/* ==========================================================================
   Public activity library: list, detail and taxonomy landing pages.
   Uses the design tokens from static/css/app.css. Mobile-first.
   ========================================================================== */

.list-plain { list-style: none; padding: 0; margin: 0; }
.chip-count { font-size: var(--fs-xs); font-weight: 700; color: var(--c-text-soft); }
.chip.is-active .chip-count { color: rgba(255, 255, 255, 0.85); }
.chip-domain {
  --chip-color: var(--c-primary);
  background: color-mix(in srgb, var(--chip-color) 12%, var(--c-surface));
  border-color: color-mix(in srgb, var(--chip-color) 35%, var(--c-surface));
  color: color-mix(in srgb, var(--chip-color) 70%, #000);
}
a.chip-domain:hover { border-color: var(--chip-color); color: color-mix(in srgb, var(--chip-color) 80%, #000); }

/* ---------- Activity card (activities/_card.html) ---------- */
.activity-card { --tint: var(--c-primary); display: flex; flex-direction: column; height: 100%; }
.activity-card-media { position: relative; }
.activity-card-media.is-tile {
  background:
    radial-gradient(circle at 25% 20%, rgba(255, 255, 255, 0.7) 0, transparent 45%),
    color-mix(in srgb, var(--tint) 16%, var(--c-surface));
}
.activity-card-icon { font-size: 3.5rem; line-height: 1; filter: drop-shadow(0 4px 6px rgba(45, 42, 50, 0.12)); transition: transform 0.2s ease; }
.activity-card:hover .activity-card-icon { transform: scale(1.08) rotate(-4deg); }
.activity-card-badge { position: absolute; top: var(--s-3); right: var(--s-3); box-shadow: var(--shadow-sm); }
.activity-card-body { display: flex; flex-direction: column; gap: var(--s-2); flex: 1; padding: var(--s-4); }
.activity-card-format { margin: auto 0 0; padding-top: var(--s-2); font-size: var(--fs-sm); font-weight: 700; color: color-mix(in srgb, var(--tint) 65%, var(--c-text)); }
.activity-grid { grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); }

/* ---------- Page heroes ---------- */
.library-hero, .landing-hero {
  --tint: var(--c-primary);
  padding: var(--s-5) 0 var(--s-5);
  margin-bottom: var(--s-5);
  background:
    radial-gradient(circle at 8% 10%, var(--c-sun-50) 0, transparent 40%),
    radial-gradient(circle at 92% 0%, color-mix(in srgb, var(--tint) 12%, transparent) 0, transparent 45%),
    var(--c-bg);
  border-bottom: 1px solid var(--c-border);
}
.library-hero h1 { margin-bottom: var(--s-2); }
.landing-hero-body { display: flex; gap: var(--s-4); align-items: flex-start; }
.landing-icon {
  flex: none; width: 3.5rem; height: 3.5rem; border-radius: var(--radius); display: grid; place-items: center;
  font-size: 2rem; background: color-mix(in srgb, var(--tint) 14%, var(--c-surface)); transform: rotate(-4deg);
}
.landing-intro { max-width: 70ch; color: var(--c-text-muted); font-size: var(--fs-lg); }
.landing-intro p:last-child { margin-bottom: 0; }

/* ---------- Library (list page) ---------- */
.library-layout { display: grid; gap: var(--s-5); }
.library-filters-toggle { display: none; }
.library-filters-panel {
  background: var(--c-surface); border: 1px solid var(--c-border); border-radius: var(--radius);
  padding: var(--s-4); display: grid; gap: var(--s-4);
}
.library-filters-head { gap: var(--s-2); }
.library-filters-title { font-size: var(--fs-lg); margin: 0; }
.filter-group { border: 0; padding: 0; margin: 0; min-width: 0; }
.filter-legend { display: block; padding: 0; margin-bottom: var(--s-2); font-weight: 800; font-size: var(--fs-sm); color: var(--c-text); }

