/* ==========================================================================
   影子云 (Yingzi Cloud) 官网落地页核心样式表 - yingzi.cfd
   极简白雅调 + 云朵纹理 + 柔和浮雕影子视觉系统
   ========================================================================== */

:root {
  --bg-main: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-card: #ffffff;
  --bg-card-hover: #ffffff;
  --primary: #0284c7;
  --primary-hover: #0369a1;
  --primary-glow: rgba(2, 132, 199, 0.15);
  --secondary: #2563eb;
  --accent-purple: #7c3aed;
  --text-main: #0f172a;
  --text-muted: #475569;
  --text-dim: #94a3b8;
  --border-color: #e2e8f0;
  --border-highlight: #38bdf8;
  
  /* 柔和浮雕影子 (Shadow System) */
  --shadow-sm: 0 2px 4px rgba(15, 23, 42, 0.04);
  --shadow-md: 0 10px 25px -5px rgba(15, 23, 42, 0.08), 0 8px 10px -6px rgba(15, 23, 42, 0.04);
  --shadow-lg: 0 20px 35px -10px rgba(15, 23, 42, 0.12), 0 10px 15px -5px rgba(15, 23, 42, 0.06);
  --shadow-cloud: 0 20px 40px -12px rgba(2, 132, 199, 0.22);
  
  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --font-family: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
}

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

html {
  scroll-behavior: smooth;
  font-family: var(--font-family);
  background-color: var(--bg-main);
  color: var(--text-main);
  line-height: 1.6;
}

body {
  overflow-x: hidden;
  /* 纯白背景搭配淡蓝极光云纹理 */
  background: 
    radial-gradient(circle at 10% 20%, rgba(224, 242, 254, 0.6) 0%, transparent 40%),
    radial-gradient(circle at 90% 60%, rgba(238, 242, 255, 0.7) 0%, transparent 40%),
    linear-gradient(180deg, #f0f9ff 0%, #ffffff 40%, #f8fafc 100%);
  min-height: 100vh;
}

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

/* 导航栏 (白色磨砂玻璃) */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-color);
  padding: 0.9rem 0;
  box-shadow: var(--shadow-sm);
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

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

.brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-weight: 800;
  font-size: 1.4rem;
  letter-spacing: -0.5px;
}

.brand img {
  width: 38px;
  height: 38px;
  object-fit: contain;
  filter: drop-shadow(0 4px 8px rgba(2, 132, 199, 0.25));
}

.brand-text {
  background: linear-gradient(135deg, #0284c7 0%, #2563eb 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 2rem;
  list-style: none;
}

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

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

.nav-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.65rem 1.35rem;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 0.92rem;
  cursor: pointer;
  transition: var(--transition);
  border: none;
  outline: none;
}

.btn-recommend {
  background: #f3e8ff;
  color: #7e22ce;
  border: 1px solid #e9d5ff;
  box-shadow: 0 2px 6px rgba(126, 34, 206, 0.08);
}

.btn-recommend:hover {
  background: #e9d5ff;
  color: #6b21a8;
  box-shadow: 0 4px 12px rgba(126, 34, 206, 0.2);
  transform: translateY(-2px);
}

.btn-primary {
  background: linear-gradient(135deg, #0284c7 0%, #2563eb 100%);
  color: #ffffff;
  box-shadow: 0 4px 14px rgba(2, 132, 199, 0.35);
}

.btn-primary:hover {
  opacity: 0.95;
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(2, 132, 199, 0.45);
}

.btn-outline {
  background: #ffffff;
  color: var(--text-main);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
}

.btn-outline:hover {
  border-color: var(--primary);
  color: var(--primary);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.btn-lg {
  padding: 0.85rem 1.85rem;
  font-size: 1.05rem;
  border-radius: var(--radius-md);
}

/* Hero Section (云朵与影子背景效果) */
.hero {
  padding: 9.5rem 0 5rem;
  position: relative;
  text-align: center;
}

