:root {
  --bg: #F8F8F4;
  --surface: #FFFFFF;
  --bg-alt: #F1EFE9;
  --text: #202629;
  --text-body: #5D6568;
  --muted: #898F91;
  --blue: #415C65;
  --blue-dark: #314A52;
  --green: #566A61;
  --green-dark: #44544C;
  --warm: #A87955;
  --terracotta: #B06E50;
  --bg-cream: #F3EEE6;
  --bg-green-light: #EEF1EE;
  --bg-blue-light: #EDF1F2;
  --border: #E0DDD6;
  --footer-text: #4C5558;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
  --max-w: 1200px;
}

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  background-color: var(--bg);
  color: var(--text-body);
  font-family: var(--font-sans);
  -webkit-text-size-adjust: 100%;
}

body {
  background-color: var(--bg);
  color: var(--text-body);
  font-size: 16px;
  line-height: 1.8;
  overflow-x: hidden;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

main {
  flex: 1;
}

a {
  color: var(--blue-dark);
  text-decoration: none;
  transition: color 0.18s ease, background-color 0.18s ease, border-color 0.18s ease;
}

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

a:focus-visible,
button:focus-visible,
summary:focus-visible {
  outline: 2px solid var(--green);
  outline-offset: 2px;
  border-radius: 2px;
}

ul, ol {
  list-style: none;
}

.container {
  width: 100%;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
}

/* Typography Scale */
h1, h2, h3, h4 {
  color: var(--text);
  font-weight: 600;
  line-height: 1.32;
  letter-spacing: -0.01em;
}

h1 {
  font-size: clamp(28px, 3.4vw, 46px);
}

h2 {
  font-size: clamp(22px, 2.5vw, 32px);
}

h3 {
  font-size: clamp(18px, 1.8vw, 22px);
}

.config-num {
  font-size: 14px;
  font-weight: 600;
  color: var(--warm);
  letter-spacing: 0.04em;
  font-variant-numeric: tabular-nums;
}

/* ==================================================
   Header (66px - 72px)
   ================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: 68px;
  background-color: var(--bg);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.brand-link {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  flex-shrink: 0;
}

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

.brand-logo {
  flex-shrink: 0;
  display: block;
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
}

.brand-name {
  font-size: 17px;
  font-weight: 700;
  color: var(--text);
  letter-spacing: 0.01em;
}

.brand-sub {
  font-size: 11px;
  color: var(--muted);
  margin-top: 2px;
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 18px;
}

.nav-link {
  position: relative;
  font-size: 14px;
  color: var(--text-body);
  padding: 6px 2px;
  white-space: nowrap;
  font-weight: 500;
}

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

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

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

.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}

.btn-primary,
.btn-secondary,
.btn-text {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  font-size: 14px;
  font-weight: 600;
  border-radius: 4px;
  cursor: pointer;
  transition: background-color 0.18s ease, color 0.18s ease, border-color 0.18s ease;
  white-space: nowrap;
}

.btn-primary {
  background-color: var(--blue-dark);
  color: var(--surface);
  padding: 8px 16px;
  border: 1px solid var(--blue-dark);
}

.btn-primary:hover {
  background-color: var(--green-dark);
  border-color: var(--green-dark);
  color: var(--surface);
}

.btn-secondary {
  background-color: var(--surface);
  color: var(--text);
  padding: 8px 16px;
  border: 1px solid var(--border);
}

.btn-secondary:hover {
  background-color: var(--bg-cream);
  border-color: var(--warm);
  color: var(--text);
}

.btn-text {
  color: var(--blue-dark);
  padding: 6px 4px;
  font-weight: 600;
}

.btn-text:hover {
  color: var(--warm);
}

.arrow-icon {
  display: inline-block;
  transition: transform 0.18s ease;
}

.btn-primary:hover .arrow-icon,
.btn-secondary:hover .arrow-icon,
.btn-text:hover .arrow-icon,
.article-more:hover .arrow-icon {
  transform: translateX(3px);
}

