/* ==========================================================================
   青云梯 (Qingyunti) - Editorial Minimalist Styling
   Domain: qingyunti-jc.homes
   ========================================================================== */

:root {
  --bg-dark: #080B10;
  --bg-card: #111622;
  --bg-card-hover: #182030;
  --bg-glass: rgba(17, 22, 34, 0.75);
  --border-color: rgba(255, 255, 255, 0.08);
  --border-glow: rgba(79, 172, 254, 0.3);
  
  --text-main: #F3F4F6;
  --text-muted: #9CA3AF;
  --text-dim: #6B7280;
  
  --accent-cyan: #00F2FE;
  --accent-blue: #4FACFE;
  --accent-purple: #7F00FF;
  --accent-gradient: linear-gradient(135deg, #00F2FE 0%, #4FACFE 50%, #7F00FF 100%);
  --accent-gradient-hover: linear-gradient(135deg, #38f9d7 0%, #4FACFE 50%, #6e00ff 100%);
  
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 24px;
  --radius-pill: 9999px;
  
  --shadow-glow: 0 10px 30px -10px rgba(0, 242, 254, 0.25);
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "SimHei", sans-serif;
  --font-heading: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  
  --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 0.35s cubic-bezier(0.16, 1, 0.3, 1);
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  background-color: var(--bg-dark);
  color: var(--text-main);
  font-family: var(--font-family);
  -webkit-font-smoothing: antialiased;
}

body {
  overflow-x: hidden;
  line-height: 1.65;
  background: var(--bg-dark);
  background-image: 
    radial-gradient(circle at 15% 15%, rgba(0, 242, 254, 0.05) 0%, transparent 45%),
    radial-gradient(circle at 85% 65%, rgba(127, 0, 255, 0.05) 0%, transparent 50%);
  background-attachment: fixed;
}

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

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

ul, ol {
  list-style: none;
}

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

/* Header & Nav */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(8, 11, 16, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-color);
  transition: all var(--transition-fast);
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 76px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 1.5rem;
  font-weight: 900;
  letter-spacing: -0.02em;
  color: #fff;
}

.logo-icon {
  width: 38px;
  height: 38px;
  background: var(--accent-gradient);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-glow);
  font-size: 1.2rem;
}

.logo-text {
  font-family: var(--font-heading);
  background: linear-gradient(180deg, #FFFFFF 0%, #D1D5DB 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

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

.nav-link {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-muted);
  position: relative;
  padding: 0.5rem 0;
}

.nav-link:hover, .nav-link.active {
  color: #fff;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0%;
  height: 2px;
  background: var(--accent-cyan);
  transition: width var(--transition-fast);
  border-radius: 2px;
}

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

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

/* Button Styles */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.75rem;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: var(--radius-pill);
  cursor: pointer;
  transition: all var(--transition-normal);
  border: 1px solid transparent;
  outline: none;
  text-align: center;
  white-space: nowrap;
}

.btn-primary {
  background: var(--accent-gradient);
  color: #000;
  font-weight: 700;
  box-shadow: 0 4px 20px rgba(0, 242, 254, 0.3);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(0, 242, 254, 0.5);
  color: #000;
}

.btn-primary:focus-visible {
  outline: 2px solid var(--accent-cyan);
  outline-offset: 3px;
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.05);
  color: var(--text-main);
  border-color: var(--border-color);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.12);
  border-color: rgba(255, 255, 255, 0.2);
  transform: translateY(-2px);
}

.btn-secondary:focus-visible {
  outline: 2px solid var(--accent-blue);
  outline-offset: 3px;
}

.btn-outline-glow {
  background: transparent;
  color: var(--accent-cyan);
  border: 1px solid rgba(0, 242, 254, 0.4);
}

.btn-outline-glow:hover {
  background: rgba(0, 242, 254, 0.1);
  box-shadow: 0 0 20px rgba(0, 242, 254, 0.2);
}

