/* ==========================================================================
   XSUS (xsusvpn.xyz) - 全局 CSS 样式表
   Design: Cyber Cyberpunk Dark Theme / Modern Glassmorphism
   ========================================================================== */

:root {
  --bg-dark: #070913;
  --bg-card: rgba(18, 22, 41, 0.75);
  --bg-card-hover: rgba(27, 33, 62, 0.85);
  --border-color: rgba(139, 92, 246, 0.2);
  --border-glow: rgba(236, 72, 153, 0.4);
  
  --primary: #8b5cf6;
  --primary-hover: #7c3aed;
  --secondary: #ec4899;
  --accent: #06b6d4;
  --success: #10b981;
  --warning: #f59e0b;
  
  --text-main: #f3f4f6;
  --text-muted: #9ca3af;
  --text-dim: #6b7280;
  
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji";
  --container-max: 1200px;
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --shadow-glow: 0 0 25px rgba(139, 92, 246, 0.25);
  --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 {
  background-color: var(--bg-dark);
  background-image: 
    radial-gradient(circle at 15% 15%, rgba(139, 92, 246, 0.15) 0%, transparent 40%),
    radial-gradient(circle at 85% 65%, rgba(236, 72, 153, 0.12) 0%, transparent 45%),
    radial-gradient(circle at 50% 90%, rgba(6, 182, 212, 0.1) 0%, transparent 50%);
  background-attachment: fixed;
  color: var(--text-main);
  font-family: var(--font-family);
  line-height: 1.6;
  overflow-x: hidden;
}

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

a:hover {
  color: #67e8f9;
}

.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 20px;
}

.text-gradient {
  background: linear-gradient(135deg, #a855f7 0%, #ec4899 50%, #3b82f6 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.text-gradient-cyan {
  background: linear-gradient(135deg, #06b6d4 0%, #3b82f6 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* Glassmorphism Panel */
.glass-panel {
  background: var(--bg-card);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
  transition: var(--transition);
}

.glass-panel:hover {
  border-color: rgba(168, 85, 247, 0.4);
  box-shadow: 0 12px 40px 0 rgba(139, 92, 246, 0.2);
}

/* Buttons */
.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  background: linear-gradient(135deg, #8b5cf6 0%, #ec4899 100%);
  color: #ffffff;
  font-weight: 700;
  padding: 12px 28px;
  border-radius: 50px;
  border: none;
  cursor: pointer;
  box-shadow: 0 4px 20px rgba(236, 72, 153, 0.35);
  transition: var(--transition);
  text-decoration: none;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 28px rgba(236, 72, 153, 0.55);
  color: #ffffff;
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  background: rgba(255, 255, 255, 0.05);
  color: var(--text-main);
  font-weight: 600;
  padding: 12px 26px;
  border-radius: 50px;
  border: 1px solid rgba(255, 255, 255, 0.15);
  cursor: pointer;
  transition: var(--transition);
  text-decoration: none;
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.12);
  border-color: var(--primary);
  color: #ffffff;
}

/* Navigation Header */
.header-nav {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(7, 9, 19, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  padding: 14px 0;
}

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

.logo-link {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
}

.logo-img {
  width: 40px;
  height: 40px;
  border-radius: 10px;
}

.logo-text {
  font-size: 1.4rem;
  font-weight: 800;
  color: #ffffff;
  letter-spacing: -0.5px;
}

.logo-badge {
  background: rgba(139, 92, 246, 0.18);
  border: 1px solid rgba(139, 92, 246, 0.4);
  color: #c084fc;
  font-size: 0.72rem;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: 20px;
}

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

.nav-links a {
  color: var(--text-muted);
  font-weight: 500;
  font-size: 0.95rem;
}

.nav-links a:hover {
  color: #ffffff;
}

.mobile-menu-toggle {
  display: none;
  background: none;
  border: none;
  color: #ffffff;
  font-size: 1.6rem;
  cursor: pointer;
}

/* Mobile Drawer Menu */
.mobile-nav-drawer {
  display: none;
  position: fixed;
  top: 69px;
  left: 0;
  width: 100%;
  background: rgba(11, 15, 25, 0.96);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-color);
  padding: 20px;
  z-index: 999;
}

.mobile-nav-drawer.active {
  display: block;
}

.mobile-nav-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.mobile-nav-links a {
  font-size: 1.05rem;
  color: var(--text-main);
  display: block;
}

/* Hero Section */
.hero-section {
  padding: 90px 0 60px;
}

.hero-layout-grid {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 40px;
  align-items: center;
}

.hero-badge-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(236, 72, 153, 0.12);
  border: 1px solid rgba(236, 72, 153, 0.35);
  color: #f472b6;
  font-size: 0.85rem;
  font-weight: 700;
  padding: 6px 16px;
  border-radius: 50px;
  margin-bottom: 20px;
}

