/* 双端适配最佳实践 */

/* 1. CSS Reset - 基础重置 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: 'PingFang SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  line-height: 1.6;
  color: #333;
  background-color: #fff;
}

/* 2. 响应式断点定义 - 使用 CSS Variables */
:root {
  --breakpoint-sm: 576px;
  --breakpoint-md: 768px;
  --breakpoint-lg: 992px;
  --breakpoint-xl: 1200px;
  
  --primary-color: #1E40AF;
  --primary-light: #3B82F6;
  --primary-dark: #1E3A8A;
  --accent-color: #06B6D4;
  --bg-dark: #0F172A;
  --bg-gradient: linear-gradient(135deg, #0F172A 0%, #1E3A8A 50%, #3B82F6 100%);
}

/* 3. Container - 响应式容器 */
.container {
  width: 100%;
  padding-right: 15px;
  padding-left: 15px;
  margin-right: auto;
  margin-left: auto;
}

@media (min-width: 576px) {
  .container {
    max-width: 540px;
  }
}

@media (min-width: 768px) {
  .container {
    max-width: 720px;
  }
}

@media (min-width: 992px) {
  .container {
    max-width: 960px;
  }
}

@media (min-width: 1200px) {
  .container {
    max-width: 1140px;
  }
}

/* 4. 导航栏 - 移动端优先设计 */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: transparent;
  transition: background 0.3s ease;
}

.navbar.scrolled {
  background: rgba(20, 24, 58, 0.2);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(1px);
}

.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
}

.navbar-brand {
  display: flex;
  align-items: center;
  gap: 8px;
  color: #fff;
  font-weight: 400;
  font-size: 1rem;
}

.logo {
  height: 32px;
  width: auto;
}

.desktop-logo {
  display: none;
}

.mobile-logo {
  display: block;
}

.navbar-nav {
  display: none;
}

.navbar-actions {
  display: none;
}

.mobile-menu-btn {
  display: flex;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}

.mobile-menu-btn span {
  width: 24px;
  height: 2px;
  background: #fff;
  border-radius: 1px;
}

.mobile-menu {
  display: none;
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  background: rgba(15, 23, 42, 0.98);
  padding: 15px;
}

.mobile-menu.active {
  display: block;
}

.mobile-menu ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 15px;
}

.mobile-menu a {
  color: #fff;
  text-decoration: none;
  font-size: 1rem;
  position: relative;
  outline: none;
}

.mobile-menu a:hover,
.mobile-menu a:active,
.mobile-menu a:focus {
  color: #AEAAFF;
}

.mobile-menu a:hover::after,
.mobile-menu a:active::after,
.mobile-menu a:focus::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 50%;
  transform: translateX(-50%);
  width: 30px;
  height: 2px;
  background: #AEAAFF;
}

.mobile-menu button {
  color: #fff;
  text-decoration: none;
  font-size: 1rem;
}

.mobile-menu .btn {
  width: 100%;
  margin-top: 10px;
}

/* 750px以上显示桌面端logo */
@media (min-width: 750px) {
  .desktop-logo {
    display: block;
  }
  
  .mobile-logo {
    display: none;
  }
  
  .navbar-nav {
    display: flex;
    list-style: none;
    gap: 60px;
  }
  
  .navbar-nav a {
    color: #fff;
    text-decoration: none;
    font-size: 0.9375rem;
    transition: color 0.3s ease;
    position: relative;
    outline: none;
  }
  
  .navbar-nav a:hover,
  .navbar-nav a:active,
  .navbar-nav a:focus {
    color: #AEAAFF;
  }
  
  .navbar-nav a:hover::after,
  .navbar-nav a:active::after,
  .navbar-nav a:focus::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 50%;
    transform: translateX(-50%);
    width: 30px;
    height: 2px;
    background: #AEAAFF;
  }
  
  .mobile-menu-btn {
    display: none;
  }
  
  .mobile-menu {
    display: none;
  }
}

/* 桌面端导航 */
@media (min-width: 992px) {
  .navbar .container {
    height: 80px;
  }
  
