/* ============================================
   湖北楚海能源有限公司 - 主样式表
   深色科技感 + 蓝光效果主题 v2.0
   ============================================ */

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

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

body {
  font-family: var(--font-family);
  background-color: var(--bg-primary);
  color: var(--color-text-primary);
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* 页面加载 */
body.preload { opacity: 0; }
body.loaded { opacity: 1; transition: opacity 0.6s ease; }

a { color: inherit; text-decoration: none; transition: color var(--transition-fast); }
img { max-width: 100%; display: block; }
ul, ol { list-style: none; }

/* ---- 通用容器 ---- */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: var(--container-padding);
}

/* ---- 区块标题 ---- */
.section-header {
  text-align: center;
  margin-bottom: 60px;
}

.section-tag {
  display: inline-block;
  font-size: var(--font-size-xs);
  font-weight: 600;
  letter-spacing: 3px;
  color: var(--color-primary);
  margin-bottom: 12px;
}

.section-title {
  font-size: var(--font-size-4xl);
  font-weight: 700;
  color: var(--color-text-primary);
  margin-bottom: 16px;
}

.gradient-text {
  background: var(--gradient-text);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.section-desc {
  font-size: var(--font-size-lg);
  color: var(--color-text-secondary);
  max-width: 600px;
  margin: 0 auto;
}

.section-divider {
  width: 80px;
  height: 3px;
  background: var(--gradient-primary);
  margin: 20px auto 0;
  border-radius: var(--radius-full);
}

/* ---- 滚动入场动画 ---- */
.fade-up {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

.fade-up.visible {
  opacity: 1;
  transform: translateY(0);
}

.fade-left {
  opacity: 0;
  transform: translateX(-40px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

.fade-left.visible {
  opacity: 1;
  transform: translateX(0);
}

.fade-right {
  opacity: 0;
  transform: translateX(40px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

.fade-right.visible {
  opacity: 1;
  transform: translateX(0);
}

/* ============================================
   导航栏
   ============================================ */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: var(--z-nav);
  padding: 20px 0;
  transition: all var(--transition-base);
}

.navbar.scrolled {
  padding: 12px 0;
  background: var(--bg-nav);
  backdrop-filter: blur(var(--glass-blur));
  -webkit-backdrop-filter: blur(var(--glass-blur));
  border-bottom: var(--glass-border);
  box-shadow: var(--shadow-lg);
}

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

/* Logo */
.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  z-index: var(--z-nav);
}

.logo-icon {
  flex-shrink: 0;
}

.logo-text {
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: var(--color-text-primary);
}

/* 导航链接 */
.nav-links {
  display: flex;
  align-items: center;
  gap: 36px;
}

.nav-link {
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-text-secondary);
  position: relative;
  padding: 4px 0;
  transition: color var(--transition-fast);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--gradient-primary);
  border-radius: var(--radius-full);
  transition: width var(--transition-base);
}

.nav-link:hover,
.nav-link.active {
  color: var(--color-text-primary);
}

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

/* CTA按钮 */
.nav-cta {
  display: inline-flex;
  align-items: center;
  padding: 8px 20px;
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--color-text-primary);
  background: var(--gradient-primary);
  border-radius: var(--radius-full);
  transition: box-shadow var(--transition-base), transform var(--transition-fast);
}

.nav-cta:hover {
  box-shadow: 0 0 20px var(--glow-primary), 0 0 40px rgba(0, 212, 255, 0.1);
  transform: translateY(-1px);
}

/* 汉堡菜单 */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  background: none;
  border: none;
  padding: 4px;
  z-index: var(--z-nav);
}

.hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text-primary);
  border-radius: 2px;
  transition: all var(--transition-base);
}

.hamburger.active span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
.hamburger.active span:nth-child(2) { opacity: 0; }
.hamburger.active span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

/* ============================================
   Hero 首屏区
   ============================================ */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  background: var(--bg-primary);
}

/* 蓝色光晕背景 */
.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: var(--gradient-hero-glow);
  z-index: 1;
}

/* 网格线背景 */
.hero::after {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(0, 212, 255, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 212, 255, 0.03) 1px, transparent 1px);
  background-size: 60px 60px;
  z-index: 1;
}

/* 粒子 */
.particles {
  position: absolute;
  inset: 0;
  z-index: 1;
  overflow: hidden;
}

.particles span {
  position: absolute;
  width: 3px;
  height: 3px;
  background: var(--color-primary);
  border-radius: 50%;
  opacity: 0;
  animation: particleFloat 6s infinite ease-in-out;
}

