/* ==========================================================================
   青云梯机场 - 视觉设计系统：梁架分层系统 (Beam-and-Frame Layered System)
   Version: 4.0.0
   ========================================================================== */

/* 1. CSS Custom Properties (设计变量) */
:root {
  /* 背景调色盘 */
  --bg-main: #F7F9F7;       /* 80% 主背景：浅冷白 */
  --bg-surface: #FFFFFF;    /* 纯白 */
  --bg-alt: #EEF1EE;        /* 第二背景：浅灰绿 */
  
  /* 文字与排版 */
  --text-main: #1F2728;     /* 主文字：深墨灰 */
  --text-body: #5C6667;     /* 正文文字：中石灰 */
  --text-muted: #899193;    /* 次级文字：浅灰 */
  
  /* 品牌与结构色 (15%) */
  --cyan-structure: #456069;/* 结构青 */
  --cyan-deep: #354D54;     /* 深墨青 */
  --green-pine: #5A6E65;    /* 灰松绿 */
  --green-dark: #485950;    /* 深灰绿 */
  
  /* 强调色 (5%) */
  --brown-warm: #A17A5A;    /* 暖砂棕 */
  --terracotta: #AE6D51;    /* 陶土色 */
  
  /* 浅色填充与辅助 */
  --cyan-light: #EDF1F1;    /* 浅青 */
  --warm-light: #F5EEE7;    /* 浅暖 */
  
  /* 结构线与边框 */
  --border-color: #D9DFDC;  /* 标准细边框 */
  --line-structure: #C8D0CC;/* 结构分界线 */
  --beam-primary: #8FA29B;  /* 一级主梁颜色 */
  --beam-secondary: #AAB7B2;/* 二级分梁颜色 */
  
  /* 字体系统 */
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
  
  /* 布局与圆角 */
  --container-max: 1240px;
  --radius-sm: 2px;
  --radius-md: 4px;
  --radius-lg: 6px;
  
  /* 细微阴影 (基本不使用或极淡) */
  --shadow-subtle: 0 10px 26px rgba(31, 39, 40, 0.02);
}

/* 2. Reset & Universal Styles */
*, *::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(--text-body);
  background-color: var(--bg-main);
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
}

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

main {
  flex: 1;
}

a {
  color: var(--cyan-structure);
  text-decoration: none;
  transition: color 0.2s ease, border-color 0.2s ease;
}

a:hover {
  color: var(--cyan-deep);
}

/* focus-visible 键盘聚焦支持 */
a:focus-visible, button:focus-visible, input:focus-visible, summary:focus-visible {
  outline: 2px solid var(--cyan-structure);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

h1, h2, h3, h4, h5, h6 {
  color: var(--text-main);
  font-weight: 600;
  line-height: 1.35;
  letter-spacing: -0.01em;
}

h1 { font-size: clamp(2.2rem, 4vw, 3.4rem); }
h2 { font-size: clamp(1.6rem, 2.5vw, 2.25rem); }
h3 { font-size: clamp(1.25rem, 1.8vw, 1.5rem); }

p {
  margin-bottom: 1rem;
}

p:last-child {
  margin-bottom: 0;
}

ul, ol {
  list-style: none;
}

/* 3. Header & Navigation (顶部横梁导航) */
.site-header {
  height: 70px;
  background-color: var(--bg-main);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 100;
}

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

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

.logo-svg {
  width: 36px;
  height: 36px;
}

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

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

.brand-sub {
  font-size: 0.75rem;
  color: var(--text-muted);
  letter-spacing: 0.02em;
}

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

.nav-link {
  font-size: 0.9375rem;
  color: var(--text-body);
  padding: 0.5rem 0;
  position: relative;
  font-weight: 500;
}

.nav-link:hover, .nav-link.active {
  color: var(--text-main);
}

.nav-link.active::after {
  content: "";
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 20px;
  height: 2px;
  background-color: var(--cyan-structure);
}

