/* 主样式文件 - 现代科技风格 */
:root {
  --primary-color: #0066cc;
  --primary-rgb: 0, 102, 204;
  --secondary-color: #00aaff;
  --accent-color: #00ddff;
  --dark-color: #001a33;
  --light-color: #f0f8ff;
  --text-color: #333;
  --light-text: #fff;
  --border-radius: 8px;
  --box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
  --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
  --neon-glow: 0 0 10px rgba(0, 170, 255, 0.5), 0 0 20px rgba(0, 170, 255, 0.3),
    0 0 30px rgba(0, 170, 255, 0.1);
  --glass-bg: rgba(255, 255, 255, 0.1);
  --glass-border: 1px solid rgba(255, 255, 255, 0.2);
  --gradient-bg: linear-gradient(
    135deg,
    var(--primary-color),
    var(--secondary-color)
  );
}

/* 全局样式 */
body {
  background-color: #f9f9f9;
  overflow-x: hidden;
  font-family: "Segoe UI", "Microsoft YaHei", sans-serif;
  color: var(--text-color);
  line-height: 1.6;
}

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 15px;
}

.btn {
  display: inline-block;
  padding: 12px 30px;
  background: var(--gradient-bg);
  color: var(--light-text);
  border-radius: 30px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1px;
  box-shadow: 0 4px 15px rgba(0, 102, 204, 0.4);
  transition: var(--transition);
  position: relative;
  overflow: hidden;
  z-index: 1;
  border: none;
  cursor: pointer;
}

.btn:before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    135deg,
    var(--secondary-color),
    var(--primary-color)
  );
  z-index: -1;
  transition: var(--transition);
  opacity: 0;
}

.btn:hover:before {
  opacity: 1;
}

.btn:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 25px rgba(0, 102, 204, 0.5);
}

.btn:active {
  transform: translateY(1px);
}

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

.section-header h2 {
  font-size: 2.8rem;
  font-weight: 700;
  color: var(--dark-color);
  margin-bottom: 20px;
  position: relative;
  display: inline-block;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.section-header h2:after {
  content: "";
  position: absolute;
  bottom: -15px;
  left: 50%;
  transform: translateX(-50%);
  width: 100px;
  height: 4px;
  background: var(--gradient-bg);
  border-radius: 2px;
}

.section-header p {
  color: #666;
  font-size: 1.2rem;
  max-width: 700px;
  margin: 15px auto 0;
}

/* 头部样式 */
/* 头部导航优化样式 */
#header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: linear-gradient(135deg, rgba(255, 255, 255, 0.95), rgba(248, 250, 252, 0.95));
  backdrop-filter: blur(15px);
  -webkit-backdrop-filter: blur(15px);
  box-shadow: 0 4px 32px rgba(0, 0, 0, 0.08);
  border-bottom: 1px solid rgba(0, 102, 204, 0.1);
  transition: all 0.4s cubic-bezier(0.25, 0.8, 0.25, 1);
}

#header.scrolled {
  background: linear-gradient(135deg, rgba(255, 255, 255, 0.98), rgba(248, 250, 252, 0.98));
  box-shadow: 0 8px 40px rgba(0, 0, 0, 0.12);
  border-bottom: 1px solid rgba(0, 102, 204, 0.15);
}

#header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 18px 20px;
  max-width: 1200px;
  margin: 0 auto;
  position: relative;
}

/* Logo优化 */
.logo {
  flex: 0 0 auto;
  position: relative;
}

.logo h1 {
  font-size: 1.5rem;
  font-weight: 800;
  background: var(--gradient-bg);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: 0.5px;
  position: relative;
  white-space: nowrap;
  transition: var(--transition);
}

.logo h1:hover {
  transform: scale(1.02);
  filter: drop-shadow(0 2px 8px rgba(0, 102, 204, 0.3));
}

