/* 기본 리셋 & CSS 변수 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --primary-color: #1e69ff;
  --primary-dark: #0047cc;
  --secondary-color: #00d4ff;
  --accent-color: #ff6b35;
  --text-dark: #1a1a2e;
  --text-light: #666;
  --bg-light: #f8f9fa;
  --white: #ffffff;
  --gradient-1: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --gradient-2: linear-gradient(135deg, #1e69ff 0%, #00d4ff 100%);
  --gradient-3: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.12);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.15);
  --transition: all 0.3s ease;
}

* {
  box-sizing: border-box;
}

html {
  overflow-x: hidden;
  max-width: 100vw;
}

body {
  font-family: "Noto Sans KR", "Roboto", sans-serif;
  color: var(--text-dark);
  line-height: 1.6;
  overflow-x: hidden;
  max-width: 100vw;
  width: 100%;
}

.container {
  max-width: 1200px;
  width: 100%;
  margin: 0 auto;
  padding: 0 20px;
}

/* 네비게이션 */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background: transparent;
  z-index: 1000;
  transition: var(--transition);
  padding: 20px 0;
}

.navbar.scrolled {
  background: rgba(255, 255, 255, 0.98);
  box-shadow: var(--shadow-md);
  padding: 15px 0;
  backdrop-filter: blur(10px);
}

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

.logo {
  text-decoration: none;
  display: flex;
  align-items: center;
}

.logo-img {
  height: 80px;
  width: auto;
  max-width: 300px;
  transition: var(--transition);
  filter: brightness(0) invert(1);
}

.navbar.scrolled .logo-img {
  filter: none;
  height: 75px;
}

.logo-text {
  font-size: 28px;
  font-weight: 700;
  color: var(--white);
  letter-spacing: 1px;
  transition: var(--transition);
}

.navbar.scrolled .logo-text {
  color: var(--text-dark);
}

.logo-text .highlight {
  background: var(--gradient-2);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-menu {
  display: flex;
  list-style: none;
  gap: 35px;
  align-items: center;
}

.nav-link {
  color: var(--white);
  text-decoration: none;
  font-weight: 500;
  font-size: 15px;
  position: relative;
  transition: var(--transition);
}

.navbar.scrolled .nav-link {
  color: var(--text-dark);
}

.nav-link::after {
  content: "";
  position: absolute;
  bottom: -5px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--gradient-2);
  transition: var(--transition);
}

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

.language-dropdown {
  position: relative;
}

.nav-link.language {
  padding: 8px 20px;
  border: 2px solid var(--white);
  border-radius: 25px;
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
}

.navbar.scrolled .nav-link.language {
  border-color: var(--primary-color);
}

.nav-link.language:hover {
  background: var(--gradient-2);
  color: var(--white);
  border-color: transparent;
}

.language-menu {
  position: absolute;
  top: 100%;
  right: 0;
  margin-top: 10px;
  background: var(--white);
  border-radius: 12px;
  box-shadow: var(--shadow-lg);
  list-style: none;
  padding: 10px 0;
  min-width: 150px;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-10px);
  transition: var(--transition);
  z-index: 1000;
}

.language-dropdown:hover .language-menu,
.language-menu:hover {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.language-menu li {
  list-style: none;
}

.language-menu a {
  display: block;
  padding: 10px 20px;
  color: var(--text-dark);
  text-decoration: none;
  transition: var(--transition);
  font-size: 14px;
}

.language-menu a:hover {
  background: var(--bg-light);
  color: var(--primary-color);
}

.language-menu a::after {
  display: none;
}

.hamburger {
  display: none;
  flex-direction: column;
  cursor: pointer;
  gap: 5px;
  position: relative;
  z-index: 1002;
}

.hamburger span {
  width: 25px;
  height: 3px;
  background: var(--white);
  border-radius: 3px;
  transition: var(--transition);
  display: block;
}

.navbar.scrolled .hamburger span {
  background: var(--primary-color); /* 파란색으로 변경 - 더 잘 보임 */
}

.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(7px, -7px);
}

/* 메인 히어로 섹션 */
.hero {
  position: relative;
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  background: linear-gradient(135deg, #1e3c72 0%, #2a5298 50%, #764ba2 100%);
}

.hero-video {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  overflow: hidden;
  z-index: 0;
}

.hero-video video {
  position: absolute;
  top: 50%;
  left: 50%;
  min-width: 100%;
  min-height: 100%;
  width: auto;
  height: auto;
  transform: translate(-50%, -50%);
  object-fit: cover;
}

/* 기본: PC/태블릿에서는 2열 */
.battery-features-grid {
  display: grid;
  grid-template-columns: repeat(1, 1fr);
  gap: 2px;
}

/* 05번 BMS는 항상 전체 폭 (1~2열 통합) */
.battery-features-grid > div:last-child {
  grid-column: 1 / -1;
}

.bms-section {
  grid-column: 1 / -1; /* PC에서 전체 폭 */
}

.battery-cells-wrapper {
  margin-bottom: 60px;
}

.battery-cells-title {
  text-align: center;
  font-size: 14px;
  font-weight: 600;
  color: #666;
  margin-bottom: 25px;
  letter-spacing: 3px;
  text-transform: uppercase;
}

.battery-cells-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 2px;
  background: #edeef0;
  max-width: 1000px;
  margin: 0 auto;
}

