/* Aurora Northern Lights (北极光幕流动) Theme */
:root {
  --aurora-night: #05131D;
  --aurora-deep: #0B2535;
  --aurora-mid: #133A4F;
  --aurora-green: #00FF87;
  --aurora-teal: #52B788;
  --aurora-cyan: #64DFDF;
  --aurora-blue: #48CAE4;
  --aurora-light-bg: #F0FDF8;
  --aurora-panel-bg: #E3F6F3;
  --aurora-card-light: #FFFFFF;
  --aurora-card-dark: rgba(11, 37, 53, 0.7);
  --aurora-text-dark: #0B2535;
  --aurora-text-muted: #3D6175;
  --aurora-text-light: #E0F2FE;
  --aurora-glow: rgba(0, 255, 135, 0.35);
  --aurora-shadow: 0 10px 30px rgba(5, 19, 29, 0.12);
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background-color: var(--aurora-light-bg);
  color: var(--aurora-text-dark);
  line-height: 1.6;
  overflow-x: hidden;
}

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

h1, h2, h3, h4 {
  font-weight: 700;
  line-height: 1.25;
}

a {
  text-decoration: none;
  color: inherit;
  transition: var(--transition);
}

/* Header / Navigation */
.header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(5, 19, 29, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(0, 255, 135, 0.15);
  padding: 16px 0;
}

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

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 22px;
  font-weight: 800;
  color: var(--aurora-green);
  letter-spacing: -0.5px;
}

.logo-icon {
  width: 38px;
  height: 38px;
  background: linear-gradient(135deg, var(--aurora-green), var(--aurora-cyan));
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--aurora-night);
  font-size: 20px;
  font-weight: bold;
  box-shadow: 0 4px 12px rgba(0, 255, 135, 0.3);
}

.nav {
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav-link {
  color: var(--aurora-text-light);
  font-size: 15px;
  font-weight: 500;
  position: relative;
  opacity: 0.85;
}

.nav-link:hover, .nav-link.active {
  color: var(--aurora-green);
  opacity: 1;
}

.nav-link.active::after {
  content: "";
  position: absolute;
  bottom: -6px;
  left: 0;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, var(--aurora-green), var(--aurora-cyan));
  border-radius: 2px;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 26px;
  font-size: 15px;
  font-weight: 600;
  border-radius: 30px;
  cursor: pointer;
  border: none;
  transition: var(--transition);
  white-space: nowrap;
}

.btn-primary {
  background: linear-gradient(135deg, var(--aurora-green), var(--aurora-cyan));
  color: var(--aurora-night);
  box-shadow: 0 10px 25px rgba(0, 255, 135, 0.3);
}

.btn-primary:hover {
  transform: translateY(-2px);
  background: linear-gradient(135deg, var(--aurora-cyan), var(--aurora-blue));
  color: var(--aurora-night);
  box-shadow: 0 15px 30px rgba(100, 223, 223, 0.4);
}

.btn-outline {
  background: rgba(255, 255, 255, 0.08);
  color: var(--aurora-text-light);
  border: 1px solid rgba(0, 255, 135, 0.3);
}

.btn-outline:hover {
  background: rgba(0, 255, 135, 0.2);
  color: var(--aurora-green);
  border-color: var(--aurora-green);
  transform: translateY(-2px);
}

/* Hero Section */
.hero {
  position: relative;
  background: linear-gradient(180deg, var(--aurora-night) 0%, var(--aurora-deep) 50%, var(--aurora-mid) 100%);
  color: var(--aurora-text-light);
  padding: 90px 0 100px;
  overflow: hidden;
  text-align: center;
}

.aurora-glow-bg {
  position: absolute;
  top: -30%;
  left: 50%;
  transform: translateX(-50%);
  width: 900px;
  height: 900px;
  background: radial-gradient(circle, rgba(0, 255, 135, 0.18) 0%, rgba(100, 223, 223, 0.1) 50%, transparent 75%);
  pointer-events: none;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 20px;
  background: rgba(0, 255, 135, 0.12);
  border: 1px solid rgba(0, 255, 135, 0.3);
  border-radius: 20px;
  color: var(--aurora-green);
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 24px;
  backdrop-filter: blur(6px);
}

