/* ============================================
   企业通用网站模板 — 主样式表
   版本: 1.1
   说明: 修改 :root 中的变量即可全局换肤
   ============================================ */

/* ---------- CSS 变量（一键换肤） ---------- */
:root {
  --color-primary: #2563eb;
  --color-primary-rgb: 37, 99, 235;
  --color-primary-dark: #1d4ed8;
  --color-primary-light: #3b82f6;
  --color-accent: #f59e0b;
  --color-accent-bg: #eff6ff;
  --color-bg: #ffffff;
  --color-bg-alt: #f8fafc;
  --color-bg-dark: #0f172a;
  --color-text: #1e293b;
  --color-text-light: #64748b;
  --color-text-white: #ffffff;
  --color-border: #e2e8f0;
  --color-success: #10b981;
  --color-error: #ef4444;
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Microsoft YaHei", "Helvetica Neue", sans-serif;
  --max-width: 1200px;
  --nav-height: 72px;
  --radius: 8px;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.08), 0 1px 2px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07), 0 2px 4px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.1), 0 4px 10px rgba(0, 0, 0, 0.06);
  --transition: 0.3s ease;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--nav-height);
}

body {
  font-family: var(--font-family);
  font-size: 16px;
  line-height: 1.7;
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
}

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

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

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

ul {
  list-style: none;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- 通用组件基类 ---------- */

/* 共用卡片样式 */
.card {
  background: #fff;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

/* 卡片悬浮上移 */
.card-lift {
  transition: transform var(--transition), box-shadow var(--transition);
}
.card-lift:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
}

/* 圆形图标容器 */
.circle-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
}

/* 三列网格（响应式覆写） */
.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
}

/* Hero 共用背景 */
.hero-bg {
  text-align: center;
  background: linear-gradient(135deg, var(--color-accent-bg) 0%, #dbeafe 100%);
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 32px;
  font-size: 16px;
  font-weight: 600;
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  transition: background-color var(--transition), color var(--transition),
    transform var(--transition), box-shadow var(--transition);
  text-align: center;
}

.btn-block {
  width: 100%;
}

.btn-primary {
  background: var(--color-primary);
  color: #fff;
}

.btn-primary:hover {
  background: var(--color-primary-dark);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  color: #fff;
}

.btn-outline {
  background: transparent;
  color: var(--color-primary);
  border: 2px solid var(--color-primary);
}

.btn-outline:hover {
  background: var(--color-primary);
  color: #fff;
}

.btn-white {
  background: #fff;
  color: var(--color-primary);
}

.btn-white:hover {
  background: var(--color-bg-alt);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

/* ---------- 导航栏 ---------- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: rgba(255, 255, 255, 0.95);
  z-index: 1000;
  transition: box-shadow var(--transition);
}

.navbar.scrolled {
  box-shadow: var(--shadow);
}

.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.nav-logo {
  font-size: 24px;
  font-weight: 800;
  color: var(--color-text);
  letter-spacing: -0.5px;
}

.nav-logo span {
  color: var(--color-primary);
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 36px;
}

.nav-menu a {
  color: var(--color-text);
  font-weight: 500;
  font-size: 15px;
  position: relative;
}

.nav-menu a::after {
  content: "";
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-primary);
  transition: width var(--transition);
}

.nav-menu a:hover::after,
.nav-menu a.active::after {
  width: 100%;
}

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

/* 汉堡菜单按钮 */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  transition: transform var(--transition), opacity var(--transition);
}

.nav-toggle.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.nav-toggle.active span:nth-child(2) {
  opacity: 0;
}

.nav-toggle.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* ---------- 区块通用 ---------- */
.section {
  padding: 100px 0;
}

.section-alt {
  background: var(--color-bg-alt);
}

.section-header {
  text-align: center;
  margin-bottom: 60px;
}

.section-header h2 {
  font-size: 36px;
  font-weight: 800;
  color: var(--color-text);
  margin-bottom: 12px;
}