.battery-cells-grid img {
  max-height: 45px;
  max-width: 180px;
  width: auto;
  height: auto;
  object-fit: contain;
  display: block;
  margin: 40px auto;
}
.battery-section {
  padding: 60px 20px;
  /* background: radial-gradient(circle at top left, #123e72 0, #060e1a 55%, #020509 100%); */
  display: flex;
  justify-content: center;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Noto Sans KR", "Segoe UI", sans-serif;
  color: #e6f0ff;
}

.battery-inner {
  max-width: 1200px;
  width: 100%;
  display: flex;
  gap: 32px;
  align-items: stretch;
}

/* 왼쪽 비주얼 영역 */
.battery-left {
  flex: 1.1;
  border-radius: 20px;
  overflow: hidden;
  position: relative;
  background-image: linear-gradient(135deg, rgba(0, 255, 255, 0.22), rgba(0, 170, 255, 0.05)), url("/images/battery.jpg");
  /* ↑ 임시 프리소스 이미지, 실제 배터리 일러스트로 교체해도 됨 */
  background-size: cover;
  background-position: center;
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.6);
}

.battery-visual-overlay {
  position: relative;
  z-index: 1;
  padding: 32px 28px;
  height: 100%;
  background: linear-gradient(145deg, rgba(2, 12, 30, 0.9) 0, rgba(2, 14, 40, 0.55) 45%, rgba(0, 0, 0, 0.15) 100%);
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
}

.battery-tagline {
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  opacity: 0.85;
  margin-bottom: 10px;
}

.battery-title-en {
  font-size: 34px;
  line-height: 1.1;
  font-weight: 800;
  margin-bottom: 14px;
}

.battery-caption {
  font-size: 13px;
  opacity: 0.85;
}

/* 오른쪽 내용 영역 */
.battery-right {
  flex: 1;
  background: linear-gradient(145deg, #071526, #06121f);
  border-radius: 20px;
  padding: 28px 30px 26px;
  box-shadow: 0 24px 50px rgba(0, 0, 0, 0.55);
  border: 1px solid rgba(124, 178, 255, 0.25);
  display: flex;
  flex-direction: column;
}

.battery-heading {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 20px;
  letter-spacing: -0.03em;
}

.battery-table-wrap {
  border-radius: 14px;
  border: 1px solid rgba(120, 180, 255, 0.5);
  overflow: hidden;
  background: radial-gradient(circle at top, #0e2644, #050d19);
  margin-bottom: 18px;
}

.battery-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
}

.battery-table thead {
  background: linear-gradient(90deg, #163a66, #144f7a);
}

.battery-table th,
.battery-table td {
  padding: 10px 14px;
  border-bottom: 1px solid rgba(120, 180, 255, 0.2);
  text-align: left;
}

.battery-table th:first-child,
.battery-table td:first-child {
  width: 27%;
  border-right: 1px solid rgba(120, 180, 255, 0.24);
}

.battery-table th {
  font-weight: 600;
  font-size: 13px;
  color: #eaf2ff;
  white-space: nowrap;
}

.battery-table tbody tr:nth-child(even) {
  background-color: rgba(8, 24, 48, 0.65);
}

.battery-table tbody tr:nth-child(odd) {
  background-color: rgba(5, 16, 32, 0.85);
}

.battery-desc {
  margin-top: auto;
  font-size: 13px;
  line-height: 1.7;
  color: #b7c7e7;
}

@media (max-width: 960px) {
  .battery-inner {
    flex-direction: column;
  }

  .battery-left,
  .battery-right {
    flex: none;
    width: 100%;
  }
}

/* 모바일에서 비디오 최적화 */
@media (max-width: 768px) {
  .battery-section {
    padding: 40px 16px;
  }

  .battery-right {
    padding: 22px 18px 20px;
  }

  .battery-heading {
    font-size: 18px;
  }

  .battery-table th,
  .battery-table td {
    padding: 8px 10px;
    font-size: 12px;
  }

  .battery-title-en {
    font-size: 26px;
  }

  .hero-video video {
    display: block; /* 모바일에서도 비디오 표시 */
  }
  .battery-features-grid {
    grid-template-columns: 1fr;
  }

  /* 모바일에서도 전체 폭 (1열이면 자동이지만 명시) */
  .bms-section {
    grid-column: 1 / -1;
  }
}

.hero-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.5);
  z-index: 1;
}

.hero-background {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  overflow: hidden;
  z-index: 0;
  pointer-events: none;
}

.particles {
  position: absolute;
  width: 100%;
  height: 100%;
  background-image: radial-gradient(2px 2px at 20% 30%, white, transparent), radial-gradient(2px 2px at 60% 70%, white, transparent), radial-gradient(1px 1px at 50% 50%, white, transparent),
    radial-gradient(1px 1px at 80% 10%, white, transparent), radial-gradient(2px 2px at 90% 60%, white, transparent), radial-gradient(1px 1px at 33% 80%, white, transparent),
    radial-gradient(2px 2px at 10% 90%, white, transparent);
  background-size: 200% 200%;
  animation: moveParticles 20s linear infinite;
}

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

.hero-content {
  position: relative;
  z-index: 2;
  text-align: center;
  color: var(--white);
  max-width: 900px;
  margin: 0 auto;
  width: 100%;
}

.hero-title {
  font-size: 52px;
  font-weight: 700;
  margin-bottom: 30px;
  line-height: 1.2;
  text-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

