:root {
  --primary: #4F46E5;
  --primary-hover: #4338CA;
  --bg: #F9FAFB;
  --bg-light: #F3F4F6;
  --text-main: #111827;
  --text-muted: #4B5563;
  --card-bg: #FFFFFF;
  --border: #E5E7EB;
}

* { margin: 0; padding: 0; box-sizing: border-box; scroll-behavior: smooth; }
body { font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif; background-color: var(--bg); color: var(--text-main); line-height: 1.6; }
a { text-decoration: none; color: inherit; }
.container { width: 100%; max-width: 1200px; margin: 0 auto; padding: 0 20px; }
.bg-light { background-color: var(--bg-light); }

.btn { display: inline-block; background: var(--primary); color: #fff; padding: 14px 28px; border-radius: 8px; font-size: 1.1rem; font-weight: 600; text-align: center; transition: background 0.3s ease, transform 0.2s ease; }
.btn:hover { background: var(--primary-hover); transform: translateY(-2px); }

/* 导航栏 */
.navbar { position: fixed; top: 0; left: 0; right: 0; background: rgba(255, 255, 255, 0.85); backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px); z-index: 1000; border-bottom: 1px solid var(--border); }
.nav-container { display: flex; justify-content: space-between; align-items: center; max-width: 1200px; margin: 0 auto; padding: 15px 20px; }
.logo { font-size: 1.8rem; font-weight: 800; color: var(--primary); letter-spacing: 1px; }
.nav-links { display: none; gap: 30px; }
@media (min-width: 768px) { .nav-links { display: flex; } }
.nav-links a { font-weight: 600; color: var(--text-main); transition: color 0.3s; }
.nav-links a:hover { color: var(--primary); }

section { padding: 100px 0 80px; }
h2 { font-size: 2.2rem; margin-bottom: 50px; text-align: center; color: var(--text-main); }

/* 主视觉区 */
header { background: #fff; padding: 160px 20px 100px; border-bottom: 1px solid var(--border); overflow: hidden; }
.hero-grid { display: grid; grid-template-columns: 1fr; gap: 60px; align-items: center; }
@media (min-width: 992px) { .hero-grid { grid-template-columns: 1fr 1fr; } }
.hero-text h1 { font-size: 3rem; margin-bottom: 20px; color: var(--text-main); line-height: 1.2; }
.hero-text p.subtitle { font-size: 1.25rem; color: var(--text-muted); margin-bottom: 40px; }

.hero-visual { position: relative; height: 400px; display: flex; justify-content: center; align-items: center; }
.pulse-core { width: 120px; height: 120px; background: rgba(79, 70, 229, 0.1); border-radius: 50%; animation: pulse 2.5s infinite ease-out; display: flex; justify-content: center; align-items: center; }
.pulse-core::after { content: "九云"; font-size: 1.5rem; font-weight: bold; color: var(--primary); animation: none; }
@keyframes pulse { 0% { transform: scale(0.8); opacity: 1; box-shadow: 0 0 0 0 rgba(79, 70, 229, 0.4); } 70% { transform: scale(2); opacity: 0; box-shadow: 0 0 0 30px rgba(79, 70, 229, 0); } 100% { transform: scale(2.5); opacity: 0; box-shadow: 0 0 0 0 rgba(79, 70, 229, 0); } }
@keyframes floatY { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-20px); } }
.floating-card { position: absolute; background: rgba(255, 255, 255, 0.95); backdrop-filter: blur(5px); padding: 15px 25px; border-radius: 16px; box-shadow: 0 15px 30px rgba(0,0,0,0.1); display: flex; align-items: center; gap: 15px; border: 1px solid var(--border); animation: floatY 5s ease-in-out infinite; z-index: 10; }
.floating-card .icon { font-size: 1.8rem; }
.floating-card .details { display: flex; flex-direction: column; }
.floating-card .details span { font-size: 0.85rem; color: var(--text-muted); }
.floating-card .details strong { font-size: 1.1rem; color: var(--text-main); }
.card-anim-1 { top: 10%; left: 0; animation-delay: 0s; }
.card-anim-2 { bottom: 10%; right: 10%; animation-delay: 1.5s; }
.card-anim-3 { top: 40%; right: -5%; animation-delay: 0.8s; }

.grid-3 { display: grid; grid-template-columns: 1fr; gap: 30px; }
@media (min-width: 768px) { .grid-3 { grid-template-columns: repeat(3, 1fr); } }

.card { background: var(--card-bg); padding: 40px 30px; border-radius: 16px; box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05); border: 1px solid var(--border); transition: transform 0.3s ease; }
.card:hover { transform: translateY(-5px); }
.card h3 { font-size: 1.3rem; margin-bottom: 15px; }
.card p { color: var(--text-muted); }