.header-cta {
  display: flex;
  align-items: center;
}

/* 4. Commercial Buttons & Utility Links */
.btn-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  background-color: var(--cyan-structure);
  color: var(--bg-surface);
  padding: 0.6rem 1.25rem;
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: 0.9375rem;
  border: 1px solid var(--cyan-deep);
  cursor: pointer;
  transition: background-color 0.2s ease, transform 0.15s ease;
}

.btn-cta:hover {
  background-color: var(--cyan-deep);
  color: var(--bg-surface);
  transform: translateY(-1px);
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  background-color: transparent;
  color: var(--text-main);
  padding: 0.6rem 1.25rem;
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: 0.9375rem;
  border: 1px solid var(--border-color);
  cursor: pointer;
  transition: background-color 0.2s ease, border-color 0.2s ease;
}

.btn-secondary:hover {
  background-color: var(--bg-alt);
  border-color: var(--line-structure);
  color: var(--text-main);
}

.text-link {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--cyan-structure);
}

.text-link:hover {
  color: var(--cyan-deep);
}

/* Mobile Menu Toggle */
.mobile-menu-btn {
  display: none;
  background: none;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 0.4rem 0.75rem;
  font-size: 0.875rem;
  color: var(--text-main);
  cursor: pointer;
}

/* Mobile Nav Overlay */
.mobile-nav-drawer {
  display: none;
  position: fixed;
  top: 70px;
  left: 0;
  right: 0;
  background-color: var(--bg-surface);
  border-bottom: 2px solid var(--cyan-structure);
  padding: 1.5rem;
  box-shadow: 0 10px 30px rgba(0,0,0,0.08);
  z-index: 99;
}

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

.mobile-nav-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.mobile-nav-link {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-main);
  padding: 0.5rem 0;
  border-bottom: 1px dashed var(--border-color);
}

/* 5. 梁架分层系统 - 核心结构组件 (Beam & Frame Engine) */
.section-beam-frame {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 3.5rem 1.5rem;
}

/* 横向主题梁 (Beam Top Line) */
.beam-top {
  border-top: 2px solid var(--beam-primary);
  padding-top: 1rem;
  margin-bottom: 2rem;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
}

.beam-title-group {
  display: flex;
  align-items: baseline;
  gap: 1rem;
}

.beam-number {
  font-family: monospace, sans-serif;
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--terracotta);
  letter-spacing: 0.05em;
}

.beam-heading {
  font-size: 1.75rem;
  color: var(--text-main);
  margin: 0;
}

.beam-subtext {
  font-size: 0.9375rem;
  color: var(--text-muted);
}

.beam-action {
  font-size: 0.9rem;
  font-weight: 600;
}

/* 纵向信息架 Grid Layout Containers */
.frame-grid {
  display: grid;
  gap: 1.75rem;
  align-items: start;
  position: relative;
}

/* 不等比分区 Grid Ratios */
.frame-grid-46-31-23 { grid-template-columns: 46% 31% 23%; }
.frame-grid-42-36-22 { grid-template-columns: 42% 36% 22%; }
.frame-grid-34-33-33 { grid-template-columns: 34% 33% 33%; }
.frame-grid-58-42    { grid-template-columns: 58% 42%; }
.frame-grid-62-38    { grid-template-columns: 62% 38%; }
.frame-grid-38-31-31 { grid-template-columns: 38% 31% 31%; }
.frame-grid-66-34    { grid-template-columns: 66% 34%; }
.frame-grid-45-32-23 { grid-template-columns: 45% 32% 23%; }
.frame-grid-42-33-25 { grid-template-columns: 42% 33% 25%; }
.frame-grid-36-24-21-19 { grid-template-columns: 36% 24% 21% 19%; }

/* 纵向结构线 (Vertical Frame Lines) - 不覆盖100%以防Excel表格感 */
.frame-col {
  position: relative;
}

.frame-col-bordered {
  padding-left: 1.5rem;
  border-left: 1px solid var(--border-color);
}

.frame-col-subtle {
  padding-left: 1.25rem;
  border-left: 1px dashed var(--line-structure);
}