.mobile-menu-toggle {
  display: none;
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text);
  font-size: 14px;
  font-weight: 600;
  padding: 6px 12px;
  border-radius: 4px;
  cursor: pointer;
}

.mobile-nav-drawer {
  display: none;
  background-color: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 16px 24px 20px;
}

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

.mobile-nav-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 8px 16px;
  margin-bottom: 16px;
}

.mobile-nav-list a {
  display: block;
  padding: 8px 10px;
  font-size: 14px;
  color: var(--text);
  background-color: var(--bg);
  border: 1px solid var(--border);
  border-radius: 4px;
}

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

/* ==================================================
   Hero: Complete Configuration Sheet (660px - 760px Desktop)
   ================================================== */
.hero-section {
  padding: 20px 0 28px;
}

.config-sheet-hero {
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-radius: 6px;
  overflow: hidden;
}

.hero-sheet-top {
  padding: 26px 32px 22px;
  border-bottom: 1px solid var(--border);
  background: linear-gradient(180deg, var(--bg-cream) 0%, var(--surface) 100%);
}

.hero-meta-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 10px;
}

.hero-tag {
  display: inline-block;
  font-size: 13px;
  font-weight: 600;
  color: var(--green-dark);
  background-color: var(--bg-green-light);
  padding: 2px 10px;
  border-radius: 3px;
  border: 1px solid #D5DFD7;
}

.hero-brand-label {
  font-size: 13px;
  font-weight: 600;
  color: var(--warm);
  letter-spacing: 0.04em;
}

.hero-lead-slogan {
  font-size: 17px;
  font-weight: 600;
  color: var(--blue-dark);
  margin-bottom: 6px;
}

.hero-h1 {
  font-size: clamp(26px, 3.2vw, 44px);
  color: var(--text);
  margin-bottom: 10px;
  line-height: 1.26;
}

.hero-desc {
  font-size: 16px;
  color: var(--text-body);
  max-width: 920px;
  line-height: 1.75;
  margin-bottom: 16px;
}

.hero-cta-row {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
}

/* 4 Configuration Steps inside Shared Sheet */
.hero-steps-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
}

.hero-step-cell {
  padding: 20px 32px;
  border-bottom: 1px solid var(--border);
  transition: background-color 0.18s ease;
}

.hero-step-cell:nth-child(odd) {
  border-right: 1px solid var(--border);
}

.hero-step-cell:hover {
  background-color: #FAF9F6;
}

.step-header {
  display: flex;
  align-items: baseline;
  gap: 10px;
  margin-bottom: 8px;
}

.step-number {
  font-size: 14px;
  font-weight: 700;
  color: var(--warm);
  background-color: var(--bg-cream);
  padding: 1px 7px;
  border-radius: 3px;
}

.step-question {
  font-size: 16px;
  font-weight: 600;
  color: var(--text);
}

.step-options-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px 14px;
  padding: 7px 12px;
  background-color: var(--bg);
  border-left: 2px solid var(--blue);
  margin-bottom: 6px;
}

.step-opt-item {
  font-size: 14px;
  color: var(--text);
  font-weight: 500;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.step-opt-item small {
  font-size: 12px;
  color: var(--muted);
  font-weight: 400;
}

.step-opt-sep {
  color: var(--border);
  font-size: 12px;
}

.step-note {
  font-size: 13px;
  color: var(--muted);
  line-height: 1.5;
}

/* Hero Sheet Bottom Bar */
.hero-sheet-bottom {
  padding: 14px 28px;
  background-color: var(--bg-green-light);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}

.hero-bottom-info {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
}

.hero-bottom-badge {
  font-size: 13px;
  font-weight: 700;
  color: var(--surface);
  background-color: var(--green);
  padding: 2px 9px;
  border-radius: 3px;
}

.hero-bottom-text {
  font-size: 14px;
  color: var(--text);
  font-weight: 500;
}

/* ==================================================
   Section Structure & Common Headers
   ================================================== */
.config-section {
  padding: 48px 0;
  border-top: 1px solid var(--border);
}

