/* ==================================================
   青云梯机场 - 第3套“字阶排版系统” (Typography Scale System)
   CSS Stylesheet
   ================================================== */

:root {
  /* Color Palette - 82% Light/Warm White/Gray, 13% Dark Cyan/Text, 5% Warm Brown/Terracotta */
  --bg: #FCFBF8;
  --bg-white: #FFFFFF;
  --bg-subtle: #F2F0EA;
  --text: #1E2426;
  --text-body: #596265;
  --text-muted: #858D8F;
  --cyan-dark: #405D66;
  --cyan-dark2: #314B53;
  --green-cyan: #5C7168;
  --green-dark: #495B53;
  --warm-brown: #9F7858;
  --terracotta: #AC6C50;
  --light-cyan-gray: #EEF1F1;
  --light-green: #EEF1ED;
  --light-warm: #F5EEE7;
  --border: #DFDED8;

  /* Decorative Large Typography Color */
  --bg-giant-text: rgba(64, 93, 102, 0.07);

  /* Typography Scale */
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
  --line-height-body: 1.8;
  --line-height-heading: 1.25;

  /* Max Widths */
  --site-max-width: 1200px;
  --article-max-width: 780px;
}

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

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

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background-color: var(--bg);
  overflow-x: hidden;
}

/* Links & Buttons */
a {
  color: var(--cyan-dark);
  text-decoration: none;
  transition: color 0.2s ease, text-decoration-color 0.2s ease;
}

a:hover {
  color: var(--cyan-dark2);
  text-decoration: underline;
  text-underline-offset: 4px;
}

button {
  font-family: inherit;
  font-size: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

:focus-visible {
  outline: 2px solid var(--warm-brown);
  outline-offset: 3px;
}

/* Typography Headings */
h1, h2, h3, h4, h5, h6 {
  color: var(--text);
  font-weight: 700;
  line-height: var(--line-height-heading);
  letter-spacing: -0.01em;
}

h1 {
  font-size: clamp(34px, 5vw, 56px);
  margin-bottom: 1.2rem;
}

h2 {
  font-size: clamp(26px, 3.5vw, 38px);
  margin-bottom: 1rem;
}

h3 {
  font-size: clamp(19px, 2.5vw, 24px);
  margin-bottom: 0.8rem;
}

p {
  margin-bottom: 1.2rem;
  font-size: 1.0625rem; /* 17px */
}

/* Horizontal Rule */
hr, .thin-divider {
  border: none;
  border-top: 1px solid var(--border);
  margin: 2.5rem 0;
}

/* Layout Containers */
.container {
  width: 100%;
  max-width: var(--site-max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.article-container {
  width: 100%;
  max-width: var(--article-max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Header Navbar */
.site-header {
  height: 70px;
  background-color: var(--bg);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 1000;
}

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

/* Logo: Qing/Yun/Ti Baseline shift + QYT icon */
.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--text);
  font-weight: 700;
  text-decoration: none !important;
}

.logo-symbol {
  width: 24px;
  height: 24px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.logo-text-wrap {
  display: flex;
  flex-direction: column;
}

.logo-brand-name {
  font-size: 1.125rem;
  letter-spacing: 0.02em;
  display: flex;
  align-items: baseline;
}

/* Baseline Shifts for Logo */
.logo-brand-name .char-qing {
  transform: translateY(0px);
  color: var(--cyan-dark);
}
.logo-brand-name .char-yun {
  transform: translateY(-2px);
  color: var(--green-cyan);
}
.logo-brand-name .char-ti {
  transform: translateY(-4px);
  color: var(--text);
}
.logo-brand-name .brand-suffix {
  margin-left: 0.2rem;
  font-weight: 500;
  font-size: 1rem;
  color: var(--text-body);
}

.logo-subtext {
  font-size: 11px;
  color: var(--text-muted);
  letter-spacing: 0.05em;
  line-height: 1;
  margin-top: 1px;
}

/* Desktop Nav Menu */
.nav-menu {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  list-style: none;
}

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

.nav-link:hover, .nav-link.active {
  color: var(--cyan-dark);
}

.nav-link.active::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 20px;
  height: 2px;
  background-color: var(--cyan-dark);
}

.header-cta {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  padding: 0.5rem 1.125rem;
  border: 1px solid var(--cyan-dark);
  color: var(--cyan-dark);
  font-weight: 600;
  font-size: 0.9375rem;
  transition: all 0.2s ease;
}