.filter-chips { display: flex; flex-wrap: wrap; gap: var(--s-1); }
.filter-chip { position: relative; cursor: pointer; }
.filter-chip input, .facet input { position: absolute; opacity: 0; width: 1px; height: 1px; pointer-events: none; }
.filter-chip > span {
  display: inline-flex; align-items: center; gap: 0.3rem; min-width: 2.4rem; justify-content: center;
  padding: 0.3rem 0.7rem; border-radius: var(--radius-pill); border: 2px solid var(--c-border);
  background: var(--c-surface); font-weight: 700; font-size: var(--fs-sm); transition: border-color 0.15s, background 0.15s;
}
.filter-chip:hover > span { border-color: var(--c-border-strong); }
.filter-chip input:checked + span { background: var(--c-primary); border-color: var(--c-primary); color: #fff; }
.filter-chip input:checked + span .facet-count { color: rgba(255, 255, 255, 0.85); }
.filter-chip input:focus-visible + span, .facet input:focus-visible + .facet-label { box-shadow: var(--focus); }
.filter-chip.is-empty > span { opacity: 0.5; }

.facet-list { display: grid; gap: 2px; }
.facet {
  --dot: var(--c-border-strong);
  position: relative; display: flex; align-items: center; justify-content: space-between; gap: var(--s-2);
  padding: 0.4rem 0.6rem; border-radius: var(--radius-sm); cursor: pointer; font-size: var(--fs-sm);
}
.facet:hover { background: var(--c-surface-2); }
.facet-label { display: inline-flex; align-items: center; gap: var(--s-2); border-radius: var(--radius-sm); min-width: 0; }
.facet-label::before {
  content: ""; flex: none; width: 0.65rem; height: 0.65rem; border-radius: 50%;
  border: 2px solid var(--dot); background: var(--c-surface);
}
.facet input:checked + .facet-label { font-weight: 800; color: var(--c-primary-600); }
.facet input:checked + .facet-label::before { border-color: var(--c-primary); background: var(--c-primary); box-shadow: inset 0 0 0 2px var(--c-surface); }
.facet:has(input:checked) { background: var(--c-primary-50); }
.facet-icon { width: 1.25rem; text-align: center; }
.facet-count { font-size: var(--fs-xs); font-weight: 700; color: var(--c-text-soft); }

.library-results { min-width: 0; }
.library-search { margin-bottom: var(--s-4); }
.library-search .input { min-width: 0; }
.library-summary { margin-bottom: var(--s-3); align-items: flex-end; }
.library-heading { font-size: var(--fs-xl); margin: 0; }
.library-sort { display: flex; align-items: center; gap: var(--s-2); }
.library-sort .select { width: auto; padding-block: 0.4rem; }
.library-active { margin-bottom: var(--s-4); }
.library-grid { grid-template-columns: 1fr; grid-auto-flow: row dense; gap: var(--s-4); }
.library-grid-ad { grid-column: 1 / -1; }
.library-grid-ad .ad-slot { margin: 0; }
.library-empty h3 { margin-bottom: var(--s-2); }

@media (min-width: 520px) {
  .library-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 960px) {
  .library-filters-toggle { display: inline-flex; }
  .library-filters.is-collapsed .library-filters-panel { display: none; }
  .library-filters:not(.is-collapsed) .library-filters-panel { margin-top: var(--s-3); }
}
@media (min-width: 961px) {
  .library-layout { grid-template-columns: 260px minmax(0, 1fr); gap: var(--s-6); align-items: start; }
  .library-filters { position: sticky; top: calc(var(--header-h) + var(--s-4)); max-height: calc(100vh - var(--header-h) - var(--s-6)); overflow-y: auto; border-radius: var(--radius); }
  .library-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}

/* ---------- Detail page ---------- */
.staff-bar { background: var(--c-info-50); border-bottom: 1px solid #bcdcf7; padding: var(--s-2) 0; }
.shared-banner { background: var(--c-sky-50); border-bottom: 1px solid #bfe0f4; padding: var(--s-3) 0; color: #1d6596; font-weight: 600; }
.shared-banner.is-private { background: var(--c-sun-50); border-color: #ffe39a; color: #7a5600; }

.detail-hero {
  --tint: var(--c-primary);
  padding: var(--s-5) 0 var(--s-6);
  margin-bottom: var(--s-6);
  background:
    radial-gradient(circle at 0% 0%, color-mix(in srgb, var(--tint) 14%, transparent) 0, transparent 50%),
    radial-gradient(circle at 100% 100%, var(--c-sun-50) 0, transparent 45%),
    var(--c-bg);
  border-bottom: 1px solid var(--c-border);
}
.detail-hero-body { max-width: 860px; }
.detail-title { font-size: var(--fs-4xl); }
.detail-subtitle { margin-top: calc(var(--s-2) * -1); font-family: var(--font-display); font-size: var(--fs-xl); font-weight: 600; color: var(--c-text-muted); }
.detail-taxonomy { display: grid; gap: var(--s-2); }
.detail-taxonomy-label { font-family: var(--font-body); font-size: var(--fs-xs); text-transform: uppercase; letter-spacing: 0.06em; font-weight: 800; color: var(--c-text-muted); margin: 0; }

