/* ==========================================================================
   寰宇云官网 - 核心视觉与自适应样式表 (Pure Native CSS)
   主题风格: 深邃黑曜星云紫 (Deep Obsidian Nebula Purple)
   特性: 无外部依赖、秒开性能、无障碍高对比度 (>=4.5:1)、移动端友好 (>=44px触控)
   ========================================================================== */

:root {
  --primary: #9333ea;              /* 浓郁皇家星云紫 */
  --primary-hover: #7e22ce;
  --primary-light: rgba(147, 51, 234, 0.2);
  --accent: #38bdf8;               /* 极速深空青 */
  --accent-glow: rgba(147, 51, 234, 0.45);
  --dark-bg: #05010b;              /* 极夜黑曜底色 */
  --card-bg: rgba(16, 6, 32, 0.9);  /* 浓郁深邃星云紫晶质感 */
  --card-border: rgba(147, 51, 234, 0.28);
  --card-border-hover: rgba(192, 132, 252, 0.6);
  --text-main: #f8fafc;
  --text-muted: #a78bfa;
  --text-secondary: #cbd5e1;
  --text-dark: #ffffff;            /* 纯白主标题色 */
  --bg-light: #080314;             /* 深度沉浸星云紫背景色 */
  --bg-subtle: #0d041e;            /* 浓郁次级星云深紫 */
  --border-light: rgba(147, 51, 234, 0.22);
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --shadow-sm: 0 2px 6px rgba(0, 0, 0, 0.45);
  --shadow-md: 0 8px 18px -2px rgba(5, 1, 15, 0.8), 0 0 16px rgba(126, 34, 206, 0.18);
  --shadow-lg: 0 16px 36px -4px rgba(4, 1, 12, 0.85), 0 0 30px rgba(126, 34, 206, 0.3);
  --shadow-neon: 0 0 25px rgba(147, 51, 234, 0.45);
  --header-height: 72px;
  --container-max: 1200px;
}

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

html {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  line-height: 1.6;
  color: var(--text-secondary);
  background-color: var(--bg-light);
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background-color: #080314;
  /* 更深邃更浓郁的黑曜星云紫多层弥散光晕 */
  background-image: 
    radial-gradient(ellipse 90% 65% at 50% -12%, rgba(107, 33, 168, 0.45) 0%, transparent 65%),
    radial-gradient(circle at 12% 35%, rgba(88, 28, 135, 0.32) 0%, transparent 48%),
    radial-gradient(circle at 88% 65%, rgba(76, 29, 149, 0.28) 0%, transparent 45%),
    radial-gradient(ellipse 75% 55% at 50% 100%, rgba(59, 7, 100, 0.42) 0%, transparent 70%);
  background-attachment: fixed;
}

/* 焦点与无障碍跳步链接 */
:focus-visible {
  outline: 3px solid var(--primary);
  outline-offset: 2px;
}

.skip-link {
  position: absolute;
  top: -999px;
  left: 1rem;
  background: var(--primary);
  color: #fff;
  padding: 0.5rem 1rem;
  z-index: 9999;
  border-radius: var(--radius-sm);
  text-decoration: none;
  font-weight: 600;
}

.skip-link:focus {
  top: 1rem;
}

/* 锚点防遮挡 */
[id] {
  scroll-margin-top: calc(var(--header-height) + 1.5rem);
}

/* 基础版心容器 */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: 1.25rem;
  padding-right: 1.25rem;
}

/* 顶部导航栏 (深邃黑曜星云紫半透明毛玻璃) */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: rgba(8, 3, 18, 0.92);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border-light);
  height: var(--header-height);
  display: flex;
  align-items: center;
}

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

.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  text-decoration: none;
  color: #ffffff;
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: -0.5px;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.brand-logo:hover {
  opacity: 0.92;
  transform: translateY(-1px);
}

.brand-icon {
  width: 36px;
  height: 36px;
  flex-shrink: 0;
  filter: drop-shadow(0 2px 8px rgba(147, 51, 234, 0.5));
  transition: transform 0.3s ease;
}

.brand-logo:hover .brand-icon {
  transform: rotate(6deg) scale(1.05);
}

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

.nav-links {
  display: flex;
  list-style: none;
  gap: 1.25rem;
  align-items: center;
}

.nav-link {
  text-decoration: none;
  color: #cbd5e1;
  font-size: 0.95rem;
  font-weight: 500;
  padding: 0.5rem 0.25rem;
  transition: color 0.2s ease;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
}

.nav-link:hover, .nav-link.active {
  color: #c084fc;
}

.nav-badge {
  background-color: rgba(126, 34, 206, 0.28);
  color: #e9d5ff;
  border: 1px solid rgba(147, 51, 234, 0.4);
  font-size: 0.75rem;
  padding: 2px 7px;
  border-radius: 999px;
  margin-left: 4px;
  font-weight: 600;
}

