/* KFC Airport / 肯德基机场 (kendeji.sbs) CSS */

:root {
  --primary: #E4002B;
  --primary-hover: #C00024;
  --primary-light: #FFF0F2;
  --accent-orange: #FF5A1F;
  --dark: #1D1D1F;
  --dark-gray: #424245;
  --light-gray: #F5F5F7;
  --border-color: #E5E5EA;
  --card-shadow: 0 8px 30px rgba(0, 0, 0, 0.06);
  --card-shadow-hover: 0 14px 40px rgba(228, 0, 43, 0.12);
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}

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

html {
  scroll-behavior: smooth;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--dark);
  background-color: #FAFAFC;
  line-height: 1.6;
}

body {
  overflow-x: hidden;
}

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

img {
  max-width: 100%;
  height: auto;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* Header & Nav */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(0, 0, 0, 0.05);
  height: 72px;
  display: flex;
  align-items: center;
}

.header-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 22px;
  font-weight: 800;
  color: var(--dark);
  letter-spacing: -0.5px;
}

.brand-logo img {
  height: 36px;
  width: 36px;
  object-fit: contain;
}

.brand-name span {
  color: var(--primary);
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-link {
  font-size: 15px;
  font-weight: 500;
  color: var(--dark-gray);
  position: relative;
  padding: 6px 0;
}

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

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--primary);
  transition: var(--transition);
}

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

.header-actions {
  display: flex;
  align-items: center;
  gap: 16px;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, #FF3B30 0%, #E4002B 100%);
  color: #ffffff !important;
  font-weight: 600;
  font-size: 15px;
  padding: 10px 24px;
  border-radius: 30px;
  box-shadow: 0 4px 14px rgba(228, 0, 43, 0.35);
  transition: var(--transition);
  border: none;
  cursor: pointer;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(228, 0, 43, 0.45);
  background: linear-gradient(135deg, #FF4D42 0%, #C00024 100%);
  color: #ffffff !important;
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: #ffffff;
  color: var(--dark);
  font-weight: 600;
  font-size: 15px;
  padding: 10px 24px;
  border-radius: 30px;
  border: 1px solid var(--border-color);
  box-shadow: 0 2px 8px rgba(0,0,0,0.04);
  transition: var(--transition);
}

.btn-secondary:hover {
  border-color: var(--primary);
  color: var(--primary);
  transform: translateY(-2px);
}

.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  font-size: 24px;
  cursor: pointer;
  color: var(--dark);
}

/* Hero Section */
.hero-section {
  padding: 80px 0 60px;
  text-align: center;
  position: relative;
  background: radial-gradient(circle at 50% 0%, rgba(228, 0, 43, 0.05) 0%, rgba(255, 255, 255, 0) 70%);
}

.badge-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--primary-light);
  color: var(--primary);
  padding: 6px 16px;
  border-radius: 20px;
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 24px;
}

.hero-title {
  font-size: 48px;
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -1px;
  margin-bottom: 20px;
  color: var(--dark);
}

.hero-title .highlight {
  background: linear-gradient(135deg, #E4002B, #FF5A1F);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-subtitle {
  font-size: 18px;
  color: var(--dark-gray);
  max-width: 720px;
  margin: 0 auto 36px;
  line-height: 1.7;
}

.hero-cta {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin-bottom: 48px;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  max-width: 900px;
  margin: 0 auto;
}

.stat-card {
  background: #ffffff;
  padding: 20px;
  border-radius: var(--radius-md);
  border: 1px solid rgba(0,0,0,0.06);
  box-shadow: 0 4px 16px rgba(0,0,0,0.03);
}

.stat-number {
  font-size: 28px;
  font-weight: 800;
  color: var(--primary);
  margin-bottom: 4px;
}

.stat-label {
  font-size: 13px;
  color: var(--dark-gray);
}

/* Features Sections */
.section-padding {
  padding: 80px 0;
}

.section-title-wrap {
  text-align: center;
  max-width: 680px;
  margin: 0 auto 56px;
}

.section-title {
  font-size: 36px;
  font-weight: 800;
  margin-bottom: 12px;
  letter-spacing: -0.5px;
}

