/* ===================================================================
   云梯 (yunti.cyou) 官方品牌样式表 - 云端阶梯式视觉体系
   色彩体系: 天空蓝 (#0284c7, #38bdf8), 银白 (#f8fafc, #ffffff), 
            冰川蓝 (#bae6fd, #e0f2fe), 深海蓝 (#0a192f, #0f172a, #1e293b)
   =================================================================== */

:root {
  /* 品牌调色板 */
  --sky-blue: #0284c7;
  --sky-blue-light: #38bdf8;
  --sky-blue-glow: rgba(56, 189, 248, 0.25);
  --glacier-blue: #e0f2fe;
  --glacier-blue-subtle: #f0f9ff;
  --glacier-border: #bae6fd;
  --deep-sea-dark: #0a192f;
  --deep-sea-card: #0f172a;
  --deep-sea-surface: #1e293b;
  --silver-white: #f8fafc;
  --silver-text: #f1f5f9;
  --text-muted: #94a3b8;
  --text-dim: #64748b;
  --accent-gold: #fbbf24;
  --success-color: #10b981;
  --warning-color: #f59e0b;

  /* 基础排版 */
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  
  /* 布局与阴影 */
  --container-max: 1160px;
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --shadow-subtle: 0 4px 20px -2px rgba(10, 25, 47, 0.4);
  --shadow-glow: 0 0 25px rgba(56, 189, 248, 0.35);
  --transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

/* 全局重置与基础规范 */
*, *::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-sans);
  background-color: var(--deep-sea-dark);
  color: var(--silver-text);
  line-height: 1.7;
  overflow-x: hidden;
  position: relative;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* 链接全局规范 */
a {
  color: var(--sky-blue-light);
  text-decoration: none;
  transition: var(--transition);
}

a:hover, a:focus-visible {
  color: #fff;
  text-decoration: underline;
}

/* 通用容器 */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* 按钮通用规范 (触控目标保障 44px+) */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0.75rem 1.75rem;
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  text-decoration: none;
  transition: var(--transition);
  text-align: center;
  gap: 0.5rem;
}

.btn-primary {
  background: linear-gradient(135deg, var(--sky-blue) 0%, var(--sky-blue-light) 100%);
  color: var(--deep-sea-dark);
  box-shadow: 0 4px 15px rgba(2, 132, 199, 0.4);
}

.btn-primary:hover, .btn-primary:focus-visible {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(56, 189, 248, 0.6);
  color: var(--deep-sea-dark);
  text-decoration: none;
}

.btn-secondary {
  background: rgba(30, 41, 59, 0.8);
  color: var(--silver-text);
  border: 1px solid var(--glacier-border);
}

.btn-secondary:hover, .btn-secondary:focus-visible {
  background: var(--deep-sea-surface);
  border-color: var(--sky-blue-light);
  color: #fff;
  text-decoration: none;
}

/* ===================================================================
   云端背景与阶梯视觉层 (Staircase & Drifting Clouds Motif)
   =================================================================== */

.sky-background {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 720px;
  background: radial-gradient(circle at 50% 15%, rgba(2, 132, 199, 0.25) 0%, rgba(10, 25, 47, 0) 70%),
              linear-gradient(180deg, rgba(15, 23, 42, 0.95) 0%, var(--deep-sea-dark) 100%);
  z-index: -2;
  overflow: hidden;
  pointer-events: none;
}

/* 缓慢漂移的云层 */
.drifting-cloud {
  position: absolute;
  background: radial-gradient(ellipse at center, rgba(186, 230, 253, 0.15) 0%, rgba(255, 255, 255, 0) 70%);
  filter: blur(25px);
  border-radius: 50%;
  pointer-events: none;
  animation: cloudDrift 60s infinite linear alternate;
}

.cloud-layer-1 {
  width: 650px;
  height: 260px;
  top: 80px;
  left: -150px;
  animation-duration: 75s;
}

.cloud-layer-2 {
  width: 780px;
  height: 320px;
  top: 200px;
  right: -200px;
  animation-duration: 90s;
  animation-delay: -30s;
}

