/* Hero Section */
.hero {
  position: relative;
  isolation: isolate;
  padding: 96px 0;
  background: 
    radial-gradient(1200px 400px at 50% -10%, rgba(233, 30, 99, .25), transparent),
    radial-gradient(1200px 400px at 10% 0, rgba(156, 39, 176, .15), transparent);
  border-bottom: 1px solid var(--border);
}

@media (max-width: 768px) {
  .hero {
    padding: 64px 0;
  }
}

@media (max-width: 480px) {
  .hero {
    padding: 48px 0;
  }
}

.hero .hero-content {
  display: grid;
  gap: 16px;
  max-width: 800px;
  margin: 0 auto;
  text-align: center;
}

.hero-subtitle {
  color: var(--text-secondary);
  font-size: 1.125rem;
}

@media (max-width: 768px) {
  .hero-subtitle {
    font-size: 1rem;
  }
}

/* Category Groups */
.category-group {
  background: linear-gradient(180deg, rgba(255, 255, 255, .02), transparent);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 20px;
  box-shadow: var(--shadow);
  margin-bottom: 24px;
}

@media (max-width: 768px) {
  .category-group {
    padding: 16px;
    border-radius: 14px;
    margin-bottom: 20px;
  }
}

.category-group-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 12px;
}

@media (max-width: 480px) {
  .category-group-header {
    gap: 8px;
  }
}

.category-group-icon {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  background: var(--gradient-brand);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  flex-shrink: 0;
}

@media (max-width: 480px) {
  .category-group-icon {
    width: 36px;
    height: 36px;
  }
}

.category-card {
  background: rgba(255, 255, 255, .02);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 18px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.category-card i {
  color: var(--icon-color);
}

.category-icon i {
  color: var(--icon-color);
}

/* Back to Top Button */
.back-to-top {
  position: fixed;
  bottom: 24px;
  right: 24px;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--gradient-brand);
  border: none;
  color: white;
  font-size: 18px;
  cursor: pointer;
  box-shadow: var(--shadow);
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
}

.back-to-top:hover {
  transform: translateY(0) scale(1.1);
  box-shadow: 0 15px 40px rgba(233, 30, 99, 0.4);
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

@media (max-width: 768px) {
  .back-to-top {
    bottom: 20px;
    right: 20px;
    width: 44px;
    height: 44px;
    font-size: 16px;
  }
}

/* Related Articles Section */
.related-articles {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border);
}

.related-article-card {
  position: relative;
  padding: 24px;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  overflow: hidden;
}

.related-article-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--gradient-brand);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.related-article-card:hover::before {
  transform: scaleX(1);
}

.related-article-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
}

.related-article-card h3 {
  margin: 0 0 8px 0;
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--text);
  transition: color 0.3s ease;
}

.related-article-card:hover h3 {
  background: var(--gradient-brand);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.related-article-arrow {
  position: absolute;
  top: 24px;
  right: 24px;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: rgba(233, 30, 99, 0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent);
  font-size: 14px;
  opacity: 0;
  transform: translateX(10px);
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.related-article-card:hover .related-article-arrow {
  opacity: 1;
  transform: translateX(0);
}

@media (max-width: 768px) {
  .related-article-card {
    padding: 20px;
  }
  
  .related-article-arrow {
    top: 20px;
    right: 20px;
    width: 28px;
    height: 28px;
    font-size: 12px;
  }
  
  .related-article-card h3 {
    font-size: 1rem;
    margin-right: 40px;
  }
}

/* Grid utility for single column */
.grid-1 {
  grid-template-columns: 1fr;
  max-width: 600px;
  margin: 0 auto;
  transition: .2s;
  height: 100%;
}

@media (max-width: 768px) {
  .category-card {
    padding: 16px;
  }
}

.category-card:hover {
  transform: translateY(-2px);
  border-color: #2a3a55;
}

.category-icon {
  width: 36px;
  height: 36px;
  border-radius: 9px;
  background: rgba(255, 255, 255, .06);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 6px;
  flex-shrink: 0;
}

