/* ==========================================================================
   老头VPN (laotouvpn.cyou) - 官方落地页主样式表
   主题：老头 Cyberpunk 暗黑渐变背景 + 左右边界 VPN 悬浮饰条
   ========================================================================== */

:root {
  --bg-primary: #08090e;
  --bg-secondary: #0f111a;
  --bg-card: rgba(18, 22, 36, 0.75);
  --bg-card-hover: rgba(30, 36, 58, 0.9);
  
  --accent-primary: #7952fb;
  --accent-secondary: #00f2fe;
  --accent-tertiary: #4facfe;
  --accent-glow: rgba(121, 82, 251, 0.4);
  --accent-gold: #ffb703;

  --text-main: #f0f2fe;
  --text-muted: #9499c3;
  --text-dim: #626894;
  
  --border-color: rgba(255, 255, 255, 0.08);
  --border-glow: rgba(121, 82, 251, 0.4);

  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --container-max-width: 1200px;
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;

  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* 基础重置 */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  font-family: var(--font-family);
  background-color: var(--bg-primary);
  color: var(--text-main);
  line-height: 1.6;
  overflow-x: hidden;
  position: relative;
  min-height: 100vh;
}

/* 老头科技元素背景叠加 */
.bg-laotou-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background-image: radial-gradient(circle at 50% 30%, rgba(10, 11, 16, 0.65) 0%, rgba(8, 9, 14, 0.95) 85%), url('../images/laotou_bg.jpg');
  background-size: cover;
  background-position: center top;
  background-repeat: no-repeat;
  opacity: 0.38;
  pointer-events: none;
  z-index: 0;
}

/* 背景酷炫光晕效果 */
.bg-glow-container {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  pointer-events: none;
  z-index: 0;
  overflow: hidden;
}

.bg-glow-1 {
  position: absolute;
  top: -10%;
  left: 20%;
  width: 50vw;
  height: 50vw;
  background: radial-gradient(circle, rgba(121, 82, 251, 0.22) 0%, rgba(0,0,0,0) 70%);
  filter: blur(90px);
  animation: pulse-glow 10s infinite alternate ease-in-out;
}

.bg-glow-2 {
  position: absolute;
  top: 40%;
  right: -10%;
  width: 45vw;
  height: 45vw;
  background: radial-gradient(circle, rgba(0, 242, 254, 0.16) 0%, rgba(0,0,0,0) 70%);
  filter: blur(100px);
  animation: pulse-glow 14s infinite alternate-reverse ease-in-out;
}

@keyframes pulse-glow {
  0% { transform: scale(1) translate(0, 0); opacity: 0.7; }
  100% { transform: scale(1.15) translate(-30px, 30px); opacity: 1; }
}

/* Canvas 鼠标尾翼层 */
#cursor-canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 9999;
}

/* 左右边界 VPN 悬浮挂件 (Side Gutters for Desktop) */
.side-gutter {
  position: fixed;
  top: 130px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  z-index: 90;
  pointer-events: none; /* 让鼠标穿透，不遮挡主内容 */
}

.side-gutter.side-left {
  left: 16px;
}

.side-gutter.side-right {
  right: 16px;
}

.gutter-badge {
  pointer-events: auto;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  background: rgba(18, 22, 36, 0.75);
  border: 1px solid var(--border-glow);
  border-radius: 30px;
  backdrop-filter: blur(12px);
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--text-main);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.4);
  transition: var(--transition-normal);
  animation: float-badge 6s infinite alternate ease-in-out;
}

.side-left .gutter-badge:nth-child(even), .side-right .gutter-badge:nth-child(odd) {
  animation-delay: -3s;
}

@keyframes float-badge {
  0% { transform: translateY(0px); }
  100% { transform: translateY(-8px); }
}

.gutter-badge:hover {
  background: rgba(30, 36, 58, 0.95);
  border-color: var(--accent-secondary);
  box-shadow: 0 10px 30px rgba(0, 242, 254, 0.3);
  transform: scale(1.05);
}

