/* ==========================================================================
   星维机场 Set 3 - 环域分区系统 官方样式表
   配景色调: 雾灰 (#F5F4F2) + 紫灰 (#6B667C) + 鼠尾草绿 (#747E6E) + 铜色 (#A87555)
   气质定位: 知识型 · 编辑型 · 克制 · 成熟 · 安静 · 可信
   ========================================================================== */

:root {
  --bg: #F5F4F2;
  --surface: #FFFFFF;
  --surface-warm: #F3F0ED;
  --text: #252429;
  --body-text: #626067;
  --muted: #8A878E;
  
  --violet-gray: #6B667C;
  --dark-violet-gray: #514D63;
  --light-violet-gray: #ECEAF0;
  
  --sage: #747E6E;
  --dark-sage: #596255;
  --light-sage: #EDF0EA;
  
  --copper: #A87555;
  --dark-copper: #895D43;
  
  --warm-gray: #EEEAE6;
  --light-warm-gray: #F3F0ED;
  
  --border: #DCD9DD;
  --border-subtle: #CCC8CF;
  
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 10px;
  
  --shadow-subtle: 0 10px 28px rgba(37, 36, 41, 0.025);
  
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
  --max-width: 1200px;
  --article-max-width: 800px;
}

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

html {
  font-family: var(--font-family);
  font-size: 16px;
  line-height: 1.8;
  color: var(--body-text);
  background-color: var(--bg);
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
}

body {
  overflow-x: hidden;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Accessibility focus styles */
:focus-visible {
  outline: 2px solid var(--violet-gray);
  outline-offset: 3px;
}

a {
  color: var(--dark-violet-gray);
  text-decoration: none;
  transition: color 0.2s ease, opacity 0.2s ease;
}

a:hover {
  color: var(--copper);
}

p {
  margin-bottom: 1.25rem;
}

h1, h2, h3, h4, h5, h6 {
  color: var(--text);
  font-weight: 600;
  line-height: 1.35;
  letter-spacing: -0.02em;
}

h1 {
  font-size: clamp(2.25rem, 4vw, 3.5rem);
  margin-bottom: 1.25rem;
}

h2 {
  font-size: clamp(1.65rem, 2.8vw, 2.25rem);
  margin-bottom: 1rem;
}

h3 {
  font-size: clamp(1.2rem, 2vw, 1.5rem);
  margin-bottom: 0.75rem;
}

ul, ol {
  padding-left: 1.5rem;
  margin-bottom: 1.25rem;
}

li {
  margin-bottom: 0.5rem;
}

/* Header Navbar */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: 72px;
  background-color: rgba(245, 244, 242, 0.95);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
}

.header-inner {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand-logo-wrap {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.brand-logo-svg {
  width: 36px;
  height: 36px;
  flex-shrink: 0;
}

.brand-title-group {
  display: flex;
  flex-direction: column;
}

.brand-name {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text);
  line-height: 1.2;
  letter-spacing: 0.02em;
}

.brand-tagline {
  font-size: 0.72rem;
  color: var(--muted);
  line-height: 1.2;
}

.desktop-nav {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.desktop-nav a {
  font-size: 0.92rem;
  color: var(--text);
  padding: 0.4rem 0.25rem;
  position: relative;
  font-weight: 500;
}

.desktop-nav a.active {
  color: var(--dark-violet-gray);
  font-weight: 600;
}

.desktop-nav a.active::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 15%;
  width: 70%;
  height: 2px;
  background: var(--violet-gray);
  border-radius: 50% 50% 0 0 / 100% 100% 0 0; /* 短弧线效果 */
}

.header-cta-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.5rem 1.25rem;
  background-color: var(--dark-violet-gray);
  color: #ffffff !important;
  font-size: 0.9rem;
  font-weight: 500;
  border-radius: var(--radius-sm);
  transition: background-color 0.2s ease, transform 0.2s ease;
}