/* CTA 按钮系统 (保底 44x44px 触控区) */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  min-width: 44px;
  padding: 0.65rem 1.4rem;
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
  cursor: pointer;
  border: 1px solid transparent;
  transition: all 0.2s ease;
  white-space: nowrap;
}

.btn-primary {
  background: linear-gradient(135deg, #9333ea 0%, #7e22ce 50%, #581c87 100%);
  color: #ffffff;
  box-shadow: 0 3px 14px rgba(126, 34, 206, 0.45);
  border: 1px solid rgba(255, 255, 255, 0.18);
}

.btn-primary:hover {
  background: linear-gradient(135deg, #a855f7 0%, #9333ea 50%, #6b21a8 100%);
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(126, 34, 206, 0.55);
}

.btn-outline {
  background-color: rgba(147, 51, 234, 0.12);
  color: #f8fafc;
  border-color: rgba(147, 51, 234, 0.45);
}

.btn-outline:hover {
  background-color: rgba(147, 51, 234, 0.25);
  border-color: #c084fc;
  color: #ffffff;
}

.btn-lg {
  padding: 0.85rem 1.85rem;
  font-size: 1.05rem;
  min-height: 50px;
}

/* 主视觉区 (Hero Section) */
.hero-section {
  padding: 4.5rem 0 3.75rem;
  background: transparent;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.4rem 1.15rem;
  background-color: rgba(88, 28, 135, 0.35);
  border: 1px solid rgba(147, 51, 234, 0.45);
  color: #f3e8ff;
  border-radius: 999px;
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 1.5rem;
  box-shadow: 0 0 18px rgba(126, 34, 206, 0.3);
}

.hero-title {
  font-size: clamp(1.85rem, 4.5vw, 3.25rem);
  font-weight: 800;
  line-height: 1.25;
  color: #ffffff;
  letter-spacing: -0.02em;
  margin-bottom: 1.35rem;
}

.text-gradient {
  background: linear-gradient(135deg, #ffffff 0%, #d8b4fe 40%, #a855f7 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-intro {
  max-width: 780px;
  margin: 0 auto 2.25rem;
  font-size: clamp(1rem, 2vw, 1.15rem);
  color: #cbd5e1;
  line-height: 1.75;
}

.hero-cta-group {
  display: flex;
  gap: 1rem;
  justify-content: center;
  align-items: center;
  flex-wrap: wrap;
  margin-bottom: 2.5rem;
}

.hero-tags {
  display: flex;
  gap: 1.5rem;
  justify-content: center;
  flex-wrap: wrap;
  color: #c084fc;
  font-size: 0.875rem;
}

.hero-tag-item {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}

/* 区块公用标题排版 */
.section {
  padding: 4.5rem 0;
}

.section-alt {
  background-color: rgba(12, 4, 25, 0.7);
}

.section-header {
  text-align: center;
  max-width: 680px;
  margin: 0 auto 3rem;
}

.section-tag {
  color: #c084fc;
  font-weight: 700;
  font-size: 0.85rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: 0.5rem;
  display: block;
}

.section-title {
  font-size: clamp(1.6rem, 3.2vw, 2.35rem);
  color: #ffffff;
  font-weight: 800;
  line-height: 1.25;
  margin-bottom: 0.85rem;
}

.section-desc {
  color: #94a3b8;
  font-size: 1rem;
  line-height: 1.65;
}

/* 核心优势卡片 (3 Cards) */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.75rem;
}

.feature-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-lg);
  padding: 2rem 1.5rem;
  transition: all 0.3s ease;
  position: relative;
  display: flex;
  flex-direction: column;
  backdrop-filter: blur(10px);
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--card-border-hover);
}

.feature-icon-box {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-md);
  background: rgba(126, 34, 206, 0.25);
  border: 1px solid rgba(147, 51, 234, 0.4);
  color: #e9d5ff;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.25rem;
  flex-shrink: 0;
}

.feature-icon-box svg {
  width: 28px;
  height: 28px;
}

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

.feature-text {
  color: #cbd5e1;
  font-size: 0.95rem;
  line-height: 1.65;
}

/* 套餐价格对比表 (保留标准表格语义) */
.pricing-table-wrapper {
  overflow-x: auto;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  border: 1px solid var(--card-border);
  background: var(--card-bg);
  backdrop-filter: blur(10px);
  margin-bottom: 2rem;
  -webkit-overflow-scrolling: touch;
}

.pricing-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  min-width: 640px;
}

.pricing-table caption {
  padding: 1rem;
  font-size: 0.95rem;
  color: #94a3b8;
  caption-side: bottom;
  text-align: center;
}