.gradient-text {
  background: linear-gradient(90deg, #00d4ff, #00ffaa, #00d4ff);
  background-size: 200% auto;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: gradientShift 3s linear infinite;
}

@keyframes gradientShift {
  0% {
    background-position: 0% center;
  }
  100% {
    background-position: 200% center;
  }
}

.hero-features {
  margin: 40px 0;
  display: flex;
  flex-direction: column;
  gap: 15px;
  text-align: left;
  max-width: 700px;
  margin-left: auto;
  margin-right: auto;
}

.feature-item {
  display: flex;
  align-items: center;
  gap: 15px;
  font-size: 18px;
  font-weight: 500;
}

.feature-item i {
  color: #00ffaa;
  font-size: 20px;
}

.hero-buttons {
  display: flex;
  gap: 20px;
  justify-content: center;
  margin-top: 50px;
}

.btn {
  padding: 15px 40px;
  border-radius: 50px;
  text-decoration: none;
  font-weight: 600;
  font-size: 16px;
  transition: var(--transition);
  display: inline-flex;
  align-items: center;
  gap: 10px;
  cursor: pointer;
  border: none;
}

.btn-primary {
  background: var(--gradient-2);
  color: var(--white);
  box-shadow: 0 4px 20px rgba(30, 105, 255, 0.4);
}

.btn-primary:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 30px rgba(30, 105, 255, 0.6);
}

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

.btn-outline:hover {
  background: var(--white);
  color: var(--primary-color);
  transform: translateY(-3px);
}

.scroll-indicator {
  position: absolute;
  bottom: 40px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 15px;
  color: var(--white);
  z-index: 2;
}

.mouse-scroll {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
}

.mouse {
  width: 30px;
  height: 50px;
  border: 3px solid var(--white);
  border-radius: 20px;
  position: relative;
  animation: mouseFloat 2s ease-in-out infinite;
}

.wheel {
  width: 4px;
  height: 10px;
  background: var(--white);
  border-radius: 2px;
  position: absolute;
  top: 10px;
  left: 50%;
  transform: translateX(-50%);
  animation: wheelScroll 2s ease-in-out infinite;
}

.arrow-down {
  display: flex;
  flex-direction: column;
  gap: 3px;
  align-items: center;
}

.arrow-down span {
  display: block;
  width: 12px;
  height: 2px;
  background: var(--white);
  border-radius: 2px;
  animation: arrowMove 2s ease-in-out infinite;
}

.arrow-down span:nth-child(1) {
  transform: rotate(45deg) translateX(-3px);
  animation-delay: 0s;
}

.arrow-down span:nth-child(2) {
  transform: rotate(-45deg) translateX(3px);
  margin-top: -2px;
  animation-delay: 0.1s;
}

.arrow-down span:nth-child(3) {
  width: 2px;
  height: 12px;
  animation-delay: 0.2s;
}

.scroll-text {
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 2px;
  font-weight: 500;
}

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

@keyframes wheelScroll {
  0%,
  100% {
    top: 10px;
    opacity: 1;
  }
  50% {
    top: 25px;
    opacity: 0;
  }
}

@keyframes arrowMove {
  0%,
  100% {
    opacity: 0.4;
    transform: translateY(0);
  }
  50% {
    opacity: 1;
    transform: translateY(5px);
  }
}

/* 공통 섹션 스타일 */
section {
  padding: 100px 0;
  width: 100%;
  max-width: 100vw;
  overflow-x: hidden;
}

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

.section-subtitle {
  display: inline-block;
  color: var(--primary-color);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 2px;
  margin-bottom: 15px;
  font-size: 14px;
}

.section-title {
  font-size: 42px;
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: 20px;
}

/* 회사소개 섹션 */
.about {
  background: linear-gradient(rgba(255, 255, 255, 0.5), rgba(255, 255, 255, 0.88)), url("images/company/NovaEnergy_Company.jpeg") center/cover no-repeat fixed;
  position: relative;
}

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

.about-text h3 {
  font-size: 28px;
  margin-bottom: 20px;
  color: #1a202c;
  font-weight: 700;
}

.about-text p {
  font-size: 16px;
  color: #2d3748;
  margin-bottom: 20px;
  line-height: 1.8;
  font-weight: 500;
}

.about-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
  margin-top: 40px;
}

.stat-item {
  text-align: center;
  padding: 30px;
  background: var(--white);
  border-radius: 15px;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

.stat-item:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-md);
}

.stat-number {
  font-size: 48px;
  font-weight: 700;
  background: var(--gradient-2);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 10px;
}

.stat-label {
  color: var(--text-light);
  font-size: 14px;
  font-weight: 500;
}

.about-image {
  position: relative;
}

.image-wrapper {
  position: relative;
  border-radius: 20px;
  overflow: hidden;
  box-shadow: var(--shadow-lg);
}

.factory-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  aspect-ratio: 4/3;
  border-radius: 20px;
}

.image-placeholder {
  aspect-ratio: 4/3;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  color: var(--white);
}

.image-placeholder i {
  font-size: 80px;
  margin-bottom: 20px;
  opacity: 0.8;
}

.image-placeholder p {
  font-size: 18px;
  font-weight: 500;
}

/* 제품 상세 페이지 이미지 스타일 */
.product-image-wrapper {
  position: relative;
  width: 100%;
  aspect-ratio: 4/3;
  border-radius: 20px;
  overflow: hidden;
  background: #f8f9fa;
}