/* 40个粒子的随机位置和延迟 */
.particles span:nth-child(1)  { left: 5%;  top: 20%; animation-delay: 0s; animation-duration: 8s; }
.particles span:nth-child(2)  { left: 15%; top: 60%; animation-delay: 0.5s; animation-duration: 7s; }
.particles span:nth-child(3)  { left: 25%; top: 10%; animation-delay: 1s; animation-duration: 9s; }
.particles span:nth-child(4)  { left: 35%; top: 80%; animation-delay: 1.5s; animation-duration: 6s; }
.particles span:nth-child(5)  { left: 45%; top: 40%; animation-delay: 2s; animation-duration: 8s; }
.particles span:nth-child(6)  { left: 55%; top: 15%; animation-delay: 0.3s; animation-duration: 7s; }
.particles span:nth-child(7)  { left: 65%; top: 70%; animation-delay: 1.8s; animation-duration: 9s; }
.particles span:nth-child(8)  { left: 75%; top: 30%; animation-delay: 0.7s; animation-duration: 6s; }
.particles span:nth-child(9)  { left: 85%; top: 55%; animation-delay: 2.3s; animation-duration: 8s; }
.particles span:nth-child(10) { left: 95%; top: 25%; animation-delay: 1.2s; animation-duration: 7s; }
.particles span:nth-child(11) { left: 10%; top: 45%; animation-delay: 0.8s; animation-duration: 10s; }
.particles span:nth-child(12) { left: 20%; top: 85%; animation-delay: 2.5s; animation-duration: 6s; }
.particles span:nth-child(13) { left: 30%; top: 25%; animation-delay: 0.2s; animation-duration: 8s; }
.particles span:nth-child(14) { left: 40%; top: 65%; animation-delay: 1.6s; animation-duration: 9s; }
.particles span:nth-child(15) { left: 50%; top: 5%;  animation-delay: 3s; animation-duration: 7s; }
.particles span:nth-child(16) { left: 60%; top: 50%; animation-delay: 0.4s; animation-duration: 6s; }
.particles span:nth-child(17) { left: 70%; top: 90%; animation-delay: 2.1s; animation-duration: 8s; }
.particles span:nth-child(18) { left: 80%; top: 10%; animation-delay: 1.3s; animation-duration: 10s; }
.particles span:nth-child(19) { left: 90%; top: 75%; animation-delay: 0.6s; animation-duration: 7s; }
.particles span:nth-child(20) { left: 3%;  top: 50%; animation-delay: 2.8s; animation-duration: 9s; }
.particles span:nth-child(21) { left: 18%; top: 35%; animation-delay: 1.1s; animation-duration: 6s; }
.particles span:nth-child(22) { left: 28%; top: 70%; animation-delay: 0.9s; animation-duration: 8s; }
.particles span:nth-child(23) { left: 38%; top: 15%; animation-delay: 2.6s; animation-duration: 7s; }
.particles span:nth-child(24) { left: 48%; top: 55%; animation-delay: 0.1s; animation-duration: 10s; }
.particles span:nth-child(25) { left: 58%; top: 35%; animation-delay: 1.9s; animation-duration: 6s; }
.particles span:nth-child(26) { left: 68%; top: 85%; animation-delay: 3.2s; animation-duration: 9s; }
.particles span:nth-child(27) { left: 78%; top: 20%; animation-delay: 0.5s; animation-duration: 8s; }
.particles span:nth-child(28) { left: 88%; top: 45%; animation-delay: 2.2s; animation-duration: 7s; }
.particles span:nth-child(29) { left: 8%;  top: 90%; animation-delay: 1.4s; animation-duration: 10s; }
.particles span:nth-child(30) { left: 22%; top: 50%; animation-delay: 0.7s; animation-duration: 6s; }
.particles span:nth-child(31) { left: 33%; top: 40%; animation-delay: 2.4s; animation-duration: 8s; }
.particles span:nth-child(32) { left: 43%; top: 95%; animation-delay: 1s; animation-duration: 9s; }
.particles span:nth-child(33) { left: 53%; top: 28%; animation-delay: 3.5s; animation-duration: 7s; }
.particles span:nth-child(34) { left: 63%; top: 62%; animation-delay: 0.3s; animation-duration: 6s; }
.particles span:nth-child(35) { left: 73%; top: 8%;  animation-delay: 2.7s; animation-duration: 10s; }
.particles span:nth-child(36) { left: 83%; top: 82%; animation-delay: 1.7s; animation-duration: 8s; }
.particles span:nth-child(37) { left: 92%; top: 38%; animation-delay: 0.9s; animation-duration: 7s; }
.particles span:nth-child(38) { left: 12%; top: 72%; animation-delay: 3.1s; animation-duration: 9s; }
.particles span:nth-child(39) { left: 42%; top: 48%; animation-delay: 0.6s; animation-duration: 6s; }
.particles span:nth-child(40) { left: 72%; top: 18%; animation-delay: 2s; animation-duration: 8s; }

