/* ==========================================================================
   优信云 官方网站 - 样式表 (style.css)
   设计风格: Kinetic stacked disks (动力层叠圆盘)
   色彩系统: 
     暖白 (Warm White): #FBF9F5
     石墨黑灰 (Graphite): #31373A
     柔和藏红花金 (Muted Saffron): #C7A45E
     苍青蓝灰 (Pale Blue-Gray): #E8EEF0
   ========================================================================== */

:root {
  --color-warm-white: #FBF9F5;
  --color-warm-card: #FFFFFF;
  --color-graphite: #31373A;
  --color-graphite-dark: #1E2325;
  --color-graphite-muted: #5A6266;
  --color-graphite-subtle: #798286;
  --color-saffron: #C7A45E;
  --color-saffron-hover: #B5924B;
  --color-saffron-light: #F7F2E7;
  --color-saffron-border: rgba(199, 164, 94, 0.4);
  --color-blue-gray: #E8EEF0;
  --color-blue-gray-dark: #D3DDE1;
  --color-border: #E5EBEA;
  --color-border-hover: #C7A45E;
  
  --font-heading: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  --font-body: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-full: 9999px;
  
  --shadow-sm: 0 2px 8px rgba(49, 55, 58, 0.05);
  --shadow-md: 0 8px 24px rgba(49, 55, 58, 0.08);
  --shadow-lg: 0 16px 36px rgba(49, 55, 58, 0.12);
  --shadow-disk: 0 14px 28px rgba(49, 55, 58, 0.16);

  --max-width: 1240px;
  --transition-normal: 0.25s ease;
}

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

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

body {
  font-family: var(--font-body);
  font-size: 16px;
  font-weight: 400;
  line-height: 1.7;
  color: var(--color-graphite);
  background-color: var(--color-warm-white);
  overflow-x: hidden;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition-normal);
}

img, svg {
  max-width: 100%;
  height: auto;
  display: block;
}

button, input {
  font-family: inherit;
  font-size: inherit;
}

/* 版心容器 */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: 24px;
  padding-right: 24px;
}

/* 标题规范 */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  color: var(--color-graphite);
  line-height: 1.25;
  letter-spacing: -0.02em;
}

h1 {
  font-size: 62px;
  font-weight: 800;
  line-height: 1.15;
}

h2 {
  font-size: 36px;
  margin-bottom: 12px;
}

h3 {
  font-size: 22px;
  margin-bottom: 8px;
}

/* 辅助说明 */
.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-saffron);
  background: var(--color-saffron-light);
  border: 1px solid var(--color-saffron-border);
  padding: 5px 14px;
  border-radius: var(--radius-full);
  margin-bottom: 14px;
}

.section-tag::before {
  content: "";
  display: inline-block;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--color-saffron);
}

.section-header {
  text-align: center;
  max-width: 760px;
  margin: 0 auto 56px auto;
}

.section-header p {
  font-size: 17px;
  color: var(--color-graphite-muted);
}

/* 按钮规范 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 14px 28px;
  font-weight: 600;
  font-size: 15px;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  transition: all var(--transition-normal);
  text-align: center;
  white-space: nowrap;
}

.btn-primary {
  background-color: var(--color-saffron);
  color: #FFFFFF;
  border-color: var(--color-saffron);
  box-shadow: 0 4px 14px rgba(199, 164, 94, 0.35);
}

.btn-primary:hover {
  background-color: var(--color-saffron-hover);
  border-color: var(--color-saffron-hover);
  transform: translateY(-2px);
  box-shadow: 0 6px 18px rgba(199, 164, 94, 0.45);
}

.btn-secondary {
  background-color: var(--color-warm-card);
  color: var(--color-graphite);
  border-color: var(--color-graphite);
}

.btn-secondary:hover {
  background-color: var(--color-graphite);
  color: #FFFFFF;
  transform: translateY(-2px);
}

.btn-sm {
  padding: 8px 18px;
  font-size: 14px;
  border-radius: var(--radius-sm);
}

