:root {
  --bg-light: #f4f5f7; --bg-dark: #121212; --text-light: #111; --text-dark: #f1f1f1;
  --text-muted-light: #555; --text-muted-dark: #aaa; --accent: #007aff;
  --glass-bg-light: rgba(255, 255, 255, 0.65); --glass-bg-dark: rgba(28, 28, 30, 0.75);
  --border-light: rgba(0, 0, 0, 0.1); --border-dark: rgba(255, 255, 255, 0.15);
  --dropdown-bg-light: #ffffff; --dropdown-bg-dark: #2c2c2e;
  --dropdown-shadow: 0 8px 20px rgba(0, 0, 0, 0.12);
  --card-bg-light: #ffffff; --card-bg-dark: #1e1e1e;
}
body { 
  display: flex; flex-direction: column; min-height: 100vh; margin: 0; padding-top: 65px; 
  background-color: var(--bg-light); color: var(--text-light); 
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, "Open Sans", "Helvetica Neue", sans-serif; 
  overflow-y: scroll;
}
body.dark { background-color: var(--bg-dark); color: var(--text-dark); }
body.mobile-nav-active { overflow: hidden; }
main { flex-grow: 1; width: 100%; box-sizing: border-box; }

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-light); border-bottom: 1px solid var(--border-light); 
  backdrop-filter: blur(14px) saturate(180%); -webkit-backdrop-filter: blur(14px) saturate(180%); 
}
body.dark header { background-color: var(--glass-bg-dark); border-bottom: 1px solid var(--border-dark); }
.logo-link { display: flex; flex-shrink: 0; align-items: center; gap: 12px; text-decoration: none; color: inherit; }
.logo-img { height: 32px; }
header h1 { margin: 0; font-weight: 700; font-size: 1.6rem; color: var(--text-light); white-space: nowrap; }
body.dark header h1 { color: var(--text-dark); }

#mainNav { 
  flex-grow: 1;
  flex-shrink: 1;
  display: flex; 
  align-items: center; 
  gap: 16px; 
  height: 100%; 
  list-style: none; 
  margin: 0 0 0 24px; 
  padding: 0; 
  overflow: hidden;
  -webkit-mask-image: linear-gradient(to right, #000 95%, transparent 100%);
  mask-image: linear-gradient(to right, #000 95%, transparent 100%);
}

#mainNav-inner-container {
  display: flex;
  align-items: center;
  height: 100%;
  transition: transform 0.5s ease-out;
}

.nav-group { position: relative; display: flex; align-items: center; height: 100%; }
.group-btn { 
  position: relative;
  display: flex; align-items: center; gap: 5px; padding: 0 16px; height: 100%; border: none; background: transparent; 
  color: var(--text-muted-light); font-size: 1rem; font-weight: 500; cursor: pointer; transition: color 0.3s ease; white-space: nowrap; 
}
body.dark .group-btn { color: var(--text-muted-dark); }
.group-btn::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 2px;
  background-color: var(--accent);
  transform: scaleX(0);
  transition: transform 0.3s cubic-bezier(0.19, 1, 0.22, 1);
}
.group-btn.active, .nav-group:hover .group-btn { color: var(--text-light); }
body.dark .group-btn.active, body.dark .nav-group:hover .group-btn { color: var(--text-dark); }
.group-btn.active::after, .nav-group:hover .group-btn::after { transform: scaleX(1); }

.nav-group > .group-btn span + span { display: none; }
.category-list { 
  position: absolute; top: 100%; left: 50%; padding: 8px; margin: 0; margin-top: 8px; min-width: 160px; 
  background: var(--dropdown-bg-light); border-radius: 12px; box-shadow: var(--dropdown-shadow); list-style: none; 
  z-index: 1001; opacity: 0; visibility: hidden; transition: opacity 0.2s ease, transform 0.2s ease, visibility 0.2s; 
  transform: translateX(-50%) translateY(-10px); display: flex; flex-direction: column; gap: 4px; 
}
body.dark .category-list { background: var(--dropdown-bg-dark); }
.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-light); border-radius: 8px; cursor: pointer; font-size: 0.95rem; 
  transition: color 0.2s, background-color 0.2s; text-decoration: none; 
}
body.dark .category-btn { color: var(--text-dark); }
.category-btn.active, .category-btn:hover { background-color: var(--accent); color: white !important; }
#productsNav { display: flex; flex-shrink: 0; height: 100%; list-style: none; margin: 0; padding: 0; margin-left: 16px;}
#productsNav .nav-group:hover .group-btn::after { transform: none; }
#productsNav .nav-group .group-btn::after { content: '▾'; position: static; transform: none; background: none; height: auto; transition: transform 0.2s ease; opacity: 0.6; font-size: 0.8em; }
#productsNav .nav-group:hover .group-btn::after { transform: rotate(180deg); }
.nav-group-container { display:flex; height:100%; list-style:none; margin:0; padding:0; }
.product-list .category-btn { display: block; text-decoration: none; color: var(--text-light); }
body.dark .product-list .category-btn { color: var(--text-dark); }
.product-list .category-btn:hover, .product-list .category-btn.active { background-color: var(--accent); color: white !important; }

