/* -------------------------------------------------------------------------- */
/* 雪橇云 (xueqiaoyun.cfd) 官方 Landing Page 全局样式表                         */
/* Design System: Ice & Snow Glassmorphism Theme                              */
/* -------------------------------------------------------------------------- */

:root {
  --primary: #1e88e5;
  --primary-hover: #1565c0;
  --primary-light: #e3f2fd;
  --accent: #0288d1;
  --accent-glow: rgba(2, 136, 209, 0.35);
  
  --bg-dark: #0f172a;
  --bg-light: #f8fafc;
  --surface: #ffffff;
  --surface-glass: rgba(255, 255, 255, 0.75);
  --surface-glass-dark: rgba(15, 23, 42, 0.65);
  
  --text-main: #1e293b;
  --text-muted: #64748b;
  --text-light: #94a3b8;
  --text-white: #ffffff;
  
  --border-light: rgba(226, 232, 240, 0.8);
  --border-glass: rgba(255, 255, 255, 0.3);
  
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --shadow-sm: 0 2px 4px rgba(0,0,0,0.05);
  --shadow-md: 0 10px 25px -5px rgba(0, 0, 0, 0.08), 0 8px 10px -6px rgba(0, 0, 0, 0.04);
  --shadow-lg: 0 20px 35px -10px rgba(14, 165, 233, 0.15);
  
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-full: 9999px;
  
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-family);
  background-color: var(--bg-light);
  color: var(--text-main);
  line-height: 1.6;
  overflow-x: hidden;
}

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

ul {
  list-style: none;
}

.container {
  width: 100%;
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Header Navbar */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 80px;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-light);
  display: flex;
  align-items: center;
  transition: var(--transition);
}

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

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--text-main);
  letter-spacing: -0.5px;
}

.brand img {
  width: 38px;
  height: 38px;
  object-fit: contain;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 2rem;
}

.nav-link {
  font-size: 0.95rem;
  font-weight: 500;
  color: #334155;
}

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

.nav-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.7rem 1.6rem;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  cursor: pointer;
  border: 1px solid transparent;
  transition: var(--transition);
  white-space: nowrap;
}

.btn-primary {
  background: linear-gradient(135deg, #1e88e5 0%, #0288d1 100%);
  color: var(--text-white);
  box-shadow: 0 4px 14px rgba(2, 136, 209, 0.35);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(2, 136, 209, 0.5);
  background: linear-gradient(135deg, #1565c0 0%, #0277bd 100%);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.9);
  color: var(--primary);
  border: 1.5px solid var(--primary);
  backdrop-filter: blur(4px);
}

.btn-secondary:hover {
  background: var(--primary);
  color: var(--text-white);
  transform: translateY(-2px);
  box-shadow: 0 4px 14px rgba(30, 136, 229, 0.25);
}

.mobile-menu-toggle {
  display: none;
  font-size: 1.5rem;
  background: none;
  border: none;
  cursor: pointer;
  color: var(--text-main);
}

/* Hero Section */
.hero {
  position: relative;
  min-height: 100vh;
  padding-top: 140px;
  padding-bottom: 100px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(180deg, #dbeafe 0%, #eff6ff 40%, #ffffff 100%);
  overflow: hidden;
}

/* Snow particle canvas overlay */
#snow-canvas {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 1;
}

.hero-bg-overlay {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-image: radial-gradient(circle at 50% 25%, rgba(255,255,255,0.75) 0%, rgba(224,242,254,0.4) 60%, rgba(186,230,253,0.2) 100%),
                    url('./sled_bg.svg');
  background-position: center bottom;
  background-repeat: no-repeat;
  background-size: cover;
  z-index: 0;
}

.hero-content {
  position: relative;
  z-index: 2;
  text-align: center;
  max-width: 860px;
  margin: 0 auto;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  border-radius: var(--radius-full);
  background: rgba(255, 255, 255, 0.9);
  border: 1px solid rgba(186, 230, 253, 0.8);
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--primary);
  margin-bottom: 1.5rem;
  box-shadow: 0 4px 12px rgba(14, 165, 233, 0.1);
}

.hero-title {
  font-size: 3.25rem;
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -1px;
  color: #0f172a;
  margin-bottom: 1.25rem;
}

.hero-subtitle {
  font-size: 1.15rem;
  color: #475569;
  line-height: 1.7;
  margin-bottom: 2.5rem;
  max-width: 760px;
  margin-left: auto;
  margin-right: auto;
}

.hero-buttons {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1.25rem;
  flex-wrap: wrap;
}

.hero-buttons .btn {
  padding: 0.85rem 2.25rem;
  font-size: 1.05rem;
}

/* Feature Highlights Grid */
.features-section {
  padding: 100px 0;
  background: #ffffff;
  position: relative;
}

