@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;600;800&display=swap');
@import url('https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.4.0/css/all.min.css');

:root {
  --primary: #DDA0DD;
  --primary-glow: rgba(221, 160, 221, 0.4);
  --bg-dark: #09090E;
  --bg-card: rgba(255, 255, 255, 0.03);
  --bg-card-hover: rgba(255, 255, 255, 0.08);
  --text-main: #FFFFFF;
  --text-muted: #A0A0B0;
  --glass-border: rgba(255, 255, 255, 0.1);
  --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

html {
  scroll-behavior: smooth;
}

body {
  background-color: var(--bg-dark);
  color: var(--text-main);
  line-height: 1.6;
  overflow-x: hidden;
  background-image: 
    radial-gradient(circle at 15% 50%, rgba(221, 160, 221, 0.08), transparent 25%),
    radial-gradient(circle at 85% 30%, rgba(221, 160, 221, 0.1), transparent 25%);
  background-attachment: fixed;
}

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

a:hover {
  text-shadow: 0 0 8px var(--primary-glow);
}

/* Typography */
h1, h2, h3, h4 {
  font-weight: 800;
  line-height: 1.2;
}

.section-title {
  text-align: center;
  font-size: 2.5rem;
  margin-bottom: 1rem;
  background: linear-gradient(to right, #fff, var(--primary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.section-desc {
  text-align: center;
  color: var(--text-muted);
  max-width: 600px;
  margin: 0 auto 4rem auto;
  font-size: 1.1rem;
}

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

section {
  padding: 100px 0;
  position: relative;
}

/* Buttons */
.btn {
  display: inline-block;
  padding: 12px 28px;
  border-radius: 30px;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  text-align: center;
  border: none;
  text-decoration: none;
}

.btn-primary {
  background: var(--primary);
  color: var(--bg-dark);
  box-shadow: 0 0 15px var(--primary-glow);
}

.btn-primary:hover {
  transform: translateY(-3px);
  box-shadow: 0 0 25px var(--primary-glow);
  color: var(--bg-dark);
  text-shadow: none;
}

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

.btn-outline:hover {
  background: rgba(221, 160, 221, 0.1);
  transform: translateY(-3px);
}

/* Navbar */
header {
  position: fixed;
  top: 0;
  width: 100%;
  padding: 20px 0;
  z-index: 1000;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--glass-border);
  background: rgba(9, 9, 14, 0.8);
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--primary);
  display: flex;
  align-items: center;
  gap: 10px;
}

.logo span {
  color: #fff;
}

.nav-links {
  display: flex;
  gap: 30px;
  list-style: none;
}

.nav-links a {
  color: var(--text-muted);
  font-weight: 600;
  font-size: 0.95rem;
}

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

.mobile-menu-btn {
  display: none;
  font-size: 1.5rem;
  color: white;
  cursor: pointer;
}

/* Hero Section */
.hero {
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding-top: 80px;
  position: relative;
}

.hero::before {
  content: '';
  position: absolute;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, var(--primary-glow) 0%, transparent 70%);
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  z-index: -1;
  animation: pulse 6s infinite alternate;
}

.hero-title {
  font-size: 4.5rem;
  margin-bottom: 20px;
  background: linear-gradient(135deg, #fff 0%, var(--primary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  animation: fadeInUp 1s ease;
}

.hero-subtitle {
  font-size: 1.2rem;
  color: var(--text-muted);
  margin-bottom: 40px;
  max-width: 800px;
  margin-left: auto;
  margin-right: auto;
  animation: fadeInUp 1s ease 0.2s both;
}

.hero-cta {
  display: flex;
  gap: 20px;
  justify-content: center;
  animation: fadeInUp 1s ease 0.4s both;
}

/* Features */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 30px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--glass-border);
  border-radius: 20px;
  padding: 40px 30px;
  text-align: center;
  backdrop-filter: blur(10px);
  transition: var(--transition);
}

.feature-card:hover {
  transform: translateY(-10px);
  background: var(--bg-card-hover);
  border-color: var(--primary);
  box-shadow: 0 10px 30px rgba(0,0,0,0.5);
}