  .navbar-brand {
    font-size: 1.25rem;
    gap: 12px;
  }
  
  .logo {
    height: 40px;
  }
  
  .navbar-actions {
    display: flex;
    gap: 15px;
  }
}

/* 5. 按钮样式 - 统一设计 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 20px;
  font-size: 0.875rem;
  font-weight: 500;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.3s ease;
  text-decoration: none;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary-light) 0%, var(--primary-color) 100%);
  color: #fff;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 25px rgba(59, 130, 246, 0.3);
}

.btn-outline {
  background: transparent;
  color: #fff;
  border: 1px solid rgba(255, 255, 255, 0.3);
}

.btn-outline:hover {
  background: rgba(255, 255, 255, 0.1);
}

@media (min-width: 992px) {
  .btn {
    padding: 12px 28px;
    font-size: 0.9375rem;
    border-radius: 12px;
  }
}

/* 6. Hero区域 - 响应式布局 */
.hero {
  position: relative;
  overflow: hidden;
  background-image: url('https://engma-ai.oss-cn-beijing.aliyuncs.com/750/banner.png');
  background-size: 100% auto;
  background-position: center top;
  background-repeat: no-repeat;
  padding-top: 90px;
  padding-bottom: 16px;
  display: flex;
  align-items: flex-end;
  justify-content: flex-start;
  min-height: 0;
  aspect-ratio: 750 / 420;
  background-color: #070b3d;
}

.hero-content {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  justify-content: flex-end;
  gap: 20px;
  position: relative;
  z-index: 1;
  width: 100%;
  padding-left: 20px;
}

.hero-text {
  text-align: center;
  padding: 0 20px;
}

.hero-cta-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  background: linear-gradient(90deg, #53AEFF 0%, #565BFC 100%);
  border: none;
  border-radius: 45px;
  cursor: pointer;
  padding: 12px 24px;
  margin-top: 30px;
  margin-left: auto;
  margin-right: auto;
  font-family: AlibabaPuHuiTi_2_55_Regular, 'PingFang SC', sans-serif;
  font-size: 18px;
  color: #FFFFFF;
  line-height: 1.4;
  outline: none;
  transition: all 0.3s ease;
  width: 100%;
  max-width: 240px;
  box-shadow: 0 8px 20px rgba(86, 91, 252, 0.3);
}

.hero-cta-btn:hover {
  transform: translateY(-3px);
  filter: brightness(1.1);
  box-shadow: 0 8px 25px rgba(83, 174, 255, 0.5);
}

.hero-cta-btn img {
  width: auto;
  height: 16px;
  display: block;
}

@media (max-width: 999px) {
  .hero-content {
    position: static;
  }

  .hero-cta-btn {
    position: absolute;
    left: 20px;
    bottom: 12px;
    margin: 0;
  }
}


/* ==========================================================================
   媒体查询：当中大屏幕（PC端 / iPad横屏）时，恢复你原本的设计稿尺寸
   ========================================================================== */
@media (min-width: 750px) {
  .hero {
    padding-top: 60px;
    padding-bottom: 40px;
    aspect-ratio: 1920 / 900;
    min-height: 520px;
    background-size: cover;
    position: relative;
  }

  .hero-content {
    align-items: flex-start;
    gap: 30px;
  }

  .hero-text {
    text-align: left;
    padding: 0;
  }

  .hero-cta-btn {
    padding: 15px 30px;
    margin-top: 20px;
    margin-left: 0;
    font-size: 24px;
    line-height: 38px;
    max-width: 280px;
  }
  
  .hero-cta-btn img {
    height: 20px;
  }
}

/* 7. 通用区块样式 */
section {
  padding: 40px 0;
}

.section-title {
  text-align: left;
  font-size: 1.5rem;
  font-weight: 600;
  color: #14183A;
  margin-bottom: 20px;
}

.section-subtitle {
  font-size: 0.9375rem;
  color: rgba(20, 24, 58, 0.6);
  line-height: 1.8;
  margin-bottom: 30px;
}

@media (min-width: 768px) {
  section {
    padding: 60px 0;
  }
  
  .section-title {
    font-size: 2rem;
    margin-bottom: 40px;
  }
}

/* 8. 关于我们 - 响应式布局 */
.about-content {
  display: flex;
  flex-direction: column;
  gap: 30px;
}

