/* ===== CSS Variables (Design Tokens) ===== */
:root {
  /* Colors */
  --primary-50: #eff6ff;
  --primary-100: #dbeafe;
  --primary-200: #bfdbfe;
  --primary-300: #93c5fd;
  --primary-400: #60a5fa;
  --primary-500: #3b82f6;
  --primary-600: #2563eb;
  --primary-700: #1d4ed8;
  --primary-800: #1e40af;
  
  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-300: #d1d5db;
  --gray-400: #9ca3af;
  --gray-500: #6b7280;
  --gray-600: #4b5563;
  --gray-700: #374151;
  --gray-800: #1f2937;
  --gray-900: #111827;
  
  --success-50: #ecfdf5;
  --success-600: #059669;
  
  --white: #ffffff;
  
  /* Typography */
  --font-family: 'Inter', 'PingFang SC', 'Microsoft YaHei', -apple-system, BlinkMacSystemFont, sans-serif;
  
  /* Spacing */
  --container-max: 1280px;
  --section-padding: 5rem;
  --section-padding-mobile: 3rem;
  
  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.5rem;
  --radius-full: 9999px;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
  
  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 200ms ease;
  --transition-slow: 300ms ease;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family);
  font-size: 16px;
  line-height: 1.6;
  color: var(--gray-700);
  background-color: var(--white);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

img {
  max-width: 100%;
  height: auto;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

input, textarea {
  font-family: inherit;
  font-size: inherit;
}

ul {
  list-style: none;
}

/* ===== Utilities ===== */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 1rem;
}

@media (min-width: 1024px) {
  .container {
    padding: 0 2rem;
  }
}

.hidden {
  display: none !important;
}

.icon {
  width: 1.25rem;
  height: 1.25rem;
  flex-shrink: 0;
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  transition: all var(--transition-base);
}

.btn-primary {
  background: var(--primary-600);
  color: var(--white);
}

.btn-primary:hover {
  background: var(--primary-700);
}

.btn-lg {
  padding: 1rem 2rem;
  font-size: 1.125rem;
}

.btn-block {
  width: 100%;
}

/* ===== Header ===== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 50;
  background: var(--white);
  box-shadow: var(--shadow-sm);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 4rem;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.logo-icon {
  width: 2rem;
  height: 2rem;
  background: linear-gradient(135deg, var(--primary-600), var(--primary-500));
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--white);
  font-weight: 700;
  font-size: 1.125rem;
}

.logo-text {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--gray-800);
}

.nav-desktop {
  display: none;
  align-items: center;
  gap: 2rem;
}

.nav-desktop a {
  color: var(--gray-600);
  font-weight: 500;
  transition: color var(--transition-base);
}

.nav-desktop a:hover {
  color: var(--primary-600);
}

.header-right {
  display: none;
  align-items: center;
  gap: 1rem;
}

.lang-switch {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  color: var(--gray-600);
  font-size: 0.875rem;
  font-weight: 500;
  transition: color var(--transition-base);
}

.lang-switch:hover {
  color: var(--primary-600);
}

.header-cta {
  padding: 0.5rem 1.25rem;
}

.mobile-menu-btn {
  display: flex;
  padding: 0.5rem;
  color: var(--gray-600);
}

.mobile-menu-btn .icon {
  width: 1.5rem;
  height: 1.5rem;
}

.mobile-menu {
  padding: 1rem;
  border-top: 1px solid var(--gray-100);
  animation: fadeIn 0.2s ease;
}

.mobile-nav {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.mobile-nav a {
  color: var(--gray-600);
  font-weight: 500;
  padding: 0.5rem 0;
}

.mobile-menu-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 1rem;
  padding-top: 1rem;
  border-top: 1px solid var(--gray-100);
}

.lang-switch-mobile {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  color: var(--gray-600);
  font-size: 0.875rem;
}

@media (min-width: 768px) {
  .nav-desktop {
    display: flex;
  }
  
  .header-right {
    display: flex;
  }
  
  .mobile-menu-btn {
    display: none;
  }
  
  .mobile-menu {
    display: none !important;
  }
}

/* ===== Hero Section ===== */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: 4rem;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, var(--primary-50), var(--white), var(--primary-100));
}

