/* ============================================================
   HOME PAGE STYLES — 深色系 · 纯灰度层级 · 无边框 · 无动效
   基于 GLOBAL.CSS 颜色系统（16阶视觉无偏色灰阶）
   仅保留 transform 作为交互反馈
   品牌色使用占比 < 10%
   ============================================================ */

/* ============================================================
   1. 颜色系统（继承自 GLOBAL.CSS）
   ============================================================ */
/* 注：以下变量已在 global.css 中定义，此处仅作引用说明 */
:root {
  /* 核心色（来自 global.css） */
  --color-black: #020101;
  --color-white: #fffefe;
  --color-brand: #fedc10;

  /* 16阶灰阶（global.css 提供） */
  --gray-01: #fffefe;
  --gray-02: #f3f2f2;
  --gray-03: #e6e5e5;
  --gray-04: #d8d7d7;
  --gray-05: #cbcaca;
  --gray-06: #bebdbd;
  --gray-07: #a9a8a8;
  --gray-08: #949393;
  --gray-09: #7f7e7e;
  --gray-10: #6a6969;
  --gray-11: #555454;
  --gray-12: #403f3f;
  --gray-13: #2d2c2c;
  --gray-14: #1b1a1a;
  --gray-15: #0e0d0d;
  --gray-16: #020101;

  /* 语义化映射（使用 global.css 的标准 token） */
  --bg-primary: var(--color-black);      /* 全局背景 #020101 */
  --bg-secondary: var(--gray-15);        /* 次级背景 #0e0d0d */
  --bg-card: var(--gray-14);             /* 卡片背景 #1b1a1a */
  --bg-surface: var(--gray-13);          /* 表层（用于悬停或更亮区域） #2d2c2c */
  --bg-input: var(--gray-12);            /* 输入框背景 #403f3f */

  --text-main: var(--color-white);       /* 主文本 #fffefe */
  --text-secondary: var(--gray-04);      /* 次要文本 #d8d7d7 */
  --text-muted: var(--gray-08);          /* 弱化文本 #949393 */

  /* 品牌色仅用于极少数关键按钮和高亮文字（<10%） */
  --brand-color: var(--color-brand);

  /* 尺寸与间距 */
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --gap: 20px;
  --header-h: 64px;

  /* 无任何阴影或过渡（仅保留 transform 即时变化） */
  --shadow: none;
  --shadow-hover: none;
  --transition: none;
}

/* ============================================================
   2. 全局重置
   ============================================================ */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  background-color: var(--bg-primary);
  color: var(--text-main);
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  font-weight: 400;
  line-height: 1.7;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  padding-top: 90px;
}

.container {
  max-width: 1120px;
  margin: 0 auto;
  padding: 32px 32px 48px;
  width: 100%;
  flex: 1;
}

/* ============================================================
   3. 排版（仅颜色调整，无边框）
   ============================================================ */
.section-tag {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 2.5px;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 12px;
  display: inline-block;
}

.section-title-large {
  font-size: 34px;
  font-weight: 600;
  letter-spacing: -0.5px;
  line-height: 1.2;
  margin-bottom: 12px;
  color: var(--text-main);
}

.section-sub {
  font-size: 16px;
  font-weight: 400;
  color: var(--text-secondary);
  max-width: 540px;
  line-height: 1.7;
  margin-bottom: 40px;
}

/* ============================================================
   4. 布局工具
   ============================================================ */
.grid-3col {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

/* ============================================================
   5. 导航栏（纯色背景，无边框）
   ============================================================ */
.navbar {
  position: fixed;
  top: 16px;
  left: 50%;
  transform: translateX(-50%);
  width: calc(100% - 64px);
  max-width: 1120px;
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
  padding: 12px 28px;
  background-color: var(--bg-secondary);
  border-radius: 100px;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
  text-decoration: none;
  color: inherit;
}

.nav-logo {
  height: 40px;
  width: auto;
  display: block;
}

.brand-text {
  font-size: 24px;
  font-weight: 600;
  color: var(--text-main);
  letter-spacing: -0.3px;
}

.nav-links {
  display: flex;
  gap: 28px;
  list-style: none;
  align-items: center;
  flex-shrink: 0;
}

.nav-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 14px;
  font-weight: 400;
}