.status-dot {
  width: 8px;
  height: 8px;
  background-color: #10b981;
  border-radius: 50%;
  box-shadow: 0 0 10px #10b981;
  flex-shrink: 0;
}

.status-dot.pulse {
  animation: pulse-dot 1.8s infinite;
}

@keyframes pulse-dot {
  0% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.7); }
  70% { transform: scale(1.2); box-shadow: 0 0 0 8px rgba(16, 185, 129, 0); }
  100% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(16, 185, 129, 0); }
}

/* 布局容器 */
.container {
  max-width: var(--container-max-width);
  margin: 0 auto;
  padding: 0 24px;
  position: relative;
  z-index: 1;
}

/* 导航栏 Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(8, 9, 14, 0.88);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-color);
  padding: 14px 0;
}

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

.logo {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--text-main);
  font-weight: 800;
  font-size: 1.5rem;
  letter-spacing: -0.5px;
}

.logo-icon-img {
  width: 42px;
  height: 42px;
  border-radius: var(--radius-sm);
  filter: drop-shadow(0 0 12px var(--accent-glow));
}

.logo-text span {
  color: var(--accent-secondary);
}

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

.nav-links a {
  color: var(--text-muted);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.95rem;
  transition: var(--transition-fast);
}

.nav-links a:hover {
  color: var(--accent-secondary);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 14px;
}

/* 移动端菜单按钮 */
.mobile-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text-main);
  font-size: 1.8rem;
  cursor: pointer;
}

/* 按钮基础样式 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
  transition: var(--transition-normal);
  cursor: pointer;
  border: 1px solid transparent;
  white-space: nowrap;
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent-primary), #6038f5);
  color: #fff;
  box-shadow: 0 4px 20px var(--accent-glow);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(121, 82, 251, 0.6);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.05);
  color: var(--text-main);
  border-color: var(--border-color);
  backdrop-filter: blur(10px);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: var(--accent-secondary);
  color: var(--accent-secondary);
  transform: translateY(-2px);
}

.btn-recommend {
  background: linear-gradient(135deg, #00c6ff, #0072ff);
  color: #fff;
  box-shadow: 0 4px 20px rgba(0, 198, 255, 0.3);
}

.btn-recommend:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(0, 198, 255, 0.6);
}

.btn-lg {
  padding: 16px 36px;
  font-size: 1.1rem;
  border-radius: var(--radius-md);
}

/* Hero 英雄区 */
.hero-section {
  padding: 90px 0 60px;
  text-align: center;
}

.badge-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  background: rgba(121, 82, 251, 0.15);
  border: 1px solid rgba(121, 82, 251, 0.4);
  border-radius: 50px;
  color: var(--accent-secondary);
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 24px;
}

.hero-title {
  font-size: 3.5rem;
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 24px;
  letter-spacing: -1px;
}

.text-gradient {
  background: linear-gradient(135deg, #ffffff 0%, var(--accent-secondary) 50%, var(--accent-primary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--text-muted);
  max-width: 760px;
  margin: 0 auto 40px;
  line-height: 1.7;
}

.hero-cta-group {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 20px;
  flex-wrap: wrap;
  margin-bottom: 48px;
}

/* 极速状态指标 */
.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  max-width: 900px;
  margin: 0 auto;
  padding: 24px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  backdrop-filter: blur(12px);
}

.stat-item {
  text-align: center;
}

.stat-value {
  font-size: 1.8rem;
  font-weight: 800;
  color: var(--accent-secondary);
}

.stat-label {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-top: 4px;
}

/* 通用 Section 样式 */
.section {
  padding: 80px 0;
}

.section-header {
  text-align: center;
  max-width: 700px;
  margin: 0 auto 50px;
}

.section-title {
  font-size: 2.3rem;
  font-weight: 700;
  margin-bottom: 16px;
  letter-spacing: -0.5px;
}

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

/* 核心优势 Grid */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 32px;
  transition: var(--transition-normal);
  backdrop-filter: blur(10px);
}