/* 导航菜单优化 */
nav {
  flex: 1 1 auto;
  display: flex;
  justify-content: center;
  margin: 0 40px;
}
.navbar {
  align-items: center;
  justify-content: space-between;
}
nav ul {
  display: flex;
  gap: 8px;
  align-items: center;
  padding: 8px 16px;
  background: rgba(255, 255, 255, 0.6);
  border-radius: 50px;
  backdrop-filter: blur(10px);
  border: 1px solid rgba(0, 102, 204, 0.1);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.05);
  transition: var(--transition);
}

nav ul:hover {
  background: rgba(255, 255, 255, 0.8);
  box-shadow: 0 6px 25px rgba(0, 0, 0, 0.08);
  border-color: rgba(0, 102, 204, 0.2);
}

nav ul li {
  position: relative;
}

nav ul li a {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-color);
  padding: 12px 20px;
  position: relative;
  transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
  white-space: nowrap;
  display: block;
  border-radius: 25px;
  overflow: hidden;
}

nav ul li a:before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: var(--gradient-bg);
  opacity: 0;
  transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
  border-radius: 25px;
  z-index: -1;
}

nav ul li a:hover:before {
  opacity: 0.1;
}

nav ul li a:hover {
  color: var(--primary-color);
  transform: translateY(-2px);
  box-shadow: 0 4px 15px rgba(0, 102, 204, 0.2);
}

nav ul li a.active {
  background: var(--gradient-bg);
  color: white;
  box-shadow: 0 4px 15px rgba(0, 102, 204, 0.3);
}

nav ul li a.active:before {
  opacity: 0;
}

/* 移动端菜单按钮优化 */
.menu-toggle {
  display: none;
  flex-direction: column;
  justify-content: space-around;
  width: 30px;
  height: 30px;
  background: transparent;
  border: none;
  cursor: pointer;
  padding: 0;
  z-index: 10;
  position: relative;
}

.menu-toggle span {
  width: 100%;
  height: 3px;
  background: var(--primary-color);
  border-radius: 2px;
  transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
  transform-origin: center;
}

.menu-toggle:hover span {
  background: var(--secondary-color);
}

.menu-toggle.active span:nth-child(1) {
  transform: rotate(45deg) translate(7px, 7px);
}

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

.menu-toggle.active span:nth-child(3) {
  transform: rotate(-45deg) translate(7px, -7px);
}

/* 导航额外优化样式 */
@media (min-width: 769px) {
  nav ul li a {
    position: relative;
    overflow: hidden;
  }

  nav ul li a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 2px;
    background: var(--gradient-bg);
    transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
    transform: translateX(-50%);
  }

  nav ul li a:hover::after,
  nav ul li a.active::after {
    width: 80%;
  }

  nav ul li a.active::after {
    background: rgba(255, 255, 255, 0.8);
  }
}

/* 头部滚动时的额外效果 */
#header.scrolled .logo h1 {
  font-size: 1.4rem;
}

#header.scrolled nav ul {
  background: rgba(255, 255, 255, 0.7);
}

/* 导航链接激活状态优化 */
nav ul li a.active {
  position: relative;
}

nav ul li a.active::before {
  opacity: 1 !important;
}

/* 横幅样式 */
#banner {
  height: 100vh;
  background: linear-gradient(
      135deg,
      rgba(0, 26, 51, 0.9),
      rgba(0, 102, 204, 0.8)
    ),
    url("../images/banner-bg.svg") no-repeat center center/cover;
  display: flex;
  align-items: center;
  text-align: center;
  position: relative;
  overflow: hidden;
}

#banner:before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: url("../images/tech-pattern.svg");
  opacity: 0.15;
  animation: moveBackground 30s linear infinite;
}

@keyframes moveBackground {
  0% {
    background-position: 0 0;
  }
  100% {
    background-position: 100% 100%;
  }
}

.banner-content {
  max-width: 800px;
  margin: 0 auto;
  padding: 0 15px;
  position: relative;
  z-index: 1;
  animation: fadeInUp 1s ease-out;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.banner-content h2 {
  font-size: 4rem;
  font-weight: 700;
  color: var(--light-text);
  margin-bottom: 25px;
  text-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
  letter-spacing: 1px;
}

