/* -------------------------------------------------------------
   龙猫云 (TTR Cloud / TotoroCloud) - 官网 Landing Page Core CSS
   Design Theme: 极简苹果白 (Minimalist Apple White) + 科技黑框 (Black Frame Borders)
   Domain: ttrcloud.xyz
   ------------------------------------------------------------- */

:root {
  --bg-primary: #FFFFFF;
  --bg-secondary: #F8FAFC;
  --bg-tertiary: #F1F5F9;
  --text-main: #0F172A;
  --text-muted: #475569;
  --text-light: #94A3B8;
  --black-border: 2px solid #000000;
  --black-border-thick: 3px solid #000000;
  --black-border-thin: 1.5px solid #000000;
  --brand-accent: #2563EB;
  --brand-accent-hover: #1D4ED8;
  --brand-dark: #0F172A;
  --green-glow: #10B981;
  --border-radius-lg: 16px;
  --border-radius-md: 12px;
  --border-radius-sm: 8px;
  --shadow-apple: 0 4px 20px -2px rgba(0, 0, 0, 0.06);
  --shadow-bold: 4px 4px 0px #000000;
  --transition-fast: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

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

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text", "Helvetica Neue", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background-color: var(--bg-secondary);
  color: var(--text-main);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

/* Links & Buttons */
a {
  color: inherit;
  text-decoration: none;
}

/* Black Frame Utility Class for all Card Containers */
.black-frame {
  border: var(--black-border);
  border-radius: var(--border-radius-lg);
  background-color: var(--bg-primary);
  box-shadow: var(--shadow-apple);
  transition: var(--transition-fast);
}

.black-frame:hover {
  box-shadow: 6px 6px 0px #000000;
  transform: translateY(-2px);
}

/* Container */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* Header & Navigation */
.header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: var(--black-border);
}

.nav-wrapper {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.logo-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 800;
  font-size: 1.35rem;
  letter-spacing: -0.5px;
  color: var(--text-main);
}

.logo-icon {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: transparent;
}

.logo-icon img {
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
  list-style: none;
}

.nav-link {
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--text-muted);
  transition: var(--transition-fast);
}

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

.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 22px;
  font-weight: 700;
  font-size: 0.95rem;
  background-color: #000000;
  color: #FFFFFF;
  border: var(--black-border);
  border-radius: 999px;
  cursor: pointer;
  transition: var(--transition-fast);
  box-shadow: 2px 2px 0px rgba(0, 0, 0, 0.2);
}

.btn-primary:hover {
  background-color: var(--brand-accent);
  color: #FFFFFF;
  border-color: #000000;
  box-shadow: 4px 4px 0px #000000;
  transform: translateY(-2px);
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 22px;
  font-weight: 700;
  font-size: 0.95rem;
  background-color: #FFFFFF;
  color: #000000;
  border: var(--black-border);
  border-radius: 999px;
  cursor: pointer;
  transition: var(--transition-fast);
}

.btn-secondary:hover {
  background-color: var(--bg-tertiary);
  box-shadow: 3px 3px 0px #000000;
}

/* HERO SECTION with H1 Branding */
.hero-section {
  padding: 80px 0 60px;
  text-align: center;
  background: radial-gradient(circle at 50% 20%, rgba(37, 99, 235, 0.04) 0%, transparent 60%);
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  border: var(--black-border-thin);
  border-radius: 999px;
  background-color: #FFFFFF;
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--brand-accent);
  margin-bottom: 24px;
}

.hero-badge .pulse-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--green-glow);
  box-shadow: 0 0 8px var(--green-glow);
  animation: pulseGlow 2s infinite;
}

@keyframes pulseGlow {
  0% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.4; transform: scale(1.3); }
  100% { opacity: 1; transform: scale(1); }
}

/* Directive 3: H1 title must contain Brand Name (龙猫云) */
.hero-title-h1 {
  font-size: 2.75rem;
  font-weight: 900;
  line-height: 1.25;
  letter-spacing: -1px;
  color: var(--text-main);
  max-width: 900px;
  margin: 0 auto 20px;
}