/* 浮动背景云朵与影子 */
.hero::before {
  content: "";
  position: absolute;
  top: 15%;
  left: 8%;
  width: 180px;
  height: 90px;
  background: rgba(255, 255, 255, 0.9);
  border-radius: 100px;
  box-shadow: 0 15px 35px rgba(2, 132, 199, 0.12);
  filter: blur(1px);
  pointer-events: none;
  animation: floatCloud 8s ease-in-out infinite alternate;
}

.hero::after {
  content: "";
  position: absolute;
  top: 25%;
  right: 10%;
  width: 240px;
  height: 110px;
  background: rgba(255, 255, 255, 0.85);
  border-radius: 100px;
  box-shadow: 0 20px 45px rgba(37, 99, 235, 0.15);
  filter: blur(2px);
  pointer-events: none;
  animation: floatCloud 10s ease-in-out infinite alternate-reverse;
}

@keyframes floatCloud {
  0% { transform: translateY(0px) translateX(0px); }
  100% { transform: translateY(-18px) translateX(12px); }
}

.hero-glow {
  position: absolute;
  top: 20%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 650px;
  height: 350px;
  background: radial-gradient(circle, rgba(186, 230, 253, 0.5) 0%, rgba(199, 210, 254, 0.3) 60%, transparent 70%);
  filter: blur(70px);
  pointer-events: none;
  z-index: 0;
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 880px;
  margin: 0 auto;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.45rem 1.1rem;
  background: #ffffff;
  border: 1px solid #bae6fd;
  border-radius: 50px;
  color: var(--primary);
  font-size: 0.88rem;
  font-weight: 700;
  margin-bottom: 1.5rem;
  box-shadow: 0 4px 12px rgba(2, 132, 199, 0.1);
}

.badge-dot {
  width: 8px;
  height: 8px;
  background: var(--primary);
  border-radius: 50%;
  box-shadow: 0 0 8px var(--primary);
}

.hero h1 {
  font-size: 3.2rem;
  font-weight: 800;
  line-height: 1.25;
  margin-bottom: 1.5rem;
  letter-spacing: -1px;
  color: #0f172a;
}

.hero h1 span {
  background: linear-gradient(135deg, #0284c7 0%, #2563eb 50%, #7c3aed 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero p {
  font-size: 1.15rem;
  color: var(--text-muted);
  margin-bottom: 2.5rem;
  line-height: 1.8;
}

.hero-cta {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 1.2rem;
  flex-wrap: wrap;
  margin-bottom: 3.5rem;
}

.features-banner {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1.5rem;
  background: #ffffff;
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-md);
  padding: 2rem;
  border-radius: var(--radius-lg);
  margin-top: 2rem;
  position: relative;
}

.feature-mini-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
}

.feature-mini-item .icon {
  font-size: 2rem;
}

.feature-mini-item h4 {
  font-size: 1.05rem;
  color: var(--text-main);
  font-weight: 700;
}

.feature-mini-item p {
  font-size: 0.88rem;
  color: var(--text-muted);
  margin: 0;
}

/* 通用 Section 样式 */
.section {
  padding: 6rem 0;
  position: relative;
}

.section-header {
  text-align: center;
  max-width: 750px;
  margin: 0 auto 4rem;
}

.section-title {
  font-size: 2.2rem;
  font-weight: 800;
  margin-bottom: 1rem;
  color: #0f172a;
}

.section-subtitle {
  color: var(--text-muted);
  font-size: 1.08rem;
}

/* 核心优势卡片（云朵立体影子） */
.grid-3 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2rem;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  padding: 2.2rem;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  transition: var(--transition);
  position: relative;
}

.card:hover {
  transform: translateY(-6px);
  border-color: var(--border-highlight);
  box-shadow: var(--shadow-cloud);
}

.card-icon {
  width: 54px;
  height: 54px;
  background: #f0f9ff;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.7rem;
  color: var(--primary);
  margin-bottom: 1.5rem;
  border: 1px solid #bae6fd;
  box-shadow: 0 4px 10px rgba(2, 132, 199, 0.12);
}

