/* =====================================================================
   Learn Article List Page (`.learn-page`) — style-overhaul, main.css-free
   ---------------------------------------------------------------------
   Refactor of the legacy Bootstrap-based learn article list page. Keeps
   the canonical article DOM (link-card > image + content: category →
   title → excerpt → CTA), applies the global --o-* design-system
   visual language (borderless white card, --o-radius-sm, --o-shadow,
   editorial rhythm) to achieve cross-page visual unity.

   LOAD ORDER (in master @yield('css')):
     {{ asset('assets/css/breadcrumb.css') }}
     {{ asset('assets/css/product-list.css') }}
     {{ asset('assets/css/learn.css') }}

   ZERO Bootstrap classes. ZERO legacy class names (.single-blog,
   .blog-img, .blog-content, etc. are retired). All rules scoped under
   .learn-page so there is zero bleed.
   ===================================================================== */

/* ---------- page root + container geometry (DESIGN_SPEC §2-8 / §2-9) ---------- */
.learn-page {
  background: var(--o-bg);
  font-family: var(--o-font-body);
  color: var(--o-ink);
  min-height: 100vh;
}
.learn-page__inner {
  box-sizing: content-box;
  margin: 0 auto;
  padding: 36px 10px 48px;
  max-width: 1180px;
}
@media (min-width: 1300px) { .learn-page__inner { max-width: 1280px; } }
@media (min-width: 1400px) { .learn-page__inner { max-width: 1380px; } }

/* ---------- page layout: main column + desktop sidebar ---------- */
.learn-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 24px;
}
@media (min-width: 992px) {
  .learn-grid {
    grid-template-columns: minmax(0, 1fr) 320px;
    gap: 32px;
  }
}

/* ---------- article grid ---------- */
.learn-cards {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
}
@media (min-width: 768px) {
  .learn-cards {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 20px;
  }
}

/* ---------- article card ---------- */
.learn-card {
  display: flex;
  flex-direction: column;
  background: var(--o-card);
  border: none;
  border-radius: var(--o-radius-sm);
  box-shadow: var(--o-shadow);
  overflow: hidden;
  transition: transform .25s ease, box-shadow .25s ease;
  will-change: transform;
}
.learn-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--o-shadow-hover);
}
.learn-card:active {
  transform: scale(.98);
}

/* image area (fills card width, fixed aspect to match legacy ~2.4:1) */
.learn-card__img {
  display: block;
  width: 100%;
  overflow: hidden;
  aspect-ratio: 400 / 230;
  background: var(--o-line-soft);
}
.learn-card__img img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform .45s ease;
}
.learn-card:hover .learn-card__img img {
  transform: scale(1.06);
}

/* textual body */
.learn-card__content {
  padding: 16px 18px 18px;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 8px;
}
.learn-card__category {
  display: inline-block;
  font-size: 12px;
  font-weight: 600;
  color: var(--o-accent);
  letter-spacing: .02em;
  text-transform: uppercase;
}
.learn-card__category:hover {
  color: var(--o-accent-ink);
}
.learn-card__title {
  margin: 0;
  line-height: 1.3;
}
.learn-card__title a {
  font-size: 17px;
  font-weight: 700;
  color: var(--o-ink);
  text-decoration: none;
}
.learn-card__title a:hover {
  color: var(--o-accent);
}
.learn-card__excerpt {
  margin: 4px 0 0;
  font-size: 13px;
  line-height: 1.5;
  color: var(--o-ink-2);
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.learn-card__cta {
  margin-top: auto;
  padding-top: 4px;
}
.learn-card__cta-link {
  display: inline-block;
  font-size: 13px;
  font-weight: 600;
  color: var(--o-accent);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color .2s ease;
}
.learn-card__cta-link:hover {
  border-bottom-color: var(--o-accent);
}

/* ---------- sidebar widgets (popular feeds / categories / tags) ---------- */
.learn-aside {
  display: flex;
  flex-direction: column;
  gap: 20px;
}
.learn-widget {
  background: var(--o-card);
  border: none;
  border-radius: var(--o-radius-sm);
  box-shadow: var(--o-shadow);
  padding: 20px;
}
.learn-widget__title {
  margin: 0 0 14px;
  font-size: 15px;
  font-weight: 700;
  color: var(--o-ink);
}

/* popular feeds: list of left-thumb + title + date items */
.learn-feed-item {
  display: flex;
  gap: 12px;
  align-items: center;
  padding: 12px 0;
  border-bottom: 1px solid var(--o-line);
}
.learn-feed-item:first-child { padding-top: 0; }
.learn-feed-item:last-child {
  border-bottom: none;
  padding-bottom: 0;
}
.learn-feed-item__img {
  display: block;
  flex: 0 0 80px;
  width: 80px;
  height: 58px;
  border-radius: var(--o-radius-tag);
  overflow: hidden;
}
.learn-feed-item__img img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.learn-feed-item__title {
  margin: 0 0 4px;
  font-size: 13px;
  line-height: 1.4;
}
.learn-feed-item__title a {
  color: var(--o-ink);
  text-decoration: none;
}
.learn-feed-item__title a:hover {
  color: var(--o-accent);
}
.learn-feed-item__meta {
  font-size: 12px;
  color: var(--o-ink-3);
}

