/* ═════════════════════════════════════════════════════════════
   NARTON ATLAS — SECTION & TOPIC PAGES (.ap)
   Requires atlas-ui.css. Accent colour comes from --c (group).
═════════════════════════════════════════════════════════════ */

/* ═════════════════ HERO ═════════════════ */
.ap-hero {
  position: relative;
  padding: clamp(1.75rem, 4vw, 2.75rem) 0 clamp(1.75rem, 4vw, 2.5rem);
  border-bottom: 1px solid var(--border);
  overflow: hidden;
  isolation: isolate;
}
.ap-hero-bg { position: absolute; inset: 0; z-index: -1; pointer-events: none; }
.ap-grid {
  position: absolute; inset: 0;
  background-image:
    linear-gradient(color-mix(in srgb, var(--c) 7%, transparent) 1px, transparent 1px),
    linear-gradient(90deg, color-mix(in srgb, var(--c) 7%, transparent) 1px, transparent 1px);
  background-size: 44px 44px;
  mask-image: radial-gradient(ellipse 60% 80% at 75% 30%, #000 25%, transparent 75%);
  -webkit-mask-image: radial-gradient(ellipse 60% 80% at 75% 30%, #000 25%, transparent 75%);
}
.ap-blob {
  position: absolute; border-radius: 50%;
  filter: blur(70px); opacity: .5;
  animation: hpFloat 18s ease-in-out infinite alternate;
}
.ap-blob--a { width: 420px; height: 420px; background: color-mix(in srgb, var(--c) 30%, #fff); top: -180px; right: 4%; }
.ap-blob--b { width: 300px; height: 300px; background: color-mix(in srgb, var(--c) 16%, #fff); bottom: -170px; left: 18%; animation-delay: -8s; }

/* Breadcrumbs */
.ap-crumbs {
  display: flex; flex-wrap: wrap; align-items: center; gap: .45rem;
  font-size: .82rem; color: var(--muted);
  margin-bottom: 1.6rem;
}
.ap-crumbs a {
  color: var(--muted) !important;
  padding: .2rem .5rem; margin: 0 -.25rem;
  border-radius: 7px;
  transition: color .2s, background .2s;
}
.ap-crumbs a:hover { color: var(--c) !important; background: var(--c-soft); }
.ap-crumbs > i { font-size: .65rem; opacity: .6; }
.ap-crumbs [aria-current] { color: var(--ink); font-weight: 500; }

/* Section hero layout */
.ap-hero-main { display: flex; align-items: center; gap: 1.6rem; margin-bottom: 1.6rem; }

.ap-emblem {
  position: relative; flex-shrink: 0;
  width: 112px; height: 112px;
  display: grid; place-items: center;
}
.ap-emblem-ring {
  position: absolute; inset: 0; border-radius: 50%;
  border: 1.5px dashed color-mix(in srgb, var(--c) 35%, transparent);
  animation: hpSpin 30s linear infinite;
}
.ap-emblem-ring::after {
  content: ''; position: absolute; top: 8px; right: 12px;
  width: 9px; height: 9px; border-radius: 50%; background: var(--c);
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--c) 18%, transparent);
}
.ap-emblem-ring--2 { inset: -14px; border-style: solid; border-color: color-mix(in srgb, var(--c) 12%, transparent); animation-duration: 48s; animation-direction: reverse; }
.ap-emblem-ring--2::after { top: auto; bottom: 14px; left: 6px; right: auto; width: 7px; height: 7px; opacity: .6; }
.ap-emblem-icon {
  width: 76px; height: 76px; border-radius: 24px;
  display: grid; place-items: center;
  font-size: 2.1rem; color: #fff;
  background: linear-gradient(140deg, color-mix(in srgb, var(--c) 75%, #fff), var(--c) 55%, color-mix(in srgb, var(--c) 75%, #000));
  box-shadow: 0 16px 34px -12px color-mix(in srgb, var(--c) 70%, transparent);
  transform: rotate(-6deg);
  transition: transform .5s var(--ease-out);
}
.ap-emblem:hover .ap-emblem-icon { transform: rotate(0) scale(1.05); }

