/* ==============================================================================
   吹雪云 (cxy.lat) - 官方推广落地页样式表
   版本: 1.0.0
   设计语言: 现代极简 / 亮蓝科技风 / 玻璃拟态 / 响应式适配
   ============================================================================== */

:root {
  /* 主题色系 */
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --primary-light: #eff6ff;
  --primary-gradient: linear-gradient(135deg, #2563eb 0%, #3b82f6 100%);
  --primary-gradient-hover: linear-gradient(135deg, #1d4ed8 0%, #2563eb 100%);
  
  /* 辅助与强调色 */
  --accent: #0284c7;
  --accent-light: #f0f9ff;
  --success: #10b981;
  --warning: #f59e0b;
  
  /* 中性色系统 (Light Theme) */
  --bg-page: #f8fafc;
  --bg-card: rgba(255, 255, 255, 0.9);
  --bg-card-hover: #ffffff;
  --bg-subtle: #f1f5f9;
  
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #64748b;
  --text-inverse: #ffffff;
  
  --border-color: #e2e8f0;
  --border-light: rgba(226, 232, 240, 0.8);
  --border-focus: #3b82f6;
  
  /* 阴影层级 */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 10px 25px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.04);
  --shadow-xl: 0 20px 40px -10px rgba(0, 0, 0, 0.12), 0 1px 3px 0 rgba(0, 0, 0, 0.05);
  --shadow-btn: 0 4px 14px 0 rgba(37, 99, 235, 0.35);
  --shadow-btn-hover: 0 6px 20px 0 rgba(37, 99, 235, 0.45);
  
  /* 尺寸与圆角 */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;
  
  --container-max: 1160px;
  --transition-fast: 0.18s ease;
  --transition-base: 0.28s cubic-bezier(0.16, 1, 0.3, 1);
}

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

html {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
  color: var(--text-primary);
  background-color: var(--bg-page);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  scroll-behavior: smooth;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  background-image: 
    radial-gradient(at 10% 10%, rgba(37, 99, 235, 0.04) 0px, transparent 50%),
    radial-gradient(at 90% 90%, rgba(2, 132, 199, 0.04) 0px, transparent 50%);
  background-attachment: fixed;
}

a {
  color: var(--primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--primary-hover);
}

img, svg {
  vertical-align: middle;
}

/* 容器通用类 */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: 20px;
  padding-right: 20px;
}

/* ==============================================================================
   页眉 Header & Navigation
   ============================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  transition: all var(--transition-fast);
}

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

.brand-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 20px;
  font-weight: 700;
  color: var(--text-primary);
  text-decoration: none;
}

.brand-logo:hover {
  color: var(--primary);
}

.logo-icon {
  width: 36px;
  height: 36px;
  background: var(--primary-gradient);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #ffffff;
  box-shadow: 0 4px 10px rgba(37, 99, 235, 0.25);
}

.logo-badge {
  font-size: 11px;
  font-weight: 500;
  padding: 2px 7px;
  border-radius: var(--radius-full);
  background: var(--primary-light);
  color: var(--primary);
  border: 1px solid rgba(37, 99, 235, 0.2);
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 28px;
  list-style: none;
}

.nav-link {
  font-size: 15px;
  font-weight: 500;
  color: var(--text-secondary);
  transition: color var(--transition-fast);
  padding: 6px 2px;
  position: relative;
}

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

.nav-link.active::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--primary);
  border-radius: 2px;
}

.header-cta {
  display: flex;
  align-items: center;
  gap: 12px;
}

/* ==============================================================================
   按钮规范 (符合用户规范要求：大圆角、亮蓝色渐变、清晰悬停与焦点反馈)
   ============================================================================== */
.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 26px;
  font-size: 15px;
  font-weight: 600;
  color: var(--text-inverse) !important;
  background: var(--primary-gradient);
  border: none;
  border-radius: var(--radius-full);
  box-shadow: var(--shadow-btn);
  cursor: pointer;
  text-decoration: none;
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}

.btn-primary:hover {
  background: var(--primary-gradient-hover);
  transform: translateY(-2px);
  box-shadow: var(--shadow-btn-hover);
}