.nav-links a:hover {
  color: var(--text-main);
}

.nav-cta-btn {
  background-color: var(--color-brand);
  padding: 7px 20px;
  border-radius: 100px;
  color: var(--color-black) !important;
  font-weight: 500;
  font-size: 13px;
}

.nav-cta-btn:hover {
  transform: scale(1.02);
  opacity: 0.9;
}

/* ============================================================
   6. Hero 区域
   ============================================================ */
.hero-section {
  text-align: center;
  padding: 56px 0 48px;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 5px 16px;
  border-radius: 100px;
  background-color: var(--bg-card);
  color: var(--text-secondary);
  font-size: 12px;
  font-weight: 500;
  margin-bottom: 28px;
}

.hero-badge i {
  color: var(--color-brand);
}

.hero-title {
  font-size: 52px;
  font-weight: 700;
  letter-spacing: -1.5px;
  line-height: 1.15;
  max-width: 800px;
  margin: 0 auto 20px;
  color: var(--text-main);
}

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

.hero-desc {
  font-size: 17px;
  font-weight: 400;
  color: var(--text-secondary);
  max-width: 540px;
  margin: 0 auto 36px;
  line-height: 1.7;
}

.hero-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 56px;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 28px;
  border-radius: 100px;
  background-color: var(--color-brand);
  color: var(--color-black);
  font-weight: 600;
  font-size: 14px;
  text-decoration: none;
  cursor: pointer;
}

.btn-primary:hover {
  transform: scale(1.02);
  opacity: 0.9;
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 28px;
  border-radius: 100px;
  background-color: var(--bg-card);
  color: var(--text-main);
  font-weight: 500;
  font-size: 14px;
  text-decoration: none;
}

.btn-secondary:hover {
  background-color: var(--bg-surface);
  transform: scale(1.02);
}

.stats-row {
  display: flex;
  justify-content: center;
  gap: 64px;
  background-color: var(--bg-secondary);
  border-radius: 20px;
  padding: 40px 48px;
}

.stat-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
}

.stat-number {
  font-size: 30px;
  font-weight: 700;
  color: var(--text-main);
  letter-spacing: -0.5px;
}

.stat-label {
  font-size: 12px;
  color: var(--text-muted);
  font-weight: 400;
}

/* ============================================================
   7. Trust 信任标识
   ============================================================ */
.trust-section {
  padding: 40px 0;
  text-align: center;
}

.trust-grid {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 48px;
  margin-top: 20px;
}

.trust-item {
  font-size: 13px;
  font-weight: 500;
  color: var(--text-muted);
  letter-spacing: 0.5px;
}

.trust-item:hover {
  color: var(--text-secondary);
  transform: translateY(-1px);
}

/* ============================================================
   8. Values 卡片（纯色背景，无边框）
   ============================================================ */
.section-about {
  padding: 48px 0;
}

.value-card {
  background-color: var(--bg-card);
  border-radius: 24px;
  padding: 32px 24px;
}

.value-card:hover {
  background-color: var(--bg-surface);
  transform: translateY(-2px);
}

.value-card .icon {
  font-size: 24px;
  color: var(--color-brand);
  margin-bottom: 16px;
  display: inline-block;
}

.value-card h3 {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text-main);
}

.value-card p {
  font-size: 13.5px;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ============================================================
   9. Products 产品卡片
   ============================================================ */
.section-products {
  padding: 48px 0;
}

.product-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 24px;
  margin-top: 8px;
}

.product-card {
  background-color: var(--bg-card);
  border-radius: 24px;
  padding: 32px 24px;
  display: flex;
  flex-direction: column;
  text-decoration: none;
  color: inherit;
}

.product-card:hover {
  background-color: var(--bg-surface);
  transform: translateY(-2px);
}

.product-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 20px;
}

.product-icon {
  width: 44px;
  height: 44px;
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  color: var(--text-main);
  background-color: var(--bg-secondary);
}

.product-status {
  font-size: 11px;
  font-weight: 500;
  padding: 3px 12px;
  border-radius: 100px;
  background-color: var(--bg-secondary);
  color: var(--text-secondary);
}

.product-card h3 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text-main);
}

.product-card p {
  font-size: 13.5px;
  color: var(--text-secondary);
  line-height: 1.7;
  flex: 1;
}