.hero-title {
  font-size: 3.1rem;
  line-height: 1.15;
  font-weight: 900;
  margin-bottom: 22px;
  letter-spacing: -1px;
}

.hero-subtitle {
  font-size: 1.12rem;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 32px;
}

.hero-cta-group {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}

/* Status Panel (Right of Hero) */
.hero-right-card {
  padding: 28px;
}

.hero-right-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  padding-bottom: 16px;
  margin-bottom: 20px;
}

.status-indicator {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--success);
  font-size: 0.88rem;
  font-weight: 600;
}

.pulse-dot {
  width: 10px;
  height: 10px;
  background-color: var(--success);
  border-radius: 50%;
  box-shadow: 0 0 10px var(--success);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.7); }
  70% { transform: scale(1); box-shadow: 0 0 0 10px rgba(16, 185, 129, 0); }
  100% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(16, 185, 129, 0); }
}

.spec-list {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.spec-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: rgba(255, 255, 255, 0.03);
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(255, 255, 255, 0.05);
}

.spec-label {
  color: var(--text-muted);
  font-size: 0.9rem;
}

.spec-val {
  color: var(--text-main);
  font-weight: 700;
  font-size: 0.95rem;
}

/* General Section Structure */
.section-padding {
  padding: 80px 0;
}

.section-header {
  text-align: center;
  max-width: 750px;
  margin: 0 auto 50px;
}

.section-tag {
  color: var(--accent);
  text-transform: uppercase;
  font-size: 0.82rem;
  font-weight: 800;
  letter-spacing: 1.5px;
  display: block;
  margin-bottom: 8px;
}

.section-title {
  font-size: 2.2rem;
  font-weight: 800;
  line-height: 1.25;
  margin-bottom: 14px;
}

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

/* Ping Test Simulator */
.ping-container {
  padding: 30px;
}

.ping-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 16px;
}

.ping-card-item {
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-radius: var(--radius-sm);
  padding: 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

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

.flag-icon {
  font-size: 1.6rem;
}

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

.node-sub {
  font-size: 0.78rem;
  color: var(--text-muted);
}

.ping-right-badge {
  text-align: right;
}

.ping-val {
  font-size: 0.95rem;
  font-weight: 800;
  color: var(--success);
}

.ping-bar-bg {
  width: 60px;
  height: 5px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 10px;
  margin-top: 4px;
  overflow: hidden;
}

.ping-bar-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--success), var(--accent));
  border-radius: 10px;
  transition: width 0.5s ease;
}

/* Features Grid */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 24px;
}

.feature-box {
  padding: 32px 26px;
}

.feature-box-icon {
  font-size: 2.2rem;
  margin-bottom: 18px;
  display: inline-block;
  background: rgba(139, 92, 246, 0.12);
  width: 60px;
  height: 60px;
  line-height: 60px;
  text-align: center;
  border-radius: 16px;
  border: 1px solid rgba(139, 92, 246, 0.3);
}

.feature-box h3 {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 10px;
  color: #ffffff;
}

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

/* Pricing Section */
.pricing-matrix {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 24px;
  align-items: stretch;
}

.pricing-card {
  padding: 32px 24px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  position: relative;
}

.pricing-card.recommended {
  border-color: var(--secondary);
  background: linear-gradient(180deg, rgba(236, 72, 153, 0.15) 0%, rgba(18, 22, 41, 0.85) 100%);
  box-shadow: 0 0 35px rgba(236, 72, 153, 0.25);
  transform: scale(1.03);
}

.badge-ribbon {
  position: absolute;
  top: -12px;
  right: 20px;
  background: linear-gradient(135deg, #ec4899, #8b5cf6);
  color: #ffffff;
  font-size: 0.75rem;
  font-weight: 800;
  padding: 4px 12px;
  border-radius: 20px;
  letter-spacing: 0.5px;
}

.card-title {
  font-size: 1.3rem;
  font-weight: 800;
  margin-bottom: 6px;
}

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

.card-price-row {
  margin-bottom: 24px;
}

.price-num {
  font-size: 2.6rem;
  font-weight: 900;
  color: #ffffff;
}

.price-unit {
  font-size: 0.95rem;
  color: var(--text-muted);
  font-weight: 400;
}

.feature-check-list {
  list-style: none;
  margin-bottom: 30px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.feature-check-list li {
  font-size: 0.9rem;
  color: var(--text-main);
  display: flex;
  align-items: center;
  gap: 10px;
}

.feature-check-list svg {
  width: 18px;
  height: 18px;
  fill: var(--success);
  flex-shrink: 0;
}

/* User Reviews / Testimonials Section */
.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
}

.testimonial-card {
  padding: 24px;
}

.user-profile {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 14px;
}

.avatar-circle {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  color: #ffffff;
  font-size: 1.1rem;
}

