/* ===================================================================
   木瓜云 (muguacloud.mom) - 瑞士理性主义高对比网格样式表
   Swiss Rationalist High-Contrast Typographic System
   100% Flat & Shadowless | 1px Rigid Hairlines | 0ms Optical Inversions
=================================================================== */

:root {
  /* 基础设计参数 */
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  --font-display: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;

  /* 默认白天模式 (Light Mode) - 极具包豪斯与瑞士出版物风格的高对比纸墨质感 */
  --bg-pitch: #ffffff;
  --bg-surface: #f4f4f5;
  --bg-surface-hover: #e4e4e7;
  --bg-badge: #18181b;

  --border-rigid: #18181b;
  --border-subtle: #e4e4e7;
  --border-hairline: 1px solid #18181b;
  --border-hairline-subtle: 1px solid #e4e4e7;

  --text-main: #09090b;
  --text-sub: #3f3f46;
  --text-muted: #71717a;
  --text-inv: #ffffff;

  /* 核心撞色警示色盘 (Assertive Warning Palette) */
  --cobalt-blue: #1d4ed8;
  --cobalt-blue-hover: #1e40af;
  --alert-purple: #7c3aed;
  --alert-purple-hover: #6d28d9;
  --accent-orange: #ff6b35;

  /* 阴影完全归零 (Entirely shadowless & flat) */
  --box-shadow-none: none;
}

/* 黑夜模式 (Dark Mode) - 深度曜石纯黑 + 高压激光蓝 + 电感警戒紫 */
[data-theme="dark"] {
  --bg-pitch: #08080a;
  --bg-surface: #101014;
  --bg-surface-hover: #18181f;
  --bg-badge: #ffffff;

  --border-rigid: #27272a;
  --border-subtle: #18181b;
  --border-hairline: 1px solid #27272a;
  --border-hairline-subtle: 1px solid #18181b;

  --text-main: #ffffff;
  --text-sub: #a1a1aa;
  --text-muted: #71717a;
  --text-inv: #08080a;

  --cobalt-blue: #2563eb;
  --cobalt-blue-hover: #3b82f6;
  --alert-purple: #8b5cf6;
  --alert-purple-hover: #a78bfa;
  --accent-orange: #ff7847;
}

/* 全局重置与排版规范 */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  border-radius: 0 !important; /* 彻底移除圆角，贯彻瑞士理性主义矩形网格 */
}

html {
  font-family: var(--font-display);
  scroll-behavior: smooth;
  font-size: 16px;
  line-height: 1.5;
  background-color: var(--bg-pitch);
  color: var(--text-main);
  -webkit-font-smoothing: antialiased;
}

body {
  background-color: var(--bg-pitch);
  color: var(--text-main);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  box-shadow: none !important;
}

/* 平滑锚点过渡偏移量保护（针对固定头部） */
:target {
  scroll-margin-top: 80px;
}

/* 容器定义 - 刚性网格 */
.container {
  width: 100%;
  max-width: 1240px;
  margin-left: auto;
  margin-right: auto;
  padding-left: 24px;
  padding-right: 24px;
}

/* 顶部严谨导航栏 (Rigid Swiss Nav) */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: var(--bg-pitch);
  border-bottom: 2px solid var(--border-rigid);
  transition: background-color 0.2s ease, border-color 0.2s ease;
}

.nav-wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}

/* Logo 刚性排版 */
.site-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--text-main);
  font-weight: 900;
  font-size: 1.25rem;
  letter-spacing: -0.5px;
  text-transform: uppercase;
}

.logo-badge {
  width: 34px;
  height: 34px;
  background: var(--cobalt-blue);
  color: #ffffff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-weight: 900;
  font-size: 1.15rem;
  border: 1px solid var(--border-rigid);
  flex-shrink: 0;
}

.logo-text-wrap {
  display: inline-flex;
  align-items: baseline;
  gap: 2px;
}

.logo-brand-name {
  font-weight: 900;
  letter-spacing: -0.5px;
}

.logo-brand-sub {
  font-size: 0.8rem;
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--alert-purple);
  margin-left: 4px;
}

/* 导航栏链接项 */
.site-nav {
  display: flex;
  align-items: center;
  gap: 0;
  height: 100%;
}