.section-header p {
  font-size: 18px;
  color: var(--color-text-light);
}

/* ---------- Hero ---------- */
.hero {
  padding: 160px 0 100px;
  /* 继承 .hero-bg */
  text-align: center;
  background: linear-gradient(135deg, var(--color-accent-bg) 0%, #dbeafe 50%, #bfdbfe 100%);
}

.hero h1 {
  font-size: 48px;
  font-weight: 900;
  line-height: 1.2;
  margin-bottom: 20px;
  color: var(--color-text);
}

.hero h1 span {
  color: var(--color-primary);
}

.hero p {
  font-size: 20px;
  color: var(--color-text-light);
  max-width: 600px;
  margin: 0 auto 36px;
}

.hero-buttons {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

/* ---------- 服务卡片 ---------- */
.services-grid {
  gap: 32px;
}

.service-card {
  padding: 40px 32px;
  transition: transform var(--transition), box-shadow var(--transition);
  text-align: center;
}

.service-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-lg);
}

.service-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 72px;
  height: 72px;
  border-radius: 50%;
  background: var(--color-accent-bg);
  margin-bottom: 24px;
  font-size: 32px;
}

.service-card h3 {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 12px;
}

.service-card p {
  color: var(--color-text-light);
  font-size: 15px;
}

/* ---------- 案例展示 ---------- */
.cases-grid {
  gap: 24px;
}

.case-card {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  cursor: pointer;
}

.case-card img {
  width: 100%;
  height: 260px;
  object-fit: cover;
  transition: transform 0.5s ease;
}

.case-card:hover img {
  transform: scale(1.08);
}

.case-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(to top, rgba(0, 0, 0, 0.75) 0%, rgba(0, 0, 0, 0.1) 60%);
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  padding: 24px;
  color: #fff;
  opacity: 0;
  transition: opacity var(--transition);
}

.case-card:hover .case-overlay {
  opacity: 1;
}

.case-overlay h4 {
  font-size: 18px;
  margin-bottom: 4px;
}

.case-overlay span {
  font-size: 13px;
  opacity: 0.85;
}

/* 图片加载失败回退 */
.img-fallback {
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 18px;
}

/* ---------- 评价 ---------- */
.testimonials {
  gap: 32px;
}

.testimonial-card {
  padding: 36px 28px;
}

.testimonial-card > p {
  font-size: 15px;
  color: var(--color-text);
  line-height: 1.8;
  margin-bottom: 20px;
  font-style: italic;
}

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

.testimonial-author .avatar {
  width: 44px;
  height: 44px;
  background: var(--color-primary-light);
  color: #fff;
  font-weight: 700;
  font-size: 18px;
}

.testimonial-author strong {
  display: block;
  font-size: 15px;
}

.testimonial-author span {
  font-size: 13px;
  color: var(--color-text-light);
}

/* ---------- CTA ---------- */
.cta {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
  color: #fff;
  text-align: center;
  padding: 80px 0;
}

.cta h2 {
  font-size: 36px;
  font-weight: 800;
  margin-bottom: 16px;
}

.cta p {
  font-size: 18px;
  opacity: 0.9;
  margin-bottom: 32px;
}

/* ---------- 页脚 ---------- */
.footer {
  background: var(--color-bg-dark);
  color: #94a3b8;
  padding: 60px 0 30px;
}

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

.footer h3 {
  color: #fff;
  font-size: 18px;
  margin-bottom: 16px;
}

.footer-brand h3 span {
  color: var(--color-primary);
}

.footer a {
  color: #94a3b8;
  font-size: 14px;
  display: block;
  margin-bottom: 8px;
}

.footer a:hover {
  color: #fff;
}

.footer-brand p {
  font-size: 14px;
  margin-top: 12px;
  max-width: 280px;
}

.footer-bottom {
  border-top: 1px solid #1e293b;
  padding-top: 24px;
  text-align: center;
  font-size: 14px;
}

/* ---------- 页面标题栏 ---------- */
.page-hero {
  padding: 160px 0 60px;
  /* 继承 .hero-bg */
  text-align: center;
  background: linear-gradient(135deg, var(--color-accent-bg) 0%, #dbeafe 100%);
}

