/* ==================================================
   赔钱机场 - 视觉设计样式表
   主题：预算拆解台 (The Budget Deconstruction Station)
   风格：纯白商务 · 石墨黑 · 克制砖红 · 灰绿辅助 · 编辑式排版
   ================================================== */

:root {
  /* 配色系统 */
  --bg-main: #F8F8F6;
  --bg-white: #FFFFFF;
  --bg-sub: #F2F3F0;
  --bg-card: #FFFFFF;
  --bg-footer: #EEEFEA;
  
  --text-main: #1E2224;
  --text-body: #5A6165;
  --text-muted: #7E878B;
  --text-footer: #474F52;
  
  --accent-red: #A34F42;
  --accent-red-deep: #803E35;
  --accent-green: #436D68;
  --accent-red-light: #F5ECE9;
  --accent-green-light: #EDF3F1;
  
  --border-color: #E2E3DE;
  --border-light: #ECEEE9;
  
  /* 字体系统 */
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
  --font-mono: SFMono-Regular, Consolas, "Liberation Mono", Menlo, monospace;
  
  /* 阴影与圆角（极其克制） */
  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;
  --shadow-subtle: 0 1px 3px rgba(30, 34, 36, 0.04);
  --shadow-hover: 0 4px 12px rgba(30, 34, 36, 0.06);
  
  /* 容器宽度 */
  --container-max: 1180px;
  --article-max: 800px;
  --header-height: 70px;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-main);
  color: var(--text-body);
  line-height: 1.8;
  font-size: 1rem;
  letter-spacing: -0.01em;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* 链接与排版基础 */
a {
  color: inherit;
  text-decoration: none;
  transition: color 0.15s ease, border-color 0.15s ease;
}

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

img, svg {
  vertical-align: middle;
  display: inline-block;
}

h1, h2, h3, h4, h5, h6 {
  color: var(--text-main);
  font-weight: 700;
  line-height: 1.35;
  letter-spacing: -0.02em;
}

h1 {
  font-size: clamp(2rem, 4vw, 3rem); /* 32px ~ 48px */
  margin-bottom: 1.25rem;
}

h2 {
  font-size: clamp(1.5rem, 2.8vw, 2.125rem); /* 24px ~ 34px */
  margin-bottom: 1rem;
}

h3 {
  font-size: clamp(1.15rem, 2vw, 1.4rem); /* 18px ~ 22px */
  margin-bottom: 0.75rem;
}

p {
  margin-bottom: 1.25rem;
}

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

li {
  margin-bottom: 0.5rem;
}

/* 布局容器 */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: 1.5rem;
  padding-right: 1.5rem;
}

.article-container {
  max-width: var(--article-max);
}

/* 按钮规范 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.65rem 1.35rem;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all 0.2s ease;
  white-space: nowrap;
  border: 1px solid transparent;
  text-decoration: none;
}

.btn-primary {
  background-color: var(--accent-red);
  color: #FFFFFF;
  border-color: var(--accent-red);
}

.btn-primary:hover {
  background-color: var(--accent-red-deep);
  border-color: var(--accent-red-deep);
  color: #FFFFFF;
}

.btn-primary:hover .btn-arrow {
  transform: translateX(3px);
}

.btn-secondary {
  background-color: var(--bg-white);
  color: var(--text-main);
  border-color: var(--border-color);
}

.btn-secondary:hover {
  border-color: var(--accent-red);
  color: var(--accent-red);
}

.btn-secondary:hover .btn-arrow {
  transform: translateX(3px);
}

.btn-subtle {
  background-color: transparent;
  color: var(--text-main);
  border-color: transparent;
  padding: 0.5rem 0.75rem;
}

.btn-subtle:hover {
  color: var(--accent-red);
}

.btn-arrow {
  transition: transform 0.2s ease;
  font-family: var(--font-sans);
}