.product-main-img {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: contain;
  opacity: 0;
  transition: opacity 0.3s ease;
  z-index: 2;
}

.product-main-img.loaded {
  opacity: 1;
}

.product-image-wrapper .image-placeholder {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 1;
  border-radius: 20px;
}

.main-image {
  width: 100%;
  margin-bottom: 20px;
}

.product-gallery {
  position: sticky;
  top: 100px;
}

/* 기술 섹션 */
.tech-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
}

.tech-card {
  background: rgba(255, 255, 255, 0.95);
  border-radius: 20px;
  padding: 40px;
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.3);
  transition: var(--transition);
  position: relative;
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.2);
  backdrop-filter: blur(10px);
}

.tech-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: var(--gradient-2);
  transform: scaleX(0);
  transition: var(--transition);
}

.tech-card:hover::before {
  transform: scaleX(1);
}

.tech-card:hover {
  transform: translateY(-10px);
  box-shadow: 0 15px 50px rgba(0, 0, 0, 0.2);
}

.tech-card.highlighted {
  background: linear-gradient(135deg, #1e69ff 0%, #00d4ff 100%);
  color: var(--white);
  position: relative;
  box-shadow: 0 8px 40px rgba(30, 105, 255, 0.4);
}

.tech-card.highlighted h3,
.tech-card.highlighted p,
.tech-card.highlighted li {
  color: var(--white);
}

.featured-badge {
  position: absolute;
  top: 20px;
  right: 20px;
  background: rgba(255, 255, 255, 0.2);
  backdrop-filter: blur(10px);
  padding: 5px 15px;
  border-radius: 20px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 1px;
}

.tech-icon {
  width: 180px;
  height: 180px;
  background: var(--gradient-2);
  border-radius: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 25px;
}

.tech-card.highlighted .tech-icon {
  background: rgba(255, 255, 255, 0.2);
}

.tech-icon i {
  font-size: 36px;
  color: var(--white);
}

.tech-card h3 {
  font-size: 24px;
  margin-bottom: 15px;
  font-weight: 700;
}

.tech-card p {
  color: var(--text-light);
  margin-bottom: 25px;
  line-height: 1.7;
}

.tech-details ul {
  list-style: none;
}

.tech-details li {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 12px;
  font-size: 14px;
  color: var(--text-light);
}

.tech-details i {
  color: #00ffaa;
  font-size: 16px;
}

.tech-card.highlighted .tech-details i {
  color: var(--white);
}

/* 제품 섹션 */
.products {
  background: var(--bg-light);
}

.productSwiper {
  padding: 40px 60px;
  position: relative;
  overflow: hidden;
}

.productSwiper .swiper-wrapper {
  padding-bottom: 20px;
  align-items: stretch;
}

.productSwiper .swiper-slide {
  height: auto;
  display: flex;
}

.swiper-slide .product-card {
  width: 100%;
  height: 100%;
}

.product-card {
  background: var(--white);
  border-radius: 20px;
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  height: 100%;
  display: flex;
  flex-direction: column;
}

.product-card:hover {
  transform: translateY(-10px);
  box-shadow: var(--shadow-lg);
}

.product-image {
  position: relative;
  overflow: hidden;
}

.product-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  aspect-ratio: 4/3;
  transition: var(--transition);
}

.product-card:hover .product-image img {
  transform: scale(1.1);
}

.product-image .image-placeholder {
  aspect-ratio: 4/3;
  background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
  display: flex;
  align-items: center;
  justify-content: center;
}

.product-image i {
  font-size: 60px;
  color: var(--white);
}

.product-info {
  padding: 30px;
  display: flex;
  flex-direction: column;
  flex: 1;
  min-height: 450px;
}

.product-info h3 {
  font-size: 22px;
  margin-bottom: 10px;
  font-weight: 700;
  line-height: 1.3;
  height: 70px;
  display: flex;
  align-items: center;
}

.product-spec {
  color: var(--text-light);
  margin-bottom: 20px;
  font-size: 14px;
  height: 40px;
  display: flex;
  align-items: center;
}

.product-features {
  list-style: none;
  margin-bottom: 25px;
  flex: 1;
  min-height: 200px;
}

.product-features li {
  padding: 8px 0;
  border-bottom: 1px solid #f0f0f0;
  font-size: 14px;
  color: var(--text-light);
}

.product-features li:last-child {
  border-bottom: none;
}

.btn-small {
  padding: 10px 25px;
  font-size: 14px;
  margin-top: auto;
  width: 100%;
  border: 1px solid #0047cc;
  display: flex;
  justify-content: center;
}

/* 스와이퍼 네비게이션 & 페이지네이션 */
.swiper-button-next,
.swiper-button-prev {
  color: var(--primary-color);
  background: var(--white);
  width: 50px;
  height: 50px;
  border-radius: 50%;
  box-shadow: var(--shadow-md);
  transition: var(--transition);
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  z-index: 10;
  margin-top: -50px;
}

.swiper-button-next {
  right: 10px;
}

.swiper-button-prev {
  left: 10px;
}

.swiper-button-next:hover,
.swiper-button-prev:hover {
  background: var(--primary-color);
  color: var(--white);
  transform: translateY(-50%) scale(1.1);
}