.feature-card:hover {
  transform: translateY(-6px);
  border-color: var(--border-glow);
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.4);
  background: var(--bg-card-hover);
}

.feature-icon {
  width: 54px;
  height: 54px;
  background: rgba(121, 82, 251, 0.15);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  color: var(--accent-secondary);
}

.feature-icon svg {
  width: 28px;
  height: 28px;
  fill: currentColor;
}

.feature-card h3 {
  font-size: 1.3rem;
  margin-bottom: 12px;
}

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

/* 套餐卡片：一排横向布局 (Pricing Section - Single Row) */
.pricing-section {
  position: relative;
}

.pricing-row {
  display: flex;
  flex-direction: row;
  justify-content: center;
  align-items: stretch;
  gap: 20px;
  width: 100%;
}

.pricing-card {
  flex: 1;
  min-width: 0;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 32px 20px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  position: relative;
  transition: var(--transition-normal);
  backdrop-filter: blur(12px);
}

.pricing-card:hover {
  transform: translateY(-8px);
  border-color: var(--accent-secondary);
  box-shadow: 0 16px 40px rgba(0, 242, 254, 0.15);
}

.pricing-card.popular {
  background: linear-gradient(180deg, rgba(35, 28, 65, 0.9) 0%, rgba(18, 20, 32, 0.9) 100%);
  border: 2px solid var(--accent-primary);
  box-shadow: 0 8px 30px rgba(121, 82, 251, 0.3);
}

.pricing-card.popular:hover {
  box-shadow: 0 16px 50px rgba(121, 82, 251, 0.5);
}

.popular-badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: linear-gradient(90deg, var(--accent-primary), var(--accent-secondary));
  color: #fff;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 4px 16px;
  border-radius: 50px;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.pricing-header {
  text-align: center;
  margin-bottom: 24px;
}

.pricing-title {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 12px;
}

.pricing-price {
  font-size: 2.1rem;
  font-weight: 800;
  color: var(--text-main);
}

.pricing-price span {
  font-size: 0.85rem;
  color: var(--text-muted);
  font-weight: 400;
}

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

.pricing-features li {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-bottom: 12px;
}

.pricing-features svg {
  width: 16px;
  height: 16px;
  fill: var(--accent-secondary);
  flex-shrink: 0;
}

/* 关联 SEO 文章区 */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.article-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 28px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: var(--transition-normal);
}

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

.article-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 0.8rem;
  color: var(--accent-secondary);
  margin-bottom: 12px;
}

.article-title {
  font-size: 1.15rem;
  font-weight: 700;
  line-height: 1.4;
  margin-bottom: 12px;
}

.article-title a {
  color: var(--text-main);
  text-decoration: none;
  transition: var(--transition-fast);
}

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

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

.article-link {
  color: var(--accent-tertiary);
  text-decoration: none;
  font-size: 0.88rem;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.article-link:hover {
  color: var(--accent-secondary);
}

/* 用户评价 Testimonials */
.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.testimonial-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 28px;
  backdrop-filter: blur(10px);
}

.user-profile {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 16px;
}

.user-avatar {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  color: #fff;
  font-size: 1.1rem;
}

.user-info h4 {
  font-size: 1rem;
  font-weight: 600;
}

.user-info span {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.rating {
  color: var(--accent-gold);
  margin-bottom: 12px;
  font-size: 0.9rem;
}

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

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

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

.faq-question {
  padding: 20px 28px;
  font-size: 1.05rem;
  font-weight: 600;
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  user-select: none;
}

.faq-toggle-icon {
  width: 20px;
  height: 20px;
  transition: transform 0.3s ease;
  fill: var(--text-muted);
}

.faq-item.active .faq-toggle-icon {
  transform: rotate(180deg);
  fill: var(--accent-secondary);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s cubic-bezier(0.4, 0, 0.2, 1), padding 0.3s ease;
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.7;
  padding: 0 28px;
}

.faq-item.active .faq-answer {
  max-height: 300px;
  padding: 0 28px 24px 28px;
}