.nav-link {
  color: var(--text-sub);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 700;
  padding: 0 16px;
  height: 68px;
  display: inline-flex;
  align-items: center;
  border-left: 1px solid var(--border-subtle);
  transition: background-color 0s, color 0s; /* 0ms 瞬间光学反转响应 */
  position: relative;
}

.nav-link:last-child {
  border-right: 1px solid var(--border-subtle);
}

.nav-link:hover, .nav-link:focus {
  background-color: var(--cobalt-blue);
  color: #ffffff;
}

/* 推荐资讯重点高光标识 */
.nav-link.nav-highlight {
  color: var(--alert-purple);
  position: relative;
}

.nav-link.nav-highlight::after {
  content: "NEW";
  font-family: var(--font-mono);
  font-size: 0.65rem;
  background: var(--alert-purple);
  color: #ffffff;
  padding: 1px 4px;
  margin-left: 6px;
  line-height: 1;
}

.nav-link.nav-highlight:hover {
  background-color: var(--alert-purple);
  color: #ffffff;
}

.nav-link.nav-highlight:hover::after {
  background: #ffffff;
  color: var(--alert-purple);
}

/* 导航右侧操作区 */
.nav-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

/* 精致专业昼夜模式切换按钮 (Swiss Hairline Toggle) */
.theme-toggle-btn {
  background: transparent;
  border: 1px solid var(--border-rigid);
  color: var(--text-main);
  height: 38px;
  padding: 0 14px;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 700;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
  transition: background-color 0s, color 0s;
  text-transform: uppercase;
}

.theme-toggle-btn:hover {
  background: var(--border-rigid);
  color: var(--text-inv);
}

.theme-toggle-btn svg {
  width: 14px;
  height: 14px;
  fill: none;
  stroke: currentColor;
  stroke-width: 2.2;
}

[data-theme="light"] .theme-toggle-btn .moon-icon { display: block; }
[data-theme="light"] .theme-toggle-btn .sun-icon { display: none; }
[data-theme="dark"] .theme-toggle-btn .moon-icon { display: none; }
[data-theme="dark"] .theme-toggle-btn .sun-icon { display: block; }

/* 刚性按钮系统 (Rigid Mathematical Action Buttons) */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  height: 44px;
  padding: 0 24px;
  font-size: 0.92rem;
  font-weight: 800;
  text-decoration: none;
  cursor: pointer;
  border: 1px solid var(--border-rigid);
  text-transform: uppercase;
  letter-spacing: 0.3px;
  box-shadow: none !important;
  transition: background-color 0s, color 0s, transform 0.08s ease; /* 瞬间响应 */
  white-space: nowrap;
}

.btn:active {
  transform: translate(2px, 2px);
}

.btn-primary {
  background: var(--cobalt-blue);
  color: #ffffff;
  border-color: var(--cobalt-blue);
}

.btn-primary:hover {
  background: #ffffff;
  color: var(--cobalt-blue);
  border-color: var(--cobalt-blue);
}

.btn-alert {
  background: var(--alert-purple);
  color: #ffffff;
  border-color: var(--alert-purple);
}

.btn-alert:hover {
  background: #ffffff;
  color: var(--alert-purple);
}

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

.btn-secondary:hover {
  background: var(--border-rigid);
  color: var(--text-inv);
}

.btn-lg {
  height: 52px;
  padding: 0 32px;
  font-size: 1.05rem;
}

.btn-block {
  width: 100%;
}

/* ===================================================================
   主视觉区 (Swiss Warning Poster Hero Section)
=================================================================== */
.hero-section {
  position: relative;
  border-bottom: 2px solid var(--border-rigid);
  padding: 64px 0 54px;
  background-color: var(--bg-pitch);
}

/* 顶部状态角标栏 (Top-left warning status bar) */
.hero-top-status {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border: 1px solid var(--border-rigid);
  background: var(--bg-surface);
  padding: 8px 16px;
  margin-bottom: 36px;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-weight: 700;
}

.status-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--cobalt-blue);
}

.status-dot {
  width: 8px;
  height: 8px;
  background: #10b981;
  display: inline-block;
  animation: pulse-dot 2s infinite ease-in-out;
}

@keyframes pulse-dot {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.3; }
}