.hero-decor-1 {
  position: absolute;
  top: 5rem;
  right: 2.5rem;
  width: 18rem;
  height: 18rem;
  background: var(--primary-200);
  border-radius: 50%;
  filter: blur(60px);
  opacity: 0.3;
  animation: pulse 4s ease-in-out infinite;
}

.hero-decor-2 {
  position: absolute;
  bottom: 5rem;
  left: 2.5rem;
  width: 24rem;
  height: 24rem;
  background: var(--primary-300);
  border-radius: 50%;
  filter: blur(60px);
  opacity: 0.2;
}

.hero-content {
  position: relative;
  z-index: 10;
  text-align: center;
  max-width: 56rem;
  margin: 0 auto;
}

.tagline {
  display: inline-block;
  padding: 0.5rem 1rem;
  background: var(--primary-100);
  color: var(--primary-600);
  border-radius: var(--radius-full);
  font-size: 0.875rem;
  font-weight: 500;
  margin-bottom: 1.5rem;
  animation: fadeIn 0.6s ease;
}

.hero-title {
  font-size: 2.25rem;
  font-weight: 700;
  color: var(--gray-900);
  margin-bottom: 1.5rem;
  line-height: 1.2;
  animation: slideUp 0.6s ease 0.1s both;
}

.hero-subtitle {
  font-size: 1.125rem;
  color: var(--gray-600);
  margin-bottom: 2.5rem;
  max-width: 42rem;
  margin-left: auto;
  margin-right: auto;
  animation: slideUp 0.6s ease 0.2s both;
}

.hero-cta {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  animation: slideUp 0.6s ease 0.3s both;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2rem;
  margin-top: 5rem;
}

.stat-item {
  text-align: center;
  animation: fadeIn 0.6s ease 0.4s both;
}

.stat-value {
  font-size: 1.875rem;
  font-weight: 700;
  color: var(--primary-600);
  margin-bottom: 0.5rem;
}

.stat-label {
  color: var(--gray-600);
}

@media (min-width: 768px) {
  .hero-title {
    font-size: 3rem;
  }
  
  .hero-subtitle {
    font-size: 1.25rem;
  }
  
  .hero-cta {
    flex-direction: row;
  }
  
  .stats-grid {
    grid-template-columns: repeat(4, 1fr);
  }
  
  .stat-value {
    font-size: 2.25rem;
  }
}

@media (min-width: 1024px) {
  .hero-title {
    font-size: 3.75rem;
  }
}

/* ===== Sections ===== */
.section {
  padding: var(--section-padding-mobile) 0;
}

.section-white {
  background: var(--white);
}

.section-gray {
  background: var(--gray-50);
}

.section-primary {
  background: linear-gradient(135deg, var(--primary-600), var(--primary-800));
  color: var(--white);
}

.section-header {
  text-align: center;
  margin-bottom: 3rem;
}

.section-header-light .section-title {
  color: var(--white);
}

.section-title {
  font-size: 1.875rem;
  font-weight: 700;
  color: var(--gray-900);
  margin-bottom: 1rem;
}

.section-subtitle {
  font-size: 1.125rem;
  color: var(--gray-600);
  max-width: 42rem;
  margin: 0 auto;
}

@media (min-width: 768px) {
  .section {
    padding: var(--section-padding) 0;
  }
  
  .section-title {
    font-size: 2.25rem;
  }
  
  .section-header {
    margin-bottom: 4rem;
  }
}

/* ===== Core Business Section ===== */
.business-grid {
  display: grid;
  gap: 2rem;
}

.business-card {
  background: var(--white);
  border: 1px solid var(--gray-100);
  border-radius: var(--radius-xl);
  padding: 1.5rem;
  transition: all var(--transition-slow);
}

.business-card:hover {
  box-shadow: var(--shadow-xl);
  transform: translateY(-4px);
}

.business-icon {
  width: 3.5rem;
  height: 3.5rem;
  background: var(--primary-100);
  border-radius: var(--radius-xl);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.25rem;
  transition: all var(--transition-base);
}

.business-icon svg {
  width: 1.75rem;
  height: 1.75rem;
  color: var(--primary-600);
  transition: color var(--transition-base);
}

.business-card:hover .business-icon {
  background: var(--primary-600);
}

.business-card:hover .business-icon svg {
  color: var(--white);
}

.business-card h3 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--gray-900);
  margin-bottom: 0.75rem;
}