.cloud-layer-3 {
  width: 500px;
  height: 200px;
  top: 380px;
  left: 20%;
  animation-duration: 65s;
  animation-delay: -15s;
}

@keyframes cloudDrift {
  0% {
    transform: translateX(-50px) translateY(0);
  }
  50% {
    transform: translateX(60px) translateY(20px);
  }
  100% {
    transform: translateX(120px) translateY(-10px);
  }
}

/* 阶梯几何装饰 */
.staircase-visual {
  position: relative;
  display: flex;
  justify-content: center;
  align-items: flex-end;
  gap: 8px;
  margin: 2rem auto;
  height: 120px;
  width: 240px;
  opacity: 0.85;
}

.stair-step {
  flex: 1;
  background: linear-gradient(180deg, var(--sky-blue-light) 0%, var(--sky-blue) 100%);
  border-radius: 4px 4px 0 0;
  box-shadow: 0 0 15px rgba(56, 189, 248, 0.4);
  transition: var(--transition);
}

.step-1 { height: 25%; }
.step-2 { height: 45%; }
.step-3 { height: 65%; }
.step-4 { height: 85%; }
.step-5 { height: 100%; }

/* ===================================================================
   导航栏 Header
   =================================================================== */

.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  background: rgba(10, 25, 47, 0.85);
  border-bottom: 1px solid rgba(56, 189, 248, 0.15);
  transition: var(--transition);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.brand-logo-link {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: var(--silver-text);
  font-size: 1.35rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.brand-logo-link:hover {
  text-decoration: none;
  color: var(--sky-blue-light);
}

.brand-logo-icon {
  width: 36px;
  height: 36px;
  flex-shrink: 0;
}

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

.nav-link {
  color: var(--text-muted);
  font-weight: 500;
  font-size: 0.95rem;
  padding: 0.5rem 0.25rem;
  border-bottom: 2px solid transparent;
  text-decoration: none;
}

.nav-link:hover, .nav-link.active {
  color: var(--sky-blue-light);
  border-bottom-color: var(--sky-blue-light);
  text-decoration: none;
}

.header-action-btn {
  margin-left: 0.5rem;
}

/* 移动端菜单按钮 */
.mobile-menu-toggle {
  display: none;
  background: none;
  border: 1px solid var(--deep-sea-surface);
  border-radius: var(--radius-sm);
  color: var(--silver-text);
  padding: 0.5rem;
  cursor: pointer;
  min-height: 44px;
  min-width: 44px;
  align-items: center;
  justify-content: center;
}

.mobile-menu-toggle svg {
  width: 24px;
  height: 24px;
}

.nav-mobile {
  display: none;
  background: var(--deep-sea-card);
  border-bottom: 1px solid rgba(56, 189, 248, 0.2);
  padding: 1rem 1.5rem 1.5rem;
}

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

.nav-mobile .nav-link {
  display: block;
  padding: 0.75rem 0;
  font-size: 1.05rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.nav-mobile .btn {
  width: 100%;
  margin-top: 1rem;
}

/* ===================================================================
   首页 Hero: 居中展示品牌宣言与云端阶梯
   =================================================================== */

.hero-section {
  padding: 4.5rem 0 3.5rem;
  text-align: center;
  position: relative;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 1rem;
  background: rgba(56, 189, 248, 0.1);
  border: 1px solid rgba(56, 189, 248, 0.3);
  border-radius: 999px;
  color: var(--sky-blue-light);
  font-size: 0.88rem;
  font-weight: 500;
  margin-bottom: 1.5rem;
}

.hero-title {
  font-size: clamp(2.2rem, 5vw, 3.4rem);
  font-weight: 800;
  line-height: 1.25;
  margin-bottom: 1.25rem;
  letter-spacing: -0.03em;
  background: linear-gradient(135deg, #ffffff 30%, var(--glacier-blue) 70%, var(--sky-blue-light) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-manifesto {
  font-size: clamp(1.05rem, 2.5vw, 1.25rem);
  color: var(--silver-text);
  max-width: 780px;
  margin: 0 auto 2rem;
  line-height: 1.8;
  font-weight: 400;
}