/* 标签样式 */
.badge {
  display: inline-flex;
  align-items: center;
  padding: 0.2rem 0.55rem;
  font-size: 0.75rem;
  font-weight: 600;
  border-radius: 2px;
  line-height: 1.2;
}

.badge-red {
  background-color: var(--accent-red-light);
  color: var(--accent-red-deep);
  border: 1px solid rgba(163, 79, 66, 0.2);
}

.badge-green {
  background-color: var(--accent-green-light);
  color: var(--accent-green);
  border: 1px solid rgba(67, 109, 104, 0.25);
}

.badge-gray {
  background-color: var(--bg-sub);
  color: var(--text-body);
  border: 1px solid var(--border-color);
}

/* ==================================================
   Header 导航栏
   ================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--bg-white);
  border-bottom: 1px solid var(--border-color);
  height: var(--header-height);
  transition: background-color 0.2s ease;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.brand-group {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
}

.brand-logo-svg {
  display: block;
}

.brand-text {
  display: flex;
  flex-direction: column;
}

.brand-name {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-main);
  line-height: 1.15;
  letter-spacing: -0.02em;
}

.brand-tagline {
  font-size: 0.75rem;
  color: var(--text-muted);
  line-height: 1.2;
  margin-top: 2px;
}

/* 桌面导航 */
.nav-desktop {
  display: flex;
  align-items: center;
  gap: 1.25rem;
}

.nav-link {
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--text-body);
  padding: 0.4rem 0;
  position: relative;
  transition: color 0.15s ease;
}

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

.nav-link.active {
  color: var(--text-main);
  font-weight: 600;
}

.nav-link.active::after {
  content: "";
  position: absolute;
  bottom: -4px;
  left: 0;
  right: 0;
  height: 2px;
  background-color: var(--accent-red);
}

.header-cta-group {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

/* 移动端菜单按钮与抽屉 */
.mobile-menu-btn {
  display: none;
  background: transparent;
  border: 1px solid var(--border-color);
  padding: 0.45rem 0.75rem;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-main);
  border-radius: var(--radius-sm);
  cursor: pointer;
}

.mobile-nav-drawer {
  display: none;
  position: fixed;
  top: var(--header-height);
  left: 0;
  right: 0;
  bottom: 0;
  background-color: var(--bg-white);
  border-top: 1px solid var(--border-color);
  padding: 1.5rem;
  overflow-y: auto;
  z-index: 99;
}

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

.mobile-nav-list {
  list-style: none;
  padding: 0;
  margin: 0 0 1.5rem 0;
}

.mobile-nav-item {
  border-bottom: 1px solid var(--border-light);
  margin-bottom: 0;
}

.mobile-nav-link {
  display: block;
  padding: 0.85rem 0;
  font-size: 1.05rem;
  font-weight: 500;
  color: var(--text-main);
}

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

.mobile-nav-cta {
  width: 100%;
}

/* ==================================================
   Hero 预算决策台
   ================================================== */
.hero-section {
  background-color: var(--bg-white);
  border-bottom: 1px solid var(--border-color);
  padding: 3rem 0 3.5rem 0;
}

.hero-header {
  margin-bottom: 2rem;
}

.hero-label-bar {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  margin-bottom: 0.85rem;
}

.hero-badge {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--accent-red-deep);
  background-color: var(--accent-red-light);
  padding: 0.2rem 0.6rem;
  border-radius: 2px;
}

.hero-brand-tag {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
}

.hero-slogan {
  font-size: clamp(2rem, 3.8vw, 2.75rem);
  font-weight: 800;
  color: var(--text-main);
  line-height: 1.25;
  margin-bottom: 0.5rem;
  letter-spacing: -0.025em;
}

.hero-subslogan {
  font-size: 1.1rem;
  font-weight: 500;
  color: var(--accent-green);
  margin-bottom: 1rem;
}

.hero-h1 {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-body);
  margin-bottom: 1rem;
  line-height: 1.5;
}