.banner-content p {
  font-size: 1.4rem;
  color: var(--light-text);
  margin-bottom: 40px;
  text-shadow: 0 1px 5px rgba(0, 0, 0, 0.3);
  max-width: 700px;
  margin-left: auto;
  margin-right: auto;
}

/* 案例展示区域样式 */
#cases {
  padding: 120px 0;
  background-color: var(--light-color);
  position: relative;
  overflow: hidden;
}

#cases:before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: url("../images/tech-pattern.svg");
  opacity: 0.05;
  pointer-events: none;
}

.case-category {
  margin-bottom: 100px;
  position: relative;
}

.case-category:last-child {
  margin-bottom: 0;
}

.case-category h3 {
  font-size: 2.2rem;
  font-weight: 600;
  color: var(--dark-color);
  margin-bottom: 0;
  padding-bottom: 15px;
  display: inline-block;
  position: relative;
}

.case-category h3:after {
  content: none;
}

.case-items {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 30px;
}

@media (min-width: 1200px) {
  .case-items {
    grid-template-columns: repeat(4, 1fr);
    gap: 25px;
  }
}

/* 移除移动端适配 - 保持PC端样式 */

.case-item {
  background-color: #fff;
  border-radius: var(--border-radius);
  overflow: hidden;
  box-shadow: var(--box-shadow);
  transition: var(--transition);
  position: relative;
  top: 0;
}

.case-item:hover {
  transform: translateY(-15px);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
}

.case-image {
  height: 220px;
  overflow: hidden;
  position: relative;
}

.case-image:before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    to bottom,
    rgba(0, 102, 204, 0.1),
    rgba(0, 170, 255, 0.3)
  );
  opacity: 0;
  transition: var(--transition);
  z-index: 1;
}

.case-item:hover .case-image:before {
  opacity: 1;
}

.case-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.8s ease;
}

.case-item:hover .case-image img {
  transform: scale(1.1);
}

.product-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  height: 100%;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  position: relative;
  overflow: hidden;
}

.product-icon::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(45deg, rgba(255,255,255,0.1) 0%, rgba(255,255,255,0.05) 100%);
  z-index: 1;
}

.product-icon i {
  font-size: 4rem;
  color: #ffffff;
  z-index: 2;
  position: relative;
  text-shadow: 0 2px 10px rgba(0,0,0,0.3);
  transition: all 0.3s ease;
}

.case-item:hover .product-icon {
  background: linear-gradient(135deg, #764ba2 0%, #667eea 100%);
}

.case-item:hover .product-icon i {
  transform: scale(1.1);
  text-shadow: 0 4px 20px rgba(0,0,0,0.4);
}

.case-content {
  padding: 25px;
  position: relative;
}

.case-content:before {
  content: "";
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 50px;
  height: 3px;
  background: var(--gradient-bg);
  border-radius: 1.5px;
}

.case-content h4 {
  font-size: 1.3rem;
  font-weight: 600;
  color: var(--dark-color);
  margin-bottom: 15px;
  transition: var(--transition);
}

.case-item:hover .case-content h4 {
  color: var(--primary-color);
}

.case-content p {
  color: #666;
  font-size: 1rem;
  line-height: 1.7;
}



/* 页脚样式 */
#footer {
  background: linear-gradient(135deg, var(--dark-color), #003366);
  color: var(--light-text);
  padding: 80px 0 30px;
  position: relative;
  overflow: hidden;
}

#footer:before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: url("../images/tech-pattern.svg");
  opacity: 0.05;
  pointer-events: none;
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 50px;
  margin-bottom: 50px;
}

.footer-column h3 {
  font-size: 1.3rem;
  font-weight: 600;
  margin-bottom: 25px;
  position: relative;
  padding-bottom: 15px;
}
.footer-column ul li {
  margin-bottom: 10px;
}

.footer-column h3:after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 40px;
  height: 3px;
  background: var(--gradient-bg);
  border-radius: 1.5px;
}