.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  flex-wrap: wrap;
  margin-bottom: 2rem;
}

.hero-note {
  font-size: 0.88rem;
  color: var(--text-dim);
}

/* ===================================================================
   三栏已核实服务特点 (Three-Column Verified Features)
   =================================================================== */

.features-section {
  padding: 3.5rem 0;
}

.section-header {
  text-align: center;
  max-width: 700px;
  margin: 0 auto 3rem;
}

.section-subtitle {
  color: var(--sky-blue-light);
  font-size: 0.9rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 0.5rem;
}

.section-title {
  font-size: clamp(1.8rem, 3.5vw, 2.4rem);
  font-weight: 700;
  color: #fff;
  line-height: 1.3;
  margin-bottom: 0.75rem;
}

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

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

.feature-card {
  background: linear-gradient(180deg, var(--deep-sea-card) 0%, rgba(15, 23, 42, 0.6) 100%);
  border: 1px solid rgba(56, 189, 248, 0.15);
  border-radius: var(--radius-lg);
  padding: 2rem 1.75rem;
  transition: var(--transition);
  position: relative;
  display: flex;
  flex-direction: column;
}

.feature-card:hover {
  transform: translateY(-4px);
  border-color: rgba(56, 189, 248, 0.4);
  box-shadow: 0 12px 30px rgba(2, 132, 199, 0.15);
}

.feature-icon-wrapper {
  width: 52px;
  height: 52px;
  background: rgba(56, 189, 248, 0.12);
  border: 1px solid rgba(56, 189, 248, 0.3);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--sky-blue-light);
  margin-bottom: 1.25rem;
}

.feature-badge {
  align-self: flex-start;
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.2rem 0.6rem;
  border-radius: 4px;
  background: rgba(56, 189, 248, 0.15);
  color: var(--sky-blue-light);
  margin-bottom: 0.75rem;
}

.feature-card-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 0.75rem;
}

.feature-card-desc {
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.7;
}

/* ===================================================================
   套餐说明与理性选型指导 (Service / Plan Explanation)
   =================================================================== */

.plan-guide-section {
  padding: 3.5rem 0;
  background: linear-gradient(180deg, rgba(15, 23, 42, 0) 0%, rgba(15, 23, 42, 0.7) 50%, rgba(15, 23, 42, 0) 100%);
}

/* ===================================================================
   套餐卡片网格 (Featured Plan Cards)
   =================================================================== */

.plans-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
  margin-bottom: 3rem;
}

.plan-card {
  background: var(--deep-sea-card);
  border: 1px solid rgba(56, 189, 248, 0.18);
  border-radius: var(--radius-lg);
  padding: 2.25rem 1.75rem 2rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: var(--transition);
  position: relative;
  box-shadow: var(--shadow-subtle);
}

.plan-card:hover {
  transform: translateY(-4px);
  border-color: rgba(56, 189, 248, 0.45);
  box-shadow: 0 14px 35px rgba(2, 132, 199, 0.2);
}

.plan-card.featured {
  border-color: var(--sky-blue-light);
  box-shadow: 0 0 30px rgba(56, 189, 248, 0.25), var(--shadow-subtle);
  background: linear-gradient(180deg, rgba(15, 23, 42, 0.95) 0%, rgba(30, 58, 138, 0.2) 100%);
}

.plan-badge {
  position: absolute;
  top: -12px;
  right: 24px;
  background: linear-gradient(135deg, var(--sky-blue) 0%, var(--sky-blue-light) 100%);
  color: var(--deep-sea-dark);
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.25rem 0.8rem;
  border-radius: 999px;
  box-shadow: 0 2px 10px rgba(56, 189, 248, 0.5);
}

.plan-tag-subtle {
  align-self: flex-start;
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--sky-blue-light);
  background: rgba(56, 189, 248, 0.12);
  border: 1px solid rgba(56, 189, 248, 0.25);
  padding: 0.2rem 0.65rem;
  border-radius: 6px;
  margin-bottom: 1rem;
  display: inline-block;
}

