:root {
  --bg: #f5f7fb;
  --card: #ffffff;
  --text: #172033;
  --muted: #667085;
  --line: #e5e7eb;
  --primary: #2563eb;
  --primary-soft: #eaf1ff;
  --shadow: 0 14px 40px rgba(15, 23, 42, 0.08);
  --radius: 22px;
}

* {
  box-sizing: border-box;
}

html,
body {
  width: 100%;
  min-height: 100%;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  overflow-x: hidden;
}

button {
  font: inherit;
  -webkit-tap-highlight-color: transparent;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.page {
  width: 100%;
  max-width: 1380px;
  margin: 0 auto;
  padding: 30px 24px 60px;
  display: grid;
  grid-template-columns: 250px minmax(0, 1fr);
  gap: 24px;
}

.sidebar {
  position: sticky;
  top: 24px;
  align-self: start;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 18px;
}

.side-section + .side-section {
  margin-top: 22px;
  padding-top: 20px;
  border-top: 1px solid var(--line);
}

.side-title {
  margin: 0 0 12px;
  font-size: 14px;
  color: var(--muted);
  font-weight: 700;
}

.filter-list {
  display: grid;
  gap: 8px;
}

.filter-btn {
  width: 100%;
  border: 0;
  cursor: pointer;
  border-radius: 14px;
  background: transparent;
  padding: 11px 12px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--text);
  transition: 0.2s ease;
}

.filter-btn:hover,
.filter-btn.active {
  background: var(--primary-soft);
  color: var(--primary);
}

.count {
  color: var(--muted);
  font-size: 12px;
}

.tag-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tag-btn,
.pill {
  border: 1px solid var(--line);
  background: #fff;
  color: var(--muted);
  border-radius: 999px;
  padding: 7px 11px;
  font-size: 12px;
}

.tag-btn {
  cursor: pointer;
  transition: 0.2s ease;
  white-space: nowrap;
}

.tag-btn:hover,
.tag-btn.active {
  background: var(--primary);
  border-color: var(--primary);
  color: #fff;
}

.main {
  min-width: 0;
}

.main-head {
  display: flex;
  justify-content: space-between;
  align-items: end;
  gap: 16px;
  margin-bottom: 18px;
}

.main-head h1 {
  margin: 0;
  font-size: 30px;
  line-height: 1.2;
  letter-spacing: -0.04em;
}

.main-head p {
  margin: 8px 0 0;
  color: var(--muted);
  font-size: 14px;
}

.mobile-filters {
  display: none;
  gap: 10px;
  overflow-x: auto;
  padding: 2px 2px 16px;
  margin: 0 -2px;
  scrollbar-width: none;
  scroll-snap-type: x proximity;
  -webkit-overflow-scrolling: touch;
}

.mobile-filters::-webkit-scrollbar {
  display: none;
}

.mobile-filters .tag-btn {
  scroll-snap-align: start;
  flex: 0 0 auto;
}

.grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.topic-card {
  min-width: 0;
  overflow: hidden;
  border: 1px solid var(--line);
  background: var(--card);
  border-radius: var(--radius);
  box-shadow: 0 8px 24px rgba(15, 23, 42, 0.05);
  transition: transform 0.22s ease, box-shadow 0.22s ease, border-color 0.22s ease;
}

.topic-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow);
  border-color: rgba(37, 99, 235, 0.28);
}

.card-swiper-wrap {
  position: relative;
  background: #e5e7eb;
  overflow: hidden;
  border-radius: var(--radius) var(--radius) 0 0;
}

.card-swiper {
  width: 100%;
  aspect-ratio: 4 / 3;
  overflow: hidden;
}

.card-swiper .swiper-slide {
  background: #e5e7eb;
  cursor: zoom-in;
}

.card-swiper img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  user-select: none;
}

.image-count {
  position: absolute;
  left: 12px;
  top: 12px;
  z-index: 4;
  background: rgba(17, 24, 39, 0.72);
  color: #fff;
  border-radius: 999px;
  padding: 6px 10px;
  font-size: 12px;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  pointer-events: none;
}