.ap-eyebrow {
  font-size: .74rem; font-weight: 600; letter-spacing: .14em; text-transform: uppercase;
  color: var(--c); margin-bottom: .35rem;
}
.ap-title {
  font-family: var(--font-display);
  font-size: clamp(2.1rem, 4.6vw, 3.4rem);
  font-weight: 700; letter-spacing: -.025em; line-height: 1.08;
  color: var(--ink); margin: 0 0 .7rem;
}
.ap-stats { display: flex; flex-wrap: wrap; gap: .5rem; }
.ap-stats span {
  font-size: .82rem; color: var(--muted);
  background: rgba(255,255,255,.8);
  border: 1px solid var(--border);
  padding: .3rem .75rem; border-radius: 50px;
  backdrop-filter: blur(6px);
}
.ap-stats b { color: var(--ink); font-weight: 600; }

/* Search inside hero */
.ap-search {
  position: relative;
  display: flex; align-items: center;
  max-width: 560px;
  background: var(--paper);
  border: 1.5px solid var(--border);
  border-radius: 16px;
  padding: .2rem .6rem .2rem 2.9rem;
  box-shadow: 0 10px 30px -14px rgba(15,23,42,.2);
  transition: border-color .25s, box-shadow .25s;
}
.ap-search:focus-within {
  border-color: var(--c);
  box-shadow: 0 0 0 5px color-mix(in srgb, var(--c) 13%, transparent), 0 16px 36px -16px color-mix(in srgb, var(--c) 45%, transparent);
}
.ap-search-icon { position: absolute; left: 1.1rem; color: var(--muted); transition: color .2s; }
.ap-search:focus-within .ap-search-icon { color: var(--c); }
.ap-search-input {
  flex: 1; min-width: 0; border: 0; outline: 0; background: transparent;
  font: 400 .98rem var(--font-body); color: var(--ink);
  padding: .78rem .25rem;
}
.ap-search-input::placeholder { color: #94a3b8; }
.ap-kbd {
  font: 500 .72rem var(--font-body); color: var(--muted);
  background: var(--bg); border: 1px solid var(--border); border-bottom-width: 2px;
  border-radius: 6px; padding: .12rem .45rem; box-shadow: none;
}
.ap-search:focus-within .ap-kbd { opacity: 0; }

/* Sibling strip */
.ap-siblings {
  display: flex; align-items: center; gap: 1rem;
  margin-top: 1.6rem;
}
.ap-siblings-label {
  flex-shrink: 0;
  font-size: .72rem; font-weight: 600; letter-spacing: .08em; text-transform: uppercase;
  color: var(--muted);
}
.ap-sibling-track {
  display: flex; gap: .45rem;
  overflow-x: auto; scrollbar-width: none;
  padding: .25rem .1rem;
  mask-image: linear-gradient(90deg, transparent, #000 14px, #000 calc(100% - 28px), transparent);
  -webkit-mask-image: linear-gradient(90deg, transparent, #000 14px, #000 calc(100% - 28px), transparent);
  scroll-behavior: smooth;
}
.ap-sibling-track::-webkit-scrollbar { display: none; }
.ap-sibling {
  flex-shrink: 0;
  display: inline-flex; align-items: center; gap: .4rem;
  font-size: .82rem; font-weight: 500;
  color: var(--ink) !important;
  background: rgba(255,255,255,.85);
  border: 1px solid var(--border);
  padding: .38rem .8rem; border-radius: 50px;
  transition: border-color .2s, color .2s, background .2s, transform .2s var(--ease-out);
}
.ap-sibling i { color: var(--c); }
.ap-sibling small {
  font-size: .7rem; font-weight: 600;
  color: var(--muted); background: var(--bg);
  padding: .05rem .4rem; border-radius: 50px;
}
.ap-sibling:hover { border-color: var(--c); color: var(--c) !important; transform: translateY(-1px); }
.ap-sibling.is-empty { color: var(--muted) !important; }
.ap-sibling.is-current {
  background: var(--c); border-color: var(--c); color: #fff !important;
}
.ap-sibling.is-current i { color: #fff; }
.ap-sibling.is-current small { background: rgba(255,255,255,.22); color: #fff; }

/* ═════════════════ SECTIONS ═════════════════ */
.ap-section { padding: clamp(2.5rem, 5vw, 3.75rem) 0; scroll-margin-top: 64px; }
.ap-section--tint {
  background: linear-gradient(180deg, var(--paper), var(--bg));
  border-top: 1px solid var(--border);
}
.ap-section--last { padding-top: 0; padding-bottom: clamp(3rem, 6vw, 4.5rem); }
.ap-section--tint + .ap-section--last { padding-top: 1rem; }