.config-section--alt {
  background-color: var(--bg-alt);
}

.section-head {
  margin-bottom: 24px;
}

.section-index {
  display: inline-block;
  font-size: 14px;
  font-weight: 700;
  color: var(--warm);
  letter-spacing: 0.05em;
  margin-bottom: 6px;
}

.section-title {
  margin-bottom: 12px;
}

.section-direct-answer {
  font-size: 16px;
  color: var(--text);
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-left: 3px solid var(--green);
  padding: 14px 18px;
  border-radius: 4px;
  max-width: 920px;
  line-height: 1.75;
}

/* ==================================================
   01 / 流量选择 & 02 / 用途选择 (Config List Rows)
   ================================================== */
.sheet-box {
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-radius: 6px;
  overflow: hidden;
}

.sheet-row {
  display: grid;
  grid-template-columns: 180px 1.2fr 1.3fr;
  gap: 20px;
  padding: 18px 24px;
  border-bottom: 1px solid var(--border);
  align-items: baseline;
  transition: background-color 0.15s ease;
}

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

.sheet-row:hover {
  background-color: #FAF9F5;
}

.sheet-row--header {
  background-color: var(--bg-cream);
  font-size: 13px;
  font-weight: 600;
  color: var(--blue-dark);
  padding: 12px 24px;
}

.sheet-row--header:hover {
  background-color: var(--bg-cream);
}

.sheet-cell-title {
  display: flex;
  align-items: baseline;
  gap: 8px;
  font-weight: 600;
  color: var(--text);
  font-size: 16px;
}

.sheet-cell-body {
  font-size: 15px;
  color: var(--text-body);
}

.sheet-cell-focus {
  font-size: 14px;
  color: var(--text-body);
}

/* Usage List (3 columns: Usage | Focus | Related Link) */
.sheet-row--usage {
  grid-template-columns: 160px 1fr 210px;
}

/* ==================================================
   03 / 地区选择 & 04 / 线路理解
   ================================================== */
.region-summary-list,
.line-summary-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-radius: 6px;
  margin-bottom: 24px;
}

.region-summary-item,
.line-summary-item {
  padding: 18px 24px;
  border-bottom: 1px solid var(--border);
}

.region-summary-item:nth-child(odd),
.line-summary-item:nth-child(odd) {
  border-right: 1px solid var(--border);
}

.region-summary-item:nth-last-child(-n+2),
.line-summary-item:nth-last-child(-n+2) {
  border-bottom: none;
}

.item-head {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 6px;
}

.item-head h3 {
  font-size: 18px;
}

/* Lightweight HTML Table */
.config-table-wrap {
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-radius: 6px;
  overflow: hidden;
}

.config-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
}

.config-table th {
  background-color: var(--bg-cream);
  color: var(--blue-dark);
  font-size: 13px;
  font-weight: 600;
  padding: 13px 20px;
  border-bottom: 1px solid var(--border);
}

.config-table td {
  padding: 16px 20px;
  border-bottom: 1px solid var(--border);
  font-size: 15px;
  color: var(--text-body);
  vertical-align: top;
}

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

.config-table tr:hover td {
  background-color: #FAF9F5;
}

.config-table td strong {
  color: var(--text);
  font-weight: 600;
}

/* ==================================================
   05 / 设备选择
   ================================================== */
.device-sheet-row {
  display: grid;
  grid-template-columns: 160px 1fr 1fr 1fr 150px;
  gap: 16px;
  padding: 18px 24px;
  border-bottom: 1px solid var(--border);
  align-items: start;
}

.device-sheet-row:last-child {
  border-bottom: none;
}

.device-field-label {
  display: none;
  font-size: 12px;
  font-weight: 600;
  color: var(--muted);
  margin-bottom: 2px;
}

/* ==================================================
   06 / 推荐组合 (Single Combination Sheet)
   ================================================== */
.combo-disclaimer {
  font-size: 14px;
  color: var(--blue-dark);
  background-color: var(--bg-blue-light);
  border: 1px solid var(--border);
  padding: 10px 16px;
  border-radius: 4px;
  margin-bottom: 16px;
}

