/* DONGBA LIMITED - Modern Dark Theme */
:root {
  --bg-primary: #0f0f1a;
  --bg-secondary: #1a1a2e;
  --bg-card: #16213e;
  --text-primary: #eaeaea;
  --text-secondary: #a0a0b8;
  --accent: #7c5cfc;
  --accent-dim: rgba(124, 92, 252, 0.1);
  --nav-bg: rgba(15, 15, 26, 0.95);
  --border-color: rgba(124, 92, 252, 0.2);
  --font-mono: 'SF Mono', 'Fira Code', 'Fira Mono', 'Roboto Mono', monospace;
  --font-sans: 'Inter', 'Segoe UI', 'Roboto', -apple-system, sans-serif;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-sans);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

nav {
  position: fixed;
  top: 0;
  width: 100%;
  background: var(--nav-bg);
  backdrop-filter: blur(12px);
  z-index: 1000;
  border-bottom: 1px solid var(--border-color);
}

.nav-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 72px;
}

.nav-logo {
  font-family: var(--font-mono);
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--accent);
  text-decoration: none;
  letter-spacing: 2px;
}

.nav-links {
  display: flex;
  gap: 36px;
  list-style: none;
}

.nav-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.85rem;
  font-family: var(--font-mono);
  transition: color 0.3s;
  position: relative;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--accent);
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent);
  transition: width 0.3s;
}

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

.mobile-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.mobile-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--accent);
  transition: all 0.3s;
}

.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: 0 24px;
  max-width: 1200px;
  margin: 0 auto;
  position: relative;
}

.hero::before {
  content: '';
  position: absolute;
  top: 50%;
  right: -10%;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(124, 92, 252, 0.08) 0%, transparent 70%);
  transform: translateY(-50%);
  pointer-events: none;
}

.hero-content {
  max-width: 680px;
  position: relative;
}

.hero-greeting {
  font-family: var(--font-mono);
  color: var(--accent);
  font-size: 0.9rem;
  margin-bottom: 20px;
  letter-spacing: 3px;
}

.hero-title {
  font-size: clamp(2.8rem, 7vw, 4.5rem);
  font-weight: 800;
  line-height: 1.1;
  margin-bottom: 16px;
}

.hero-title .highlight {
  color: var(--accent);
}

.hero-subtitle {
  font-size: clamp(1.1rem, 2.5vw, 1.5rem);
  color: var(--text-secondary);
  font-weight: 400;
  margin-bottom: 24px;
}

.hero-desc {
  color: var(--text-secondary);
  font-size: 1rem;
  max-width: 540px;
  margin-bottom: 40px;
  line-height: 1.8;
}

.hero-desc em {
  color: var(--accent);
  font-style: normal;
}

.btn {
  display: inline-block;
  padding: 14px 32px;
  border: 1px solid var(--accent);
  color: var(--accent);
  background: transparent;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  text-decoration: none;
  cursor: pointer;
  transition: all 0.3s;
  border-radius: 6px;
}

.btn:hover {
  background: var(--accent-dim);
  transform: translateY(-2px);
  box-shadow: 0 4px 20px rgba(124, 92, 252, 0.2);
}

.btn-primary {
  background: var(--accent-dim);
}

.section {
  padding: 100px 24px;
  max-width: 1200px;
  margin: 0 auto;
}

.section-header {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 56px;
}

.section-number {
  font-family: var(--font-mono);
  color: var(--accent);
  font-size: 1rem;
}

.section-title {
  font-size: clamp(1.5rem, 4vw, 2rem);
  font-weight: 600;
  white-space: nowrap;
}

.section-line {
  flex: 1;
  height: 1px;
  background: linear-gradient(to right, var(--border-color), transparent);
}

.services-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
}

.service-card {
  background: var(--bg-secondary);
  padding: 36px;
  border-radius: 12px;
  border: 1px solid var(--border-color);
  transition: all 0.4s;
  position: relative;
  overflow: hidden;
}

.service-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 3px;
  height: 0;
  background: var(--accent);
  transition: height 0.4s;
}

.service-card:hover::before {
  height: 100%;
}

.service-card:hover {
  transform: translateY(-6px);
  border-color: var(--accent);
  box-shadow: 0 8px 30px rgba(124, 92, 252, 0.1);
}

.service-card .icon {
  font-size: 2rem;
  margin-bottom: 16px;
  display: block;
}

.service-card h3 {
  font-size: 1.15rem;
  margin-bottom: 12px;
  color: var(--text-primary);
  font-weight: 600;
}

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

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

.about-text p {
  color: var(--text-secondary);
  margin-bottom: 16px;
  line-height: 1.8;
}

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

.about-stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.stat-card {
  background: var(--bg-secondary);
  padding: 24px;
  border-radius: 10px;
  border: 1px solid var(--border-color);
  text-align: center;
}

.stat-number {
  font-family: var(--font-mono);
  font-size: 2rem;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 4px;
}

.stat-label {
  font-size: 0.8rem;
  color: var(--text-secondary);
}

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

.contact-info-item {
  display: flex;
  gap: 16px;
  margin-bottom: 28px;
}

.contact-info-item .icon {
  color: var(--accent);
  font-size: 1.2rem;
  min-width: 28px;
  margin-top: 2px;
}

.contact-info-item h4 {
  font-size: 0.95rem;
  margin-bottom: 4px;
  font-weight: 600;
}

.contact-info-item p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.5;
}

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

.contact-form label {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--accent);
  margin-bottom: 8px;
}

.contact-form input,
.contact-form textarea {
  width: 100%;
  padding: 12px 16px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 6px;
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 0.95rem;
  transition: border-color 0.3s;
}

.contact-form input:focus,
.contact-form textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(124, 92, 252, 0.1);
}

.contact-form textarea {
  min-height: 140px;
  resize: vertical;
}

footer {
  border-top: 1px solid var(--border-color);
  padding: 40px 24px;
  text-align: center;
}

.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: 28px;
  margin-bottom: 20px;
  flex-wrap: wrap;
}

.footer-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  transition: color 0.3s;
}

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

.footer-copy {
  color: var(--text-secondary);
  font-size: 0.8rem;
}

.content-page {
  padding: 130px 24px 60px;
  max-width: 800px;
  margin: 0 auto;
}

.content-page h1 {
  font-size: 2rem;
  margin-bottom: 8px;
  color: var(--accent);
}

.content-page .last-updated {
  color: var(--text-secondary);
  font-size: 0.85rem;
  margin-bottom: 40px;
  font-family: var(--font-mono);
}

.content-page h2 {
  font-size: 1.3rem;
  margin: 36px 0 12px;
  color: var(--text-primary);
}

.content-page h3 {
  font-size: 1.1rem;
  margin: 24px 0 8px;
  color: var(--text-primary);
}

.content-page p {
  color: var(--text-secondary);
  margin-bottom: 12px;
  line-height: 1.8;
}

.content-page ul {
  color: var(--text-secondary);
  margin: 12px 0 12px 24px;
  line-height: 1.8;
}

.content-page li {
  margin-bottom: 6px;
}

.content-page a {
  color: var(--accent);
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 72px;
    left: 0;
    width: 100%;
    background: var(--nav-bg);
    flex-direction: column;
    padding: 24px;
    gap: 20px;
    border-bottom: 1px solid var(--border-color);
  }

  .nav-links.open {
    display: flex;
  }

  .mobile-toggle {
    display: flex;
  }

  .about-content,
  .contact-grid {
    grid-template-columns: 1fr;
  }

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

  .hero {
    padding-top: 80px;
  }
}