@media (max-width: 480px) {
  .category-icon {
    width: 32px;
    height: 32px;
  }
}

/* Featured Section */
.featured-section {
  background: linear-gradient(180deg, rgba(255, 255, 255, .02), transparent);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 20px;
  margin-top: 24px;
}

@media (max-width: 768px) {
  .featured-section {
    padding: 16px;
    border-radius: 14px;
  }
}

.featured-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 12px;
}

.featured-icon {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  background: var(--gradient-brand);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  flex-shrink: 0;
}

.featured-card {
  background: rgba(255, 255, 255, .02);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 18px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.featured-card-icon {
  width: 36px;
  height: 36px;
  border-radius: 9px;
  background: rgba(255, 255, 255, .06);
  display: flex;
  align-items: center;
  justify-content: center;
}

.featured-meta {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--text-secondary);
  font-size: .9rem;
  flex-wrap: wrap;
}

.featured-tag {
  padding: 4px 8px;
  border-radius: 999px;
  border: 1px solid var(--border);
  font-size: 0.8rem;
  white-space: nowrap;
}

.featured-tag.trending {
  background: rgba(233, 30, 99, .15);
  border-color: #ad1457;
}

.featured-tag.hot {
  background: rgba(255, 92, 92, .12);
  border-color: #a83a3a;
}

.featured-tag.new {
  background: rgba(156, 39, 176, .15);
  border-color: #7b1fa2;
}

/* Knowledge Cards */
.knowledge-card {
  background: rgba(255, 255, 255, .02);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 18px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.knowledge-icon {
  width: 36px;
  height: 36px;
  border-radius: 9px;
  background: rgba(255, 255, 255, .06);
  display: flex;
  align-items: center;
  justify-content: center;
}

.knowledge-progress {
  display: flex;
  align-items: center;
  gap: 12px;
}

.progress-bar {
  flex: 1;
  height: 6px;
  border-radius: 999px;
  background: #1b2636;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  border-radius: 999px;
  background: linear-gradient(90deg, #e91e63, #9c27b0);
}

.progress-fill.advanced {
  background: linear-gradient(90deg, #9c27b0, #e91e63);
}

.progress-fill.critical {
  background: linear-gradient(90deg, #ff6b6b, #ffd166);
}

.progress-fill.expert {
  background: linear-gradient(90deg, #ffd166, #e91e63);
}

/* General Card Styles */
.card {
  transition: transform .2s ease, border-color .2s ease;
}

.card:hover {
  transform: translateY(-3px);
  border-color: #2a3a55;
}

/* New Header Structure */
.nav .container {
  display: flex;
  flex-direction: column;
  gap: 16px;
  padding: 16px 0;
}

.nav-brand-section {
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 8px 0;
}

.nav-links-section {
  display: flex;
  justify-content: center;
  align-items: center;
}

.nav-search-section {
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 8px 0;
}

.search-container {
  position: relative;
  width: 100%;
  max-width: 400px;
}

.search-box {
  position: relative;
  display: flex;
  align-items: center;
  background: rgba(255, 255, 255, .05);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 0 16px;
  transition: all 0.3s ease;
  backdrop-filter: blur(8px);
}

.search-box:focus-within {
  background: rgba(255, 255, 255, .08);
  border-color: rgba(233, 30, 99, .5);
  box-shadow: 0 0 0 3px rgba(233, 30, 99, .1);
}

.search-icon {
  color: var(--text-secondary);
  margin-right: 12px;
  font-size: 0.9rem;
}

#search-input {
  flex: 1;
  background: transparent;
  border: none;
  outline: none;
  color: var(--text);
  font-size: 0.9rem;
  padding: 12px 0;
  font-family: inherit;
}

#search-input::placeholder {
  color: var(--text-secondary);
}

.search-clear {
  background: none;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  padding: 4px;
  border-radius: 4px;
  transition: all 0.2s ease;
  margin-left: 8px;
}

.search-clear:hover {
  color: var(--text);
  background: rgba(255, 255, 255, .1);
}