.combo-row {
  display: grid;
  grid-template-columns: 210px 130px 1.2fr 1.1fr 1fr;
  gap: 16px;
  padding: 18px 24px;
  border-bottom: 1px solid var(--border);
  align-items: baseline;
}

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

.combo-row--featured {
  background-color: var(--bg-green-light);
  border-left: 3px solid var(--green);
}

.badge-priority {
  display: inline-block;
  font-size: 12px;
  font-weight: 600;
  color: var(--surface);
  background-color: var(--warm);
  padding: 1px 7px;
  border-radius: 3px;
  margin-left: 6px;
}

/* ==================================================
   07 / 完整套餐 (Configuration Price Sheet)
   ================================================== */
.plan-sheet {
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-radius: 6px;
  overflow: hidden;
}

.plan-row {
  display: grid;
  grid-template-columns: 180px 120px 140px 1.2fr 1fr 140px;
  gap: 16px;
  padding: 20px 24px;
  border-bottom: 1px solid var(--border);
  align-items: center;
}

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

.plan-row:nth-child(even):not(.plan-row--main) {
  background-color: #FBFAF7;
}

.plan-row--header {
  background-color: var(--bg-cream);
  font-size: 13px;
  font-weight: 600;
  color: var(--blue-dark);
  padding: 12px 24px;
}

.plan-row--main {
  background-color: var(--bg-green-light);
  border-left: 3px solid var(--green);
}

.plan-name-wrap {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.plan-name {
  font-size: 17px;
  font-weight: 700;
  color: var(--text);
}

.plan-badge-warm {
  display: inline-block;
  align-self: flex-start;
  font-size: 12px;
  font-weight: 600;
  color: var(--surface);
  background-color: var(--warm);
  padding: 1px 8px;
  border-radius: 3px;
}

.plan-traffic {
  font-size: 16px;
  font-weight: 600;
  color: var(--blue-dark);
}

.plan-price {
  font-size: 32px;
  font-weight: 700;
  color: var(--text);
  line-height: 1.1;
}

.plan-price small {
  font-size: 14px;
  font-weight: 400;
  color: var(--muted);
}

.plan-note {
  font-size: 13px;
  color: var(--muted);
  margin-top: 12px;
}

/* ==================================================
   08 / 拼好连机场深度评测入口
   ================================================== */
.review-sheet {
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 28px;
}

.review-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin: 20px 0 24px;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding: 18px 0;
}

.review-dim-item h3 {
  font-size: 16px;
  margin-bottom: 6px;
}

.review-dim-item p {
  font-size: 14px;
  color: var(--text-body);
}

/* ==================================================
   09 / 内容中心 (Content Configuration Directory)
   ================================================== */
.content-dir-sheet {
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-radius: 6px;
  overflow: hidden;
}

.content-dir-group {
  display: grid;
  grid-template-columns: 160px 240px 1fr;
  border-bottom: 1px solid var(--border);
}

.content-dir-group:last-child {
  border-bottom: none;
}

.dir-cat-col {
  padding: 22px 20px;
  background-color: var(--bg-cream);
  border-right: 1px solid var(--border);
}

.dir-cat-title {
  font-size: 17px;
  font-weight: 700;
  color: var(--text);
  margin-top: 4px;
}

.dir-desc-col {
  padding: 22px 20px;
  border-right: 1px solid var(--border);
  font-size: 14px;
  color: var(--text-body);
}

.dir-articles-col {
  display: flex;
  flex-direction: column;
}

.dir-article-item {
  padding: 18px 24px;
  border-bottom: 1px solid var(--border);
  transition: background-color 0.15s ease;
}

.dir-article-item:last-child {
  border-bottom: none;
}

.dir-article-item:hover {
  background-color: #FAF9F5;
}

.article-meta-top {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
  font-size: 12px;
  color: var(--muted);
  margin-bottom: 4px;
}

.article-cat-tag {
  color: var(--green-dark);
  background-color: var(--bg-green-light);
  padding: 1px 7px;
  border-radius: 3px;
  font-weight: 600;
}