.status-info {
  color: var(--text-muted);
}

/* 巨幅12度前倾斜体无衬线大标题 (12deg Leaning Massive Grotesk Headline) */
.hero-headline-block {
  margin-bottom: 32px;
}

.hero-brand-tag {
  font-family: var(--font-mono);
  font-size: 0.88rem;
  font-weight: 800;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--cobalt-blue);
  margin-bottom: 12px;
  display: block;
}

.hero-title {
  font-size: clamp(2.4rem, 5.5vw, 4.4rem);
  font-weight: 900;
  line-height: 1.08;
  letter-spacing: -2px;
  text-transform: uppercase;
  color: var(--text-main);
  /* 核心指定：Massive italic grotesk leaning forward at 12 degrees */
  font-style: italic;
  transform: skewX(-12deg);
  transform-origin: left bottom;
  display: inline-block;
  margin-bottom: 24px;
}

.hero-title .brand-highlight {
  background: var(--cobalt-blue);
  color: #ffffff;
  padding: 2px 14px;
  margin-right: 6px;
  font-style: normal;
  display: inline-block;
}

.hero-title .purple-highlight {
  color: var(--alert-purple);
}

/* 主视觉简介 (Detailed intro paragraph) */
.hero-intro-box {
  max-width: 840px;
  border-left: 4px solid var(--cobalt-blue);
  padding: 12px 0 12px 20px;
  margin-bottom: 40px;
}

.hero-subtitle {
  font-size: 1.28rem;
  font-weight: 700;
  color: var(--text-main);
  line-height: 1.45;
  margin-bottom: 10px;
}

.hero-desc {
  font-size: 1rem;
  color: var(--text-sub);
  line-height: 1.7;
}

.hero-actions {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 48px;
  flex-wrap: wrap;
}

/* 刚性实心蓝紫矩形数据块 (Bold Solid Blue-Violet Rectangular Blocks) */
.bandwidth-stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  border: 1px solid var(--border-rigid);
  background: var(--border-rigid);
  gap: 1px;
}

.stat-box {
  background: var(--bg-surface);
  padding: 24px 20px;
  display: flex;
  flex-direction: column;
  transition: background-color 0s, color 0s; /* 0ms 瞬间反转 */
}

.stat-box:hover {
  background: var(--cobalt-blue);
  color: #ffffff;
}

.stat-box:hover .stat-label,
.stat-box:hover .stat-code {
  color: #ffffff;
  opacity: 0.9;
}

.stat-code {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--text-muted);
  margin-bottom: 6px;
}

.stat-value {
  font-size: 2.1rem;
  font-weight: 900;
  font-family: var(--font-mono);
  line-height: 1.1;
  color: var(--text-main);
  margin-bottom: 4px;
}

.stat-box:hover .stat-value {
  color: #ffffff;
}

.stat-label {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--text-sub);
}

/* 底部极简垂直药丸滚动指示标 (Minimalist Vertical Pill Scroll Indicator) */
.scroll-indicator-wrap {
  display: flex;
  justify-content: center;
  align-items: center;
  padding-top: 36px;
}

.scroll-pill {
  width: 24px;
  height: 42px;
  border: 2px solid var(--border-rigid);
  display: flex;
  justify-content: center;
  padding-top: 6px;
}

.scroll-pill-inner {
  width: 4px;
  height: 10px;
  background: var(--cobalt-blue);
  animation: scroll-drop 1.6s infinite ease-in-out;
}

@keyframes scroll-drop {
  0% { transform: translateY(0); opacity: 1; }
  100% { transform: translateY(18px); opacity: 0; }
}

/* ===================================================================
   板块通用架构 (Sections Layout with 1px Rigid Hairlines)
=================================================================== */
.section {
  padding: 72px 0;
  border-bottom: 2px solid var(--border-rigid);
}

.section-header-poster {
  border-bottom: 1px solid var(--border-rigid);
  padding-bottom: 24px;
  margin-bottom: 44px;
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  flex-wrap: wrap;
  gap: 16px;
}

.section-number {
  font-family: var(--font-mono);
  font-size: 0.88rem;
  font-weight: 800;
  color: var(--cobalt-blue);
  margin-bottom: 6px;
}

.section-title {
  font-size: 2.2rem;
  font-weight: 900;
  letter-spacing: -1px;
  text-transform: uppercase;
}

.section-tagline {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--text-muted);
  max-width: 420px;
  text-align: right;
}

