/* ==========================================================================
   XSUS 网络加速器 / 代理服务 - 霜月冷白 (Frost White) 极简奢华设计系统
   ========================================================================== */

:root {
  /* 颜色变量 - 霜月冷白主题 */
  --bg-primary: #f4f7fb;
  --bg-secondary: #ffffff;
  --bg-tertiary: #eef4fc;
  --bg-glass: rgba(255, 255, 255, 0.78);
  --bg-glass-hover: rgba(255, 255, 255, 0.96);
  
  --text-main: #0f172a;
  --text-muted: #334155;
  --text-light: #64748b;
  
  --accent-cyan: #0284c7;
  --accent-blue: #2563eb;
  --accent-teal: #06b6d4;
  --accent-gradient: linear-gradient(135deg, #0284c7 0%, #2563eb 50%, #4f46e5 100%);
  --frost-glow: 0 12px 36px -6px rgba(2, 132, 199, 0.28);
  
  --border-light: rgba(226, 232, 240, 0.85);
  --border-frost: rgba(255, 255, 255, 0.95);
  
  --shadow-sm: 0 4px 16px rgba(15, 23, 42, 0.03);
  --shadow-md: 0 12px 36px rgba(15, 23, 42, 0.06);
  --shadow-lg: 0 24px 56px rgba(15, 23, 42, 0.1);
  
  --radius-sm: 10px;
  --radius-md: 18px;
  --radius-lg: 28px;
  --radius-full: 9999px;
  
  --transition: all 0.35s cubic-bezier(0.16, 1, 0.3, 1);
}

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

html {
  scroll-behavior: smooth;
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Arial, sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-main);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

body {
  min-height: 100vh;
  overflow-x: hidden;
  background: 
    radial-gradient(circle at 15% 15%, rgba(2, 132, 199, 0.07) 0%, transparent 45%),
    radial-gradient(circle at 85% 75%, rgba(37, 99, 235, 0.07) 0%, transparent 45%),
    linear-gradient(180deg, #f8fafc 0%, #f1f5f9 100%);
  background-attachment: fixed;
}

a {
  color: inherit;
  text-decoration: none;
}

.container {
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 24px;
}

/* 导航栏 */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: 14px 0;
  background: rgba(244, 247, 251, 0.88);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-light);
  transition: var(--transition);
}

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

/* 头部 Logo */
.logo-btn {
  display: flex;
  align-items: center;
  gap: 12px;
  background: transparent;
  border: none;
  cursor: pointer;
  outline: none;
  padding: 6px 12px;
  border-radius: var(--radius-md);
  transition: var(--transition);
}

.logo-btn:hover {
  background: rgba(255, 255, 255, 0.9);
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}

.logo-btn:active {
  transform: scale(0.96);
}

.logo-icon {
  width: 40px;
  height: 40px;
  border-radius: 12px;
  background: var(--accent-gradient);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  box-shadow: var(--frost-glow);
  transition: var(--transition);
}

.logo-btn:hover .logo-icon {
  transform: rotate(-10deg) scale(1.08);
}

.logo-text {
  font-size: 24px;
  font-weight: 900;
  letter-spacing: -0.8px;
  background: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.logo-tag {
  font-size: 11px;
  font-weight: 800;
  padding: 3px 8px;
  border-radius: var(--radius-full);
  background: rgba(2, 132, 199, 0.12);
  color: var(--accent-cyan);
  margin-left: 4px;
  letter-spacing: 0.5px;
}

/* 页眉导航目录菜单 */
.header-nav {
  display: flex;
  align-items: center;
  gap: 24px;
}

.nav-link {
  font-size: 14px;
  font-weight: 700;
  color: var(--text-muted);
  transition: var(--transition);
  position: relative;
  padding: 4px 0;
}

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

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

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

.nav-actions {
  display: flex;
  align-items: center;
  gap: 16px;
}

/* CTA 按钮基础规范 */
.cta-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 28px;
  font-size: 15px;
  font-weight: 700;
  border-radius: var(--radius-full);
  transition: var(--transition);
  cursor: pointer;
  border: none;
  text-align: center;
  white-space: nowrap;
}

.cta-primary {
  background: var(--accent-gradient);
  color: #ffffff !important;
  box-shadow: 0 6px 24px rgba(2, 132, 199, 0.35);
}

.cta-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 32px rgba(2, 132, 199, 0.5);
  opacity: 0.96;
}

