/* ============================================
   穗莹科技 - 全局样式表
   设计系统：Stripe/Vercel 蓝白现代风
   ============================================ */

/* --- CSS 变量（设计令牌） --- */
:root {
  --color-primary: #2563EB;
  --color-primary-hover: #1D4ED8;
  --color-primary-light: #DBEAFE;
  --color-secondary: #7C3AED;
  --color-secondary-hover: #6D28D9;
  --color-secondary-light: #EDE9FE;
  --color-bg: #F8FAFC;
  --color-surface: #FFFFFF;
  --color-text: #1E293B;
  --color-text-secondary: #64748B;
  --color-text-muted: #94A3B8;
  --color-border: #E2E8F0;
  --color-border-light: #F1F5F9;
  --color-success: #10B981;
  --color-warning: #F59E0B;
  --color-error: #EF4444;

  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial,
    "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-mono: "SF Mono", "Fira Code", "Cascadia Code", Consolas, monospace;

  --nav-height: 72px;
  --max-width: 1200px;
}

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

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

body {
  font-family: var(--font-sans);
  color: var(--color-text);
  background-color: var(--color-bg);
  line-height: 1.6;
  font-size: 16px;
  padding-top: var(--nav-height);
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color 0.2s ease;
}
a:hover {
  color: var(--color-primary-hover);
}

img {
  max-width: 100%;
  height: auto;
}

ul, ol {
  list-style: none;
}

/* --- 容器 --- */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* --- 按钮 --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: var(--radius-md);
  font-size: 15px;
  font-weight: 500;
  line-height: 1;
  cursor: pointer;
  border: none;
  transition: all 0.2s ease;
  text-decoration: none;
  white-space: nowrap;
}
.btn-primary {
  background-color: var(--color-primary);
  color: #fff;
}
.btn-primary:hover {
  background-color: var(--color-primary-hover);
  color: #fff;
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}
.btn-secondary {
  background-color: var(--color-secondary);
  color: #fff;
}
.btn-secondary:hover {
  background-color: var(--color-secondary-hover);
  color: #fff;
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}
.btn-outline {
  background-color: transparent;
  color: var(--color-primary);
  border: 1.5px solid var(--color-border);
}
.btn-outline:hover {
  border-color: var(--color-primary);
  background-color: var(--color-primary-light);
  color: var(--color-primary-hover);
}
.btn-lg {
  padding: 16px 32px;
  font-size: 16px;
}

/* --- 导航栏 --- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background-color: rgba(255, 255, 255, 0.97);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--color-border);
  z-index: 1000;
  transition: box-shadow 0.3s ease;
}
.navbar.scrolled {
  box-shadow: var(--shadow-sm);
}
.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}
.navbar-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 20px;
  font-weight: 700;
  color: var(--color-text);
  text-decoration: none;
}
.navbar-brand:hover {
  color: var(--color-primary);
}
.navbar-brand .brand-icon {
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 18px;
  font-weight: 700;
}
.navbar-menu {
  display: flex;
  align-items: center;
  gap: 8px;
}
.navbar-menu a {
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  color: var(--color-text-secondary);
  font-size: 15px;
  font-weight: 500;
  text-decoration: none;
  transition: all 0.2s ease;
}
.navbar-menu a:hover,
.navbar-menu a.active {
  color: var(--color-primary);
  background-color: var(--color-primary-light);
}
.navbar-phone {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  margin-left: 12px;
  color: var(--color-primary);
  font-weight: 600;
  font-size: 14px;
  border-left: 1px solid var(--color-border);
}
.navbar-phone i {
  font-size: 14px;
}