.feature-icon {
  font-size: 3rem;
  color: var(--primary);
  margin-bottom: 20px;
  display: inline-block;
  background: -webkit-linear-gradient(top, #fff, var(--primary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.feature-card h3 {
  font-size: 1.5rem;
  margin-bottom: 15px;
}

.feature-card p {
  color: var(--text-muted);
  font-size: 0.95rem;
}

/* Scene Search (Use Cases) */
.scene-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 20px;
}

.scene-card {
  position: relative;
  border-radius: 20px;
  overflow: hidden;
  height: 200px;
  display: flex;
  align-items: flex-end;
  padding: 20px;
  border: 1px solid var(--glass-border);
  transition: var(--transition);
}
.scene-card:hover {
  transform: scale(1.03);
  border-color: var(--primary);
}
.scene-card::before {
  content: '';
  position: absolute;
  top:0; left:0; width:100%; height:100%;
  background: linear-gradient(to top, rgba(9,9,14,0.9), transparent);
  z-index: 1;
}
.scene-card img {
  position: absolute;
  top: 0; left: 0; width: 100%; height: 100%;
  object-fit: cover;
  z-index: 0;
  opacity: 0.5;
  transition: var(--transition);
}
.scene-card:hover img {
  opacity: 0.8;
}
.scene-content {
  position: relative;
  z-index: 2;
}
.scene-content h3 {
  font-size: 1.3rem;
  margin-bottom: 5px;
}
.scene-content p {
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* Pricing */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 30px;
  align-items: center;
}

.price-card {
  background: var(--bg-card);
  border: 1px solid var(--glass-border);
  border-radius: 24px;
  padding: 50px 40px;
  text-align: center;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.price-card.popular {
  border-color: var(--primary);
  background: rgba(221, 160, 221, 0.05);
  transform: scale(1.05);
}

.price-card.popular::before {
  content: '最具性价比';
  position: absolute;
  top: 25px;
  right: -40px;
  background: var(--primary);
  color: var(--bg-dark);
  padding: 5px 40px;
  transform: rotate(45deg);
  font-weight: bold;
  font-size: 0.85rem;
  z-index: 10;
}

.price-card:hover {
  transform: translateY(-10px) scale(1.05);
  box-shadow: 0 15px 40px rgba(221, 160, 221, 0.15);
}

.price-card:not(.popular):hover {
  transform: translateY(-10px);
}

.plan-name {
  font-size: 1.5rem;
  color: #fff;
  margin-bottom: 15px;
}

.price {
  font-size: 3.5rem;
  font-weight: 800;
  margin-bottom: 20px;
  color: var(--primary);
}

.price span {
  font-size: 1rem;
  color: var(--text-muted);
}

.plan-features {
  list-style: none;
  margin-bottom: 40px;
  text-align: left;
}

.plan-features li {
  margin-bottom: 15px;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 10px;
}

.plan-features li i {
  color: var(--primary);
  font-size: 1.1rem;
}

.price-card .btn {
  width: 100%;
}

/* Tutorials & Speed Test */
.tutorial-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.tut-card {
  background: var(--bg-card);
  padding: 30px;
  border-radius: 16px;
  text-align: center;
  border: 1px solid var(--glass-border);
  transition: var(--transition);
  color: white;
}

.tut-card:hover {
  background: rgba(221, 160, 221, 0.1);
  border-color: var(--primary);
  transform: translateY(-5px);
}

.tut-card i {
  font-size: 2.5rem;
  color: var(--primary);
  margin-bottom: 15px;
}

/* Speed Test */
.speed-test-container {
  background: var(--bg-card);
  border: 1px solid var(--glass-border);
  border-radius: 20px;
  padding: 40px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}
.speed-bar {
  display: flex;
  align-items: center;
  gap: 15px;
}
.speed-label { width: 100px; font-weight: 600; }
.progress {
  flex: 1;
  height: 10px;
  background: rgba(255,255,255,0.1);
  border-radius: 5px;
  overflow: hidden;
}
.progress-inner {
  height: 100%;
  background: linear-gradient(90deg, #fff, var(--primary));
  border-radius: 5px;
  position: relative;
}
.speed-value { width: 80px; text-align: right; font-family: monospace; color: var(--primary); }