/* ==========================================================================
   Header 导航栏
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: rgba(251, 249, 245, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  transition: all var(--transition-normal);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 74px;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-heading);
  font-size: 22px;
  font-weight: 800;
  color: var(--color-graphite);
}

.brand-icon {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav-link {
  font-size: 15px;
  font-weight: 500;
  color: var(--color-graphite);
  position: relative;
  padding: 6px 0;
}

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

.nav-link::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--color-saffron);
  transition: width var(--transition-normal);
}

.nav-link:hover::after, .nav-link.active::after {
  width: 100%;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 14px;
}

/* 汉堡菜单开关 */
.menu-toggle {
  display: none;
  background: transparent;
  border: none;
  width: 40px;
  height: 40px;
  padding: 8px;
  cursor: pointer;
  flex-direction: column;
  justify-content: space-around;
  z-index: 1002;
}

.menu-toggle span {
  display: block;
  width: 100%;
  height: 2px;
  background-color: var(--color-graphite);
  border-radius: 2px;
  transition: all 0.3s ease;
}

.menu-toggle.is-active span:nth-child(1) {
  transform: translateY(8px) rotate(45deg);
}

.menu-toggle.is-active span:nth-child(2) {
  opacity: 0;
}

.menu-toggle.is-active span:nth-child(3) {
  transform: translateY(-8px) rotate(-45deg);
}

/* ==========================================================================
   Hero 主视觉区 (Kinetic stacked disks)
   ========================================================================== */
.hero-section {
  padding: 70px 0 90px 0;
  position: relative;
  overflow: hidden;
  background: linear-gradient(180deg, var(--color-warm-white) 0%, rgba(232, 238, 240, 0.4) 100%);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 1fr;
  gap: 48px;
  align-items: center;
}

.hero-copy {
  max-width: 620px;
}

.hero-copy h1 {
  margin-bottom: 20px;
  color: var(--color-graphite);
}

.hero-copy h1 .highlight {
  color: var(--color-saffron);
  display: block;
}

.hero-desc {
  font-size: 18px;
  color: var(--color-graphite-muted);
  line-height: 1.8;
  margin-bottom: 32px;
}

.hero-actions {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
  margin-bottom: 36px;
}

.hero-meta {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 24px;
  padding-top: 24px;
  border-top: 1px solid var(--color-border);
}

.meta-item {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  color: var(--color-graphite-subtle);
}

.meta-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--color-saffron);
}

/* Kinetic Stacked Disks 舞台 */
.hero-dashboard {
  position: relative;
  min-height: 520px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.disks-stage {
  position: relative;
  width: 100%;
  max-width: 480px;
  height: 480px;
  perspective: 1000px;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* 3D 倾斜容器 */
.disks-stack {
  position: relative;
  width: 360px;
  height: 360px;
  transform-style: preserve-3d;
  transform: rotateX(56deg) rotateZ(-20deg);
  transition: transform 0.5s ease;
}

/* 单个浅 3D 圆盘 */
.disk-layer {
  position: absolute;
  top: 50%;
  left: 50%;
  border-radius: 50%;
  transform-style: preserve-3d;
  border: 2px solid rgba(49, 55, 58, 0.15);
  box-shadow: var(--shadow-disk);
  will-change: transform;
}

/* 圆盘层级深度与尺寸 (由底到顶) */
.disk-4 {
  width: 350px;
  height: 350px;
  margin-top: -175px;
  margin-left: -175px;
  transform: translateZ(-90px);
  background: radial-gradient(circle, #31373A 0%, #1E2325 100%);
  border-color: #4D565B;
  animation: rotateDiskClockwise 75s linear infinite;
}

.disk-3 {
  width: 300px;
  height: 300px;
  margin-top: -150px;
  margin-left: -150px;
  transform: translateZ(-30px);
  background: radial-gradient(circle, #E8EEF0 0%, #D3DDE1 100%);
  border-color: #BAC7CD;
  animation: rotateDiskCounter 60s linear infinite;
}

.disk-2 {
  width: 240px;
  height: 240px;
  margin-top: -120px;
  margin-left: -120px;
  transform: translateZ(30px);
  background: radial-gradient(circle, #DFC48B 0%, #C7A45E 100%);
  border-color: #B5924B;
  animation: rotateDiskClockwise 48s linear infinite;
}