.btn-primary:active {
  transform: translateY(0);
}

.btn-primary:focus-visible {
  outline: 3px solid rgba(37, 99, 235, 0.5);
  outline-offset: 3px;
}

.btn-primary.btn-large {
  padding: 14px 34px;
  font-size: 16px;
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  font-size: 15px;
  font-weight: 600;
  color: var(--text-secondary);
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  box-shadow: var(--shadow-sm);
  cursor: pointer;
  text-decoration: none;
  transition: all var(--transition-fast);
}

.btn-secondary:hover {
  color: var(--primary);
  border-color: var(--primary);
  background: var(--primary-light);
  transform: translateY(-1px);
}

.btn-secondary:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

/* ==============================================================================
   主视觉区 Hero Section
   ============================================================================== */
.hero-section {
  padding: 64px 0 48px;
  text-align: center;
}

.hero-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  background: var(--primary-light);
  color: var(--primary);
  border-radius: var(--radius-full);
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 24px;
  border: 1px solid rgba(37, 99, 235, 0.15);
}

.hero-tag-pulse {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--primary);
  box-shadow: 0 0 0 rgba(37, 99, 235, 0.6);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0% {
    box-shadow: 0 0 0 0 rgba(37, 99, 235, 0.6);
  }
  70% {
    box-shadow: 0 0 0 8px rgba(37, 99, 235, 0);
  }
  100% {
    box-shadow: 0 0 0 0 rgba(37, 99, 235, 0);
  }
}

.hero-title {
  font-size: 40px;
  line-height: 1.25;
  font-weight: 800;
  color: var(--text-primary);
  margin-bottom: 18px;
  letter-spacing: -0.02em;
}

.hero-title-highlight {
  background: var(--primary-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-desc {
  font-size: 17px;
  line-height: 1.7;
  color: var(--text-secondary);
  max-width: 680px;
  margin: 0 auto 32px;
}

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

.hero-note {
  font-size: 13px;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
}

/* ==============================================================================
   核心信息卡片 Section (Core Information)
   ============================================================================== */
.section {
  padding: 56px 0;
}

.section-header {
  text-align: center;
  max-width: 640px;
  margin: 0 auto 44px;
}

.section-label {
  font-size: 13px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--primary);
  margin-bottom: 8px;
}

.section-title {
  font-size: 30px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 12px;
  letter-spacing: -0.01em;
}

.section-desc {
  font-size: 15px;
  color: var(--text-secondary);
}

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

.info-card {
  background: var(--bg-card);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 32px 26px;
  transition: all var(--transition-base);
  display: flex;
  flex-direction: column;
}

.info-card:hover {
  background: var(--bg-card-hover);
  border-color: rgba(37, 99, 235, 0.3);
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.card-icon-wrap {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-md);
  background: var(--primary-light);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
}

.card-title {
  font-size: 19px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 12px;
}

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

.card-list {
  list-style: none;
  font-size: 13.5px;
  color: var(--text-secondary);
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding-top: 16px;
  border-top: 1px solid var(--border-color);
}

.card-list-item {
  display: flex;
  align-items: flex-start;
  gap: 8px;
}

.card-list-icon {
  flex-shrink: 0;
  margin-top: 3px;
  color: var(--success);
}

/* ==============================================================================
   套餐指引板块 (Plans / Packages)
   ============================================================================== */
.plans-section {
  background: linear-gradient(180deg, rgba(241, 245, 249, 0.6) 0%, rgba(248, 250, 252, 0.8) 100%);
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
}

.plans-box {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  padding: 44px 36px;
  box-shadow: var(--shadow-md);
}

.plans-notice-card {
  background: #fffbeb;
  border: 1px solid #fef3c7;
  border-left: 4px solid var(--warning);
  border-radius: var(--radius-sm);
  padding: 16px 20px;
  margin-bottom: 32px;
  display: flex;
  align-items: flex-start;
  gap: 12px;
  font-size: 14px;
  color: #92400e;
}

.plans-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-bottom: 36px;
}

.plan-item {
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 24px;
  background: var(--bg-page);
  display: flex;
  flex-direction: column;
  transition: all var(--transition-fast);
}

.plan-item:hover {
  border-color: var(--primary);
  background: #ffffff;
  box-shadow: var(--shadow-sm);
}