.plan-title {
  font-size: 1.35rem;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 0.75rem;
}

.plan-price-wrap {
  display: flex;
  align-items: baseline;
  gap: 4px;
  margin-bottom: 0.5rem;
}

.plan-price-currency {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--sky-blue-light);
}

.plan-price-amount {
  font-size: 2.5rem;
  font-weight: 800;
  color: #ffffff;
  line-height: 1;
}

.plan-price-period {
  font-size: 0.92rem;
  color: var(--text-muted);
}

.plan-traffic-highlight {
  font-size: 0.98rem;
  font-weight: 600;
  color: var(--glacier-border);
  margin-bottom: 0.25rem;
}

.plan-traffic-sub {
  font-size: 0.82rem;
  color: var(--text-dim);
  margin-bottom: 1.25rem;
}

.plan-target-desc {
  font-size: 0.88rem;
  color: var(--silver-text);
  background: rgba(255, 255, 255, 0.04);
  border-radius: var(--radius-sm);
  padding: 0.65rem 0.85rem;
  margin-bottom: 1.25rem;
  line-height: 1.5;
}

.plan-features-list {
  list-style: none;
  margin: 0 0 1.75rem 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

.plan-features-list li {
  font-size: 0.9rem;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 8px;
}

.plan-feature-check {
  color: var(--sky-blue-light);
  font-weight: bold;
  flex-shrink: 0;
}

.plan-btn-wrap {
  margin-top: auto;
}

.plan-btn-wrap .btn {
  width: 100%;
}

.plan-notice-card {
  background: rgba(15, 23, 42, 0.85);
  border: 1px solid var(--glacier-border);
  border-radius: var(--radius-lg);
  padding: 2rem;
  margin-bottom: 2.5rem;
  position: relative;
  overflow: hidden;
}

.plan-notice-header {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1rem;
}

.notice-status-tag {
  background: rgba(245, 158, 11, 0.2);
  border: 1px solid rgba(245, 158, 11, 0.5);
  color: var(--accent-gold);
  font-size: 0.8rem;
  font-weight: 600;
  padding: 0.2rem 0.75rem;
  border-radius: 999px;
}

.plan-notice-title {
  font-size: 1.3rem;
  font-weight: 700;
  color: #fff;
}

.plan-notice-body {
  color: var(--text-muted);
  font-size: 0.98rem;
  line-height: 1.8;
}

.plan-dimensions-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
}

.plan-dim-card {
  background: var(--deep-sea-surface);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: var(--radius-md);
  padding: 1.5rem;
}

.plan-dim-title {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--sky-blue-light);
  margin-bottom: 0.5rem;
}

.plan-dim-desc {
  font-size: 0.92rem;
  color: var(--text-muted);
  line-height: 1.65;
}

/* ===================================================================
   文章列表与卡片样式 (Articles Grid & Cards)
   =================================================================== */

.articles-section {
  padding: 3.5rem 0;
}

.articles-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

.article-card {
  background: var(--deep-sea-card);
  border: 1px solid rgba(56, 189, 248, 0.12);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: var(--transition);
}

.article-card:hover {
  transform: translateY(-3px);
  border-color: rgba(56, 189, 248, 0.35);
  box-shadow: 0 10px 25px rgba(2, 132, 199, 0.12);
}

.article-meta-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.82rem;
  color: var(--text-dim);
  margin-bottom: 0.85rem;
}

.article-card-title {
  font-size: 1.15rem;
  font-weight: 700;
  line-height: 1.45;
  margin-bottom: 0.75rem;
}

.article-card-title a {
  color: #fff;
  text-decoration: none;
}

.article-card-title a:hover {
  color: var(--sky-blue-light);
}

.article-card-desc {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.65;
  margin-bottom: 1.25rem;
}

.article-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 1rem;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  font-size: 0.88rem;
}

/* ===================================================================
   用户反馈与评价区域 (User Reviews & Testimonials - 图二模式)
   =================================================================== */