.hero-title {
  font-size: 48px;
  letter-spacing: -1px;
  margin-bottom: 20px;
  max-width: 900px;
  margin-left: auto;
  margin-right: auto;
}

.hero-title span {
  background: linear-gradient(135deg, var(--aurora-green), var(--aurora-cyan), var(--aurora-blue));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-subtitle {
  font-size: 18px;
  color: rgba(224, 242, 254, 0.85);
  max-width: 750px;
  margin: 0 auto 36px;
  line-height: 1.7;
}

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

.hero-showcase {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: 20px;
}

.hero-card {
  background: var(--aurora-card-dark);
  border: 1px solid rgba(0, 255, 135, 0.2);
  border-radius: var(--radius-md);
  padding: 14px;
  backdrop-filter: blur(10px);
  transition: var(--transition);
}

.hero-card:hover {
  transform: translateY(-6px);
  border-color: var(--aurora-green);
  box-shadow: 0 12px 30px rgba(0, 255, 135, 0.25);
}

.hero-card img {
  width: 100%;
  height: 220px;
  object-fit: cover;
  border-radius: var(--radius-sm);
  display: block;
}

.hero-card-caption {
  margin-top: 12px;
  font-size: 14px;
  font-weight: 600;
  color: var(--aurora-green);
}

/* Section Shared */
.section {
  padding: 90px 0;
}

.section-panel {
  background: var(--aurora-panel-bg);
}

.section-title {
  text-align: center;
  margin-bottom: 56px;
}

.section-title h2 {
  font-size: 36px;
  color: var(--aurora-text-dark);
  margin-bottom: 12px;
  letter-spacing: -0.5px;
}

.section-title p {
  font-size: 16px;
  color: var(--aurora-text-muted);
  max-width: 600px;
  margin: 0 auto;
}

/* Features 3x3 Grid */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.feature-card {
  background: var(--aurora-card-light);
  border: 1px solid rgba(82, 183, 136, 0.2);
  border-radius: var(--radius-md);
  padding: 32px 28px;
  transition: var(--transition);
  box-shadow: var(--aurora-shadow);
  position: relative;
  overflow: hidden;
}

.feature-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: linear-gradient(90deg, var(--aurora-green), var(--aurora-cyan), var(--aurora-blue));
  opacity: 0;
  transition: var(--transition);
}

.feature-card:hover {
  transform: translateY(-8px);
  box-shadow: 0 20px 40px rgba(11, 37, 53, 0.15);
  border-color: rgba(0, 255, 135, 0.4);
}

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

.feature-num {
  font-size: 28px;
  font-weight: 800;
  color: var(--aurora-teal);
  margin-bottom: 14px;
}

.feature-card h3 {
  font-size: 20px;
  color: var(--aurora-text-dark);
  margin-bottom: 12px;
}

.feature-card p {
  font-size: 14px;
  color: var(--aurora-text-muted);
  line-height: 1.7;
}

/* Blog / Tutorials Section */
.blog-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 30px;
}

.blog-card {
  background: var(--aurora-card-light);
  border-radius: var(--radius-md);
  padding: 28px;
  border: 1px solid rgba(82, 183, 136, 0.2);
  box-shadow: var(--aurora-shadow);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: var(--transition);
}

.blog-card:hover {
  transform: translateY(-6px);
  border-color: var(--aurora-cyan);
  box-shadow: 0 16px 36px rgba(100, 223, 223, 0.2);
}

.blog-date {
  font-size: 13px;
  color: var(--aurora-teal);
  font-weight: 600;
  margin-bottom: 10px;
}

.blog-card h3 {
  font-size: 18px;
  color: var(--aurora-text-dark);
  margin-bottom: 12px;
}

.blog-card p {
  font-size: 14px;
  color: var(--aurora-text-muted);
  margin-bottom: 20px;
  line-height: 1.6;
}