.header-cta-btn:hover {
  background-color: var(--violet-gray);
  color: #ffffff !important;
  transform: translateY(-1px);
}

/* Mobile Header Controls */
.mobile-menu-toggle {
  display: none;
  background: none;
  border: 1px solid var(--border);
  padding: 0.4rem 0.75rem;
  border-radius: var(--radius-sm);
  color: var(--text);
  font-size: 0.9rem;
  cursor: pointer;
}

.mobile-nav-overlay {
  display: none;
  position: fixed;
  top: 72px;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: var(--bg);
  z-index: 99;
  padding: 2rem 1.5rem;
  flex-direction: column;
  gap: 1.25rem;
  overflow-y: auto;
  border-top: 1px solid var(--border);
}

.mobile-nav-overlay.open {
  display: flex;
}

.mobile-nav-overlay a {
  font-size: 1.1rem;
  color: var(--text);
  padding: 0.5rem 0;
  border-bottom: 1px solid var(--border-subtle);
}

/* Global Section Layout & Containers */
section {
  padding: 4.5rem 1.5rem;
  position: relative;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
}

.section-tag {
  display: inline-block;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--violet-gray);
  letter-spacing: 0.05em;
  margin-bottom: 0.5rem;
}

.section-header-wrap {
  margin-bottom: 2.5rem;
  position: relative;
}

.arc-header-boundary {
  position: absolute;
  top: -10px;
  left: -20px;
  width: 140px;
  height: 60px;
  border-top: 1.5px solid var(--violet-gray);
  border-left: 1.5px solid var(--violet-gray);
  border-top-left-radius: 80px;
  opacity: 0.35;
  pointer-events: none;
}

/* 00 Hero Section - 环域Hero */
.hero-section {
  min-height: 680px;
  max-height: 760px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  background-color: var(--bg);
  padding: 3rem 1.5rem;
}

.hero-ring-domain {
  position: relative;
  width: 100%;
  max-width: 1100px;
  height: 580px;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* Hero 开放弧线 Decorative Arcs (aria-hidden) */
.hero-arc {
  position: absolute;
  border-style: solid;
  border-color: transparent;
  border-radius: 50%;
  pointer-events: none;
  transition: opacity 0.3s ease;
}

.hero-arc-1 {
  width: 900px;
  height: 520px;
  top: -40px;
  left: 100px;
  border-top-width: 2px;
  border-top-color: var(--violet-gray);
  border-right-width: 1px;
  border-right-color: var(--violet-gray);
  transform: rotate(-12deg);
  opacity: 0.5;
}

.hero-arc-2 {
  width: 820px;
  height: 480px;
  bottom: -30px;
  right: 80px;
  border-bottom-width: 2px;
  border-bottom-color: var(--sage);
  border-left-width: 1px;
  border-left-color: var(--sage);
  transform: rotate(8deg);
  opacity: 0.55;
}

.hero-arc-3 {
  width: 650px;
  height: 380px;
  top: 100px;
  left: -60px;
  border-left-width: 1.5px;
  border-left-color: var(--copper);
  transform: rotate(-25deg);
  opacity: 0.45;
}

/* Hero Central Content Domain */
.hero-center-domain {
  position: relative;
  z-index: 5;
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 3rem 2.5rem;
  max-width: 620px;
  text-align: center;
  box-shadow: var(--shadow-subtle);
}

.hero-brand-badge {
  display: inline-block;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--violet-gray);
  background-color: var(--light-violet-gray);
  padding: 0.25rem 0.85rem;
  border-radius: 20px;
  margin-bottom: 1rem;
}

.hero-main-title {
  font-size: 2.25rem;
  color: var(--text);
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: 1rem;
}

.hero-h1-seo {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--dark-violet-gray);
  margin-bottom: 1.25rem;
  line-height: 1.5;
}

.hero-description {
  font-size: 0.96rem;
  color: var(--body-text);
  margin-bottom: 2rem;
  text-align: justify;
}