/* ===================================================================
   核心优势介绍 (3个图文卡片 - 0ms光学反转微交互)
=================================================================== */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border: 1px solid var(--border-rigid);
  background: var(--border-rigid);
  gap: 1px;
}

.feature-poster-card {
  background: var(--bg-pitch);
  padding: 36px 30px;
  display: flex;
  flex-direction: column;
  transition: background-color 0s, color 0s; /* 0ms 瞬间光学反转 */
}

/* 核心指定交互：0ms optical inversion into solid high-voltage cobalt blue & purple */
.feature-poster-card:hover {
  background: var(--cobalt-blue);
  color: #ffffff;
}

.feature-poster-card:nth-child(2):hover {
  background: var(--alert-purple);
}

.feature-num {
  font-family: var(--font-mono);
  font-size: 2.4rem;
  font-weight: 900;
  color: var(--cobalt-blue);
  line-height: 1;
  margin-bottom: 18px;
  border-bottom: 2px solid var(--border-rigid);
  padding-bottom: 12px;
}

.feature-poster-card:hover .feature-num {
  color: #ffffff;
  border-color: #ffffff;
}

.feature-title {
  font-size: 1.35rem;
  font-weight: 900;
  margin-bottom: 14px;
  letter-spacing: -0.5px;
}

.feature-body {
  font-size: 0.95rem;
  color: var(--text-sub);
  line-height: 1.7;
}

.feature-poster-card:hover .feature-body {
  color: #ffffff;
}

/* ===================================================================
   流媒体图卡 & AI 支持图卡展示区
=================================================================== */
.specialty-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  border: 1px solid var(--border-rigid);
  background: var(--border-rigid);
  gap: 1px;
}

.specialty-block {
  background: var(--bg-pitch);
  padding: 40px 32px;
  display: flex;
  flex-direction: column;
}

.specialty-header-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 2px solid var(--border-rigid);
  padding-bottom: 16px;
  margin-bottom: 24px;
}

.specialty-badge-rigid {
  background: var(--cobalt-blue);
  color: #ffffff;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 800;
  padding: 4px 10px;
  text-transform: uppercase;
}

.specialty-badge-rigid.purple {
  background: var(--alert-purple);
}

.specialty-title {
  font-size: 1.6rem;
  font-weight: 900;
  margin-bottom: 12px;
  letter-spacing: -0.5px;
}

.specialty-summary {
  font-size: 0.95rem;
  color: var(--text-sub);
  line-height: 1.65;
  margin-bottom: 28px;
}

/* 表格化刚性标签网格 */
.spec-app-table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 24px;
  font-family: var(--font-mono);
}

.spec-app-table td {
  border: 1px solid var(--border-subtle);
  padding: 12px 14px;
  font-size: 0.85rem;
  font-weight: 700;
  transition: background-color 0s, color 0s;
}

.spec-app-table tr:hover td {
  background: var(--cobalt-blue);
  color: #ffffff;
}

.spec-node-latency {
  text-align: right;
  color: #10b981;
}

.spec-app-table tr:hover .spec-node-latency {
  color: #ffffff;
}

.spec-checklist {
  list-style: none;
  border-top: 1px solid var(--border-rigid);
  padding-top: 20px;
  margin-top: auto;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.spec-checklist li {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.9rem;
  color: var(--text-sub);
}

.spec-checklist li::before {
  content: "■";
  color: var(--cobalt-blue);
  font-size: 0.8rem;
}

/* ===================================================================
   清晰的套餐价格对比表 (参考网上真实套餐价格)
=================================================================== */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border: 1px solid var(--border-rigid);
  background: var(--border-rigid);
  gap: 1px;
}

.pricing-box {
  background: var(--bg-pitch);
  padding: 40px 32px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: background-color 0s, color 0s;
}

.pricing-box.featured {
  background: var(--bg-surface);
  outline: 3px solid var(--cobalt-blue);
  outline-offset: -3px;
  z-index: 2;
}

.pricing-flag {
  position: absolute;
  top: 0;
  right: 0;
  background: var(--cobalt-blue);
  color: #ffffff;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 800;
  padding: 4px 12px;
  text-transform: uppercase;
}

.pricing-plan-name {
  font-size: 1.4rem;
  font-weight: 900;
  margin-bottom: 6px;
  letter-spacing: -0.5px;
}