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

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--glass-border);
  border-radius: 12px;
  margin-bottom: 15px;
  overflow: hidden;
}

.faq-q {
  padding: 20px;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-weight: 600;
  transition: var(--transition);
}

.faq-q:hover {
  color: var(--primary);
}

.faq-a {
  padding: 0 20px;
  max-height: 0;
  overflow: hidden;
  color: var(--text-muted);
  transition: var(--transition);
}

.faq-item.active .faq-a {
  padding: 0 20px 20px 20px;
  max-height: 500px;
}

.faq-item.active .faq-q {
  color: var(--primary);
}
.faq-item.active .faq-q i {
  transform: rotate(180deg);
}

/* Reviews */
.reviews-scroll {
  display: flex;
  gap: 20px;
  overflow-x: auto;
  padding: 20px 0;
  scrollbar-width: none;
}
.reviews-scroll::-webkit-scrollbar { display: none; }

.review-card {
  min-width: 320px;
  background: var(--bg-card);
  border: 1px solid var(--glass-border);
  padding: 30px;
  border-radius: 16px;
}
.review-card .stars { color: var(--primary); margin-bottom: 15px; font-size: 1.2rem; }
.review-card p { font-size: 0.95rem; color: var(--text-muted); margin-bottom: 20px; }
.review-user { display: flex; align-items: center; gap: 15px; }
.review-user .avatar { width: 40px; height: 40px; border-radius: 50%; background: var(--primary-glow); display: flex; align-items: center; justify-content: center; font-weight: bold; color: #fff;}
.review-user .info h4 { font-size: 1rem; margin-bottom: 2px; }
.review-user .info span { font-size: 0.8rem; color: var(--text-muted); }


/* Articles / Knowledge Base */
.article-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
}
.article-item {
  background: var(--bg-card);
  border: 1px solid var(--glass-border);
  border-radius: 12px;
  padding: 25px;
  transition: var(--transition);
  display: block;
  color: var(--text-main);
}
.article-item:hover {
  border-color: var(--primary);
  transform: translateY(-5px);
  background: var(--bg-card-hover);
}
.article-item h4 {
  font-size: 1.2rem;
  margin-bottom: 15px;
  color: #fff;
  line-height: 1.4;
}
.article-item p {
  font-size: 0.9rem;
  color: var(--text-muted);
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
  margin-bottom: 15px;
}
.article-meta {
  font-size: 0.8rem;
  color: var(--primary);
  display: flex;
  justify-content: space-between;
}

/* Tags Footer */
.tags-container {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: center;
  padding: 60px 20px;
  background: rgba(0,0,0,0.4);
  border-top: 1px solid var(--glass-border);
}

.tag {
  font-size: 0.85rem;
  color: var(--text-muted);
  background: rgba(255,255,255,0.05);
  padding: 8px 16px;
  border-radius: 20px;
  border: 1px solid var(--glass-border);
  transition: var(--transition);
}

.tag:hover {
  color: var(--bg-dark);
  background: var(--primary);
  border-color: var(--primary);
}

footer {
  text-align: center;
  padding: 30px 0;
  color: var(--text-muted);
  background: #050508;
  font-size: 0.9rem;
}

/* Animations */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(30px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes pulse {
  0% { transform: translate(-50%, -50%) scale(1); opacity: 0.4; }
  100% { transform: translate(-50%, -50%) scale(1.2); opacity: 0.7; }
}

/* Mobile Responsive */
@media (max-width: 768px) {
  .hero-title { font-size: 2.8rem; }
  .hero-subtitle { font-size: 1rem; }
  .nav-links {
    position: absolute;
    top: 70px;
    left: 0;
    width: 100%;
    background: rgba(9, 9, 14, 0.95);
    flex-direction: column;
    padding: 20px;
    text-align: center;
    gap: 20px;
    display: none;
    border-bottom: 1px solid var(--glass-border);
  }
  .nav-links.active { display: flex; }
  .mobile-menu-btn { display: block; }
  .tutorial-grid { grid-template-columns: repeat(2, 1fr); }
  .hero-cta { flex-direction: column; width: 80%; margin: 0 auto; }
}