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

html {
  scroll-behavior: smooth;
  -webkit-tap-highlight-color: transparent;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  background: #f5f7fa;
  color: #1a1a2e;
  line-height: 1.6;
  transition: background 0.3s ease, color 0.3s ease;
}

body.dark {
  background: #0f0f1a;
  color: #e0e0e0;
}

a {
  text-decoration: none;
  color: inherit;
}

ul {
  list-style: none;
}

img,
svg {
  display: block;
  max-width: 100%;
}

/* ===== Container ===== */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* ===== Buttons ===== */
.btn {
  display: inline-block;
  padding: 12px 30px;
  border-radius: 30px;
  border: none;
  cursor: pointer;
  font-size: 16px;
  font-weight: 600;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  text-align: center;
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
}

.btn:active {
  transform: translateY(0);
}

.btn-primary {
  background: linear-gradient(135deg, #667eea, #764ba2);
  color: #fff;
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.2);
  color: #fff;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.3);
}

body.dark .btn-secondary {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.15);
}

/* ===== Section ===== */
.section {
  padding: 80px 0;
}

.section-title {
  text-align: center;
  font-size: 36px;
  font-weight: 700;
  margin-bottom: 15px;
  background: linear-gradient(135deg, #667eea, #764ba2);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.section-desc {
  text-align: center;
  font-size: 18px;
  color: #666;
  margin-bottom: 50px;
  max-width: 700px;
  margin-left: auto;
  margin-right: auto;
}

body.dark .section-desc {
  color: #aaa;
}

/* ===== Glassmorphism ===== */
.glass {
  background: rgba(255, 255, 255, 0.7);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-radius: 20px;
  border: 1px solid rgba(255, 255, 255, 0.3);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
}

body.dark .glass {
  background: rgba(30, 30, 50, 0.7);
  border-color: rgba(255, 255, 255, 0.1);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

/* ===== Cards ===== */
.card {
  background: #fff;
  border-radius: 16px;
  padding: 30px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.06);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  overflow: hidden;
}

body.dark .card {
  background: #1a1a2e;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.12);
}

body.dark .card:hover {
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.5);
}

/* ===== Grid & Flex ===== */
.grid {
  display: grid;
  gap: 30px;
}

.flex {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
}

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

.mt-20 {
  margin-top: 20px;
}

.mb-20 {
  margin-bottom: 20px;
}

/* ===== Header ===== */
header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(0, 0, 0, 0.05);
  transition: background 0.3s ease;
}

body.dark header {
  background: rgba(15, 15, 26, 0.85);
  border-color: rgba(255, 255, 255, 0.05);
}

.header-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 15px 0;
}

.logo {
  font-size: 28px;
  font-weight: 800;
  background: linear-gradient(135deg, #667eea, #764ba2);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  white-space: nowrap;
}

.nav {
  display: flex;
  gap: 25px;
  align-items: center;
}

.nav a {
  font-size: 15px;
  font-weight: 500;
  transition: color 0.3s ease;
  position: relative;
  padding: 4px 0;
}

.nav a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: linear-gradient(135deg, #667eea, #764ba2);
  transition: width 0.3s ease;
  border-radius: 1px;
}

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

.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 5px;
  background: none;
  border: none;
}

.hamburger span {
  display: block;
  width: 28px;
  height: 3px;
  background: #1a1a2e;
  border-radius: 2px;
  transition: transform 0.3s ease, opacity 0.3s ease;
}

body.dark .hamburger span {
  background: #e0e0e0;
}

.mobile-menu {
  display: none;
  position: fixed;
  top: 70px;
  left: 0;
  width: 100%;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  padding: 20px;
  flex-direction: column;
  gap: 15px;
  z-index: 999;
  border-bottom: 1px solid rgba(0, 0, 0, 0.05);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
}

body.dark .mobile-menu {
  background: rgba(15, 15, 26, 0.95);
  border-color: rgba(255, 255, 255, 0.05);
}