.footer-column p {
  margin-bottom: 20px;
  line-height: 1.8;
}

.footer-links li {
  margin-bottom: 12px;
}

.footer-links a {
  color: rgba(255, 255, 255, 0.8);
  transition: var(--transition);
  position: relative;
  padding-left: 15px;
}

.footer-links a:before {
  content: "→";
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  font-size: 0.8rem;
  opacity: 0.7;
  transition: var(--transition);
}

.footer-links a:hover {
  color: var(--light-text);
  padding-left: 20px;
}

.footer-links a:hover:before {
  opacity: 1;
}

.contact-info li {
  margin-bottom: 15px;
  display: flex;
  align-items: flex-start;
}

.contact-info i {
  margin-right: 15px;
  font-size: 1.2rem;
  color: var(--secondary-color);
}

.social-links {
  display: flex;
  gap: 15px;
  margin-top: 20px;
}

.social-links a {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 50%;
  color: var(--light-text);
  font-size: 1.2rem;
  transition: var(--transition);
}

.social-links a:hover {
  background: var(--gradient-bg);
  transform: translateY(-5px);
}

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

.footer-bottom p {
  font-size: 0.9rem;
  color: rgba(255, 255, 255, 0.7);
}

/* PC端专用样式 - 移除移动端适配 */
.menu-toggle {
  display: none !important;
}

nav {
  display: flex !important;
}

/* 移除移动端适配样式 */

/* 动画效果 */
.animate-fade-in {
  animation: fadeIn 1s ease-out;
}

.animate-fade-in-up {
  animation: fadeInUp 1s ease-out;
}

.animate-fade-in-left {
  animation: fadeInLeft 1s ease-out;
}

.animate-fade-in-right {
  animation: fadeInRight 1s ease-out;
}

@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeInLeft {
  from {
    opacity: 0;
    transform: translateX(-30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes fadeInRight {
  from {
    opacity: 0;
    transform: translateX(30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

/* 科技感元素 */
.tech-card {
  position: relative;
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: var(--glass-border);
  border-radius: var(--border-radius);
  overflow: hidden;
}

.tech-card:before {
  content: "";
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: linear-gradient(
    45deg,
    transparent,
    rgba(0, 170, 255, 0.1),
    transparent
  );
  transform: rotate(45deg);
  animation: shimmer 3s infinite linear;
  pointer-events: none;
}

@keyframes shimmer {
  0% {
    transform: translateX(-100%) rotate(45deg);
  }
  100% {
    transform: translateX(100%) rotate(45deg);
  }
}

.neon-border {
  position: relative;
}

.neon-border:after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  box-shadow: var(--neon-glow);
  opacity: 0;
  transition: var(--transition);
  pointer-events: none;
  border-radius: inherit;
}

.neon-border:hover:after {
  opacity: 1;
}

.tech-gradient-text {
  background: var(--gradient-bg);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  display: inline-block;
}

.floating {
  animation: floating 3s ease-in-out infinite;
}

@keyframes floating {
  0% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-10px);
  }
  100% {
    transform: translateY(0);
  }
}

/* 鼠标悬停效果 */
.hover-zoom {
  transition: transform 0.5s ease;
}

.hover-zoom:hover {
  transform: scale(1.05);
}

.hover-glow {
  transition: box-shadow 0.3s ease;
}

.hover-glow:hover {
  box-shadow: var(--neon-glow);
}

/* 玻璃态效果 */
.glass-effect {
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: var(--glass-border);
  border-radius: var(--border-radius);
}

/* 类别标题头部样式 */
.category-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 30px;
}
.category-title {
  border-bottom: 3px solid var(--primary-color);
}
/* 更多案例链接样式 */
.more-cases {
  display: inline-flex;
  align-items: center;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--primary-color);
  padding: 5px 10px;
  border-radius: 20px;
  background-color: rgba(var(--primary-rgb), 0.1);
  transition: all 0.3s ease;
  text-decoration: none;
}

