/* CSS Design System & Theme Styles */
@import url('https://fonts.googleapis.com/css2?family=Kaiti+SC&family=Noto+Serif+SC:wght@400;600;700&family=Orbitron:wght@500;700;900&family=Plus+Jakarta+Sans:wght@400;500;600;700&display=swap');

:root {
  --bg-gradient: linear-gradient(to right, rgb(201, 214, 255), rgb(226, 226, 226));
  --font-kaiti: "STKaiti", "KaiTi", "楷体", "Noto Serif SC", serif;
  --font-orbitron: "Orbitron", sans-serif;
  --font-sans: "Plus Jakarta Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  
  --space-dark: #0a0e1a;
  --space-card: rgba(15, 23, 42, 0.75);
  --space-card-border: rgba(99, 102, 241, 0.2);
  --space-card-hover: rgba(30, 41, 59, 0.85);
  
  --primary-glow: #3b82f6;
  --accent-cyan: #06b6d4;
  --accent-purple: #8b5cf6;
  --accent-pink: #ec4899;
  
  --text-main: #0f172a;
  --text-muted: #475569;
  --text-space-light: #f8fafc;
  --text-space-muted: #94a3b8;
  
  --radius-lg: 16px;
  --radius-md: 10px;
  --radius-sm: 6px;
  
  --shadow-space: 0 10px 30px -10px rgba(0, 0, 0, 0.5), 0 0 15px rgba(59, 130, 246, 0.2);
  --shadow-hover: 0 20px 40px -15px rgba(0, 0, 0, 0.7), 0 0 25px rgba(139, 92, 246, 0.4);
}

/* Global Reset & Base */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  font-family: var(--font-kaiti);
}

body {
  background: var(--bg-gradient);
  color: #1e293b;
  min-height: 100vh;
  line-height: 1.8;
  position: relative;
  overflow-x: hidden;
  font-size: 17px;
}

/* Dynamic Canvas & Cosmic Decorator Background */
#cosmic-canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  pointer-events: none;
  z-index: 0;
  opacity: 0.65;
}

.app-wrapper {
  position: relative;
  z-index: 1;
}

/* Typography Utility */
.kaiti-font {
  font-family: var(--font-kaiti) !important;
}

.orbitron-font {
  font-family: var(--font-orbitron) !important;
}

/* Navigation Bar */
.navbar {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(10, 14, 26, 0.88);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
  transition: all 0.3s ease;
}

.nav-container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0.85rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: #fff;
}

.brand-logo-icon {
  width: 38px;
  height: 38px;
  background: linear-gradient(135deg, var(--accent-cyan), var(--accent-purple));
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 0 15px rgba(6, 182, 212, 0.5);
  animation: pulse-glow 3s infinite ease-in-out;
}

.brand-text {
  font-size: 1.4rem;
  font-weight: 700;
  background: linear-gradient(135deg, #ffffff 0%, #93c5fd 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  letter-spacing: 1px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.8rem;
  list-style: none;
}

.nav-link {
  color: #cbd5e1;
  text-decoration: none;
  font-size: 1.05rem;
  font-weight: 500;
  transition: all 0.25s ease;
  position: relative;
  padding: 4px 0;
}

.nav-link:hover, .nav-link.active {
  color: #38bdf8;
  text-shadow: 0 0 8px rgba(56, 189, 248, 0.4);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0%;
  height: 2px;
  background: linear-gradient(90deg, #38bdf8, #818cf8);
  transition: width 0.3s ease;
  border-radius: 2px;
}

.nav-link:hover::after, .nav-link.active::after {
  width: 100%;
}

.btn-login {
  background: linear-gradient(135deg, #2563eb, #7c3aed);
  color: #ffffff !important;
  padding: 0.6rem 1.4rem;
  border-radius: 30px;
  font-weight: 600;
  text-decoration: none;
  box-shadow: 0 4px 15px rgba(37, 99, 235, 0.4);
  transition: all 0.3s ease;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.btn-login:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 25px rgba(124, 58, 237, 0.6);
  background: linear-gradient(135deg, #1d4ed8, #6d28d9);
}

/* Mobile Menu Toggle */
.mobile-toggle {
  display: none;
  background: none;
  border: none;
  color: #fff;
  font-size: 1.5rem;
  cursor: pointer;
}

/* Containers & Sections */
.container {
  max-width: 1240px;
  margin: 0 auto;
  padding: 2.5rem 1.5rem;
}