.pricing-table th,
.pricing-table td {
  padding: 1.15rem 1.25rem;
  border-bottom: 1px solid rgba(147, 51, 234, 0.16);
  color: #e2e8f0;
}

.pricing-table thead th {
  background-color: rgba(30, 11, 60, 0.9);
  color: #f8fafc;
  font-weight: 700;
  font-size: 0.95rem;
  border-bottom: 1px solid rgba(147, 51, 234, 0.3);
}

.pricing-table tbody tr:hover {
  background-color: rgba(42, 16, 85, 0.5);
}

.plan-name {
  font-weight: 700;
  color: #ffffff;
  font-size: 1.05rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.plan-badge {
  font-size: 0.7rem;
  padding: 2px 8px;
  border-radius: 999px;
  background-color: rgba(126, 34, 206, 0.35);
  color: #f3e8ff;
  border: 1px solid rgba(147, 51, 234, 0.45);
  font-weight: 600;
}

.plan-price {
  font-size: 1.35rem;
  font-weight: 800;
  color: #c084fc;
}

.plan-price span {
  font-size: 0.85rem;
  font-weight: 500;
  color: #94a3b8;
}

/* 流媒体与 AI 支持图卡 */
.media-ai-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2rem;
}

.media-ai-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-lg);
  padding: 2rem;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  backdrop-filter: blur(10px);
}

.media-ai-header {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.media-ai-badge {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  background: rgba(126, 34, 206, 0.28);
  border: 1px solid rgba(147, 51, 234, 0.4);
  color: #e9d5ff;
  display: flex;
  align-items: center;
  justify-content: center;
}

.media-ai-title {
  font-size: 1.2rem;
  font-weight: 700;
  color: #ffffff;
}

.media-ai-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
  list-style: none;
}

.media-ai-item {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.4rem 0.85rem;
  background-color: rgba(42, 16, 85, 0.55);
  border: 1px solid rgba(147, 51, 234, 0.25);
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 600;
  color: #f1f5f9;
}

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

.review-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  backdrop-filter: blur(10px);
}

.review-stars {
  color: #f59e0b;
  font-size: 1rem;
  margin-bottom: 0.75rem;
}

.review-comment {
  color: #cbd5e1;
  font-size: 0.95rem;
  line-height: 1.65;
  margin-bottom: 1rem;
  flex-grow: 1;
}

.review-user {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  border-top: 1px solid rgba(147, 51, 234, 0.2);
  padding-top: 0.75rem;
}

.user-avatar {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  background-color: rgba(126, 34, 206, 0.3);
  border: 1px solid rgba(147, 51, 234, 0.4);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  color: #f3e8ff;
  font-size: 0.85rem;
}

.user-meta-name {
  font-weight: 600;
  color: #ffffff;
  font-size: 0.9rem;
}

.user-meta-role {
  color: #94a3b8;
  font-size: 0.75rem;
}

/* FAQ 常见问题解答 (原生 details / summary 无JS依赖，默认展开 open) */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  max-width: 860px;
  margin: 0 auto;
}

.faq-item {
  border: 1px solid var(--card-border);
  border-radius: var(--radius-md);
  background-color: var(--card-bg);
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
  overflow: hidden;
  backdrop-filter: blur(10px);
}

.faq-item[open] {
  border-color: rgba(192, 132, 252, 0.55);
  box-shadow: 0 4px 18px rgba(126, 34, 206, 0.25);
}

.faq-question {
  padding: 1.15rem 1.25rem;
  font-weight: 700;
  font-size: 1.05rem;
  color: #ffffff;
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  user-select: none;
  min-height: 44px;
}

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

.faq-question::after {
  content: "+";
  font-size: 1.4rem;
  font-weight: 400;
  color: #c084fc;
  line-height: 1;
  transition: transform 0.2s ease;
  margin-left: 0.5rem;
}

.faq-item[open] .faq-question::after {
  content: "−";
}

.faq-answer {
  padding: 0 1.25rem 1.25rem;
  color: #cbd5e1;
  font-size: 0.95rem;
  line-height: 1.7;
  border-top: 1px solid transparent;
}

.faq-answer a {
  color: #38bdf8;
  text-decoration: underline;
  font-weight: 600;
}

/* 页脚 (规范严格只保留 4 个核心入口) */
.site-footer {
  background-color: #04010a;
  color: #94a3b8;
  padding: 3.5rem 0 2rem;
  margin-top: auto;
  border-top: 1px solid rgba(147, 51, 234, 0.25);
}

.footer-nav-list {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 2.5rem;
  list-style: none;
  margin-bottom: 2rem;
  flex-wrap: wrap;
}

.footer-nav-link {
  color: #e2e8f0;
  text-decoration: none;
  font-size: 1rem;
  font-weight: 600;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  padding: 0.25rem 0.5rem;
  transition: color 0.2s ease;
}