.cta-recommend {
  background: linear-gradient(135deg, #0284c7 0%, #06b6d4 100%);
  color: #ffffff !important;
  box-shadow: 0 6px 24px rgba(6, 182, 212, 0.35);
  border: 1px solid rgba(255, 255, 255, 0.5);
}

.cta-recommend:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 32px rgba(6, 182, 212, 0.5);
  opacity: 0.96;
}

.cta-secondary {
  background: rgba(255, 255, 255, 0.9);
  color: var(--text-main) !important;
  border: 1px solid var(--border-light);
  box-shadow: var(--shadow-sm);
}

.cta-secondary:hover {
  background: #ffffff;
  border-color: var(--accent-cyan);
  color: var(--accent-cyan) !important;
  transform: translateY(-2px);
}

/* 通用 Section */
.section {
  padding: 100px 0;
  position: relative;
}

.section-header {
  text-align: center;
  max-width: 760px;
  margin: 0 auto 60px;
}

.section-badge {
  display: inline-block;
  padding: 6px 18px;
  border-radius: var(--radius-full);
  background: rgba(2, 132, 199, 0.08);
  color: var(--accent-cyan);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0.8px;
  margin-bottom: 16px;
  text-transform: uppercase;
  border: 1px solid rgba(2, 132, 199, 0.18);
}

.section-title {
  font-size: 38px;
  font-weight: 900;
  line-height: 1.2;
  color: var(--text-main);
  margin-bottom: 16px;
  letter-spacing: -0.8px;
}

.section-subtitle {
  font-size: 17px;
  color: var(--text-muted);
  line-height: 1.7;
}

/* Hero 核心主视觉区 */
.hero {
  padding-top: 160px;
  padding-bottom: 80px;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr 1.05fr;
  gap: 50px;
  align-items: center;
}

.hero-content {
  text-align: left;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 18px;
  border-radius: var(--radius-full);
  background: rgba(255, 255, 255, 0.95);
  border: 1px solid var(--border-light);
  font-size: 13px;
  font-weight: 700;
  color: var(--text-muted);
  box-shadow: var(--shadow-sm);
  margin-bottom: 24px;
}

.hero-badge-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #10b981;
  box-shadow: 0 0 10px #10b981;
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.4; transform: scale(0.85); }
  100% { opacity: 1; transform: scale(1); }
}

.hero-title {
  font-size: 48px;
  font-weight: 900;
  line-height: 1.15;
  letter-spacing: -1.2px;
  color: var(--text-main);
  margin-bottom: 24px;
}

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

.hero-subtitle {
  font-size: 18px;
  color: var(--text-muted);
  margin-bottom: 36px;
  line-height: 1.7;
}

.hero-cta-group {
  display: flex;
  align-items: center;
  gap: 14px;
  flex-wrap: wrap;
  margin-bottom: 40px;
}

/* Hero 右侧动态图卡 */
.hero-visual {
  position: relative;
}

.visual-card-main {
  background: rgba(255, 255, 255, 0.9);
  border: 1px solid var(--border-frost);
  border-radius: var(--radius-lg);
  padding: 32px;
  box-shadow: var(--shadow-lg);
  backdrop-filter: blur(16px);
  position: relative;
  overflow: hidden;
}

.visual-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 24px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border-light);
}

.visual-title {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 16px;
  font-weight: 800;
  color: var(--text-main);
}

.visual-status-pill {
  font-size: 12px;
  font-weight: 700;
  padding: 4px 12px;
  border-radius: var(--radius-full);
  background: rgba(16, 185, 129, 0.12);
  color: #059669;
  display: flex;
  align-items: center;
  gap: 6px;
}

.speed-gauge-container {
  display: flex;
  align-items: center;
  justify-content: space-around;
  margin: 20px 0 28px;
  background: var(--bg-tertiary);
  padding: 24px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-light);
}

.speed-meter {
  text-align: center;
}

.meter-val {
  font-size: 36px;
  font-weight: 900;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  line-height: 1.1;
}

.meter-label {
  font-size: 12px;
  font-weight: 700;
  color: var(--text-light);
  margin-top: 4px;
  text-transform: uppercase;
}

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

.node-pulse-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: #ffffff;
  padding: 12px 18px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-light);
  transition: var(--transition);
}

.node-pulse-item:hover {
  transform: translateX(4px);
  border-color: var(--accent-cyan);
  box-shadow: var(--shadow-sm);
}

.node-info-group {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 14px;
  font-weight: 700;
}