.disk-1 {
  width: 170px;
  height: 170px;
  margin-top: -85px;
  margin-left: -85px;
  transform: translateZ(90px);
  background: radial-gradient(circle, #31373A 0%, #171A1B 100%);
  border-color: #C7A45E;
  box-shadow: 0 0 20px rgba(199, 164, 94, 0.4), var(--shadow-disk);
  animation: rotateDiskCounter 38s linear infinite;
}

/* 圆盘表面网格刻度 (SVG/CSS 装饰) */
.disk-surface {
  position: absolute;
  inset: 0;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
}

.disk-ring-inner {
  position: absolute;
  border-radius: 50%;
  border: 1px dashed rgba(255, 255, 255, 0.4);
}

.disk-4 .disk-ring-inner {
  width: 75%;
  height: 75%;
  border-color: rgba(199, 164, 94, 0.3);
}

.disk-3 .disk-ring-inner {
  width: 70%;
  height: 70%;
  border-color: rgba(49, 55, 58, 0.2);
}

.disk-2 .disk-ring-inner {
  width: 65%;
  height: 65%;
  border-color: rgba(255, 255, 255, 0.5);
}

.disk-1 .disk-ring-inner {
  width: 60%;
  height: 60%;
  border-color: var(--color-saffron);
}

.disk-core {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background-color: var(--color-saffron);
  border: 3px solid #FBF9F5;
  box-shadow: 0 0 12px rgba(199, 164, 94, 0.6);
}

/* 动效旋转帧 */
@keyframes rotateDiskClockwise {
  from { transform: translateZ(var(--tz, 0)) rotate(0deg); }
  to { transform: translateZ(var(--tz, 0)) rotate(360deg); }
}

@keyframes rotateDiskCounter {
  from { transform: translateZ(var(--tz, 0)) rotate(0deg); }
  to { transform: translateZ(var(--tz, 0)) rotate(-360deg); }
}

.disk-4 { --tz: -90px; }
.disk-3 { --tz: -30px; }
.disk-2 { --tz: 30px; }
.disk-1 { --tz: 90px; }

/* 必须将所有关键内容置于动态圆盘外部：固定可读标签 (Fixed readable badges outside animated disks) */
.fixed-labels-layer {
  position: absolute;
  inset: 0;
  pointer-events: none;
}

.disk-callout {
  position: absolute;
  background-color: #FFFFFF;
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-md);
  padding: 10px 16px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 13px;
  font-weight: 700;
  color: var(--color-graphite);
  pointer-events: auto;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.disk-callout:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
  border-color: var(--color-saffron);
}

.callout-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background-color: var(--color-saffron);
}

.disk-callout.pos-top-right {
  top: 15px;
  right: -10px;
  border-left: 3px solid var(--color-saffron);
}

.disk-callout.pos-top-left {
  top: 95px;
  left: -20px;
  border-left: 3px solid var(--color-graphite);
}

.disk-callout.pos-bottom-right {
  bottom: 80px;
  right: -25px;
  border-left: 3px solid #3B82F6;
}

.disk-callout.pos-bottom-left {
  bottom: 20px;
  left: 0px;
  border-left: 3px solid #10B981;
}

.callout-sub {
  display: block;
  font-size: 11px;
  font-weight: 400;
  color: var(--color-graphite-subtle);
}

/* 当页面离开视口时暂停动画 (通过 JS IntersectionObserver 添加 .is-paused) */
.is-paused .disk-layer {
  animation-play-state: paused !important;
}

/* ==========================================================================
   核心优势 (Benefits - 3 advantages with circular diagrams and linear text)
   ========================================================================== */
.benefits-section {
  padding: 100px 0;
  background-color: var(--color-warm-white);
}

.benefits-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.benefit-card {
  background-color: var(--color-warm-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 36px 30px;
  transition: all var(--transition-normal);
  display: flex;
  flex-direction: column;
  position: relative;
}

.benefit-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: var(--color-saffron);
}