.mobile-menu a {
  font-size: 18px;
  font-weight: 500;
  padding: 12px 0;
  border-bottom: 1px solid rgba(0, 0, 0, 0.05);
  transition: color 0.3s ease;
}

body.dark .mobile-menu a {
  border-color: rgba(255, 255, 255, 0.05);
}

.mobile-menu a:hover {
  color: #667eea;
}

.mobile-menu.open {
  display: flex;
}

/* ===== Hero ===== */
#hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  overflow: hidden;
  padding-top: 80px;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, #1a1a2e 0%, #16213e 50%, #0f3460 100%);
  z-index: -2;
}

.hero-bg::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 20% 50%, rgba(102, 126, 234, 0.3) 0%, transparent 50%),
              radial-gradient(circle at 80% 50%, rgba(118, 75, 162, 0.3) 0%, transparent 50%);
  z-index: -1;
  animation: heroGlow 8s ease-in-out infinite alternate;
}

@keyframes heroGlow {
  0% {
    opacity: 0.6;
    transform: scale(1);
  }
  100% {
    opacity: 1;
    transform: scale(1.05);
  }
}

.hero-slider {
  position: absolute;
  inset: 0;
  z-index: -1;
}

.hero-slide {
  position: absolute;
  inset: 0;
  opacity: 0;
  transition: opacity 1s ease;
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero-slide.active {
  opacity: 1;
}

.hero-slide svg {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.hero-content {
  position: relative;
  z-index: 1;
  text-align: center;
  color: #fff;
  max-width: 800px;
  margin: 0 auto;
  padding: 40px 20px;
  animation: heroFadeIn 1.2s ease-out;
}

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

.hero-content h1 {
  font-size: 56px;
  font-weight: 800;
  margin-bottom: 20px;
  line-height: 1.2;
  text-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

.hero-content p {
  font-size: 20px;
  margin-bottom: 30px;
  opacity: 0.9;
  text-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
}

.hero-btns {
  display: flex;
  gap: 20px;
  justify-content: center;
  flex-wrap: wrap;
}

/* ===== Breadcrumb ===== */
.breadcrumb {
  padding: 15px 0;
  font-size: 14px;
  color: #888;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 80px;
}

.breadcrumb a {
  color: #667eea;
  transition: color 0.3s ease;
}

.breadcrumb a:hover {
  color: #764ba2;
}

.breadcrumb span {
  color: #aaa;
}

body.dark .breadcrumb {
  color: #aaa;
}

body.dark .breadcrumb span {
  color: #666;
}

/* ===== About ===== */
#about .grid {
  grid-template-columns: 1fr 1fr;
  align-items: center;
}

.about-text h2 {
  font-size: 32px;
  margin-bottom: 20px;
  background: linear-gradient(135deg, #667eea, #764ba2);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.about-text p {
  margin-bottom: 15px;
  color: #555;
  line-height: 1.8;
}

body.dark .about-text p {
  color: #bbb;
}

.about-image {
  text-align: center;
}

.about-image svg {
  max-width: 100%;
  height: auto;
  border-radius: 16px;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
}

/* ===== Story ===== */
#story {
  background: linear-gradient(135deg, #f0f4ff, #e8e0f0);
}

body.dark #story {
  background: linear-gradient(135deg, #1a1a2e, #16213e);
}

#story .grid {
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.story-card {
  text-align: center;
  padding: 40px 20px;
}

.story-card svg {
  width: 60px;
  height: 60px;
  margin-bottom: 15px;
}

.story-card h3 {
  font-size: 22px;
  margin-bottom: 10px;
}

.story-card p {
  color: #666;
  line-height: 1.7;
}

body.dark .story-card p {
  color: #aaa;
}

/* ===== Culture ===== */
.culture-grid {
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
}

.culture-item {
  text-align: center;
  padding: 30px 20px;
}

.culture-item svg {
  width: 50px;
  height: 50px;
  margin-bottom: 15px;
  transition: transform 0.3s ease;
}