.more-cases i {
  margin-right: 5px;
  font-size: 0.8rem;
}

.more-cases:hover {
  background-color: var(--primary-color);
  color: white;
  transform: translateY(-2px);
  box-shadow: 0 4px 8px rgba(var(--primary-rgb), 0.3);
}

/* 移除移动端适配 */

/* 公司介绍样式 */
.company-content {
  margin: 0 auto 100px;
}

.company-intro {
  background: rgba(255, 255, 255, 0.95);
  border-radius: var(--border-radius);
  padding: 40px;
  box-shadow: var(--box-shadow);
  position: relative;
  overflow: hidden;
}

.company-intro:before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: var(--gradient-bg);
}

.intro-highlight {
  font-size: 1.2rem;
  line-height: 1.8;
  color: var(--text-color);
  margin-bottom: 40px;
  position: relative;
  padding: 20px;
  background: rgba(0, 102, 204, 0.05);
  border-radius: var(--border-radius);
  border-left: 4px solid var(--primary-color);
}

.intro-highlight strong {
  color: var(--primary-color);
  font-weight: 600;
}

.company-features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 30px;
  margin-bottom: 40px;
}

.feature-item {
  background: rgba(255, 255, 255, 0.8);
  padding: 25px;
  border-radius: var(--border-radius);
  border: 1px solid rgba(0, 102, 204, 0.1);
  transition: var(--transition);
  position: relative;
}

.feature-item:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 25px rgba(0, 102, 204, 0.15);
  border-color: var(--primary-color);
}

.feature-item h4 {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--dark-color);
  margin-bottom: 15px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.feature-item h4 i {
  color: var(--primary-color);
  font-size: 1.2rem;
}

.feature-item p {
  color: #666;
  line-height: 1.7;
  font-size: 0.95rem;
}

.company-cta {
  text-align: center;
  padding-top: 20px;
  border-top: 1px solid rgba(0, 102, 204, 0.1);
}

.company-cta .btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 1rem;
  padding: 15px 35px;
}

.company-cta .btn i {
  transition: transform 0.3s ease;
}

.company-cta .btn:hover i {
  transform: translateX(5px);
}

/* 移除移动端适配 */

/* 返回顶部按钮样式 */
.back-to-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 50px;
  height: 50px;
  background: var(--gradient-bg);
  color: var(--light-text);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
  transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
  border: none;
  box-shadow: 0 4px 15px rgba(0, 102, 204, 0.4);
  z-index: 999;
}

.back-to-top:before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    135deg,
    var(--secondary-color),
    var(--primary-color)
  );
  border-radius: 50%;
  z-index: -1;
  opacity: 0;
  transition: var(--transition);
}

.back-to-top:hover:before {
  opacity: 1;
}

.back-to-top:hover {
  transform: translateY(-5px) scale(1.05);
  box-shadow: 0 8px 25px rgba(0, 102, 204, 0.5), var(--neon-glow);
}

.back-to-top.clicked {
  animation: pulse 0.3s ease-out;
}

@keyframes pulse {
  0% {
    transform: scale(1);
  }
  50% {
    transform: scale(0.85);
  }
  100% {
    transform: scale(1);
  }
}

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

.back-to-top i {
  transition: transform 0.3s ease;
  position: relative;
  z-index: 2;
}

.back-to-top:hover i {
  transform: translateY(-3px);
}

.back-to-top-circle {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 100%;
  height: 100%;
  border-radius: 50%;
  background: transparent;
  border: 2px solid rgba(255, 255, 255, 0.2);
  z-index: 1;
}

.back-to-top-circle:after {
  content: "";
  position: absolute;
  top: -2px;
  left: -2px;
  width: calc(100% + 4px);
  height: calc(100% + 4px);
  border-radius: 50%;
  border: 2px solid transparent;
  border-top-color: var(--accent-color);
  animation: spin 1.5s linear infinite;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.back-to-top:hover .back-to-top-circle:after {
  opacity: 1;
}

@keyframes spin {
  0% {
    transform: rotate(0deg);
  }
  100% {
    transform: rotate(360deg);
  }
}

/* 移除移动端适配 */