/* Editorial Hero Section */
.hero-section {
  padding: 5rem 0 4rem 0;
  position: relative;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 3.5rem;
  align-items: center;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.4rem 1rem;
  background: rgba(0, 242, 254, 0.08);
  border: 1px solid rgba(0, 242, 254, 0.25);
  border-radius: var(--radius-pill);
  font-size: 0.85rem;
  color: var(--accent-cyan);
  font-weight: 600;
  margin-bottom: 1.5rem;
}

.hero-title {
  font-size: 3.5rem;
  line-height: 1.15;
  font-weight: 900;
  font-family: var(--font-heading);
  letter-spacing: -0.03em;
  margin-bottom: 1.5rem;
}

.hero-title .highlight {
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-subtitle {
  font-size: 1.2rem;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 2.2rem;
  max-width: 600px;
}

.hero-cta-group {
  display: flex;
  align-items: center;
  gap: 1.2rem;
  flex-wrap: wrap;
}

.hero-meta {
  display: flex;
  align-items: center;
  gap: 2rem;
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border-color);
}

.meta-item {
  display: flex;
  flex-direction: column;
}

.meta-number {
  font-size: 1.75rem;
  font-weight: 800;
  color: #fff;
}

.meta-label {
  font-size: 0.85rem;
  color: var(--text-dim);
}

/* Hero Cards / Visual Column */
.hero-visual {
  position: relative;
}

.magazine-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  position: relative;
  overflow: hidden;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.4);
  transition: transform var(--transition-normal), border-color var(--transition-normal);
}

.magazine-card:hover {
  border-color: var(--border-glow);
  transform: translateY(-4px);
}

.speed-meter {
  display: flex;
  flex-direction: column;
  gap: 1.2rem;
}

.meter-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.meter-title {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.meter-value {
  font-size: 2.8rem;
  font-weight: 900;
  color: var(--accent-cyan);
  line-height: 1;
}

.stat-bars {
  display: flex;
  flex-direction: column;
  gap: 0.8rem;
}

.stat-bar-item {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}

.stat-bar-label {
  display: flex;
  justify-content: space-between;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.progress-bg {
  height: 8px;
  background: rgba(255, 255, 255, 0.06);
  border-radius: 4px;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: var(--accent-gradient);
  border-radius: 4px;
  transition: width 1s ease-out;
}

/* Feature Grid Section */
.section {
  padding: 5rem 0;
  position: relative;
}

.section-header {
  text-align: center;
  max-width: 700px;
  margin: 0 auto 3.5rem auto;
}

.section-tag {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--accent-cyan);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 0.75rem;
  display: block;
}

.section-title {
  font-size: 2.5rem;
  font-weight: 900;
  font-family: var(--font-heading);
  letter-spacing: -0.02em;
  margin-bottom: 1rem;
}

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

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

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 2.2rem;
  transition: all var(--transition-normal);
  display: flex;
  flex-direction: column;
}

.feature-card:hover {
  background: var(--bg-card-hover);
  border-color: rgba(0, 242, 254, 0.3);
  transform: translateY(-6px);
  box-shadow: 0 15px 35px rgba(0, 0, 0, 0.3);
}

.feature-icon {
  width: 54px;
  height: 54px;
  border-radius: 14px;
  background: rgba(0, 242, 254, 0.1);
  border: 1px solid rgba(0, 242, 254, 0.2);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  color: var(--accent-cyan);
  margin-bottom: 1.5rem;
}

.feature-title {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 0.8rem;
  color: #fff;
}

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

/* Streaming & AI Support Grid */
.streaming-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
}

.service-chip {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  display: flex;
  align-items: center;
  gap: 1.2rem;
  transition: all var(--transition-fast);
}

.service-chip:hover {
  border-color: rgba(255, 255, 255, 0.2);
  background: var(--bg-card-hover);
  transform: translateY(-2px);
}

.service-icon {
  width: 44px;
  height: 44px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 1.1rem;
  flex-shrink: 0;
}