.culture-item:hover svg {
  transform: scale(1.15) rotate(-5deg);
}

.culture-item h3 {
  font-size: 20px;
  margin-bottom: 8px;
}

.culture-item p {
  color: #666;
  font-size: 14px;
}

body.dark .culture-item p {
  color: #aaa;
}

/* ===== Products ===== */
#products {
  background: #f0f4ff;
}

body.dark #products {
  background: #12121e;
}

.product-grid {
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
}

.product-card {
  text-align: center;
  padding: 35px 20px;
  position: relative;
  overflow: hidden;
}

.product-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(135deg, #667eea, #764ba2);
  transform: scaleX(0);
  transition: transform 0.3s ease;
  transform-origin: left;
}

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

.product-card svg {
  width: 60px;
  height: 60px;
  margin-bottom: 15px;
  transition: transform 0.3s ease;
}

.product-card:hover svg {
  transform: scale(1.1) rotate(-3deg);
}

.product-card h3 {
  font-size: 22px;
  margin-bottom: 10px;
}

.product-card p {
  color: #666;
  font-size: 14px;
  line-height: 1.6;
}

body.dark .product-card p {
  color: #aaa;
}

/* ===== Advantages ===== */
.advantages-grid {
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}

.advantage-item {
  text-align: center;
  padding: 25px 15px;
}

.advantage-item svg {
  width: 45px;
  height: 45px;
  margin-bottom: 12px;
  transition: transform 0.3s ease;
}

.advantage-item:hover svg {
  transform: scale(1.2) rotate(5deg);
}

.advantage-item h3 {
  font-size: 18px;
  margin-bottom: 8px;
}

.advantage-item p {
  color: #666;
  font-size: 13px;
}

body.dark .advantage-item p {
  color: #aaa;
}

/* ===== Services ===== */
.service-grid {
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.service-card {
  padding: 30px 20px;
  text-align: center;
}

.service-card svg {
  width: 50px;
  height: 50px;
  margin-bottom: 15px;
  transition: transform 0.3s ease;
}

.service-card:hover svg {
  transform: translateY(-5px) scale(1.05);
}

.service-card h3 {
  font-size: 20px;
  margin-bottom: 10px;
}

.service-card p {
  color: #666;
  font-size: 14px;
  line-height: 1.6;
}

body.dark .service-card p {
  color: #aaa;
}

/* ===== Solutions ===== */
.solution-grid {
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
}

.solution-card {
  padding: 30px 20px;
  text-align: center;
  border-left: 4px solid transparent;
  transition: border-color 0.3s ease, transform 0.3s ease;
}

.solution-card:hover {
  border-left-color: #667eea;
  transform: translateX(5px);
}

.solution-card svg {
  width: 50px;
  height: 50px;
  margin-bottom: 15px;
}

.solution-card h3 {
  font-size: 20px;
  margin-bottom: 10px;
}

.solution-card p {
  color: #666;
  font-size: 14px;
  line-height: 1.6;
}

body.dark .solution-card p {
  color: #aaa;
}

/* ===== Scenarios ===== */
.scenario-grid {
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.scenario-card {
  position: relative;
  padding: 30px 20px;
  text-align: center;
  overflow: hidden;
}

.scenario-card::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(135deg, #667eea, #764ba2);
  transform: scaleX(0);
  transition: transform 0.3s ease;
  transform-origin: right;
}

.scenario-card:hover::after {
  transform: scaleX(1);
  transform-origin: left;
}

.scenario-card svg {
  width: 50px;
  height: 50px;
  margin-bottom: 15px;
}

.scenario-card h3 {
  font-size: 20px;
  margin-bottom: 10px;
}

.scenario-card p {
  color: #666;
  font-size: 14px;
  line-height: 1.6;
}

body.dark .scenario-card p {
  color: #aaa;
}

/* ===== Data Section ===== */
.data-section {
  background: linear-gradient(135deg, #1a1a2e, #16213e);
  color: #fff;
}