.plan-category {
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--primary);
  margin-bottom: 6px;
}

.plan-name {
  font-size: 18px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 10px;
}

.plan-desc {
  font-size: 13.5px;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 16px;
}

.plan-meta {
  margin-top: auto;
  font-size: 13px;
  font-weight: 600;
  color: var(--text-muted);
}

.plans-cta-wrapper {
  text-align: center;
  padding-top: 12px;
}

/* ==============================================================================
   常见问题 FAQ
   ============================================================================== */
.faq-grid {
  max-width: 820px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.faq-card {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 24px 28px;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-fast);
}

.faq-card:hover {
  border-color: rgba(37, 99, 235, 0.4);
}

.faq-question {
  font-size: 16.5px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.faq-question-icon {
  color: var(--primary);
  flex-shrink: 0;
}

.faq-answer {
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--text-secondary);
  padding-left: 28px;
}

/* ==============================================================================
   页脚 Footer
   ============================================================================== */
.site-footer {
  margin-top: auto;
  background: #0f172a;
  color: #94a3b8;
  padding: 56px 0 32px;
  border-top: 1px solid #1e293b;
}

.footer-top {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 48px;
  margin-bottom: 40px;
}

.footer-brand-title {
  color: #ffffff;
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.footer-desc {
  font-size: 13.5px;
  line-height: 1.7;
  color: #94a3b8;
  max-width: 420px;
}

.footer-col-title {
  color: #ffffff;
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 16px;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-links a {
  color: #94a3b8;
  font-size: 14px;
  transition: color var(--transition-fast);
}

.footer-links a:hover {
  color: #ffffff;
}

.footer-bottom {
  padding-top: 28px;
  border-top: 1px solid #1e293b;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 13px;
  flex-wrap: wrap;
  gap: 16px;
}

.footer-disclaimer {
  font-size: 12px;
  color: #64748b;
  line-height: 1.6;
}

/* ==============================================================================
   弹窗与遮罩层规范 (二、弹窗与遮罩层)
   1. 页面加载后延迟约 300ms 淡入显示公告弹窗。
   2. 遮罩覆盖全屏，使用：
      backdrop-filter: blur(8px);
      background: rgba(0, 0, 0, 0.45);
   3. 弹窗水平、垂直居中，白色背景、16px 圆角及柔和阴影，最大宽度约 440px，移动端左右保留合理间距。
   4. 右上角提供“✕”关闭按钮，点击后展示底层页面；点击遮罩空白处或按 Escape 也可关闭。
   5. 标题：“访问提示”。
   6. 正文：“欢迎访问吹雪云推广介绍页。如需了解服务详情、当前套餐和可用情况，请前往服务商页面查看。具体服务内容、价格及公告以服务商实际公布的信息为准。”
   7. 主按钮文案：“前往服务商查看”。
   8. 按钮使用大圆角和亮蓝色渐变，提供清晰的悬停与键盘焦点反馈。
   9. 尊重 prefers-reduced-motion。JavaScript 不可用时不显示阻挡页面的遮罩，底层推广链接仍正常使用。
   ============================================================================== */
.modal-overlay {
  /* JS加载前严格默认隐藏，避免 JS 不可用时阻挡页面 */
  display: none;
  position: fixed;
  inset: 0;
  z-index: 1000;
  background: rgba(0, 0, 0, 0.45);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  align-items: center;
  justify-content: center;
  padding: 16px;
  opacity: 0;
  transition: opacity 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

/* 当 JS 添加 is-active 类时激活 */
.modal-overlay.is-active {
  display: flex;
  opacity: 1;
}

.modal-dialog {
  background: #ffffff;
  border-radius: 16px;
  box-shadow: 0 20px 45px -10px rgba(0, 0, 0, 0.22), 0 0 0 1px rgba(0, 0, 0, 0.05);
  max-width: 440px;
  width: 100%;
  position: relative;
  padding: 32px 28px 28px;
  text-align: center;
  transform: scale(0.94) translateY(8px);
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

.modal-overlay.is-active .modal-dialog {
  transform: scale(1) translateY(0);
}

.modal-close-btn {
  position: absolute;
  top: 14px;
  right: 14px;
  width: 34px;
  height: 34px;
  border: none;
  background: #f1f5f9;
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--text-muted);
  font-size: 16px;
  transition: all var(--transition-fast);
}