/* 圆形图示组件 (Circular Diagram) */
.circular-diagram-wrap {
  width: 96px;
  height: 96px;
  margin-bottom: 24px;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}

.circular-diagram-svg {
  width: 100%;
  height: 100%;
}

.benefit-title {
  font-size: 21px;
  font-weight: 700;
  color: var(--color-graphite);
  margin-bottom: 12px;
}

.benefit-text {
  font-size: 15px;
  color: var(--color-graphite-muted);
  line-height: 1.75;
  margin-bottom: 18px;
}

.benefit-points {
  list-style: none;
  margin-top: auto;
  border-top: 1px solid var(--color-blue-gray);
  padding-top: 16px;
}

.benefit-points li {
  font-size: 14px;
  color: var(--color-graphite);
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 8px;
}

.benefit-points li:last-child {
  margin-bottom: 0;
}

.point-icon {
  color: var(--color-saffron);
  font-weight: bold;
}

/* ==========================================================================
   全球节点网络 (Global Nodes - Clear Region Directory)
   ========================================================================== */
.nodes-section {
  padding: 90px 0;
  background-color: rgba(232, 238, 240, 0.45);
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}

.directory-table-card {
  background-color: #FFFFFF;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
}

.table-responsive {
  width: 100%;
  overflow-x: auto;
}

.region-directory-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 15px;
}

.region-directory-table th {
  background-color: var(--color-blue-gray);
  color: var(--color-graphite);
  font-weight: 700;
  padding: 16px 20px;
  border-bottom: 1px solid var(--color-border);
  white-space: nowrap;
}

.region-directory-table td {
  padding: 18px 20px;
  border-bottom: 1px solid var(--color-border);
  color: var(--color-graphite-muted);
}

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

.region-directory-table tr:hover td {
  background-color: rgba(251, 249, 245, 0.7);
}

.region-name-cell {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 700;
  color: var(--color-graphite);
}

.region-badge {
  display: inline-block;
  padding: 3px 8px;
  font-size: 12px;
  font-weight: 600;
  background-color: var(--color-blue-gray);
  color: var(--color-graphite);
  border-radius: var(--radius-sm);
}

.status-indicator {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  font-weight: 600;
  color: #10B981;
}

.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: #10B981;
}

.nodes-note-box {
  margin-top: 24px;
  padding: 16px 20px;
  background-color: var(--color-saffron-light);
  border: 1px solid var(--color-saffron-border);
  border-radius: var(--radius-md);
  font-size: 14px;
  color: var(--color-graphite);
  display: flex;
  align-items: flex-start;
  gap: 12px;
}

/* ==========================================================================
   AI 与流媒体场景展开 (AI & Streaming Scenarios - Separate Spreads)
   ========================================================================== */
.scenarios-section {
  padding: 100px 0;
  background-color: var(--color-warm-white);
}

.scenario-spread {
  background-color: #FFFFFF;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 44px;
  margin-bottom: 40px;
  box-shadow: var(--shadow-sm);
}

.scenario-spread:last-child {
  margin-bottom: 0;
}

.scenario-header-spread {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 24px;
  margin-bottom: 32px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--color-border);
}

.scenario-header-spread h3 {
  font-size: 26px;
  color: var(--color-graphite);
  margin-bottom: 8px;
}

.scenario-header-spread p {
  color: var(--color-graphite-muted);
  font-size: 16px;
  max-width: 680px;
}

.scenario-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.scenario-item-card {
  background-color: var(--color-warm-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 24px;
  transition: all var(--transition-normal);
}

.scenario-item-card:hover {
  border-color: var(--color-saffron);
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

.scenario-app-title {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 18px;
  font-weight: 700;
  color: var(--color-graphite);
  margin-bottom: 10px;
}

.scenario-app-icon {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: var(--color-blue-gray);
  color: var(--color-graphite);
  font-size: 14px;
  font-weight: 800;
}

.scenario-desc {
  font-size: 14px;
  color: var(--color-graphite-muted);
  line-height: 1.65;
  margin-bottom: 14px;
}

.scenario-tip {
  font-size: 12px;
  color: var(--color-graphite-subtle);
  background-color: rgba(232, 238, 240, 0.6);
  padding: 6px 10px;
  border-radius: var(--radius-sm);
}