.node-ping-badge {
  font-size: 12px;
  font-weight: 800;
  color: #10b981;
  background: rgba(16, 185, 129, 0.08);
  padding: 3px 10px;
  border-radius: var(--radius-full);
}

.float-badge {
  position: absolute;
  background: rgba(255, 255, 255, 0.95);
  border: 1px solid var(--border-frost);
  padding: 12px 20px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
  backdrop-filter: blur(12px);
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 13px;
  font-weight: 800;
  color: var(--text-main);
  animation: float 4s ease-in-out infinite;
  z-index: 2;
}

.float-badge-1 {
  top: -20px;
  right: -20px;
  animation-delay: 0s;
}

.float-badge-2 {
  bottom: -20px;
  left: -20px;
  animation-delay: 2s;
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-8px); }
}

.hero-stats-wrapper {
  margin-top: 60px;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  background: rgba(255, 255, 255, 0.88);
  padding: 28px 36px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-frost);
  box-shadow: var(--shadow-md);
  backdrop-filter: blur(14px);
}

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

.stat-num {
  font-size: 34px;
  font-weight: 900;
  color: var(--text-main);
  line-height: 1.1;
}

.stat-num span {
  font-size: 22px;
  color: var(--accent-cyan);
}

.stat-label {
  font-size: 13px;
  color: var(--text-light);
  font-weight: 700;
  margin-top: 4px;
}

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

.adv-card {
  background: rgba(255, 255, 255, 0.88);
  border: 1px solid var(--border-frost);
  border-radius: var(--radius-lg);
  padding: 44px 36px;
  transition: var(--transition);
  box-shadow: var(--shadow-sm);
  position: relative;
  overflow: hidden;
}

.adv-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: var(--accent-gradient);
  opacity: 0;
  transition: var(--transition);
}

.adv-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-lg);
  border-color: rgba(2, 132, 199, 0.35);
  background: #ffffff;
}

.adv-card:hover::before {
  opacity: 1;
}

.adv-icon-wrapper {
  width: 68px;
  height: 68px;
  border-radius: 20px;
  background: rgba(2, 132, 199, 0.08);
  color: var(--accent-cyan);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 28px;
  transition: var(--transition);
  border: 1px solid rgba(2, 132, 199, 0.15);
}

.adv-card:hover .adv-icon-wrapper {
  background: var(--accent-gradient);
  color: #ffffff;
  transform: scale(1.1) rotate(4deg);
  box-shadow: var(--frost-glow);
  border-color: transparent;
}

.adv-title {
  font-size: 22px;
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 14px;
}

.adv-desc {
  font-size: 15px;
  color: var(--text-muted);
  line-height: 1.8;
}

/* 流媒体与 AI 支持图卡 */
.support-section {
  background: linear-gradient(180deg, rgba(255,255,255,0.5) 0%, rgba(235,241,248,0.7) 100%);
  border-top: 1px solid var(--border-light);
  border-bottom: 1px solid var(--border-light);
}

.support-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.support-card {
  background: rgba(255, 255, 255, 0.92);
  border: 1px solid var(--border-frost);
  border-radius: var(--radius-md);
  padding: 24px 20px;
  display: flex;
  align-items: center;
  gap: 16px;
  transition: var(--transition);
  box-shadow: var(--shadow-sm);
  position: relative;
}

.support-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-md);
  border-color: var(--accent-cyan);
  background: #ffffff;
}

.support-icon-svg {
  width: 48px;
  height: 48px;
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  box-shadow: 0 4px 12px rgba(0,0,0,0.08);
}

.support-info h4 {
  font-size: 16px;
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 4px;
}

.support-info p {
  font-size: 12px;
  color: var(--text-light);
  font-weight: 600;
}

.support-tag-pill {
  font-size: 10px;
  font-weight: 800;
  padding: 2px 7px;
  border-radius: var(--radius-full);
  background: rgba(2, 132, 199, 0.08);
  color: var(--accent-cyan);
  display: inline-block;
  margin-top: 6px;
}

/* 套餐价格表 */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  align-items: stretch;
}

.price-card {
  background: rgba(255, 255, 255, 0.88);
  border: 1px solid var(--border-frost);
  border-radius: var(--radius-lg);
  padding: 36px 28px;
  display: flex;
  flex-direction: column;
  transition: var(--transition);
  box-shadow: var(--shadow-sm);
  position: relative;
}