.swiper-button-next::after,
.swiper-button-prev::after {
  font-size: 20px;
  font-weight: 900;
}

.swiper-pagination {
  position: relative !important;
  margin-top: 40px !important;
  bottom: 0 !important;
  z-index: 10;
}

.swiper-pagination-bullet {
  width: 12px;
  height: 12px;
  background: #ddd;
  opacity: 1;
  transition: var(--transition);
}

.swiper-pagination-bullet-active {
  background: var(--primary-color);
  width: 30px;
  border-radius: 6px;
}

/* 문의하기 섹션 */
.contact-wrapper {
  /* display: grid;
  grid-template-columns: 1fr 1fr; */
  display: flex;
  justify-content: space-between;
  gap: 60px;

  color: white;
  border-radius: 20px;
  padding: 60px 160px;
  box-shadow: var(--shadow-lg);
}

.contact-info {
  display: flex;
  width: 100%;
  flex-direction: column;
  text-align: start;
}

.contact-info h2 {
  font-size: 45px;
  font-weight: 700;
  margin: 10px 0 20px;
}

.contact-info p {
  color: var(--text-light);
  margin-bottom: 40px;
  font-size: 20px;
}

.contact-details {
  display: flex;
  flex-direction: column;
  gap: 30px;
}

.contact-item {
  display: flex;
  gap: 20px;
  align-items: flex-start;
}

.contact-item i {
  width: 50px;
  height: 50px;
  background: var(--gradient-2);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--white);
  font-size: 20px;
  flex-shrink: 0;
}

.contact-item strong {
  display: block;
  font-size: 16px;
  margin-bottom: 5px;
  color: var(--text-dark);
}

.contact-item p {
  font-size: 14px;
  color: var(--text-light);
  margin: 0;
  line-height: 1.6;
}

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

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 15px;
  border: 2px solid #e0e0e0;
  border-radius: 10px;
  font-size: 15px;
  transition: var(--transition);
  font-family: "Noto Sans KR", sans-serif;
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--primary-color);
}

.form-check {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 25px;
}

.form-check input[type="checkbox"] {
  width: 20px;
  height: 20px;
  cursor: pointer;
}

.form-check label {
  font-size: 14px;
  color: var(--text-light);
  cursor: pointer;
}

.btn-block {
  width: 100%;
  justify-content: center;
}

/* 푸터 */
.footer {
  background: #1a1a2e;
  color: var(--white);
  padding: 60px 0 20px;
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 40px;
  margin-bottom: 40px;
}

.footer-logo {
  font-size: 24px;
  font-weight: 700;
  margin-bottom: 15px;
}

.footer-logo-img {
  margin-top: 20px;
  height: 85px;
  width: auto;
  max-width: 240px;
  filter: brightness(0) invert(1);
  opacity: 0.9;
}

.footer-column h4 {
  font-size: 18px;
  margin-bottom: 20px;
  font-weight: 600;
}

.footer-column p {
  color: rgba(255, 255, 255, 0.7);
  line-height: 1.8;
  font-size: 14px;
}

.footer-column ul {
  list-style: none;
}

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

.footer-column ul li a {
  color: rgba(255, 255, 255, 0.7);
  text-decoration: none;
  font-size: 14px;
  transition: var(--transition);
}

.footer-column ul li a:hover {
  color: var(--white);
  padding-left: 5px;
}

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

.footer-bottom p {
  color: rgba(255, 255, 255, 0.5);
  font-size: 14px;
}

/* 맨 위로 버튼 */
.scroll-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 50px;
  height: 50px;
  background: var(--gradient-2);
  border: none;
  border-radius: 50%;
  color: var(--white);
  font-size: 20px;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transition: var(--transition);
  box-shadow: 0 4px 20px rgba(30, 105, 255, 0.4);
  z-index: 999;
}

.scroll-top.visible {
  opacity: 1;
  visibility: visible;
}

.scroll-top:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 30px rgba(30, 105, 255, 0.6);
}

.product-category {
  color: #091650;
  padding: 15px 30px;
  border-radius: 50px;
  font-weight: 600;
  border: 1px solid #a1a8c7;
  cursor: pointer;
  box-shadow: 0 4px 15px rgba(102, 126, 234, 0.2);
  transition: all 0.25s ease;
}

.product-category i {
  margin-right: 8px;
}

/* Hover 효과 */
.product-category:hover {
  box-shadow: 0 4px 15px rgba(102, 126, 234, 0.45);
  transform: translateY(-3px);
}

/* ★ 활성화(active) 상태 스타일 */
.product-category.active {
  background: linear-gradient(135deg, #1e3a8a 0%, #64748b 100%);
  color: #fff !important;
  border-color: transparent;
  box-shadow: 0 4px 20px rgba(30, 58, 138, 0.4);
}

/* 반응형 - 모바일/태블릿 */
@media (max-width: 768px) {
  .contact-wrapper {
    flex-direction: column; /* 위아래 배치 */
    padding: 32px 20px;
    gap: 24px;
  }

  .contact-info {
    text-align: left; /* 필요하면 center로 바꿔도 됨 */
  }

  .contact-info h2 {
    font-size: 28px;
    margin: 5px 0 15px;
  }

  .contact-info p {
    font-size: 16px;
    margin-bottom: 20px;
  }

  .contact-form {
    width: 100%;
  }

  .battery-cells-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .battery-cell {
    background: white;
    padding: 35px 25px;
    text-align: center;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100px;
  }