.business-card p {
  color: var(--gray-600);
  line-height: 1.7;
}

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

@media (min-width: 1024px) {
  .business-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}

/* ===== Advantages Section ===== */
.advantages-grid {
  display: grid;
  gap: 1.5rem;
}

.advantage-card {
  display: flex;
  gap: 1.25rem;
  padding: 1.5rem;
  background: var(--white);
  border-radius: var(--radius-xl);
  transition: box-shadow var(--transition-slow);
}

.advantage-card:hover {
  box-shadow: var(--shadow-lg);
}

.advantage-icon {
  flex-shrink: 0;
  width: 3rem;
  height: 3rem;
  background: linear-gradient(135deg, var(--primary-500), var(--primary-600));
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
}

.advantage-icon svg {
  width: 1.5rem;
  height: 1.5rem;
  color: var(--white);
}

.advantage-content h3 {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--gray-900);
  margin-bottom: 0.5rem;
}

.advantage-content p {
  font-size: 0.875rem;
  color: var(--gray-600);
  line-height: 1.7;
}

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

@media (min-width: 1024px) {
  .advantages-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* ===== Solutions Section ===== */
.solutions-grid {
  display: grid;
  gap: 2rem;
}

.solution-card {
  position: relative;
  background: linear-gradient(135deg, var(--gray-50), var(--white));
  border: 1px solid var(--gray-100);
  border-radius: var(--radius-2xl);
  padding: 2rem;
  transition: box-shadow var(--transition-slow);
  overflow: hidden;
}

.solution-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background: linear-gradient(180deg, var(--primary-500), var(--primary-600));
  border-radius: var(--radius-2xl) 0 0 var(--radius-2xl);
  opacity: 0;
  transition: opacity var(--transition-base);
}

.solution-card:hover {
  box-shadow: var(--shadow-xl);
}

.solution-card:hover::before {
  opacity: 1;
}

.solution-card h3 {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--gray-900);
  margin-bottom: 0.75rem;
}

.solution-card > p {
  color: var(--gray-600);
  margin-bottom: 1.5rem;
}

.solution-features {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.solution-features li {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.check-icon {
  width: 1.25rem;
  height: 1.25rem;
  color: var(--primary-500);
  flex-shrink: 0;
}

.solution-features span {
  color: var(--gray-700);
}

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

/* ===== About Section ===== */
.about-company {
  font-size: 1.25rem;
  color: var(--primary-100);
  margin-bottom: 1.5rem;
}

.about-desc {
  color: var(--primary-100);
  max-width: 48rem;
  margin: 0 auto;
  line-height: 1.8;
}

.values-grid {
  display: grid;
  gap: 2rem;
  margin-bottom: 4rem;
}

.value-card {
  background: rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(8px);
  border-radius: var(--radius-xl);
  padding: 1.5rem;
  text-align: center;
}

.value-icon {
  width: 3.5rem;
  height: 3.5rem;
  background: rgba(255, 255, 255, 0.2);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 1rem;
}

.value-icon svg {
  width: 1.75rem;
  height: 1.75rem;
  color: var(--white);
}

.value-card h3 {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
}

.value-card p {
  font-size: 0.875rem;
  color: var(--primary-100);
}

@media (min-width: 768px) {
  .values-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* Timeline */
.timeline-section {
  max-width: 48rem;
  margin: 0 auto;
}

.timeline-title {
  font-size: 1.5rem;
  font-weight: 700;
  text-align: center;
  margin-bottom: 2rem;
}

.timeline {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.timeline-line {
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  width: 2px;
  height: 100%;
  background: rgba(255, 255, 255, 0.3);
}

.timeline-item {
  position: relative;
  display: flex;
  align-items: center;
}

.timeline-left {
  justify-content: flex-start;
}

.timeline-right {
  justify-content: flex-end;
}

.timeline-content {
  width: 42%;
  background: rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(8px);
  border-radius: var(--radius-lg);
  padding: 1rem;
}

.timeline-left .timeline-content {
  text-align: right;
  margin-right: 2rem;
}

.timeline-right .timeline-content {
  text-align: left;
  margin-left: 2rem;
}

.timeline-year {
  color: var(--primary-200);
  font-weight: 600;
  margin-bottom: 0.25rem;
}