.pricing-plan-desc {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 24px;
}

.pricing-cost-row {
  border-top: 1px solid var(--border-rigid);
  border-bottom: 1px solid var(--border-rigid);
  padding: 20px 0;
  margin-bottom: 28px;
  display: flex;
  align-items: baseline;
  gap: 4px;
}

.pricing-currency {
  font-size: 1.4rem;
  font-weight: 800;
  font-family: var(--font-mono);
}

.pricing-number {
  font-size: 3.4rem;
  font-weight: 900;
  font-family: var(--font-mono);
  line-height: 1;
  letter-spacing: -2px;
}

.pricing-unit {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text-muted);
  margin-left: 4px;
}

.pricing-spec-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 36px;
  flex-grow: 1;
}

.pricing-spec-list li {
  display: flex;
  justify-content: space-between;
  font-size: 0.9rem;
  border-bottom: 1px dashed var(--border-subtle);
  padding-bottom: 8px;
}

.pricing-spec-list .spec-k {
  color: var(--text-muted);
}

.pricing-spec-list .spec-v {
  font-weight: 800;
  font-family: var(--font-mono);
  color: var(--text-main);
}

/* ===================================================================
   用户评价 (Testimonials - Swiss Publication Cards)
=================================================================== */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border: 1px solid var(--border-rigid);
  background: var(--border-rigid);
  gap: 1px;
}

.review-poster-card {
  background: var(--bg-pitch);
  padding: 32px 28px;
  display: flex;
  flex-direction: column;
  transition: background-color 0s, color 0s;
}

.review-poster-card:hover {
  background: var(--cobalt-blue);
  color: #ffffff;
}

.review-poster-card:hover .review-meta,
.review-poster-card:hover .review-quote {
  color: #ffffff;
}

.review-rating-bar {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 800;
  color: #10b981;
  margin-bottom: 16px;
  letter-spacing: 2px;
}

.review-quote {
  font-size: 0.96rem;
  line-height: 1.7;
  color: var(--text-sub);
  margin-bottom: 24px;
  flex-grow: 1;
}

.review-author-row {
  border-top: 1px solid var(--border-rigid);
  padding-top: 16px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.review-name {
  font-size: 0.92rem;
  font-weight: 800;
}

.review-meta {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text-muted);
}

/* ===================================================================
   常见问题解答 (FAQ - Rigid Accordion with Instant State)
=================================================================== */
.faq-box-wrap {
  border: 1px solid var(--border-rigid);
  background: var(--border-rigid);
  display: flex;
  flex-direction: column;
  gap: 1px;
}

.faq-entry {
  background: var(--bg-pitch);
}

.faq-entry summary {
  padding: 22px 28px;
  cursor: pointer;
  list-style: none;
  font-size: 1.05rem;
  font-weight: 800;
  display: flex;
  justify-content: space-between;
  align-items: center;
  user-select: none;
  transition: background-color 0s, color 0s;
}

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

.faq-entry summary:hover {
  background: var(--cobalt-blue);
  color: #ffffff;
}

.faq-prefix {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--cobalt-blue);
  margin-right: 12px;
}

.faq-entry summary:hover .faq-prefix {
  color: #ffffff;
}

.faq-plus {
  font-family: var(--font-mono);
  font-size: 1.3rem;
  font-weight: 900;
  transition: transform 0.15s ease;
}

.faq-entry[open] summary .faq-plus {
  transform: rotate(45deg);
}

.faq-content-inner {
  padding: 0 28px 24px 28px;
  border-top: 1px dashed var(--border-subtle);
  padding-top: 16px;
  color: var(--text-sub);
  line-height: 1.8;
  font-size: 0.95rem;
}

/* ===================================================================
   底部行动区 (Bottom Assertive CTA)
=================================================================== */
.poster-cta-box {
  background: var(--cobalt-blue);
  color: #ffffff;
  padding: 64px 40px;
  border: 2px solid var(--border-rigid);
  text-align: center;
  position: relative;
  overflow: hidden;
}

.poster-cta-box h2 {
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 900;
  text-transform: uppercase;
  letter-spacing: -1px;
  margin-bottom: 16px;
}