.section-header {
  text-align: center;
  margin-bottom: 3.5rem;
}

.section-title {
  font-size: 2.3rem;
  font-weight: 700;
  color: #0f172a;
  margin-bottom: 0.8rem;
  position: relative;
  display: inline-block;
}

.section-subtitle {
  color: #475569;
  font-size: 1.15rem;
  max-width: 650px;
  margin: 0 auto;
}

/* Glass Dark Card Component */
.glass-dark-card {
  background: rgba(15, 23, 42, 0.88);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: var(--radius-lg);
  padding: 2rem;
  color: #f8fafc;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
  transition: all 0.35s ease;
}

.glass-dark-card:hover {
  border-color: rgba(56, 189, 248, 0.4);
  box-shadow: 0 15px 35px rgba(0, 0, 0, 0.35), 0 0 20px rgba(56, 189, 248, 0.2);
  transform: translateY(-4px);
}

/* Hero Section */
.hero-section {
  padding: 4rem 1.5rem 3rem;
  text-align: center;
  max-width: 1100px;
  margin: 0 auto;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(15, 23, 42, 0.85);
  color: #38bdf8;
  border: 1px solid rgba(56, 189, 248, 0.3);
  padding: 6px 18px;
  border-radius: 50px;
  font-size: 0.95rem;
  margin-bottom: 1.5rem;
  box-shadow: 0 0 15px rgba(56, 189, 248, 0.15);
}

.hero-title {
  font-size: 3.2rem;
  line-height: 1.25;
  font-weight: 700;
  color: #0f172a;
  margin-bottom: 1.2rem;
  letter-spacing: -0.5px;
}

.hero-title span {
  background: linear-gradient(135deg, #1e40af, #6d28d9);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-description {
  font-size: 1.25rem;
  color: #334155;
  max-width: 800px;
  margin: 0 auto 2.5rem;
  line-height: 1.8;
}

.hero-actions {
  display: flex;
  justify-content: center;
  gap: 1.2rem;
  flex-wrap: wrap;
}

.btn-primary-lg {
  background: linear-gradient(135deg, #2563eb, #7c3aed);
  color: #ffffff;
  padding: 0.9rem 2.2rem;
  border-radius: 40px;
  font-size: 1.15rem;
  font-weight: 600;
  text-decoration: none;
  box-shadow: 0 10px 25px rgba(37, 99, 235, 0.4);
  transition: all 0.3s ease;
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.btn-primary-lg:hover {
  transform: translateY(-3px) scale(1.02);
  box-shadow: 0 15px 35px rgba(124, 58, 237, 0.5);
}

.btn-secondary-lg {
  background: rgba(15, 23, 42, 0.9);
  color: #f8fafc;
  padding: 0.9rem 2.2rem;
  border-radius: 40px;
  font-size: 1.15rem;
  font-weight: 600;
  text-decoration: none;
  border: 1px solid rgba(255, 255, 255, 0.15);
  transition: all 0.3s ease;
}

.btn-secondary-lg:hover {
  background: rgba(30, 41, 59, 0.95);
  border-color: #38bdf8;
  color: #38bdf8;
  transform: translateY(-3px);
}

/* Features Grid */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.8rem;
  margin-top: 1rem;
}

.feature-icon {
  width: 54px;
  height: 54px;
  border-radius: 12px;
  background: linear-gradient(135deg, rgba(56, 189, 248, 0.2), rgba(139, 92, 246, 0.2));
  border: 1px solid rgba(56, 189, 248, 0.3);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  color: #38bdf8;
  margin-bottom: 1.2rem;
}

.feature-title {
  font-size: 1.35rem;
  font-weight: 700;
  margin-bottom: 0.6rem;
  color: #f8fafc;
}

.feature-desc {
  color: #94a3b8;
  font-size: 1rem;
  line-height: 1.7;
}

/* Pricing Grid (Strictly Based on Image 1) */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.8rem;
  margin-top: 2rem;
}

@media (max-width: 992px) {
  .pricing-grid {
    grid-template-columns: 1fr;
    max-width: 450px;
    margin-left: auto;
    margin-right: auto;
  }
}

.pricing-card {
  background: #191b1f; /* Dark matching image 1 */
  border-radius: 8px;
  border: 1px solid #2d3139;
  padding: 2rem 1.8rem;
  position: relative;
  overflow: hidden;
  color: #e2e8f0;
  display: flex;
  flex-direction: column;
}

.pricing-card.featured {
  border: 1px solid #7c3aed;
  box-shadow: 0 0 25px rgba(124, 58, 237, 0.25);
}