.hero-title-h1 span.brand-highlight {
  color: var(--brand-accent);
  background: linear-gradient(135deg, #2563EB 0%, #1D4ED8 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-subtitle {
  font-size: 1.15rem;
  color: var(--text-muted);
  max-width: 760px;
  margin: 0 auto 36px;
  font-weight: 500;
}

.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin-bottom: 40px;
  flex-wrap: wrap;
}

.hero-features-strip {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px;
  margin-top: 48px;
}

.feature-pill {
  padding: 16px 20px;
  display: flex;
  align-items: center;
  gap: 14px;
  border: var(--black-border);
  border-radius: var(--border-radius-md);
  background: #FFFFFF;
  box-shadow: var(--shadow-apple);
}

.feature-pill-icon {
  width: 40px;
  height: 40px;
  border-radius: 8px;
  border: var(--black-border-thin);
  background: var(--bg-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
}

.feature-pill-text {
  text-align: left;
}

.feature-pill-title {
  font-weight: 700;
  font-size: 0.95rem;
}

.feature-pill-desc {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* DIRECTIVE 4: H2 Pricing Plans Section - Dynamic side-by-side swipeable slider */
.section-pricing {
  padding: 80px 0;
}

.section-header {
  text-align: center;
  margin-bottom: 40px;
}

.section-tag {
  font-size: 0.85rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--brand-accent);
  margin-bottom: 8px;
  display: block;
}

.section-title-h2 {
  font-size: 2.2rem;
  font-weight: 800;
  letter-spacing: -0.5px;
  color: var(--text-main);
  margin-bottom: 12px;
}

.billing-toggle-container {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  margin-top: 16px;
  padding: 6px;
  border: var(--black-border);
  border-radius: 999px;
  background: #FFFFFF;
}

.billing-btn {
  padding: 8px 20px;
  border-radius: 999px;
  border: none;
  font-weight: 700;
  font-size: 0.9rem;
  cursor: pointer;
  background: transparent;
  color: var(--text-muted);
  transition: var(--transition-fast);
}

.billing-btn.active {
  background: #000000;
  color: #FFFFFF;
}

.save-badge {
  background: #DC2626;
  color: #FFFFFF;
  font-size: 0.75rem;
  padding: 2px 8px;
  border-radius: 999px;
  font-weight: 800;
  margin-left: 4px;
}

/* Horizontal Swipeable Container for H2 */
.h2-pricing-controls {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 12px;
  margin-bottom: 16px;
}

.slider-btn {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  border: var(--black-border);
  background: #FFFFFF;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 1.2rem;
  font-weight: 700;
  transition: var(--transition-fast);
}

.slider-btn:hover {
  background: #000000;
  color: #FFFFFF;
}

.pricing-swipe-wrapper {
  display: flex;
  gap: 24px;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  padding: 12px 4px 32px;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
  scrollbar-color: #000000 #F1F5F9;
}

.pricing-swipe-wrapper::-webkit-scrollbar {
  height: 8px;
}
.pricing-swipe-wrapper::-webkit-scrollbar-track {
  background: #F1F5F9;
  border-radius: 999px;
}
.pricing-swipe-wrapper::-webkit-scrollbar-thumb {
  background: #000000;
  border-radius: 999px;
}

.pricing-card {
  flex: 0 0 320px;
  scroll-snap-align: start;
  border: var(--black-border);
  border-radius: var(--border-radius-lg);
  background: #FFFFFF;
  padding: 32px 24px;
  position: relative;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  box-shadow: var(--shadow-apple);
  transition: var(--transition-fast);
}

.pricing-card:hover {
  box-shadow: 6px 6px 0px #000000;
  transform: translateY(-4px);
}

.pricing-card.popular {
  border: var(--black-border-thick);
  background: #FAFAFA;
}