/* 跨列 Span Rules */
.span-2 {
  grid-column: span 2;
}

.span-full {
  grid-column: 1 / -1;
}

.span-cross-bottom {
  margin-top: 1.5rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--line-structure);
  background-color: var(--bg-alt);
  padding: 1.25rem 1.5rem;
  border-radius: var(--radius-md);
}

/* 6. Section Specific Design System */

/* --- Hero Section --- */
.hero-section {
  background-color: var(--bg-main);
  padding: 3rem 0 4rem 0;
  border-bottom: 1px solid var(--border-color);
}

.hero-beam-top {
  border-top: 3px solid var(--cyan-structure);
  padding-top: 0.75rem;
  margin-bottom: 2.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.hero-beam-meta {
  font-size: 0.875rem;
  color: var(--text-muted);
  font-weight: 600;
  letter-spacing: 0.05em;
}

.hero-col-main {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.hero-kicker {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--terracotta);
  line-height: 1.4;
}

.hero-h1 {
  font-size: clamp(2rem, 3.2vw, 2.8rem);
  color: var(--text-main);
  line-height: 1.25;
}

.hero-desc {
  font-size: 1.0625rem;
  color: var(--text-body);
  line-height: 1.8;
}

.hero-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-top: 0.5rem;
  flex-wrap: wrap;
}

.hero-box-title {
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--cyan-deep);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding-bottom: 0.5rem;
  margin-bottom: 1rem;
  border-bottom: 2px solid var(--cyan-structure);
}

.hero-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.hero-list-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.5rem 0.75rem;
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  font-size: 0.9375rem;
}

.hero-list-item .badge {
  font-size: 0.75rem;
  padding: 0.15rem 0.5rem;
  background-color: var(--cyan-light);
  color: var(--cyan-deep);
  border-radius: var(--radius-sm);
  font-weight: 600;
}

/* Hero 跨列快速入口 */
.hero-cross-entry {
  grid-column: 2 / -1;
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-left: 3px solid var(--brown-warm);
  padding: 1.25rem 1.5rem;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.hero-cross-links {
  display: flex;
  gap: 1.25rem;
  flex-wrap: wrap;
}

.hero-cross-links a {
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--cyan-structure);
}

/* --- Section 01: 套餐结构 --- */
.plan-item-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.85rem 0;
  border-bottom: 1px solid var(--border-color);
}

.plan-item-row:last-child {
  border-bottom: none;
}

.plan-name {
  font-weight: 700;
  color: var(--text-main);
  font-size: 1.05rem;
}

.plan-price {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--cyan-deep);
}

.plan-desc {
  font-size: 0.875rem;
  color: var(--text-muted);
}

/* 主力方案跨列突出 */
.main-plan-featured {
  background-color: var(--bg-alt);
  border: 1px solid var(--border-color);
  border-left: 4px solid var(--green-pine);
  padding: 1.5rem;
  border-radius: var(--radius-md);
  margin-top: 1.25rem;
}

.main-plan-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.75rem;
}

.main-plan-tag {
  background-color: var(--terracotta);
  color: var(--bg-surface);
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.2rem 0.6rem;
  border-radius: var(--radius-sm);
}

.main-plan-price-large {
  font-size: 2.2rem;
  font-weight: 800;
  color: var(--text-main);
  line-height: 1;
}

.main-plan-price-large span {
  font-size: 1rem;
  font-weight: 400;
  color: var(--text-muted);
}

/* --- Section 03: 线路结构比较表 (真实 HTML Table) --- */
.line-table-wrapper {
  overflow-x: auto;
  margin-top: 1.75rem;
  border-top: 2px solid var(--beam-primary);
}

.line-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 0.9375rem;
}

.line-table th {
  background-color: var(--bg-alt);
  color: var(--text-main);
  font-weight: 700;
  padding: 1rem 1.25rem;
  border-bottom: 1px solid var(--border-color);
}

.line-table td {
  padding: 1rem 1.25rem;
  border-bottom: 1px solid var(--border-color);
  color: var(--text-body);
}

.line-table tr:hover td {
  background-color: var(--bg-surface);
}

/* --- Section 06: 完整梁架价目 --- */
.pricing-beam-container {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.pricing-row {
  display: grid;
  grid-template-columns: 80px 160px 140px 140px 1fr auto;
  align-items: center;
  gap: 1rem;
  padding: 1.15rem 1.5rem;
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
}