.hero-desc {
  max-width: 820px;
  font-size: 1rem;
  color: var(--text-body);
  line-height: 1.8;
  margin-bottom: 1.5rem;
}

.hero-cta-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem;
  align-items: center;
  margin-bottom: 2.5rem;
}

/* 你的预算是多少？横向预算拆解条 */
.budget-decision-board {
  background-color: var(--bg-main);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
}

.board-title-row {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: 1rem;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 0.75rem;
}

.board-title {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-main);
}

.board-hint {
  font-size: 0.82rem;
  color: var(--text-muted);
}

.budget-strip-list {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.budget-strip-item {
  display: grid;
  grid-template-columns: 140px 1fr 160px;
  align-items: center;
  background-color: var(--bg-white);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  padding: 0.85rem 1.25rem;
  text-decoration: none;
  transition: all 0.15s ease;
}

.budget-strip-item:hover {
  border-color: var(--accent-red);
  box-shadow: var(--shadow-subtle);
  transform: translateX(2px);
}

.strip-budget {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--accent-red-deep);
  font-family: var(--font-sans);
}

.strip-scene {
  font-size: 0.92rem;
  color: var(--text-body);
}

.strip-action {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-main);
  text-align: right;
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 0.35rem;
}

.budget-strip-item:hover .strip-action {
  color: var(--accent-red);
}

.board-disclaimer {
  margin-top: 1rem;
  font-size: 0.82rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 0;
}

/* ==================================================
   模块通用规范
   ================================================== */
.page-section {
  padding: 4.5rem 0;
  border-bottom: 1px solid var(--border-color);
}

.page-section:nth-child(even) {
  background-color: var(--bg-sub);
}

.page-section:nth-child(odd) {
  background-color: var(--bg-main);
}

.section-label {
  display: inline-block;
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  color: var(--accent-red);
  margin-bottom: 0.5rem;
}

.section-header {
  margin-bottom: 2.25rem;
  max-width: 860px;
}

.section-intro {
  font-size: 1.05rem;
  color: var(--text-body);
  line-height: 1.8;
  margin-top: 0.5rem;
}

/* ==================================================
   01 / 预算选择 四列表格/清单
   ================================================== */
.budget-selection-table-wrapper {
  overflow-x: auto;
  background-color: var(--bg-white);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 0.95rem;
}

.data-table th {
  background-color: var(--bg-sub);
  color: var(--text-main);
  font-weight: 700;
  padding: 0.95rem 1.25rem;
  border-bottom: 1px solid var(--border-color);
  white-space: nowrap;
}

.data-table td {
  padding: 1.1rem 1.25rem;
  border-bottom: 1px solid var(--border-light);
  color: var(--text-body);
  vertical-align: top;
}

.data-table tr:last-child td {
  border-bottom: none;
}

.data-table tr:hover td {
  background-color: #FAFAFA;
}

.table-budget-val {
  font-weight: 700;
  color: var(--text-main);
  font-size: 1.05rem;
}

/* ==================================================
   02 / 流量需求 流量刻度
   ================================================== */
.traffic-scale-container {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.25rem;
}

.traffic-scale-node {
  background-color: var(--bg-white);
  border: 1px solid var(--border-color);
  border-top: 3px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 1.5rem;
  position: relative;
  transition: all 0.2s ease;
}

.traffic-scale-node:hover {
  border-top-color: var(--accent-red);
  transform: translateY(-2px);
  box-shadow: var(--shadow-hover);
}

.traffic-node-value {
  font-size: 1.75rem;
  font-weight: 800;
  color: var(--text-main);
  line-height: 1.1;
  margin-bottom: 0.25rem;
  letter-spacing: -0.03em;
}

.traffic-node-unit {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
  margin-bottom: 1rem;
}

.traffic-node-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--accent-green);
  margin-bottom: 0.75rem;
}

.traffic-node-desc {
  font-size: 0.9rem;
  color: var(--text-body);
  line-height: 1.7;
  margin-bottom: 0;
}