@keyframes particleFloat {
  0%, 100% { opacity: 0; transform: translateY(0) scale(1); }
  20% { opacity: 0.8; }
  50% { opacity: 0.4; transform: translateY(-80px) scale(1.5); }
  80% { opacity: 0.6; }
}

/* Hero 内容 */
.hero-content {
  position: relative;
  z-index: 2;
  text-align: center;
  padding: 0 20px;
}

.hero-title {
  font-size: var(--font-size-5xl);
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 24px;
  color: var(--color-text-primary);
}

.hero-subtitle {
  font-size: var(--font-size-xl);
  color: var(--color-text-secondary);
  max-width: 650px;
  margin: 0 auto 40px;
  line-height: 1.8;
  text-shadow: 0 0 30px var(--glow-primary);
}

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

/* 向下滚动箭头 */
.scroll-arrow {
  position: absolute;
  bottom: 40px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 2;
  color: var(--color-text-muted);
  animation: bounceArrow 2s infinite;
}

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

/* ============================================
   按钮系统
   ============================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 32px;
  font-size: var(--font-size-base);
  font-weight: 600;
  font-family: var(--font-family);
  border-radius: var(--radius-full);
  border: none;
  cursor: pointer;
  transition: all var(--transition-base);
  text-decoration: none;
}

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

.btn-primary:hover {
  box-shadow: 0 0 25px var(--glow-primary), 0 0 50px rgba(0, 212, 255, 0.15);
  transform: translateY(-2px);
  color: var(--bg-primary);
}

.btn-outline {
  background: transparent;
  color: var(--color-text-primary);
  border: 1px solid var(--border-color);
}

.btn-outline:hover {
  border-color: var(--color-primary);
  background: rgba(0, 212, 255, 0.08);
  color: var(--color-primary);
  box-shadow: 0 0 20px rgba(0, 212, 255, 0.1);
}

/* ============================================
   数据统计区
   ============================================ */
.stats {
  padding: 80px 0;
  position: relative;
  background: var(--bg-secondary);
  border-top: var(--glass-border);
  border-bottom: var(--glass-border);
}

.stats::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(0, 212, 255, 0.02) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 212, 255, 0.02) 1px, transparent 1px);
  background-size: 40px 40px;
  pointer-events: none;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  position: relative;
}

.stat-card {
  text-align: center;
  padding: 32px 20px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  transition: all var(--transition-base);
}

.stat-card:hover {
  border-color: var(--border-color-hover);
  box-shadow: var(--shadow-glow);
  transform: translateY(-4px);
}

.stat-number {
  font-size: var(--font-size-5xl);
  font-weight: 700;
  background: var(--gradient-text);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1.2;
}

.stat-suffix {
  font-size: var(--font-size-2xl);
  font-weight: 700;
  background: var(--gradient-text);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.stat-label {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  margin-top: 8px;
}

/* ============================================
   解决方案区块
   ============================================ */
.business {
  padding: var(--section-padding);
}

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

.business-card {
  padding: 36px 28px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  transition: all var(--transition-base);
}

.business-card:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-color-hover);
  box-shadow: var(--shadow-glow);
  transform: translateY(-8px);
}

.business-icon {
  width: 60px;
  height: 60px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--gradient-primary);
  border-radius: var(--radius-md);
  margin-bottom: 20px;
  transition: box-shadow var(--transition-base);
}

.business-card:hover .business-icon {
  box-shadow: 0 0 20px var(--glow-primary);
}

.business-card h3 {
  font-size: var(--font-size-xl);
  font-weight: 600;
  margin-bottom: 12px;
  color: var(--color-text-primary);
}

.business-card p {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  line-height: 1.7;
}

/* ============================================
   关于我们
   ============================================ */
.about {
  padding: var(--section-padding);
  background: var(--bg-secondary);
}

.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

/* 图片占位区域 */
.about-image {
  position: relative;
}

.about-visual {
  width: 100%;
  aspect-ratio: 4/3;
  background: linear-gradient(135deg, rgba(0,136,255,0.15), rgba(0,212,255,0.05));
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

/* 占位区域装饰光效 */
.about-visual::before {
  content: '';
  position: absolute;
  width: 200px;
  height: 200px;
  background: radial-gradient(circle, var(--glow-primary), transparent 70%);
  border-radius: 50%;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}

.about-visual-icon {
  position: relative;
  z-index: 1;
  opacity: 0.8;
}

/* 右侧内容 */
.about-content .section-tag {
  display: inline-block;
}

.about-content .section-title {
  text-align: left;
  margin-bottom: 20px;
}

.about-desc {
  font-size: var(--font-size-base);
  color: var(--color-text-secondary);
  line-height: 1.8;
  margin-bottom: 28px;
}