.service-info h4 {
  font-size: 1.05rem;
  font-weight: 700;
  color: #fff;
}

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

/* Pricing Grid */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
  align-items: stretch;
}

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

.pricing-card.popular {
  border-color: var(--accent-cyan);
  background: linear-gradient(180deg, rgba(0, 242, 254, 0.05) 0%, var(--bg-card) 100%);
  box-shadow: 0 0 30px rgba(0, 242, 254, 0.15);
  transform: scale(1.03);
}

.pricing-badge {
  position: absolute;
  top: -14px;
  right: 2rem;
  background: var(--accent-gradient);
  color: #000;
  font-size: 0.8rem;
  font-weight: 800;
  padding: 0.25rem 0.9rem;
  border-radius: var(--radius-pill);
  text-transform: uppercase;
}

.pricing-name {
  font-size: 1.4rem;
  font-weight: 800;
  color: #fff;
  margin-bottom: 0.5rem;
}

.pricing-desc {
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
  height: 40px;
}

.pricing-price {
  font-size: 3rem;
  font-weight: 900;
  color: #fff;
  line-height: 1;
  margin-bottom: 1.5rem;
  font-family: var(--font-heading);
}

.pricing-price span {
  font-size: 1rem;
  font-weight: 500;
  color: var(--text-muted);
}

.pricing-features {
  margin-bottom: 2rem;
  display: flex;
  flex-direction: column;
  gap: 0.8rem;
  flex-grow: 1;
}

.pricing-feature {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 0.92rem;
  color: var(--text-muted);
}

.pricing-feature svg {
  color: var(--accent-cyan);
  flex-shrink: 0;
}

/* FAQ Accordion */
.faq-list {
  max-width: 840px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 1.2rem;
}

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

.faq-item:hover {
  border-color: rgba(255, 255, 255, 0.2);
}

.faq-question {
  width: 100%;
  padding: 1.5rem;
  background: transparent;
  border: none;
  color: #fff;
  font-size: 1.1rem;
  font-weight: 700;
  text-align: left;
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  font-family: var(--font-family);
}

.faq-question:focus-visible {
  outline: 2px solid var(--accent-cyan);
  outline-offset: -2px;
}

.faq-icon {
  width: 24px;
  height: 24px;
  transition: transform var(--transition-fast);
  color: var(--accent-cyan);
}

.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;
  color: var(--text-muted);
  font-size: 0.98rem;
  line-height: 1.7;
}

.faq-item.active .faq-answer {
  max-height: 300px;
  padding: 0 1.5rem 1.5rem 1.5rem;
}

/* Fixed Section Navigator (Right Side Arrows) */
.section-nav-fixed {
  position: fixed;
  right: 1.5rem;
  top: 50%;
  transform: translateY(-50%);
  z-index: 99;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  background: rgba(17, 22, 34, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border-color);
  padding: 0.5rem;
  border-radius: var(--radius-pill);
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.5);
}

.section-nav-btn {
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-fast);
  font-size: 1.1rem;
}

.section-nav-btn:hover:not(:disabled) {
  background: var(--accent-gradient);
  color: #000;
  border-color: transparent;
  transform: scale(1.1);
}

.section-nav-btn:disabled {
  opacity: 0.25;
  cursor: not-allowed;
  border-color: transparent;
}

.section-nav-btn:focus-visible {
  outline: 2px solid var(--accent-cyan);
}

/* Footer */
.site-footer {
  background: #040609;
  border-top: 1px solid var(--border-color);
  padding: 4rem 0 2.5rem 0;
  margin-top: 4rem;
}

.footer-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-bottom: 2.5rem;
  border-bottom: 1px solid var(--border-color);
  margin-bottom: 2.5rem;
  flex-wrap: wrap;
  gap: 1.5rem;
}

.footer-brand p {
  color: var(--text-dim);
  font-size: 0.9rem;
  margin-top: 0.5rem;
}