.zoom-hint {
  position: absolute;
  right: 12px;
  top: 12px;
  z-index: 4;
  background: rgba(255, 255, 255, 0.92);
  color: var(--text);
  border-radius: 999px;
  padding: 6px 10px;
  font-size: 12px;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  pointer-events: none;
  opacity: 0;
  transform: translateY(-4px);
  transition: 0.2s ease;
}

.topic-card:hover .zoom-hint {
  opacity: 1;
  transform: translateY(0);
}

.card-swiper .swiper-button-prev,
.card-swiper .swiper-button-next {
  width: 38px;
  height: 38px;
  margin-top: 0;
  transform: translateY(-50%);
  border-radius: 999px;
  border: 1px solid rgba(255, 255, 255, 0.24);
  background: rgba(15, 23, 42, 0.36);
  color: #fff;
  box-shadow: 0 10px 24px rgba(15, 23, 42, 0.16);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  opacity: 0;
  transition: opacity 0.2s ease, background 0.2s ease, transform 0.2s ease;
  z-index: 8;
  overflow: hidden;
}

.card-swiper .swiper-button-prev {
  left: 14px;
}

.card-swiper .swiper-button-next {
  right: 14px;
}

.topic-card:hover .card-swiper .swiper-button-prev,
.topic-card:hover .card-swiper .swiper-button-next,
.card-swiper .swiper-button-prev:focus-visible,
.card-swiper .swiper-button-next:focus-visible {
  opacity: 1;
}

.card-swiper .swiper-button-prev:hover,
.card-swiper .swiper-button-next:hover {
  background: rgba(15, 23, 42, 0.58);
  transform: translateY(-50%) scale(1.05);
}

.card-swiper .swiper-button-prev:active,
.card-swiper .swiper-button-next:active {
  transform: translateY(-50%) scale(0.96);
}

/* 隐藏 Swiper 默认箭头图标，只使用 CSS 绘制图标，避免本地 file:// 打开时请求 SVG 图标导致 CORS 报错 */
.card-swiper .swiper-button-prev::after,
.card-swiper .swiper-button-next::after,
.lightbox-swiper .swiper-button-prev::after,
.lightbox-swiper .swiper-button-next::after {
  content: none !important;
  display: none !important;
}

.card-swiper .swiper-button-prev svg,
.card-swiper .swiper-button-next svg,
.lightbox-swiper .swiper-button-prev svg,
.lightbox-swiper .swiper-button-next svg {
  display: none !important;
}

.card-swiper .swiper-button-prev::before,
.card-swiper .swiper-button-next::before,
.lightbox-swiper .swiper-button-prev::before,
.lightbox-swiper .swiper-button-next::before {
  content: "";
  display: block;
  border-top: solid currentColor;
  border-right: solid currentColor;
  border-radius: 1px;
}

.card-swiper .swiper-button-prev::before,
.card-swiper .swiper-button-next::before {
  width: 11px;
  height: 11px;
  border-top-width: 2.3px;
  border-right-width: 2.3px;
}

.card-swiper .swiper-button-prev::before {
  transform: rotate(-135deg);
  margin-left: 4px;
}

.card-swiper .swiper-button-next::before {
  transform: rotate(45deg);
  margin-right: 4px;
}

.card-swiper .swiper-button-disabled {
  display: none;
}

.card-swiper .swiper-pagination {
  bottom: 11px;
  line-height: 1;
}

.card-swiper .swiper-pagination-bullet {
  width: 7px;
  height: 7px;
  background: rgba(255, 255, 255, 0.76);
  opacity: 1;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.22);
  transition: width 0.2s ease, background 0.2s ease;
}

.card-swiper .swiper-pagination-bullet-active {
  width: 22px;
  border-radius: 999px;
  background: #fff;
}

.card-body {
  padding: 15px 16px 16px;
}

.meta-row {
  display: flex;
  justify-content: space-between;
  gap: 10px;
  align-items: center;
  margin-bottom: 10px;
}