.header-cta:hover {
  background-color: var(--cyan-dark);
  color: var(--bg-white);
  text-decoration: none;
}

/* Mobile Nav Toggle */
.mobile-menu-btn {
  display: none;
  font-size: 1.25rem;
  color: var(--text);
  padding: 0.5rem;
}

/* ==================================================
   Hero Section - Typography Scale System
   ================================================== */
.hero-section {
  padding: 4rem 0 3rem;
  position: relative;
  background-color: var(--bg);
  border-bottom: 1px solid var(--border);
  overflow: hidden;
}

.hero-typography-grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 1.5rem;
  align-items: start;
  margin-bottom: 3rem;
  position: relative;
}

/* Giant Characters "青", "云", "梯" with staggered baselines & numbers */
.hero-typo-item {
  display: flex;
  flex-direction: column;
}

.hero-typo-item.item-1 {
  grid-column: 1 / span 4;
}

.hero-typo-item.item-2 {
  grid-column: 5 / span 4;
  margin-top: 1.5rem; /* Staggered height */
  margin-left: 1rem;
}

.hero-typo-item.item-3 {
  grid-column: 9 / span 4;
  margin-top: -0.5rem; /* Staggered height */
  margin-left: 2rem;
}

.typo-number {
  font-size: 0.875rem;
  color: var(--warm-brown);
  font-weight: 600;
  letter-spacing: 0.1em;
  margin-bottom: 0.25rem;
}

.typo-char {
  font-size: clamp(64px, 9vw, 120px);
  font-weight: 800;
  line-height: 0.95;
  letter-spacing: -0.03em;
  color: var(--cyan-dark);
}

.hero-typo-item.item-2 .typo-char {
  color: var(--green-cyan);
}

.hero-typo-item.item-3 .typo-char {
  color: var(--text);
}

/* Hero Content Block */
.hero-content {
  max-width: 820px;
  margin-top: 1.5rem;
}

.hero-brand-tag {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--cyan-dark);
  margin-bottom: 0.5rem;
  letter-spacing: 0.02em;
}

.hero-lead-text {
  font-size: clamp(1.375rem, 2.5vw, 1.875rem);
  font-weight: 700;
  color: var(--text);
  line-height: 1.4;
  margin-bottom: 1.25rem;
  letter-spacing: -0.01em;
}

.hero-h1 {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--text-body);
  margin-bottom: 1.25rem;
  line-height: 1.5;
}

.hero-description {
  font-size: 1.0625rem;
  color: var(--text-body);
  margin-bottom: 2rem;
  max-width: 760px;
}

.hero-cta-group {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 1.5rem;
  margin-bottom: 3rem;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.875rem 2rem;
  background-color: var(--cyan-dark);
  color: var(--bg-white);
  font-size: 1.0625rem;
  font-weight: 600;
  border-radius: 0;
  transition: background-color 0.2s ease, transform 0.1s ease;
}

.btn-primary:hover {
  background-color: var(--cyan-dark2);
  color: var(--bg-white);
  text-decoration: none;
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.875rem 1.75rem;
  border: 1px solid var(--border);
  background-color: var(--bg-white);
  color: var(--text);
  font-size: 1.0625rem;
  font-weight: 600;
  transition: border-color 0.2s ease, color 0.2s ease;
}

.btn-secondary:hover {
  border-color: var(--cyan-dark);
  color: var(--cyan-dark);
  text-decoration: none;
}

.link-text {
  font-size: 1rem;
  font-weight: 600;
  color: var(--cyan-dark);
}

/* Hero Bottom Navigation Bar */
.hero-nav-bar {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.75rem 1.25rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  font-size: 0.9375rem;
}

.hero-nav-item {
  color: var(--text-body);
  font-weight: 500;
}

.hero-nav-item:hover {
  color: var(--cyan-dark);
}

.hero-nav-sep {
  color: var(--border);
  font-size: 0.875rem;
}

/* ==================================================
   Section Typography Layouts ("字阶" System)
   ================================================== */
.section-block {
  padding: 4.5rem 0;
  border-bottom: 1px solid var(--border);
  position: relative;
}