/* ==========================================================================
   套餐价格 (Pricing - Rectangular comparison cards with tabular numerals)
   ========================================================================== */
.pricing-section {
  padding: 100px 0;
  background-color: rgba(232, 238, 240, 0.35);
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}

.pricing-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  align-items: stretch;
}

.pricing-card {
  background-color: #FFFFFF;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 36px 28px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: all var(--transition-normal);
}

.pricing-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: var(--color-graphite);
}

/* 推荐套餐高亮 (Exactly one 推荐套餐) */
.pricing-card.is-featured {
  border: 2px solid var(--color-saffron);
  box-shadow: 0 12px 32px rgba(199, 164, 94, 0.2);
  transform: scale(1.03);
  z-index: 2;
}

.pricing-card.is-featured:hover {
  transform: scale(1.03) translateY(-4px);
  box-shadow: 0 16px 36px rgba(199, 164, 94, 0.3);
}

.featured-badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background-color: var(--color-saffron);
  color: #FFFFFF;
  font-size: 12px;
  font-weight: 700;
  padding: 4px 16px;
  border-radius: var(--radius-full);
  letter-spacing: 0.05em;
  box-shadow: 0 2px 8px rgba(199, 164, 94, 0.4);
}

.tier-name {
  font-size: 20px;
  font-weight: 700;
  color: var(--color-graphite);
  margin-bottom: 6px;
}

.tier-desc {
  font-size: 13px;
  color: var(--color-graphite-muted);
  margin-bottom: 22px;
  min-height: 38px;
}

/* 表格数字与价格 */
.tier-price-box {
  display: flex;
  align-items: baseline;
  gap: 4px;
  margin-bottom: 24px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--color-border);
}

.price-currency {
  font-size: 20px;
  font-weight: 600;
  color: var(--color-graphite);
}

.price-amount {
  font-size: 44px;
  font-weight: 800;
  color: var(--color-graphite);
  line-height: 1;
  font-variant-numeric: tabular-nums;
  font-feature-settings: "tnum";
}

.price-period {
  font-size: 14px;
  color: var(--color-graphite-subtle);
  margin-left: 2px;
}

.tier-features {
  list-style: none;
  margin-bottom: 28px;
  flex-grow: 1;
}

.tier-features li {
  font-size: 14px;
  color: var(--color-graphite);
  margin-bottom: 12px;
  display: flex;
  align-items: flex-start;
  gap: 8px;
  line-height: 1.5;
}

.tier-features li.dimmed {
  color: var(--color-graphite-subtle);
}

.check-mark {
  color: var(--color-saffron);
  font-weight: bold;
  flex-shrink: 0;
}

.pricing-note-disclaimer {
  margin-top: 36px;
  text-align: center;
  font-size: 13px;
  color: var(--color-graphite-subtle);
}

/* ==========================================================================
   文章区域 (Nine Articles Cards - 3 desktop / 2 tablet / 1 mobile columns)
   ========================================================================== */
.articles-section {
  padding: 100px 0;
  background-color: var(--color-warm-white);
}

.articles-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
}

.article-card {
  background-color: #FFFFFF;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 28px;
  display: flex;
  flex-direction: column;
  transition: all var(--transition-normal);
  position: relative;
}

.article-card:hover {
  transform: translateY(-4px);
  border-color: var(--color-saffron);
  box-shadow: var(--shadow-md);
}

.article-meta-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 12px;
  color: var(--color-graphite-subtle);
  margin-bottom: 14px;
}

.article-category {
  font-weight: 700;
  color: var(--color-saffron);
  background-color: var(--color-saffron-light);
  padding: 3px 10px;
  border-radius: var(--radius-full);
}

.article-card-title {
  font-size: 19px;
  font-weight: 700;
  line-height: 1.4;
  margin-bottom: 12px;
  color: var(--color-graphite);
  transition: color var(--transition-normal);
}

.article-card:hover .article-card-title {
  color: var(--color-saffron);
}

.article-card-desc {
  font-size: 14px;
  color: var(--color-graphite-muted);
  line-height: 1.65;
  margin-bottom: 20px;
  flex-grow: 1;
}