.detail-layout { gap: var(--s-6); }
.detail-main { min-width: 0; display: grid; gap: var(--s-6); align-content: start; }
.detail-main > .ad-slot { margin: 0 auto; width: 100%; }
.detail-cover { margin: 0; border-radius: var(--radius-lg); overflow: hidden; border: 1px solid var(--c-border); background: var(--c-surface-2); box-shadow: var(--shadow-sm); }
.detail-cover img { width: 100%; height: auto; max-height: 560px; object-fit: cover; }
.detail-section h2 { font-size: var(--fs-xl); display: flex; align-items: center; gap: var(--s-2); }
.detail-section > .row-between h2 { margin-bottom: 0; }
.detail-section > .row-between { margin-bottom: var(--s-3); }
.detail-safety { align-items: flex-start; }
.detail-safety-title { font-family: var(--font-body); font-size: var(--fs-md); font-weight: 800; margin: 0 0 var(--s-1); }
.detail-safety p:last-child { margin-bottom: 0; }

.steps { list-style: none; padding: 0; margin: 0; counter-reset: step; display: grid; gap: var(--s-3); }
.steps li { counter-increment: step; position: relative; padding: var(--s-3) var(--s-4) var(--s-3) 3.5rem; background: var(--c-surface); border: 1px solid var(--c-border); border-radius: var(--radius); }
.steps li::before {
  content: counter(step); position: absolute; left: var(--s-3); top: var(--s-3);
  width: 2rem; height: 2rem; border-radius: 50%; display: grid; place-items: center;
  font-family: var(--font-display); font-weight: 700; background: var(--c-primary); color: #fff;
}
.materials-list { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: var(--s-2); list-style: none; padding: 0; margin: 0; }
.materials-list li { padding: var(--s-2) var(--s-3); background: var(--c-surface-2); border-radius: var(--radius-sm); }
.materials-list li::before { content: "▢"; margin-right: var(--s-2); color: var(--c-text-soft); }
.tips-list, .talk-list { list-style: none; padding: 0; margin: 0; display: grid; gap: var(--s-2); }
.tips-list li, .talk-list li { position: relative; padding-left: 1.9rem; }
.tips-list li::before { content: "★"; position: absolute; left: 0.3rem; color: var(--c-sun); font-size: 1.1rem; line-height: 1.4; }
.talk-list li::before { content: "?"; position: absolute; left: 0; top: 0.1rem; width: 1.35rem; height: 1.35rem; border-radius: 50%; display: grid; place-items: center; font-weight: 800; font-size: 0.8rem; background: var(--c-sky-50); color: #1d6596; }

.variation-grid { display: grid; gap: var(--s-3); grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }
.variation { padding: var(--s-4); border-radius: var(--radius); border: 1px solid var(--c-border); background: var(--c-surface); }
.variation-label { font-size: var(--fs-md); font-family: var(--font-display); margin-bottom: var(--s-2); }
.variation-easier { background: var(--c-mint-50); border-color: #b5ebe5; }
.variation-harder { background: var(--c-coral-50); border-color: #ffc9c9; }
.variation-extension { background: var(--c-sky-50); border-color: #bfe0f4; }

.worksheet-preview { background: var(--c-surface); border: 1px solid var(--c-border); border-radius: var(--radius); padding: var(--s-4); overflow-x: auto; }
.worksheet-pages { display: grid; gap: var(--s-4); background: var(--c-surface); border: 1px solid var(--c-border); border-radius: var(--radius); padding: var(--s-4); }
.worksheet-page-image { display: block; width: 100%; max-width: 816px; height: auto; margin: 0 auto; border: 1px solid var(--c-border); border-radius: var(--radius-sm); box-shadow: var(--shadow-sm, 0 1px 3px rgba(0,0,0,.08)); }
.worksheet-locked-wrap { position: relative; border-radius: var(--radius); overflow: hidden; }
.worksheet-locked { max-height: 420px; overflow: hidden; filter: blur(5px) saturate(0.8); user-select: none; pointer-events: none; }
.worksheet-lock {
  position: absolute; inset: 0; display: grid; place-content: center; justify-items: center; gap: var(--s-2);
  padding: var(--s-5); background: linear-gradient(180deg, rgba(255, 251, 245, 0.35), rgba(255, 251, 245, 0.92) 60%);
  text-align: center;
}
.worksheet-lock-icon { font-size: 2.5rem; margin: 0; }
.worksheet-lock .upsell { max-width: 420px; box-shadow: var(--shadow); }

