amber); text-decoration: none;
  padding: 10px 18px; border-radius: 999px; border: 1.5px solid var(--amber);
  transition: background .2s, color .2s;
}
.snav-item > a.snav-cta:hover { background: var(--amber); color: #1c1503; }

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

/* ---------------- mobile: same hierarchy, + / − groups ---------------- */
@media (max-width: 1020px) {
  .snav-toggle { display: block; }
  .snav-menu {
    position: absolute; top: 100%; left: 0; right: 0;
    background: #070c18; border-bottom: 1px solid var(--card-border); box-shadow: 0 18px 30px rgba(0,0,0,.5);
    max-height: 0; overflow: hidden; transition: max-height .35s ease;
  }
  .snav-menu.open { max-height: calc(100vh - 60px); overflow-y: auto; }
  .snav-list { flex-direction: column; align-items: stretch; gap: 0; padding: 6px 0 14px; }
  .snav-item > a, .snav-sub-btn { width: 100%; justify-content: space-between; padding: 14px 26px; font-size: 15.5px; border-radius: 0; }
  .snav-item.on > a::after, .snav-item.on > .snav-sub-btn::after { display: none; }
  .snav-chev { border: 0; transform: none; width: auto; height: auto; }
  .snav-chev::before { content: "+"; font-size: 20px; line-height: 1; }
  .snav-sub-btn[aria-expanded="true"] .snav-chev { transform: none; }
  .snav-sub-btn[aria-expanded="true"] .snav-chev::before { content: "−"; }
  .snav-sub {
    position: static; min-width: 0; padding: 0 0 6px; border: 0; border-radius: 0; box-shadow: none;
    background: transparent; opacity: 1; visibility: visible; transform: none; display: none;
  }
  .has-sub.open > .snav-sub { display: block; }
  .snav-sub a { padding: 12px 26px 12px 44px; font-size: 15px; border-radius: 0; }
  .snav-cta-item { padding: 12px 26px 4px; }
  .snav-item > a.snav-cta { margin: 0; width: auto; justify-content: center; padding: 12px 22px; }
}
@media (max-width: 1240px) and (min-width: 1021px) { .snav-item > a, .snav-sub-btn { font-size: 13.5px; } .snav-list { --snav-gap: 8px; } .snav-logo .word { display: none; } }

/* ---------------- footer ---------------- */
.sfoot {
  margin-top: clamp(50px, 8vw, 90px);
  border-top: 1px solid var(--card-border);
  background: rgba(255, 255, 255, .015);
  font-family: var(--font-body); color: var(--muted);
}
.sfoot-grid {
  max-width: 1160px; margin: 0 auto; padding: clamp(36px, 5vw, 56px) clamp(20px, 5vw, 40px) 30px;
  display: grid; grid-template-columns: 1.35fr 1fr 1fr 1.25fr; gap: clamp(24px, 4vw, 48px);
}
.sfoot a { color: var(--muted); text-decoration: none; transition: color .2s; }
.sfoot a:hover { color: var(--teal); }
.sfoot-name { font: 700 18px/1.2 var(--font-display); color: var(--text) !important; }
.sfoot-tag { margin: 6px 0 10px; font: 500 13.5px/1.4 var(--font-display); color: var(--teal); }
.sfoot-about { font-size: 14px; line-height: 1.65; margin: 0 0 16px; }
.sfoot-social { display: flex; gap: 10px; list-style: none; margin: 0; padding: 0; }
.sfoot-social a { display: grid; place-items: center; width: 36px; height: 36px; border-radius: 10px; border: 1px solid var(--card-border); }
.sfoot-social a:hover { border-color: var(--teal); }
.sfoot-h { margin: 0 0 12px; font: 600 14px/1.3 var(--font-display); color: var(--text); letter-spacing: .2px; }
.sfoot-col ul { list-style: none; margin: 0; padding: 0; }
.sfoot-col li { margin: 0 0 9px; font-size: 14px; line-height: 1.4; }
.sfoot-col li ul { margin: 8px 0 0; padding-left: 12px; border-left: 1px solid var(--card-border); }
.sfoot-col li li { margin-bottom: 7px; font-size: 13.5px; }
.sfoot-book p { font-size: 14px; line-height: 1.6; margin: 0 0 14px; }
.sfoot-btn {
  display: inline-flex; align-items: center; gap: 6px;
  font: 600 14px/1 var(--font-display); color: #1c1503 !important; background: var(--amber);
  padding: 11px 18px; border-radius: 999px;
}
.sfoot-btn:hover { filter: brightness(1.08); }
.sfoot-sample { display: block; margin-top: 12px; font-size: 13.5px; }
.sfoot-bar {
  max-width: 1160px; margin: 0 auto; padding: 18px clamp(20px, 5vw, 40px) 26px;
  display: flex; flex-wrap: wrap; justify-content: space-between; gap: 10px;
  border-top: 1px solid var(--card-border); font-size: 13px;
}
.sfoot-bar p { margin: 0; }
@media (max-width: 900px) { .sfoot-grid { grid-template-columns: 1fr 1fr; } }
@media (max-width: 560px) { .sfoot-grid { grid-template-columns: 1fr; } .sfoot-bar { flex-direction: column; } }
@media print { .snav, .sfoot { display: none; } }
.sfoot-prof { display: inline-flex; align-items: center; gap: 9px; }
.sfoot-prof svg { flex: none; opacity: .9; }
.sfoot-ext { font-size: 12px; opacity: .8; }
.sfoot-legal a + .sfoot-sep { margin: 0 10px; opacity: .5; }
.sfoot-sep { margin: 0 10px; opacity: .5; }

/* ---------- Preeyam's updated designs (Header_Menu.png / Footer_Menu.png, 9 Oct 2026) ---------- */
@media (min-width: 1021px) {
  /* thin dividers between menu items, none before the CTA */
  .snav-list > .snav-item + .snav-item:not(.snav-cta-item)::before {
    content: ""; position: absolute; left: calc(var(--snav-gap) / -2 - .5px); top: 50%;
    width: 1px; height: 16px; transform: translateY(-50%); background: rgba(255, 255, 255, .16);
  }
}
.sfoot { background: #071020; }
.sfoot a, .sfoot-about, .sfoot-desc, .sfoot-book p { color: #b9cde6; }
.sfoot-col li.sfoot-desc { font-size: 13.5px; }
.sfoot a:hover { color: var(--teal); }
.sfoot-prof, .sfoot-legal a { color: #86c5fb !important; }
.sfoot-prof:hover, .sfoot-legal a:hover { color: var(--teal) !important; }
.sfoot-grid { grid-template-columns: 1.3fr 1fr 1fr .9fr 1.25fr; max-width: 1240px; }
.sfoot-bar { max-width: 1240px; align-items: center; }
.sfoot-bar-right { display: flex; align-items: center; gap: 18px; flex-wrap: wrap; }
@media (max-width: 1100px) { .sfoot-grid { grid-template-columns: 1fr 1fr 1fr; } .sfoot-brand { grid-column: 1 / -1; } }
@media (max-width: 700px) { .sfoot-grid { grid-template-columns: 1fr 1fr; } }
@media (max-width: 480px) { .sfoot-grid { grid-template-columns: 1fr; } }