/* Switch */
.ap-switch {
  display: inline-flex; align-items: center; gap: .6rem;
  font-size: .85rem; color: var(--muted);
  cursor: pointer; user-select: none;
}
.ap-switch input { position: absolute; opacity: 0; pointer-events: none; }
.ap-switch-track {
  position: relative; width: 38px; height: 22px; border-radius: 50px;
  background: var(--border);
  transition: background .25s;
}
.ap-switch-thumb {
  position: absolute; top: 3px; left: 3px;
  width: 16px; height: 16px; border-radius: 50%;
  background: #fff; box-shadow: 0 1px 3px rgba(0,0,0,.2);
  transition: transform .3s var(--ease-out);
}
.ap-switch input:checked + .ap-switch-track { background: var(--c); }
.ap-switch input:checked + .ap-switch-track .ap-switch-thumb { transform: translateX(16px); }
.ap-switch input:focus-visible + .ap-switch-track { outline: 2px solid var(--c); outline-offset: 2px; }
.ap-switch:hover { color: var(--ink); }

.ap-match-note { font-size: .9rem; color: var(--muted); margin: -1rem 0 1.25rem; }
.ap-match-note b { color: var(--ink); }
.ap-match-note a { color: var(--c) !important; font-weight: 500; }

/* Topic grid */
.ap-topics {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: .9rem;
}
.ap-topic {
  position: relative; isolation: isolate; overflow: hidden;
  display: flex; align-items: center; gap: 1rem;
  padding: 1.05rem 1.1rem;
  background: var(--paper);
  border: 1px solid var(--border);
  border-radius: 16px;
  color: var(--ink) !important;
  transition: transform .35s var(--ease-out), box-shadow .3s, border-color .3s, opacity .3s;
}
.ap-topic[hidden] { display: none; }
.ap-topic::before {   /* spotlight */
  content: ''; position: absolute; inset: 0; z-index: -1;
  background: radial-gradient(220px circle at var(--mx, 50%) var(--my, 50%),
              color-mix(in srgb, var(--c) 11%, transparent), transparent 70%);
  opacity: 0; transition: opacity .3s;
}
.ap-topic:hover {
  transform: translateY(-3px);
  border-color: color-mix(in srgb, var(--c) 40%, transparent);
  box-shadow: 0 16px 32px -20px color-mix(in srgb, var(--c) 60%, transparent);
}
.ap-topic:hover::before { opacity: 1; }
.ap-topic-num {
  flex-shrink: 0;
  display: grid; place-items: center;
  width: 42px; height: 42px; border-radius: 12px;
  font: 700 .85rem var(--font-display);
  color: var(--c); background: var(--c-soft);
  transition: background .3s, color .3s, transform .4s var(--ease-out);
}
.ap-topic:hover .ap-topic-num { background: var(--c); color: #fff; transform: rotate(-6deg) scale(1.05); }
.ap-topic-main { flex: 1; min-width: 0; display: flex; flex-direction: column; gap: .15rem; }
.ap-topic-name {
  font-family: var(--font-display); font-weight: 700; font-size: 1rem; line-height: 1.3;
}
.ap-topic-desc { font-size: .84rem; color: var(--muted); line-height: 1.4; }
.ap-topic-meta { font-size: .76rem; color: var(--muted); margin-top: .2rem; font-weight: 500; }
.ap-topic-bar {
  height: 4px; border-radius: 4px; background: var(--bg);
  margin-top: .45rem; overflow: hidden;
}
.ap-topic-bar span {
  display: block; height: 100%; width: var(--w); border-radius: inherit;
  background: linear-gradient(90deg, color-mix(in srgb, var(--c) 55%, #fff), var(--c));
  transform-origin: left;
  transition: transform 1s var(--ease-out) .25s;
}
html.js .ap-topic.reveal:not(.is-visible) .ap-topic-bar span { transform: scaleX(0); }
.ap-topic-arrow {
  flex-shrink: 0; color: var(--c);
  opacity: 0; transform: translateX(-8px);
  transition: opacity .3s, transform .35s var(--ease-out);
}
.ap-topic:hover .ap-topic-arrow { opacity: 1; transform: none; }

.ap-topic.is-empty { background: color-mix(in srgb, var(--paper) 55%, var(--bg)); border-style: dashed; }
.ap-topic.is-empty .ap-topic-num { background: var(--bg); color: var(--muted); }
.ap-topic.is-empty .ap-topic-name { color: #475569; }
.hide-empty .ap-topic.is-empty { display: none; }