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

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

.section-number {
  font-size: 0.9375rem;
  font-weight: 700;
  color: var(--warm-brown);
  letter-spacing: 0.15em;
  margin-bottom: 0.25rem;
  display: block;
}

.section-title {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--cyan-dark);
  letter-spacing: 0.05em;
  text-transform: uppercase;
  margin-bottom: 0.5rem;
}

.section-h2 {
  font-size: clamp(24px, 3.2vw, 36px);
  color: var(--text);
  max-width: 900px;
}

/* Background Giant Watermark Letter (aria-hidden="true") */
.giant-bg-char {
  position: absolute;
  top: -2rem;
  font-size: clamp(100px, 16vw, 180px);
  font-weight: 900;
  color: var(--bg-giant-text);
  line-height: 1;
  user-select: none;
  pointer-events: none;
  z-index: 0;
}

/* Variant Positions for Giant Watermark Characters */
.char-pos-left { left: 0; }
.char-pos-right { right: 2rem; }
.char-pos-center { left: 50%; transform: translateX(-50%); }
.char-pos-top { top: -3rem; left: 10%; }
.char-pos-bottom { bottom: 0; right: 5%; }

/* Content Grid / Staggered Baseline Layouts */
.typo-stagger-list {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 1.5rem;
  position: relative;
  z-index: 1;
}

/* 01 Package Selector Section */
.plan-stagger-item {
  padding-top: 1rem;
}

.plan-stagger-item.p1 { grid-column: 1 / span 6; margin-inline-start: 0; }
.plan-stagger-item.p2 { grid-column: 7 / span 6; margin-inline-start: 2rem; }
.plan-stagger-item.p3 { grid-column: 1 / span 6; margin-inline-start: 0; }
.plan-stagger-item.p4 { grid-column: 7 / span 6; margin-inline-start: 3rem; }

.plan-number-gb {
  font-size: clamp(36px, 4.5vw, 54px);
  font-weight: 800;
  color: var(--cyan-dark);
  line-height: 1;
  margin-bottom: 0.5rem;
}

.plan-tag {
  display: inline-block;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--warm-brown);
  margin-bottom: 0.5rem;
}

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

/* 02 Region Nodes Section */
.node-typo-row {
  margin-bottom: 2rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--border);
}

.node-typo-row.n-hk { margin-inline-start: 0; }
.node-typo-row.n-jp { margin-inline-start: 3rem; }
.node-typo-row.n-sg { margin-inline-start: 1rem; }
.node-typo-row.n-us { margin-inline-start: 5rem; }

.node-region-title {
  font-size: clamp(28px, 4vw, 42px);
  font-weight: 800;
  color: var(--text);
  margin-bottom: 0.5rem;
}

/* 03 Line Knowledge Section */
.line-typo-grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 1.5rem;
  margin-bottom: 2.5rem;
}

.line-item {
  padding-top: 1rem;
}

.line-item.l-direct { grid-column: 1 / span 6; margin-inline-start: 0; }
.line-item.l-relay { grid-column: 7 / span 6; margin-inline-start: 2rem; }
.line-item.l-iepl { grid-column: 1 / span 6; margin-inline-start: 0; }
.line-item.l-iplc { grid-column: 7 / span 6; margin-inline-start: 4rem; }

.line-name {
  font-size: clamp(28px, 3.5vw, 40px);
  font-weight: 800;
  color: var(--cyan-dark);
  margin-bottom: 0.5rem;
}

/* Line Comparison HTML Table */
.table-wrapper {
  width: 100%;
  overflow-x: auto;
  margin-top: 2rem;
}

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

.line-table th {
  padding: 1rem;
  font-weight: 700;
  color: var(--text);
  border-bottom: 2px solid var(--cyan-dark);
  background-color: transparent;
}

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

.line-table tr:hover td {
  background-color: rgba(64, 93, 102, 0.03);
}

/* 04 AI Tools Section */
.ai-typo-layout {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 1.5rem;
}

.ai-primary-item {
  margin-bottom: 1.5rem;
}

.ai-item-chatgpt { grid-column: 1 / span 4; margin-inline-start: 0; }
.ai-item-claude { grid-column: 5 / span 4; margin-inline-start: 1.5rem; }
.ai-item-gemini { grid-column: 9 / span 4; margin-inline-start: 3rem; }