.feedback-section {
  padding: 3.5rem 0;
  position: relative;
}

.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

.review-card {
  background: var(--deep-sea-card);
  border: 1px solid rgba(56, 189, 248, 0.18);
  border-radius: var(--radius-lg);
  padding: 2.25rem 1.75rem 1.75rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  box-shadow: var(--shadow-subtle);
  transition: var(--transition);
  position: relative;
}

.review-card:hover {
  transform: translateY(-4px);
  border-color: rgba(56, 189, 248, 0.45);
  box-shadow: 0 12px 30px rgba(2, 132, 199, 0.18);
}

.review-stars {
  color: #f59e0b;
  font-size: 1.15rem;
  letter-spacing: 3px;
  margin-bottom: 1.25rem;
  line-height: 1;
}

.review-text {
  font-size: 0.96rem;
  color: #e2e8f0;
  line-height: 1.8;
  margin-bottom: 1.75rem;
  flex-grow: 1;
}

.review-user-info {
  display: flex;
  align-items: center;
  gap: 12px;
  padding-top: 1.25rem;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.review-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1.05rem;
  color: #ffffff;
  flex-shrink: 0;
  background: linear-gradient(135deg, var(--sky-blue) 0%, var(--sky-blue-light) 100%);
  box-shadow: 0 4px 10px rgba(2, 132, 199, 0.35);
}

.review-user-meta {
  display: flex;
  flex-direction: column;
}

.review-user-name {
  font-size: 1rem;
  font-weight: 700;
  color: #ffffff;
  line-height: 1.3;
}

.review-user-role {
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-top: 2px;
  line-height: 1.4;
}

/* ===================================================================
   常见问题 FAQ 手风琴
   =================================================================== */

.faq-section {
  padding: 3.5rem 0;
}

.faq-list {
  max-width: 860px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.faq-item {
  background: var(--deep-sea-card);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: var(--transition);
}

.faq-item:hover {
  border-color: rgba(56, 189, 248, 0.25);
}

.faq-question-btn {
  width: 100%;
  padding: 1.25rem 1.5rem;
  background: none;
  border: none;
  text-align: left;
  display: flex;
  align-items: center;
  justify-content: space-between;
  color: #fff;
  font-size: 1.05rem;
  font-weight: 600;
  cursor: pointer;
  min-height: 52px;
}

.faq-question-btn:focus-visible {
  outline: 2px solid var(--sky-blue-light);
}

.faq-icon {
  width: 20px;
  height: 20px;
  transition: transform 0.25s ease;
  color: var(--sky-blue-light);
  flex-shrink: 0;
}

.faq-item.active .faq-icon {
  transform: rotate(180deg);
}

.faq-answer {
  display: none;
  padding: 0 1.5rem 1.25rem;
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.75;
}

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

/* ===================================================================
   页脚 Footer
   =================================================================== */

.site-footer {
  margin-top: auto;
  background: #070d18;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding: 3rem 0 2rem;
  color: var(--text-dim);
  font-size: 0.9rem;
}

.footer-top {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: 2rem;
  margin-bottom: 2rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.footer-brand-col {
  max-width: 380px;
}

.footer-brand-title {
  font-size: 1.2rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 0.5rem;
}

.footer-links-group {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem 2rem;
}

.footer-links-group a {
  color: var(--text-muted);
  font-size: 0.9rem;
}

.footer-links-group a:hover {
  color: var(--sky-blue-light);
}

.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  padding-bottom: env(safe-area-inset-bottom, 0);
}

/* ===================================================================
   文章内页排版 (Article Detail Page Typography)
   =================================================================== */

.article-detail-wrap {
  max-width: 860px;
  margin: 3rem auto;
  background: var(--deep-sea-card);
  border: 1px solid rgba(56, 189, 248, 0.15);
  border-radius: var(--radius-lg);
  padding: 3rem 2.5rem;
  box-shadow: var(--shadow-subtle);
}