/* Areas: a few headed groups of topics on a subject page */
.ap-area-nav { display: flex; flex-wrap: wrap; gap: .5rem; margin-bottom: 2rem; }
.ap-area-link {
  display: inline-flex; align-items: center; gap: .45rem;
  font-size: .86rem; font-weight: 500;
  color: var(--ink) !important; background: var(--paper);
  border: 1px solid var(--border); border-radius: 50px;
  padding: .42rem .95rem;
  transition: border-color .2s, color .2s;
}
.ap-area-link small {
  font-size: .72rem; font-weight: 600; color: var(--c);
  background: var(--c-soft); border-radius: 50px; padding: .05rem .45rem;
}
.ap-area-link:hover { border-color: var(--c); color: var(--c) !important; }
.ap-area-link[hidden] { display: none; }
.ap-areas { display: flex; flex-direction: column; gap: 2.75rem; }
.ap-area { scroll-margin-top: 90px; }
.ap-area[hidden] { display: none; }
.ap-area-head {
  display: flex; align-items: center; gap: .9rem;
  padding-bottom: .9rem; margin-bottom: 1.1rem;
  border-bottom: 1px solid var(--border);
}
.ap-area-num {
  flex-shrink: 0; display: grid; place-items: center;
  width: 38px; height: 38px; border-radius: 11px;
  font: 700 .95rem var(--font-display);
  color: var(--c); background: var(--c-soft);
}
.ap-area-copy { flex: 1; min-width: 0; }
.ap-area-name { font-family: var(--font-display); font-weight: 700; font-size: 1.25rem; margin: 0; line-height: 1.25; }
.ap-area-desc { font-size: .88rem; color: var(--muted); margin: .1rem 0 0; }
.ap-area-count { flex-shrink: 0; font-size: .8rem; color: var(--muted); font-weight: 500; }
@media (max-width: 575px) { .ap-area-count { display: none; } }
.ap-topics[hidden] { display: none; }

/* Empty states */
.ap-empty {
  text-align: center;
  padding: 3rem 1.5rem;
  background: var(--paper);
  border: 1px dashed var(--border);
  border-radius: 20px;
}
.ap-empty[hidden] { display: none; }
.ap-empty--big { padding: 4rem 1.5rem; }
.ap-empty-icon {
  display: inline-grid; place-items: center;
  width: 64px; height: 64px; border-radius: 20px;
  font-size: 1.7rem; color: var(--c); background: var(--c-soft);
  margin-bottom: 1rem;
  animation: apBob 3s ease-in-out infinite;
}
@keyframes apBob { 50% { transform: translateY(-6px) rotate(-4deg); } }
.ap-empty h3 { font-family: var(--font-display); font-size: 1.3rem; font-weight: 700; margin-bottom: .4rem; }
.ap-empty p { color: var(--muted); max-width: 440px; margin: 0 auto 1.25rem; }
.ap-empty-actions { display: flex; flex-wrap: wrap; justify-content: center; gap: .6rem; }

/* Buttons */
.ap-btn {
  display: inline-flex; align-items: center; justify-content: center; gap: .5rem;
  font: 600 .9rem var(--font-body);
  color: #fff !important; background: var(--c);
  border: 1.5px solid var(--c);
  padding: .72rem 1.2rem; border-radius: 12px;
  box-shadow: 0 10px 24px -12px color-mix(in srgb, var(--c) 70%, transparent);
  transition: transform .25s var(--ease-out), box-shadow .25s, background .2s;
  cursor: pointer;
}
.ap-btn:hover { transform: translateY(-2px); box-shadow: 0 16px 30px -14px color-mix(in srgb, var(--c) 80%, transparent); }
.ap-btn:active { transform: scale(.97); }
.ap-btn i { transition: transform .3s var(--ease-out); }
.ap-btn:hover .bi-arrow-right { transform: translateX(3px); }
.ap-btn:hover .bi-plus-lg { transform: rotate(90deg); }
.ap-btn--sm { font-size: .82rem; padding: .5rem .9rem; border-radius: 10px; }
.ap-btn--ghost {
  background: var(--paper); color: var(--ink) !important;
  border-color: var(--border); box-shadow: none;
}
.ap-btn--ghost:hover { border-color: var(--c); color: var(--c) !important; box-shadow: none; }