.about-text p {
  font-size: 0.9375rem;
  line-height: 1.8;
  color: rgba(20, 24, 58, 0.6);
  text-align: justify;
}

.about-image img {
  width: 100%;
  border-radius: 12px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

/* 轮播图样式 */
.carousel {
  position: relative;
  width: min(100%, calc(100vw - 30px), 493px);
  max-width: 493px;
  overflow: hidden;
  border-radius: 12px;
  margin: 0 auto;
}

.carousel-track {
  display: flex;
  transition: transform 0.5s ease;
}

.carousel-slide {
  min-width: 100%;
  display: none;
}

.carousel-slide.active {
  display: block;
}

.carousel-slide img {
  width: 100%;
  height: auto;
  aspect-ratio: 493 / 275;
  object-fit: cover;
  border-radius: 12px;
  display: block;
  margin: 0 auto;
}

.carousel-progress {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  margin-top: 15px;
}

.progress-dots {
  display: flex;
  justify-content: center;
  gap: 8px;
}

.progress-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: rgba(86, 91, 252, 0.3);
  cursor: pointer;
  transition: all 0.3s ease;
}

.progress-dot.active {
  background: #565BFC;
  width: 20px;
  border-radius: 4px;
}

/* 大于440px时的轮播图样式 */
@media (min-width: 440px) {
  .carousel {
    width: min(100%, calc(100vw - 30px), 493px);
    height: 275px;
    border-radius: 18px;
    margin: 0 auto;
  }
  
  .carousel-slide img {
    width: 100%;
    height: 275px;
    aspect-ratio: auto;
    border-radius: 18px;
  }
}

/* 大于750px时的轮播图样式 */
@media (min-width: 750px) {
  .carousel {
    width: min(100%, 493px);
    height: 275px;
    border-radius: 18px;
    margin: 0;
  }

  .carousel-slide img {
    width: 100%;
    height: 275px;
    aspect-ratio: auto;
    border-radius: 18px;
  }

  .carousel-progress {
    margin-top: 15px;
    text-align: center;
  }
}

@media (min-width: 992px) {
  .about-content {
    flex-direction: row;
    align-items: center;
    gap: 40px;
  }
  
  .about-text {
    flex: 1;
  }
  
  .about-image {
    flex: 1;
  }
  
  .about-text p {
    font-size: 1rem;
  }
}

/* 9. AI优势 - 响应式网格 */
.advantages-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 30px;
}

.advantage-card {
  background: #fff;
  padding: 30px;
  border-radius: 16px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
  text-align: center;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.advantage-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 30px rgba(59, 130, 246, 0.15);
}

.advantage-card .icon {
  width: 80px;
  height: 80px;
  margin: 0 auto 20px;
  border-radius: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.advantage-card .icon img {
  max-width: 100%;
  max-height: 100%;
  width: auto;
  height: auto;
  object-fit: contain;
}

.advantage-card h3 {
  font-size: 1.125rem;
  font-weight: 600;
  color: #14183A;
  margin-bottom: 10px;
}

.advantage-card p {
  font-size: 0.875rem;
  color: rgba(20, 24, 58, 0.6);
  line-height: 1.6;
}

@media (min-width: 768px) {
  .advantages-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
  }
}

@media (min-width: 992px) {
  .advantages-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
  }
}

/* 10. 公司实力 - 深色背景 */
.strength {
  background: var(--bg-dark);
  color: #fff;
  background-image: url('https://engma-ai.oss-cn-beijing.aliyuncs.com/750/公司实力.png');
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
}

.strength .section-title {
  color: #fff;
}

.strength .section-subtitle {
  color: #fff;
  margin-bottom: 40px;
}

.strength-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 30px;
  margin-bottom: 30px;
}

.strength-item {
  display: flex;
  align-items: center;
  gap: 15px;
  padding: 0;
  background: transparent;
  border-radius: 0;
}

.strength-icon {
  width: 63px;
  height: 64px;
  flex-shrink: 0;
  object-fit: contain;
}