.article-read-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-graphite);
  margin-top: auto;
  transition: color var(--transition-normal);
}

.article-card:hover .article-read-link {
  color: var(--color-saffron);
}

/* ==========================================================================
   用户评价 (Testimonials - Clearly sample/editorial feedback, truthful)
   ========================================================================== */
.testimonials-section {
  padding: 90px 0;
  background-color: rgba(232, 238, 240, 0.4);
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}

.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.testimonial-card {
  background-color: #FFFFFF;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 30px;
  display: flex;
  flex-direction: column;
}

.testimonial-badge-sample {
  display: inline-block;
  font-size: 11px;
  color: var(--color-graphite-subtle);
  background-color: var(--color-blue-gray);
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  align-self: flex-start;
  margin-bottom: 14px;
}

.testimonial-text {
  font-size: 15px;
  color: var(--color-graphite);
  line-height: 1.75;
  margin-bottom: 20px;
  flex-grow: 1;
  font-style: normal;
}

.testimonial-author-box {
  display: flex;
  align-items: center;
  gap: 12px;
  border-top: 1px solid var(--color-border);
  padding-top: 16px;
}

.author-avatar {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background-color: var(--color-saffron-light);
  color: var(--color-saffron);
  border: 1px solid var(--color-saffron-border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 14px;
}

.author-info h4 {
  font-size: 14px;
  font-weight: 700;
  margin-bottom: 2px;
}

.author-info span {
  font-size: 12px;
  color: var(--color-graphite-subtle);
}

/* ==========================================================================
   FAQ 手风琴 (FAQ Accordion)
   ========================================================================== */
.faq-section {
  padding: 100px 0;
  background-color: var(--color-warm-white);
}

.faq-accordion-wrap {
  max-width: 820px;
  margin: 0 auto;
}

.faq-item {
  background-color: #FFFFFF;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  margin-bottom: 14px;
  overflow: hidden;
  transition: border-color var(--transition-normal);
}

.faq-item:hover {
  border-color: var(--color-saffron);
}

.faq-question-btn {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 22px 24px;
  background: transparent;
  border: none;
  font-family: var(--font-heading);
  font-size: 17px;
  font-weight: 700;
  color: var(--color-graphite);
  text-align: left;
  cursor: pointer;
  transition: color var(--transition-normal);
}

.faq-icon-arrow {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
  transition: transform 0.3s ease;
  stroke: var(--color-graphite-muted);
}

.faq-item.is-open .faq-icon-arrow {
  transform: rotate(180deg);
  stroke: var(--color-saffron);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease, padding 0.35s ease;
  padding: 0 24px;
}

.faq-item.is-open .faq-answer {
  max-height: 400px;
  padding: 0 24px 22px 24px;
}

.faq-answer p {
  font-size: 15px;
  color: var(--color-graphite-muted);
  line-height: 1.75;
}

/* ==========================================================================
   Footer 页脚
   ========================================================================== */
.site-footer {
  background-color: var(--color-graphite);
  color: #E8EEF0;
  padding: 80px 0 40px 0;
  font-size: 14px;
  border-top: 1px solid #434B4F;
}

.footer-top {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 60px;
}

.footer-brand h3 {
  color: #FFFFFF;
  font-size: 22px;
  margin-bottom: 14px;
}

.footer-brand p {
  color: #A3AFB4;
  line-height: 1.7;
  margin-bottom: 20px;
  max-width: 340px;
}

.footer-col h4 {
  color: #FFFFFF;
  font-size: 16px;
  margin-bottom: 20px;
}

.footer-links-list {
  list-style: none;
}

.footer-links-list li {
  margin-bottom: 12px;
}

.footer-links-list a {
  color: #A3AFB4;
}

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

/* 关联站点推荐行 (包含 jichanghelper, tizivpnhelp, tizicloud) */
.footer-partner-strip {
  border-top: 1px solid #434B4F;
  border-bottom: 1px solid #434B4F;
  padding: 24px 0;
  margin-bottom: 30px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
}