/* ==================================================
   03 / 使用场景 需求清单
   ================================================== */
.scenario-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.scenario-item {
  display: grid;
  grid-template-columns: 60px 180px 1fr 240px;
  align-items: center;
  background-color: var(--bg-white);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 1.25rem 1.5rem;
  transition: border-color 0.2s ease;
}

.scenario-item:hover {
  border-color: var(--accent-red);
}

.scenario-num {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

.scenario-name {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-main);
}

.scenario-desc {
  font-size: 0.92rem;
  color: var(--text-body);
  padding-right: 1.5rem;
}

.scenario-focus {
  font-size: 0.88rem;
  background-color: var(--bg-sub);
  padding: 0.5rem 0.85rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-light);
  color: var(--text-main);
}

/* ==================================================
   04 / 地区节点 地区预算索引
   ================================================== */
.node-index-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.node-index-row {
  display: grid;
  grid-template-columns: 140px 1fr 1fr;
  align-items: center;
  background-color: var(--bg-white);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 1.25rem 1.5rem;
}

.node-region-name {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-main);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.node-usage {
  font-size: 0.92rem;
  color: var(--text-body);
}

.node-attention {
  font-size: 0.88rem;
  color: var(--accent-red-deep);
  background-color: var(--accent-red-light);
  padding: 0.5rem 0.85rem;
  border-radius: var(--radius-sm);
}

/* ==================================================
   05 / 线路知识 线路成本理解表
   ================================================== */
.line-table-note {
  margin-top: 1rem;
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* ==================================================
   06 / 客户端 设备使用清单
   ================================================== */
.device-checklist {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.25rem;
}

.device-item {
  background-color: var(--bg-white);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.device-item-top {
  margin-bottom: 1rem;
}

.device-item-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 0.5rem;
}

.device-platform {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text-main);
}

.device-type-tag {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent-green);
  background-color: var(--accent-green-light);
  padding: 0.15rem 0.5rem;
  border-radius: 2px;
}

.device-desc {
  font-size: 0.92rem;
  color: var(--text-body);
  line-height: 1.7;
}

.device-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  border-top: 1px solid var(--border-light);
  padding-top: 0.85rem;
}

.device-link-btn {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--accent-red);
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
}

.device-link-btn:hover {
  color: var(--accent-red-deep);
  text-decoration: underline;
}

/* ==================================================
   07 / 完整套餐 预算档位表
   ================================================== */
.plan-deck-container {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.plan-row-item {
  display: grid;
  grid-template-columns: 160px 140px 1fr 130px 150px;
  align-items: center;
  background-color: var(--bg-white);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 1.25rem 1.5rem;
  transition: all 0.15s ease;
  position: relative;
}

.plan-row-item:hover {
  border-color: var(--border-color);
  box-shadow: var(--shadow-subtle);
}

/* 主力预算 唯一主推 */
.plan-row-featured {
  background-color: var(--accent-red-light);
  border: 1px solid rgba(163, 79, 66, 0.3);
  border-left: 4px solid var(--accent-red);
}

.plan-price-group {
  display: flex;
  align-items: baseline;
  gap: 0.25rem;
}

.plan-price-currency {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-main);
}

.plan-price-number {
  font-size: 1.85rem;
  font-weight: 800;
  color: var(--text-main);
  line-height: 1;
  letter-spacing: -0.03em;
}

.plan-row-featured .plan-price-number {
  color: var(--accent-red-deep);
}

.plan-price-cycle {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.plan-traffic-val {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--accent-green);
}

.plan-scene-desc {
  font-size: 0.92rem;
  color: var(--text-body);
  padding-right: 1rem;
}

.plan-name-label {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.plan-tier-name {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-main);
}