.footer-nav-link:hover {
  color: #c084fc;
}

.footer-bottom {
  text-align: center;
  font-size: 0.85rem;
  color: #64748b;
  border-top: 1px solid rgba(147, 51, 234, 0.18);
  padding-top: 1.5rem;
}

/* ==========================================================================
   文章与科普页面专用样式
   ========================================================================== */
.article-header {
  padding: 3rem 0 2rem;
  background-color: rgba(14, 5, 28, 0.8);
  border-bottom: 1px solid var(--border-light);
}

.breadcrumb {
  display: flex;
  list-style: none;
  gap: 0.5rem;
  align-items: center;
  font-size: 0.875rem;
  color: #c084fc;
  margin-bottom: 1rem;
}

.breadcrumb a {
  color: #cbd5e1;
  text-decoration: none;
}

.breadcrumb a:hover {
  color: #e9d5ff;
}

.article-title {
  font-size: clamp(1.6rem, 3.5vw, 2.3rem);
  font-weight: 800;
  color: #ffffff;
  line-height: 1.3;
  margin-bottom: 0.75rem;
}

.article-meta {
  display: flex;
  gap: 1.25rem;
  color: #a78bfa;
  font-size: 0.875rem;
  flex-wrap: wrap;
}

.article-body {
  padding: 3rem 0;
  max-width: 820px;
  margin: 0 auto;
}

.article-content {
  font-size: 1.05rem;
  line-height: 1.8;
  color: #cbd5e1;
}

.article-content h2 {
  font-size: 1.5rem;
  color: #ffffff;
  font-weight: 700;
  margin: 2rem 0 1rem;
  padding-bottom: 0.4rem;
  border-bottom: 2px solid rgba(147, 51, 234, 0.3);
}

.article-content h3 {
  font-size: 1.25rem;
  color: #f1f5f9;
  font-weight: 700;
  margin: 1.5rem 0 0.75rem;
}

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

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

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

.article-content a {
  color: #38bdf8;
  text-decoration: underline;
  font-weight: 600;
}

.article-callout {
  background-color: rgba(59, 7, 100, 0.45);
  border-left: 4px solid #9333ea;
  padding: 1.25rem;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  margin: 1.5rem 0;
  color: #f1f5f9;
}

.article-callout p {
  margin-bottom: 0;
}

/* 知识中心卡片网格 */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.75rem;
  margin-bottom: 3.5rem;
}

.article-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: all 0.25s ease;
  backdrop-filter: blur(10px);
}

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

.article-card-tag {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  color: #f3e8ff;
  background-color: rgba(126, 34, 206, 0.35);
  border: 1px solid rgba(147, 51, 234, 0.45);
  padding: 2px 8px;
  border-radius: 4px;
  margin-bottom: 0.75rem;
  width: fit-content;
}

.article-card-title {
  font-size: 1.15rem;
  font-weight: 700;
  line-height: 1.4;
  margin-bottom: 0.75rem;
}

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

.article-card-title a:hover {
  color: #c084fc;
}

.article-card-excerpt {
  color: #94a3b8;
  font-size: 0.9rem;
  line-height: 1.6;
  margin-bottom: 1.25rem;
  flex-grow: 1;
}

.article-card-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.8rem;
  color: #c084fc;
  border-top: 1px solid rgba(147, 51, 234, 0.18);
  padding-top: 0.75rem;
}

/* ==========================================================================
   响应式媒体查询 (@media)
   测试宽度标准: 360px, 390px, 768px, 1440px
   ========================================================================== */

@media (max-width: 992px) {
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .articles-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .reviews-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  :root {
    --header-height: 64px;
  }
  
  .header-inner {
    flex-wrap: wrap;
    gap: 0.75rem;
  }
  
  .main-nav {
    display: none; /* 移动端精简头部，确保秒开与紧凑 */
  }
  
  .features-grid,
  .media-ai-grid,
  .articles-grid,
  .reviews-grid {
    grid-template-columns: 1fr;
  }
  
  .hero-section {
    padding: 3rem 0 2rem;
  }
  
  .hero-cta-group {
    flex-direction: column;
    width: 100%;
  }
  
  .hero-cta-group .btn {
    width: 100%;
  }
  
  .footer-nav-list {
    flex-direction: column;
    gap: 1rem;
  }
  
  .pricing-table th,
  .pricing-table td {
    padding: 0.85rem 0.75rem;
    font-size: 0.875rem;
  }
}

@media (max-width: 390px) {
  .hero-title {
    font-size: 1.7rem;
  }
  .section-title {
    font-size: 1.45rem;
  }
  .container {
    padding-left: 1rem;
    padding-right: 1rem;
  }
}

/* 动效降级保障 */
@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;
  }
}