.strength-item-content {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.strength-item .number {
  display: block;
  font-size: 1.75rem;
  font-weight: 700;
  color: #fff;
  line-height: 1.2;
}

.strength-item .label {
  display: block;
  font-size: 0.875rem;
  color: rgba(255, 255, 255, 0.8);
  margin-top: 4px;
}

@media (min-width: 750px) {
  .strength {
    background-image: url('https://engma-ai.oss-cn-beijing.aliyuncs.com/1920/公司实力.png');
  }
}

@media (min-width: 768px) {
  .strength-grid {
    grid-template-columns: repeat(4, 1fr);
    gap: 40px;
  }
  
  .strength-item .number {
    font-size: 2rem;
  }
}

/* 11. 企业文化 - 复杂布局适配 */
.culture {
  background-image: url('https://engma-ai.oss-cn-beijing.aliyuncs.com/750/企业文化.png');
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
  padding: 60px 20px;
  min-height: 0;
}

@media (min-width: 750px) {
  .culture {
    background-image: url('https://engma-ai.oss-cn-beijing.aliyuncs.com/1920/-10.png');
    padding: 80px 20px;
    min-height: 600px;
  }
}

.culture .container {
  position: relative;
  min-height: clamp(780px, 92vw, 980px);
}

.culture .section-title {
  position: relative;
  z-index: 2;
  margin-bottom: 0;
  max-width: 220px;
}

.culture-item {
  position: absolute;
  display: flex;
  align-items: flex-start;
  gap: 14px;
  width: clamp(220px, 24vw, 340px);
  min-height: clamp(280px, 32vw, 380px);
  padding: clamp(22px, 2.2vw, 28px) clamp(18px, 2vw, 24px);
  border-radius: 28px;
}

.culture-item.mission {
  top: clamp(40px, 6vw, 80px);
  left: clamp(240px, 33vw, 420px);
}

.culture-item.vision {
  top: clamp(320px, 37vw, 420px);
  right: clamp(20px, 11vw, 150px);
}

.culture-item.values {
  top: clamp(360px, 43vw, 500px);
  left: clamp(0px, 2vw, 40px);
}

.culture-icon {
  width: 30px;
  height: auto;
  flex-shrink: 0;
  object-fit: contain;
}

.culture-text {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.culture-item .label {
  font-size: 1.125rem;
  font-weight: 600;
  color: #0214F5;
  margin-bottom: 8px;
}

.culture-item p {
  font-size: 0.875rem;
  color: #14183A;
  line-height: 1.6;
  margin: 0;
  display: inline-block;
  padding: 6px 10px;
  border: 1px solid rgba(255, 255, 255, 0.55);
  border-radius: 14px;
  background: rgba(255, 255, 255, 0.28);
  box-shadow: 0 10px 24px rgba(47, 75, 170, 0.10);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
}

@media (max-width: 750px) {
  .culture {
    padding: 48px 16px;
  }

  .culture .container {
    min-height: clamp(700px, 118vw, 900px);
  }

  .culture .section-title {
    max-width: none;
  }

  .culture-item {
    width: clamp(180px, 26vw, 260px);
    min-height: clamp(240px, 38vw, 340px);
    border-radius: 24px;
  }

  .culture-item.mission {
    top: clamp(70px, 10vw, 110px);
    left: 50%;
    transform: translateX(-50%);
  }

  .culture-item.values {
    top: clamp(360px, 48vw, 500px);
    left: clamp(0px, 2vw, 20px);
  }

  .culture-item.vision {
    top: clamp(350px, 47vw, 490px);
    right: clamp(0px, 2vw, 20px);
  }
}

/* 12. 产品视频 - 响应式视频容器 */
.video-container {
  position: relative;
  border-radius: 16px;
  overflow: hidden;
  width: 100%;
  aspect-ratio: 16 / 9;
  max-width: 100%;
  margin: 0 auto;
  background: #000;
}

.video-container video {
  width: 100%;
  height: 100%;
  display: block;
  object-fit: contain;
}

@media (max-width: 750px) {
  .video-container {
    width: 100%;
    aspect-ratio: 16 / 9;
    border-radius: 24px;
  }
  