.timeline-event {
  font-size: 0.875rem;
}

.timeline-dot {
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  width: 1rem;
  height: 1rem;
  background: var(--white);
  border: 4px solid var(--primary-400);
  border-radius: 50%;
}

/* ===== Contact Section ===== */
.contact-grid {
  display: grid;
  gap: 2rem;
  max-width: 64rem;
  margin: 0 auto;
}

.contact-info {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.contact-item {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
}

.contact-icon {
  width: 3rem;
  height: 3rem;
  background: var(--primary-100);
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.contact-icon svg {
  width: 1.5rem;
  height: 1.5rem;
  color: var(--primary-600);
}

.contact-item h3 {
  font-weight: 600;
  color: var(--gray-900);
  margin-bottom: 0.25rem;
}

.contact-item a {
  color: var(--primary-600);
  word-break: break-all;
}

.contact-item a:hover {
  text-decoration: underline;
}

.contact-item p {
  color: var(--gray-600);
}

.contact-highlight {
  background: linear-gradient(135deg, var(--primary-600), var(--primary-700));
  border-radius: var(--radius-xl);
  padding: 1.25rem 1.5rem;
  color: var(--white);
}

.contact-highlight h3 {
  font-weight: 600;
  font-size: 1.125rem;
  margin-bottom: 0.5rem;
}

.contact-highlight p {
  font-size: 0.875rem;
  color: var(--primary-100);
}

.contact-form-wrapper {
  background: var(--white);
  border-radius: var(--radius-xl);
  padding: 1.5rem;
  box-shadow: var(--shadow-lg);
}

.form-row {
  display: grid;
  gap: 1rem;
}

.form-group {
  margin-bottom: 1rem;
}

.form-group label {
  display: block;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--gray-700);
  margin-bottom: 0.5rem;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-lg);
  outline: none;
  transition: all var(--transition-base);
}

.form-group input:focus,
.form-group textarea:focus {
  border-color: var(--primary-500);
  box-shadow: 0 0 0 3px var(--primary-100);
}

.form-group textarea {
  resize: none;
}

.form-success {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  margin-top: 1rem;
  padding: 1rem;
  background: var(--success-50);
  color: var(--success-600);
  border-radius: var(--radius-lg);
}

.form-hint {
  margin-top: 1rem;
  text-align: center;
  font-size: 0.875rem;
  color: var(--gray-500);
}

.form-hint a {
  color: var(--primary-600);
}

.form-hint a:hover {
  text-decoration: underline;
}

@media (min-width: 768px) {
  .form-row {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .contact-form-wrapper {
    padding: 2rem;
  }
}

@media (min-width: 1024px) {
  .contact-grid {
    grid-template-columns: 2fr 3fr;
    gap: 3rem;
  }
}

/* ===== Footer ===== */
.footer {
  background: var(--gray-900);
  color: var(--gray-300);
  padding: 3rem 0;
}

.footer-grid {
  display: grid;
  gap: 2rem;
  margin-bottom: 2rem;
}

.footer-brand .logo {
  margin-bottom: 1rem;
}

.footer-brand .logo-text {
  color: var(--white);
}

.footer-brand p {
  font-size: 0.875rem;
  color: var(--gray-400);
  line-height: 1.7;
}

.footer-links h4,
.footer-contact h4 {
  color: var(--white);
  font-weight: 600;
  margin-bottom: 1rem;
}

.footer-links ul {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.footer-links li {
  font-size: 0.875rem;
  color: var(--gray-400);
  cursor: pointer;
  transition: color var(--transition-base);
}

.footer-links li:hover {
  color: var(--white);
}

.footer-contact p {
  font-size: 0.875rem;
  color: var(--gray-400);
}

.footer-bottom {
  padding-top: 2rem;
  border-top: 1px solid var(--gray-800);
  text-align: center;
}

.footer-bottom p {
  font-size: 0.875rem;
  color: var(--gray-500);
}

@media (min-width: 768px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr 1fr 1fr;
  }
}

/* ===== Animations ===== */
@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

@keyframes slideUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes pulse {
  0%, 100% {
    opacity: 0.3;
    transform: scale(1);
  }
  50% {
    opacity: 0.5;
    transform: scale(1.05);
  }
}

/* Animation classes for scroll reveal */
.animate-on-scroll {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.animate-on-scroll.visible {
  opacity: 1;
  transform: translateY(0);
}