  .battery-cell img {
    max-height: 45px;
    max-width: 180px;
    width: auto;
    height: auto;
    object-fit: contain;
  }
  /* 가로 스크롤 방지 */
  html,
  body {
    overflow-x: hidden;
    max-width: 100vw;
    width: 100%;
  }

  * {
    max-width: 100%;
  }

  /* 컨테이너 여백 증가 */
  .container {
    padding: 0 24px;
    width: 100%;
    max-width: 100%;
  }

  section {
    width: 100%;
    max-width: 100vw;
    overflow-x: hidden;
  }

  /* 제품 카테고리 버튼 */
  .product-categories {
    width: 100%;
    max-width: 100%;
    overflow-x: auto;
    flex-wrap: wrap !important;
  }

  .product-categories > div {
    flex-shrink: 0;
  }

  /* 로고 크기 */
  .logo-img {
    height: 45px;
    max-width: 180px;
  }

  .navbar.scrolled .logo-img {
    height: 40px;
  }

  /* 모바일 메뉴 최적화 */
  .nav-menu {
    position: fixed;
    top: 0;
    right: -100%;
    width: 85%;
    max-width: 400px;
    height: 100vh;
    background: rgba(26, 26, 46, 0.98);
    backdrop-filter: blur(10px);
    flex-direction: column;
    justify-content: center;
    align-items: center;
    transition: var(--transition);
    gap: 35px;
    padding: 40px 20px;
    overflow-y: auto;
  }

  .nav-menu.active {
    right: 0;
  }

  /* 터치 영역 확대 (최소 44px) */
  .nav-link {
    color: var(--white) !important;
    font-size: 19px;
    padding: 12px 24px !important;
    min-height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 8px;
  }

  .nav-link:active {
    background: rgba(255, 255, 255, 0.15);
  }

  /* 햄버거 버튼 터치 영역 확대 */
  .hamburger {
    display: flex;
    z-index: 1001;
    width: 48px;
    height: 48px;
    padding: 12px;
  }

  /* 언어 선택 메뉴 터치 개선 */
  .language-menu {
    position: static;
    opacity: 1;
    visibility: visible;
    transform: none;
    background: transparent;
    box-shadow: none;
    margin-top: 10px;
  }

  .language-menu a {
    color: var(--white);
    padding: 12px 24px;
    min-height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 8px;
  }

  .language-menu a:hover,
  .language-menu a:active {
    background: rgba(255, 255, 255, 0.1);
  }

  .language-dropdown {
    display: flex;
    flex-direction: column;
    align-items: center;
    width: 100%;
  }

  .nav-link.language {
    border-color: var(--white);
    min-height: 48px;
  }

  /* 히어로 섹션 모바일 최적화 */
  .hero {
    min-height: 100vh;
    padding-top: 80px;
    width: 100%;
    max-width: 100vw;
    overflow-x: hidden;
  }

  .hero .container {
    width: 100%;
    max-width: 100%;
    padding: 0 20px;
  }

  .hero-content {
    padding: 0;
    width: 100%;
    max-width: 100%;
  }

  .hero-title {
    font-size: 34px;
    line-height: 1.3;
    margin-bottom: 20px;
  }

  .hero-subtitle {
    font-size: 17px;
    line-height: 1.6;
    margin-bottom: 30px;
  }

  .hero-features {
    width: 100%;
    max-width: 100%;
    margin: 30px auto;
    padding: 0;
  }

  .feature-item {
    font-size: 16px;
    padding: 8px 0;
    width: 100%;
  }

  .feature-item i {
    font-size: 18px;
    min-width: 24px;
  }

  /* 버튼 터치 영역 확대 */
  .hero-buttons {
    flex-direction: column;
    gap: 15px;
    width: 100%;
    margin-bottom: 40px;
  }

  .btn {
    width: 100%;
    min-height: 52px;
    font-size: 16px;
    padding: 15px 32px;
  }

  /* 스크롤 인디케이터 위치 조정 */
  .scroll-indicator {
    bottom: 20px;
  }

  /* 섹션 제목 */
  .section-title {
    font-size: 32px;
    line-height: 1.3;
    margin-bottom: 16px;
  }

  .section-subtitle {
    font-size: 16px;
    line-height: 1.6;
  }

  /* 섹션 여백 */
  section {
    padding: 70px 0;
  }

  /* 그리드 레이아웃 1열로 */
  .about-content,
  .contact-wrapper {
    grid-template-columns: 1fr;
    gap: 35px;
  }

  .tech-grid {
    grid-template-columns: 1fr;
    gap: 25px;
  }

  .about-stats {
    grid-template-columns: 1fr;
    gap: 25px;
  }

  .form-row {
    grid-template-columns: 1fr;
  }

  /* 기술 카드 */
  .tech-card {
    padding: 30px 24px;
  }

  .tech-card h3 {
    font-size: 22px;
    margin-bottom: 12px;
  }

  .tech-card p {
    font-size: 15px;
    line-height: 1.7;
  }

  .tech-icon {
    width: 160px;
    height: 160px;
    margin-left: auto;
    margin-right: auto;
  }