.search-dropdown {
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 12px;
  margin-top: 8px;
  max-height: 400px;
  overflow-y: auto;
  z-index: 1000;
  box-shadow: 0 8px 32px rgba(0, 0, 0, .3);
  backdrop-filter: blur(16px);
}

.search-section {
  padding: 12px 0;
}

.search-section:not(:last-child) {
  border-bottom: 1px solid var(--border);
}

.search-section-title {
  padding: 8px 16px;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.search-result {
  display: flex;
  align-items: center;
  padding: 12px 16px;
  cursor: pointer;
  transition: all 0.2s ease;
  text-decoration: none;
  color: var(--text);
}

.search-result:hover {
  background: rgba(255, 255, 255, .05);
  color: var(--text);
}

.search-result-icon {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  background: rgba(255, 255, 255, .1);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-right: 12px;
  font-size: 0.8rem;
  flex-shrink: 0;
}

.search-result-content {
  flex: 1;
  min-width: 0;
}

.search-result-title {
  font-weight: 500;
  margin-bottom: 2px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.search-result-description {
  font-size: 0.8rem;
  color: var(--text-secondary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.search-result-category {
  font-size: 0.7rem;
  color: var(--text-secondary);
  background: rgba(255, 255, 255, .05);
  padding: 2px 6px;
  border-radius: 4px;
  margin-left: 8px;
  flex-shrink: 0;
}

.search-no-results {
  padding: 24px 16px;
  text-align: center;
  color: var(--text-secondary);
  font-size: 0.9rem;
}

/* Responsive Header */
@media (max-width: 1024px) {
  .nav .container {
    gap: 12px;
  }
  
  .nav-brand-section {
    padding: 6px 0;
  }
  
  .nav-search-section {
    padding: 6px 0;
  }
  
  .search-container {
    max-width: none;
    width: 100%;
  }
}

@media (max-width: 768px) {
  .nav .container {
    gap: 10px;
    padding: 12px 0;
  }
  
  .nav-brand-section {
    padding: 4px 0;
  }
  
  .nav-search-section {
    padding: 4px 0;
  }
  
  .nav-links {
    flex-wrap: wrap;
    justify-content: center;
    gap: 4px;
  }
  
  .nav a {
    padding: 8px 12px;
    font-size: 0.9rem;
  }
  
  .search-box {
    padding: 0 12px;
  }
  
  #search-input {
    padding: 10px 0;
    font-size: 0.85rem;
  }
  
  .search-dropdown {
    max-height: 300px;
  }
}

@media (max-width: 480px) {
  .nav .container {
    gap: 8px;
    padding: 10px 0;
  }
  
  .nav-brand-section {
    padding: 2px 0;
  }
  
  .nav-search-section {
    padding: 2px 0;
  }
  
  .brand {
    gap: 8px;
  }
  
  .brand .logo {
    width: 36px;
    height: 36px;
  }
  
  .brand span {
    font-size: 1rem;
  }
  
  .nav-links {
    gap: 2px;
  }
  
  .nav a {
    padding: 6px 10px;
    font-size: 0.85rem;
  }
  
  .search-container {
    max-width: 100%;
  }
  
  .search-box {
    padding: 0 10px;
  }
  
  #search-input {
    padding: 8px 0;
    font-size: 0.8rem;
  }
}

/* Footer */
footer {
  border-top: 1px solid var(--border);
  padding: 40px 0;
  margin-top: 40px;
  background: var(--bg-secondary);
}

@media (max-width: 768px) {
  footer {
    padding: 32px 0;
  }
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 24px;
}

@media (max-width: 768px) {
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }
}

/* Newsletter */
.newsletter {
  background: rgba(255, 255, 255, .03);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 16px;
  display: flex;
  gap: 8px;
}

@media (max-width: 480px) {
  .newsletter {
    flex-direction: column;
    gap: 12px;
  }
}

.newsletter input {
  flex: 1;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 12px;
  color: var(--text);
  font-size: 0.9rem;
}