.data-section .section-title {
  color: #fff;
  -webkit-text-fill-color: #fff;
}

.data-section .section-desc {
  color: rgba(255, 255, 255, 0.7);
}

.data-grid {
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.data-item {
  text-align: center;
  padding: 30px 10px;
}

.data-item .number {
  font-size: 48px;
  font-weight: 800;
  background: linear-gradient(135deg, #667eea, #764ba2);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1.2;
}

.data-item .label {
  font-size: 16px;
  margin-top: 10px;
  opacity: 0.8;
}

/* ===== Cases ===== */
.case-grid {
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

.case-card {
  padding: 25px;
  text-align: center;
}

.case-card svg {
  width: 100%;
  height: 180px;
  border-radius: 12px;
  margin-bottom: 15px;
  object-fit: cover;
  transition: transform 0.3s ease;
}

.case-card:hover svg {
  transform: scale(1.03);
}

.case-card h3 {
  font-size: 20px;
  margin-bottom: 8px;
}

.case-card p {
  color: #666;
  font-size: 14px;
  line-height: 1.6;
}

body.dark .case-card p {
  color: #aaa;
}

/* ===== Clients ===== */
.client-grid {
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  align-items: center;
  gap: 20px;
}

.client-item {
  text-align: center;
  padding: 20px;
  opacity: 0.6;
  transition: opacity 0.3s ease, transform 0.3s ease;
}

.client-item:hover {
  opacity: 1;
  transform: scale(1.05);
}

.client-item svg {
  width: 80px;
  height: 40px;
  margin: 0 auto;
}

/* ===== Testimonials ===== */
.testimonial-grid {
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

.testimonial-card {
  padding: 30px 20px;
  position: relative;
}

.testimonial-card::before {
  content: '"';
  font-size: 60px;
  position: absolute;
  top: 10px;
  left: 20px;
  color: #667eea;
  opacity: 0.2;
  font-family: serif;
  line-height: 1;
}

.testimonial-card p {
  font-style: italic;
  margin-bottom: 15px;
  color: #555;
  line-height: 1.7;
}

body.dark .testimonial-card p {
  color: #bbb;
}

.testimonial-card .author {
  font-weight: 600;
  color: #667eea;
}

.testimonial-card .role {
  font-size: 13px;
  color: #888;
  margin-top: 2px;
}

/* ===== News ===== */
.news-grid {
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

.news-card {
  padding: 25px;
}

.news-card .date {
  font-size: 13px;
  color: #888;
  margin-bottom: 8px;
}

.news-card h3 {
  font-size: 20px;
  margin-bottom: 10px;
  transition: color 0.3s ease;
}

.news-card:hover h3 {
  color: #667eea;
}

.news-card p {
  color: #666;
  font-size: 14px;
  line-height: 1.6;
}

body.dark .news-card p {
  color: #aaa;
}

.news-card .tag {
  display: inline-block;
  padding: 4px 12px;
  border-radius: 20px;
  font-size: 12px;
  background: #667eea;
  color: #fff;
  margin-bottom: 10px;
  font-weight: 500;
}

/* ===== Articles ===== */
.article-grid {
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.article-card {
  padding: 25px;
}

.article-card .tag {
  display: inline-block;
  padding: 4px 12px;
  border-radius: 20px;
  font-size: 12px;
  background: #764ba2;
  color: #fff;
  margin-bottom: 10px;
  font-weight: 500;
}

.article-card h3 {
  font-size: 18px;
  margin-bottom: 8px;
  transition: color 0.3s ease;
}

.article-card:hover h3 {
  color: #764ba2;
}

.article-card p {
  color: #666;
  font-size: 14px;
  line-height: 1.6;
}

body.dark .article-card p {
  color: #aaa;
}

.article-card .date {
  font-size: 13px;
  color: #888;
  margin-top: 10px;
}

/* ===== Hot ===== */
.hot-grid {
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
}

.hot-card {
  padding: 20px;
  display: flex;
  align-items: center;
  gap: 15px;
}

