:root {
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue", "PingFang SC", "Microsoft YaHei", sans-serif;
  --accent: #007aff;
  --accent-rgb: 0, 122, 255;
  --bg-light: #f7f8fa;
  --bg-dark: #121212;
  --text-light: #1f2328;
  --text-dark: #e6edf3;
  --text-muted-light: #57606a;
  --text-muted-dark: #848d97;
  --glass-bg-light: rgba(255, 255, 255, 0.7);
  --glass-bg-dark: rgba(22, 22, 22, 0.75);
  --border-light: rgba(0, 0, 0, 0.08);
  --border-dark: rgba(255, 255, 255, 0.15);
  --dropdown-bg-light: #ffffff;
  --dropdown-bg-dark: #2c2c2e;
  --dropdown-shadow: 0 12px 28px rgba(0, 0, 0, 0.15);
  --card-bg-light: #fff;
  --card-bg-dark: #1e1e1e;
  --input-bg-light: #eef0f2;
  --input-bg-dark: #282828;

  --bg: var(--bg-light);
  --text-primary: var(--text-light);
  --text-secondary: var(--text-muted-light);
  --glass-bg: var(--glass-bg-light);
  --border-color: var(--border-light);
  --dropdown-bg: var(--dropdown-bg-light);
  --card-bg: var(--card-bg-light);
  --input-bg: var(--input-bg-light);
}
html.dark {
  --bg: var(--bg-dark);
  --text-primary: var(--text-dark);
  --text-secondary: var(--text-muted-dark);
  --glass-bg: var(--glass-bg-dark);
  --border-color: var(--border-dark);
  --dropdown-bg: var(--dropdown-bg-dark);
  --card-bg: var(--card-bg-dark);
  --input-bg: var(--input-bg-dark);
}
body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  margin: 0;
  padding-top: 65px;
  background-color: var(--bg);
  color: var(--text-primary);
  font-family: var(--font-sans);
  transition: background-color 0.3s ease, color 0.3s ease;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
main {
  flex-grow: 1;
  padding: 24px;
  max-width: 1680px;
  width: 100%;
  box-sizing: border-box;
  margin: 0 auto;
}
header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  display: flex;
  align-items: center;
  padding: 0 24px;
  height: 65px;
  background-color: var(--glass-bg);
  border-bottom: 1px solid var(--border-color);
  backdrop-filter: blur(16px) saturate(180%);
  -webkit-backdrop-filter: blur(16px) saturate(180%);
  transition: background-color 0.3s ease, border-color 0.3s ease;
  gap: 16px;
}
.logo-link {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: inherit;
  flex-shrink: 0;
}
.logo-img { height: 32px; }
header h1 {
  margin: 0;
  font-weight: 600;
  font-size: 1.5rem;
  color: var(--text-primary);
  white-space: nowrap;
}
#mainNav, #productsNav {
  display: flex;
  height: 100%;
  list-style: none;
  margin: 0;
  padding: 0;
  flex-shrink: 0;
}
#mainNav { gap: 16px; }
.nav-group {
  position: relative;
  display: flex;
  align-items: center;
}
.group-btn {
  position: relative;
  display: flex;
  align-items: center;
  gap: 5px;
  padding: 0 12px;
  height: 100%;
  border: none;
  background: transparent;
  color: var(--text-secondary);
  font-size: 1rem;
  font-weight: 500;
  cursor: pointer;
  transition: color 0.2s;
  white-space: nowrap;
}
.group-btn::after {
  content: '▾';
  font-size: 0.8em;
  opacity: 0.7;
  transition: transform 0.2s ease;
}
.group-btn.active, .group-btn:hover { color: var(--text-primary); }
.group-btn.active { font-weight: 600; }
.nav-group:hover .group-btn::after { transform: rotate(180deg); }
.category-list {
  position: absolute;
  top: 95%;
  left: 50%;
  padding: 8px;
  margin: 0;
  min-width: 180px;
  background: var(--dropdown-bg);
  border-radius: 12px;
  box-shadow: var(--dropdown-shadow);
  border: 1px solid var(--border-color);
  list-style: none;
  z-index: 1001;
  opacity: 0;
  visibility: hidden;
  display: flex;
  flex-direction: column;
  gap: 4px;
  transition: opacity 0.2s ease, transform 0.2s ease, visibility 0.2s;
  transform: translateX(-50%) translateY(-10px);
}
.nav-group:hover .category-list {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(0);
}
.category-list li { width: 100%; }
.category-btn {
  display: block;
  box-sizing: border-box;
  width: 100%;
  padding: 10px 16px;
  text-align: left;
  border: none;
  background: transparent;
  color: var(--text-primary);
  border-radius: 8px;
  cursor: pointer;
  font-size: 0.95rem;
  font-weight: 500;
  transition: color 0.2s, background-color 0.2s;
  text-decoration: none;
}
.category-btn.active, .category-btn:hover {
  background-color: var(--accent);
  color: white !important;
}
.search-container {
  position: relative;
  display: flex;
  align-items: center;
  width: 320px;
  margin-left: auto;
}
.search-icon {
  position: absolute;
  left: 14px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-secondary);
  pointer-events: none;
}
#searchInput {
  width: 100%;