.hero-cta-group {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.85rem;
  flex-wrap: wrap;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  background-color: var(--dark-violet-gray);
  color: #ffffff !important;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 0.95rem;
  transition: all 0.2s ease;
}

.btn-primary:hover {
  background-color: var(--violet-gray);
  transform: translateY(-2px);
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  background-color: var(--warm-gray);
  color: var(--text) !important;
  padding: 0.75rem 1.25rem;
  border-radius: var(--radius-sm);
  font-weight: 500;
  font-size: 0.95rem;
  border: 1px solid var(--border);
  transition: all 0.2s ease;
}

.btn-secondary:hover {
  background-color: var(--surface);
  border-color: var(--violet-gray);
}

.btn-copper {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  background-color: var(--copper);
  color: #ffffff !important;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 0.95rem;
  transition: all 0.2s ease;
}

.btn-copper:hover {
  background-color: var(--dark-copper);
  transform: translateY(-2px);
}

/* Outer Arc Domains (Hero Satellite Floating Knowledge Snippets) */
.hero-arc-snippet {
  position: absolute;
  z-index: 4;
  background-color: rgba(255, 255, 255, 0.92);
  border: 1px solid var(--border);
  padding: 0.85rem 1.25rem;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-subtle);
  max-width: 240px;
}

.hero-arc-snippet h4 {
  font-size: 0.85rem;
  color: var(--violet-gray);
  margin-bottom: 0.35rem;
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.hero-arc-snippet p {
  font-size: 0.78rem;
  color: var(--body-text);
  margin-bottom: 0;
  line-height: 1.4;
}

.snippet-domain-1 { top: 30px; left: 20px; border-left: 3px solid var(--violet-gray); }
.snippet-domain-2 { bottom: 40px; right: 20px; border-right: 3px solid var(--sage); }
.snippet-domain-3 { bottom: 30px; left: 40px; border-left: 3px solid var(--copper); }

/* Section 01: 星维机场是什么？ (认知环) */
.section-basics {
  background-color: var(--surface);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.cognition-ring-layout {
  position: relative;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  align-items: center;
  margin-top: 2rem;
}

.cognition-center-core {
  background-color: var(--light-violet-gray);
  border: 1px solid var(--border);
  padding: 2.5rem;
  border-radius: var(--radius-lg);
  position: relative;
}

.cognition-center-core h3 {
  color: var(--dark-violet-gray);
  font-size: 1.35rem;
  margin-bottom: 1rem;
}

.cognition-domains-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.25rem;
}

.cognition-domain-item {
  background-color: var(--bg);
  border: 1px solid var(--border);
  padding: 1.25rem;
  border-radius: var(--radius-md);
  position: relative;
}

.cognition-domain-item::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 40px;
  height: 40px;
  border-top: 2px solid var(--sage);
  border-left: 2px solid var(--sage);
  border-top-left-radius: 8px;
}

.cognition-domain-item h4 {
  font-size: 1.05rem;
  color: var(--text);
  margin-bottom: 0.5rem;
}

.cognition-domain-item p {
  font-size: 0.88rem;
  margin-bottom: 0;
}

/* Section 02: 第一次选择应该先看什么？ (新手选择逻辑) */
.section-newbie {
  background-color: var(--bg);
}

.newbie-arc-wrapper {
  position: relative;
  border: 1fr;
  padding: 2.5rem;
  background-color: var(--surface);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
}

.newbie-arc-shape {
  position: absolute;
  top: -30px;
  right: -30px;
  width: 320px;
  height: 320px;
  border-radius: 50%;
  border-top: 2px solid var(--copper);
  border-right: 2px solid var(--copper);
  pointer-events: none;
  opacity: 0.4;
}

.newbie-path-steps {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 1rem;
  margin: 2rem 0;
  position: relative;
}