.modal-close-btn:hover {
  background: #e2e8f0;
  color: var(--text-primary);
  transform: rotate(90deg);
}

.modal-close-btn:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

.modal-icon-badge {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-full);
  background: var(--primary-light);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 18px;
}

.modal-title {
  font-size: 21px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 14px;
  letter-spacing: -0.01em;
}

.modal-body {
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--text-secondary);
  margin-bottom: 26px;
  text-align: left;
  background: var(--bg-subtle);
  padding: 16px 18px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
}

.modal-actions {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.modal-btn-promo {
  width: 100%;
  padding: 13px 20px;
  font-size: 15.5px;
  font-weight: 600;
  border-radius: var(--radius-full);
  background: var(--primary-gradient);
  color: #ffffff !important;
  box-shadow: var(--shadow-btn);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  text-decoration: none;
  border: none;
  cursor: pointer;
  transition: all var(--transition-base);
}

.modal-btn-promo:hover {
  background: var(--primary-gradient-hover);
  transform: translateY(-2px);
  box-shadow: var(--shadow-btn-hover);
}

.modal-btn-promo:focus-visible {
  outline: 3px solid rgba(37, 99, 235, 0.5);
  outline-offset: 2px;
}

/* ==============================================================================
   独立文章页/关于/条款通用页面排版 (about.html, terms.html, privacy.html, sitemap.html)
   ============================================================================== */
.doc-header {
  padding: 44px 0 28px;
  background: #ffffff;
  border-bottom: 1px solid var(--border-color);
}

.doc-breadcrumbs {
  font-size: 13.5px;
  color: var(--text-muted);
  margin-bottom: 12px;
}

.doc-breadcrumbs a {
  color: var(--text-secondary);
}

.doc-breadcrumbs a:hover {
  color: var(--primary);
}

.doc-title {
  font-size: 28px;
  font-weight: 800;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.doc-meta {
  font-size: 13px;
  color: var(--text-muted);
}

.doc-content {
  padding: 48px 0 64px;
}

.doc-card {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 36px 40px;
  box-shadow: var(--shadow-sm);
  max-width: 860px;
  margin: 0 auto;
}

.doc-section {
  margin-bottom: 32px;
}

.doc-section:last-child {
  margin-bottom: 0;
}

.doc-section-title {
  font-size: 18px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-color);
}

.doc-text {
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--text-secondary);
  margin-bottom: 14px;
}

.doc-list {
  padding-left: 20px;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--text-secondary);
  margin-bottom: 14px;
}

/* 网站地图专用排版 */
.sitemap-group {
  margin-bottom: 28px;
}

.sitemap-group-title {
  font-size: 17px;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.sitemap-links-list {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
}

.sitemap-link-card {
  background: var(--bg-page);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 14px 18px;
  display: block;
  transition: all var(--transition-fast);
}

.sitemap-link-card:hover {
  background: #ffffff;
  border-color: var(--primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

.sitemap-link-title {
  font-size: 15px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 4px;
}

.sitemap-link-url {
  font-size: 12px;
  color: var(--text-muted);
}

/* ==============================================================================
   无障碍：尊重 prefers-reduced-motion
   ============================================================================== */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.001s !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001s !important;
    scroll-behavior: auto !important;
  }
}

/* ==============================================================================
   移动端响应式 (Responsive)
   ============================================================================== */
@media (max-width: 900px) {
  .cards-grid {
    grid-template-columns: 1fr;
    gap: 18px;
  }
  
  .plans-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }
  
  .footer-top {
    grid-template-columns: 1fr;
    gap: 32px;
  }
  
  .sitemap-links-list {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  .hero-title {
    font-size: 28px;
  }
  
  .hero-desc {
    font-size: 15px;
  }
  
  .nav-menu {
    display: none; /* 简化移动端，直观呈现内容与CTA */
  }
  
  .plans-box {
    padding: 24px 18px;
  }
  
  .modal-dialog {
    padding: 26px 20px 20px;
    border-radius: 14px;
  }
  
  .doc-card {
    padding: 24px 20px;
  }
}