.partner-heading {
  font-weight: 700;
  color: #FFFFFF;
  font-size: 14px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.partner-links {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 24px;
}

.partner-link-item {
  color: var(--color-saffron);
  font-weight: 600;
  transition: color var(--transition-normal);
}

.partner-link-item:hover {
  color: #DFC48B;
  text-decoration: underline;
}

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
  color: #7E8D93;
  font-size: 13px;
}

/* ==========================================================================
   独立文章页与内页专属样式 (Article Detail & Static Pages)
   ========================================================================== */
.page-hero {
  padding: 56px 0 40px 0;
  background: linear-gradient(180deg, var(--color-warm-white) 0%, rgba(232, 238, 240, 0.5) 100%);
  border-bottom: 1px solid var(--color-border);
}

.breadcrumb-nav {
  margin-bottom: 20px;
  font-size: 14px;
  color: var(--color-graphite-subtle);
}

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

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

.breadcrumb-separator {
  margin: 0 8px;
}

.page-title {
  font-size: 44px;
  font-weight: 800;
  line-height: 1.25;
  margin-bottom: 16px;
  color: var(--color-graphite);
}

.article-meta-bar {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 20px;
  font-size: 14px;
  color: var(--color-graphite-subtle);
  margin-top: 18px;
}

.article-content-layout {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 50px;
  padding: 60px 0 100px 0;
}

.article-main-body {
  background-color: #FFFFFF;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 48px;
  box-shadow: var(--shadow-sm);
  overflow-wrap: break-word;
}

/* 文章正文排版规范 */
.article-main-body h2 {
  font-size: 26px;
  margin-top: 40px;
  margin-bottom: 18px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--color-blue-gray);
  color: var(--color-graphite);
}

.article-main-body h2:first-of-type {
  margin-top: 0;
}

.article-main-body h3 {
  font-size: 20px;
  margin-top: 28px;
  margin-bottom: 14px;
  color: var(--color-graphite);
}

.article-main-body p {
  font-size: 16px;
  line-height: 1.85;
  color: #3C4245;
  margin-bottom: 20px;
}

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

.article-main-body li {
  font-size: 16px;
  line-height: 1.8;
  color: #3C4245;
  margin-bottom: 10px;
}

.article-main-body strong {
  color: var(--color-graphite);
  font-weight: 700;
}

.article-callout-box {
  background-color: var(--color-warm-white);
  border-left: 4px solid var(--color-saffron);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  padding: 20px 24px;
  margin: 28px 0;
}

.article-callout-box p {
  margin-bottom: 0;
  font-size: 15px;
  color: var(--color-graphite);
}

/* 表格排版 */
.article-table {
  width: 100%;
  border-collapse: collapse;
  margin: 28px 0;
  font-size: 15px;
}

.article-table th {
  background-color: var(--color-blue-gray);
  color: var(--color-graphite);
  font-weight: 700;
  padding: 12px 16px;
  border: 1px solid var(--color-border);
  text-align: left;
}

.article-table td {
  padding: 12px 16px;
  border: 1px solid var(--color-border);
  color: var(--color-graphite-muted);
}

.article-table tr:nth-child(even) td {
  background-color: #FAFCFC;
}

/* 侧边栏 */
.article-sidebar {
  display: flex;
  flex-direction: column;
  gap: 30px;
}

.sidebar-widget {
  background-color: #FFFFFF;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 26px;
  box-shadow: var(--shadow-sm);
}

.sidebar-widget h4 {
  font-size: 18px;
  margin-bottom: 18px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--color-border);
}

.sidebar-links {
  list-style: none;
}

.sidebar-links li {
  margin-bottom: 14px;
}

.sidebar-links li:last-child {
  margin-bottom: 0;
}

.sidebar-links a {
  font-size: 14px;
  line-height: 1.5;
  color: var(--color-graphite);
  display: block;
}

.sidebar-links a:hover {
  color: var(--color-saffron);
}

/* ==========================================================================
   移动端与多分辨率适配 (Responsive Breakpoints: 375, 390, 430, 768, 1024, 1440)
   ========================================================================== */