  .video-container video {
    object-fit: contain;
  }
}

.video-cover {
  width: 100%;
  height: 100%;
  display: block;
  object-fit: contain;
  background: #000;
  position: absolute;
  inset: 0;
}

.play-btn {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  background: transparent;
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
}

.video-container:hover .play-btn,
.video-container:focus-within .play-btn {
  opacity: 1;
  visibility: visible;
}

.play-btn img {
  width: auto;
  height: auto;
  max-width: 60px;
  max-height: 60px;
}

.play-btn:hover img {
  transform: scale(1.1);
}

.play-btn.always-visible {
  opacity: 1 !important;
  visibility: visible !important;
}

.video-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(34, 34, 34, 0.6);
  display: none;
  pointer-events: none;
}

/* 13. CTA区域 */
.cta {
  background-image: url('https://engma-ai.oss-cn-beijing.aliyuncs.com/1920/小程序二维码.png');
  background-size: 1100px auto;
  background-position: center;
  background-repeat: no-repeat;
  padding: 40px 20px;
  min-height: 400px;
}

.qrcode-img {
  display: none;
}

.cta-content {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  justify-content: center;
  gap: 5px;
  text-align: left;
  padding: 30px 0 30px 80px;
  min-height: 300px;
}

@media (max-width: 750px) {
  .cta {
    background-image: url('https://engma-ai.oss-cn-beijing.aliyuncs.com/750/小程序二维码.png');
    background-size: cover;
    min-height: 350px;
  }
  
  .cta-content {
    padding: 15px 25px;
    align-items: flex-start;
    text-align: left;
    margin-top: -100px;
  }
  
  .cta-text h3 {
    font-size: 1.25rem;
    margin-bottom: 5px;
  }
  
  .cta-text p {
    font-size: 0.875rem;
    margin-bottom: 15px;
  }
}

.cta-text h3 {
  font-size: 1.5rem;
  color: #fff;
  margin-bottom: 10px;
}

.cta-text p {
  font-size: 0.9375rem;
  color: rgba(255, 255, 255, 0.8);
  margin-bottom: 20px;
}

@media (max-width: 1023px) {
  .cta {
    background-image: url('https://engma-ai.oss-cn-beijing.aliyuncs.com/750/小程序二维码.png');
    background-size: min(100%, 620px) auto;
    background-position: center;
    padding: 32px 0;
    min-height: 360px;
  }

  .cta .container {
    max-width: 560px;
  }

  .cta-content {
    position: relative;
    min-height: 340px;
    padding: 26px 28px 0 0;
    align-items: stretch;
    justify-content: flex-start;
    gap: 0;
    margin-top: 0;
  }

  .cta-text {
    position: static;
    display: block;
    width: 100%;
    padding-top: 0;
  }

  .cta-text h3 {
    font-size: 2rem;
    line-height: 1.2;
    margin-bottom: 10px;
    max-width: 340px;
  }

  .cta-text p {
    font-size: 0.9375rem;
    line-height: 1.7;
    margin-bottom: 0;
    max-width: 340px;
  }

  .cta-text .btn {
    position: absolute;
    top: 20px;
    right: 0;
    padding: 12px 22px;
    min-height: auto;
    margin: 0;
    white-space: nowrap;
    border-radius: 999px;
  }
}

@media (max-width: 640px) {
  .cta-content {
    /* min-height: 400px; */
    padding: 20px 20px 0;
  }

  .cta-text {
    padding-top: 0;
  }

  .cta-text h3 {
    font-size: 1.5rem;
    max-width: none;
  }

  .cta-text p {
    max-width: none;
  }

  .cta-text .btn {
    top: 16px;
    right: 0;
    left: auto;
  }
}

/* 14. 联系我们 */
@media (max-width: 600px) {
  .cta-text {
    position: relative;
    top: 30px;
  }
}

.contact {
  padding: 60px 20px;
  background: #f8f9fa;
}

.contact-content {
  text-align: center;
}

.contact-text h3 {
  font-size: 1.5rem;
  color: var(--text-dark);
  margin-bottom: 30px;
}

.contact-qrcodes {
  display: flex;
  justify-content: center;
  gap: 40px;
  flex-wrap: wrap;
}

