/* ===== CSS Variables ===== */
:root {
  --color-primary: #2563eb;
  --color-primary-dark: #1d4ed8;
  --color-primary-light: #3b82f6;
  --color-accent: #06b6d4;
  --color-bg: #0f172a;
  --color-bg-light: #1e293b;
  --color-bg-card: #1e293b;
  --color-text: #f1f5f9;
  --color-text-muted: #94a3b8;
  --color-border: rgba(148, 163, 184, 0.15);
  --gradient-primary: linear-gradient(135deg, #2563eb 0%, #06b6d4 100%);
  --gradient-hero: linear-gradient(135deg, #0f172a 0%, #1e3a5f 50%, #0f172a 100%);
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 10px 40px rgba(37, 99, 235, 0.15);
  --radius: 12px;
  --radius-lg: 20px;
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --header-height: 72px;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--header-height);
}

body {
  font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.7;
  overflow-x: hidden;
}

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

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

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== Header ===== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  z-index: 1000;
  transition: var(--transition);
  background: transparent;
}

.header.scrolled {
  background: rgba(15, 23, 42, 0.95);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
  font-size: 1.15rem;
}

.logo-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  background: var(--gradient-primary);
  border-radius: 10px;
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: -0.5px;
}

.nav {
  display: flex;
  gap: 8px;
}

.nav-link {
  padding: 8px 16px;
  border-radius: 8px;
  font-size: 0.95rem;
  color: var(--color-text-muted);
  transition: var(--transition);
}

.nav-link:hover,
.nav-link.active {
  color: var(--color-text);
  background: rgba(255, 255, 255, 0.06);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: var(--transition);
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 28px;
  border-radius: 10px;
  font-size: 0.95rem;
  font-weight: 500;
  cursor: pointer;
  border: none;
  transition: var(--transition);
  font-family: inherit;
}

.btn-primary {
  background: var(--gradient-primary);
  color: #fff;
  box-shadow: 0 4px 15px rgba(37, 99, 235, 0.35);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 25px rgba(37, 99, 235, 0.45);
}

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

.btn-outline:hover {
  background: rgba(255, 255, 255, 0.06);
  border-color: rgba(148, 163, 184, 0.3);
}

.btn-full {
  width: 100%;
}

/* ===== Hero ===== */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: calc(var(--header-height) + 40px) 0 80px;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background: var(--gradient-hero);
}

.hero-bg::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 60% at 50% 0%, rgba(37, 99, 235, 0.2) 0%, transparent 60%),
    radial-gradient(ellipse 60% 40% at 80% 80%, rgba(6, 182, 212, 0.12) 0%, transparent 50%);
}

.hero-bg::after {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(148, 163, 184, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(148, 163, 184, 0.03) 1px, transparent 1px);
  background-size: 60px 60px;
  mask-image: radial-gradient(ellipse at center, black 30%, transparent 70%);
}

.hero-content {
  position: relative;
  text-align: center;
  z-index: 1;
}

.hero-badge {
  display: inline-block;
  padding: 6px 16px;
  background: rgba(37, 99, 235, 0.15);
  border: 1px solid rgba(37, 99, 235, 0.3);
  border-radius: 50px;
  font-size: 0.85rem;
  color: var(--color-primary-light);
  margin-bottom: 24px;
}

.hero-title {
  font-size: clamp(2rem, 5vw, 3.2rem);
  font-weight: 700;
  line-height: 1.25;
  margin-bottom: 20px;
  background: linear-gradient(135deg, #fff 0%, #94a3b8 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: clamp(1rem, 2vw, 1.2rem);
  color: var(--color-text-muted);
  max-width: 600px;
  margin: 0 auto 36px;
  line-height: 1.8;
}

.hero-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 60px;
}

.hero-stats {
  display: flex;
  gap: 48px;
  justify-content: center;
  flex-wrap: wrap;
}

.stat-item {
  display: flex;
  flex-direction: column;
  align-items: center;
}

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

.stat-label {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  margin-top: 4px;
}

.hero-scroll {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  color: var(--color-text-muted);
  font-size: 0.8rem;
  animation: float 2s ease-in-out infinite;
}

.scroll-arrow {
  width: 20px;
  height: 20px;
  border-right: 2px solid var(--color-text-muted);
  border-bottom: 2px solid var(--color-text-muted);
  transform: rotate(45deg);
}

@keyframes float {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50% { transform: translateX(-50%) translateY(8px); }
}

/* ===== Sections ===== */
.section {
  padding: 100px 0;
}

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

.section-tag {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: 12px;
}

.section-title {
  font-size: clamp(1.8rem, 3vw, 2.4rem);
  font-weight: 700;
  margin-bottom: 16px;
}

.section-desc {
  color: var(--color-text-muted);
  font-size: 1.05rem;
  max-width: 500px;
  margin: 0 auto;
}

/* ===== About ===== */
.about {
  background: var(--color-bg-light);
}

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

.about-text {
  color: var(--color-text-muted);
  margin-bottom: 16px;
  font-size: 1rem;
}

.about-text strong {
  color: var(--color-text);
}

.about-info {
  margin-top: 32px;
  display: grid;
  gap: 12px;
}

.info-item {
  display: flex;
  flex-direction: column;
  padding: 12px 16px;
  background: rgba(255, 255, 255, 0.03);
  border-radius: 8px;
  border: 1px solid var(--color-border);
}

.info-label {
  font-size: 0.8rem;
  color: var(--color-text-muted);
  margin-bottom: 4px;
}