@media (max-width: 480px) {
  .newsletter input {
    width: 100%;
  }
}

.newsletter button {
  background: var(--gradient-brand);
  border: none;
  border-radius: 10px;
  padding: 12px 16px;
  color: #fff;
  cursor: pointer;
  font-size: 0.9rem;
  white-space: nowrap;
}

@media (max-width: 480px) {
  .newsletter button {
    width: 100%;
  }
}.nav{position:sticky;top:0;z-index:100;background:var(--nav-bg);backdrop-filter:blur(16px);border-bottom:1px solid var(--nav-border);box-shadow:var(--shadow);transition:all 0.3s cubic-bezier(0.4,0,0.2,1)}.nav:hover{background:var(--card);box-shadow:var(--shadow)}.nav .inner{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:16px 0;position:relative}.nav .inner::before{content:'';position:absolute;top:0;left:-5%;right:-5%;height:1px;background:linear-gradient(90deg,transparent,rgba(233,30,99,.6),rgba(156,39,176,.6),transparent);opacity:0;transition:opacity 0.3s ease}.nav:hover .inner::before{opacity:1}.brand{display:flex;align-items:center;gap:12px;font-weight:700;position:relative;transition:transform 0.3s cubic-bezier(0.4,0,0.2,1)}.brand:hover{transform:translateY(-1px)}.brand .logo{width:40px;height:40px;border-radius:12px;background:var(--gradient-brand);display:flex;align-items:center;justify-content:center;color:#fff;position:relative;overflow:hidden;transition:all 0.3s cubic-bezier(0.4,0,0.2,1);box-shadow:0 4px 16px rgba(233,30,99,.25),inset 0 1px 0 rgba(255,255,255,.1)}.brand .logo::before{content:'';position:absolute;top:-50%;left:-50%;width:200%;height:200%;background:linear-gradient(45deg,transparent,rgba(255,255,255,.1),transparent);transform:rotate(45deg);transition:transform 0.6s ease;opacity:0}.brand .logo:hover::before{transform:rotate(45deg) translate(50%,50%);opacity:1}.brand .logo:hover{transform:scale(1.05);box-shadow:0 6px 24px rgba(233,30,99,.4),inset 0 1px 0 rgba(255,255,255,.2)}.brand span{background:linear-gradient(135deg,var(--text) 0%,rgba(233,30,99,.8) 100%);-webkit-background-clip:text;background-clip:text;color:transparent;font-size:1.1rem;letter-spacing:-0.02em}.nav-links{display:flex;align-items:center;justify-content:center;gap:8px;flex-wrap:wrap}.nav a{color:var(--text-secondary);padding:10px 16px;border-radius:10px;font-weight:500;font-size:0.95rem;position:relative;transition:all 0.3s cubic-bezier(0.4,0,0.2,1);overflow:hidden}.nav a::before{content:'';position:absolute;top:0;left:0;right:0;bottom:0;background:linear-gradient(135deg,rgba(233,30,99,.1),rgba(156,39,176,.1));border-radius:10px;opacity:0;transition:opacity 0.3s ease;z-index:-1}.nav a::after{content:'';position:absolute;bottom:0;left:50%;width:0;height:2px;background:var(--gradient-brand);transition:all 0.3s cubic-bezier(0.4,0,0.2,1);transform:translateX(-50%)}.nav a:hover{color:var(--text);transform:translateY(-1px)}.nav a:hover::before{opacity:1}.nav a:hover::after{width:80%}
.nav a[aria-current="page"]{color:var(--text);}
.nav a[aria-current="page"]::before{opacity:1;}
.nav a[aria-current="page"]::after{width:80%;}

/* Navigation layout updates for theme toggle */
.nav-brand-section {
  display: flex;
  justify-content: center;
  margin-bottom: 16px;
}

.nav-links-section {
  display: flex;
  justify-content: center;
  margin-bottom: 16px;
}

.nav-search-section {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 20px;
  flex-wrap: wrap;
}

.theme-toggle-container {
  display: flex;
  align-items: center;
}

@media (max-width: 768px) {
  .nav-search-section {
    flex-direction: column;
    gap: 12px;
  }
  
  .theme-toggle-container {
    order: -1;
  }
}