.price-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
  background: #ffffff;
}

.price-card.featured {
  background: #ffffff;
  border: 2px solid var(--accent-cyan);
  box-shadow: var(--shadow-lg);
  transform: scale(1.02);
}

.price-card.featured:hover {
  transform: scale(1.04) translateY(-4px);
}

.popular-badge {
  position: absolute;
  top: -14px;
  right: 20px;
  background: var(--accent-gradient);
  color: #fff;
  font-size: 11px;
  font-weight: 800;
  padding: 4px 12px;
  border-radius: var(--radius-full);
  box-shadow: 0 4px 12px rgba(2, 132, 199, 0.35);
  letter-spacing: 0.5px;
}

.price-plan-name {
  font-size: 20px;
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 6px;
}

.price-plan-desc {
  font-size: 13px;
  color: var(--text-light);
  margin-bottom: 20px;
  min-height: 38px;
  line-height: 1.5;
}

.price-amount {
  font-size: 40px;
  font-weight: 900;
  color: var(--text-main);
  margin-bottom: 20px;
  display: flex;
  align-items: baseline;
  gap: 2px;
}

.price-currency {
  font-size: 22px;
  font-weight: 800;
  color: var(--accent-cyan);
}

.price-period {
  font-size: 13px;
  color: var(--text-light);
  font-weight: 600;
}

.price-features {
  list-style: none;
  margin-bottom: 28px;
  flex-grow: 1;
}

.price-features li {
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.price-features li svg {
  color: var(--accent-cyan);
  flex-shrink: 0;
}

.price-card .cta-btn {
  width: 100%;
}

/* SEO 文章图卡板块（放置在价格表正下方） */
.articles-section {
  background: linear-gradient(180deg, rgba(245,248,252,0.8) 0%, rgba(235,241,248,0.5) 100%);
  border-top: 1px solid var(--border-light);
  border-bottom: 1px solid var(--border-light);
}

.articles-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.article-card {
  background: rgba(255, 255, 255, 0.9);
  border: 1px solid var(--border-frost);
  border-radius: var(--radius-lg);
  padding: 32px 26px;
  display: flex;
  flex-direction: column;
  transition: var(--transition);
  box-shadow: var(--shadow-sm);
  position: relative;
}

.article-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
  background: #ffffff;
  border-color: rgba(2, 132, 199, 0.35);
}

.article-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 14px;
}

.article-card-tag {
  font-size: 11px;
  font-weight: 800;
  padding: 4px 10px;
  border-radius: var(--radius-full);
  background: rgba(2, 132, 199, 0.1);
  color: var(--accent-cyan);
  border: 1px solid rgba(2, 132, 199, 0.15);
}

.article-card-date {
  font-size: 12px;
  color: var(--text-light);
  font-weight: 600;
}

.article-card-title {
  font-size: 17px;
  font-weight: 800;
  color: var(--text-main);
  line-height: 1.45;
  margin-bottom: 12px;
  min-height: 48px;
}

.article-card-excerpt {
  font-size: 13px;
  color: var(--text-muted);
  line-height: 1.65;
  margin-bottom: 20px;
  flex-grow: 1;
}

.article-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  border-top: 1px solid var(--border-light);
  padding-top: 16px;
}

.btn-read-more {
  font-size: 13px;
  font-weight: 700;
  color: var(--accent-cyan);
  display: inline-flex;
  align-items: center;
  gap: 4px;
  transition: var(--transition);
}

.btn-read-more:hover {
  color: var(--accent-blue);
  transform: translateX(2px);
}

.btn-article-cta {
  font-size: 12px;
  font-weight: 800;
  padding: 7px 15px;
  border-radius: var(--radius-full);
  background: var(--accent-gradient);
  color: #ffffff !important;
  box-shadow: 0 4px 14px rgba(2, 132, 199, 0.25);
  transition: var(--transition);
}

.btn-article-cta:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 18px rgba(2, 132, 199, 0.4);
}

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

.testi-card {
  background: rgba(255, 255, 255, 0.88);
  border: 1px solid var(--border-frost);
  border-radius: var(--radius-lg);
  padding: 32px;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

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

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

.testi-avatar {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--bg-tertiary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  color: var(--accent-cyan);
  border: 2px solid var(--border-light);
}

.testi-name {
  font-size: 16px;
  font-weight: 800;
  color: var(--text-main);
}