.ai-primary-name {
  font-size: clamp(26px, 3.2vw, 38px);
  font-weight: 800;
  color: var(--text);
  margin-bottom: 0.5rem;
}

.ai-secondary-wrap {
  grid-column: 1 / span 12;
  margin-top: 1.5rem;
  padding-top: 1.5rem;
  border-top: 1px dashed var(--border);
  display: flex;
  flex-wrap: wrap;
  gap: 2rem;
}

.ai-secondary-item {
  flex: 1 1 250px;
}

.ai-secondary-name {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--cyan-dark);
  margin-bottom: 0.25rem;
}

/* 05 Streaming Section */
.stream-typo-layout {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

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

.stream-item.st-yt { margin-inline-start: 0; }
.stream-item.st-nf { margin-inline-start: 3.5rem; }
.stream-item.st-dp { margin-inline-start: 1rem; }

.stream-name {
  font-size: clamp(26px, 3.5vw, 38px);
  font-weight: 800;
  color: var(--cyan-dark);
  margin-bottom: 0.5rem;
}

.stream-aux-row {
  display: flex;
  gap: 3rem;
  margin-top: 1rem;
}

.stream-aux-name {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text);
}

/* 06 Clients Section */
.client-device-grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 1.5rem;
}

.client-item.c-win { grid-column: 1 / span 6; margin-inline-start: 0; }
.client-item.c-mac { grid-column: 7 / span 6; margin-inline-start: 2rem; }
.client-item.c-and { grid-column: 1 / span 6; margin-inline-start: 1rem; }
.client-item.c-ios { grid-column: 7 / span 6; margin-inline-start: 3rem; }

.client-device-name {
  font-size: clamp(26px, 3.5vw, 38px);
  font-weight: 800;
  color: var(--text);
  margin-bottom: 0.5rem;
}

.client-topics-index {
  grid-column: 1 / span 12;
  margin-top: 2rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  display: flex;
  flex-wrap: wrap;
  gap: 1rem 2rem;
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--cyan-dark);
}

/* 07 Full Pricing List Section (No pricing cards!) */
.pricing-list-wrap {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  margin-top: 2rem;
}

.price-row-item {
  padding: 1.5rem 0;
  border-bottom: 1px solid var(--border);
  display: grid;
  grid-template-columns: 60px 140px 140px 140px 1fr auto;
  align-items: center;
  gap: 1rem;
}

.price-row-item.p-row-1 { margin-inline-start: 0; }
.price-row-item.p-row-2 { margin-inline-start: 1.5rem; }
.price-row-item.p-row-3 { 
  margin-inline-start: 0; 
  background-color: var(--light-green); /* Highlighted plan */
  padding: 1.5rem 1rem;
  border-left: 3px solid var(--green-cyan);
}
.price-row-item.p-row-4 { margin-inline-start: 2.5rem; }
.price-row-item.p-row-5 { margin-inline-start: 0; }

.price-num {
  font-size: 1rem;
  font-weight: 700;
  color: var(--warm-brown);
}

.price-name {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text);
}

.price-gb {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--cyan-dark);
}

.price-val {
  font-size: 1.75rem;
  font-weight: 800;
  color: var(--text);
}

.price-row-item.p-row-3 .price-val {
  font-size: 2.25rem;
  color: var(--green-dark);
}

.price-usage {
  font-size: 0.9375rem;
  color: var(--text-body);
}

.price-badge-featured {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  background-color: var(--green-cyan);
  color: var(--bg-white);
  padding: 0.15rem 0.5rem;
  margin-left: 0.5rem;
}

/* 08 Deep Review Section */
.review-section-wrap {
  display: flex;
  gap: 3rem;
  align-items: start;
}

.review-giant-letter {
  font-size: clamp(100px, 15vw, 180px);
  font-weight: 900;
  color: var(--cyan-dark);
  line-height: 0.9;
  flex-shrink: 0;
}

.review-content-body {
  flex: 1;
}

/* 09 Articles Directory Section */
.articles-list-stagger {
  display: flex;
  flex-direction: column;
  gap: 1.75rem;
}

.article-list-item {
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--border);
  display: flex;
  flex-direction: column;
}

.article-list-item.a-item-1 { margin-inline-start: 0; }
.article-list-item.a-item-2 { margin-inline-start: 2rem; }
.article-list-item.a-item-3 { margin-inline-start: 0; }
.article-list-item.a-item-4 { margin-inline-start: 3rem; }