.plan-cta-cell {
  text-align: right;
}

/* ==================================================
   08 / 赔钱机场深度评测 介绍区
   ================================================== */
.review-highlight-card {
  background-color: var(--bg-white);
  border: 1px solid var(--border-color);
  border-left: 4px solid var(--accent-red);
  border-radius: var(--radius-sm);
  padding: 2rem;
}

.review-highlight-title {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 1rem;
}

.review-highlight-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
  margin: 1.5rem 0;
}

.review-highlight-item {
  border-top: 1px solid var(--border-light);
  padding-top: 0.75rem;
}

.review-item-label {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text-muted);
  margin-bottom: 0.25rem;
}

.review-item-text {
  font-size: 0.95rem;
  color: var(--text-main);
  font-weight: 600;
}

/* ==================================================
   09 / 使用教程 预算知识清单
   ================================================== */
.knowledge-list {
  display: flex;
  flex-direction: column;
}

.knowledge-row {
  display: grid;
  grid-template-columns: 80px 1fr 140px;
  align-items: center;
  padding: 1.35rem 0;
  border-bottom: 1px solid var(--border-color);
  transition: background-color 0.15s ease;
}

.knowledge-row:first-child {
  border-top: 1px solid var(--border-color);
}

.knowledge-row:hover {
  background-color: rgba(255, 255, 255, 0.5);
}

.knowledge-num {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

.knowledge-content {
  padding-right: 1.5rem;
}

.knowledge-meta-bar {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 0.35rem;
}

.knowledge-category {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent-red);
}

.knowledge-title {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 0.35rem;
}

.knowledge-title a:hover {
  color: var(--accent-red);
}

.knowledge-summary {
  font-size: 0.9rem;
  color: var(--text-body);
  margin-bottom: 0;
  line-height: 1.6;
}

.knowledge-action {
  text-align: right;
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 0.25rem;
}

.knowledge-read-time {
  font-size: 0.78rem;
  color: var(--text-muted);
}

.knowledge-link {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--accent-red);
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
}

.knowledge-link:hover {
  color: var(--accent-red-deep);
}

/* ==================================================
   10 / 网络排障 问题成本清单
   ================================================== */
.troubleshooting-table {
  background-color: var(--bg-white);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow-x: auto;
}

/* ==================================================
   11 / 常见问题 预算问答 (Accordion)
   ================================================== */
.faq-accordion-group {
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

.faq-item {
  background-color: var(--bg-white);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  overflow: hidden;
  transition: border-color 0.15s ease;
}

.faq-item:hover {
  border-color: #C8CBC4;
}

.faq-summary {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1.1rem 1.25rem;
  cursor: pointer;
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-main);
  list-style: none;
  user-select: none;
}

.faq-summary::-webkit-details-marker {
  display: none;
}

.faq-icon {
  font-size: 1.25rem;
  font-weight: 400;
  color: var(--text-muted);
  transition: transform 0.2s ease;
}

details[open] .faq-icon {
  transform: rotate(45deg);
}

.faq-content {
  padding: 0 1.25rem 1.25rem 1.25rem;
  font-size: 0.95rem;
  color: var(--text-body);
  line-height: 1.8;
  border-top: 1px solid var(--border-light);
  margin-top: -0.25rem;
  padding-top: 1rem;
}

/* ==================================================
   Footer 页脚设计
   ================================================== */
.site-footer {
  background-color: var(--bg-footer);
  color: var(--text-footer);
  border-top: 1px solid var(--border-color);
  padding: 3.5rem 0 1.5rem 0;
  font-size: 0.9rem;
}

.footer-top-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr 1fr;
  gap: 2rem;
  margin-bottom: 2.5rem;
  padding-bottom: 2.5rem;
  border-bottom: 1px solid var(--border-color);
}

.footer-brand-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 0.5rem;
}

.footer-brand-tagline {
  font-size: 0.85rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 1.25rem;
}

.footer-col-title {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 0.85rem;
}