.hot-card .rank {
  font-size: 24px;
  font-weight: 800;
  color: #667eea;
  min-width: 30px;
  text-align: center;
}

.hot-card h3 {
  font-size: 16px;
  margin-bottom: 4px;
}

.hot-card p {
  font-size: 13px;
  color: #888;
}

/* ===== FAQ ===== */
.faq-list {
  max-width: 800px;
  margin: 0 auto;
}

.faq-item {
  border-bottom: 1px solid #eee;
  padding: 18px 0;
  cursor: pointer;
  transition: background 0.3s ease;
}

body.dark .faq-item {
  border-color: #333;
}

.faq-item:hover {
  background: rgba(102, 126, 234, 0.03);
}

body.dark .faq-item:hover {
  background: rgba(255, 255, 255, 0.02);
}

.faq-question {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 18px;
  font-weight: 500;
  user-select: none;
}

.faq-question .icon {
  font-size: 22px;
  transition: transform 0.3s ease;
  flex-shrink: 0;
  margin-left: 10px;
}

.faq-item.open .faq-question .icon {
  transform: rotate(45deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.4s ease;
  color: #666;
  padding-top: 0;
  line-height: 1.7;
}

body.dark .faq-answer {
  color: #aaa;
}

.faq-item.open .faq-answer {
  max-height: 300px;
  padding-top: 15px;
}

/* ===== HowTo ===== */
.howto-grid {
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  counter-reset: step;
}

.howto-step {
  text-align: center;
  padding: 30px 20px;
  position: relative;
}

.howto-step::before {
  counter-increment: step;
  content: counter(step);
  position: absolute;
  top: -10px;
  left: 50%;
  transform: translateX(-50%);
  width: 40px;
  height: 40px;
  background: linear-gradient(135deg, #667eea, #764ba2);
  color: #fff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  font-weight: 700;
  box-shadow: 0 4px 12px rgba(102, 126, 234, 0.3);
}

.howto-step svg {
  width: 50px;
  height: 50px;
  margin-bottom: 15px;
  margin-top: 20px;
}

.howto-step h3 {
  font-size: 18px;
  margin-bottom: 8px;
}

.howto-step p {
  color: #666;
  font-size: 14px;
  line-height: 1.6;
}

body.dark .howto-step p {
  color: #aaa;
}

/* ===== Contact ===== */
.contact-grid {
  grid-template-columns: 1fr 1fr;
  gap: 40px;
}

.contact-info {
  padding: 30px;
}

.contact-info h3 {
  font-size: 24px;
  margin-bottom: 20px;
  background: linear-gradient(135deg, #667eea, #764ba2);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.contact-info p {
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  gap: 10px;
  line-height: 1.6;
}

.contact-info svg {
  width: 24px;
  height: 24px;
  flex-shrink: 0;
}

.contact-form {
  display: flex;
  flex-direction: column;
  gap: 15px;
  padding: 30px;
}

.contact-form input,
.contact-form textarea {
  padding: 14px 18px;
  border: 1px solid #ddd;
  border-radius: 12px;
  font-size: 16px;
  background: rgba(255, 255, 255, 0.8);
  transition: border-color 0.3s ease, box-shadow 0.3s ease;
  font-family: inherit;
}

body.dark .contact-form input,
body.dark .contact-form textarea {
  background: rgba(30, 30, 50, 0.8);
  border-color: #444;
  color: #e0e0e0;
}

.contact-form input:focus,
.contact-form textarea:focus {
  outline: none;
  border-color: #667eea;
  box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

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

.contact-form .btn {
  align-self: flex-start;
}

/* ===== Sitemap ===== */
.sitemap-grid {
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
}

.sitemap-group h3 {
  font-size: 18px;
  margin-bottom: 15px;
  color: #667eea;
}