.card h3 {
  font-size: 1.35rem;
  margin-bottom: 0.8rem;
  color: #0f172a;
}

.card p {
  color: var(--text-muted);
  font-size: 0.96rem;
  line-height: 1.7;
}

/* 套餐价格表 (纯白立体影子卡片) */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 2rem;
}

.pricing-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2.5rem 2rem;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: var(--transition);
  box-shadow: var(--shadow-md);
}

.pricing-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
}

.pricing-card.popular {
  border: 2px solid var(--primary);
  box-shadow: var(--shadow-cloud);
}

.popular-tag {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: linear-gradient(135deg, #0284c7, #2563eb);
  color: #ffffff;
  font-size: 0.8rem;
  font-weight: 700;
  padding: 0.35rem 1.1rem;
  border-radius: 50px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  box-shadow: 0 4px 12px rgba(2, 132, 199, 0.3);
}

.pricing-card h3 {
  font-size: 1.4rem;
  margin-bottom: 0.5rem;
  color: #0f172a;
}

.pricing-card .desc {
  color: var(--text-muted);
  font-size: 0.88rem;
  margin-bottom: 1.5rem;
}

.price {
  font-size: 2.8rem;
  font-weight: 800;
  color: #0f172a;
  margin-bottom: 1.5rem;
  display: flex;
  align-items: baseline;
  gap: 0.3rem;
}

.price span.currency {
  font-size: 1.4rem;
  color: var(--primary);
}

.price span.period {
  font-size: 0.95rem;
  color: var(--text-dim);
  font-weight: 500;
}

.pricing-features {
  list-style: none;
  margin-bottom: 2rem;
  flex-grow: 1;
}

.pricing-features li {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--text-muted);
  font-size: 0.94rem;
  margin-bottom: 0.85rem;
}

.pricing-features li::before {
  content: "✓";
  color: var(--primary);
  font-weight: bold;
}

/* 文章矩阵 */
.article-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: 2rem;
}

.article-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-md);
}

.article-card:hover {
  border-color: var(--border-highlight);
  transform: translateY(-5px);
  box-shadow: var(--shadow-cloud);
}

.article-meta {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin-bottom: 1rem;
}

.tag {
  background: #f0f9ff;
  color: var(--primary);
  font-size: 0.78rem;
  font-weight: 700;
  padding: 0.25rem 0.7rem;
  border-radius: 6px;
  border: 1px solid #bae6fd;
}

.article-card h3 {
  font-size: 1.25rem;
  margin-bottom: 0.8rem;
  line-height: 1.45;
  color: #0f172a;
}

.article-card h3 a:hover {
  color: var(--primary);
}

.article-card p {
  color: var(--text-muted);
  font-size: 0.92rem;
  line-height: 1.65;
  margin-bottom: 1.5rem;
  flex-grow: 1;
}

.article-link {
  color: var(--primary);
  font-weight: 700;
  font-size: 0.92rem;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}

.article-link:hover {
  gap: 0.7rem;
  color: var(--primary-hover);
}

/* 文章详情页样式 (纯白清爽体验) */
.article-page {
  padding-top: 8rem;
  padding-bottom: 6rem;
}

.article-wrapper {
  max-width: 880px;
  margin: 0 auto;
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 3.5rem;
  box-shadow: var(--shadow-lg);
}

.article-header {
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 2rem;
  margin-bottom: 2.5rem;
}

.article-header h1 {
  font-size: 2.2rem;
  font-weight: 800;
  line-height: 1.35;
  margin-bottom: 1.2rem;
  color: #0f172a;
}

.article-body {
  color: #334155;
  font-size: 1.05rem;
  line-height: 1.85;
}

.article-body h2 {
  font-size: 1.6rem;
  color: #0f172a;
  margin: 2.5rem 0 1.2rem 0;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid #f1f5f9;
}

.article-body h3 {
  font-size: 1.28rem;
  color: var(--primary);
  margin: 1.8rem 0 0.8rem 0;
}