.newbie-step-card {
  flex: 1;
  background-color: var(--bg);
  border: 1px solid var(--border);
  padding: 1.25rem 1rem;
  border-radius: var(--radius-md);
  text-align: center;
}

.step-number {
  display: inline-block;
  width: 28px;
  height: 28px;
  line-height: 28px;
  background-color: var(--dark-violet-gray);
  color: #fff;
  border-radius: 50%;
  font-size: 0.8rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
}

.step-title {
  font-weight: 600;
  color: var(--text);
  font-size: 0.95rem;
  margin-bottom: 0.35rem;
}

.newbie-misconceptions {
  margin-top: 2.5rem;
  background-color: var(--light-sage);
  border-left: 4px solid var(--sage);
  padding: 1.5rem;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
}

.newbie-misconceptions h4 {
  color: var(--dark-sage);
  margin-bottom: 0.75rem;
}

.newbie-misconceptions ul {
  margin-bottom: 0;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.5rem 1.5rem;
}

/* Section 03: 流量、节点、线路 (知识三域) */
.section-three-domains {
  background-color: var(--surface);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.three-domains-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
  margin-top: 2rem;
}

.domain-column {
  background-color: var(--bg);
  border-radius: var(--radius-lg);
  padding: 2rem 1.5rem;
  position: relative;
  border: 1px solid var(--border);
}

.domain-column.traffic {
  border-top: 3px solid var(--violet-gray);
}

.domain-column.node {
  border-top: 3px solid var(--sage);
}

.domain-column.line {
  border-top: 3px solid var(--copper);
}

.domain-column-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.25rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--border-subtle);
}

.domain-column-header h3 {
  font-size: 1.25rem;
  margin-bottom: 0;
}

.domain-badge {
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.2rem 0.6rem;
  border-radius: 4px;
}

.domain-column.traffic .domain-badge { background-color: var(--light-violet-gray); color: var(--violet-gray); }
.domain-column.node .domain-badge { background-color: var(--light-sage); color: var(--sage); }
.domain-column.line .domain-badge { background-color: var(--warm-gray); color: var(--copper); }

/* Section 04: 不同地区节点 (地区环带) */
.section-regions {
  background-color: var(--bg);
}

.region-ring-wrapper {
  position: relative;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  margin-top: 2rem;
}

.region-band-left, .region-band-right {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.region-card {
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1.75rem;
  position: relative;
}

.region-card-header {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 0.75rem;
}

.region-card-header h3 {
  margin-bottom: 0;
  font-size: 1.2rem;
}

.region-tag {
  font-size: 0.75rem;
  color: var(--muted);
  border: 1px solid var(--border-subtle);
  padding: 0.15rem 0.5rem;
  border-radius: 3px;
}

/* Section 05: AI与流媒体 (平台/IP解释区) */
.section-platforms {
  background-color: var(--surface);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.platform-open-domains {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2.5rem;
  margin-top: 2rem;
  position: relative;
}

.platform-domain-box {
  background-color: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2rem;
  position: relative;
}

.platform-domain-box.ai {
  border-top: 3px solid var(--dark-violet-gray);
}

.platform-domain-box.streaming {
  border-top: 3px solid var(--copper);
}

.platform-tags-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 1rem 0 1.5rem 0;
}

.platform-pill {
  background-color: var(--surface);
  border: 1px solid var(--border);
  padding: 0.3rem 0.75rem;
  border-radius: 15px;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text);
}

.platform-qa-snippet {
  background-color: var(--surface);
  border-left: 3px solid var(--violet-gray);
  padding: 1rem 1.25rem;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  margin-top: 1.25rem;
}

.platform-qa-snippet h4 {
  font-size: 0.95rem;
  color: var(--dark-violet-gray);
  margin-bottom: 0.4rem;
}

.platform-qa-snippet p {
  font-size: 0.88rem;
  margin-bottom: 0;
}

/* Section 06: 客户端使用 (设备环域目录) */
.section-clients {
  background-color: var(--bg);
}