.info-value {
  font-size: 0.95rem;
  color: var(--color-text);
}

.about-visual {
  display: grid;
  gap: 20px;
}

.about-card {
  padding: 28px;
  background: var(--color-bg);
  border-radius: var(--radius);
  border: 1px solid var(--color-border);
  transition: var(--transition);
}

.about-card:hover {
  border-color: rgba(37, 99, 235, 0.3);
  transform: translateX(8px);
}

.about-card-icon {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(37, 99, 235, 0.12);
  border-radius: 12px;
  margin-bottom: 16px;
  color: var(--color-primary-light);
}

.about-card-icon svg {
  width: 24px;
  height: 24px;
}

.about-card h3 {
  font-size: 1.1rem;
  margin-bottom: 8px;
}

.about-card p {
  font-size: 0.9rem;
  color: var(--color-text-muted);
}

/* ===== Services ===== */
.services-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.service-card {
  padding: 32px 28px;
  background: var(--color-bg-card);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  transition: var(--transition);
}

.service-card:hover {
  transform: translateY(-6px);
  border-color: rgba(37, 99, 235, 0.3);
  box-shadow: var(--shadow-lg);
}

.service-icon {
  width: 52px;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--gradient-primary);
  border-radius: 14px;
  margin-bottom: 20px;
  color: #fff;
}

.service-icon svg {
  width: 26px;
  height: 26px;
}

.service-card h3 {
  font-size: 1.15rem;
  margin-bottom: 12px;
}

.service-card p {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  line-height: 1.7;
}

/* ===== Advantages ===== */
.advantages {
  background: var(--color-bg-light);
}

.advantages-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
}

.advantage-item {
  text-align: center;
  padding: 32px 20px;
}

.advantage-number {
  font-size: 3rem;
  font-weight: 700;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  opacity: 0.3;
  line-height: 1;
  margin-bottom: 16px;
}

.advantage-item h3 {
  font-size: 1.1rem;
  margin-bottom: 12px;
}

.advantage-item p {
  font-size: 0.9rem;
  color: var(--color-text-muted);
}

/* ===== Contact ===== */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
}

.contact-info {
  display: flex;
  flex-direction: column;
  gap: 28px;
}

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

.contact-icon {
  flex-shrink: 0;
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(37, 99, 235, 0.12);
  border-radius: 12px;
  color: var(--color-primary-light);
}

.contact-icon svg {
  width: 22px;
  height: 22px;
}

.contact-item h4 {
  font-size: 1rem;
  margin-bottom: 6px;
}

.contact-item p {
  font-size: 0.9rem;
  color: var(--color-text-muted);
}

.contact-form {
  padding: 36px;
  background: var(--color-bg-light);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
}

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

.form-group label {
  display: block;
  font-size: 0.9rem;
  margin-bottom: 8px;
  color: var(--color-text-muted);
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 12px 16px;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  color: var(--color-text);
  font-size: 0.95rem;
  font-family: inherit;
  transition: var(--transition);
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

.form-group textarea {
  resize: vertical;
  min-height: 100px;
}

.form-note {
  margin-top: 12px;
  font-size: 0.8rem;
  color: var(--color-text-muted);
  text-align: center;
}

/* ===== Footer ===== */
.footer {
  background: #0a0f1a;
  padding: 60px 0 30px;
  border-top: 1px solid var(--color-border);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.5fr;
  gap: 40px;
  margin-bottom: 40px;
}

.footer-brand p {
  margin-top: 16px;
  font-size: 0.9rem;
  color: var(--color-text-muted);
  line-height: 1.8;
}

.footer-links h4,
.footer-contact h4 {
  font-size: 0.95rem;
  margin-bottom: 16px;
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-links a {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  transition: var(--transition);
}

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

.footer-contact p {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  margin-bottom: 8px;
}

.footer-bottom {
  padding-top: 30px;
  border-top: 1px solid var(--color-border);
  text-align: center;
}

.footer-bottom p {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  margin-bottom: 6px;
}

.footer-bottom .icp a {
  color: var(--color-text-muted);
  transition: var(--transition);
}

.footer-bottom .icp a:hover {
  color: var(--color-primary-light);
}

/* ===== Back to Top ===== */
.back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 44px;
  height: 44px;
  background: var(--gradient-primary);
  border: none;
  border-radius: 12px;
  color: #fff;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
  transition: var(--transition);
  z-index: 999;
  box-shadow: var(--shadow-md);
}

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

.back-to-top svg {
  width: 20px;
  height: 20px;
}

.back-to-top:hover {
  transform: translateY(-4px);
}

/* ===== Animations ===== */
.fade-in {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

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

/* ===== Responsive ===== */
@media (max-width: 1024px) {
  .services-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .advantages-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .footer-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .nav {
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    background: rgba(15, 23, 42, 0.98);
    backdrop-filter: blur(12px);
    flex-direction: column;
    padding: 20px;
    gap: 4px;
    border-bottom: 1px solid var(--color-border);
    transform: translateY(-120%);
    opacity: 0;
    transition: var(--transition);
  }

  .nav.open {
    transform: translateY(0);
    opacity: 1;
  }

  .nav-link {
    padding: 12px 16px;
  }

  .nav-toggle {
    display: flex;
  }

  .nav-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
  }

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

  .nav-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
  }

  .about-grid,
  .contact-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .services-grid {
    grid-template-columns: 1fr;
  }

  .advantages-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 30px;
  }

  .hero-stats {
    gap: 32px;
  }

  .section {
    padding: 70px 0;
  }
}

@media (max-width: 480px) {
  .hero-actions {
    flex-direction: column;
    align-items: center;
  }

  .btn {
    width: 100%;
    max-width: 280px;
  }

  .contact-form {
    padding: 24px;
  }
}