.footer-links {
  display: flex;
  gap: 2rem;
  flex-wrap: wrap;
}

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

.footer-link:hover {
  color: var(--accent-cyan);
}

.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.85rem;
  color: var(--text-dim);
  flex-wrap: wrap;
  gap: 1rem;
}

/* Editorial / Article Layout */
.article-page {
  padding: 4rem 0;
}

.article-header {
  max-width: 820px;
  margin: 0 auto 3rem auto;
  text-align: center;
}

.article-category {
  display: inline-block;
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--accent-cyan);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 1rem;
}

.article-title {
  font-size: 2.8rem;
  font-weight: 900;
  line-height: 1.25;
  font-family: var(--font-heading);
  margin-bottom: 1.5rem;
  color: #fff;
}

.article-meta {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1.5rem;
  color: var(--text-dim);
  font-size: 0.9rem;
}

.article-body {
  max-width: 800px;
  margin: 0 auto;
  font-size: 1.08rem;
  line-height: 1.85;
  color: #D1D5DB;
}

.article-body h2 {
  font-size: 1.8rem;
  font-weight: 800;
  color: #fff;
  margin: 2.5rem 0 1.2rem 0;
  font-family: var(--font-heading);
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border-color);
}

.article-body h3 {
  font-size: 1.35rem;
  font-weight: 700;
  color: #F3F4F6;
  margin: 1.8rem 0 1.0rem 0;
}

.article-body p {
  margin-bottom: 1.5rem;
}

.article-body ul, .article-body ol {
  margin-bottom: 1.5rem;
  padding-left: 1.8rem;
}

.article-body ul {
  list-style: disc;
}

.article-body ol {
  list-style: decimal;
}

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

.article-cta-box {
  background: linear-gradient(135deg, rgba(0, 242, 254, 0.1) 0%, rgba(127, 0, 255, 0.1) 100%);
  border: 1px solid var(--accent-cyan);
  border-radius: var(--radius-md);
  padding: 2rem;
  margin: 3rem 0;
  text-align: center;
}

.article-cta-box h4 {
  font-size: 1.4rem;
  font-weight: 800;
  color: #fff;
  margin-bottom: 0.75rem;
}

.article-cta-box p {
  font-size: 0.98rem;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
}

/* Articles List Grid */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
  margin-top: 3rem;
}

.article-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.8rem;
  display: flex;
  flex-direction: column;
  transition: all var(--transition-normal);
}

.article-card:hover {
  border-color: rgba(0, 242, 254, 0.3);
  transform: translateY(-5px);
  background: var(--bg-card-hover);
}

.article-card-date {
  font-size: 0.8rem;
  color: var(--text-dim);
  margin-bottom: 0.75rem;
}

.article-card-title {
  font-size: 1.25rem;
  font-weight: 800;
  color: #fff;
  margin-bottom: 0.8rem;
  line-height: 1.35;
}

.article-card-title a:hover {
  color: var(--accent-cyan);
}

.article-card-excerpt {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 1.5rem;
  flex-grow: 1;
}

.article-card-link {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--accent-cyan);
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}

/* Mobile responsive styles */
@media (max-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 2.5rem;
  }
  
  .features-grid, .pricing-grid, .articles-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .streaming-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .hero-title {
    font-size: 2.4rem;
  }
  
  .features-grid, .pricing-grid, .streaming-grid, .articles-grid {
    grid-template-columns: 1fr;
  }
  
  .pricing-card.popular {
    transform: none;
  }
  
  .nav-links {
    display: none; /* Can be toggled or compact on mobile */
  }
  
  .section-nav-fixed {
    right: 0.75rem;
    padding: 0.35rem;
    gap: 0.4rem;
  }
  
  .section-nav-btn {
    width: 36px;
    height: 36px;
    font-size: 0.95rem;
  }
  
  .article-title {
    font-size: 2rem;
  }
}

/* Prefers Reduced Motion */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}