.poster-cta-box p {
  font-size: 1.1rem;
  max-width: 680px;
  margin: 0 auto 36px;
  opacity: 0.95;
  line-height: 1.7;
}

.poster-cta-box .btn-cta-white {
  background: #ffffff;
  color: var(--cobalt-blue);
  font-weight: 900;
  border-color: #ffffff;
}

.poster-cta-box .btn-cta-white:hover {
  background: var(--bg-pitch);
  color: var(--text-main);
  border-color: var(--border-rigid);
}

/* ===================================================================
   页脚 (Footer - 严格只保留4个标题，且新页面打开)
=================================================================== */
.site-footer {
  background-color: var(--bg-pitch);
  border-top: 2px solid var(--border-rigid);
  padding: 48px 0 36px;
  margin-top: auto;
}

.footer-nav {
  display: flex;
  justify-content: center;
  align-items: center;
  border-bottom: 1px solid var(--border-rigid);
  padding-bottom: 32px;
  margin-bottom: 28px;
  flex-wrap: wrap;
}

.footer-link {
  color: var(--text-main);
  text-decoration: none;
  font-size: 1rem;
  font-weight: 800;
  padding: 8px 24px;
  border-right: 1px solid var(--border-subtle);
  transition: background-color 0s, color 0s;
}

.footer-link:first-child {
  border-left: 1px solid var(--border-subtle);
}

.footer-link:hover {
  background: var(--cobalt-blue);
  color: #ffffff;
}

.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-muted);
}

.footer-domain {
  font-weight: 700;
  color: var(--cobalt-blue);
}

/* ===================================================================
   独立子页面通用版式 (关于我们 / 服务条款 / 隐私政策 / 网站地图 / 推荐资讯)
=================================================================== */
.page-container {
  max-width: 1040px;
  margin: 44px auto 80px;
  padding: 0 24px;
}

.page-header-card {
  border: 2px solid var(--border-rigid);
  background: var(--bg-surface);
  padding: 44px 36px;
  margin-bottom: 28px;
}

.page-tag-rigid {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 800;
  color: var(--cobalt-blue);
  margin-bottom: 10px;
  text-transform: uppercase;
}

.page-title {
  font-size: 2.4rem;
  font-weight: 900;
  letter-spacing: -1px;
  text-transform: uppercase;
  margin-bottom: 12px;
}

.page-body-card {
  border: 1px solid var(--border-rigid);
  background: var(--bg-pitch);
  padding: 48px 40px;
}

.page-content-block {
  margin-bottom: 40px;
  border-bottom: 1px dashed var(--border-subtle);
  padding-bottom: 32px;
}

.page-content-block:last-child {
  margin-bottom: 0;
  border-bottom: none;
  padding-bottom: 0;
}

.page-content-block h2 {
  font-size: 1.45rem;
  font-weight: 900;
  margin-bottom: 16px;
  letter-spacing: -0.5px;
  color: var(--text-main);
  display: flex;
  align-items: center;
  gap: 8px;
}

.page-content-block h2::before {
  content: "§";
  color: var(--cobalt-blue);
  font-family: var(--font-mono);
}

.page-content-block p {
  color: var(--text-sub);
  font-size: 0.98rem;
  line-height: 1.8;
  margin-bottom: 16px;
}

.page-content-block ul {
  padding-left: 20px;
  color: var(--text-sub);
  font-size: 0.95rem;
  line-height: 1.8;
  margin-bottom: 16px;
}

.page-content-block li {
  margin-bottom: 10px;
}

.highlight-box-rigid {
  border: 1px solid var(--border-rigid);
  border-left: 6px solid var(--cobalt-blue);
  background: var(--bg-surface);
  padding: 20px 24px;
  margin: 24px 0;
  font-size: 0.95rem;
  line-height: 1.8;
}

.highlight-box-rigid.alert {
  border-left-color: var(--alert-purple);
}

.node-table-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  border: 1px solid var(--border-rigid);
  background: var(--border-rigid);
  gap: 1px;
  margin: 20px 0;
}

.node-item-box {
  background: var(--bg-pitch);
  padding: 16px 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: background-color 0s, color 0s;
}