.section-header {
  text-align: center;
  max-width: 680px;
  margin: 0 auto 4rem auto;
}

.section-tag {
  font-size: 0.875rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--primary);
  letter-spacing: 1px;
  margin-bottom: 0.5rem;
  display: block;
}

.section-title {
  font-size: 2.25rem;
  font-weight: 800;
  color: #0f172a;
  letter-spacing: -0.5px;
  margin-bottom: 1rem;
}

.section-subtitle {
  font-size: 1.05rem;
  color: var(--text-muted);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2rem;
}

.feature-card {
  background: #ffffff;
  border-radius: var(--radius-md);
  padding: 2.25rem;
  border: 1px solid var(--border-light);
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.feature-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-md);
  border-color: rgba(186, 230, 253, 0.8);
}

.feature-icon {
  width: 56px;
  height: 56px;
  border-radius: 14px;
  background: var(--primary-light);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
}

.feature-card h3 {
  font-size: 1.3rem;
  font-weight: 700;
  color: #0f172a;
}

.feature-card p {
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.65;
}

/* Streaming & AI Section */
.unlock-section {
  padding: 90px 0;
  background: linear-gradient(180deg, #f8fafc 0%, #e0f2fe 100%);
}

.unlock-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.5rem;
  margin-top: 3rem;
}

.unlock-card {
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(10px);
  border-radius: var(--radius-md);
  padding: 1.75rem;
  border: 1px solid rgba(255, 255, 255, 0.6);
  box-shadow: var(--shadow-sm);
  text-align: center;
  transition: var(--transition);
}

.unlock-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  background: #ffffff;
}

.unlock-card-icon {
  font-size: 2.5rem;
  margin-bottom: 0.75rem;
}

.unlock-card h4 {
  font-size: 1.15rem;
  font-weight: 700;
  color: #0f172a;
  margin-bottom: 0.5rem;
}

.unlock-card p {
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* Pricing Section */
.pricing-section {
  padding: 100px 0;
  background: #ffffff;
}

.pricing-discount-banner {
  background: linear-gradient(135deg, #0288d1 0%, #1e88e5 100%);
  color: #ffffff;
  padding: 1rem 2rem;
  border-radius: var(--radius-md);
  text-align: center;
  font-weight: 600;
  font-size: 1.05rem;
  margin-bottom: 3rem;
  box-shadow: 0 4px 15px rgba(2, 136, 209, 0.25);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
}

.discount-code {
  background: rgba(255, 255, 255, 0.25);
  padding: 4px 12px;
  border-radius: 6px;
  font-family: monospace;
  font-size: 1.1rem;
  letter-spacing: 1px;
  border: 1px stroke rgba(255,255,255,0.4);
}

.pricing-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(270px, 1fr));
  gap: 2rem;
  align-items: stretch;
}

.pricing-card {
  background: #ffffff;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-light);
  padding: 2.5rem 2rem;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: var(--transition);
}

.pricing-card.popular {
  border-color: var(--primary);
  box-shadow: var(--shadow-lg);
  transform: scale(1.03);
}

.popular-badge {
  position: absolute;
  top: -14px;
  right: 24px;
  background: linear-gradient(135deg, #1e88e5 0%, #0288d1 100%);
  color: #ffffff;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  padding: 4px 14px;
  border-radius: var(--radius-full);
}

.pricing-header h3 {
  font-size: 1.35rem;
  font-weight: 700;
  color: #0f172a;
  margin-bottom: 0.5rem;
}

.pricing-header p {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
}

.pricing-price {
  font-size: 2.75rem;
  font-weight: 800;
  color: #0f172a;
  margin-bottom: 1.5rem;
  display: flex;
  align-items: baseline;
}

.pricing-price span {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-muted);
  margin-left: 4px;
}

.pricing-features {
  margin-bottom: 2rem;
  flex-grow: 1;
}

.pricing-features li {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.95rem;
  color: #334155;
  margin-bottom: 0.85rem;
}

.pricing-features li svg {
  width: 18px;
  height: 18px;
  color: #10b981;
  flex-shrink: 0;
}

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

/* User Reviews / Evaluation Section */
.reviews-section {
  padding: 100px 0;
  background: var(--bg-light);
}

.reviews-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2rem;
}

.review-card {
  background: #ffffff;
  border-radius: var(--radius-md);
  padding: 2rem;
  border: 1px solid var(--border-light);
  box-shadow: var(--shadow-sm);
}

.review-header {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1rem;
}

.review-avatar {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--primary-light);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1.1rem;
}

.review-user-info h4 {
  font-size: 1rem;
  font-weight: 700;
  color: #0f172a;
}

.review-user-info p {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.review-stars {
  color: #f59e0b;
  margin-bottom: 0.75rem;
  font-size: 0.9rem;
}