.dir-article-title {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 6px;
}

.dir-article-title a {
  color: var(--text);
}

.dir-article-title a:hover {
  color: var(--warm);
}

.dir-article-excerpt {
  font-size: 14px;
  color: var(--text-body);
  margin-bottom: 8px;
}

.article-more {
  font-size: 13px;
  font-weight: 600;
  color: var(--blue-dark);
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

/* ==================================================
   10 / 网络排障检查单 (01 - 07)
   ================================================== */
.trouble-row {
  display: grid;
  grid-template-columns: 70px 180px 1fr 1.2fr;
  gap: 16px;
  padding: 16px 24px;
  border-bottom: 1px solid var(--border);
  align-items: baseline;
}

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

.trouble-row--header {
  background-color: var(--bg-cream);
  font-size: 13px;
  font-weight: 600;
  color: var(--blue-dark);
  padding: 12px 24px;
}

/* ==================================================
   11 / FAQ 问题清单
   ================================================== */
.faq-list {
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-radius: 6px;
}

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

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

.faq-trigger {
  width: 100%;
  background: none;
  border: none;
  padding: 16px 24px;
  display: grid;
  grid-template-columns: 48px 1fr 32px;
  align-items: center;
  text-align: left;
  cursor: pointer;
  color: var(--text);
  font-family: inherit;
  transition: background-color 0.15s ease;
}

.faq-trigger:hover {
  background-color: #FAF9F5;
}

.faq-q-text {
  font-size: 16px;
  font-weight: 600;
  color: var(--text);
}

.faq-icon {
  font-size: 18px;
  font-weight: 600;
  color: var(--warm);
  text-align: right;
  transition: transform 0.18s ease;
}

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

.faq-answer {
  padding: 0 24px 18px 72px;
  font-size: 15px;
  color: var(--text-body);
  line-height: 1.78;
}

.js-enabled .faq-item:not(.is-open) .faq-answer {
  display: none;
}

/* ==================================================
   Article & Category Pages Layout
   ================================================== */
.breadcrumb-bar {
  padding: 14px 0;
  border-bottom: 1px solid var(--border);
  background-color: var(--bg-alt);
  font-size: 13px;
  color: var(--muted);
}

.breadcrumb-list {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
}

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

.breadcrumb-list a:hover {
  color: var(--warm);
}

/* Category Hero (220px - 320px) */
.category-hero {
  background-color: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 20px 0 22px;
}

.category-hero h1 {
  font-size: clamp(24px, 2.8vw, 36px);
}

.category-hero > .container > p {
  font-size: 14px;
  line-height: 1.6;
  margin-top: 6px !important;
}

.category-summary-sheet {
  border: 1px solid var(--border);
  background-color: var(--bg);
  border-radius: 6px;
  padding: 12px 18px;
  margin-top: 12px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.category-summary-item h2,
.category-summary-item h3 {
  font-size: 14px;
  color: var(--blue-dark);
  margin-bottom: 2px;
}

.category-summary-item p {
  font-size: 13px;
  line-height: 1.5;
  color: var(--text-body);
}

/* Article Page Layout */
.article-page-wrap {
  padding: 36px 0 56px;
}

.article-layout {
  display: grid;
  grid-template-columns: minmax(0, 800px) 230px;
  gap: 36px;
  justify-content: center;
  align-items: start;
}

.article-main {
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 36px 42px;
  max-width: 820px;
}

.article-header {
  border-bottom: 1px solid var(--border);
  padding-bottom: 22px;
  margin-bottom: 24px;
}

.article-meta-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  font-size: 13px;
  color: var(--muted);
  margin: 12px 0 16px;
}

.article-read-config {
  background-color: var(--bg);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 12px 16px;
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  font-size: 13px;
  color: var(--text-body);
}

.article-read-config strong {
  color: var(--text);
}

.quick-conclusion-box {
  background-color: var(--bg-green-light);
  border: 1px solid #D3DDD5;
  border-left: 4px solid var(--green);
  border-radius: 4px;
  padding: 18px 22px;
  margin-bottom: 28px;
}