.about-features {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 32px;
}

.about-features li {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: var(--font-size-base);
  color: var(--color-text-secondary);
}

.about-features li svg {
  flex-shrink: 0;
}

/* ============================================
   业务范围
   ============================================ */
.services {
  padding: var(--section-padding);
}

.services-list {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.service-item {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 28px;
  padding: 32px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  transition: all var(--transition-base);
}

.service-item:hover {
  border-color: var(--border-color-hover);
  box-shadow: var(--shadow-glow);
}

.service-icon {
  width: 64px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0, 212, 255, 0.08);
  border: 1px solid rgba(0, 212, 255, 0.2);
  border-radius: var(--radius-md);
  color: var(--color-primary);
  flex-shrink: 0;
}

.service-content h3 {
  font-size: var(--font-size-xl);
  font-weight: 600;
  margin-bottom: 12px;
  color: var(--color-text-primary);
}

.service-content p {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  line-height: 1.8;
  margin-bottom: 16px;
}

.service-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.service-tag {
  padding: 4px 14px;
  font-size: var(--font-size-xs);
  color: var(--color-primary);
  background: rgba(0, 212, 255, 0.08);
  border: 1px solid rgba(0, 212, 255, 0.2);
  border-radius: var(--radius-full);
}

/* ============================================
   联系我们
   ============================================ */
.contact {
  padding: var(--section-padding);
  background: var(--bg-secondary);
}

.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: start;
}

/* 表单 */
.contact-form h3,
.contact-info h3 {
  font-size: var(--font-size-2xl);
  font-weight: 600;
  margin-bottom: 24px;
  color: var(--color-text-primary);
}

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

.form-label {
  display: block;
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-text-secondary);
  margin-bottom: 8px;
}

.form-input,
.form-textarea {
  width: 100%;
  padding: 12px 16px;
  font-size: var(--font-size-base);
  font-family: var(--font-family);
  color: var(--color-text-primary);
  background: var(--bg-input);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  outline: none;
  transition: all var(--transition-base);
}

.form-input:focus,
.form-textarea:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(0, 212, 255, 0.1), 0 0 20px rgba(0, 212, 255, 0.08);
}

.form-input::placeholder,
.form-textarea::placeholder {
  color: var(--color-text-muted);
}

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

.form-submit {
  width: 100%;
  padding: 14px;
  font-size: var(--font-size-base);
  font-weight: 600;
  font-family: var(--font-family);
  color: var(--bg-primary);
  background: var(--gradient-primary);
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-base);
}

.form-submit:hover {
  box-shadow: 0 0 25px var(--glow-primary), 0 0 50px rgba(0, 212, 255, 0.15);
  transform: translateY(-2px);
}

/* 联系信息 */
.contact-info-list {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.contact-item {
  display: flex;
  gap: 16px;
  align-items: flex-start;
}

.contact-icon {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0, 212, 255, 0.08);
  border: 1px solid rgba(0, 212, 255, 0.2);
  border-radius: var(--radius-md);
  color: var(--color-primary);
  flex-shrink: 0;
}

.contact-detail h4 {
  font-size: var(--font-size-base);
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: 4px;
}

.contact-detail p {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
}

/* ============================================
   页脚
   ============================================ */
.footer {
  background: var(--bg-footer);
  padding-top: 80px;
}

.footer-divider {
  height: 1px;
  background: var(--gradient-divider);
}

.footer-content {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 48px;
  padding: 60px 0 40px;
}

.footer-brand h3 {
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: var(--color-text-primary);
  margin-bottom: 16px;
}

.footer-brand p {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  line-height: 1.8;
}

.footer-links h4 {
  font-size: var(--font-size-base);
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: 20px;
}

.footer-links ul {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-links a,
.footer-links li {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  transition: color var(--transition-fast);
}

.footer-links a:hover {
  color: var(--color-primary);
}

.footer-bottom {
  padding: 24px 0;
  border-top: var(--glass-border);
  text-align: center;
}

.footer-bottom p {
  font-size: var(--font-size-xs);
  color: var(--color-text-muted);
}

/* ============================================
   返回顶部
   ============================================ */
.back-to-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--gradient-primary);
  border: none;
  border-radius: 50%;
  color: var(--bg-primary);
  cursor: pointer;
  z-index: var(--z-back-top);
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
  transition: all var(--transition-base);
  box-shadow: 0 4px 16px rgba(0, 136, 255, 0.3);
}

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

.back-to-top:hover {
  box-shadow: 0 0 25px var(--glow-primary), 0 0 50px rgba(0, 212, 255, 0.15);
  transform: translateY(-3px);
}