.popular-tag {
  position: absolute;
  top: -14px;
  right: 24px;
  background: #000000;
  color: #FFFFFF;
  font-size: 0.75rem;
  font-weight: 800;
  padding: 4px 14px;
  border-radius: 999px;
  border: 1px solid #FFFFFF;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.plan-name {
  font-size: 1.35rem;
  font-weight: 800;
  margin-bottom: 8px;
}

.plan-desc {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 20px;
  min-height: 40px;
}

.plan-price {
  font-size: 2.25rem;
  font-weight: 900;
  color: var(--text-main);
  margin-bottom: 24px;
}

.plan-price span.unit {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-muted);
}

.plan-features {
  list-style: none;
  margin-bottom: 32px;
}

.plan-features li {
  font-size: 0.9rem;
  padding: 8px 0;
  display: flex;
  align-items: center;
  gap: 10px;
  border-bottom: 1px stroke #E2E8F0;
}

.plan-features li .check {
  color: #10B981;
  font-weight: 900;
}

/* DIRECTIVE 5: H3 Articles Section - Vertical Top-to-Bottom Cyber Tech Scrollable Layout */
.section-articles {
  padding: 80px 0;
  background: #FFFFFF;
  border-top: var(--black-border);
  border-bottom: var(--black-border);
}

.section-title-h3 {
  font-size: 2.2rem;
  font-weight: 800;
  letter-spacing: -0.5px;
  color: var(--text-main);
  margin-bottom: 12px;
}

/* Cyber Tech Vertical Scroll Layout */
.tech-articles-container {
  display: grid;
  grid-template-columns: 300px 1fr;
  gap: 32px;
  margin-top: 40px;
  align-items: start;
}

@media (max-width: 900px) {
  .tech-articles-container {
    grid-template-columns: 1fr;
  }
}

.tech-timeline-sidebar {
  border: var(--black-border);
  border-radius: var(--border-radius-lg);
  padding: 24px;
  background: var(--bg-secondary);
  position: sticky;
  top: 96px;
}

.tech-sidebar-title {
  font-size: 1.1rem;
  font-weight: 800;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.tech-timeline-list {
  list-style: none;
  position: relative;
}

.tech-timeline-list::before {
  content: '';
  position: absolute;
  left: 11px;
  top: 10px;
  bottom: 10px;
  width: 2px;
  background: #CBD5E1;
}

.tech-timeline-item {
  position: relative;
  padding-left: 32px;
  margin-bottom: 20px;
  cursor: pointer;
}

.tech-timeline-dot {
  position: absolute;
  left: 6px;
  top: 6px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: #FFFFFF;
  border: 2px solid #64748B;
  transition: var(--transition-fast);
}

.tech-timeline-item.active .tech-timeline-dot {
  background: var(--brand-accent);
  border-color: #000000;
  box-shadow: 0 0 10px var(--brand-accent);
}

.tech-timeline-item-title {
  font-size: 0.88rem;
  font-weight: 700;
  color: var(--text-muted);
  transition: var(--transition-fast);
}

.tech-timeline-item.active .tech-timeline-item-title {
  color: #000000;
  font-weight: 800;
}

/* Top-to-Bottom Vertical Tech Stream */
.tech-vertical-stream {
  display: flex;
  flex-direction: column;
  gap: 24px;
  max-height: 680px;
  overflow-y: auto;
  padding-right: 8px;
  scrollbar-width: thin;
  scrollbar-color: #000000 #F1F5F9;
}

.tech-vertical-stream::-webkit-scrollbar {
  width: 8px;
}
.tech-vertical-stream::-webkit-scrollbar-track {
  background: #F1F5F9;
  border-radius: 999px;
}
.tech-vertical-stream::-webkit-scrollbar-thumb {
  background: #000000;
  border-radius: 999px;
}

.tech-article-card {
  border: var(--black-border);
  border-radius: var(--border-radius-lg);
  padding: 28px;
  background: #FFFFFF;
  position: relative;
  transition: var(--transition-fast);
}

