/* ==========================================================================
   FlyingBird 飞鸟加速器 - Modern Responsive Styling System
   ========================================================================== */

:root {
  --primary-color: #0076ff;
  --primary-gradient: linear-gradient(135deg, #0084ff 0%, #00c6ff 100%);
  --accent-gradient: linear-gradient(135deg, #ff4b8b 0%, #ff8c42 100%);
  --dark-color: #0f172a;
  --text-primary: #1e293b;
  --text-secondary: #64748b;
  --bg-light: #f8fafc;
  --bg-white: #ffffff;
  --card-shadow: 0 10px 30px rgba(0, 118, 255, 0.08);
  --card-shadow-hover: 0 20px 40px rgba(0, 118, 255, 0.16);
  --border-color: #e2e8f0;
  --radius-lg: 16px;
  --radius-md: 12px;
  --radius-sm: 8px;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  color: var(--text-primary);
  background-color: var(--bg-white);
  line-height: 1.6;
}

body {
  overflow-x: hidden;
  position: relative;
}

a {
  text-decoration: none;
  color: inherit;
  transition: var(--transition);
}

/* ==========================================================================
   Navigation Bar
   ========================================================================== */
.header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(226, 232, 240, 0.8);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.03);
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo-brand {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  cursor: pointer;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--dark-color);
}

.logo-img {
  width: 36px;
  height: 36px;
  object-fit: contain;
  transition: var(--transition);
}

.logo-brand:hover .logo-img {
  transform: rotate(-8deg) scale(1.08);
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 2rem;
  list-style: none;
}

.nav-link {
  font-weight: 500;
  font-size: 0.95rem;
  color: var(--text-secondary);
}

.nav-link:hover {
  color: var(--primary-color);
}

.nav-btn {
  background: var(--primary-gradient);
  color: white !important;
  padding: 0.6rem 1.4rem;
  border-radius: 30px;
  font-weight: 600;
  box-shadow: 0 4px 14px rgba(0, 132, 255, 0.3);
}

.nav-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0, 132, 255, 0.4);
}

/* Mobile Nav Toggle */
.mobile-toggle {
  display: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--text-primary);
}

/* ==========================================================================
   Hero Section
   ========================================================================== */
.hero-section {
  padding: 5rem 1.5rem;
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: center;
}

.hero-content h1 {
  font-size: 2.8rem;
  font-weight: 800;
  line-height: 1.25;
  margin-bottom: 1.2rem;
  color: var(--dark-color);
}

.hero-content h1 span {
  background: var(--primary-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-subtitle {
  font-size: 1.15rem;
  color: var(--text-secondary);
  margin-bottom: 2rem;
  line-height: 1.7;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 2.5rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.85rem 1.8rem;
  border-radius: 30px;
  font-weight: 600;
  font-size: 1rem;
  cursor: pointer;
  transition: var(--transition);
  border: none;
}

.btn-primary {
  background: var(--primary-gradient);
  color: white;
  box-shadow: 0 8px 24px rgba(0, 132, 255, 0.35);
}

.btn-primary:hover {
  transform: translateY(-3px);
  box-shadow: 0 12px 30px rgba(0, 132, 255, 0.45);
}

.btn-recommend {
  background: var(--accent-gradient);
  color: white;
  box-shadow: 0 8px 24px rgba(255, 75, 139, 0.3);
}

.btn-recommend:hover {
  transform: translateY(-3px);
  box-shadow: 0 12px 30px rgba(255, 75, 139, 0.4);
}

.btn-outline {
  background: transparent;
  color: var(--primary-color);
  border: 2px solid #0084ff;
}

.btn-outline:hover {
  background: rgba(0, 132, 255, 0.06);
  transform: translateY(-3px);
}

.hero-badges {
  display: flex;
  gap: 1.5rem;
  flex-wrap: wrap;
}

.badge-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.9rem;
  color: var(--text-secondary);
  font-weight: 500;
}

.badge-item svg {
  color: var(--primary-color);
}

/* Dynamic Graphic Card */
.hero-visual {
  position: relative;
  display: flex;
  justify-content: center;
}

.visual-card-wrapper {
  position: relative;
  width: 100%;
  max-width: 500px;
  background: linear-gradient(145deg, #ffffff, #f0f7ff);
  border-radius: 24px;
  padding: 2.5rem;
  border: 1px solid rgba(0, 132, 255, 0.15);
  box-shadow: var(--card-shadow);
}