/* Suggest strip */
.ap-suggest {
  display: flex; align-items: center; gap: 1.1rem; flex-wrap: wrap;
  padding: 1.25rem 1.4rem;
  background: var(--paper);
  border: 1px solid var(--border);
  border-radius: 18px;
}
.ap-suggest > div { flex: 1; min-width: 220px; }
.ap-suggest-icon {
  display: grid; place-items: center;
  width: 48px; height: 48px; border-radius: 14px;
  background: #fef3c7; color: #b45309; font-size: 1.35rem;
}
.ap-suggest h3 { font-family: var(--font-display); font-size: 1.05rem; font-weight: 700; margin: 0 0 .15rem; }
.ap-suggest p { margin: 0; font-size: .88rem; color: var(--muted); }

/* ═════════════════ TOPIC PAGE ═════════════════ */
.ap-topic-hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 380px);
  gap: 2.5rem; align-items: center;
}
.ap-section-pill {
  display: inline-flex; align-items: center; gap: .45rem;
  font-size: .8rem; font-weight: 600;
  color: var(--c) !important; background: var(--c-soft);
  padding: .32rem .75rem; border-radius: 50px;
  margin-bottom: .9rem;
  transition: background .2s, color .2s;
}
.ap-section-pill:hover { background: var(--c); color: #fff !important; }
.ap-lede { font-size: 1.02rem; line-height: 1.7; color: var(--muted); max-width: 560px; margin-bottom: 1.25rem; }

.ap-pager { display: flex; flex-wrap: wrap; gap: .5rem; }
.ap-pager-btn {
  display: inline-flex; align-items: center; gap: .5rem;
  max-width: 260px;
  font-size: .82rem; font-weight: 500;
  color: var(--muted) !important;
  background: rgba(255,255,255,.8);
  border: 1px solid var(--border);
  padding: .42rem .8rem; border-radius: 10px;
  transition: color .2s, border-color .2s;
}
.ap-pager-btn span { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.ap-pager-btn i { transition: transform .3s var(--ease-out); }
.ap-pager-btn:hover { color: var(--c) !important; border-color: var(--c); }
.ap-pager-btn:hover .bi-arrow-left { transform: translateX(-3px); }
.ap-pager-btn:hover .bi-arrow-right { transform: translateX(3px); }

/* Intro "start here" card */
.ap-intro {
  position: relative;
  background: var(--paper);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: .7rem;
  box-shadow: 0 26px 50px -28px color-mix(in srgb, var(--c) 55%, transparent);
  transform: rotate(1deg);
  transition: transform .5s var(--ease-out);
}
.ap-intro:hover { transform: rotate(0) translateY(-3px); }
.ap-intro-label {
  position: absolute; top: -12px; left: 1.1rem; z-index: 2;
  display: inline-flex; align-items: center; gap: .35rem;
  font-size: .72rem; font-weight: 700; letter-spacing: .04em;
  color: #fff; background: var(--ink);
  padding: .3rem .7rem; border-radius: 50px;
}
.ap-intro-label i { color: #fbbf24; }
.ap-intro-thumb {
  position: relative; display: block;
  aspect-ratio: 16 / 9; border-radius: 14px; overflow: hidden;
  background: var(--c-soft);
}
.ap-intro-thumb img { width: 100%; height: 100%; object-fit: cover; transition: transform .7s var(--ease-out); }
.ap-intro:hover .ap-intro-thumb img { transform: scale(1.05); }
.ap-intro-play {
  position: absolute; left: 50%; top: 50%;
  width: 58px; height: 58px; margin: -29px 0 0 -29px;
  border-radius: 50%;
  display: grid; place-items: center;
  font-size: 1.8rem; color: var(--c);
  background: rgba(255,255,255,.95);
  box-shadow: 0 10px 30px -8px rgba(0,0,0,.35);
  transition: transform .35s var(--ease-out);
}
.ap-intro-play::after {
  content: ''; position: absolute; inset: -6px; border-radius: 50%;
  border: 2px solid rgba(255,255,255,.7);
  animation: apRipple 2.2s ease-out infinite;
}
@keyframes apRipple { from { transform: scale(.9); opacity: 1; } to { transform: scale(1.5); opacity: 0; } }
.ap-intro:hover .ap-intro-play { transform: scale(1.1); }
.ap-intro-body { padding: .9rem .5rem .4rem; }
.ap-intro-body h3 {
  font-family: var(--font-display); font-size: 1.05rem; font-weight: 700; line-height: 1.3;
  margin: 0 0 .2rem;
}
.ap-intro-body h3 a { color: var(--ink) !important; }
.ap-intro-body h3 a:hover { color: var(--c) !important; }
.ap-intro-body p { font-size: .8rem; color: var(--muted); margin: 0 0 .8rem; }
.ap-intro-actions { display: flex; gap: .45rem; }