.client-ring-directory {
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: 2rem;
  margin-top: 2rem;
  align-items: start;
}

.client-core-intro {
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2rem;
}

.client-os-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.25rem;
}

.client-os-box {
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1.5rem;
}

.client-os-box h4 {
  font-size: 1.1rem;
  color: var(--dark-violet-gray);
  margin-bottom: 0.75rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.client-os-box ul {
  font-size: 0.88rem;
  padding-left: 1.25rem;
  margin-bottom: 0;
}

/* Section 07: 连接排障 (问题环) */
.section-trouble {
  background-color: var(--surface);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.trouble-ring-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
  margin-top: 2rem;
}

.trouble-item-card {
  background-color: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  position: relative;
}

.trouble-item-card h4 {
  font-size: 1.05rem;
  color: var(--text);
  margin-bottom: 0.75rem;
}

.trouble-item-card p {
  font-size: 0.9rem;
  margin-bottom: 0;
}

/* Section 08: 知识型完整评测 (评测区) */
.section-review {
  background-color: var(--bg);
}

.review-banner-domain {
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 3rem 2.5rem;
  position: relative;
}

.review-banner-domain::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--dark-violet-gray), var(--sage), var(--copper));
  border-radius: 10px 10px 0 0;
}

.review-summary-box {
  background-color: var(--light-violet-gray);
  padding: 1.5rem;
  border-radius: var(--radius-md);
  margin: 1.5rem 0 2rem 0;
}

.review-summary-box h4 {
  color: var(--dark-violet-gray);
  margin-bottom: 0.5rem;
}

.review-topics-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
  margin-bottom: 2rem;
}

.review-topic-tag {
  background-color: var(--bg);
  border: 1px solid var(--border);
  padding: 1rem;
  border-radius: var(--radius-md);
  font-size: 0.9rem;
}

.review-topic-tag strong {
  display: block;
  color: var(--text);
  margin-bottom: 0.25rem;
}

/* Section 09: 完整套餐价格 (环域价目 - AFTER REVIEW) */
.section-pricing {
  background-color: var(--surface);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.pricing-disclaimer-note {
  font-size: 0.82rem;
  color: var(--muted);
  background-color: var(--bg);
  border: 1px solid var(--border-subtle);
  padding: 0.6rem 1rem;
  border-radius: var(--radius-sm);
  margin-bottom: 2rem;
  text-align: center;
}

.pricing-ring-layout {
  display: grid;
  grid-template-columns: 1fr 1.3fr 1fr;
  gap: 1.5rem;
  align-items: center;
  margin-top: 2rem;
}

.pricing-column-side {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

/* Central Featured Plan */
.pricing-card-featured {
  background-color: var(--light-violet-gray);
  border: 2px solid var(--dark-violet-gray);
  border-radius: var(--radius-lg);
  padding: 2.5rem 2rem;
  position: relative;
  text-align: center;
  box-shadow: var(--shadow-subtle);
}

.featured-badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background-color: var(--copper);
  color: #fff;
  font-size: 0.78rem;
  font-weight: 700;
  padding: 0.25rem 1rem;
  border-radius: 20px;
}

.plan-code {
  font-size: 0.8rem;
  color: var(--muted);
  font-weight: 700;
}

.plan-name {
  font-size: 1.4rem;
  color: var(--text);
  font-weight: 700;
  margin: 0.25rem 0 0.75rem 0;
}

.plan-traffic {
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--dark-violet-gray);
  margin-bottom: 0.5rem;
}

.plan-price {
  font-size: 2.2rem;
  font-weight: 800;
  color: var(--text);
  margin-bottom: 1.25rem;
}

.plan-price span {
  font-size: 0.9rem;
  font-weight: 400;
  color: var(--body-text);
}

.plan-features-list {
  text-align: left;
  list-style: none;
  padding: 0;
  margin: 1.5rem 0;
  font-size: 0.9rem;
}