.article-header {
  margin-bottom: 2.5rem;
  padding-bottom: 1.75rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.article-category {
  color: var(--sky-blue-light);
  font-size: 0.88rem;
  font-weight: 600;
  text-transform: uppercase;
  margin-bottom: 0.5rem;
}

.article-h1 {
  font-size: clamp(1.8rem, 3.5vw, 2.3rem);
  font-weight: 800;
  color: #fff;
  line-height: 1.35;
  margin-bottom: 1rem;
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  color: var(--text-dim);
  font-size: 0.88rem;
  flex-wrap: wrap;
}

.article-content {
  font-size: 1.05rem;
  line-height: 1.85;
  color: #e2e8f0;
}

.article-content h2 {
  font-size: 1.55rem;
  font-weight: 700;
  color: #fff;
  margin: 2.25rem 0 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid rgba(56, 189, 248, 0.2);
}

.article-content h3 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--glacier-border);
  margin: 1.75rem 0 0.75rem;
}

.article-content h4 {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--silver-text);
  margin: 1.25rem 0 0.5rem;
}

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

.article-content ul, .article-content ol {
  margin: 1rem 0 1.5rem 1.75rem;
}

.article-content li {
  margin-bottom: 0.5rem;
}

.article-callout {
  padding: 1.25rem 1.5rem;
  border-radius: var(--radius-md);
  margin: 1.75rem 0;
  font-size: 0.98rem;
  line-height: 1.75;
}

.callout-note {
  background: rgba(2, 132, 199, 0.12);
  border-left: 4px solid var(--sky-blue-light);
  color: #e0f2fe;
}

.callout-warning {
  background: rgba(245, 158, 11, 0.12);
  border-left: 4px solid var(--accent-gold);
  color: #fef3c7;
}

.callout-important {
  background: rgba(16, 185, 129, 0.12);
  border-left: 4px solid var(--success-color);
  color: #d1fae5;
}

/* 响应式表格封装 */
.table-responsive {
  width: 100%;
  overflow-x: auto;
  margin: 1.75rem 0;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(255, 255, 255, 0.1);
  -webkit-overflow-scrolling: touch;
}

table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 0.92rem;
  min-width: 500px;
}

th {
  background: var(--deep-sea-surface);
  color: #fff;
  padding: 0.85rem 1rem;
  font-weight: 600;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

td {
  padding: 0.85rem 1rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
  color: var(--text-muted);
}

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

/* 关联文章与底部推荐 */
.article-related {
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.related-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 1.25rem;
}

.related-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.25rem;
}

/* ===================================================================
   响应式断点适配规范 (Tablet & Mobile Responsiveness)
   =================================================================== */

@media (max-width: 1024px) {
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .articles-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .reviews-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .plans-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .nav-desktop {
    display: none;
  }
  .mobile-menu-toggle {
    display: flex;
  }
  .features-grid {
    grid-template-columns: 1fr;
  }
  .articles-grid {
    grid-template-columns: 1fr;
  }
  .plans-grid {
    grid-template-columns: 1fr;
  }
  .reviews-grid {
    grid-template-columns: 1fr;
  }
  .plan-dimensions-grid {
    grid-template-columns: 1fr;
  }
  .related-grid {
    grid-template-columns: 1fr;
  }
  .hero-section {
    padding: 3rem 0 2rem;
  }
  .staircase-visual {
    height: 90px;
    width: 200px;
  }
  .article-detail-wrap {
    padding: 2rem 1.25rem;
    margin: 1.5rem auto;
  }
}

@media (max-width: 430px) {
  .container {
    padding: 0 1rem;
  }
  .hero-title {
    font-size: 1.85rem;
  }
  .hero-manifesto {
    font-size: 0.98rem;
  }
  .btn {
    width: 100%;
    min-height: 48px;
  }
  .hero-actions {
    flex-direction: column;
    width: 100%;
  }
  .hero-actions .btn {
    width: 100%;
  }
  .article-h1 {
    font-size: 1.6rem;
  }
  .staircase-visual {
    height: 70px;
    width: 160px;
  }
}