.article-meta-line {
  display: flex;
  align-items: center;
  gap: 1rem;
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-bottom: 0.4rem;
}

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

.article-cat-tag {
  color: var(--cyan-dark);
  font-weight: 600;
}

.article-item-title {
  font-size: clamp(1.25rem, 2.2vw, 1.625rem);
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.article-item-title.featured-title {
  font-size: clamp(1.5rem, 2.8vw, 2rem);
  color: var(--cyan-dark);
}

.article-item-excerpt {
  font-size: 1rem;
  color: var(--text-body);
  margin-bottom: 0.75rem;
}

/* 10 Troubleshooting Section */
.trouble-stagger-list {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.trouble-item {
  padding-bottom: 1.25rem;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: baseline;
  gap: 1.5rem;
}

.trouble-item.t1 { margin-inline-start: 0; }
.trouble-item.t2 { margin-inline-start: 1.5rem; }
.trouble-item.t3 { margin-inline-start: 3rem; }
.trouble-item.t4 { margin-inline-start: 0; }
.trouble-item.t5 { margin-inline-start: 2rem; }
.trouble-item.t6 { margin-inline-start: 4rem; }
.trouble-item.t7 { margin-inline-start: 0; }

.trouble-num {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--warm-brown);
  flex-shrink: 0;
}

.trouble-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 0.25rem;
}

/* 11 FAQ Section (Text-based Accordion) */
.faq-list-wrap {
  display: flex;
  flex-direction: column;
}

.faq-group-title {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--cyan-dark);
  margin: 2rem 0 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--cyan-dark);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

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

.faq-button {
  width: 100%;
  padding: 1.25rem 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  text-align: left;
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--text);
  transition: color 0.2s ease;
}

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

.faq-q-code {
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--warm-brown);
  margin-right: 0.75rem;
}

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

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

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease, padding 0.3s ease;
  background-color: var(--light-warm);
}

.faq-answer-inner {
  padding: 1rem 1.5rem 1.5rem;
  font-size: 1rem;
  color: var(--text-body);
  line-height: 1.8;
}

.faq-item.is-open .faq-answer {
  max-height: 500px;
}

/* ==================================================
   Article Template Styles
   ================================================== */
.article-header {
  padding: 3rem 0 2rem;
  border-bottom: 1px solid var(--border);
  position: relative;
}

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

.article-hero-wrap {
  display: flex;
  gap: 2rem;
  align-items: flex-start;
}

.article-cat-letter {
  font-size: 80px;
  font-weight: 900;
  color: var(--cyan-dark);
  line-height: 0.85;
  user-select: none;
  flex-shrink: 0;
}

.article-header-main {
  flex: 1;
}

.article-meta-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-top: 1rem;
}

/* Quick Answer / GEO Box */
.quick-conclusion-box {
  margin: 2rem 0;
  padding: 1.5rem;
  background-color: var(--light-warm);
  border-left: 3px solid var(--warm-brown);
}

.quick-conclusion-title {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--terracotta);
  margin-bottom: 0.5rem;
}

.quick-conclusion-text {
  font-size: 1.0625rem;
  color: var(--text);
  line-height: 1.8;
  margin-bottom: 0;
}

/* Table of Contents sidebar & Inline */
.article-body-wrapper {
  display: grid;
  grid-template-columns: 1fr 240px;
  gap: 3rem;
  margin: 3rem 0;
}

.article-content {
  min-width: 0;
}

.article-sidebar {
  position: sticky;
  top: 90px;
  height: fit-content;
}

.toc-box {
  padding: 1.25rem;
  border-left: 2px solid var(--border);
  font-size: 0.875rem;
}

.toc-title {
  font-size: 0.9375rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 0.75rem;
}

.toc-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

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

.toc-link:hover, .toc-link.active {
  color: var(--cyan-dark);
  font-weight: 600;
}

/* Related Content Links */
.related-articles-box {
  margin: 3rem 0;
  padding: 1.75rem;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  background-color: var(--bg-subtle);
}

.related-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--cyan-dark);
  margin-bottom: 1rem;
}

.related-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.related-link {
  font-weight: 600;
}

/* Category Page Hero */
.category-hero {
  padding: 3rem 0 2rem;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: baseline;
  gap: 2rem;
}