.node-item-box:hover {
  background: var(--cobalt-blue);
  color: #ffffff;
}

.node-item-box:hover .node-sub {
  color: #ffffff;
  opacity: 0.85;
}

.node-name {
  font-weight: 800;
  font-size: 0.95rem;
}

.node-sub {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* 资讯列表网格 */
.news-cards-list {
  display: flex;
  flex-direction: column;
  border: 1px solid var(--border-rigid);
  background: var(--border-rigid);
  gap: 1px;
}

.news-article-item {
  background: var(--bg-pitch);
  padding: 28px 32px;
  display: flex;
  flex-direction: column;
  transition: background-color 0s, color 0s;
}

.news-article-item:hover {
  background: var(--bg-surface);
}

.news-meta-bar {
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--cobalt-blue);
  margin-bottom: 8px;
}

.news-category-tag {
  background: var(--cobalt-blue);
  color: #ffffff;
  padding: 2px 8px;
}

.news-title {
  font-size: 1.35rem;
  font-weight: 900;
  margin-bottom: 10px;
  letter-spacing: -0.3px;
}

.news-excerpt {
  color: var(--text-sub);
  font-size: 0.95rem;
  line-height: 1.7;
  margin-bottom: 16px;
}

.news-read-more {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-weight: 800;
  font-size: 0.88rem;
  color: var(--cobalt-blue);
  text-decoration: none;
}

.news-read-more:hover {
  text-decoration: underline;
}

/* ===================================================================
   深度科普长文专用排版系统 (Swiss Long-form Prose System)
=================================================================== */
.article-header {
  border: 2px solid var(--border-rigid);
  background: var(--bg-surface);
  padding: 44px 36px 36px;
  margin-bottom: 32px;
}

.article-breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 16px;
  flex-wrap: wrap;
}

.article-breadcrumb a {
  color: var(--text-sub);
  text-decoration: none;
  font-weight: 700;
}

.article-breadcrumb a:hover {
  color: var(--cobalt-blue);
  text-decoration: underline;
}

.article-main-title {
  font-size: clamp(1.8rem, 3.8vw, 2.6rem);
  font-weight: 900;
  line-height: 1.25;
  letter-spacing: -1px;
  margin-bottom: 20px;
  color: var(--text-main);
}

.article-meta-row {
  display: flex;
  align-items: center;
  gap: 16px;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-muted);
  border-top: 1px solid var(--border-subtle);
  padding-top: 16px;
  flex-wrap: wrap;
}

.article-category-badge {
  background: var(--cobalt-blue);
  color: #ffffff;
  padding: 2px 8px;
  font-weight: 800;
  font-size: 0.75rem;
}

/* 文章目录 (Table of Contents Box) */
.article-toc-box {
  border: 1px solid var(--border-rigid);
  background: var(--bg-surface);
  padding: 24px 28px;
  margin-bottom: 36px;
}

.toc-title {
  font-size: 1.05rem;
  font-weight: 900;
  letter-spacing: -0.3px;
  margin-bottom: 14px;
  display: flex;
  align-items: center;
  gap: 8px;
  text-transform: uppercase;
}

.toc-title::before {
  content: "§";
  color: var(--cobalt-blue);
  font-family: var(--font-mono);
  font-weight: 900;
}

.toc-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding-left: 0;
}

.toc-item {
  font-size: 0.92rem;
  line-height: 1.5;
}

.toc-link {
  color: var(--text-sub);
  text-decoration: none;
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  transition: color 0s;
}

.toc-link:hover {
  color: var(--cobalt-blue);
  text-decoration: underline;
  font-weight: 700;
}

.toc-num {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--cobalt-blue);
  font-weight: 800;
}

/* 文章正文 (Prose Content) */
.article-prose {
  color: var(--text-sub);
  font-size: 1.02rem;
  line-height: 1.85;
}

.article-prose h2 {
  font-size: 1.65rem;
  font-weight: 900;
  letter-spacing: -0.5px;
  color: var(--text-main);
  margin: 44px 0 18px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--border-rigid);
  display: flex;
  align-items: center;
  gap: 10px;
}

.article-prose h2::before {
  content: "#";
  color: var(--cobalt-blue);
  font-family: var(--font-mono);
}

.article-prose h3 {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--text-main);
  margin: 28px 0 12px;
}

.article-prose p {
  margin-bottom: 18px;
}

.article-prose strong {
  color: var(--text-main);
  font-weight: 800;
}

.article-prose ul, .article-prose ol {
  padding-left: 24px;
  margin-bottom: 20px;
}