/* Toolbar */
.ap-toolbar {
  display: flex; align-items: center; justify-content: space-between; gap: .75rem; flex-wrap: wrap;
  padding: .6rem;
  background: var(--paper);
  border: 1px solid var(--border);
  border-radius: 16px;
  box-shadow: var(--shadow-sm);
  margin-bottom: 1rem;
}
.ap-toolbar-filters { display: flex; flex-wrap: wrap; align-items: center; gap: .4rem; flex: 1; min-width: 0; }
.ap-select--sort { margin-left: auto; }
.ap-toolbar-label {
  display: inline-flex; align-items: center; gap: .35rem;
  font-size: .78rem; font-weight: 600; color: var(--muted);
  padding: 0 .4rem;
}
.ap-select, .ap-toggle {
  position: relative;
  display: inline-flex; align-items: center;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  transition: border-color .2s, background .2s, color .2s, box-shadow .2s;
  cursor: pointer;
}
.ap-select > i, .ap-toggle > i { color: var(--muted); font-size: .85rem; transition: color .2s; }
.ap-select > i { position: absolute; left: .7rem; pointer-events: none; }
.ap-select::after {   /* chevron */
  content: '\F282'; font-family: 'bootstrap-icons';
  position: absolute; right: .65rem; font-size: .65rem; color: var(--muted);
  pointer-events: none;
}
.ap-select select {
  appearance: none; -webkit-appearance: none;
  border: 0; outline: 0; background: transparent;
  font: 500 .82rem var(--font-body); color: var(--ink);
  padding: .5rem 1.7rem .5rem 1.95rem;
  cursor: pointer;
  max-width: 190px;
  text-overflow: ellipsis;
}
.ap-select:hover, .ap-toggle:hover { border-color: color-mix(in srgb, var(--c) 45%, transparent); }
.ap-select:focus-within { border-color: var(--c); box-shadow: 0 0 0 3px color-mix(in srgb, var(--c) 15%, transparent); }
.ap-select.is-set, .ap-toggle.is-set {
  background: var(--c-soft);
  border-color: color-mix(in srgb, var(--c) 45%, transparent);
}
.ap-select.is-set > i, .ap-toggle.is-set > i, .ap-select.is-set::after { color: var(--c); }
.ap-select.is-set select { color: var(--c); font-weight: 600; }
.ap-toggle {
  gap: .4rem;
  font-size: .82rem; font-weight: 500; color: var(--ink);
  padding: .5rem .8rem;
  user-select: none;
}
.ap-toggle input { position: absolute; opacity: 0; pointer-events: none; }
.ap-toggle.is-set { color: var(--c); font-weight: 600; }
.ap-toggle:focus-within { box-shadow: 0 0 0 3px color-mix(in srgb, var(--c) 15%, transparent); }
.ap-select--sort { background: var(--paper); }

/* Loading state while the filter form submits */
.ap.is-loading [data-results] { opacity: .45; filter: saturate(.6); transition: opacity .2s, filter .2s; pointer-events: none; }

.ap-results-bar {
  display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: .75rem;
  margin-bottom: 1.25rem;
}
.ap-results-left { display: flex; flex-wrap: wrap; align-items: center; gap: .6rem 1rem; }
.ap-results-count { margin: 0; font-size: .9rem; color: var(--muted); }
.ap-results-count b { color: var(--ink); }
.ap-chips { display: flex; flex-wrap: wrap; align-items: center; gap: .4rem; }
.ap-chip {
  display: inline-flex; align-items: center; gap: .25rem;
  font-size: .78rem; font-weight: 500;
  color: var(--c) !important; background: var(--c-soft);
  padding: .25rem .4rem .25rem .7rem; border-radius: 50px;
  animation: apPop .35s var(--ease-out) both;
  transition: background .2s, color .2s;
}
.ap-chip i { font-size: 1rem; line-height: 1; }
.ap-chip:hover { background: var(--c); color: #fff !important; }
@keyframes apPop { from { transform: scale(.8); opacity: 0; } }
.ap-chip-clear { font-size: .78rem; font-weight: 500; color: var(--muted) !important; margin-left: .25rem; }
.ap-chip-clear:hover { color: var(--ink) !important; text-decoration: underline !important; }