header .search-container { flex-shrink: 0; margin-left: auto; margin-right: 16px; position: relative; display: flex; align-items: center; }
.search-icon { position: absolute; left: 14px; top: 50%; transform: translateY(-50%); color: var(--text-muted-light); transition: color .2s; }
body.dark .search-icon { color: var(--text-muted-dark); }
.search-container:focus-within .search-icon { color: var(--accent); }
header #searchInput {
  background-color: var(--bg-light); border: 1px solid var(--border-light); border-radius: 20px;
  width: 240px; height: 40px; padding: 0 20px 0 42px; font-size: .9rem; color: var(--text-light); transition: all .3s ease;
}
body.dark #searchInput { background-color: var(--card-bg-dark); border-color: var(--border-dark); color: var(--text-dark); }
#searchInput:focus {
  outline: 0; border-color: var(--accent); background-color: var(--card-bg-light); box-shadow: 0 0 0 3px rgba(0,122,255,.2); width: 280px;
}
body.dark #searchInput:focus { background-color: var(--bg-dark); }

.header-right-actions { display: flex; align-items: center; margin-left: 12px; }
#themeToggle { 
  flex-shrink: 0;
  display: flex; justify-content: center; align-items: center; background: transparent; border: none; 
  padding: 8px; border-radius: 50%; cursor: pointer; color: var(--text-muted-light); transition: color 0.2s, background-color 0.2s;
}
body.dark #themeToggle { color: var(--text-muted-dark); }
#themeToggle:hover { color: var(--accent); background-color: var(--border-light); }
body.dark #themeToggle:hover { background-color: var(--border-dark); }
#themeToggle svg { stroke: currentColor; fill: none; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }
.sun-icon { display: block; } .moon-icon { display: none; }
body.dark .sun-icon { display: none; } body.dark .moon-icon { display: block; }

.mobile-nav-toggle-btn {
  display: none;
  background: transparent; border: none; padding: 8px; border-radius: 50%;
  cursor: pointer; color: var(--text-muted-light); margin-left: 4px;
}
body.dark .mobile-nav-toggle-btn { color: var(--text-muted-dark); }

footer { 
  width: 100%; margin-top: 40px; padding: 30px 24px; box-sizing: border-box; background: var(--bg-light); 
  border-top: 1px solid var(--border-light); color: var(--text-muted-light);
}
body.dark footer { background: var(--bg-dark); border-top: 1px solid var(--border-dark); color: var(--text-muted-dark); }
.footer-content { max-width: 1200px; margin: 0 auto; text-align: center; font-size: 0.9rem; }
.footer-content p { margin: 8px 0; line-height: 1.6; }
.footer-content a { color: var(--text-muted-light); text-decoration: none; transition: color 0.2s; }
body.dark .footer-content a { color: var(--text-muted-dark); }
.footer-content a:hover { color: var(--accent); }
.donation-section { display: flex; justify-content: center; align-items: center; gap: 15px; margin-bottom: 20px; }
.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(-8px) translateX(-50%); }
.wechat-qr-popup { 
  position: absolute; bottom: 100%; left: 50%; padding: 15px; background: var(--dropdown-bg-light); 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; 
}
body.dark .wechat-qr-popup { background: var(--dropdown-bg-dark); }
.wechat-qr-popup img { width: 240px; height: 240px; display: block; }
footer a { text-decoration: none; }
footer .copyright img { vertical-align: text-bottom; width: 16px; }