/* Pricing Table */
.pricing-table { display: flex; flex-direction: column; gap: 30px; }
@media (min-width: 768px) { .pricing-table { flex-direction: row; justify-content: center; align-items: stretch; } }
.price-card { flex: 1; max-width: 380px; background: #fff; padding: 50px 30px; border-radius: 16px; border: 1px solid var(--border); text-align: center; position: relative; box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05); transition: transform 0.3s; }
.price-card:hover { transform: translateY(-5px); }
.price-card.popular { border: 2px solid var(--primary); transform: scale(1.03); }
.price-card.popular:hover { transform: scale(1.03) translateY(-5px); }
@media (max-width: 767px) { .price-card.popular { transform: none; } .price-card.popular:hover { transform: translateY(-5px); } }
.badge { position: absolute; top: -15px; left: 50%; transform: translateX(-50%); background: var(--primary); color: #fff; padding: 5px 15px; border-radius: 20px; font-size: 0.85rem; font-weight: bold; }
.price-card h3 { font-size: 1.5rem; margin-bottom: 20px; }
.price-card .price { font-size: 3rem; font-weight: 800; color: var(--text-main); margin-bottom: 5px; }
.price-card .price-desc { font-size: 0.9rem; color: var(--text-muted); margin-bottom: 30px; display: block; }
.price-card ul { list-style: none; margin-bottom: 40px; text-align: left; }
.price-card ul li { margin-bottom: 15px; color: var(--text-muted); display: flex; align-items: center; }
.price-card ul li::before { content: "✓"; color: var(--primary); font-weight: bold; margin-right: 10px; }

/* Blog / SEO Cards */
.blog-card { background: #fff; border-radius: 12px; overflow: hidden; box-shadow: 0 4px 6px rgba(0,0,0,0.05); border: 1px solid var(--border); transition: transform 0.3s; display: flex; flex-direction: column; }
.blog-card:hover { transform: translateY(-5px); }
.blog-card img { width: 100%; height: 200px; object-fit: cover; }
.blog-content { padding: 25px; display: flex; flex-direction: column; flex-grow: 1; }
.blog-content h3 { font-size: 1.15rem; margin-bottom: 12px; line-height: 1.4; }
.blog-content h3 a { color: var(--text-main); transition: color 0.2s; }
.blog-content h3 a:hover { color: var(--primary); }
.blog-content p { font-size: 0.9rem; color: var(--text-muted); margin-bottom: 20px; flex-grow: 1; }
.read-more { font-weight: bold; color: var(--primary); font-size: 0.9rem; display: inline-block; }

/* FAQ */
.faq-item { background: #fff; margin-bottom: 20px; padding: 25px; border-radius: 12px; border: 1px solid var(--border); }
.faq-item h4 { font-size: 1.2rem; margin-bottom: 15px; }

/* Footer */
footer { background: #111827; color: #9CA3AF; text-align: center; padding: 60px 20px; }
.footer-links { display: flex; justify-content: center; gap: 30px; margin-bottom: 30px; flex-wrap: wrap; }
.footer-links a:hover { color: #fff; }

/* Subpages Content */
.page-content { max-width: 800px; margin: 120px auto 60px; padding: 40px; background: #fff; border-radius: 16px; border: 1px solid var(--border); min-height: 60vh; }
.page-content h1 { font-size: 2.2rem; margin-bottom: 30px; }
.page-content h2 { font-size: 1.5rem; margin: 40px 0 20px; }
.page-content p { margin-bottom: 20px; color: var(--text-muted); }
.page-content ul { margin-left: 20px; margin-bottom: 20px; color: var(--text-muted); }
.page-content li { margin-bottom: 10px; }
/* Article links override */
.page-content a { color: var(--primary); text-decoration: underline; }
.page-content a:hover { color: var(--primary-hover); }

/* 返回主页按钮 */
.nav-right { display: flex; align-items: center; margin-left: auto; }
.btn-return {
    display: inline-block;
    padding: 8px 16px;
    background-color: var(--primary);
    color: white !important;
    border-radius: 6px;
    font-size: 0.9rem;
    font-weight: bold;
    transition: background 0.3s, transform 0.2s;
    text-decoration: none;
}
.btn-return:hover {
    background-color: var(--primary-hover);
    transform: translateY(-1px);
}

/* 5卡片 Pricing Grid */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 20px;
  margin-bottom: 40px;
}
@media (min-width: 1024px) {
  .pricing-grid { grid-template-columns: repeat(5, 1fr); }
}
.pricing-grid .price-card {
  padding: 40px 20px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}
.pricing-grid .price-card h3 {
  font-size: 1.3rem;
  margin-bottom: 15px;
}
.pricing-grid .price-card .price {
  font-size: 2.2rem;
  font-weight: 800;
  color: #6366F1;
  margin-bottom: 5px;
}
.pricing-grid .price-card .price span {
  font-size: 1rem;
  color: var(--text-muted);
}
.pricing-grid .price-card .price-desc {
  font-size: 0.95rem;
  color: var(--text-muted);
  margin-bottom: 25px;
}
.pricing-notes {
  margin-top: 40px;
  display: flex;
  flex-direction: column;
  gap: 20px;
  max-width: 1000px;
  margin-left: auto;
  margin-right: auto;
}
.note-box {
  padding: 25px;
  border-radius: 12px;
  text-align: left;
}
.recommend-box {
  background-color: #ECFDF5;
  border: 1px solid #10B981;
  color: #065F46;
}
.alert-box {
  background-color: #FFFBEB;
  border: 1px solid #F59E0B;
  color: #92400E;
}
.note-box h4 {
  margin-bottom: 15px;
  font-size: 1.2rem;
  font-weight: bold;
}
.note-box ul {
  list-style: none;
  margin-left: 0;
}
.note-box ul li {
  margin-bottom: 10px;
  font-size: 1rem;
  display: flex;
  align-items: flex-start;
}
.note-box ul li::before {
  content: "•";
  margin-right: 10px;
  font-weight: bold;
}

.faq-item h3.h4-styled, .card h3.h4-styled { margin-bottom: 15px; font-size: 1.1rem; font-weight: bold; }