.product-features {
  margin: 16px 0 0;
  list-style: none;
}

.product-features li {
  font-size: 13px;
  color: var(--text-secondary);
  padding: 3px 0;
  display: flex;
  align-items: center;
  gap: 8px;
}

.product-features li i {
  color: var(--text-muted);
  font-size: 14px;
}

.product-link {
  margin-top: 20px;
  color: var(--text-main);
  font-weight: 500;
  font-size: 13.5px;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.product-link:hover {
  color: var(--color-brand);
  transform: translateX(2px);
}

/* ============================================================
   10. Metrics 指标面板
   ============================================================ */
.metrics-section {
  padding: 48px 32px;
  text-align: center;
  border-radius: 24px;
  background-color: var(--bg-secondary);
  margin: 40px 0;
}

.metrics-grid {
  display: flex;
  justify-content: center;
  gap: 80px;
  flex-wrap: wrap;
}

.metric-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
}

.metric-item .num {
  font-size: 40px;
  font-weight: 700;
  color: var(--text-main);
  letter-spacing: -1px;
}

.metric-item .label {
  font-size: 12px;
  font-weight: 500;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 1px;
}

/* ============================================================
   11. Testimonials 评价
   ============================================================ */
.section-testimonials {
  padding: 48px 0;
}

.testimonial-card {
  background-color: var(--bg-card);
  border-radius: 24px;
  padding: 32px 24px;
}

.testimonial-card:hover {
  background-color: var(--bg-surface);
  transform: translateY(-2px);
}

.testimonial-card .quote {
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--text-secondary);
  font-style: normal;
}

.testimonial-card .author {
  margin-top: 20px;
  display: flex;
  align-items: center;
  gap: 12px;
}

.testimonial-card .author .name {
  font-weight: 600;
  font-size: 13.5px;
  color: var(--text-main);
}

.testimonial-card .author .role {
  font-size: 12px;
  color: var(--text-muted);
}

/* ============================================================
   12. Blog 博客列表
   ============================================================ */
.section-blog {
  padding: 48px 0;
}

.blog-list {
  margin-top: 8px;
  background-color: var(--bg-card);
  border-radius: 24px;
  padding: 8px 24px;
}

.blog-item {
  display: flex;
  gap: 24px;
  padding: 18px 0;
  align-items: center;
  flex-wrap: wrap;
}

.blog-item:not(:last-child) {
  border-bottom: 1px solid var(--bg-secondary); /* 用背景色替代边框，视觉上仍是分隔 */
}

.blog-item .date {
  font-size: 12.5px;
  color: var(--text-muted);
  min-width: 96px;
  font-weight: 400;
}

.blog-item .title {
  color: var(--text-main);
  font-weight: 500;
  font-size: 14.5px;
  text-decoration: none;
  flex: 1;
}

.blog-item .title:hover {
  color: var(--color-brand);
}

.blog-item .tag {
  font-size: 11px;
  font-weight: 500;
  padding: 3px 10px;
  border-radius: 100px;
  background-color: var(--bg-secondary);
  color: var(--text-secondary);
}

/* ============================================================
   13. FAQ 折叠面板
   ============================================================ */
.section-faq {
  padding: 48px 0;
}

.faq-list {
  width: 100%;
}

details {
  background-color: var(--bg-card);
  border-radius: 20px;
  padding: 16px 24px;
  margin-bottom: 12px;
  cursor: pointer;
  width: 100%;
}

details:hover {
  background-color: var(--bg-surface);
}

details summary {
  font-weight: 500;
  font-size: 15px;
  color: var(--text-main);
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

details summary::-webkit-details-marker {
  display: none;
}

details summary::after {
  content: '+';
  font-family: inherit;
  color: var(--text-secondary);
  font-size: 18px;
  font-weight: 400;
}

details[open] summary::after {
  content: '-';
}

details .faq-answer {
  color: var(--text-secondary);
  padding-top: 12px;
  line-height: 1.7;
  font-size: 13.5px;
  margin-top: 12px;
  background-color: var(--bg-secondary);
  border-radius: 12px;
  padding: 16px 20px;
}

/* ============================================================
   14. Newsletter 订阅
   ============================================================ */
.newsletter-box {
  background-color: var(--bg-secondary);
  border-radius: 24px;
  padding: 48px 40px;
  text-align: center;
  margin: 40px 0;
  color: var(--text-main);
}