.section-subtitle {
  font-size: 16px;
  color: var(--dark-gray);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
}

.feature-card {
  background: #ffffff;
  padding: 36px 28px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.feature-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--card-shadow-hover);
  border-color: rgba(228, 0, 43, 0.3);
}

.feature-icon {
  width: 56px;
  height: 56px;
  background: var(--primary-light);
  color: var(--primary);
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 26px;
  margin-bottom: 20px;
}

.feature-card h3 {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 12px;
}

.feature-card p {
  color: var(--dark-gray);
  font-size: 15px;
  line-height: 1.6;
}

/* Pricing Section */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.pricing-card {
  background: #ffffff;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  padding: 32px 24px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: var(--transition);
}

.pricing-card.popular {
  border: 2px solid var(--primary);
  box-shadow: 0 12px 36px rgba(228, 0, 43, 0.15);
  transform: scale(1.03);
}

.popular-badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: linear-gradient(135deg, #FF3B30, #E4002B);
  color: #ffffff;
  font-size: 12px;
  font-weight: 700;
  padding: 4px 14px;
  border-radius: 12px;
  letter-spacing: 0.5px;
}

.pricing-header h3 {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 8px;
}

.pricing-header p {
  font-size: 13px;
  color: var(--dark-gray);
  margin-bottom: 20px;
}

.price-wrap {
  margin-bottom: 24px;
}

.price-wrap .currency {
  font-size: 20px;
  font-weight: 700;
  color: var(--primary);
}

.price-wrap .amount {
  font-size: 42px;
  font-weight: 900;
  color: var(--primary);
  letter-spacing: -1px;
}

.price-wrap .period {
  font-size: 14px;
  color: var(--dark-gray);
}

.pricing-features {
  list-style: none;
  margin-bottom: 32px;
  flex-grow: 1;
}

.pricing-features li {
  font-size: 14px;
  color: var(--dark-gray);
  padding: 8px 0;
  display: flex;
  align-items: center;
  gap: 10px;
}

.pricing-features li i {
  color: #34C759;
  font-weight: bold;
}

/* FAQ Accordion */
.faq-grid {
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

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

.faq-question {
  padding: 20px 24px;
  font-size: 17px;
  font-weight: 700;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  user-select: none;
}

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

.faq-icon {
  font-size: 20px;
  transition: transform 0.3s ease;
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease, padding 0.3s ease;
  padding: 0 24px;
  color: var(--dark-gray);
  font-size: 15px;
  line-height: 1.7;
}

.faq-item.active .faq-answer {
  max-height: 300px;
  padding: 0 24px 20px;
}

.faq-item.active .faq-icon {
  transform: rotate(45deg);
}

/* Testimonials */
.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.testimonial-card {
  background: #ffffff;
  padding: 28px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  box-shadow: var(--card-shadow);
}

.stars {
  color: #FFB800;
  margin-bottom: 12px;
  font-size: 16px;
}

.testimonial-card p {
  font-size: 15px;
  color: var(--dark-gray);
  margin-bottom: 20px;
  line-height: 1.6;
}

.user-info {
  display: flex;
  align-items: center;
  gap: 12px;
}

.user-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--primary-light);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
}

.user-details h4 {
  font-size: 15px;
  font-weight: 700;
}

.user-details span {
  font-size: 12px;
  color: var(--dark-gray);
}

/* Cloud Exploration / Articles Grid Section (Matching User Image) */
.articles-section {
  padding: 90px 0;
  background-color: #FAFAFC;
}

.articles-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
}

.article-card {
  background: #ffffff;
  padding: 32px 36px;
  border-radius: var(--radius-lg);
  border: 1px solid rgba(0, 0, 0, 0.05);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.03);
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.article-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.07);
}

.article-card h3 {
  font-size: 20px;
  font-weight: 800;
  line-height: 1.45;
  color: var(--dark);
  margin-bottom: 14px;
  letter-spacing: -0.3px;
}

.article-card h3 a:hover {
  color: var(--primary);
}

.article-card p {
  font-size: 14px;
  color: #6E6E73;
  line-height: 1.65;
  margin-bottom: 24px;
}