/* 1024px 及以下 (Tablet / Small Desktop) */
@media (max-width: 1024px) {
  h1 {
    font-size: 48px;
  }
  
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }
  
  .hero-copy {
    max-width: 100%;
    text-align: center;
  }
  
  .hero-actions {
    justify-content: center;
  }
  
  .hero-meta {
    justify-content: center;
  }
  
  .pricing-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
  }
  
  .pricing-card.is-featured {
    transform: none;
  }
  
  .pricing-card.is-featured:hover {
    transform: translateY(-4px);
  }
  
  .articles-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .scenario-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .footer-top {
    grid-template-columns: 1fr 1fr;
    gap: 30px;
  }
  
  .article-content-layout {
    grid-template-columns: 1fr;
  }
}

/* 768px 及以下 (Mobile & Portrait Tablet) */
@media (max-width: 768px) {
  h1 {
    font-size: 38px;
  }
  
  h2 {
    font-size: 28px;
  }
  
  .section-header {
    margin-bottom: 40px;
  }
  
  /* 移动端汉堡导航切换 */
  .menu-toggle {
    display: flex;
  }
  
  .main-nav {
    position: fixed;
    top: 74px;
    left: 0;
    width: 100%;
    background-color: #FFFFFF;
    flex-direction: column;
    padding: 30px 24px;
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow-lg);
    gap: 18px;
    transform: translateY(-120%);
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    z-index: 999;
  }
  
  .main-nav.is-open {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }
  
  .nav-link {
    font-size: 16px;
    width: 100%;
    padding: 10px 0;
    border-bottom: 1px solid var(--color-blue-gray);
  }
  
  .header-actions .btn-sm {
    display: none;
  }
  
  /* 移动端圆盘简化 */
  .hero-dashboard {
    min-height: 380px;
  }
  
  .disks-stage {
    max-width: 340px;
    height: 340px;
  }
  
  .disks-stack {
    width: 280px;
    height: 280px;
    transform: rotateX(45deg) rotateZ(-10deg);
  }
  
  .disk-4 { width: 270px; height: 270px; margin-top: -135px; margin-left: -135px; }
  .disk-3 { width: 230px; height: 230px; margin-top: -115px; margin-left: -115px; }
  .disk-2 { width: 190px; height: 190px; margin-top: -95px; margin-left: -95px; }
  .disk-1 { width: 140px; height: 140px; margin-top: -70px; margin-left: -70px; }
  
  .disk-callout {
    padding: 6px 10px;
    font-size: 11px;
  }
  
  .disk-callout.pos-top-right { top: 0px; right: 0px; }
  .disk-callout.pos-top-left { top: 60px; left: 0px; }
  .disk-callout.pos-bottom-right { bottom: 40px; right: 0px; }
  .disk-callout.pos-bottom-left { bottom: 0px; left: 0px; }
  
  .benefits-grid {
    grid-template-columns: 1fr;
  }
  
  .pricing-grid {
    grid-template-columns: 1fr;
  }
  
  .articles-grid {
    grid-template-columns: 1fr;
  }
  
  .testimonials-grid {
    grid-template-columns: 1fr;
  }
  
  .scenario-grid {
    grid-template-columns: 1fr;
  }
  
  .scenario-header-spread {
    flex-direction: column;
  }
  
  .footer-top {
    grid-template-columns: 1fr;
  }
  
  .footer-partner-strip {
    flex-direction: column;
    align-items: flex-start;
  }
  
  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
  }
  
  .article-main-body {
    padding: 28px 20px;
  }
}

/* 430px / 390px / 375px 超小屏手机适配 */
@media (max-width: 430px) {
  h1 {
    font-size: 34px;
  }
  
  .container {
    padding-left: 16px;
    padding-right: 16px;
  }
  
  .btn {
    width: 100%;
    padding: 12px 20px;
  }
  
  .hero-actions {
    flex-direction: column;
    width: 100%;
  }
  
  .price-amount {
    font-size: 38px;
  }
}

/* 遵循用户的减少动效系统设置 (Honor prefers-reduced-motion) */
@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;
  }
  
  .disk-layer {
    animation: none !important;
  }
}