  /* 통계 카드 */
  .stat-item {
    padding: 28px 20px;
  }

  .stat-number {
    font-size: 38px;
  }

  .stat-label {
    font-size: 15px;
  }

  /* 제품 슬라이더 */
  .productSwiper {
    padding: 20px 45px;
    width: 100%;
    max-width: 100vw;
    overflow-x: hidden;
  }

  /* 슬라이더 버튼 터치 영역 확대 */
  .swiper-button-next,
  .swiper-button-prev {
    width: 44px;
    height: 44px;
    background: rgba(30, 105, 255, 0.95);
  }

  .swiper-button-next::after,
  .swiper-button-prev::after {
    font-size: 18px;
  }

  /* 제품 카드 최적화 */
  .product-card {
    margin: 0 auto;
    max-width: 480px;
  }

  .product-info {
    min-height: 400px;
    padding: 28px 24px;
  }

  .product-info h3 {
    font-size: 20px;
    height: auto;
    min-height: 60px;
    line-height: 1.4;
  }

  .product-spec {
    font-size: 14px;
  }

  .product-features {
    min-height: 170px;
  }

  .product-features li {
    padding: 10px 0;
    font-size: 14px;
    line-height: 1.5;
  }

  .btn-small {
    min-height: 48px;
    font-size: 15px;
    padding: 12px 28px;
  }

  /* 폼 최적화 - iOS 자동 확대 방지 */
  .form-group input,
  .form-group textarea,
  .form-group select {
    font-size: 16px; /* 중요: 16px 이상이어야 iOS에서 자동 확대 안 됨 */
    min-height: 52px;
    padding: 14px 16px;
  }

  .form-group textarea {
    min-height: 140px;
  }

  .form-group label {
    font-size: 15px;
    margin-bottom: 10px;
  }

  /* 체크박스 터치 영역 확대 */
  .form-check {
    padding: 12px 0;
  }

  .form-check input[type="checkbox"] {
    width: 22px;
    height: 22px;
    min-width: 22px;
    cursor: pointer;
  }

  .form-check label {
    font-size: 14px;
    line-height: 1.6;
    padding-left: 10px;
    cursor: pointer;
  }

  /* Contact 섹션 */
  .contact-wrapper {
    padding: 35px 24px;
  }

  .contact-info h3 {
    font-size: 22px;
  }

  .contact-item {
    padding: 16px 0;
  }

  .contact-item i {
    font-size: 22px;
    min-width: 32px;
  }

  .contact-item strong,
  .contact-item p {
    font-size: 15px;
    line-height: 1.6;
  }

  /* 푸터 */
  .footer-content {
    grid-template-columns: 1fr;
    gap: 35px;
  }

  .footer-column h3,
  .footer-column h4 {
    font-size: 18px;
    margin-bottom: 16px;
  }

  .footer-column p,
  .footer-column li {
    font-size: 14px;
    line-height: 1.7;
  }

  .footer-logo-img {
    height: 45px;
    margin-bottom: 12px;
  }

  /* 맨 위로 버튼 터치 영역 확대 */
  .scroll-top {
    width: 50px;
    height: 50px;
    right: 20px;
    bottom: 20px;
  }

  .scroll-top i {
    font-size: 20px;
  }

  /* 트로잔 파트너십 섹션 모바일 최적화 */
  .trojan-partnership {
    width: 100%;
    max-width: 100vw;
    overflow-x: hidden;
  }

  .trojan-partnership .partnership-content {
    grid-template-columns: 1fr !important;
    gap: 30px !important;
    width: 100%;
    max-width: 100%;
  }

  .partnership-text,
  .partnership-features {
    width: 100%;
    max-width: 100%;
  }

  .partners-container {
    padding: 35px 20px !important;
    width: 100%;
    max-width: 100%;
  }

  .partners-grid {
    grid-template-columns: repeat(2, 1fr) !important;
    gap: 20px !important;
    width: 100%;
    max-width: 100%;
  }

  .partners-grid div {
    padding: 12px !important;
    width: 100%;
    max-width: 100%;
  }

  .partners-grid img {
    height: 35px !important;
    max-width: 100%;
  }
}

@media (max-width: 480px) {
  /* 작은 모바일 최적화 */
  html,
  body {
    overflow-x: hidden;
    max-width: 100vw;
    width: 100%;
  }

  .contact-wrapper {
    padding: 24px 16px;
  }

  .contact-info h2 {
    font-size: 24px;
  }

  .contact-info p {
    font-size: 15px;
  }
  .container {
    padding: 0 20px;
    width: 100%;
    max-width: 100%;
  }

  section {
    width: 100%;
    max-width: 100vw;
    overflow-x: hidden;
  }

  /* 히어로 섹션 */
  .hero-title {
    font-size: 28px;
    line-height: 1.3;
  }

  .hero-subtitle {
    font-size: 15px;
  }

  .feature-item {
    font-size: 14px;
  }

  .feature-item i {
    font-size: 16px;
  }

  /* 버튼 */
  .btn {
    padding: 14px 28px;
    font-size: 15px;
    min-height: 50px;
  }

  .btn-small {
    padding: 12px 24px;
    font-size: 14px;
    min-height: 46px;
  }

  /* 섹션 여백 */
  section {
    padding: 60px 0;
  }

  /* 섹션 제목 */
  .section-title {
    font-size: 28px;
  }

  /* 마우스 스크롤 애니메이션 */
  .mouse-scroll {
    transform: scale(0.8);
  }

  .scroll-text {
    font-size: 10px;
  }

  /* 제품 슬라이더 - 작은 화면에서는 버튼 숨김 */
  .swiper-button-next,
  .swiper-button-prev {
    display: none;
  }