.quick-conclusion-title {
  font-size: 15px;
  font-weight: 700;
  color: var(--green-dark);
  margin-bottom: 6px;
}

.quick-conclusion-box p {
  font-size: 15px;
  color: var(--text);
  margin: 0;
}

.article-content h2 {
  font-size: 24px;
  margin: 34px 0 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border);
}

.article-content h3 {
  font-size: 19px;
  margin: 22px 0 8px;
}

.article-content p {
  font-size: 16px;
  line-height: 1.85;
  color: var(--text-body);
  margin-bottom: 16px;
}

.article-content ul,
.article-content ol {
  margin: 0 0 18px 20px;
}

.article-content ul li {
  list-style: disc;
  margin-bottom: 8px;
}

.article-content ol li {
  list-style: decimal;
  margin-bottom: 8px;
}

.article-callout {
  background-color: var(--bg-cream);
  border-left: 3px solid var(--warm);
  padding: 14px 18px;
  margin: 20px 0;
  font-size: 15px;
  color: var(--text);
}

.article-Nav-bottom {
  margin-top: 36px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}

.article-nav-card {
  display: block;
  padding: 14px 18px;
  background-color: var(--bg);
  border: 1px solid var(--border);
  border-radius: 4px;
}

.article-nav-card span {
  display: block;
  font-size: 12px;
  color: var(--muted);
  margin-bottom: 4px;
}

.article-nav-card strong {
  font-size: 15px;
  color: var(--text);
}

.article-related-box {
  margin-top: 28px;
  padding: 20px 24px;
  background-color: var(--bg);
  border: 1px solid var(--border);
  border-radius: 4px;
}

.article-related-box h3 {
  font-size: 17px;
  margin-bottom: 12px;
}

.article-related-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 10px 20px;
}

.article-related-list a {
  font-size: 14px;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

/* Sidebar TOC (220px - 240px) */
.article-toc-aside {
  position: sticky;
  top: 88px;
  width: 230px;
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 18px;
}

.toc-title {
  font-size: 14px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 10px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border);
}

.toc-list {
  display: flex;
  flex-direction: column;
  gap: 6px;
  max-height: 70vh;
  overflow-y: auto;
}

.toc-list a {
  font-size: 13px;
  color: var(--text-body);
  line-height: 1.45;
  display: block;
  padding: 3px 0;
}

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

.mobile-toc-details {
  display: none;
  background-color: var(--bg);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 12px 16px;
  margin-bottom: 22px;
}

.mobile-toc-details summary {
  font-size: 14px;
  font-weight: 600;
  color: var(--text);
  cursor: pointer;
}

/* ==================================================
   Footer (Compact 250px - 320px Desktop)
   ================================================== */
.site-footer {
  background-color: var(--bg-alt);
  color: var(--footer-text);
  border-top: 1px solid var(--border);
  padding: 26px 0 20px;
  font-size: 13px;
}

.footer-top-grid {
  display: grid;
  grid-template-columns: 1.4fr repeat(4, 1fr);
  gap: 24px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--border);
}

.footer-brand-desc {
  font-size: 13px;
  color: var(--footer-text);
  margin: 8px 0 12px;
}

.footer-col-title {
  font-size: 13px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 6px;
}

.footer-col-num {
  font-size: 12px;
  color: var(--warm);
  font-weight: 700;
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 5px;
}

.footer-links a {
  color: var(--footer-text);
  font-size: 13px;
  line-height: 1.5;
}

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

.footer-bottom-bar {
  padding-top: 14px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}

.footer-copy {
  order: 1;
  color: var(--footer-text);
}

.footer-friend-links {
  order: 2;
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 14px;
}

.footer-friend-links span {
  color: var(--muted);
}

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

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

/* ==================================================
   Responsive Design (1024px, 768px, 430px, 390px, 375px)
   ================================================== */
@media (max-width: 1080px) {
  .main-nav {
    display: none;
  }
  .mobile-menu-toggle {
    display: inline-flex;
  }
  .article-layout {
    grid-template-columns: 1fr;
  }
  .article-toc-aside {
    display: none;
  }
  .mobile-toc-details {
    display: block;
  }
  .content-dir-group {
    grid-template-columns: 180px 1fr;
  }
  .dir-desc-col {
    display: none;
  }
}