.article-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--primary);
  font-weight: 700;
  font-size: 15px;
}

.article-link:hover {
  gap: 10px;
  color: var(--primary-hover);
}

/* Footer & PBN Area */
.site-footer {
  background: #ffffff;
  border-top: 1px solid var(--border-color);
  padding: 48px 0 32px;
  text-align: center;
}

.footer-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 20px;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 18px;
  font-weight: 700;
}

.footer-brand img {
  height: 28px;
}

.footer-copy {
  font-size: 13px;
  color: #86868B;
}

/* PBN Friend Link Section - Core Task 2 requirement */
.friend-links-wrap {
  margin-top: 16px;
  padding-top: 16px;
  border-top: 1px dashed #E5E5EA;
  font-size: 12px;
  color: #86868B;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
}

.friend-links-title {
  color: #A1A1A6;
  font-weight: 500;
}

.friend-link-item {
  color: #6E6E73;
  text-decoration: none;
  transition: color 0.2s ease;
}

.friend-link-item:hover {
  color: var(--primary);
  text-decoration: underline;
}

/* Single Article Page Layout */
.article-header {
  padding: 60px 0 40px;
  background: #ffffff;
  border-bottom: 1px solid var(--border-color);
}

.breadcrumbs {
  font-size: 14px;
  color: var(--dark-gray);
  margin-bottom: 16px;
}

.breadcrumbs a:hover {
  color: var(--primary);
}

.article-page-title {
  font-size: 38px;
  font-weight: 800;
  line-height: 1.3;
  margin-bottom: 16px;
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 20px;
  font-size: 14px;
  color: #86868B;
}

.article-content-wrap {
  padding: 60px 0;
  background: #ffffff;
}

.article-layout {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 48px;
}

.article-body {
  font-size: 16px;
  line-height: 1.85;
  color: #2D2D2F;
}

.article-body h2 {
  font-size: 26px;
  font-weight: 800;
  margin: 40px 0 16px;
  color: var(--dark);
  padding-bottom: 8px;
  border-bottom: 2px solid var(--primary-light);
}

.article-body h3 {
  font-size: 20px;
  font-weight: 700;
  margin: 28px 0 12px;
  color: var(--dark);
}

.article-body p {
  margin-bottom: 20px;
}

.article-body ul, .article-body ol {
  margin: 0 0 24px 24px;
}

.article-body li {
  margin-bottom: 8px;
}

.article-callout {
  background: var(--primary-light);
  border-left: 4px solid var(--primary);
  padding: 20px 24px;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  margin: 32px 0;
}

.article-callout h4 {
  font-size: 16px;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 8px;
}

.article-sidebar {
  display: flex;
  flex-direction: column;
  gap: 32px;
}

.sidebar-widget {
  background: #FAFAFC;
  padding: 24px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
}

.sidebar-widget h4 {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-color);
}

.widget-link-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.widget-link-list a {
  font-size: 14px;
  color: var(--dark-gray);
  line-height: 1.5;
}

.widget-link-list a:hover {
  color: var(--primary);
}

.cta-widget {
  background: linear-gradient(135deg, #1D1D1F, #323236);
  color: #ffffff;
  text-align: center;
}

.cta-widget h4 {
  border-bottom: none;
  color: #ffffff;
  font-size: 20px;
}

.cta-widget p {
  font-size: 14px;
  color: #D2D2D7;
  margin-bottom: 20px;
}

/* Responsive Styles */
@media (max-width: 1024px) {
  .hero-stats {
    grid-template-columns: repeat(2, 1fr);
  }
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .pricing-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .article-layout {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .hero-title {
    font-size: 34px;
  }
  .main-nav {
    display: none;
    position: absolute;
    top: 72px;
    left: 0;
    width: 100%;
    background: #ffffff;
    flex-direction: column;
    padding: 24px;
    border-bottom: 1px solid var(--border-color);
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
  }
  .main-nav.active {
    display: flex;
  }
  .mobile-menu-btn {
    display: block;
  }
  .features-grid, .testimonials-grid, .articles-grid, .pricing-grid {
    grid-template-columns: 1fr;
  }
  .hero-stats {
    grid-template-columns: 1fr;
  }
}