.page-hero h1 {
  font-size: 40px;
  font-weight: 900;
}

.page-hero p {
  font-size: 18px;
  color: var(--color-text-light);
  margin-top: 8px;
}

/* ---------- 关于页 ---------- */
.about-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.about-text h2 {
  font-size: 32px;
  font-weight: 800;
  margin-bottom: 20px;
}

.about-text p {
  color: var(--color-text-light);
  margin-bottom: 16px;
  line-height: 1.9;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: 36px;
}

.stat-item {
  text-align: center;
  padding: 24px;
}

.stat-item strong {
  display: block;
  font-size: 36px;
  font-weight: 900;
  color: var(--color-primary);
}

.stat-item span {
  font-size: 14px;
  color: var(--color-text-light);
}

.about-image {
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
}

/* 团队 */
.team-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 28px;
}

.team-card {
  text-align: center;
  padding: 32px 20px;
  transition: transform var(--transition), box-shadow var(--transition);
}

.team-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
}

.team-avatar {
  width: 100px;
  height: 100px;
  margin: 0 auto 16px;
  background: #e2e8f0;
  font-size: 40px;
}

.team-card h4 {
  font-size: 17px;
  margin-bottom: 4px;
}

.team-card > span {
  font-size: 14px;
  color: var(--color-text-light);
}

.team-bio {
  font-size: 13px;
  color: var(--color-text-light);
  margin-top: 8px;
}

/* 时间线 */
.timeline {
  position: relative;
  max-width: 800px;
  margin: 0 auto;
  padding-left: 40px;
}

.timeline::before {
  content: "";
  position: absolute;
  left: 15px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--color-border);
}

.timeline-item {
  position: relative;
  padding-bottom: 36px;
}

.timeline-item::before {
  content: "";
  position: absolute;
  left: -33px;
  top: 4px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--color-primary);
  border: 3px solid #fff;
  box-shadow: 0 0 0 2px var(--color-primary);
}

.timeline-item h4 {
  font-size: 18px;
  margin-bottom: 4px;
}

.timeline-item .year {
  font-size: 14px;
  color: var(--color-primary);
  font-weight: 700;
}

.timeline-item p {
  font-size: 14px;
  color: var(--color-text-light);
  margin-top: 4px;
}

/* ---------- 产品页 ---------- */
.product-filters {
  display: flex;
  justify-content: center;
  gap: 12px;
  margin-bottom: 40px;
  flex-wrap: wrap;
}

.filter-btn {
  padding: 8px 24px;
  border: 1px solid var(--color-border);
  background: #fff;
  border-radius: 9999px;
  cursor: pointer;
  font-size: 14px;
  font-weight: 500;
  transition: background-color var(--transition), color var(--transition),
    border-color var(--transition);
}

.filter-btn:hover,
.filter-btn.active {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
}

.products-grid {
  gap: 28px;
}

.product-card {
  overflow: hidden;
  transition: transform var(--transition), box-shadow var(--transition),
    opacity 0.3s ease;
}

.product-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
}

/* 筛选隐藏状态（由 JS 切换） */
.product-card.filtered {
  opacity: 0;
  transform: translateY(10px);
  pointer-events: none;
}

.product-card .product-img {
  height: 220px;
  background: linear-gradient(135deg, var(--grad, var(--color-bg-alt), #dbeafe));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 48px;
}

.product-card .product-info {
  padding: 20px;
}

.product-card h3 {
  font-size: 18px;
  margin-bottom: 6px;
}

.product-card p {
  font-size: 14px;
  color: var(--color-text-light);
  margin-bottom: 12px;
}

.product-tag {
  display: inline-block;
  padding: 3px 12px;
  background: var(--color-accent-bg);
  color: var(--color-primary);
  border-radius: 9999px;
  font-size: 12px;
  font-weight: 600;
}

/* ---------- 联系页 ---------- */
.contact-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
}