.pricing-badge {
  position: absolute;
  top: 18px;
  right: -32px;
  background: #d946ef;
  color: #fff;
  padding: 4px 35px;
  transform: rotate(45deg);
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 1px;
}

.pricing-name {
  font-size: 1.4rem;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 1.2rem;
}

.pricing-price-box {
  margin-bottom: 1.2rem;
}

.pricing-price {
  font-size: 2.2rem;
  font-weight: 800;
  color: #ef4444; /* Bright Red as in image 1 */
}

.pricing-period {
  font-size: 0.9rem;
  color: #94a3b8;
}

.btn-buy {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  width: 100%;
  background: #7f1d1d; /* Dark Red button background from Image 1 */
  border: 1px solid #991b1b;
  color: #ffffff;
  padding: 0.7rem;
  border-radius: 6px;
  font-weight: 600;
  text-decoration: none;
  font-size: 1.05rem;
  margin-bottom: 1.8rem;
  transition: all 0.25s ease;
}

.btn-buy:hover {
  background: #991b1b;
  box-shadow: 0 4px 15px rgba(239, 68, 68, 0.4);
}

.pricing-section-label {
  font-size: 0.95rem;
  font-weight: 700;
  color: #ffffff;
  margin-top: 0.8rem;
  margin-bottom: 0.4rem;
  display: flex;
  align-items: center;
  gap: 8px;
}

.pricing-tag {
  background: #991b1b;
  color: #ffffff;
  font-size: 0.72rem;
  padding: 2px 8px;
  border-radius: 12px;
  font-weight: 500;
}

.pricing-feature-list {
  list-style: none;
  margin-bottom: 0.6rem;
}

.pricing-feature-item {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  font-size: 0.95rem;
  color: #cbd5e1;
  margin-bottom: 0.4rem;
}

.pricing-feature-item i {
  color: #22c55e;
  margin-top: 4px;
  font-size: 0.9rem;
}

/* Articles Grid Section */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
  gap: 1.8rem;
}

.article-card {
  display: flex;
  flex-direction: column;
  height: 100%;
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 0.85rem;
  color: #38bdf8;
  margin-bottom: 0.8rem;
}

.article-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 0.8rem;
  line-height: 1.4;
}

.article-excerpt {
  color: #94a3b8;
  font-size: 0.98rem;
  line-height: 1.7;
  flex-grow: 1;
  margin-bottom: 1.2rem;
}

.article-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding-top: 1rem;
  font-size: 0.85rem;
  color: #64748b;
}

.read-more-link {
  color: #38bdf8;
  text-decoration: none;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  transition: gap 0.2s ease;
}

.read-more-link:hover {
  gap: 8px;
  color: #60a5fa;
}

/* Tag Cloud Section */
.tag-cloud-box {
  background: rgba(15, 23, 42, 0.9);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-lg);
  padding: 2rem;
  margin-top: 3rem;
  text-align: center;
}

.tag-cloud-title {
  color: #f8fafc;
  font-size: 1.3rem;
  margin-bottom: 1.2rem;
}

.tags-wrapper {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.7rem;
}

.seo-tag {
  background: rgba(30, 41, 59, 0.8);
  color: #cbd5e1;
  padding: 6px 14px;
  border-radius: 20px;
  font-size: 0.9rem;
  border: 1px solid rgba(255, 255, 255, 0.08);
  text-decoration: none;
  transition: all 0.25s ease;
}

.seo-tag:hover {
  background: rgba(56, 189, 248, 0.15);
  color: #38bdf8;
  border-color: rgba(56, 189, 248, 0.3);
  transform: translateY(-2px);
}

/* FAQ Accordion Component */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  max-width: 900px;
  margin: 0 auto;
}

.faq-item {
  background: rgba(15, 23, 42, 0.88);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: all 0.3s ease;
}

.faq-question {
  padding: 1.2rem 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  font-weight: 700;
  font-size: 1.1rem;
  color: #f8fafc;
}

.faq-question i {
  transition: transform 0.3s ease;
  color: #38bdf8;
}

.faq-item.active .faq-question i {
  transform: rotate(180deg);
}

.faq-answer {
  padding: 0 1.5rem 1.2rem;
  color: #cbd5e1;
  font-size: 1rem;
  line-height: 1.8;
  display: none;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  margin-top: 0.5rem;
  padding-top: 1rem;
}

.faq-item.active .faq-answer {
  display: block;
}

/* Footer Section */
.footer {
  background: #070a12;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  color: #94a3b8;
  padding: 4rem 1.5rem 2rem;
  margin-top: 4rem;
}