.blog-link {
  font-size: 14px;
  font-weight: 700;
  color: var(--aurora-teal);
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.blog-link:hover {
  color: var(--aurora-blue);
}

.more-wrapper {
  text-align: center;
  margin-top: 40px;
}

/* FAQ Section */
.faq-container {
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.faq-item {
  background: var(--aurora-card-light);
  border: 1px solid rgba(82, 183, 136, 0.2);
  border-radius: var(--radius-md);
  padding: 24px 28px;
  box-shadow: var(--aurora-shadow);
  transition: var(--transition);
}

.faq-item:hover {
  border-color: var(--aurora-cyan);
  transform: translateY(-2px);
}

.faq-question {
  font-size: 17px;
  font-weight: 700;
  color: var(--aurora-deep);
  margin-bottom: 10px;
}

.faq-answer {
  font-size: 15px;
  color: var(--aurora-text-muted);
  line-height: 1.7;
}

/* Download Cards Section */
.download-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  margin-bottom: 40px;
}

.download-card {
  background: var(--aurora-card-light);
  border-radius: var(--radius-md);
  padding: 36px 28px;
  text-align: center;
  border: 1px solid rgba(82, 183, 136, 0.2);
  box-shadow: var(--aurora-shadow);
  transition: var(--transition);
}

.download-card:hover {
  transform: translateY(-8px);
  border-color: var(--aurora-cyan);
  box-shadow: 0 20px 40px rgba(11, 37, 53, 0.18);
}

.download-card-icon {
  width: 64px;
  height: 64px;
  background: linear-gradient(135deg, var(--aurora-light-bg), var(--aurora-panel-bg));
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 20px;
  font-size: 28px;
  color: var(--aurora-teal);
}

.download-card h3 {
  font-size: 20px;
  color: var(--aurora-text-dark);
  margin-bottom: 12px;
}

.download-card p {
  font-size: 14px;
  color: var(--aurora-text-muted);
  margin-bottom: 24px;
  line-height: 1.6;
}

.download-web-banner {
  background: linear-gradient(135deg, var(--aurora-deep), var(--aurora-mid));
  color: var(--aurora-text-light);
  border-radius: var(--radius-md);
  padding: 36px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border: 1px solid rgba(0, 255, 135, 0.2);
  gap: 24px;
}

.download-web-banner h3 {
  font-size: 22px;
  color: var(--aurora-green);
  margin-bottom: 8px;
}

.download-web-banner p {
  font-size: 15px;
  color: rgba(224, 242, 254, 0.85);
}

/* Footer */
.footer {
  background: var(--aurora-night);
  color: var(--aurora-text-light);
  padding: 70px 0 30px;
  border-top: 1px solid rgba(0, 255, 135, 0.12);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr repeat(3, 1fr);
  gap: 40px;
  margin-bottom: 50px;
}

.footer-col h4 {
  font-size: 16px;
  color: var(--aurora-green);
  margin-bottom: 20px;
}

.footer-col p {
  font-size: 14px;
  color: rgba(224, 242, 254, 0.7);
  line-height: 1.7;
}

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

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

.footer-col a {
  font-size: 14px;
  color: rgba(224, 242, 254, 0.75);
}

.footer-col a:hover {
  color: var(--aurora-green);
}

.footer-copyright {
  text-align: center;
  padding-top: 30px;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  font-size: 13px;
  color: rgba(224, 242, 254, 0.5);
}

/* Responsive */
@media (max-width: 992px) {
  .hero-title {
    font-size: 36px;
  }
  .features-grid, .download-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .hero-showcase {
    grid-template-columns: 1fr;
  }
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
  .download-web-banner {
    flex-direction: column;
    text-align: center;
  }
}

@media (max-width: 600px) {
  .nav {
    display: none;
  }
  .hero-title {
    font-size: 28px;
  }
  .features-grid, .download-grid, .blog-grid {
    grid-template-columns: 1fr;
  }
  .footer-grid {
    grid-template-columns: 1fr;
  }
}