/* 全局重置与基础配置 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Roboto', 'Helvetica Neue', 'Microsoft Yahei', sans-serif;
}

:root {
  /* 品牌主色调：科技蓝+活力金，适配体育用品行业高端定位 */
  --primary: #0F52BA;
  --primary-light: #2A70D9;
  --secondary: #FFC107;
  --secondary-light: #FFD54F;
  --dark: #121212;
  --gray: #6C757D;
  --light-gray: #F8F9FA;
  --white: #FFFFFF;
  --shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}

body {
  color: var(--dark);
  background-color: var(--light-gray);
  line-height: 1.7;
}

a {
  text-decoration: none;
  color: inherit;
  transition: all 0.3s ease;
}

ul {
  list-style: none;
}

.container {
  width: 90%;
  max-width: 1200px;
  margin: 0 auto;
}

/* 响应式断点 */
@media (max-width: 992px) {
  .container {
    width: 95%;
  }
}

@media (max-width: 768px) {
  :root {
    font-size: 14px;
  }
}

/* 头部样式 - 响应式导航 */
.header {
  background-color: var(--white);
  box-shadow: var(--shadow);
  position: sticky;
  top: 0;
  z-index: 999;
  padding: 1rem 0;
}

.header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--primary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

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

/* 桌面端导航 */
.nav-desktop ul {
  display: flex;
  gap: 2rem;
}

.nav-desktop a {
  font-weight: 500;
  color: var(--dark);
  position: relative;
}

.nav-desktop a::after {
  content: '';
  position: absolute;
  bottom: -0.3rem;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--primary);
  transition: width 0.3s ease;
}

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

/* 移动端导航 */
.nav-mobile {
  display: none;
}

.nav-toggle {
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--primary);
}

.nav-mobile-menu {
  position: fixed;
  top: 0;
  right: 0;
  width: 80%;
  height: 100vh;
  background-color: var(--white);
  box-shadow: -2px 0 10px rgba(0, 0, 0, 0.1);
  padding: 2rem;
  transform: translateX(100%);
  transition: transform 0.3s ease;
  z-index: 1000;
}

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

.nav-mobile-menu .close-btn {
  font-size: 1.5rem;
  cursor: pointer;
  margin-bottom: 2rem;
  color: var(--dark);
}

.nav-mobile-menu ul {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.nav-mobile-menu a {
  font-weight: 500;
  color: var(--dark);
  font-size: 1.2rem;
}

@media (max-width: 768px) {
  .nav-desktop {
    display: none;
  }
  .nav-mobile {
    display: block;
  }
}

/* 按钮通用样式 */
.btn {
  display: inline-block;
  padding: 0.8rem 1.8rem;
  border-radius: 4px;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: all 0.3s ease;
}

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

.btn-primary:hover {
  background-color: var(--primary-light);
  transform: translateY(-2px);
  box-shadow: 0 4px 8px rgba(15, 82, 186, 0.3);
}

.btn-secondary {
  background-color: var(--secondary);
  color: var(--dark);
}

.btn-secondary:hover {
  background-color: var(--secondary-light);
  transform: translateY(-2px);
  box-shadow: 0 4px 8px rgba(255, 193, 7, 0.3);
}

/* 页面标题通用样式 */
.page-title {
  text-align: center;
  margin: 3rem 0 2rem;
  position: relative;
}

.page-title h2 {
  font-size: 2.2rem;
  color: var(--primary);
  font-weight: 700;
}

.page-title::after {
  content: '';
  position: absolute;
  bottom: -1rem;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 3px;
  background-color: var(--secondary);
}

/* 底部样式 */
.footer {
  background-color: var(--dark);
  color: var(--white);
  padding: 4rem 0 2rem;
  margin-top: 4rem;
}

.footer-top {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 2rem;
  margin-bottom: 2rem;
}

.footer-col h3 {
  font-size: 1.2rem;
  margin-bottom: 1.5rem;
  color: var(--secondary);
  position: relative;
  padding-bottom: 0.5rem;
}

.footer-col h3::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 40px;
  height: 2px;
  background-color: var(--secondary);
}

.footer-col ul li {
  margin-bottom: 0.8rem;
  opacity: 0.8;
  transition: opacity 0.3s ease;
}

.footer-col ul li:hover {
  opacity: 1;
}

.footer-bottom {
  text-align: center;
  padding-top: 2rem;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  font-size: 0.9rem;
  opacity: 0.7;
}

/* 响应式底部 */
@media (max-width: 768px) {
  .footer-top {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 480px) {
  .footer-top {
    grid-template-columns: 1fr;
  }
}