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

.footer-nav-list li {
  margin-bottom: 0.5rem;
}

.footer-nav-list a {
  color: var(--text-footer);
  font-size: 0.88rem;
}

.footer-nav-list a:hover {
  color: var(--accent-red);
}

.footer-bottom-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.82rem;
  color: var(--text-muted);
}

.footer-friend-links {
  display: flex;
  align-items: center;
  gap: 1.25rem;
}

.footer-friend-links a {
  color: var(--text-muted);
  text-decoration: underline;
  text-underline-offset: 3px;
}

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

/* ==================================================
   文章详情页排版规范
   ================================================== */
.article-header {
  padding: 3rem 0 2rem 0;
  border-bottom: 1px solid var(--border-color);
  background-color: var(--bg-white);
  margin-bottom: 2.5rem;
}

.breadcrumb-nav {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 1.25rem;
  display: flex;
  align-items: center;
  gap: 0.4rem;
  flex-wrap: wrap;
}

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

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

.article-category-badge {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--accent-red);
  background-color: var(--accent-red-light);
  padding: 0.2rem 0.5rem;
  border-radius: 2px;
  margin-bottom: 0.75rem;
}

.article-title {
  font-size: clamp(1.85rem, 3.5vw, 2.5rem);
  font-weight: 800;
  color: var(--text-main);
  line-height: 1.3;
  margin-bottom: 1rem;
}

.article-summary-lead {
  font-size: 1.1rem;
  color: var(--text-body);
  line-height: 1.8;
  margin-bottom: 1.5rem;
  font-weight: 400;
}

.article-meta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  font-size: 0.85rem;
  color: var(--text-muted);
  border-top: 1px solid var(--border-light);
  padding-top: 1rem;
}

/* GEO 快速结论框 */
.quick-conclusion-box {
  background-color: var(--bg-sub);
  border: 1px solid var(--border-color);
  border-left: 4px solid var(--accent-green);
  border-radius: var(--radius-sm);
  padding: 1.25rem 1.5rem;
  margin-bottom: 2rem;
}

.quick-conclusion-title {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--accent-green);
  margin-bottom: 0.5rem;
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.quick-conclusion-text {
  font-size: 0.95rem;
  color: var(--text-main);
  line-height: 1.75;
  margin-bottom: 0;
}

/* 本文目录 */
.article-toc {
  background-color: var(--bg-white);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 1.25rem 1.5rem;
  margin-bottom: 2.5rem;
}

.toc-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 0.75rem;
}

.toc-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.toc-list li {
  margin-bottom: 0.35rem;
  font-size: 0.92rem;
}

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

.toc-list a:hover {
  color: var(--accent-red);
}

/* 正文区域 */
.article-content {
  background-color: var(--bg-white);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 2.5rem;
  margin-bottom: 2.5rem;
}

.article-content h2 {
  font-size: 1.5rem;
  margin-top: 2.25rem;
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border-light);
}

.article-content h2:first-child {
  margin-top: 0;
}

.article-content h3 {
  font-size: 1.2rem;
  margin-top: 1.75rem;
  margin-bottom: 0.75rem;
}

.article-content p {
  font-size: 1rem;
  color: var(--text-body);
  line-height: 1.85;
  margin-bottom: 1.25rem;
}

/* 文章商业卡片 */
.article-cta-box {
  background-color: var(--accent-red-light);
  border: 1px solid rgba(163, 79, 66, 0.25);
  border-radius: var(--radius-sm);
  padding: 1.75rem;
  text-align: center;
  margin: 2.5rem 0;
}

.article-cta-box h3 {
  font-size: 1.25rem;
  color: var(--text-main);
  margin-bottom: 0.5rem;
}

.article-cta-box p {
  font-size: 0.95rem;
  color: var(--text-body);
  margin-bottom: 1.25rem;
}

/* 相关阅读 & 上下篇 */
.article-relations {
  background-color: var(--bg-white);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 1.5rem;
  margin-bottom: 2rem;
}

.relations-title {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 1rem;
  border-bottom: 1px solid var(--border-light);
  padding-bottom: 0.5rem;
}