.article-prose li {
  margin-bottom: 8px;
}

.article-prose .prose-link {
  color: var(--cobalt-blue);
  font-weight: 800;
  text-decoration: underline;
  text-underline-offset: 3px;
}

.article-prose .prose-link:hover {
  background: var(--cobalt-blue);
  color: #ffffff;
  text-decoration: none;
}

/* 正文数据对比表格 */
.prose-table {
  width: 100%;
  border-collapse: collapse;
  margin: 24px 0 28px;
  border: 1px solid var(--border-rigid);
}

.prose-table th, .prose-table td {
  border: 1px solid var(--border-subtle);
  padding: 12px 16px;
  font-size: 0.9rem;
  text-align: left;
}

.prose-table th {
  background: var(--bg-surface);
  font-weight: 900;
  color: var(--text-main);
  border-bottom: 2px solid var(--border-rigid);
  font-family: var(--font-mono);
  font-size: 0.85rem;
}

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

/* 核心要点警示框 */
.prose-callout {
  border: 1px solid var(--border-rigid);
  border-left: 6px solid var(--cobalt-blue);
  background: var(--bg-surface);
  padding: 20px 24px;
  margin: 28px 0;
}

.prose-callout.purple {
  border-left-color: var(--alert-purple);
}

.callout-title {
  font-weight: 900;
  font-size: 1rem;
  color: var(--text-main);
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 8px;
}

/* 文章内置FAQ */
.article-faq-wrap {
  margin: 44px 0;
  border: 1px solid var(--border-rigid);
  background: var(--border-rigid);
  display: flex;
  flex-direction: column;
  gap: 1px;
}

/* 文章相关推荐阅读网格 (Related Reading Grid) */
.related-reading-section {
  margin-top: 56px;
  border-top: 2px solid var(--border-rigid);
  padding-top: 36px;
}

.related-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  border: 1px solid var(--border-rigid);
  background: var(--border-rigid);
  gap: 1px;
  margin-top: 20px;
}

.related-card {
  background: var(--bg-pitch);
  padding: 20px 24px;
  display: flex;
  flex-direction: column;
  text-decoration: none;
  color: var(--text-main);
  transition: background-color 0s, color 0s;
}

.related-card:hover {
  background: var(--cobalt-blue);
  color: #ffffff;
}

.related-card:hover .related-date,
.related-card:hover .related-desc {
  color: #ffffff;
  opacity: 0.9;
}

.related-date {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--cobalt-blue);
  margin-bottom: 6px;
}

.related-title {
  font-size: 1.05rem;
  font-weight: 800;
  margin-bottom: 8px;
  line-height: 1.4;
}

.related-desc {
  font-size: 0.85rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* ===================================================================
   响应式断点适配 (@media queries) - 严格手机端单栏展示
=================================================================== */
@media (max-width: 992px) {
  .hero-title {
    font-size: 2.8rem;
  }
  .features-grid,
  .pricing-grid,
  .reviews-grid,
  .specialty-grid {
    grid-template-columns: 1fr;
  }
  .bandwidth-stats-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .nav-wrap {
    height: 60px;
  }
  .site-nav {
    display: none; /* 移动端导航紧凑折叠 */
  }
  .hero-section {
    padding: 36px 0 32px;
  }
  .hero-title {
    font-size: 2.1rem;
    transform: skewX(-8deg); /* 手机端稍收敛倾角，避免溢出 */
  }
  .hero-actions {
    flex-direction: column;
    width: 100%;
  }
  .hero-actions .btn {
    width: 100%;
    height: 48px;
  }
  .bandwidth-stats-grid {
    grid-template-columns: 1fr;
  }
  .node-table-grid {
    grid-template-columns: 1fr;
  }
  .footer-nav {
    flex-direction: column;
    gap: 0;
  }
  .footer-link {
    width: 100%;
    text-align: center;
    border-right: none;
    border-bottom: 1px solid var(--border-subtle);
    padding: 12px 0;
  }
  .footer-bottom {
    flex-direction: column;
    gap: 12px;
    text-align: center;
  }
  .page-container {
    padding: 0 16px;
    margin: 20px auto 40px;
  }
  .page-header-card,
  .page-body-card {
    padding: 24px 18px;
  }
}