/* 首页专属样式 */
.hero {
  background: linear-gradient(rgba(15, 82, 186, 0.85), rgba(15, 82, 186, 0.85)), 
              url('https://tse-mm.bing.com/th?q=bet体育平台 专业体育用品') center/cover no-repeat;
  color: var(--white);
  padding: 6rem 0;
  text-align: center;
}

.hero h1 {
  font-size: 3rem;
  margin-bottom: 1.5rem;
  line-height: 1.2;
}

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

.hero p {
  font-size: 1.2rem;
  max-width: 800px;
  margin: 0 auto 2rem;
  opacity: 0.9;
}

.hero-btns {
  display: flex;
  justify-content: center;
  gap: 1.5rem;
  flex-wrap: wrap;
}

/* 首页核心优势 */
.features {
  padding: 4rem 0;
  background-color: var(--white);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
  margin-top: 2rem;
}

.feature-card {
  background-color: var(--light-gray);
  padding: 2rem;
  border-radius: 8px;
  text-align: center;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

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

.feature-icon {
  font-size: 2.5rem;
  color: var(--primary);
  margin-bottom: 1rem;
}

.feature-card h3 {
  color: var(--primary);
  margin-bottom: 1rem;
  font-size: 1.3rem;
}

/* 首页产品预览 */
.product-preview {
  padding: 4rem 0;
}

.product-preview-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
  margin-top: 2rem;
}

.product-card {
  background-color: var(--white);
  border-radius: 8px;
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: transform 0.3s ease;
}

.product-card:hover {
  transform: translateY(-5px);
}

.product-img {
  width: 100%;
  height: 200px;
  object-fit: cover;
}

.product-content {
  padding: 1.5rem;
}

.product-content h3 {
  font-size: 1.1rem;
  margin-bottom: 0.5rem;
  color: var(--primary);
}

.product-content p {
  color: var(--gray);
  font-size: 0.9rem;
}

/* 响应式首页布局 */
@media (max-width: 992px) {
  .features-grid, .product-preview-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .hero h1 {
    font-size: 2.5rem;
  }
}

@media (max-width: 768px) {
  .hero {
    padding: 4rem 0;
  }
  .hero h1 {
    font-size: 2rem;
  }
}

@media (max-width: 480px) {
  .features-grid, .product-preview-grid {
    grid-template-columns: 1fr;
  }
  .hero h1 {
    font-size: 1.8rem;
  }
  .hero-btns {
    flex-direction: column;
    align-items: center;
  }
}

/* 关于我们页面样式 */
.about-hero {
  background: linear-gradient(rgba(0, 0, 0, 0.7), rgba(0, 0, 0, 0.7)), 
              url('https://tse-mm.bing.com/th?q=bet体育平台 企业介绍') center/cover no-repeat;
  color: var(--white);
  padding: 4rem 0;
  text-align: center;
}

.about-hero h1 {
  font-size: 2.5rem;
  margin-bottom: 1rem;
}

.about-content {
  padding: 4rem 0;
  background-color: var(--white);
}

.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: center;
}

.about-img {
  width: 100%;
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.about-text h3 {
  font-size: 1.8rem;
  color: var(--primary);
  margin-bottom: 1.5rem;
}

.about-text p {
  margin-bottom: 1rem;
  color: var(--gray);
  line-height: 1.8;
}

/* 企业历程 */
.timeline {
  padding: 4rem 0;
  background-color: var(--light-gray);
}

.timeline-items {
  position: relative;
  max-width: 800px;
  margin: 0 auto;
}

.timeline-items::before {
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 2px;
  height: 100%;
  background-color: var(--primary);
}

.timeline-item {
  display: flex;
  justify-content: flex-end;
  padding-right: 50%;
  position: relative;
  margin-bottom: 2rem;
}

.timeline-item:nth-child(even) {
  justify-content: flex-start;
  padding-right: 0;
  padding-left: 50%;
}

.timeline-content {
  width: 90%;
  background-color: var(--white);
  padding: 1.5rem;
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.timeline-dot {
  position: absolute;
  top: 1.5rem;
  right: -9px;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background-color: var(--secondary);
  border: 3px solid var(--primary);
}

.timeline-item:nth-child(even) .timeline-dot {
  right: auto;
  left: -9px;
}

.timeline-content h4 {
  color: var(--primary);
  margin-bottom: 0.5rem;
}

/* 响应式关于我们 */
@media (max-width: 768px) {
  .about-grid {
    grid-template-columns: 1fr;
  }
  .timeline-items::before {
    left: 20px;
  }
  .timeline-item {
    padding-right: 0;
    padding-left: 50px;
    justify-content: flex-start;
  }
  .timeline-item:nth-child(even) {
    padding-left: 50px;
  }
  .timeline-dot {
    right: auto;
    left: 11px;
  }
  .timeline-item:nth-child(even) .timeline-dot {
    left: 11px;
  }
}