.newsletter-box h2 {
  font-size: 28px;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--text-main);
  letter-spacing: -0.3px;
}

.newsletter-box p {
  color: var(--text-secondary);
  font-size: 15px;
  margin-bottom: 24px;
}

.newsletter-form {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}

.newsletter-form input {
  padding: 13px 20px;
  border-radius: 100px;
  border: none;
  background-color: var(--bg-card);
  font-size: 14px;
  width: 300px;
  outline: none;
  color: var(--text-main);
}

.newsletter-form input:focus {
  background-color: var(--bg-surface);
  transform: scale(1.01);
}

.newsletter-form input::placeholder {
  color: var(--text-muted);
}

.newsletter-form .btn-primary {
  border: none;
  cursor: pointer;
}

.newsletter-privacy {
  font-size: 12px;
  color: var(--text-muted);
  margin-top: 16px;
}

/* ============================================================
   15. Footer 页脚
   ============================================================ */
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 48px;
  padding: 48px 32px 32px;
  background-color: var(--bg-secondary);
  border-radius: 24px 24px 0 0;
  margin-top: 40px;
  align-items: start;
}

.brand-col {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 12px;
}

.brand-name {
  font-size: 20px;
  font-weight: 700;
  color: var(--text-main);
  letter-spacing: -0.3px;
}

.brand-desc {
  font-size: 13.5px;
  color: var(--text-muted);
  line-height: 1.6;
  max-width: 260px;
}

.social-icons {
  display: flex;
  gap: 12px;
  margin-top: 4px;
}

.social-icons a {
  color: var(--text-secondary);
  font-size: 16px;
  text-decoration: none;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  border-radius: 50%;
  background-color: var(--bg-card);
}

.social-icons a:hover {
  background-color: var(--bg-surface);
  color: var(--text-main);
  transform: translateY(-2px);
}

.col {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 8px;
}

.col h4 {
  font-size: 12px;
  font-weight: 600;
  color: var(--text-main);
  margin-bottom: 6px;
  letter-spacing: 1px;
  text-transform: uppercase;
}

.col a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 13.5px;
  font-weight: 400;
  padding: 2px 0;
}

.col a:hover {
  color: var(--text-main);
  transform: translateX(2px);
}

.footer-bottom {
  text-align: center;
  padding: 24px 32px;
  background-color: var(--bg-primary);
  color: var(--text-muted);
  font-size: 12.5px;
  font-weight: 400;
  border-radius: 0 0 24px 24px;
}

/* ============================================================
   16. Back to Top 返回顶部按钮
   ============================================================ */
#backToTop {
  position: fixed;
  bottom: 32px;
  right: 32px;
  z-index: 999;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background-color: var(--bg-card);
  color: var(--text-secondary);
  border: none;
  font-size: 16px;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}

#backToTop.visible {
  opacity: 1;
  visibility: visible;
}

#backToTop:hover {
  background-color: var(--bg-surface);
  color: var(--text-main);
  transform: translateY(-2px);
}

/* ============================================================
   17. 响应式
   ============================================================ */
@media (max-width: 768px) {
  .container {
    padding: 20px 20px 32px;
  }

  .hero-title {
    font-size: 36px;
  }

  .section-title-large {
    font-size: 24px;
  }

  .grid-3col {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 32px;
  }

  .brand-col {
    grid-column: 1 / -1;
  }

  .stats-row {
    gap: 32px;
    flex-wrap: wrap;
    padding: 32px 24px;
  }

  .metrics-grid {
    gap: 32px;
  }

  .navbar {
    width: calc(100% - 24px);
    border-radius: 16px;
    flex-wrap: wrap;
    justify-content: space-between;
    gap: 16px;
    padding: 12px 18px;
  }

  .nav-links {
    gap: 18px;
    flex-wrap: wrap;
    justify-content: center;
  }

  .product-grid {
    grid-template-columns: 1fr;
  }

  .newsletter-form input {
    width: 100%;
  }

  .newsletter-box {
    padding: 40px 24px;
  }

  .blog-item {
    flex-direction: column;
    align-items: flex-start;
    gap: 6px;
  }

  .blog-item .date {
    min-width: auto;
  }
}