/* 页脚与 PBN 友情链接核心样式 */
.site-footer {
  background: #050609;
  border-top: 1px solid var(--border-color);
  padding: 60px 0 24px;
  font-size: 0.9rem;
  color: var(--text-muted);
  position: relative;
  z-index: 10;
}

.footer-content {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 40px;
}

.footer-col h4 {
  color: var(--text-main);
  font-size: 1rem;
  margin-bottom: 20px;
}

.footer-links {
  list-style: none;
}

.footer-links li {
  margin-bottom: 10px;
}

.footer-links a {
  color: var(--text-muted);
  text-decoration: none;
  transition: var(--transition-fast);
}

.footer-links a:hover {
  color: var(--accent-secondary);
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  padding-top: 24px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  text-align: center;
}

/* PBN 友情链接区 (低调、美观、融合样式，对应图2 机场测评) */
.footer-pbn-container {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
  font-size: 0.82rem;
  color: var(--text-dim);
  padding: 12px 20px;
  background: rgba(255, 255, 255, 0.02);
  border-radius: var(--radius-sm);
  border: 1px solid rgba(255, 255, 255, 0.03);
}

.footer-pbn-title {
  color: var(--text-dim);
  font-weight: 500;
}

.footer-pbn-link {
  color: var(--text-muted);
  text-decoration: none;
  transition: var(--transition-fast);
  padding: 2px 8px;
  border-radius: 4px;
}

.footer-pbn-link:hover {
  color: var(--accent-secondary);
  background: rgba(121, 82, 251, 0.1);
}

/* 文章详情页专用样式 */
.article-page {
  padding: 60px 0 100px;
}

.article-container {
  max-width: 860px;
  margin: 0 auto;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 48px;
  backdrop-filter: blur(12px);
}

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

.article-body h1 {
  font-size: 2.2rem;
  color: var(--text-main);
  margin-bottom: 20px;
  line-height: 1.3;
}

.article-body h2 {
  font-size: 1.6rem;
  color: var(--accent-secondary);
  margin: 36px 0 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-color);
}

.article-body h3 {
  font-size: 1.25rem;
  color: var(--text-main);
  margin: 24px 0 12px;
}

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

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

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

.article-cta-box {
  margin: 40px 0;
  padding: 28px;
  background: linear-gradient(135deg, rgba(121, 82, 251, 0.15), rgba(0, 242, 254, 0.15));
  border: 1px solid var(--border-glow);
  border-radius: var(--radius-md);
  text-align: center;
}

.article-cta-box h3 {
  color: var(--text-main);
  font-size: 1.4rem;
  margin-bottom: 12px;
}

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

/* 响应式媒体查询 Mobile Responsiveness */
@media (max-width: 1540px) {
  /* 窄屏下隐藏侧边栏饰条，防止遮挡内容 */
  .side-gutter {
    display: none;
  }
}

@media (max-width: 1024px) {
  .hero-title {
    font-size: 2.8rem;
  }
  
  .pricing-row {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
  }

  .features-grid, .articles-grid, .testimonials-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .footer-content {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  .nav-links, .nav-actions .btn {
    display: none;
  }

  .mobile-toggle {
    display: block;
  }

  .nav-links.active {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    background: var(--bg-secondary);
    padding: 24px;
    border-bottom: 1px solid var(--border-color);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
  }

  .hero-title {
    font-size: 2.1rem;
  }

  .hero-subtitle {
    font-size: 1rem;
  }

  .hero-stats {
    grid-template-columns: repeat(2, 1fr);
  }

  .pricing-row {
    grid-template-columns: 1fr;
    max-width: 420px;
    margin: 0 auto;
  }

  .features-grid, .articles-grid, .testimonials-grid {
    grid-template-columns: 1fr;
  }

  .footer-content {
    grid-template-columns: 1fr;
  }

  .article-container {
    padding: 24px;
  }
  
  .article-body h1 {
    font-size: 1.7rem;
  }
}