.qrcode-item {
  width: 120px;
  text-align: center;
}

.qrcode-item img {
  width: 100%;
  height: 120px;
  object-fit: contain;
  display: block;
  margin-bottom: 8px;
}

@media (max-width: 750px) {
  .contact-qrcodes {
    gap: 15px;
    max-width: 300px;
    margin: 0 auto;
  }
  
  .qrcode-item {
    width: calc(33.33% - 10px);
    height: auto;
  }
  
  .qrcode-item img {
    height: 80px;
  }
}

/* 15. 页脚 - 响应式布局 */
.footer {
  background: var(--bg-dark);
  color: #fff;
  padding: 40px 20px;
}

.footer-content {
  display: flex;
  flex-direction: column;
  gap: 30px;
}

.footer-brand {
  text-align: center;
}

.footer-logo {
  height: 40px;
  margin-bottom: 10px;
}

.footer-brand span {
  display: block;
  font-weight: 600;
  margin-bottom: 10px;
}

.footer-brand p {
  font-size: 0.875rem;
  color: rgba(255, 255, 255, 0.6);
}

.footer-links ul {
  list-style: none;
  text-align: center;
}

.footer-links h4 {
  margin-bottom: 15px;
  text-align: center;
}

.footer-links li {
  margin-bottom: 10px;
  font-size: 0.875rem;
  color: rgba(255, 255, 255, 0.6);
}

.footer-qr {
  text-align: center;
}

.footer-qr h4 {
  margin-bottom: 15px;
}

.footer-qr img {
  width: 100px;
  height: 100px;
}

.footer-bottom {
  text-align: center;
  padding-top: 30px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  font-size: 0.75rem;
  color: rgba(255, 255, 255, 0.4);
}

@media (min-width: 768px) {
  .footer-content {
    flex-direction: row;
    justify-content: space-between;
  }
  
  .footer-brand,
  .footer-links,
  .footer-qr {
    text-align: left;
  }
  
  .footer-links ul {
    text-align: left;
  }
}

/* 15. 移动端优化 - 触控友好 */
@media (max-width: 768px) {
  .btn {
    min-height: 44px;
    font-size: 1rem;
  }
  
  .navbar-nav a,
  .mobile-menu a {
    padding: 10px 0;
  }
}

/* 16. 性能优化 - 图片懒加载 */
img {
  loading: lazy;
}

/* 17. 无障碍支持 */
/* 强行关闭全站所有元素的聚焦蓝色边框 */
a:focus,
button:focus,
input:focus,
textarea:focus {
  outline: none !important;
}

/* 18. 打印样式 */
@media print {
  .navbar,
  .mobile-menu,
  .btn,
  .cta,
  .footer {
    display: none;
  }
  
  .hero {
    background: #fff;
  }
  
  .hero-text h1 {
    color: #333;
  }
}

@media (max-width: 600px) {
  .cta-copy-line1,
  .cta-copy-line2 {
    display: block;
  }
}

.volunteer-preview-open {
  overflow: hidden;
}

.volunteer-preview-modal {
  position: fixed;
  inset: 0;
  display: none;
  align-items: center;
  justify-content: center;
  padding: 16px;
  background: rgba(0, 0, 0, 0.92);
  z-index: 9999;
}

.volunteer-preview-modal.is-visible {
  display: flex;
}

.volunteer-preview-dialog {
  position: relative;
  width: min(100vw, 420px);
  height: min(100vh, 820px);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  background: #000;
}

.volunteer-preview-close {
  position: absolute;
  top: 10px;
  right: 10px;
  width: 36px;
  height: 36px;
  border: none;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.16);
  color: #fff;
  font-size: 24px;
  line-height: 1;
  cursor: pointer;
  z-index: 2;
}

.volunteer-preview-image-wrap {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 56px 0 32px;
}

.volunteer-preview-image {
  max-width: 100%;
  max-height: 100%;
  display: block;
  object-fit: contain;
}

.volunteer-preview-tip {
  margin: 0;
  padding: 0 20px 16px;
  text-align: center;
  color: rgba(255, 255, 255, 0.82);
  font-size: 14px;
  line-height: 1.6;
}