.user-name {
  font-weight: 700;
  font-size: 1rem;
}

.user-tag {
  font-size: 0.78rem;
  color: var(--text-muted);
}

.star-rating {
  color: #fbbf24;
  font-size: 0.9rem;
  margin-bottom: 10px;
}

.comment-text {
  color: var(--text-muted);
  font-size: 0.92rem;
  line-height: 1.6;
}

/* FAQ Accordion */
.faq-accordion {
  max-width: 840px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

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

.faq-question {
  width: 100%;
  padding: 20px 24px;
  text-align: left;
  background: none;
  border: none;
  color: #ffffff;
  font-size: 1.05rem;
  font-weight: 700;
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
}

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

.faq-arrow {
  font-size: 1.2rem;
  transition: transform 0.3s ease;
}

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

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s cubic-bezier(0, 1, 0, 1);
  background: rgba(0, 0, 0, 0.2);
}

.faq-answer-inner {
  padding: 0 24px 20px;
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.7;
}

/* Articles Section */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 24px;
}

.article-card {
  padding: 26px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.article-date {
  font-size: 0.78rem;
  color: var(--accent);
  font-weight: 700;
  margin-bottom: 8px;
  display: block;
}

.article-card h3 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 12px;
  line-height: 1.4;
  color: #ffffff;
}

.article-excerpt {
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-bottom: 20px;
  line-height: 1.6;
}

.article-link {
  font-weight: 700;
  font-size: 0.9rem;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

/* Article Page Details */
.article-detail-container {
  max-width: 900px;
  margin: 40px auto 80px;
  padding: 40px;
}

.article-detail-header {
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  padding-bottom: 24px;
  margin-bottom: 32px;
}

.breadcrumb {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 16px;
}

.breadcrumb a {
  color: var(--text-muted);
}

.breadcrumb a:hover {
  color: var(--accent);
}

.article-title-main {
  font-size: 2.3rem;
  font-weight: 900;
  line-height: 1.25;
  margin-bottom: 16px;
}

.article-meta-bar {
  display: flex;
  align-items: center;
  gap: 20px;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.article-body-content {
  font-size: 1.05rem;
  line-height: 1.85;
  color: #d1d5db;
}

.article-body-content h2 {
  font-size: 1.6rem;
  font-weight: 800;
  color: #ffffff;
  margin: 40px 0 18px;
  border-left: 4px solid var(--primary);
  padding-left: 14px;
}

.article-body-content h3 {
  font-size: 1.25rem;
  font-weight: 700;
  color: #f3f4f6;
  margin: 28px 0 14px;
}

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

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

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

.article-cta-box {
  background: linear-gradient(135deg, rgba(139, 92, 246, 0.2), rgba(236, 72, 153, 0.2));
  border: 1px solid rgba(236, 72, 153, 0.4);
  border-radius: var(--radius-md);
  padding: 30px;
  text-align: center;
  margin: 40px 0;
}

.article-cta-box h3 {
  font-size: 1.4rem;
  margin-bottom: 10px;
  color: #ffffff;
}

.article-cta-box p {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin-bottom: 20px;
}

/* Footer & PBN Links Section */
footer {
  background: rgba(4, 6, 12, 0.95);
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding: 60px 0 30px;
  margin-top: 60px;
}

.footer-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 24px;
}

.footer-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.3rem;
  font-weight: 800;
  color: #ffffff;
}

.footer-nav-links {
  display: flex;
  gap: 20px;
  flex-wrap: wrap;
  justify-content: center;
  list-style: none;
}

.footer-nav-links a {
  color: var(--text-muted);
  font-size: 0.9rem;
}

.footer-nav-links a:hover {
  color: #ffffff;
}

/* Core Task 2: PBN Friend Links Styling */
.friendly-links-container {
  margin-top: 24px;
  padding-top: 20px;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
}

.friendly-links-label {
  font-size: 0.78rem;
  color: var(--text-dim);
  font-weight: 600;
}

.friendly-link-item {
  font-size: 0.8rem;
  color: var(--text-muted);
  text-decoration: none;
  transition: var(--transition);
  opacity: 0.75;
}

.friendly-link-item:hover {
  color: var(--accent);
  opacity: 1;
  text-decoration: underline;
}

.friendly-link-divider {
  color: var(--text-dim);
  font-size: 0.75rem;
}

.copyright-text {
  font-size: 0.82rem;
  color: var(--text-dim);
  margin-top: 10px;
}

/* Responsive Queries */
@media (max-width: 992px) {
  .hero-layout-grid {
    grid-template-columns: 1fr;
    gap: 30px;
  }
  
  .hero-title {
    font-size: 2.4rem;
  }
  
  .pricing-card.recommended {
    transform: none;
  }
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
  }
  
  .mobile-menu-toggle {
    display: block;
  }
  
  .section-title {
    font-size: 1.8rem;
  }
  
  .hero-title {
    font-size: 2rem;
  }

  .article-detail-container {
    padding: 24px 18px;
  }
  
  .article-title-main {
    font-size: 1.7rem;
  }
}