.detail-aside { display: grid; grid-template-rows: 1fr auto; gap: var(--s-5); align-self: stretch; min-width: 0; }
.detail-aside-sticky { min-height: 0; min-width: 0; }
.detail-layout > * { min-width: 0; }
.glance-title { font-size: var(--fs-xl); margin: 0; }
.glance-subtitle { font-family: var(--font-body); font-size: var(--fs-sm); font-weight: 800; margin-bottom: var(--s-2); }
.glance-facts { display: grid; grid-template-columns: 1fr 1fr; gap: var(--s-3); margin: 0; }
.glance-facts div { background: var(--c-surface-2); border-radius: var(--radius-sm); padding: var(--s-2) var(--s-3); }
.glance-facts dt { font-size: var(--fs-xs); font-weight: 700; color: var(--c-text-muted); text-transform: uppercase; letter-spacing: 0.04em; }
.glance-facts dd { margin: 0; font-weight: 700; }
.glance-materials { margin: 0; padding-left: 1.1rem; font-size: var(--fs-sm); }
.glance-locked { color: var(--c-text-muted); }
.glance-studio { padding-top: var(--s-4); border-top: 1px dashed var(--c-border); }
.detail-related { margin-top: var(--s-6); background: var(--c-surface-2); }

@media (min-width: 961px) {
  .detail-aside-sticky .glance {
    position: sticky; top: calc(var(--header-h) + var(--s-4));
    max-height: calc(100vh - var(--header-h) - var(--s-6)); overflow-y: auto;
  }
}
@media (max-width: 640px) {
  .detail-title { font-size: var(--fs-2xl); }
  .glance-facts { grid-template-columns: 1fr; }
  .steps li { padding-left: 3.1rem; }
}

/* ---------- Landing & taxonomy index pages ---------- */
.landing-layout { gap: var(--s-6); }
.landing-related { min-width: 0; }
.related-group { display: grid; grid-template-columns: minmax(0, 1fr); gap: var(--s-2); min-width: 0; }
.related-group li, .related-group a { max-width: 100%; white-space: normal; overflow-wrap: anywhere; }
.related-title { font-family: var(--font-body); font-size: var(--fs-sm); font-weight: 800; text-transform: uppercase; letter-spacing: 0.05em; color: var(--c-text-muted); margin: 0; }
.taxonomy-card { --tint: var(--c-primary); position: relative; border-top: 4px solid color-mix(in srgb, var(--tint) 70%, var(--c-surface)); transition: transform 0.12s ease, box-shadow 0.15s ease; }
.taxonomy-card:hover { transform: translateY(-2px); box-shadow: var(--shadow); }
.taxonomy-icon { background: color-mix(in srgb, var(--tint) 14%, var(--c-surface)); }
.taxonomy-card .card-title a { color: var(--c-text); text-decoration: none; }
.stretched-link::after { content: ""; position: absolute; inset: 0; border-radius: var(--radius); }
.stretched-link:focus-visible { box-shadow: none; }
.stretched-link:focus-visible::after { box-shadow: var(--focus); }
.taxonomy-children { position: relative; z-index: 1; }
.taxonomy-page { margin-bottom: var(--s-6); }

@media (max-width: 640px) {
  .landing-hero-body { flex-direction: column; gap: var(--s-3); }
  .landing-intro { font-size: var(--fs-md); }
}

@media print {
  .library-filters, .library-search, .library-sort, .detail-aside, .detail-related, .staff-bar, .worksheet-lock { display: none !important; }
  .detail-layout { display: block; }
}

/* Design illustrations ({% design_art %}) in page headers and index tiles. */
.landing-icon .design-art { width: 80%; height: 80%; }
.taxonomy-icon { width: 4rem; height: 4rem; }
.activity-card-format .design-art { width: 1.5em; height: 1.5em; }
.landing-icon:has(.design-art) { width: 4.75rem; height: 4.75rem; }