  height: 40px;
  padding: 0 16px 0 44px;
  border: 1px solid transparent;
  border-radius: 10px;
  background-color: var(--input-bg);
  color: var(--text-primary);
  font-size: 0.95rem;
  transition: all 0.2s ease;
  -webkit-appearance: none;
}
#searchInput:focus {
  outline: none;
  border-color: rgba(var(--accent-rgb), 0.4);
  background-color: var(--card-bg);
  box-shadow: 0 0 0 3px rgba(var(--accent-rgb), 0.15);
}
#searchInput::placeholder { color: var(--text-secondary); }
#themeToggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: var(--input-bg);
  border: none;
  border-radius: 10px;
  cursor: pointer;
  color: var(--text-secondary);
  transition: background-color 0.2s, color 0.2s;
  flex-shrink: 0;
}
#themeToggle:hover { color: var(--text-primary); background-color: var(--border-color); }
#themeToggle .sun-icon { display: block; }
#themeToggle .moon-icon { display: none; }
html.dark #themeToggle .sun-icon { display: none; }
html.dark #themeToggle .moon-icon { display: block; }
.link-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
}
.link-card {
  display: block;
  position: relative;
  text-decoration: none;
  color: inherit;
  background-color: var(--card-bg);
  border-radius: 16px;
  border: 1px solid var(--border-color);
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
  height: 110px;
  box-sizing: border-box;
}
.link-card:hover {
  transform: translateY(-5px);
  border-color: rgba(var(--accent-rgb), 0.3);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
  z-index: 5;
}
html.dark .link-card:hover { box-shadow: 0 8px 24px rgba(0, 0, 0, 0.2); }
.link-card-content {
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  height: 100%;
  box-sizing: border-box;
}
.link-card-header {
  display: flex;
  align-items: center;
  gap: 12px;
}
.link-icon {
  width: 36px;
  height: 36px;
  flex-shrink: 0;
  border-radius: 50%;
  background-color: var(--bg);
  object-fit: contain;
  padding: 2px;
  box-sizing: border-box;
}
.link-name {
  margin: 0;
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.link-desc {
  margin: 0;
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.card-tooltip {
  position: absolute;
  top: calc(100% + 8px);
  left: 50%;
  background: #2f363d;
  color: #e6edf3;
  padding: 10px 16px;
  border-radius: 8px;
  box-shadow: var(--dropdown-shadow);
  font-size: 0.9rem;
  line-height: 1.5;
  text-align: center;
  width: max-content;
  max-width: 280px; 
  white-space: normal;
  z-index: 10;
  pointer-events: none;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.2s ease, transform 0.2s ease, visibility 0.2s ease;
  transform: translateX(-50%) translateY(-8px);
}
.card-tooltip::after {
  content: '';
  position: absolute;
  bottom: 100%;
  left: 50%;
  transform: translateX(-50%);
  border-width: 6px;
  border-style: solid;
  border-color: transparent transparent #2f363d transparent;
}
.link-card:hover .card-tooltip {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(0);
}
.empty-message, .search-fallback {
  grid-column: 1 / -1;
  padding: 80px 20px;
  text-align: center;
  color: var(--text-secondary);
}
.search-fallback {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 20px;
}
.search-fallback p { font-size: 1.15rem; margin: 0; }
.search-fallback strong { color: var(--accent); font-weight: 600; }
footer {
  width: 100%;
  margin-top: 40px;
  padding: 30px 24px;
  box-sizing: border-box;
  background: transparent;
  border-top: 1px solid var(--border-color);
  color: var(--text-secondary);
  font-size: 0.85rem;
}
.footer-content { max-width: 1000px; margin: 0 auto; text-align: center; }
.footer-content p { margin: 8px 0; line-height: 1.7; }
.footer-content a {
  color: var(--text-secondary);
  text-decoration: none;
  transition: color 0.2s;
}
.footer-content a:hover { color: var(--accent); text-decoration: underline; }
.donation-section {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 15px;
  margin-bottom: 20px;
  color: var(--text-primary);
}
.donation-title { font-weight: 500; }
.donation-item { position: relative; display: flex; align-items: center; }
.donation-icon {
  height: 24px;
  width: auto;
  cursor: pointer;
  transition: transform 0.2s ease;
}
.donation-item a:hover .donation-icon, .wechat-donate:hover .donation-icon { transform: scale(1.1); }
.wechat-donate:hover .wechat-qr-popup {
  opacity: 1;
  visibility: visible;
  transform: translateY(-100%) translateY(-12px) translateX(-50%);
}
.wechat-qr-popup {
  position: absolute;
  bottom: 100%;
  left: 50%;
  padding: 15px;
  background: var(--dropdown-bg);
