/**
 * GoTooi 專題／分類頁 — page-specific (shell/sidebar/topbar/cards in layout.css)
 */

/* Banner */
.topic-banner {
  position: relative;
  margin: 1rem 0 1.25rem;
  border-radius: var(--card-radius);
  overflow: hidden;
  min-height: 220px;
  background: linear-gradient(135deg, var(--color-teal) 0%, var(--color-teal-dark) 55%, var(--color-brand-navy) 100%);
}

.topic-banner--empty {
  min-height: auto;
  padding: 2.5rem 1.5rem;
  color: #fff;
  text-align: center;
}

.topic-banner--simple {
  min-height: auto;
  padding: 1.75rem 1.5rem;
  color: #fff;
}

.topic-banner--simple .topic-banner-inner {
  max-width: var(--container-max, 1120px);
  margin: 0 auto;
}

.topic-banner--simple .topic-banner-stats {
  margin-top: 0.75rem;
}

.topic-banner-cover {
  position: absolute;
  inset: 0;
}

.topic-banner-cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.topic-banner-cover--placeholder {
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  opacity: 0.3;
}

.topic-banner-overlay {
  position: relative;
  z-index: 1;
  min-height: 220px;
  display: flex;
  align-items: flex-end;
  padding: 1.75rem 1.5rem;
  background: linear-gradient(to top, rgb(0 0 0 / 68%) 0%, rgb(0 0 0 / 18%) 55%, transparent 100%);
  color: #fff;
}

@media (min-width: 769px) {
  .topic-banner { min-height: 280px; }
  .topic-banner-overlay { min-height: 280px; padding: 2.25rem 2rem; }
}

.topic-banner-eyebrow {
  margin: 0 0 0.35rem;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  opacity: 0.88;
}

.topic-banner-title {
  margin: 0 0 0.5rem;
  font-size: clamp(1.65rem, 4.5vw, 2.35rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.15;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.topic-banner-subtitle {
  margin: 0 0 0.35rem;
  font-size: 1.02rem;
  font-weight: 600;
  opacity: 0.95;
}

.topic-banner-desc {
  margin: 0.5rem 0 0;
  font-size: 0.95rem;
  line-height: 1.5;
  opacity: 0.92;
}

.topic-banner-desc:empty {
  display: none;
}

.topic-banner-stats {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem 1.25rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.topic-banner-stat {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.88rem;
  font-weight: 600;
  opacity: 0.95;
}

/* Filter tabs */
.topic-filters {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  margin-bottom: 1.25rem;
}

.topic-filters-scroll {
  flex: 1;
  min-width: 0;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
}

.topic-filters-scroll::-webkit-scrollbar { display: none; }

.topic-filter-pills {
  display: flex;
  flex-wrap: nowrap;
  gap: 0.45rem;
  padding-bottom: 0.15rem;
}

@media (min-width: 1025px) {
  .topic-filter-pills { flex-wrap: wrap; }
}

.topic-filter-pill {
  flex-shrink: 0;
  padding: 0.5rem 1rem;
  border-radius: var(--radius-pill);
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  color: var(--color-text-muted);
  font-family: inherit;
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  white-space: nowrap;
}

.topic-filter-pill:hover {
  transform: translateY(-1px);
  background: var(--color-teal-muted);
  color: var(--color-teal-dark);
}

.topic-filter-icon-btn {
  flex-shrink: 0;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  color: var(--color-text-muted);
  cursor: pointer;
}

.topic-filter-icon-btn:hover {
  background: var(--color-teal-muted);
  color: var(--color-teal-dark);
}

/* Article grid */
.topic-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
}

@media (min-width: 769px) {
  .topic-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1.15rem;
  }
}

@media (min-width: 1025px) {
  .topic-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: var(--grid-gap);
  }
}

@media (min-width: 1280px) {
  .topic-page .topic-main,
  .topic-shell .topic-main {
    max-width: 1180px;
  }

  .topic-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 1.35rem;
  }

  .topic-hero,
  .topic-hero-overlay {
    min-height: 420px;
  }

  .topic-hero-title {
    font-size: clamp(2.1rem, 3.5vw, 2.75rem);
  }

  .topic-filter-pills {
    gap: 0.55rem;
  }
}

/* Card meta (base card in layout.css) */
.topic-grid > .post-card {
  height: 100%;
}

.post-card--skeleton {
  pointer-events: none;
}

.topic-article-card { height: 100%; }

.topic-article-card-cover-ph {
  display: grid;
  place-items: center;
  width: 100%;
  height: 100%;
  color: var(--color-primary);
  opacity: 0.45;
}

.topic-article-card-body {
  display: flex;
  flex-direction: column;
  flex: 1;
  gap: 0.65rem;
}

.topic-article-card-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  margin-top: auto;
  font-size: 0.78rem;
  color: var(--color-text-muted);
}

.topic-article-card-author {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  min-width: 0;
  font-weight: 600;
}