.article-body p {
  margin-bottom: 1.4rem;
}

.article-body ul, .article-body ol {
  margin-bottom: 1.5rem;
  padding-left: 1.8rem;
}

.article-body li {
  margin-bottom: 0.6rem;
}

.article-cta-box {
  background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 100%);
  border: 1px solid #bae6fd;
  border-radius: var(--radius-md);
  padding: 2.2rem;
  text-align: center;
  margin: 3rem 0 2rem 0;
  box-shadow: var(--shadow-md);
}

.article-cta-box h3 {
  color: #0f172a;
  font-size: 1.4rem;
  margin-bottom: 0.8rem;
}

.article-cta-box p {
  color: var(--text-muted);
  font-size: 0.98rem;
  margin-bottom: 1.5rem;
}

/* 用户评价 (白色阴影立体卡片) */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2rem;
}

.review-card {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2.2rem;
  box-shadow: var(--shadow-md);
  position: relative;
  transition: var(--transition);
}

.review-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
}

.review-stars {
  color: #f59e0b;
  font-size: 1.2rem;
  margin-bottom: 1rem;
}

.review-text {
  color: var(--text-muted);
  font-size: 0.96rem;
  line-height: 1.75;
  margin-bottom: 1.5rem;
  font-style: italic;
}

.review-user {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.avatar {
  width: 46px;
  height: 46px;
  border-radius: 50%;
  background: linear-gradient(135deg, #0284c7, #7c3aed);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: bold;
  color: #fff;
  font-size: 1.1rem;
  box-shadow: 0 4px 10px rgba(2, 132, 199, 0.25);
}

.user-info h4 {
  font-size: 0.98rem;
  color: var(--text-main);
}

.user-info p {
  font-size: 0.82rem;
  color: var(--text-dim);
}

/* FAQ 手风琴 (纯白高品质阴影) */
.faq-list {
  max-width: 820px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 1.2rem;
}

.faq-item {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

.faq-item:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--border-highlight);
}

.faq-question {
  padding: 1.5rem;
  font-weight: 700;
  font-size: 1.08rem;
  color: #0f172a;
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  user-select: none;
}

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

.faq-toggle {
  font-size: 1.4rem;
  transition: transform 0.3s ease;
  color: var(--primary);
}

.faq-item.active .faq-toggle {
  transform: rotate(45deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease-out;
  background: #f8fafc;
}

.faq-answer p {
  padding: 0 1.5rem 1.5rem 1.5rem;
  color: var(--text-muted);
  font-size: 0.98rem;
  line-height: 1.75;
}

/* 页脚 Footer - 遵从核心任务 2 需求 */
footer {
  background: #ffffff;
  border-top: 1px solid var(--border-color);
  padding: 3.5rem 0 2.5rem;
  text-align: center;
  box-shadow: 0 -4px 20px rgba(0, 0, 0, 0.02);
}

.footer-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1.2rem;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 1.15rem;
  font-weight: 800;
  color: #0f172a;
}

.footer-brand img {
  width: 30px;
  height: 30px;
}

.footer-copyright {
  color: var(--text-muted);
  font-size: 0.88rem;
}

/* 友情链接区 - 权重精准输血管道 */
.friend-links {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1.5rem;
  margin-top: 0.5rem;
  padding-top: 1.2rem;
  border-top: 1px solid #f1f5f9;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.friend-links span {
  opacity: 0.8;
}

.friend-links a {
  color: #475569;
  font-size: 0.85rem;
  font-weight: 600;
  transition: color 0.2s ease;
}

.friend-links a:hover {
  color: var(--primary);
  text-decoration: underline;
}

/* 响应式调整 */
@media (max-width: 768px) {
  .nav-links {
    display: none;
  }
  .hero h1 {
    font-size: 2.2rem;
  }
  .hero p {
    font-size: 1rem;
  }
  .section-title {
    font-size: 1.75rem;
  }
  .article-wrapper {
    padding: 1.8rem;
  }
}