.sitemap-group a {
  display: block;
  padding: 5px 0;
  font-size: 14px;
  color: #666;
  transition: color 0.3s ease, padding-left 0.3s ease;
}

body.dark .sitemap-group a {
  color: #aaa;
}

.sitemap-group a:hover {
  color: #667eea;
  padding-left: 5px;
}

/* ===== Friends ===== */
.friend-grid {
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 15px;
  align-items: center;
}

.friend-item {
  text-align: center;
  padding: 15px;
  font-size: 14px;
  color: #888;
  transition: color 0.3s ease, background 0.3s ease;
  border-radius: 8px;
}

.friend-item:hover {
  color: #667eea;
  background: rgba(102, 126, 234, 0.05);
}

body.dark .friend-item:hover {
  background: rgba(255, 255, 255, 0.03);
}

/* ===== Footer ===== */
footer {
  background: #1a1a2e;
  color: #ccc;
  padding: 60px 0 30px;
}

.footer-grid {
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 40px;
  margin-bottom: 40px;
}

.footer-col h3 {
  font-size: 18px;
  margin-bottom: 20px;
  color: #fff;
}

.footer-col p,
.footer-col a {
  font-size: 14px;
  color: #aaa;
  line-height: 2;
  transition: color 0.3s ease;
}

.footer-col a:hover {
  color: #667eea;
}

.footer-bottom {
  text-align: center;
  padding-top: 30px;
  border-top: 1px solid #333;
  font-size: 13px;
  color: #888;
  line-height: 1.8;
}

.footer-bottom a {
  color: #667eea;
  transition: color 0.3s ease;
}

.footer-bottom a:hover {
  color: #764ba2;
}

/* ===== Back to Top ===== */
.back-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 50px;
  height: 50px;
  background: linear-gradient(135deg, #667eea, #764ba2);
  color: #fff;
  border: none;
  border-radius: 50%;
  cursor: pointer;
  font-size: 24px;
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 999;
  box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
  transition: transform 0.3s ease, opacity 0.3s ease;
  opacity: 0;
}

.back-top.show {
  display: flex;
  opacity: 1;
}

.back-top:hover {
  transform: scale(1.1) translateY(-2px);
  box-shadow: 0 6px 20px rgba(102, 126, 234, 0.5);
}

.back-top:active {
  transform: scale(0.95);
}

/* ===== Dark Mode Toggle ===== */
.dark-toggle {
  position: fixed;
  bottom: 90px;
  right: 30px;
  width: 50px;
  height: 50px;
  background: #1a1a2e;
  color: #ffd700;
  border: 2px solid rgba(255, 255, 255, 0.1);
  border-radius: 50%;
  cursor: pointer;
  font-size: 22px;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 999;
  transition: transform 0.3s ease, background 0.3s ease, color 0.3s ease;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

body.dark .dark-toggle {
  background: #e0e0e0;
  color: #1a1a2e;
}

.dark-toggle:hover {
  transform: scale(1.1) rotate(-15deg);
}

/* ===== Scroll Animations ===== */
.card,
.glass,
.story-card,
.culture-item,
.product-card,
.advantage-item,
.service-card,
.solution-card,
.scenario-card,
.case-card,
.testimonial-card,
.news-card,
.article-card,
.hot-card,
.howto-step {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.card.visible,
.glass.visible,
.story-card.visible,
.culture-item.visible,
.product-card.visible,
.advantage-item.visible,
.service-card.visible,
.solution-card.visible,
.scenario-card.visible,
.case-card.visible,
.testimonial-card.visible,
.news-card.visible,
.article-card.visible,
.hot-card.visible,
.howto-step.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Staggered delay for grid items */
.grid > *:nth-child(1) { transition-delay: 0.05s; }
.grid > *:nth-child(2) { transition-delay: 0.1s; }
.grid > *:nth-child(3) { transition-delay: 0.15s; }
.grid > *:nth-child(4) { transition-delay: 0.2s; }
.grid > *:nth-child(5) { transition-delay: 0.25s; }
.grid > *:nth-child(6) { transition-delay: 0.3s; }
.grid > *:nth-child(7) { transition-delay: 0.35s; }
.grid > *:nth-child(8) { transition-delay: 0.4s; }