.category {
  color: var(--primary);
  background: var(--primary-soft);
  border-radius: 999px;
  padding: 5px 9px;
  font-size: 12px;
  font-weight: 700;
  white-space: nowrap;
}

.date {
  color: var(--muted);
  font-size: 12px;
  white-space: nowrap;
}

.topic-card h2 {
  margin: 0 0 10px;
  font-size: 17px;
  line-height: 1.35;
}

.tag-row {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
}

.empty {
  min-height: 320px;
  border: 1px dashed #cbd5e1;
  border-radius: var(--radius);
  display: none;
  place-items: center;
  text-align: center;
  color: var(--muted);
  background: rgba(255, 255, 255, 0.65);
}

.empty.show {
  display: grid;
}

.lightbox {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: none;
  background: rgba(15, 23, 42, 0.84);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  padding: 20px;
}

.lightbox.show {
  display: grid;
  grid-template-rows: auto minmax(0, 1fr) auto;
  gap: 14px;
}

.lightbox-top,
.lightbox-swiper,
.lightbox-bottom {
  width: min(1180px, 100%);
}

.lightbox-top {
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 18px;
  color: #fff;
}

.lightbox-title {
  min-width: 0;
}

.lightbox-title h2 {
  margin: 0;
  font-size: 18px;
  line-height: 1.35;
}

.lightbox-title p {
  margin: 4px 0 0;
  color: rgba(255, 255, 255, 0.72);
  font-size: 13px;
}

.close-btn {
  position: relative;
  width: 46px;
  height: 46px;
  border-radius: 999px;
  border: 1px solid rgba(255, 255, 255, 0.22);
  background: rgba(255, 255, 255, 0.1);
  color: #fff;
  cursor: pointer;
  flex: 0 0 auto;
  font-size: 0;
  box-shadow: 0 14px 34px rgba(0, 0, 0, 0.18);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: background 0.2s ease, border-color 0.2s ease, transform 0.2s ease;
}

.close-btn:hover {
  border-color: rgba(255, 255, 255, 0.34);
  background: rgba(255, 255, 255, 0.2);
  transform: scale(1.05);
}

.close-btn:active {
  transform: scale(0.96);
}

.close-btn::before,
.close-btn::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 50%;
  width: 17px;
  height: 2.2px;
  background: #fff;
  border-radius: 999px;
  transform-origin: center;
}

.close-btn::before {
  transform: translate(-50%, -50%) rotate(45deg);
}

.close-btn::after {
  transform: translate(-50%, -50%) rotate(-45deg);
}

.lightbox-swiper {
  height: 100%;
  min-height: 0;
  margin: 0 auto;
  border-radius: 18px;
}

.lightbox-swiper .swiper-slide {
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.lightbox-swiper .swiper-zoom-container {
  width: 100%;
  height: 100%;
  cursor: zoom-in;
}

.lightbox-swiper .swiper-zoom-container img {
  max-width: 100%;
  max-height: 100%;
  object-fit: contain;
  border-radius: 18px;
  box-shadow: 0 24px 80px rgba(0, 0, 0, 0.42);
  background: #fff;
  user-select: none;
}

.lightbox-swiper .swiper-button-prev,
.lightbox-swiper .swiper-button-next {
  width: 52px;
  height: 52px;
  margin-top: 0;
  transform: translateY(-50%);
  border-radius: 999px;
  border: 1px solid rgba(255, 255, 255, 0.22);
  background: rgba(255, 255, 255, 0.1);
  color: #fff;
  box-shadow: 0 14px 34px rgba(0, 0, 0, 0.22);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: background 0.2s ease, border-color 0.2s ease, transform 0.2s ease, opacity 0.2s ease;
  z-index: 8;
  overflow: hidden;
}

.lightbox-swiper .swiper-button-prev {
  left: 16px;
}

.lightbox-swiper .swiper-button-next {
  right: 16px;
}

.lightbox-swiper .swiper-button-prev:hover,
.lightbox-swiper .swiper-button-next:hover {
  border-color: rgba(255, 255, 255, 0.34);
  background: rgba(255, 255, 255, 0.2);
  transform: translateY(-50%) scale(1.05);
}