/* 汉堡菜单按钮 */
.navbar-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 36px;
  height: 36px;
  padding: 6px;
  border: none;
  background: none;
  cursor: pointer;
  border-radius: var(--radius-sm);
  transition: background-color 0.2s ease;
}
.navbar-toggle:hover {
  background-color: var(--color-border-light);
}
.navbar-toggle span {
  display: block;
  width: 100%;
  height: 2px;
  background-color: var(--color-text);
  border-radius: 2px;
  transition: all 0.3s ease;
}
.navbar-toggle.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}
.navbar-toggle.active span:nth-child(2) {
  opacity: 0;
}
.navbar-toggle.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* --- 页面头部通用 --- */
.page-hero {
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  color: #fff;
  padding: 80px 0;
  text-align: center;
}
.page-hero h1 {
  font-size: 40px;
  font-weight: 700;
  margin-bottom: 16px;
}
.page-hero p {
  font-size: 18px;
  opacity: 0.9;
  max-width: 600px;
  margin: 0 auto;
}

/* --- 段落间距 --- */
.section {
  padding: 80px 0;
}
.section-title {
  font-size: 32px;
  font-weight: 700;
  margin-bottom: 12px;
  text-align: center;
}
.section-subtitle {
  font-size: 16px;
  color: var(--color-text-secondary);
  text-align: center;
  max-width: 600px;
  margin: 0 auto 48px;
}

/* --- 卡片 --- */
.card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 24px;
  transition: all 0.2s ease;
}
.card:hover {
  box-shadow: var(--shadow-md);
  border-color: transparent;
  transform: translateY(-2px);
}

/* --- 脚注 --- */
.footer {
  background-color: var(--color-text);
  color: var(--color-text-muted);
  padding: 48px 0 24px;
}
.footer-brand {
  font-size: 18px;
  font-weight: 700;
  color: #fff;
  margin-bottom: 12px;
}
.footer-links {
  display: flex;
  gap: 32px;
  flex-wrap: wrap;
  margin-bottom: 24px;
}
.footer-links a {
  color: var(--color-text-muted);
  font-size: 14px;
}
.footer-links a:hover {
  color: #fff;
}
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1);
  padding-top: 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  font-size: 13px;
}

/* --- 标签/徽章 --- */
.badge {
  display: inline-block;
  padding: 2px 10px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 500;
}
.badge-primary {
  background-color: var(--color-primary-light);
  color: var(--color-primary);
}
.badge-secondary {
  background-color: var(--color-secondary-light);
  color: var(--color-secondary);
}
.badge-success {
  background-color: #D1FAE5;
  color: var(--color-success);
}

/* --- 网格 --- */
.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}
.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

/* --- 响应式 --- */
@media (max-width: 1024px) {
  .grid-4 {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (max-width: 768px) {
  :root {
    --nav-height: 64px;
  }
  body {
    padding-top: var(--nav-height);
  }

  .navbar-toggle {
    display: flex;
  }
  .navbar-menu {
    display: none;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background-color: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    flex-direction: column;
    padding: 12px 24px;
    gap: 4px;
    box-shadow: var(--shadow-lg);
  }
  .navbar-menu.open {
    display: flex;
  }
  .navbar-menu a {
    width: 100%;
    padding: 12px 16px;
    font-size: 16px;
  }
  .navbar-phone {
    display: none;
  }
  .navbar-phone.mobile-visible {
    display: flex;
    margin-left: 0;
    border-left: none;
    padding: 12px 16px;
    width: 100%;
    justify-content: center;
  }

  .page-hero h1 {
    font-size: 28px;
  }
  .page-hero p {
    font-size: 16px;
  }

  .section {
    padding: 48px 0;
  }
  .section-title {
    font-size: 24px;
  }

  .grid-2, .grid-3, .grid-4 {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 16px;
  }
  .btn-lg {
    padding: 14px 24px;
  }
}

/* ============================================
   滚动渐入动画 + 卡片交互
   ============================================ */

/* 滚动渐入 */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.reveal.revealed {
  opacity: 1;
  transform: translateY(0);
}

/* 卡片 hover 上浮 */
.card-hover {
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}
.card-hover:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

/* 图片懒加载占位 */
img[loading="lazy"] {
  background: var(--color-border-light);
  min-height: 100px;
}