/* 产品中心页面样式 */
.product-categories {
  display: flex;
  justify-content: center;
  gap: 1rem;
  flex-wrap: wrap;
  margin: 2rem 0;
}

.category-btn {
  padding: 0.6rem 1.5rem;
  background-color: var(--white);
  border: 1px solid var(--primary);
  border-radius: 30px;
  color: var(--primary);
  font-weight: 500;
  cursor: pointer;
  transition: all 0.3s ease;
}

.category-btn.active, .category-btn:hover {
  background-color: var(--primary);
  color: var(--white);
}

.products-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
  margin-top: 2rem;
}

/* 响应式产品中心 */
@media (max-width: 992px) {
  .products-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 480px) {
  .products-grid {
    grid-template-columns: 1fr;
  }
}

/* 新闻资讯页面样式 */
.news-filter {
  display: flex;
  justify-content: center;
  gap: 1rem;
  margin: 2rem 0;
  flex-wrap: wrap;
}

.news-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.news-card {
  background-color: var(--white);
  border-radius: 8px;
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: transform 0.3s ease;
}

.news-card:hover {
  transform: translateY(-5px);
}

.news-img {
  width: 100%;
  height: 200px;
  object-fit: cover;
}

.news-content {
  padding: 1.5rem;
}

.news-meta {
  display: flex;
  gap: 1rem;
  font-size: 0.8rem;
  color: var(--gray);
  margin-bottom: 0.8rem;
}

.news-content h3 {
  font-size: 1.2rem;
  color: var(--primary);
  margin-bottom: 0.8rem;
}

.news-excerpt {
  color: var(--gray);
  font-size: 0.9rem;
  margin-bottom: 1rem;
}

.news-read {
  color: var(--primary);
  font-weight: 500;
  font-size: 0.9rem;
  display: inline-block;
}

/* 响应式新闻资讯 */
@media (max-width: 992px) {
  .news-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 480px) {
  .news-grid {
    grid-template-columns: 1fr;
  }
}

/* 案例展示页面样式 */
.case-filter {
  display: flex;
  justify-content: center;
  gap: 1rem;
  margin: 2rem 0;
  flex-wrap: wrap;
}

.cases-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2rem;
}

.case-card {
  background-color: var(--white);
  border-radius: 8px;
  overflow: hidden;
  box-shadow: var(--shadow);
}

.case-img {
  width: 100%;
  height: 250px;
  object-fit: cover;
}

.case-content {
  padding: 2rem;
}

.case-content h3 {
  color: var(--primary);
  margin-bottom: 1rem;
  font-size: 1.4rem;
}

.case-tag {
  display: inline-block;
  padding: 0.3rem 0.8rem;
  background-color: var(--light-gray);
  color: var(--primary);
  border-radius: 30px;
  font-size: 0.8rem;
  margin-bottom: 1rem;
}

.case-desc {
  color: var(--gray);
  line-height: 1.8;
}

/* 响应式案例展示 */
@media (max-width: 768px) {
  .cases-grid {
    grid-template-columns: 1fr;
  }
}

/* 联系我们页面样式 */
.contact-wrapper {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  margin-top: 2rem;
}

.contact-info {
  background-color: var(--white);
  padding: 2rem;
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.contact-info-item {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  margin-bottom: 2rem;
}

.contact-icon {
  font-size: 1.5rem;
  color: var(--primary);
  background-color: var(--light-gray);
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.contact-text h4 {
  color: var(--primary);
  margin-bottom: 0.5rem;
}

.contact-text p {
  color: var(--gray);
}

.contact-form {
  background-color: var(--white);
  padding: 2rem;
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.form-group {
  margin-bottom: 1.5rem;
}

.form-group label {
  display: block;
  margin-bottom: 0.5rem;
  color: var(--dark);
  font-weight: 500;
}

.form-control {
  width: 100%;
  padding: 0.8rem 1rem;
  border: 1px solid var(--gray);
  border-radius: 4px;
  font-size: 1rem;
  transition: border-color 0.3s ease;
}

.form-control:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 2px rgba(15, 82, 186, 0.1);
}

textarea.form-control {
  resize: vertical;
  min-height: 150px;
}

/* 响应式联系我们 */
@media (max-width: 768px) {
  .contact-wrapper {
    grid-template-columns: 1fr;
  }
}