.pricing-row-featured {
  background-color: var(--bg-alt);
  border: 1px solid var(--green-pine);
  border-left: 5px solid var(--green-pine);
}

.pricing-num {
  font-family: monospace, sans-serif;
  font-weight: 700;
  color: var(--terracotta);
}

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

.pricing-traffic {
  font-weight: 600;
  color: var(--cyan-structure);
}

.pricing-cost {
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--cyan-deep);
}

.pricing-target {
  font-size: 0.875rem;
  color: var(--text-muted);
}

/* --- Section 07 & 08: 深度评测与教程 Beam Layout --- */
.article-beam-card {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-top: 3px solid var(--cyan-structure);
  padding: 1.5rem;
  border-radius: var(--radius-sm);
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.article-beam-card.featured-span {
  background-color: var(--bg-surface);
  border-top: 3px solid var(--terracotta);
}

.article-meta-row {
  display: flex;
  gap: 1rem;
  font-size: 0.8125rem;
  color: var(--text-muted);
}

.article-cat-tag {
  color: var(--brown-warm);
  font-weight: 700;
}

.article-title {
  font-size: 1.25rem;
  color: var(--text-main);
  line-height: 1.4;
}

.article-summary {
  font-size: 0.9375rem;
  color: var(--text-body);
  line-height: 1.7;
}

/* --- Section 10: FAQ 梁架 Accordion --- */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.faq-item {
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 0.85rem;
}

.faq-question {
  width: 100%;
  text-align: left;
  background: none;
  border: none;
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-main);
  padding: 0.5rem 0;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.faq-toggle-icon {
  font-size: 1.2rem;
  color: var(--cyan-structure);
  transition: transform 0.2s ease;
}

.faq-item.open .faq-toggle-icon {
  transform: rotate(45deg);
}

.faq-answer {
  display: none;
  padding: 0.75rem 0 0.5rem 0;
  font-size: 0.9375rem;
  color: var(--text-body);
  line-height: 1.8;
}

.faq-item.open .faq-answer {
  display: block;
}

/* 7. Footer Design (梁架Footer) */
.site-footer {
  background-color: var(--bg-alt);
  border-top: 2px solid var(--border-color);
  padding: 3.5rem 0 2rem 0;
  color: var(--text-body);
  font-size: 0.9rem;
}

.footer-container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 36% 24% 21% 19%;
  gap: 2rem;
  padding-bottom: 2.5rem;
  border-bottom: 1px solid var(--border-color);
}

.footer-col-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 1rem;
  padding-bottom: 0.35rem;
  border-bottom: 2px solid var(--beam-primary);
  display: inline-block;
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

.footer-links a {
  color: var(--text-body);
  font-size: 0.875rem;
}

.footer-links a:hover {
  color: var(--text-main);
}

.footer-bottom {
  padding-top: 1.75rem;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  font-size: 0.8125rem;
  color: var(--text-muted);
}

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

.friend-links a {
  color: var(--text-body);
  font-weight: 500;
}

/* 8. Article & Content Pages Layout (文章与分类页) */
.article-page-container {
  max-width: 1000px;
  margin: 0 auto;
  padding: 3rem 1.5rem 5rem 1.5rem;
}

.breadcrumb {
  display: flex;
  gap: 0.5rem;
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
}

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

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

.article-hero-beam {
  border-top: 3px solid var(--cyan-structure);
  padding-top: 1.25rem;
  margin-bottom: 2.5rem;
  display: grid;
  grid-template-columns: 70% 30%;
  gap: 2rem;
}

.article-header-main h1 {
  font-size: clamp(1.8rem, 3vw, 2.5rem);
  margin-bottom: 1rem;
  line-height: 1.3;
}

.article-excerpt {
  font-size: 1.0625rem;
  color: var(--text-body);
  line-height: 1.8;
  background-color: var(--bg-alt);
  padding: 1rem 1.25rem;
  border-left: 3px solid var(--brown-warm);
  border-radius: var(--radius-sm);
}