.topic-article-card-author span {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.topic-article-card-avatar {
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: var(--color-teal-light);
  display: grid;
  place-items: center;
  font-size: 0.65rem;
  font-weight: 700;
  color: var(--color-teal-dark);
  flex-shrink: 0;
  overflow: hidden;
}

.topic-article-card-avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.topic-article-card-stats {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  flex-shrink: 0;
}

.topic-article-card-stat {
  display: inline-flex;
  align-items: center;
  gap: 0.2rem;
}

/* Skeleton */
.topic-article-card--skeleton { pointer-events: none; }

.topic-skeleton-cover {
  aspect-ratio: 4 / 3;
  background: linear-gradient(90deg, var(--color-border) 25%, rgb(91 127 255 / 8%) 50%, var(--color-border) 75%);
  background-size: 200% 100%;
  animation: topic-shimmer 1.4s infinite;
}

.topic-skeleton-line {
  height: 12px;
  margin: 0.85rem 0.95rem 0;
  border-radius: 6px;
  background: linear-gradient(90deg, var(--color-border) 25%, rgb(91 127 255 / 8%) 50%, var(--color-border) 75%);
  background-size: 200% 100%;
  animation: topic-shimmer 1.4s infinite;
}

.topic-skeleton-line.short {
  width: 55%;
  margin-bottom: 1rem;
}

@keyframes topic-shimmer {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

.topic-empty {
  grid-column: 1 / -1;
  padding: 2.5rem 1rem;
  text-align: center;
  color: var(--color-text-muted);
}

.topic-load-more {
  display: flex;
  justify-content: center;
  margin-top: 1.75rem;
}

/* Breadcrumb */
.topic-breadcrumb-wrap {
  margin: 0.85rem 0 0.35rem;
}

.topic-breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.35rem 0.5rem;
  font-size: 0.82rem;
  color: var(--color-text-muted);
}

.topic-breadcrumb a {
  color: var(--color-primary);
  text-decoration: none;
  font-weight: 600;
}

.topic-breadcrumb a:hover { text-decoration: underline; }

.topic-breadcrumb-sep {
  opacity: 0.55;
  user-select: none;
}

.topic-breadcrumb [aria-current="page"] {
  color: var(--color-text);
  font-weight: 700;
}

/* Sub-topic nav */
.topic-subtopics {
  margin: 0 0 1.15rem;
  padding: 1rem 1.1rem;
  border-radius: var(--card-radius);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
}

.topic-subtopics-toggle {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  width: 100%;
  margin: 0 0 0.75rem;
  padding: 0;
  border: none;
  background: none;
  font-family: inherit;
  font-size: 0.92rem;
  font-weight: 700;
  color: var(--color-text);
  text-align: left;
  cursor: pointer;
}

.topic-subtopics-toggle-label {
  flex: 1;
  min-width: 0;
}

.topic-subtopics-chevron {
  flex-shrink: 0;
  font-size: 0.65rem;
  color: var(--color-text-muted);
  transition: transform 0.2s ease;
}

.topic-subtopics-body {
  overflow: hidden;
  transition: max-height 0.28s ease, opacity 0.22s ease;
}

.topic-subtopics-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
}

@media (max-width: 1024px) {
  .topic-subtopics-toggle {
    pointer-events: none;
    cursor: default;
  }

  .topic-subtopics-chevron {
    display: none;
  }

  .topic-subtopics-body {
    max-height: none !important;
    opacity: 1 !important;
  }
}

@media (min-width: 1025px) {
  .topic-subtopics-body {
    max-height: 480px;
    opacity: 1;
  }

  .topic-subtopics.is-collapsed .topic-subtopics-body {
    max-height: 0;
    opacity: 0;
  }

  .topic-subtopics.is-collapsed .topic-subtopics-toggle {
    margin-bottom: 0;
  }

  .topic-subtopics.is-collapsed .topic-subtopics-chevron {
    transform: rotate(-90deg);
  }
}

.topic-subtopic-pill {
  display: inline-flex;
  align-items: center;
  padding: 0.45rem 0.9rem;
  border-radius: var(--radius-pill);
  border: 1px solid var(--color-border);
  background: var(--color-bg);
  color: var(--color-text-muted);
  font-size: 0.82rem;
  font-weight: 600;
  font-family: inherit;
  text-decoration: none;
  cursor: pointer;
  transition: background 0.15s, color 0.15s, border-color 0.15s;
}

button.topic-subtopic-pill {
  margin: 0;
  appearance: none;
  -webkit-appearance: none;
}

.topic-subtopic-pill:hover {
  background: var(--color-teal-muted);
  color: var(--color-teal-dark);
  text-decoration: none;
}

.topic-subtopic-pill.active {
  background: var(--color-teal);
  border-color: var(--color-teal);
  color: #fff;
}

/* Mobile banner tweaks */
@media (max-width: 768px) {
  .topic-banner {
    margin-top: 0.65rem;
    border-radius: 14px;
  }
}