.visual-floating-badge {
  position: absolute;
  background: white;
  padding: 0.8rem 1.2rem;
  border-radius: 50px;
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-weight: 600;
  font-size: 0.9rem;
  animation: float 4s ease-in-out infinite;
}

.badge-1 {
  top: -20px;
  right: -10px;
}

.badge-2 {
  bottom: -20px;
  left: -10px;
  animation-delay: 2s;
}

@keyframes float {
  0%, 100% { transform: translateY(0px); }
  50% { transform: translateY(-10px); }
}

/* ==========================================================================
   Section Titles
   ========================================================================== */
.section {
  padding: 5rem 1.5rem;
  max-width: 1200px;
  margin: 0 auto;
}

.section-bg {
  background-color: var(--bg-light);
  border-radius: 24px;
  margin-top: 2rem;
  margin-bottom: 2rem;
}

.section-title {
  text-align: center;
  font-size: 2.2rem;
  font-weight: 800;
  color: var(--dark-color);
  margin-bottom: 0.8rem;
}

.section-subtitle {
  text-align: center;
  font-size: 1.05rem;
  color: var(--text-secondary);
  max-width: 650px;
  margin: 0 auto 3.5rem auto;
}

/* ==========================================================================
   Core Advantages (3 Feature Cards)
   ========================================================================== */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.feature-card {
  background: white;
  border-radius: var(--radius-lg);
  padding: 2.5rem 1.8rem;
  border: 1px solid var(--border-color);
  box-shadow: var(--card-shadow);
  transition: var(--transition);
  text-align: center;
}

.feature-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--card-shadow-hover);
  border-color: rgba(0, 132, 255, 0.3);
}

.feature-icon-wrapper {
  width: 70px;
  height: 70px;
  margin: 0 auto 1.5rem auto;
  border-radius: 20px;
  background: rgba(0, 132, 255, 0.08);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--primary-color);
}

.feature-card h3 {
  font-size: 1.3rem;
  margin-bottom: 0.8rem;
  color: var(--dark-color);
}

.feature-card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.6;
}

/* ==========================================================================
   Streaming & AI Support Section
   ========================================================================== */
.streaming-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.5rem;
}

.stream-card {
  background: white;
  padding: 1.5rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  gap: 1rem;
  transition: var(--transition);
}

.stream-card:hover {
  transform: scale(1.03);
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.06);
  border-color: var(--primary-color);
}

.stream-logo {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1.2rem;
  color: white;
}

.bg-netflix { background: #e50914; }
.bg-youtube { background: #ff0000; }
.bg-openai { background: #10a37f; }
.bg-disney { background: #113ccf; }
.bg-claude { background: #d97706; }
.bg-midjourney { background: #5865f2; }
.bg-tiktok { background: #000000; }
.bg-spotify { background: #1ed760; }

.stream-info h4 {
  font-size: 1.05rem;
  color: var(--dark-color);
}

.stream-info p {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

/* ==========================================================================
   Pricing Table
   ========================================================================== */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
  align-items: stretch;
}

.price-card {
  background: white;
  border-radius: var(--radius-lg);
  padding: 2.2rem 1.5rem;
  border: 1px solid var(--border-color);
  box-shadow: var(--card-shadow);
  display: flex;
  flex-direction: column;
  position: relative;
  transition: var(--transition);
}

.price-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--card-shadow-hover);
}

.price-card.popular {
  border: 2px solid var(--primary-color);
  background: linear-gradient(180deg, #ffffff 0%, #f0f7ff 100%);
}

.popular-tag {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--primary-gradient);
  color: white;
  padding: 0.3rem 1.2rem;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.5px;
}

.price-header {
  text-align: center;
  margin-bottom: 1.5rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--border-color);
}

.price-name {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--dark-color);
  margin-bottom: 0.5rem;
}

.price-amount {
  font-size: 2.2rem;
  font-weight: 800;
  color: var(--primary-color);
}

.price-amount span {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-secondary);
}

.price-features {
  list-style: none;
  margin-bottom: 2rem;
  flex-grow: 1;
}

.price-features li {
  margin-bottom: 0.8rem;
  font-size: 0.9rem;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.price-features li svg {
  color: #10b981;
  flex-shrink: 0;
}

.price-card .btn {
  width: 100%;
}

/* ==========================================================================
   SEO Articles Grid Section
   ========================================================================== */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.8rem;
}

.article-card {
  background: white;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  padding: 1.5rem;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.04);
  transition: var(--transition);
  display: flex;
  flex-direction: column;
}

.article-card:hover {
  transform: translateY(-5px);
  border-color: var(--primary-color);
  box-shadow: var(--card-shadow);
}