@media (max-width: 768px) {
  .container {
    padding: 0 16px;
  }

  .header-actions .btn-primary {
    display: none;
  }

  /* Mobile Hero: Single Column in exact required sequence */
  .hero-sheet-top {
    padding: 20px 18px;
  }

  .hero-steps-grid {
    grid-template-columns: 1fr;
  }

  .hero-step-cell {
    padding: 16px 18px;
  }

  .hero-step-cell:nth-child(odd) {
    border-right: none;
  }

  .hero-sheet-bottom {
    padding: 16px 18px;
    flex-direction: column;
    align-items: flex-start;
  }

  /* All Config Sheets -> Vertical Single Column */
  .sheet-row,
  .sheet-row--usage,
  .device-sheet-row,
  .combo-row,
  .trouble-row {
    grid-template-columns: 1fr;
    gap: 8px;
    padding: 16px 18px;
  }

  .sheet-row--header,
  .plan-row--header,
  .trouble-row--header {
    display: none;
  }

  .device-field-label {
    display: inline-block;
    margin-right: 6px;
  }

  .region-summary-list,
  .line-summary-list {
    grid-template-columns: 1fr;
  }

  .region-summary-item:nth-child(odd),
  .line-summary-item:nth-child(odd) {
    border-right: none;
  }

  .region-summary-item:nth-last-child(2),
  .line-summary-item:nth-last-child(2) {
    border-bottom: 1px solid var(--border);
  }

  /* Responsive HTML Tables -> Block Layout on Mobile (No horizontal overflow) */
  .config-table,
  .config-table thead,
  .config-table tbody,
  .config-table tr,
  .config-table td {
    display: block;
    width: 100%;
  }

  .config-table thead {
    display: none;
  }

  .config-table tr {
    padding: 14px 18px;
    border-bottom: 1px solid var(--border);
  }

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

  .config-table td {
    padding: 4px 0;
    border-bottom: none;
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
  }

  .config-table td::before {
    content: attr(data-label) "：";
    font-weight: 600;
    color: var(--blue-dark);
    flex-shrink: 0;
  }

  /* Mobile Plans: Custom order (主力 -> 日常 -> 轻量 -> 高频 -> 长期) */
  .plan-sheet {
    display: flex;
    flex-direction: column;
  }

  .plan-row {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
    padding: 18px;
  }

  .plan-row--main { order: 1; }
  .plan-row--daily { order: 2; }
  .plan-row--light { order: 3; }
  .plan-row--high { order: 4; }
  .plan-row--long { order: 5; }

  .review-grid,
  .category-summary-sheet,
  .article-related-list,
  .article-Nav-bottom {
    grid-template-columns: 1fr;
  }

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

  .dir-cat-col {
    border-right: none;
    border-bottom: 1px solid var(--border);
    padding: 14px 18px;
  }

  .dir-article-item {
    padding: 16px 18px;
  }

  .article-main {
    padding: 22px 18px;
  }

  .faq-trigger {
    padding: 14px 16px;
    grid-template-columns: 36px 1fr 24px;
  }

  .faq-answer {
    padding: 0 16px 16px 52px;
  }

  /* Mobile Footer Order: Brand -> 01 -> 02 -> 03 -> 04 -> Friend Links -> Copyright */
  .footer-top-grid {
    grid-template-columns: 1fr;
    gap: 18px;
  }

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

  .footer-friend-links {
    order: 1;
  }

  .footer-copy {
    order: 2;
  }
}

@media (max-width: 430px) {
  .mobile-nav-list {
    grid-template-columns: 1fr;
  }
  .hero-cta-row {
    flex-direction: column;
    align-items: stretch;
  }
  .hero-cta-row a {
    width: 100%;
  }
}

@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 .arrow-icon,
  .btn-secondary:hover .arrow-icon,
  .btn-text:hover .arrow-icon,
  .article-more:hover .arrow-icon {
    transform: none !important;
  }
}