  .productSwiper {
    padding: 20px 10px !important;
  }

  /* 제품 카드 */
  .product-info {
    min-height: 350px;
    padding: 24px 20px;
  }

  .product-info h3 {
    font-size: 18px;
    height: auto;
    min-height: 50px;
  }

  .product-features {
    min-height: 150px;
  }

  .product-features li {
    font-size: 13px;
  }

  /* 기술 카드 */
  .tech-card {
    padding: 24px 20px;
  }

  .tech-card h3 {
    font-size: 20px;
  }

  .tech-card p {
    font-size: 14px;
  }

  .tech-icon {
    width: 140px;
    height: 140px;
    margin-left: auto;
    margin-right: auto;
  }

  /* 통계 */
  .stat-number {
    font-size: 34px;
  }

  .stat-label {
    font-size: 14px;
  }

  /* 폼 */
  .form-group input,
  .form-group textarea,
  .form-group select {
    font-size: 16px; /* 16px 유지 - iOS 자동 확대 방지 */
    min-height: 50px;
  }

  .form-group label {
    font-size: 14px;
  }

  /* Contact */
  .contact-wrapper {
    padding: 28px 20px;
  }

  .contact-item strong,
  .contact-item p {
    font-size: 14px;
  }

  /* 푸터 */
  .footer-column h3,
  .footer-column h4 {
    font-size: 17px;
  }

  .footer-column p,
  .footer-column li {
    font-size: 13px;
  }

  /* 트로잔 파트너십 섹션 */
  .trojan-partnership h2,
  .trojan-partnership h3 {
    font-size: 24px !important;
  }

  .trojan-partnership h4 {
    font-size: 18px !important;
  }

  .trojan-partnership p {
    font-size: 14px !important;
  }

  .partners-container {
    padding: 25px 16px !important;
  }

  /* 핵심 기술 역량 섹션 모바일 최적화 */
  .core-capabilities-section {
    margin-top: 50px !important;
    padding: 30px 15px !important;
  }

  .core-capabilities-section h3 {
    font-size: 24px !important;
    letter-spacing: -0.6px !important;
  }

  .core-capabilities-section h4 {
    font-size: 20px !important;
  }

  .core-capabilities-section p {
    font-size: 14px !important;
  }

  /* Premium Battery Cells 그리드 - 모바일에서 2열 */
  .battery-cells-grid {
    grid-template-columns: repeat(2, 1fr) !important;
    gap: 1px !important;
  }

  .battery-cells-grid > div {
    /* padding: 20px 12px !important; */
    min-height: 70px !important;
  }

  .battery-cells-grid img {
    max-height: 30px !important;
    max-width: 110px !important;
  }

  /* 리튬이온/리튬인산철 배터리 그리드 - 모바일에서 1열 */
  .battery-types-grid {
    grid-template-columns: 1fr !important;
    gap: 1px !important;
  }

  .battery-type-card {
    padding: 30px 20px !important;
  }

  .battery-type-card h5 {
    font-size: 20px !important;
  }

  .battery-type-card img {
    max-height: 140px !important;
  }

  .battery-type-card li {
    font-size: 13px !important;
    margin-bottom: 10px !important;
  }

  /* 배터리 5대 특징 그리드 - 모바일에서 1열 */
  /* 1열로 변경 */
  .battery-features-grid {
    grid-template-columns: 1fr;
    gap: 1px;
  }

  .battery-features-grid > div {
    padding: 30px 20px;
  }

  .battery-features-grid h5 {
    font-size: 18px;
  }

  .battery-features-grid li {
    font-size: 13px;
    line-height: 1.6;
    margin-bottom: 10px;
  }

  .battery-features-grid span[style*="font-size: 14px"] {
    font-size: 12px;
  }

  /* BMS 안의 columns도 모바일에서는 1열로 */
  .battery-features-grid ul[style*="columns: 2"] {
    columns: 1;
    column-gap: 0;
  }

  /* Technical Specifications 헤더 */
  .core-capabilities-section [style*="Technical Specifications"] {
    font-size: 10px !important;
    margin-bottom: 10px !important;
  }

  /* 배터리 특징 섹션 전체 패딩 */
  .core-capabilities-section > div[style*="padding: 70px 50px"] {
    padding: 40px 20px !important;
  }

  /* CTA 섹션 */
  .core-capabilities-section > div[style*="background: #0a0a0a"] {
    padding: 35px 20px !important;
    margin-top: 40px !important;
  }

  .core-capabilities-section > div[style*="background: #0a0a0a"] h4 {
    font-size: 18px !important;
    line-height: 1.4 !important;
  }

  .core-capabilities-section > div[style*="background: #0a0a0a"] h4 span {
    font-size: 16px !important;
  }

  .core-capabilities-section > div[style*="background: #0a0a0a"] p {
    font-size: 13px !important;
  }

  /* 배터리 셀 로고 섹션 여백 */
  .core-capabilities-section > div[style*="margin-bottom: 60px"] {
    margin-bottom: 35px !important;
  }

  /* 헤더 여백 */
  .core-capabilities-section > div[style*="margin-bottom: 70px"] {
    margin-bottom: 40px !important;
  }
}