.category-giant-letter {
  font-size: 90px;
  font-weight: 900;
  color: var(--cyan-dark);
  line-height: 0.9;
  flex-shrink: 0;
}

/* ==================================================
   Footer (Compact & Lightweight)
   ================================================== */
.site-footer {
  background-color: var(--bg-subtle);
  border-top: 1px solid var(--border);
  padding: 3rem 0 1.5rem;
  margin-top: auto;
  color: var(--text-body);
  font-size: 0.9375rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr 1fr;
  gap: 2rem;
  margin-bottom: 2.5rem;
}

.footer-brand-title {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--text);
  margin-bottom: 0.5rem;
}

.footer-brand-desc {
  font-size: 0.875rem;
  color: var(--text-muted);
  max-width: 280px;
  margin-bottom: 1rem;
}

.footer-col-title {
  font-size: 0.9375rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 1rem;
  letter-spacing: 0.05em;
}

.footer-link-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  font-size: 0.875rem;
}

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

.footer-link-list a:hover {
  color: var(--cyan-dark);
}

.footer-bottom {
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  font-size: 0.875rem;
  color: var(--text-muted);
}

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

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

/* ==================================================
   Responsive Media Queries (375, 390, 430, 768, 1024, 1440)
   ================================================== */
@media (max-width: 1024px) {
  .hero-typography-grid {
    gap: 1rem;
  }
  .article-body-wrapper {
    grid-template-columns: 1fr;
  }
  .article-sidebar {
    display: none; /* Collapsed TOC on tablet */
  }
  .price-row-item {
    grid-template-columns: 40px 100px 100px 120px 1fr auto;
  }
  .footer-grid {
    grid-template-columns: 1.5fr 1fr 1fr 1fr;
  }
}

@media (max-width: 768px) {
  /* Mobile resets for baseline shifts to preserve mobile readability */
  .hero-typo-item.item-1,
  .hero-typo-item.item-2,
  .hero-typo-item.item-3,
  .plan-stagger-item.p1,
  .plan-stagger-item.p2,
  .plan-stagger-item.p3,
  .plan-stagger-item.p4,
  .node-typo-row.n-hk,
  .node-typo-row.n-jp,
  .node-typo-row.n-sg,
  .node-typo-row.n-us,
  .line-item.l-direct,
  .line-item.l-relay,
  .line-item.l-iepl,
  .line-item.l-iplc,
  .ai-item-chatgpt,
  .ai-item-claude,
  .ai-item-gemini,
  .stream-item.st-yt,
  .stream-item.st-nf,
  .stream-item.st-dp,
  .client-item.c-win,
  .client-item.c-mac,
  .client-item.c-and,
  .client-item.c-ios,
  .price-row-item.p-row-1,
  .price-row-item.p-row-2,
  .price-row-item.p-row-3,
  .price-row-item.p-row-4,
  .price-row-item.p-row-5,
  .article-list-item.a-item-1,
  .article-list-item.a-item-2,
  .article-list-item.a-item-3,
  .article-list-item.a-item-4,
  .trouble-item.t1,
  .trouble-item.t2,
  .trouble-item.t3,
  .trouble-item.t4,
  .trouble-item.t5,
  .trouble-item.t6,
  .trouble-item.t7 {
    margin-inline-start: 0 !important;
    grid-column: 1 / span 12 !important;
  }

  .nav-menu {
    display: none;
    position: absolute;
    top: 70px;
    left: 0;
    width: 100%;
    background-color: var(--bg);
    border-bottom: 1px solid var(--border);
    flex-direction: column;
    padding: 1.5rem;
    gap: 1rem;
    box-shadow: 0 10px 20px rgba(0,0,0,0.05);
  }

  .nav-menu.is-active {
    display: flex;
  }

  .mobile-menu-btn {
    display: block;
  }

  .hero-typography-grid {
    display: flex;
    justify-content: flex-start;
    gap: 1rem;
    margin-bottom: 1.5rem;
  }

  .typo-char {
    font-size: clamp(48px, 14vw, 72px);
  }

  .price-row-item {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 0.5rem;
    padding: 1.25rem 0;
  }

  .review-section-wrap {
    flex-direction: column;
    gap: 1rem;
  }

  .review-giant-letter {
    font-size: 80px;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

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

/* Prefers Reduced Motion Rule */
@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;
  }
}