/* Up next */
.ap-next {
  display: flex; align-items: center; justify-content: space-between; gap: 1rem;
  margin-top: 2.5rem;
  padding: 1.2rem 1.4rem;
  border-radius: 18px;
  color: #fff !important;
  background: linear-gradient(120deg, color-mix(in srgb, var(--c) 75%, #000), var(--c));
  box-shadow: 0 20px 40px -24px color-mix(in srgb, var(--c) 80%, transparent);
  transition: transform .35s var(--ease-out), box-shadow .3s;
}
.ap-next small { display: block; font-size: .74rem; opacity: .75; letter-spacing: .04em; margin-bottom: .1rem; }
.ap-next b { font-family: var(--font-display); font-size: 1.2rem; }
.ap-next > i {
  display: grid; place-items: center;
  width: 44px; height: 44px; border-radius: 50%;
  background: rgba(255,255,255,.16); font-size: 1.15rem;
  transition: transform .35s var(--ease-out), background .3s;
}
.ap-next:hover { transform: translateY(-3px); }
.ap-next:hover > i { transform: translateX(4px); background: rgba(255,255,255,.26); }

/* ═════════════════ SEARCH PAGE ═════════════════ */
.ap-hero--search { padding-bottom: clamp(2rem, 4.5vw, 3rem); }
.ap-search-hero { max-width: 760px; }
.ap-search-hero .ap-lede b { color: var(--ink); }
.ap-search--big {
  max-width: 680px;
  padding: .4rem .4rem .4rem 3rem;
  border-radius: 18px;
}
.ap-search--big .ap-search-input { font-size: 1.05rem; padding: .8rem .25rem; }
.ap-search--big .ap-kbd { margin-right: .6rem; }
.ap-search-submit { padding: .8rem 1.25rem; border-radius: 13px; box-shadow: none; }
.ap-search-submit:hover { transform: none; box-shadow: none; filter: brightness(.92); }

/* "Jump to" matching subjects & topics */
.ap-jump { display: flex; align-items: flex-start; gap: .9rem; margin-top: 1.4rem; }
.ap-jump-label {
  flex-shrink: 0; padding-top: .45rem;
  display: inline-flex; align-items: center; gap: .35rem;
  font-size: .72rem; font-weight: 600; letter-spacing: .08em; text-transform: uppercase;
  color: var(--muted);
}
.ap-jump-list { display: flex; flex-wrap: wrap; gap: .45rem; }
.ap-jump-chip {
  display: inline-flex; align-items: center; gap: .45rem;
  font-size: .85rem; font-weight: 500;
  color: var(--ink) !important;
  background: rgba(255,255,255,.88);
  border: 1px solid var(--border);
  padding: .4rem .5rem .4rem .8rem; border-radius: 50px;
  backdrop-filter: blur(6px);
  transition: border-color .2s, transform .25s var(--ease-out), box-shadow .25s;
  animation: apPop .4s var(--ease-out) both;
}
.ap-jump-chip i { color: var(--c); }
.ap-jump-chip small {
  font-size: .7rem; font-weight: 500;
  color: var(--c); background: var(--c-soft);
  padding: .1rem .5rem; border-radius: 50px;
}
.ap-jump-chip:hover {
  border-color: var(--c); transform: translateY(-2px);
  box-shadow: 0 8px 18px -10px color-mix(in srgb, var(--c) 60%, transparent);
}
.ap-jump-chip--section { font-weight: 600; }
.ap-jump-chip.is-empty { color: var(--muted) !important; border-style: dashed; }
.ap-jump-chip.is-empty small { color: var(--muted); background: var(--bg); }

/* Popular topics (empty / no-results state) */
.ap-popular--after { margin-top: 3.5rem; }
.ap-popular-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: .8rem;
}
.ap-pop {
  position: relative; isolation: isolate; overflow: hidden;
  display: flex; align-items: center; gap: .85rem;
  padding: .9rem 1rem;
  background: var(--paper);
  border: 1px solid var(--border);
  border-radius: 14px;
  color: var(--ink) !important;
  transition: transform .35s var(--ease-out), box-shadow .3s, border-color .3s;
}
.ap-pop::before {
  content: ''; position: absolute; inset: 0; z-index: -1;
  background: radial-gradient(200px circle at var(--mx, 50%) var(--my, 50%),
              color-mix(in srgb, var(--c) 11%, transparent), transparent 70%);
  opacity: 0; transition: opacity .3s;
}
.ap-pop:hover {
  transform: translateY(-3px);
  border-color: color-mix(in srgb, var(--c) 40%, transparent);
  box-shadow: 0 14px 30px -20px color-mix(in srgb, var(--c) 60%, transparent);
}
.ap-pop:hover::before { opacity: 1; }
.ap-pop-icon {
  flex-shrink: 0; display: grid; place-items: center;
  width: 40px; height: 40px; border-radius: 12px;
  background: var(--c-soft); color: var(--c); font-size: 1.1rem;
  transition: background .3s, color .3s, transform .4s var(--ease-out);
}
.ap-pop:hover .ap-pop-icon { background: var(--c); color: #fff; transform: rotate(-6deg); }
.ap-pop-main { flex: 1; min-width: 0; display: flex; flex-direction: column; }
.ap-pop-main b { font-family: var(--font-display); font-size: .98rem; }
.ap-pop-main small { font-size: .76rem; color: var(--muted); }
.ap-pop-arrow { color: var(--c); opacity: 0; transform: translateX(-6px); transition: opacity .3s, transform .35s var(--ease-out); }
.ap-pop:hover .ap-pop-arrow { opacity: 1; transform: none; }