.footer-container {
  max-width: 1240px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 2.5rem;
  margin-bottom: 3rem;
}

.footer-brand-desc {
  margin-top: 1rem;
  font-size: 0.95rem;
  line-height: 1.7;
}

.footer-column-title {
  color: #f8fafc;
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 1.2rem;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.7rem;
}

.footer-link {
  color: #94a3b8;
  text-decoration: none;
  font-size: 0.95rem;
  transition: color 0.2s ease;
}

.footer-link:hover {
  color: #38bdf8;
}

.footer-bottom {
  max-width: 1240px;
  margin: 0 auto;
  padding-top: 2rem;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  font-size: 0.9rem;
}

/* Keyframes */
@keyframes pulse-glow {
  0%, 100% {
    box-shadow: 0 0 15px rgba(6, 182, 212, 0.5);
  }
  50% {
    box-shadow: 0 0 25px rgba(139, 92, 246, 0.8);
  }
}

/* Article Detail Page Layout */
.article-detail-container {
  max-width: 920px;
  margin: 0 auto;
  padding: 2rem 1.5rem 4rem;
}

.article-header {
  margin-bottom: 2.5rem;
  text-align: center;
}

.article-title-main {
  font-size: 2.4rem;
  font-weight: 700;
  color: #0f172a;
  line-height: 1.35;
  margin-bottom: 1.2rem;
}

.article-meta-bar {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1.5rem;
  flex-wrap: wrap;
  font-size: 0.92rem;
  background: rgba(15, 23, 42, 0.85);
  color: #94a3b8;
  padding: 0.8rem 1.5rem;
  border-radius: 30px;
  border: 1px solid rgba(255, 255, 255, 0.1);
  display: inline-flex;
}

.article-meta-bar span {
  display: flex;
  align-items: center;
  gap: 6px;
}

.article-meta-bar span i {
  color: #38bdf8;
}

.article-body-content {
  background: rgba(15, 23, 42, 0.9);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: var(--radius-lg);
  padding: 2.8rem 2.2rem;
  color: #e2e8f0;
  box-shadow: 0 15px 35px rgba(0,0,0,0.3);
  margin-bottom: 3rem;
  font-size: 1.1rem;
  line-height: 2;
}

.article-body-content h2 {
  color: #38bdf8;
  font-size: 1.65rem;
  margin: 2.2rem 0 1rem;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid rgba(56, 189, 248, 0.2);
}

.article-body-content h3 {
  color: #f8fafc;
  font-size: 1.35rem;
  margin: 1.8rem 0 0.8rem;
}

.article-body-content p {
  margin-bottom: 1.4rem;
  text-indent: 2em;
}

.article-body-content ul, .article-body-content ol {
  margin-bottom: 1.4rem;
  padding-left: 2rem;
}

.article-body-content li {
  margin-bottom: 0.5rem;
}

.article-cta-box {
  background: linear-gradient(135deg, rgba(37, 99, 235, 0.2), rgba(124, 58, 237, 0.2));
  border: 1px solid rgba(56, 189, 248, 0.4);
  border-radius: var(--radius-md);
  padding: 1.8rem;
  text-align: center;
  margin: 2.5rem 0;
}

.article-cta-box h4 {
  font-size: 1.4rem;
  color: #fff;
  margin-bottom: 0.6rem;
}

.article-cta-box p {
  text-indent: 0;
  color: #cbd5e1;
  margin-bottom: 1.2rem;
}

.internal-nav-box {
  background: rgba(15, 23, 42, 0.85);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  margin-top: 3rem;
}

.internal-nav-title {
  color: #38bdf8;
  font-size: 1.1rem;
  margin-bottom: 1rem;
  font-weight: 700;
}

.internal-links-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 0.8rem;
}

.internal-link-item {
  color: #cbd5e1;
  text-decoration: none;
  font-size: 0.95rem;
  padding: 8px 12px;
  background: rgba(30, 41, 59, 0.6);
  border-radius: 6px;
  transition: all 0.2s ease;
  display: block;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.internal-link-item:hover {
  background: rgba(56, 189, 248, 0.2);
  color: #38bdf8;
}

/* Responsive adjustments */
@media (max-width: 768px) {
  .nav-links {
    display: none;
  }
  .mobile-toggle {
    display: block;
  }
  .hero-title {
    font-size: 2.2rem;
  }
  .article-title-main {
    font-size: 1.8rem;
  }
  .article-body-content {
    padding: 1.5rem 1.2rem;
    font-size: 1.02rem;
  }
}