/* categories */
.learn-category {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 0;
  border-bottom: 1px solid var(--o-line);
}
.learn-category:last-child {
  border-bottom: none;
  padding-bottom: 0;
}
.learn-category:first-child { padding-top: 0; }
.learn-category a {
  font-size: 13px;
  font-weight: 500;
  color: var(--o-ink-2);
  text-decoration: none;
}
.learn-category a:hover {
  color: var(--o-accent);
}

/* tags */
.learn-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.learn-tags a {
  display: inline-block;
  padding: 6px 12px;
  font-size: 12px;
  font-weight: 500;
  color: var(--o-ink-2);
  background: var(--o-line-soft);
  border-radius: var(--o-radius-tag);
  text-decoration: none;
  transition: background-color .2s ease, color .2s ease;
}
.learn-tags a:hover {
  background: var(--o-accent);
  color: #fff;
}

/* ---------- 选中态：分类 / 标签被激活时高亮（与顶部药丸、URL 状态保持一致） ---------- */
.learn-category a.is-active {
  color: var(--o-accent);
  font-weight: 600;
}
.learn-tags a.is-active {
  background: var(--o-accent);
  color: #fff;
}
.learn-nav-item.is-active {
  color: var(--o-accent);
  font-weight: 600;
}
.learn-nav-tag.is-active {
  background: var(--o-accent);
  color: #fff;
}

/* ---------- active filters: selected category/tag pills (above cards) ---------- */
/* 两端均显示（移动端也是核心场景）；水平齐平（容器 flex row + center），
   垂直居中（药丸内 align-items:center + line-height:1，复刻 pl-search-chip 范式）。 */
.learn-active-filters {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin-bottom: 12px;
}
.learn-active-filter {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  height: 32px;
  padding: 0 6px 0 12px;
  background: var(--o-card);
  border: none;
  border-radius: 999px;
  font: 500 13px var(--o-font-display);
  color: var(--o-ink-2);
  box-shadow: var(--o-shadow);
}
.learn-active-filter__label,
.learn-active-filter__value {
  line-height: 1;
}
.learn-active-filter__label {
  color: var(--o-ink-3);
  white-space: nowrap;
}
.learn-active-filter__value {
  color: var(--o-ink-2);
  font-weight: 600;
  white-space: nowrap;
}
.learn-active-filter__clear {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 22px;
  height: 22px;
  margin-left: 2px;
  border: none;
  border-radius: 50%;
  background: transparent;
  color: var(--o-ink-3);
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
  transition: background-color .15s ease, color .15s ease;
}
.learn-active-filter__clear:hover {
  background: var(--o-accent-soft);
  color: var(--o-accent);
}
.learn-active-filter__clear:active {
  transform: scale(.92);
}
.learn-active-filter__clear svg {
  width: 14px;
  height: 14px;
}

/* ---------- desktop pager (DESIGN_SPEC §6.6) ---------- */
.learn-pager {
  display: flex;
  justify-content: center;
  margin-top: 32px;
}
.learn-pager ul {
  display: flex;
  align-items: center;
  gap: 6px;
  list-style: none;
  margin: 0;
  padding: 0;
}
.learn-pager li {
  display: flex;
  align-items: center;
}
.learn-pager a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 36px;
  height: 36px;
  padding: 0 10px;
  border-radius: var(--o-radius-tag);
  border: 1px solid var(--o-line);
  background: var(--o-card);
  color: var(--o-ink);
  font-size: 13px;
  font-weight: 500;
  text-decoration: none;
  transition: color .15s ease, border-color .15s ease, background-color .15s ease;
}
.learn-pager a:hover {
  border-color: var(--o-accent);
  color: var(--o-accent);
}
.learn-pager li.active a {
  background: var(--o-accent);
  border-color: var(--o-accent);
  color: #fff;
}
.learn-pager li.learn-pager__ellipsis {
  color: var(--o-ink-3);
  font-size: 14px;
  padding: 0 4px;
}

/* ---------- empty state ---------- */
.learn-empty {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  min-height: 300px;
  background: var(--o-card);
  border-radius: var(--o-radius-sm);
  box-shadow: var(--o-shadow);
  padding: 32px;
  grid-column: 1 / -1;
}
.learn-empty h3 {
  font: 600 18px var(--o-font-display);
  color: var(--o-ink-2);
  margin: 0;
}