/* ===== Responsive ===== */
@media (max-width: 1024px) {
  .hero-content h1 {
    font-size: 44px;
  }
  
  .section-title {
    font-size: 32px;
  }
  
  .data-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .contact-grid {
    gap: 30px;
  }
}

@media (max-width: 768px) {
  .nav {
    display: none;
  }
  
  .hamburger {
    display: flex;
  }
  
  .hero-content h1 {
    font-size: 36px;
  }
  
  .hero-content p {
    font-size: 16px;
  }
  
  .section-title {
    font-size: 28px;
  }
  
  .section-desc {
    font-size: 16px;
    margin-bottom: 40px;
  }
  
  .section {
    padding: 60px 0;
  }
  
  .data-grid {
    grid-template-columns: 1fr 1fr;
    gap: 15px;
  }
  
  .contact-grid {
    grid-template-columns: 1fr;
    gap: 30px;
  }
  
  #about .grid {
    grid-template-columns: 1fr;
    gap: 30px;
  }
  
  .about-text h2 {
    font-size: 28px;
  }
  
  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 30px;
  }
  
  .back-top {
    bottom: 20px;
    right: 20px;
    width: 40px;
    height: 40px;
    font-size: 18px;
  }
  
  .dark-toggle {
    bottom: 70px;
    right: 20px;
    width: 40px;
    height: 40px;
    font-size: 18px;
  }
  
  .data-item .number {
    font-size: 36px;
  }
  
  .hero-btns {
    flex-direction: column;
    align-items: center;
  }
  
  .hero-btns .btn {
    width: 100%;
    max-width: 280px;
  }
  
  .faq-question {
    font-size: 16px;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 15px;
  }
  
  .hero-content h1 {
    font-size: 28px;
  }
  
  .hero-content p {
    font-size: 15px;
  }
  
  .section-title {
    font-size: 24px;
  }
  
  .section-desc {
    font-size: 14px;
    margin-bottom: 30px;
  }
  
  .section {
    padding: 40px 0;
  }
  
  .data-grid {
    grid-template-columns: 1fr;
    gap: 15px;
  }
  
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 25px;
  }
  
  .logo {
    font-size: 22px;
  }
  
  .data-item .number {
    font-size: 32px;
  }
  
  .data-item .label {
    font-size: 14px;
  }
  
  .product-card,
  .service-card,
  .solution-card,
  .scenario-card {
    padding: 25px 15px;
  }
  
  .contact-info,
  .contact-form {
    padding: 20px;
  }
  
  .contact-form input,
  .contact-form textarea {
    font-size: 14px;
    padding: 12px 14px;
  }
  
  .faq-question {
    font-size: 15px;
  }
  
  .howto-step {
    padding: 25px 15px;
  }
  
  .sitemap-grid {
    grid-template-columns: 1fr 1fr;
    gap: 20px;
  }
  
  .friend-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* ===== Reduced Motion ===== */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
  
  .card,
  .glass,
  .story-card,
  .culture-item,
  .product-card,
  .advantage-item,
  .service-card,
  .solution-card,
  .scenario-card,
  .case-card,
  .testimonial-card,
  .news-card,
  .article-card,
  .hot-card,
  .howto-step {
    opacity: 1 !important;
    transform: none !important;
  }
}

/* ===== Selection ===== */
::selection {
  background: rgba(102, 126, 234, 0.3);
  color: #1a1a2e;
}

body.dark ::selection {
  background: rgba(102, 126, 234, 0.4);
  color: #fff;
}

/* ===== Focus ===== */
:focus-visible {
  outline: 2px solid #667eea;
  outline-offset: 2px;
  border-radius: 4px;
}

/* ===== Scrollbar ===== */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: #667eea;
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: #764ba2;
}

body.dark ::-webkit-scrollbar-thumb {
  background: #764ba2;
}

body.dark ::-webkit-scrollbar-thumb:hover {
  background: #667eea;
}