.tech-article-card:hover {
  box-shadow: 6px 6px 0px #000000;
  transform: translateY(-2px);
}

.tech-badge-bar {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 12px;
}

.tech-badge {
  font-size: 0.75rem;
  font-weight: 800;
  padding: 4px 10px;
  border-radius: 999px;
  border: var(--black-border-thin);
  background: var(--bg-tertiary);
  color: var(--text-main);
}

.article-date {
  font-size: 0.8rem;
  color: var(--text-light);
}

.tech-article-title {
  font-size: 1.35rem;
  font-weight: 800;
  margin-bottom: 12px;
  line-height: 1.35;
}

.tech-article-excerpt {
  font-size: 0.95rem;
  color: var(--text-muted);
  margin-bottom: 20px;
  line-height: 1.6;
}

.article-keywords-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 20px;
}

.kw-tag {
  font-size: 0.75rem;
  font-weight: 600;
  padding: 3px 8px;
  background: #F1F5F9;
  border-radius: 4px;
  color: var(--brand-accent);
}

.article-link-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-weight: 700;
  font-size: 0.9rem;
  color: var(--brand-accent);
  transition: var(--transition-fast);
}

.article-link-btn:hover {
  color: var(--brand-accent-hover);
  text-decoration: underline;
}

/* DIRECTIVE 6: H4 User Reviews (Auto-jump) + Right Side Live Node Speed Test (Auto-refresh) */
.section-h4-reviews-speed {
  padding: 80px 0;
  background: var(--bg-secondary);
}

.h4-grid-wrapper {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
}

@media (max-width: 900px) {
  .h4-grid-wrapper {
    grid-template-columns: 1fr;
  }
}

.h4-card-panel {
  border: var(--black-border-thick);
  border-radius: var(--border-radius-lg);
  padding: 32px;
  background: #FFFFFF;
  box-shadow: var(--shadow-apple);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  min-height: 440px;
}

.section-title-h4 {
  font-size: 1.5rem;
  font-weight: 800;
  letter-spacing: -0.5px;
  margin-bottom: 20px;
  display: flex;
  align-items: center;
  gap: 10px;
}

/* Left: Auto Jumping Reviews */
.review-auto-wrapper {
  position: relative;
  flex-grow: 1;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.review-slide {
  opacity: 0;
  visibility: hidden;
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  transition: opacity 0.5s ease, transform 0.5s ease;
  transform: translateY(10px);
}

.review-slide.active {
  opacity: 1;
  visibility: visible;
  position: relative;
  transform: translateY(0);
}

.review-quote-box {
  background: var(--bg-secondary);
  border: var(--black-border-thin);
  border-radius: var(--border-radius-md);
  padding: 24px;
  margin-bottom: 20px;
  font-size: 1.05rem;
  line-height: 1.6;
  font-style: italic;
  color: var(--text-main);
  position: relative;
}

.review-user-info {
  display: flex;
  align-items: center;
  gap: 14px;
}

.review-avatar {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  border: var(--black-border-thin);
  background: #000000;
  color: #FFFFFF;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
}

.review-meta-name {
  font-weight: 800;
  font-size: 1rem;
}

.review-meta-role {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.review-stars {
  color: #F59E0B;
  font-size: 0.9rem;
  margin-top: 4px;
}

.review-dots-nav {
  display: flex;
  gap: 8px;
  margin-top: 24px;
  justify-content: center;
}

.dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  border: var(--black-border-thin);
  background: #CBD5E1;
  cursor: pointer;
  transition: var(--transition-fast);
}

.dot.active {
  background: #000000;
  width: 24px;
  border-radius: 999px;
}

/* Right: Auto Refreshing Speed Test Panel */
.speed-test-header-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 1px stroke #E2E8F0;
}

.live-indicator {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.8rem;
  font-weight: 800;
  color: #10B981;
  background: rgba(16, 185, 129, 0.1);
  padding: 4px 10px;
  border-radius: 999px;
  border: 1px solid #10B981;
}