.plan-features-list li {
  padding: 0.4rem 0;
  border-bottom: 1px solid rgba(0,0,0,0.05);
}

/* Outer Auxiliary Plans */
.pricing-card-aux {
  background-color: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  position: relative;
}

.pricing-card-aux.light-sage-bg { background-color: var(--light-sage); }
.pricing-card-aux.warm-gray-bg { background-color: var(--warm-gray); }

.pricing-card-aux .plan-name { font-size: 1.15rem; }
.pricing-card-aux .plan-traffic { font-size: 1.25rem; margin-bottom: 0.25rem; }
.pricing-card-aux .plan-price { font-size: 1.5rem; margin-bottom: 0.75rem; }

/* Section 10: 知识教程中心 */
.section-tutorials {
  background-color: var(--bg);
}

.tutorials-domain-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  margin-top: 2rem;
}

.tutorial-domain-category {
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2rem;
}

.tutorial-domain-category h3 {
  font-size: 1.25rem;
  color: var(--dark-violet-gray);
  border-bottom: 2px solid var(--light-violet-gray);
  padding-bottom: 0.75rem;
  margin-bottom: 1.25rem;
}

.tutorial-articles-list {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.tutorial-article-item {
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border-subtle);
}

.tutorial-article-item:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.tutorial-article-item h4 {
  font-size: 1rem;
  margin-bottom: 0.35rem;
}

.tutorial-article-item p {
  font-size: 0.85rem;
  color: var(--body-text);
  margin-bottom: 0.35rem;
}

.article-meta-row {
  display: flex;
  gap: 1rem;
  font-size: 0.78rem;
  color: var(--muted);
}

/* Section 11: 常见问题 (FAQ) */
.section-faq {
  background-color: var(--surface);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.faq-domain-container {
  max-width: 900px;
  margin: 2rem auto 0 auto;
}

.faq-group-title {
  font-size: 1.15rem;
  color: var(--violet-gray);
  margin: 2rem 0 1rem 0;
  padding-bottom: 0.35rem;
  border-bottom: 1px solid var(--border);
}

.faq-group-title:first-child {
  margin-top: 0;
}

.faq-item {
  border-bottom: 1px solid var(--border-subtle);
}

.faq-button {
  width: 100%;
  text-align: left;
  background: none;
  border: none;
  padding: 1.15rem 0;
  font-size: 1.02rem;
  font-weight: 600;
  color: var(--text);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;

  font-family: inherit;
}

.faq-button:hover {
  color: var(--dark-violet-gray);
}

.faq-icon {
  font-size: 1.2rem;
  color: var(--violet-gray);
  transition: transform 0.25 ease;
  flex-shrink: 0;
}

.faq-button[aria-expanded="true"] .faq-icon {
  transform: rotate(45deg);
}

.faq-panel {
  display: none;
  padding-bottom: 1.25rem;
  font-size: 0.94rem;
  color: var(--body-text);
  line-height: 1.8;
}

.faq-panel.open {
  display: block;
}

/* Footer Section - 深紫灰知识目录型 */
.site-footer {
  background-color: var(--dark-violet-gray);
  color: #F7F5F6;
  padding: 3.5rem 1.5rem 2rem 1.5rem;
  font-size: 0.88rem;
  border-top: 1px solid var(--border);
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.8fr 1fr 1fr 1fr 1fr;
  gap: 2.5rem;
  padding-bottom: 2.5rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.12);
}

.footer-col-brand h3 {
  color: #FFFFFF;
  font-size: 1.25rem;
  margin-bottom: 0.5rem;
}

.footer-col-brand p {
  color: #CCC8D4;
  font-size: 0.85rem;
  line-height: 1.6;
}

.footer-col h4 {
  color: var(--sage); /* 鼠尾草绿小标题 */
  font-size: 0.92rem;
  font-weight: 600;
  margin-bottom: 1.25rem;
  letter-spacing: 0.04em;
}