.lightbox-swiper .swiper-button-prev:active,
.lightbox-swiper .swiper-button-next:active {
  transform: translateY(-50%) scale(0.96);
}

.lightbox-swiper .swiper-button-prev::before,
.lightbox-swiper .swiper-button-next::before {
  width: 14px;
  height: 14px;
  border-top-width: 2.6px;
  border-right-width: 2.6px;
}

.lightbox-swiper .swiper-button-prev::before {
  transform: rotate(-135deg);
  margin-left: 5px;
}

.lightbox-swiper .swiper-button-next::before {
  transform: rotate(45deg);
  margin-right: 5px;
}

.lightbox-bottom {
  margin: 0 auto;
  min-height: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.lightbox-pagination .swiper-pagination-bullet {
  background: rgba(255, 255, 255, 0.52);
  opacity: 1;
}

.lightbox-pagination .swiper-pagination-bullet-active {
  width: 24px;
  border-radius: 999px;
  background: #fff;
}

@media (max-width: 1180px) {
  .grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 860px) {
  .page {
    grid-template-columns: minmax(0, 1fr);
    padding: 20px 16px 44px;
  }

  .sidebar {
    display: none;
  }

  .mobile-filters {
    display: flex;
  }

  .main-head {
    align-items: start;
    flex-direction: column;
    margin-bottom: 16px;
  }

  .main-head h1 {
    font-size: 25px;
  }

  .topic-card:hover {
    transform: none;
  }

  .card-swiper .swiper-button-prev,
  .card-swiper .swiper-button-next {
    width: 34px;
    height: 34px;
    opacity: 1;
    background: rgba(15, 23, 42, 0.34);
  }

  .card-swiper .swiper-button-prev {
    left: 10px;
  }

  .card-swiper .swiper-button-next {
    right: 10px;
  }

  .card-swiper .swiper-button-prev::before,
  .card-swiper .swiper-button-next::before {
    width: 10px;
    height: 10px;
    border-top-width: 2.2px;
    border-right-width: 2.2px;
  }

  .zoom-hint {
    display: none;
  }
}

@media (max-width: 560px) {
  .page {
    padding: 18px 12px 36px;
  }

  .main-head h1 {
    font-size: 23px;
  }

  .main-head p {
    font-size: 13px;
  }

  .grid {
    grid-template-columns: minmax(0, 1fr);
    gap: 16px;
  }

  .topic-card {
    border-radius: 18px;
  }

  .card-swiper-wrap {
    border-radius: 18px 18px 0 0;
  }

  .card-swiper {
    aspect-ratio: 4 / 3;
  }

  .image-count {
    left: 10px;
    top: 10px;
    padding: 5px 9px;
    font-size: 12px;
  }

  .card-body {
    padding: 14px 16px 16px;
  }

  .topic-card h2 {
    font-size: 17px;
  }

  .tag-row {
    gap: 8px;
  }

  .pill {
    padding: 7px 10px;
  }

  .lightbox {
    padding: 10px;
  }

  .lightbox.show {
    gap: 10px;
  }

  .lightbox-title h2 {
    font-size: 16px;
  }

  .lightbox-title p {
    font-size: 12px;
  }

  .close-btn {
    width: 40px;
    height: 40px;
  }

  .close-btn::before,
  .close-btn::after {
    width: 16px;
  }

  .lightbox-swiper .swiper-button-prev,
  .lightbox-swiper .swiper-button-next {
    width: 44px;
    height: 44px;
  }

  .lightbox-swiper .swiper-button-prev {
    left: 8px;
  }

  .lightbox-swiper .swiper-button-next {
    right: 8px;
  }

  .lightbox-swiper .swiper-button-prev::before,
  .lightbox-swiper .swiper-button-next::before {
    width: 12px;
    height: 12px;
    border-top-width: 2.4px;
    border-right-width: 2.4px;
  }
}