.refresh-timer-spin {
  display: inline-block;
  animation: spin 3s linear infinite;
}

@keyframes spin {
  100% { transform: rotate(360deg); }
}

.speed-nodes-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.node-item-row {
  border: var(--black-border-thin);
  border-radius: var(--border-radius-md);
  padding: 14px 16px;
  background: var(--bg-secondary);
  display: flex;
  align-items: center;
  justify-content: space-between;
  transition: var(--transition-fast);
}

.node-flag-title {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 0.92rem;
}

.flag-icon {
  font-size: 1.2rem;
}

.node-metrics {
  display: flex;
  align-items: center;
  gap: 16px;
}

.ping-tag {
  font-size: 0.82rem;
  font-weight: 800;
  color: #10B981;
  background: #FFFFFF;
  padding: 2px 8px;
  border: 1px solid #10B981;
  border-radius: 4px;
}

.speed-meter-bar-outer {
  width: 100px;
  height: 8px;
  background: #E2E8F0;
  border-radius: 999px;
  overflow: hidden;
  position: relative;
}

.speed-meter-bar-inner {
  height: 100%;
  background: linear-gradient(90deg, #10B981 0%, #2563EB 100%);
  width: 85%;
  border-radius: 999px;
  transition: width 0.8s cubic-bezier(0.4, 0, 0.2, 1);
}

/* FAQ Section */
.section-faq {
  padding: 80px 0;
  background: #FFFFFF;
  border-top: var(--black-border);
}

.faq-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(450px, 1fr));
  gap: 24px;
  margin-top: 40px;
}

@media (max-width: 600px) {
  .faq-grid {
    grid-template-columns: 1fr;
  }
}

.faq-card {
  border: var(--black-border);
  border-radius: var(--border-radius-lg);
  padding: 24px;
  background: #FFFFFF;
}

.faq-q {
  font-size: 1.1rem;
  font-weight: 800;
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  gap: 8px;
}

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

/* CTA Banner Section */
.section-cta {
  padding: 80px 0;
  text-align: center;
}

.cta-box {
  border: var(--black-border-thick);
  border-radius: var(--border-radius-lg);
  padding: 60px 32px;
  background: #FFFFFF;
  box-shadow: 8px 8px 0px #000000;
}

.cta-title {
  font-size: 2.4rem;
  font-weight: 900;
  margin-bottom: 16px;
}

.cta-desc {
  font-size: 1.1rem;
  color: var(--text-muted);
  max-width: 680px;
  margin: 0 auto 32px;
}

/* Footer */
.footer {
  background: #000000;
  color: #FFFFFF;
  padding: 60px 0 30px;
  border-top: var(--black-border-thick);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr repeat(3, 1fr);
  gap: 40px;
  margin-bottom: 40px;
}

@media (max-width: 768px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}

.footer-brand-title {
  font-size: 1.4rem;
  font-weight: 800;
  margin-bottom: 12px;
  color: #FFFFFF;
}

.footer-brand-desc {
  font-size: 0.88rem;
  color: #94A3B8;
  max-width: 320px;
  line-height: 1.6;
}

.footer-col-title {
  font-size: 1rem;
  font-weight: 800;
  margin-bottom: 16px;
  color: #FFFFFF;
}

.footer-links-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-links-list a {
  font-size: 0.88rem;
  color: #94A3B8;
  transition: var(--transition-fast);
}

.footer-links-list a:hover {
  color: #FFFFFF;
  text-decoration: underline;
}

.footer-bottom {
  border-top: 1px solid #334155;
  padding-top: 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.82rem;
  color: #94A3B8;
  flex-wrap: wrap;
  gap: 16px;
}

/* Responsive fixes */
@media (max-width: 768px) {
  .hero-title-h1 {
    font-size: 2rem;
  }
  .section-title-h2, .section-title-h3 {
    font-size: 1.75rem;
  }
  .pricing-card {
    flex: 0 0 280px;
  }
  .nav-links {
    display: none;
  }
}