.article-tag {
  display: inline-block;
  background: rgba(0, 132, 255, 0.1);
  color: var(--primary-color);
  padding: 0.25rem 0.75rem;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 600;
  margin-bottom: 0.8rem;
  width: fit-content;
}

.article-card h3 {
  font-size: 1.1rem;
  line-height: 1.4;
  margin-bottom: 0.8rem;
  color: var(--dark-color);
}

.article-card p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 1.2rem;
  flex-grow: 1;
}

.article-readmore {
  color: var(--primary-color);
  font-weight: 600;
  font-size: 0.9rem;
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
}

.article-readmore:hover {
  gap: 0.6rem;
}

/* ==========================================================================
   FAQ Section Accordion
   ========================================================================== */
.faq-list {
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.faq-item {
  background: white;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.faq-question {
  width: 100%;
  padding: 1.2rem 1.5rem;
  text-align: left;
  background: white;
  border: none;
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--dark-color);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.faq-answer {
  padding: 0 1.5rem 1.2rem 1.5rem;
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.6;
  display: none;
}

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

.faq-item.active .faq-question {
  color: var(--primary-color);
}

/* ==========================================================================
   User Testimonials
   ========================================================================== */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.8rem;
}

.review-card {
  background: white;
  padding: 1.8rem;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.03);
}

.review-stars {
  color: #f59e0b;
  margin-bottom: 0.8rem;
}

.review-text {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 1.2rem;
  font-style: italic;
}

.review-author {
  display: flex;
  align-items: center;
  gap: 0.8rem;
}

.author-avatar {
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: var(--primary-gradient);
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
}

.author-info h4 {
  font-size: 0.95rem;
  color: var(--dark-color);
}

.author-info p {
  font-size: 0.8rem;
  color: var(--text-secondary);
}

/* ==========================================================================
   Footer
   ========================================================================== */
.footer {
  background: #0b1120;
  color: #94a3b8;
  padding: 4rem 1.5rem 2rem 1.5rem;
}

.footer-container {
  max-width: 1200px;
  margin: 0 auto;
}

.footer-nav-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 2rem;
  margin-bottom: 3rem;
  padding-bottom: 3rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-col h4 {
  color: white;
  font-size: 1.1rem;
  margin-bottom: 1.2rem;

}

.footer-col ul {
  list-style: none;
}

.footer-col ul li {
  margin-bottom: 0.6rem;
}

.footer-col ul li a {
  color: #94a3b8;
  font-size: 0.95rem;
}

.footer-col ul li a:hover {
  color: white;
}

.footer-pbn-section {
  text-align: center;
  padding: 1.5rem 0;
  font-size: 0.9rem;
  color: #64748b;
  line-height: 1.8;
}

.footer-pbn-links {
  margin-top: 0.8rem;
  display: flex;
  justify-content: center;
  gap: 2rem;
  flex-wrap: wrap;
}

.footer-pbn-links a {
  color: #38bdf8;
  font-weight: 600;
  text-decoration: underline;
}

.footer-pbn-links a:hover {
  color: #7dd3fc;
}

/* ==========================================================================
   Right Side Arrow Navigation Widget
   ========================================================================== */
.side-nav-widget {
  position: fixed;
  right: 25px;
  top: 50%;
  transform: translateY(-50%);
  z-index: 9999;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.side-arrow-btn {
  width: 44px;
  height: 44px;
  background: white;
  border-radius: 50%;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.15);
  border: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--dark-color);
  transition: var(--transition);
}

.side-arrow-btn:hover {
  background: var(--primary-color);
  color: white;
  transform: scale(1.1);
  box-shadow: 0 6px 20px rgba(0, 132, 255, 0.4);
}

/* ==========================================================================
   Responsive Design (@media)
   ========================================================================== */
@media (max-width: 992px) {
  .hero-section {
    grid-template-columns: 1fr;
    text-align: center;
  }
  .hero-actions, .hero-badges {
    justify-content: center;
  }
  .features-grid, .pricing-grid, .articles-grid, .reviews-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .footer-nav-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .nav-menu {
    display: none;
  }
  .hero-content h1 {
    font-size: 2.1rem;
  }
  .features-grid, .pricing-grid, .articles-grid, .reviews-grid {
    grid-template-columns: 1fr;
  }
  .footer-nav-grid {
    grid-template-columns: 1fr;
  }
  .side-nav-widget {
    right: 12px;
  }
  .btn {
    width: 100%;
  }
}