/* ==========================================
   Download Modal Styles (Core Task 4)
   ========================================== */
body.modal-open {
  overflow: hidden !important;
}

.download-modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(15, 15, 20, 0.68);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 9999;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s cubic-bezier(0.25, 0.8, 0.25, 1), visibility 0.3s;
  padding: 16px;
}

.download-modal-overlay.active {
  opacity: 1;
  visibility: visible;
}

.download-modal {
  background: #ffffff;
  border-radius: var(--radius-lg);
  box-shadow: 0 25px 60px rgba(0, 0, 0, 0.25);
  border: 1px solid rgba(228, 0, 43, 0.15);
  max-width: 520px;
  width: 100%;
  padding: 32px 28px 24px;
  position: relative;
  transform: scale(0.94) translateY(15px);
  transition: transform 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
  color: var(--dark);
}

.download-modal-overlay.active .download-modal {
  transform: scale(1) translateY(0);
}

.modal-close-btn {
  position: absolute;
  top: 18px;
  right: 18px;
  background: #F5F5F7;
  border: none;
  font-size: 24px;
  line-height: 1;
  color: var(--dark-gray);
  width: 36px;
  height: 36px;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition);
}

.modal-close-btn:hover,
.modal-close-btn:focus {
  background: var(--primary-light);
  color: var(--primary);
  outline: none;
}

.modal-header {
  text-align: center;
  margin-bottom: 18px;
}

.modal-icon-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 52px;
  height: 52px;
  border-radius: 16px;
  background: var(--primary-light);
  color: var(--primary);
  font-size: 26px;
  margin-bottom: 12px;
  box-shadow: 0 4px 15px rgba(228, 0, 43, 0.12);
}

.modal-title {
  font-size: 22px;
  font-weight: 800;
  color: var(--dark);
  margin-bottom: 6px;
  letter-spacing: -0.3px;
}

.modal-subtitle {
  font-size: 14px;
  color: var(--dark-gray);
  line-height: 1.5;
}

.modal-plan-intent {
  background: var(--primary-light);
  border: 1px solid rgba(228, 0, 43, 0.2);
  border-radius: var(--radius-md);
  padding: 10px 16px;
  margin-bottom: 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
}

.modal-plan-tag {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 14px;
  color: var(--primary);
  font-weight: 700;
}

.modal-plan-tip {
  font-size: 13px;
  color: var(--primary);
  font-weight: 600;
}

.modal-platform-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: 20px;
}

.modal-platform-card {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 16px;
  background: #FAFAFC;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  transition: var(--transition);
  color: var(--dark);
  text-decoration: none;
}

.modal-platform-card:hover,
.modal-platform-card:focus {
  background: #ffffff;
  border-color: var(--primary);
  transform: translateX(4px);
  box-shadow: 0 6px 20px rgba(228, 0, 43, 0.1);
  outline: none;
}

.platform-card-left {
  display: flex;
  align-items: center;
  gap: 12px;
}

.platform-card-icon {
  font-size: 24px;
  width: 38px;
  height: 38px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: #ffffff;
  border-radius: 10px;
  border: 1px solid var(--border-color);
  flex-shrink: 0;
}

.platform-card-info h4 {
  font-size: 15px;
  font-weight: 700;
  color: var(--dark);
  margin-bottom: 2px;
}

.platform-card-info p {
  font-size: 12px;
  color: var(--dark-gray);
}

.platform-card-action {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  font-weight: 700;
  color: var(--primary);
  flex-shrink: 0;
}

.modal-footer {
  text-align: center;
  border-top: 1px solid var(--border-color);
  padding-top: 16px;
}

.modal-footer-note {
  font-size: 12px;
  color: var(--dark-gray);
  margin-bottom: 10px;
  line-height: 1.5;
}

.modal-footer-links {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  font-size: 13px;
  flex-wrap: wrap;
}

.modal-footer-links a {
  color: var(--primary);
  font-weight: 600;
  transition: var(--transition);
}

.modal-footer-links a:hover {
  text-decoration: underline;
  color: var(--primary-hover);
}