#floating-sidebar { 
  position: fixed; top: 50%; right: 20px; transform: translateY(-50%); z-index: 1010; 
  background: var(--glass-bg-light); backdrop-filter: blur(10px) saturate(150%); 
  -webkit-backdrop-filter: blur(10px) saturate(150%); border-radius: 16px; padding: 36px 8px 8px 8px; 
  box-shadow: 0 4px 15px rgba(0,0,0,0.1); border: 1px solid var(--border-light); 
  transition: all 0.3s ease-in-out; }
#floating-sidebar.is-hidden { opacity: 0; visibility: hidden; transform: translateY(-50%) translateX(120%); pointer-events: none; }
body.dark #floating-sidebar { background: var(--glass-bg-dark); border-color: var(--border-dark); box-shadow: 0 4px 20px rgba(0,0,0,0.3); }
.sidebar-close-btn { 
  position: absolute; top: 6px; right: 6px; width: 24px; height: 24px; border: none; background: transparent; 
  color: var(--text-muted-light); font-size: 1.5rem; line-height: 1; display: flex; align-items: center; 
  justify-content: center; cursor: pointer; border-radius: 50%; transition: background-color 0.2s, color 0.2s, transform 0.2s; z-index: 2; 
}
body.dark .sidebar-close-btn { color: var(--text-muted-dark); }
.sidebar-close-btn:hover { background-color: var(--border-light); color: var(--text-light); transform: rotate(90deg); }
body.dark .sidebar-close-btn:hover { background-color: var(--border-dark); color: var(--text-dark); }
.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(0, 122, 255, 0.1); }
.sidebar-icon { width: 32px; height: 32px; display: block; }
.qr-popup, .tooltip { 
  position: absolute; right: 100%; top: 50%; transform: translateY(-50%) translateX(0px); margin-right: 15px; 
  padding: 15px; background: var(--dropdown-bg-light); 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; }
body.dark .qr-popup, body.dark .tooltip { background: var(--dropdown-bg-dark); }
.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; background-color: white; padding: 5px; box-sizing: border-box; border-radius: 4px; }
.qr-popup span, .tooltip span { font-size: 0.9rem; color: var(--text-light); font-weight: 500; }
body.dark .qr-popup span, body.dark .tooltip span { color: var(--text-dark); }

.prompt-generator-layout {
  display: flex; max-width: 1800px; margin: 0 auto; padding: 20px; gap: 24px; align-items: flex-start;
}
.tag-selector-container { flex: 1; min-width: 0; }
.subcategory-group { margin-bottom: 28px; }
.subcategory-header {
  display: flex; justify-content: space-between; align-items: center; border-bottom: 1px solid var(--border-light); 
  padding-bottom: 10px; margin-bottom: 24px;
}
body.dark .subcategory-header { border-color: var(--border-dark); }
.subcategory-header h3 { font-size: 1.1rem; margin: 0; color: var(--text-light); }
body.dark .subcategory-header h3 { color: var(--text-dark); }
.toggle-collapse-btn {
  background: transparent; border: 1px solid var(--border-light); color: var(--text-muted-light); 
  padding: 4px 10px; border-radius: 6px; cursor: pointer; font-size: .85rem; transition: all .2s;
}
body.dark .toggle-collapse-btn { border-color: var(--border-dark); color: var(--text-muted-dark); }
.toggle-collapse-btn:hover { color: var(--accent); border-color: var(--accent); }
.tags-wrapper {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  max-height: 170px;
  overflow: hidden;
  transition: max-height .5s ease-in-out;
  padding-top: 5px;
  margin-top: -5px;
}
.tags-wrapper.is-expanded { max-height: 2000px; }
.tag-chip {
  position: relative;
  display: flex; align-items: center; padding: 6px 12px; 
  background-color: var(--card-bg-light);
  border: 1px solid var(--border-light); border-radius: 18px; cursor: pointer; 
  transition: all .25s ease; font-size: .9rem; user-select: none; box-shadow: 0 2px 4px rgba(0,0,0,.04);
}
body.dark .tag-chip {
  background-color: var(--card-bg-dark);
  border-color: var(--border-dark);
  box-shadow: none;
}
.tag-chip.is-selected {
  border-color: var(--accent);
  color: var(--accent);
}
.tag-chip:hover {
  transform: translateY(-2px) scale(1.02);
  border-color: var(--accent);
  color: var(--accent); 
  box-shadow: 0 6px 12px rgba(0,122,255,.1);
  z-index: 1;
}
.tag-chip .zh { font-weight: normal; margin-right: 6px; }
.tag-chip .en { font-size: .8rem; color: var(--text-muted-light); opacity: .8; }
body.dark .tag-chip .en { color: var(--text-muted-dark); }