/* Highlighted query matches inside result cards */
.ac-card mark {
  background: linear-gradient(transparent 55%, color-mix(in srgb, var(--c) 22%, transparent) 55%);
  color: inherit; padding: 0 .05em; border-radius: 2px;
}

/* ═════════════════ RESPONSIVE ═════════════════ */
@media (max-width: 991.98px) {
  .ap-topic-hero { grid-template-columns: 1fr; gap: 2rem; }
  .ap-intro { max-width: 440px; transform: none; }
}
@media (max-width: 767.98px) {
  .ap-siblings { flex-direction: column; align-items: flex-start; gap: .5rem; }
  .ap-sibling-track { width: 100%; }
  .ap-toolbar { flex-direction: column; align-items: stretch; }
  .ap-toolbar-filters { flex-wrap: nowrap; overflow-x: auto; scrollbar-width: none; padding-bottom: 2px; }
  .ap-toolbar-filters::-webkit-scrollbar { display: none; }
  .ap-select, .ap-toggle { flex-shrink: 0; }
}
@media (max-width: 575.98px) {
  .ap-hero-main { gap: 1rem; }
  .ap-emblem { width: 80px; height: 80px; }
  .ap-emblem-ring--2 { inset: -8px; }
  .ap-emblem-icon { width: 56px; height: 56px; border-radius: 18px; font-size: 1.5rem; }
  .ap-kbd { display: none; }
  .ap-search--big { padding-left: 2.6rem; }
  .ap-search-submit span { display: none; }
  .ap-jump { flex-direction: column; gap: .5rem; }
  .ap-jump-label { padding-top: 0; }
  .ap-topics { grid-template-columns: 1fr; }
  .ap-suggest .ap-btn { width: 100%; }
}

/* Practice lessons on a topic page */
.ap-lesson-cta { margin: 0 0 1.25rem; }
.ap-lesson-cta small { font-weight: 500; opacity: .85; }
.ap-practice-lede { color: var(--muted); margin-top: .35rem; }
.ap-practice-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 1rem; }
.ap-practice-level { background: var(--paper); border: 1px solid var(--border); border-radius: 18px; padding: 1.1rem 1.2rem; }
.ap-practice-name { font-size: .75rem; font-weight: 700; letter-spacing: .06em; text-transform: uppercase; color: var(--c); margin: 0 0 .6rem; }
.ap-practice-level--starter .ap-practice-name { color: #15803d; }
.ap-practice-level--core .ap-practice-name { color: #7c3aed; }
.ap-practice-level--advanced .ap-practice-name { color: #d9480f; }
.ap-practice-level ol { list-style: none; margin: 0; padding: 0; display: grid; gap: .35rem; }
.ap-practice-level a { display: flex; justify-content: space-between; gap: .75rem; padding: .5rem .65rem; border-radius: 10px; color: var(--ink) !important; text-decoration: none; }
.ap-practice-level a:hover { background: var(--c-soft); }
.ap-practice-level small { color: var(--muted); white-space: nowrap; }
.ap-practice-level em { color: var(--muted); font-style: normal; font-size: .8rem; }
.ap-practice-name span { float: right; color: var(--muted); letter-spacing: 0; }
.ap-practice-title { flex: 1; min-width: 0; }
.ap-pbar { display: block; height: 4px; margin-top: .35rem; border-radius: 99px; background: color-mix(in srgb, var(--c) 12%, var(--bg)); overflow: hidden; }
.ap-pbar > span { display: block; height: 100%; border-radius: inherit; background: linear-gradient(90deg, var(--c), #16a34a); }
.ap-pbar--level { height: 8px; margin: 0 0 .8rem; }