.footer-col ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.footer-col li {
  margin-bottom: 0.65rem;
}

.footer-col a {
  color: #CCC8D4;
  transition: color 0.2s ease;
}

.footer-col a:hover {
  color: #FFFFFF;
}

.footer-bottom {
  max-width: var(--max-width);
  margin: 1.75rem auto 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  color: #CCC8D4;
  font-size: 0.82rem;
}

.footer-friends-links {
  display: flex;
  gap: 1.25rem;
}

.footer-friends-links a {
  color: #CCC8D4;
}

.footer-friends-links a:hover {
  color: #FFFFFF;
}

/* Common Page Templates Layout (Articles, Categories, Static Pages) */
.page-header-banner {
  background-color: var(--bg);
  border-bottom: 1px solid var(--border);
  padding: 3rem 1.5rem;
  position: relative;
}

.breadcrumb {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.85rem;
  color: var(--muted);
  margin-bottom: 1rem;
}

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

.article-container {
  max-width: var(--article-max-width);
  margin: 0 auto;
  padding: 3rem 1.5rem;
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  margin-top: 2rem;
  margin-bottom: 4rem;
}

.quick-conclusion-box {
  background-color: var(--light-sage);
  border-left: 4px solid var(--sage);
  padding: 1.25rem 1.5rem;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  margin: 1.5rem 0 2rem 0;
}

.quick-conclusion-box h4 {
  color: var(--dark-sage);
  font-size: 1.05rem;
  margin-bottom: 0.5rem;
}

.article-body {
  font-size: 1.05rem;
  line-height: 1.85;
  color: var(--text);
}

.article-body h2 {
  margin-top: 2.25rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border-subtle);
}

.article-body h3 {
  margin-top: 1.75rem;
}

.article-related-box {
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border);
}

.article-related-box h4 {
  margin-bottom: 1rem;
  color: var(--dark-violet-gray);
}

.category-articles-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
  margin-top: 2rem;
}

.category-article-card {
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1.75rem;
}

/* Media Queries for Responsive Design */
@media (max-width: 1024px) {
  .hero-ring-domain { height: auto; }
  .hero-arc-snippet { display: none; }
  .cognition-ring-layout { grid-template-columns: 1fr; }
  .three-domains-grid { grid-template-columns: 1fr; }
  .region-ring-wrapper { grid-template-columns: 1fr; }
  .platform-open-domains { grid-template-columns: 1fr; }
  .client-ring-directory { grid-template-columns: 1fr; }
  .trouble-ring-grid { grid-template-columns: 1fr 1fr; }
  .pricing-ring-layout { grid-template-columns: 1fr; }
  .tutorials-domain-grid { grid-template-columns: 1fr; }
  .footer-inner { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 768px) {
  .desktop-nav { display: none; }
  .mobile-menu-toggle { display: block; }
  .hero-section { min-height: auto; max-height: none; padding: 2.5rem 1rem; }
  .hero-arc-1, .hero-arc-2, .hero-arc-3 { display: none; }
  .hero-center-domain { padding: 1.75rem 1.25rem; }
  .newbie-path-steps { flex-direction: column; }
  .cognition-domains-grid { grid-template-columns: 1fr; }
  .newbie-misconceptions ul { grid-template-columns: 1fr; }
  .client-os-grid { grid-template-columns: 1fr; }
  .trouble-ring-grid { grid-template-columns: 1fr; }
  .review-topics-grid { grid-template-columns: 1fr; }
  .footer-inner { grid-template-columns: 1fr; gap: 2rem; }
  .footer-bottom { flex-direction: column; text-align: center; }
}

@media (max-width: 430px) {
  html { font-size: 15px; }
  section { padding: 3rem 1rem; }
  .hero-main-title { font-size: 1.85rem; }
  .hero-cta-group { flex-direction: column; width: 100%; }
  .btn-primary, .btn-secondary, .btn-copper { width: 100%; justify-content: center; }
}

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