  border-radius: 12px;
  box-shadow: var(--dropdown-shadow);
  opacity: 0;
  visibility: hidden;
  transition: all 0.25s ease-out;
  transform: translateY(-100%) translateY(0) translateX(-50%);
  pointer-events: none;
  border: 1px solid var(--border-color);
}
.wechat-qr-popup img { width: 240px; height: 240px; display: block; }
#floating-sidebar {
  position: fixed;
  top: 50%;
  right: 20px;
  transform: translateY(-50%);
  z-index: 1010;
  background: var(--glass-bg);
  backdrop-filter: blur(10px) saturate(150%);
  -webkit-backdrop-filter: blur(10px) saturate(150%);
  border-radius: 12px;
  padding: 8px;
  padding-top: 36px;
  box-shadow: 0 4px 15px rgba(0,0,0,0.1);
  border: 1px solid var(--border-color);
  transition: all 0.3s ease-in-out;
}
#floating-sidebar.is-hidden {
  opacity: 0;
  visibility: hidden;
  transform: translateY(-50%) translateX(150%);
  pointer-events: none;
  html.dark #floating-sidebar { box-shadow: 0 4px 20px rgba(0,0,0,0.3); }
}
.sidebar-close-btn {
  position: absolute;
  top: 4px;
  right: 4px;
  width: 24px;
  height: 24px;
  border: none;
  background: transparent;
  color: var(--text-secondary);
  font-size: 1.5rem;
  line-height: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  border-radius: 50%;
  transform: rotate(0deg);
  transition: background-color 0.2s, color 0.2s, transform 0.3s ease;
}
.sidebar-close-btn:hover {
  background-color: var(--border-color);
  color: var(--text-primary);
  transform: rotate(90deg);
}
.sidebar-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 15px;
}
.sidebar-item {
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
}
.sidebar-link {
  display: block;
  padding: 4px;
  border-radius: 50%;
  transition: transform 0.2s ease, background-color 0.2s;
}
.sidebar-link:hover { transform: scale(1.1); background-color: rgba(var(--accent-rgb), 0.1); }
.sidebar-icon { width: 32px; height: 32px; display: block; }
.qr-popup, .tooltip {
  position: absolute;
  right: 100%;
  top: 50%;
  transform: translateY(-50%);
  margin-right: 15px;
  padding: 15px;
  background: var(--dropdown-bg);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  box-shadow: var(--dropdown-shadow);
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity 0.25s ease, transform 0.25s ease, visibility 0.25s;
  white-space: nowrap;
  text-align: center;
}
.tooltip { padding: 8px 16px; }
.sidebar-item:hover .qr-popup, .sidebar-item:hover .tooltip {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transform: translateY(-50%) translateX(-10px);
}
.qr-popup img { width: 140px; height: 140px; display: block; margin-bottom: 8px; }
.qr-popup span, .tooltip span { font-size: 0.9rem; color: var(--text-secondary); }
.category-view-container {
  display: flex;
  flex-direction: column;
  gap: 40px;
}
.category-section-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
}
.category-section-title {
  margin: 0;
  padding-left: 12px;
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-primary);
  border-left: 4px solid var(--accent);
  line-height: 1.2;
}
.show-more-btn {
  background: none;
  border: none;
  color: var(--text-secondary);
  font-size: 0.95rem;
  font-weight: 500;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 5px;
  border-radius: 6px;
  transition: color 0.2s, background-color 0.2s;
}
.show-more-btn:hover {
  color: var(--accent);
}
.category-section .link-grid .is-extra-card {
  display: none;
}
.category-section.is-expanded .link-grid .is-extra-card {
  display: block;
}
@media (max-width: 1024px) {
  .search-container { display: none; }
}
@media (max-width: 768px) {
  header { gap: 10px; padding: 0 16px; }
  .logo-link { margin-right: 0; }
  header h1 { display: none; }
  #mainNav { margin-left: 0; gap: 8px; }
  .group-btn { padding: 0 8px; }
  .link-grid {
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 16px;
  }
}
.search-fallback span {
  margin-top: 8px;
  margin-bottom: 24px;
  font-size: 1rem;
}
.search-engine-list {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 15px;
}
.search-engine-btn {
  padding: 10px 24px;
  text-decoration: none;
  color: white;
  border-radius: 8px;
  font-weight: 500;
  transition: all 0.2s ease;
  min-width: 80px;
  text-align: center;
}
.search-engine-btn:hover {
  opacity: 0.85;
  transform: translateY(-2px);
}
.search-engine-btn.baidu { background-color: #2972F8; }
.search-engine-btn.bing { background-color: #007DAA; }
.search-engine-btn.google { background-color: #4285F4; }
.search-engine-btn.sogou { background-color: #F94F40; }
.search-engine-btn.duckduckgo { background-color: #DE5833; }