.prev-next-bar {
  display: flex;
  justify-content: space-between;
  gap: 1.5rem;
  margin-top: 1.5rem;
  border-top: 1px solid var(--border-light);
  padding-top: 1rem;
}

.prev-link, .next-link {
  font-size: 0.9rem;
  color: var(--text-main);
}

.prev-link span, .next-link span {
  display: block;
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* 分类页样式 */
.category-header {
  background-color: var(--bg-white);
  border-bottom: 1px solid var(--border-color);
  padding: 3rem 0 2.5rem 0;
  margin-bottom: 2.5rem;
}

/* ==================================================
   响应式断点测试 (1440, 1024, 768, 430, 390, 375)
   ================================================== */
@media (max-width: 1024px) {
  .nav-desktop {
    display: none;
  }
  
  .mobile-menu-btn {
    display: block;
  }
  
  .traffic-scale-container {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .scenario-item {
    grid-template-columns: 50px 140px 1fr;
    gap: 0.75rem;
  }
  
  .scenario-focus {
    grid-column: 1 / -1;
  }
  
  .node-index-row {
    grid-template-columns: 120px 1fr;
    gap: 0.75rem;
  }
  
  .node-attention {
    grid-column: 1 / -1;
  }
  
  .plan-row-item {
    grid-template-columns: 130px 120px 1fr 130px;
    gap: 0.75rem;
  }
  
  .plan-cta-cell {
    grid-column: 1 / -1;
    text-align: left;
    margin-top: 0.5rem;
  }
  
  .footer-top-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  :root {
    --header-height: 62px;
  }
  
  .page-section {
    padding: 3rem 0;
  }
  
  .traffic-scale-container {
    grid-template-columns: 1fr;
  }
  
  .device-checklist {
    grid-template-columns: 1fr;
  }
  
  .review-highlight-grid {
    grid-template-columns: 1fr;
  }
  
  .budget-strip-item {
    grid-template-columns: 1fr;
    gap: 0.35rem;
    padding: 0.85rem 1rem;
  }
  
  .strip-action {
    justify-content: flex-start;
  }
  
  .knowledge-row {
    grid-template-columns: 1fr;
    gap: 0.5rem;
    padding: 1.25rem 0;
  }
  
  .knowledge-num {
    display: none;
  }
  
  .knowledge-action {
    align-items: flex-start;
    flex-direction: row;
    justify-content: space-between;
    width: 100%;
    margin-top: 0.5rem;
  }
  
  /* 移动端套餐卡片式行排列 */
  .plan-deck-container {
    gap: 1rem;
  }
  
  .plan-row-item {
    grid-template-columns: 1fr;
    gap: 0.6rem;
    padding: 1.25rem 1rem;
  }
  
  .plan-cta-cell {
    margin-top: 0.5rem;
  }
  
  .plan-cta-cell .btn {
    width: 100%;
  }
  
  .footer-top-grid {
    grid-template-columns: 1fr;
    gap: 1.75rem;
  }
  
  .footer-bottom-bar {
    flex-direction: column;
    align-items: flex-start;
    gap: 1rem;
  }
  
  .article-content {
    padding: 1.5rem 1rem;
  }
}

@media (max-width: 430px) {
  /* 针对 430 / 390 / 375 移动端精确优化 */
  .container {
    padding-left: 1rem;
    padding-right: 1rem;
  }
  
  .hero-slogan {
    font-size: 1.75rem;
  }
  
  .hero-cta-bar .btn {
    width: 100%;
  }
  
  .footer-friend-links {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.5rem;
  }
}

/* ==================================================
   prefers-reduced-motion 支持
   ================================================== */
@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;
  }
  
  .btn-primary:hover .btn-arrow,
  .btn-secondary:hover .btn-arrow,
  .budget-strip-item:hover,
  .traffic-scale-node:hover {
    transform: none !important;
  }
}