.prompt-workspace-container { width: 420px; position: sticky; top: 85px; align-self: flex-start; height: calc(100vh - 125px); }
.prompt-workspace {
  background: var(--card-bg-light); border-radius: 12px; border: 1px solid var(--border-light);
  padding: 20px; height: 100%; display: flex; flex-direction: column; box-shadow: 0 8px 30px rgba(0,0,0,.08);
}
body.dark .prompt-workspace { background: var(--bg-dark); border-color: var(--border-dark); box-shadow: 0 8px 30px rgba(0,0,0,.2); }
.workspace-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 12px; }
.workspace-header h3 { margin: 0; font-size: 1rem; font-weight: 600; }
.workspace-controls { display: flex; align-items: center; gap: 8px; }
.workspace-controls button {
  padding: 6px 14px; font-size: .85rem; border-radius: 8px; cursor: pointer; 
  border: 1px solid var(--border-light); background: var(--bg-light); color: var(--text-light); font-weight: 500; transition: all .2s;
}
body.dark .workspace-controls button { border-color: var(--border-dark); background: var(--card-bg-dark); color: var(--text-dark); }
.workspace-controls button:hover { background: var(--accent); color: #fff; border-color: var(--accent); transform: scale(1.05); }
.workspace-controls button:disabled {
  cursor: not-allowed; opacity: .5; transform: none; background: var(--bg-light); 
  color: var(--text-light); border-color: var(--border-light);
}

.lang-toggle {
    display: flex;
    align-items: center;
}
.lang-switch-checkbox {
    display: none;
}
.lang-switch-label {
    display: flex;
    align-items: center;
    padding: 3px;
    width: 68px;
    height: 32px;
    background-color: var(--bg-light);
    border: 1px solid var(--border-light);
    border-radius: 16px;
    position: relative;
    cursor: pointer;
    transition: background-color 0.3s ease, border-color 0.3s ease;
    box-sizing: border-box;
}
body.dark .lang-switch-label {
    background-color: var(--card-bg-dark);
    border-color: var(--border-dark);
}
.lang-switch-inner {
    width: 100%;
    position: absolute;
    left: 0; top: 0;
    display: flex;
    justify-content: space-around;
    align-items: center;
    line-height: 30px;
    font-size: 0.9rem;
    font-weight: 500;
}
.lang-switch-inner::before, .lang-switch-inner::after {
    transition: color 0.3s ease;
}
.lang-switch-inner::before { 
    content: "中";
    color: var(--text-light);
}
.lang-switch-inner::after { 
    content: "英";
    color: var(--text-muted-light);
}
body.dark .lang-switch-inner::before {
    color: var(--text-dark);
}
body.dark .lang-switch-inner::after {
    color: var(--text-muted-dark);
}
.lang-switch-switch {
    width: 26px;
    height: 26px;
    background: #fff;
    border-radius: 50%;
    box-shadow: 0 1px 3px rgba(0,0,0,0.15);
    position: absolute;
    top: 2px;
    left: 2px;
    transition: transform 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    z-index: 1;
}
body.dark .lang-switch-switch {
    background: var(--bg-dark);
    box-shadow: 0 1px 4px rgba(0,0,0,0.3), inset 0 0 0 1px var(--border-dark);
}
.lang-switch-checkbox:checked + .lang-switch-label .lang-switch-switch {
    transform: translateX(36px);
}
.lang-switch-checkbox:checked + .lang-switch-label .lang-switch-inner::before {
    color: var(--text-muted-light);
}
.lang-switch-checkbox:checked + .lang-switch-label .lang-switch-inner::after {
    color: var(--text-light);
}
body.dark .lang-switch-checkbox:checked + .lang-switch-label .lang-switch-inner::before {
    color: var(--text-muted-dark);
}
body.dark .lang-switch-checkbox:checked + .lang-switch-label .lang-switch-inner::after {
    color: var(--text-dark);
}


textarea {
  flex-grow: 1; width: 100%; box-sizing: border-box; padding: 12px; border-radius: 8px; 
  border: 1px solid var(--border-light); background-color: var(--bg-light); color: var(--text-light);
  font-family: Menlo, Monaco, Consolas, "Courier New", monospace; font-size: .9rem; line-height: 1.6; resize: none; 
  margin-bottom: 20px; transition: all .2s;
}
body.dark textarea { background-color: var(--bg-dark); color: var(--text-dark); border-color: var(--border-dark); }
:focus-visible { outline: 0; }
textarea:focus {
  border-color: var(--accent); box-shadow: 0 0 0 3px rgba(0,122,255,.2); background-color: var(--card-bg-light);
}
body.dark textarea:focus { background-color: var(--bg-dark); }
.search-results-container { display: flex; flex-wrap: wrap; gap: 10px; }