.review-text {
  font-size: 0.95rem;
  color: #334155;
  line-height: 1.6;
}

/* FAQ Section */
.faq-section {
  padding: 100px 0;
  background: #ffffff;
}

.faq-accordion {
  max-width: 840px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

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

.faq-question {
  width: 100%;
  padding: 1.35rem 1.75rem;
  background: #ffffff;
  border: none;
  text-align: left;
  font-size: 1.05rem;
  font-weight: 700;
  color: #0f172a;
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
}

.faq-question:hover {
  background: #f8fafc;
  color: var(--primary);
}

.faq-icon {
  font-size: 1.25rem;
  transition: transform 0.3s ease;
}

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

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease, padding 0.35s ease;
  background: #f8fafc;
  padding: 0 1.75rem;
  color: #475569;
  font-size: 0.95rem;
  line-height: 1.7;
}

.faq-item.active .faq-answer {
  max-height: 300px;
  padding: 1rem 1.75rem 1.5rem 1.75rem;
}

/* Knowledge Base / SEO Articles Section */
.articles-section {
  padding: 90px 0;
  background: var(--bg-light);
}

.articles-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2rem;
}

.article-card {
  background: #ffffff;
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--border-light);
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  display: flex;
  flex-direction: column;
}

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

.article-card-body {
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  flex-grow: 1;
}

.article-tag {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--primary);
  background: var(--primary-light);
  padding: 4px 10px;
  border-radius: 4px;
  align-self: flex-start;
  margin-bottom: 0.75rem;
}

.article-card h3 {
  font-size: 1.15rem;
  font-weight: 700;
  color: #0f172a;
  line-height: 1.4;
  margin-bottom: 0.75rem;
}

.article-card p {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 1.25rem;
  flex-grow: 1;
}

.article-read-more {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--primary);
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

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

/* Article Template Specific Styles */
.article-page {
  padding-top: 120px;
  padding-bottom: 100px;
  background: #ffffff;
}

.article-container {
  max-width: 860px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.article-header {
  margin-bottom: 2.5rem;
  border-bottom: 1px solid var(--border-light);
  padding-bottom: 2rem;
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 1rem;
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 1rem;
}

.article-title {
  font-size: 2.5rem;
  font-weight: 800;
  color: #0f172a;
  line-height: 1.3;
  margin-bottom: 1rem;
}

.article-content {
  font-size: 1.05rem;
  line-height: 1.85;
  color: #334155;
}

.article-content h2 {
  font-size: 1.65rem;
  font-weight: 700;
  color: #0f172a;
  margin: 2.25rem 0 1rem 0;
}

.article-content h3 {
  font-size: 1.3rem;
  font-weight: 700;
  color: #1e293b;
  margin: 1.75rem 0 0.75rem 0;
}

.article-content p {
  margin-bottom: 1.25rem;
}

.article-content ul, .article-content ol {
  margin-bottom: 1.5rem;
  padding-left: 1.5rem;
}

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

.article-callout {
  background: var(--primary-light);
  border-left: 4px solid var(--primary);
  padding: 1.25rem 1.5rem;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin: 1.5rem 0;
  font-size: 1rem;
}

.article-navigation {
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border-light);
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

/* Footer & PBN Section */
footer {
  background: #0f172a;
  color: #94a3b8;
  padding: 3rem 1.5rem 2rem 1.5rem;
  font-size: 0.85rem;
  text-align: center;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1.25rem;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 8px;
  color: #ffffff;
  font-weight: 700;
  font-size: 1.1rem;
}

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

.footer-links {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  flex-wrap: wrap;
  justify-content: center;
}

/* PBN Friendly Links Styling */
.pbn-links-area {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1.25rem;
  margin-top: 0.75rem;
  padding-top: 1rem;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  width: 100%;
  max-width: 600px;
  font-size: 0.8rem;
  color: #64748b;
}

.pbn-links-area span {
  opacity: 0.7;
}

.pbn-links-area a {
  color: #94a3b8;
  text-decoration: none;
  transition: var(--transition);
  font-weight: 500;
}

.pbn-links-area a:hover {
  color: #38bdf8;
}

/* Responsive Media Queries */
@media (max-width: 992px) {
  .hero-title {
    font-size: 2.5rem;
  }
  .pricing-card.popular {
    transform: scale(1);
  }
}

@media (max-width: 768px) {
  .navbar-inner {
    padding: 0 0.5rem;
  }
  .nav-menu {
    display: none; /* Can be toggled with mobile js */
  }
  .mobile-menu-toggle {
    display: block;
  }
  .hero-title {
    font-size: 2rem;
  }
  .hero-subtitle {
    font-size: 1rem;
  }
  .section-title {
    font-size: 1.75rem;
  }
}