/* ---------- mobile-only rules (≤991px) ---------- */
@media (max-width: 991px) {
  /* §2-9 / §6.15: match .ac-layout baseline 14px gutters */
  .learn-page__inner {
    padding: 14px 14px calc(var(--o-bottomnav-h) + 20px);
  }
  /* sidebar hides on mobile */
  .learn-aside {
    display: none;
  }

  /* 移动端：分类 & 标签 抽屉（方案 B，对齐产品列表 cr-filter-drawer 母题）
     用 --cr-* 移动端体系、z-index 1100/1101、底部 bottom-sheet、slide-up 0.3s，
     与全站 filter 抽屉视觉/层级一致。数据由服务端 $topCategoryList/$tags 直渲，无需 JS 填充。 */
  .learn-nav-bar {
    padding: 0 0 10px;
  }
  .learn-nav-trigger {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    width: 100%;
    height: 44px;
    background: var(--cr-mobile-card);
    border: 1px solid var(--cr-mobile-line);
    border-radius: var(--cr-radius-btn);
    font-family: var(--cr-font-display);
    font-weight: 600;
    font-size: 14px;
    color: var(--cr-mobile-ink);
    box-shadow: var(--cr-shadow-card);
    min-height: 44px;
    text-transform: none;
  }
  .learn-nav-trigger svg {
    width: 18px;
    height: 18px;
  }
  .learn-nav-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: calc(var(--cr-bottomnav-h) + env(safe-area-inset-bottom));
    background: rgba(13, 17, 23, 0.5);
    z-index: 1100;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.25s ease, visibility 0.25s ease;
  }
  .learn-nav-overlay.cr-open {
    opacity: 1;
    visibility: visible;
  }
  .learn-nav-drawer {
    position: fixed;
    left: 0;
    right: 0;
    bottom: calc(var(--cr-bottomnav-h) + env(safe-area-inset-bottom));
    z-index: 1101;
    background: #ffffff;
    border-radius: 14px 14px 0 0;
    box-shadow: 0 -4px 20px rgba(13, 17, 23, 0.15);
    transform: translateY(calc(100% + var(--cr-bottomnav-h) + env(safe-area-inset-bottom)));
    transition: transform 0.3s cubic-bezier(0.22, 0.61, 0.36, 1);
    max-height: 70%;
    display: flex;
    flex-direction: column;
    padding-bottom: env(safe-area-inset-bottom);
  }
  .learn-nav-drawer.cr-open {
    transform: translateY(0);
  }
  .learn-nav-handle {
    width: 36px;
    height: 4px;
    background: #d1d5db;
    border-radius: 2px;
    margin: 8px auto 4px;
    flex: 0 0 auto;
  }
  .learn-nav-title {
    flex: 0 0 auto;
    font-family: var(--cr-font-display);
    font-size: 16px;
    font-weight: 700;
    color: #000000;
    padding: 10px 14px 4px;
    margin: 0;
    text-transform: none;
    letter-spacing: 0.01em;
  }
  .learn-nav-content {
    flex: 1 1 auto;
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
    overscroll-behavior: contain;
    padding: 8px 14px;
  }
  .learn-nav-group-title {
    position: sticky;
    top: -8px;
    background: #ffffff;
    z-index: 2;
    font-family: var(--cr-font-display);
    font-size: 11px;
    font-weight: 700;
    color: #6b7280;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    padding: 8px 0;
    margin: 0;
  }
  .learn-nav-list {
    display: flex;
    flex-direction: column;
  }
  .learn-nav-item {
    display: flex;
    align-items: center;
    min-height: 44px;
    padding: 8px 4px;
    font-size: 14px;
    color: #111827;
    text-decoration: none;
    border-bottom: 1px solid #e5e7eb;
  }
  .learn-nav-item:last-child {
    border-bottom: none;
  }
  .learn-nav-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    padding: 4px 0 8px;
  }
  .learn-nav-tag {
    display: inline-block;
    padding: 6px 12px;
    font-size: 12px;
    font-weight: 500;
    color: #374151;
    background: #f3f4f6;
    border-radius: 999px;
    text-decoration: none;
  }
  .learn-card:hover {
    transform: none;
  }
  .learn-cards {
    gap: 14px;
  }
  .learn-card__excerpt {
    -webkit-line-clamp: 2;
  }
}

/* ---------- reduced motion ---------- */
@media (prefers-reduced-motion: reduce) {
  .learn-card,
  .learn-card__img img {
    transition: none;
  }
  .learn-card:hover {
    transform: none;
  }
  .learn-card:active {
    transform: none;
  }
  .learn-card:hover .learn-card__img img {
    transform: none;
  }
}

/* =====================================================================
   Reusable mobile widgets are inherited from product-list.css:
     .cr-load-more / .cr-loading / .cr-spinner / .cr-no-more
     .cr-desktop-only
   ===================================================================== */