#mobileNavOverlay { position: fixed; top: 0; left: 0; width: 100%; height: 100%; background: rgba(0, 0, 0, 0.5); z-index: 1050; opacity: 0; visibility: hidden; transition: opacity 0.3s ease, visibility 0.3s; }
#mobileNavOverlay.open { opacity: 1; visibility: visible; }
#mobileNavContainer { position: fixed; top: 0; left: 0; width: 280px; height: 100%; background-color: var(--bg-light); z-index: 1060; transform: translateX(-100%); transition: transform 0.3s ease-in-out; display: flex; flex-direction: column; }
body.dark #mobileNavContainer { background-color: var(--card-bg-dark); }
#mobileNavContainer.open { transform: translateX(0); }
.mobile-nav-header { display: flex; justify-content: space-between; align-items: center; padding: 0 20px; height: 65px; border-bottom: 1px solid var(--border-light); flex-shrink: 0; }
body.dark .mobile-nav-header { border-bottom: 1px solid var(--border-dark); }
.mobile-nav-title { font-size: 1.2rem; font-weight: 600; }
#mobileNavCloseBtn { font-size: 2.5rem; line-height: 1; border: none; background: transparent; color: var(--text-muted-light); cursor: pointer; padding: 0; }
body.dark #mobileNavCloseBtn { color: var(--text-muted-dark); }
#mobileNavContent { overflow-y: auto; padding: 15px 0; }
#mobileNavContent ul { list-style: none; padding: 0; margin: 0; }
#mobileNavContent .mobile-nav-group-btn { display: block; width: 100%; padding: 15px 20px; border: none; background: transparent; text-align: left; font-size: 1rem; font-weight: 500; cursor: pointer; color: var(--text-light); }
body.dark #mobileNavContent .mobile-nav-group-btn { color: var(--text-dark); }
#mobileNavContent .mobile-nav-group-btn.active { color: var(--accent); background-color: rgba(0,122,255,0.1); }
#mobileNavContent .mobile-nav-group-btn.is-expandable { display: flex; justify-content: space-between; align-items: center; }
#mobileNavContent .mobile-nav-group-btn.is-expandable::after { content: '›'; font-size: 1.2rem; opacity: 0.6; transition: transform 0.2s ease; }
#mobileNavContent .mobile-nav-group-btn.expanded::after { transform: rotate(90deg); }
#mobileNavContent .mobile-category-list { padding-left: 20px; max-height: 0; overflow: hidden; transition: max-height 0.3s ease-in-out; list-style: none; margin: 0; }
#mobileNavContent .mobile-category-list.expanded { max-height: 500px; }
#mobileNavContent .mobile-category-btn { display: block; width: 100%; padding: 12px 20px; font-size: 0.95rem; text-decoration: none; text-align: left; background: transparent; border: none; border-radius: 0; cursor: pointer; color: var(--text-muted-light); }
body.dark #mobileNavContent .mobile-category-btn { color: var(--text-muted-dark); }
#mobileNavContent .mobile-category-btn.active, #mobileNavContent .mobile-category-btn:hover { color: var(--accent); background-color: rgba(0,122,255,0.05); }

@media (max-width: 1024px) {
  .prompt-generator-layout { flex-direction: column; }
  .prompt-workspace-container { position: relative; top: 0; width: 100%; height: auto; margin-top: 20px; }
  .prompt-workspace { height: auto; }
  #mainNav, #productsNav { display: none; }
  .mobile-nav-toggle-btn { display: block; }
  header .search-container { margin-left: 16px; flex-grow: 1; }
  header #searchInput { width: 100%; }
  header #searchInput:focus { width: 100%; }
}
@media (max-width: 768px) {
  body { padding-top: 60px; }
  header { height: 60px; padding: 0 16px; }
  header h1 { display: none; }
  .logo-link { margin-right: 16px; }
  .prompt-generator-layout { padding: 10px; gap: 15px; }
  header .search-container { margin-left: 0; }
  .prompt-workspace-container { margin-top: 10px; }
  .workspace-controls button { padding: 6px 10px; font-size: 0.8rem; }
  .lang-switch-label { width: 60px; height: 30px; }
  .lang-switch-switch { width: 24px; height: 24px; }
  .lang-switch-checkbox:checked + .lang-switch-label .lang-switch-switch { transform: translateX(30px); }
  .lang-switch-inner { line-height: 28px; }
}