.contact-info h2 {
  font-size: 32px;
  font-weight: 800;
  margin-bottom: 16px;
}

.contact-info > p {
  color: var(--color-text-light);
  margin-bottom: 32px;
}

.contact-detail {
  display: flex;
  align-items: flex-start;
  gap: 16px;
  margin-bottom: 24px;
}

.contact-detail .icon {
  flex-shrink: 0;
  width: 48px;
  height: 48px;
  background: var(--color-accent-bg);
  font-size: 20px;
}

.contact-detail h4 {
  font-size: 16px;
  margin-bottom: 2px;
}

.contact-detail p {
  font-size: 14px;
  color: var(--color-text-light);
}

/* 表单 */
.contact-form {
  padding: 36px;
  box-shadow: var(--shadow-lg);
}

.form-title {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 24px;
}

.form-group {
  margin-bottom: 20px;
}

.form-group label {
  display: block;
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 6px;
  color: var(--color-text);
}

.form-group input,
.form-group textarea,
.form-group select {
  width: 100%;
  padding: 12px 16px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  font-size: 15px;
  font-family: var(--font-family);
  transition: border-color var(--transition), box-shadow var(--transition);
  background: var(--color-bg-alt);
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(var(--color-primary-rgb), 0.1);
}

.form-group textarea {
  resize: vertical;
  min-height: 120px;
}

.form-group .error-msg {
  font-size: 13px;
  color: var(--color-error);
  margin-top: 4px;
  display: none;
}

.form-group.error input,
.form-group.error textarea {
  border-color: var(--color-error);
}

.form-group.error .error-msg {
  display: block;
}

.form-success {
  display: none;
  text-align: center;
  padding: 40px;
}

.form-success.show {
  display: block;
}

.form-success-icon {
  font-size: 56px;
  margin-bottom: 16px;
}

.form-success-title {
  margin-bottom: 8px;
}

.form-success-text {
  color: var(--color-text-light);
}

/* ---------- 返回顶部 ---------- */
.back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--color-primary);
  color: #fff;
  border: none;
  cursor: pointer;
  font-size: 20px;
  box-shadow: var(--shadow-md);
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: opacity var(--transition), visibility var(--transition),
    transform var(--transition), background-color var(--transition);
  z-index: 999;
}

.back-to-top.show {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  background: var(--color-primary-dark);
}

/* ---------- 滚动动画 ---------- */
.animate-on-scroll {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.animate-on-scroll.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ============================================
   响应式
   ============================================ */

/* 平板 (≤992px) */
@media (max-width: 992px) {
  .grid-3 {
    grid-template-columns: repeat(2, 1fr);
  }

  .team-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

  .about-content,
  .contact-layout {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .hero h1 {
    font-size: 36px;
  }

  .section-header h2 {
    font-size: 28px;
  }
}

/* 手机 (≤768px) */
@media (max-width: 768px) {
  .nav-toggle {
    display: flex;
  }

  .nav-menu {
    position: fixed;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: #fff;
    flex-direction: column;
    padding: 24px;
    gap: 20px;
    box-shadow: var(--shadow-lg);
    transform: translateY(-120%);
    transition: transform var(--transition);
  }

  .nav-menu.active {
    transform: translateY(0);
  }

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

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

  .stats-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
  }

  .stat-item {
    padding: 16px 8px;
  }

  .stat-item strong {
    font-size: 24px;
  }

  .hero {
    padding: 120px 0 60px;
  }

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

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

  .section {
    padding: 60px 0;
  }

  .section-header {
    margin-bottom: 36px;
  }

  .section-header h2 {
    font-size: 24px;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 28px;
  }

  .product-filters {
    gap: 8px;
  }

  .filter-btn {
    padding: 6px 16px;
    font-size: 13px;
  }
}

/* 小手机 (≤480px) */
@media (max-width: 480px) {
  .team-grid {
    grid-template-columns: 1fr;
  }

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

  .hero-buttons {
    flex-direction: column;
    align-items: center;
  }

  .contact-form {
    padding: 24px;
  }
}