.testi-role {
  font-size: 12px;
  color: var(--text-light);
}

.testi-stars {
  color: #f59e0b;
  margin-bottom: 14px;
  display: flex;
  gap: 4px;
}

.testi-content {
  font-size: 14px;
  color: var(--text-muted);
  line-height: 1.75;
}

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

.faq-item {
  background: rgba(255, 255, 255, 0.88);
  border: 1px solid var(--border-frost);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: var(--transition);
}

.faq-item:hover {
  border-color: rgba(2, 132, 199, 0.35);
}

.faq-question {
  width: 100%;
  padding: 22px 28px;
  background: transparent;
  border: none;
  text-align: left;
  font-size: 17px;
  font-weight: 800;
  color: var(--text-main);
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
}

.faq-icon {
  width: 22px;
  height: 22px;
  transition: transform 0.35s ease;
  color: var(--accent-cyan);
}

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

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s cubic-bezier(0, 1, 0, 1), padding 0.35s ease;
  padding: 0 28px;
  color: var(--text-muted);
  font-size: 15px;
  line-height: 1.8;
}

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

/* 页脚 Footer - 严格仅保留四个标题，在新页面打开 */
.footer {
  background: #0f172a;
  color: #f8fafc;
  padding: 60px 0 40px;
  margin-top: 60px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 36px;
  text-align: center;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.footer-brand .logo-icon {
  width: 36px;
  height: 36px;
}

.footer-brand-title {
  font-size: 20px;
  font-weight: 800;
  color: #ffffff;
}

.footer-nav-links {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 40px;
  flex-wrap: wrap;
}

.footer-nav-item {
  color: #cbd5e1;
  font-size: 16px;
  font-weight: 600;
  transition: var(--transition);
  padding: 6px 14px;
  border-radius: var(--radius-sm);
}

.footer-nav-item:hover {
  color: #38bdf8;
  background: rgba(255, 255, 255, 0.06);
}

.footer-copyright {
  font-size: 13px;
  color: #64748b;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding-top: 28px;
  width: 100%;
}

/* 右侧浮动章节上下切换箭头 */
.floating-arrows-nav {
  position: fixed;
  right: 24px;
  top: 50%;
  transform: translateY(-50%);
  z-index: 999;
  display: flex;
  flex-direction: column;
  gap: 12px;
  background: rgba(255, 255, 255, 0.88);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  padding: 10px 8px;
  border-radius: 30px;
  border: 1px solid var(--border-frost);
  box-shadow: 0 10px 30px rgba(15, 23, 42, 0.14);
  transition: var(--transition);
}

.arrow-btn {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: #ffffff;
  border: 1px solid var(--border-light);
  color: var(--text-main);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  outline: none;
  transition: var(--transition);
  box-shadow: var(--shadow-sm);
}

.arrow-btn:hover {
  background: var(--accent-gradient);
  color: #ffffff;
  border-color: transparent;
  transform: scale(1.12);
  box-shadow: var(--frost-glow);
}

.arrow-btn:active {
  transform: scale(0.92);
}

.arrow-btn:disabled {
  opacity: 0.35;
  cursor: not-allowed;
  transform: none !important;
}

.section-dots {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  padding: 4px 0;
}

.dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: #cbd5e1;
  transition: var(--transition);
  cursor: pointer;
}

.dot.active {
  background: var(--accent-cyan);
  height: 18px;
  border-radius: 10px;
}

/* 响应式媒体查询适配 (移动端优先) */
@media (max-width: 1100px) {
  .pricing-grid, .articles-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .support-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 992px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }
  .hero-content {
    text-align: center;
  }
  .hero-cta-group {
    justify-content: center;
  }
  .header-nav {
    display: none;
  }
  .advantages-grid, .testimonials-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .header {
    padding: 12px 0;
  }
  .logo-text {
    font-size: 20px;
  }
  .hero-title {
    font-size: 34px;
  }
  .hero-subtitle {
    font-size: 16px;
  }
  .pricing-grid, .advantages-grid, .testimonials-grid, .support-grid, .articles-grid {
    grid-template-columns: 1fr;
  }
  .hero-stats {
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
    padding: 20px;
  }
  .price-card.featured {
    transform: none;
  }
  .cta-btn {
    width: 100%;
  }
  .footer-nav-links {
    flex-direction: column;
    gap: 16px;
  }
  .floating-arrows-nav {
    right: 10px;
    padding: 8px 6px;
  }
  .arrow-btn {
    width: 38px;
    height: 38px;
  }
}