.article-meta-side {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  font-size: 0.875rem;
  color: var(--text-muted);
  border-left: 1px solid var(--border-color);
  padding-left: 1.25rem;
}

.quick-conclusion-box {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-top: 3px solid var(--green-pine);
  padding: 1.5rem;
  border-radius: var(--radius-sm);
  margin-bottom: 2.5rem;
}

.quick-conclusion-title {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 0.5rem;
}

.article-content-layout {
  display: grid;
  grid-template-columns: 1fr 240px;
  gap: 2.5rem;
  align-items: start;
}

.article-body {
  max-width: 780px;
  font-size: 1.0625rem;
  line-height: 1.85;
  color: var(--text-main);
}

.article-body h2 {
  font-size: 1.6rem;
  margin: 2.5rem 0 1rem 0;
  padding-top: 1.25rem;
  border-top: 2px solid var(--line-structure);
  position: relative;
}

.article-body h2::before {
  content: "";
  position: absolute;
  top: -2px;
  left: 0;
  width: 60px;
  height: 2px;
  background-color: var(--terracotta);
}

.article-body h3 {
  font-size: 1.25rem;
  margin: 1.75rem 0 0.75rem 0;
  color: var(--cyan-deep);
}

.article-body p {
  margin-bottom: 1.25rem;
}

.article-body ul, .article-body ol {
  margin-bottom: 1.5rem;
  padding-left: 1.5rem;
}

.article-body li {
  margin-bottom: 0.5rem;
  list-style-type: disc;
}

.article-toc {
  position: sticky;
  top: 90px;
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  padding: 1.25rem;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
}

.toc-title {
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 0.75rem;
  padding-bottom: 0.35rem;
  border-bottom: 1px solid var(--border-color);
}

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

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

.toc-list a:hover {
  color: var(--cyan-structure);
}

.related-articles-section {
  margin-top: 3.5rem;
  padding-top: 2rem;
  border-top: 2px solid var(--beam-primary);
}

/* Category Page Specific */
.category-hero-beam {
  border-top: 3px solid var(--cyan-structure);
  padding-top: 1.25rem;
  margin-bottom: 2.5rem;
  display: grid;
  grid-template-columns: 65% 35%;
  gap: 2rem;
}

/* 9. Responsive Breakpoints (响应式适配) */

/* 1024px 以下 Tablet */
@media (max-width: 1024px) {
  .pricing-row {
    grid-template-columns: 60px 140px 120px 120px 1fr;
  }
  .pricing-row .btn-cta {
    grid-column: 1 / -1;
    margin-top: 0.5rem;
  }
}

/* 768px 以下 Mobile Phone */
@media (max-width: 768px) {
  .nav-desktop, .header-cta {
    display: none;
  }
  
  .mobile-menu-btn {
    display: block;
  }

  .beam-top {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.5rem;
  }

  /* 核心梁架多列转单列 */
  .frame-grid-46-31-23,
  .frame-grid-42-36-22,
  .frame-grid-34-33-33,
  .frame-grid-58-42,
  .frame-grid-62-38,
  .frame-grid-38-31-31,
  .frame-grid-66-34,
  .frame-grid-45-32-23,
  .frame-grid-42-33-25,
  .frame-grid-36-24-21-19,
  .article-hero-beam,
  .category-hero-beam,
  .article-content-layout,
  .footer-grid {
    grid-template-columns: 1fr !important;
  }

  .frame-col-bordered, .frame-col-subtle {
    padding-left: 0;
    border-left: none;
    border-top: 1px dashed var(--line-structure);
    padding-top: 1.25rem;
  }

  .span-2, .hero-cross-entry {
    grid-column: 1 / -1 !important;
  }

  .pricing-row {
    grid-template-columns: 1fr;
    gap: 0.5rem;
  }

  .article-toc {
    display: none; /* 移动端默认隐藏 Sticky TOC */
  }

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
  }
}

/* 10. prefers-reduced-motion (减弱动画规范) */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  *, *::before, *::after {
    animation: none !important;
    transition: none !important;
  }
}