/* ==========================================================================
   尔湾云 (Ervanyun) - 纯 CSS 原生样式表 (浅色高质感模式)
   极其轻量，极速加载，响应式设计
   ========================================================================== */

:root {
  --bg-light: #f8fafc;
  --bg-card: #ffffff;
  --bg-card-hover: #ffffff;
  --bg-subtle: #f1f5f9;
  
  --border-color: #e2e8f0;
  --border-accent: rgba(2, 132, 199, 0.4);
  
  --primary: #0284c7;
  --primary-gradient: linear-gradient(135deg, #0284c7 0%, #2563eb 100%);
  --primary-glow: rgba(2, 132, 199, 0.25);
  --secondary: #2563eb;
  --accent-purple: #7c3aed;
  --accent-green: #10b981;
  --accent-orange: #f59e0b;
  
  --text-main: #0f172a;
  --text-heading: #0f172a;
  --text-muted: #475569;
  --text-dim: #64748b;
  
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 24px;
  --radius-pill: 9999px;
  
  --shadow-sm: 0 2px 8px rgba(15, 23, 42, 0.04);
  --shadow-md: 0 8px 24px rgba(15, 23, 42, 0.06);
  --shadow-lg: 0 16px 36px rgba(15, 23, 42, 0.1);
}

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

html {
  font-family: var(--font-sans);
  background-color: var(--bg-light);
  color: var(--text-main);
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
}

body {
  overflow-x: hidden;
  line-height: 1.6;
}

a {
  color: inherit;
  text-decoration: none;
}

/* 布局容器 */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* 导航栏 */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-color);
  padding: 16px 0;
  box-shadow: var(--shadow-sm);
}

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

.logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 22px;
  font-weight: 800;
  letter-spacing: 0.5px;
  color: var(--text-heading);
}

.logo-icon {
  width: 38px;
  height: 38px;
  background: var(--primary-gradient);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 900;
  color: #fff;
  box-shadow: 0 4px 12px var(--primary-glow);
}

.logo-tag {
  font-size: 11px;
  padding: 3px 8px;
  background: rgba(2, 132, 199, 0.08);
  color: var(--primary);
  border: 1px solid rgba(2, 132, 199, 0.2);
  border-radius: var(--radius-pill);
  font-weight: 600;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
  list-style: none;
}

.nav-links a {
  color: var(--text-muted);
  font-weight: 500;
  font-size: 15px;
  transition: var(--transition-fast);
}

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

/* 按钮基础样式 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 28px;
  font-size: 15px;
  font-weight: 600;
  border-radius: var(--radius-pill);
  transition: var(--transition-normal);
  cursor: pointer;
  border: none;
  white-space: nowrap;
}

.btn-primary {
  background: var(--primary-gradient);
  color: #ffffff;
  box-shadow: 0 4px 16px var(--primary-glow);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(2, 132, 199, 0.4);
  filter: brightness(1.05);
}

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

.btn-secondary:hover {
  background: var(--bg-subtle);
  border-color: rgba(2, 132, 199, 0.3);
  color: var(--primary);
  transform: translateY(-2px);
}

.btn-lg {
  padding: 16px 36px;
  font-size: 17px;
}

/* HERO 主视觉区 */
.hero {
  padding: 80px 0 60px;
  text-align: center;
  position: relative;
  background: radial-gradient(circle at 50% 20%, rgba(2, 132, 199, 0.08) 0%, transparent 60%);
}

.hero-glow {
  position: absolute;
  top: 20%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 600px;
  height: 350px;
  background: radial-gradient(circle, rgba(2, 132, 199, 0.12) 0%, rgba(124, 58, 237, 0.06) 50%, transparent 70%);
  filter: blur(60px);
  pointer-events: none;
  z-index: -1;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-pill);
  font-size: 13px;
  color: var(--primary);
  margin-bottom: 24px;
  box-shadow: var(--shadow-sm);
}

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

.hero-title {
  font-size: 54px;
  font-weight: 800;
  line-height: 1.15;
  margin-bottom: 20px;
  color: var(--text-heading);
}

.hero-title .gradient-text {
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 50%, var(--accent-purple) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-subtitle {
  font-size: 19px;
  color: var(--text-muted);
  max-width: 760px;
  margin: 0 auto 36px;
  font-weight: 400;
  line-height: 1.6;
}

.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin-bottom: 40px;
}

/* 首页 AI 科技美图精细渲染框 */
.hero-image-box {
  position: relative;
  margin: 36px auto 40px;
  max-width: 1000px;
  border-radius: var(--radius-lg);
  padding: 8px;
  background: linear-gradient(135deg, rgba(2, 132, 199, 0.3), rgba(124, 58, 237, 0.2));
  box-shadow: 0 20px 50px rgba(2, 132, 199, 0.15);
  transition: var(--transition-normal);
}

.hero-image-box:hover {
  transform: translateY(-4px);
  box-shadow: 0 28px 60px rgba(2, 132, 199, 0.25);
}

.hero-image-box img {
  width: 100%;
  height: auto;
  display: block;
  border-radius: var(--radius-md);
  border: 1px solid rgba(255, 255, 255, 0.8);
}

.hero-stats {
  display: flex;
  justify-content: center;
  gap: 48px;
  padding-top: 30px;
  border-top: 1px solid var(--border-color);
}

.stat-item {
  text-align: center;
}

.stat-num {
  font-size: 28px;
  font-weight: 800;
  color: var(--text-heading);
}

.stat-label {
  font-size: 13px;
  color: var(--text-dim);
  margin-top: 4px;
}

/* 通用章节标题 */
.section {
  padding: 80px 0;
  border-bottom: 1px solid var(--border-color);
}

.section-title-wrap {
  text-align: center;
  max-width: 680px;
  margin: 0 auto 56px;
}

.section-tag {
  font-size: 13px;
  font-weight: 700;
  color: var(--primary);
  text-transform: uppercase;
  letter-spacing: 1.5px;
  margin-bottom: 10px;
  display: block;
}

.section-title {
  font-size: 36px;
  font-weight: 800;
  color: var(--text-heading);
  margin-bottom: 14px;
}

.section-desc {
  font-size: 16px;
  color: var(--text-muted);
}

/* 卡片与网格布局 */
.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 32px 24px;
  transition: var(--transition-normal);
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.feature-card:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-accent);
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.feature-icon {
  width: 50px;
  height: 50px;
  border-radius: var(--radius-sm);
  background: rgba(2, 132, 199, 0.08);
  border: 1px solid rgba(2, 132, 199, 0.15);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  margin-bottom: 20px;
  color: var(--primary);
}

.feature-card h3 {
  font-size: 20px;
  font-weight: 700;
  color: var(--text-heading);
  margin-bottom: 10px;
}

.feature-card p {
  font-size: 14px;
  color: var(--text-muted);
  line-height: 1.6;
}

/* 流媒体与 AI 支持专区 (固定 4x4 矩阵排列) */
.tech-badges-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}

.tech-item {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 16px 20px;
  display: flex;
  align-items: center;
  gap: 12px;
  transition: var(--transition-fast);
  box-shadow: var(--shadow-sm);
}

.tech-item:hover {
  background: #ffffff;
  border-color: rgba(2, 132, 199, 0.3);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.tech-icon-box {
  width: 36px;
  height: 36px;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 13px;
  flex-shrink: 0;
}

.tech-icon-net { background: #E50914; color: #fff; }
.tech-icon-gpt { background: #10a37f; color: #fff; }
.tech-icon-yt { background: #FF0000; color: #fff; }
.tech-icon-claude { background: #d97706; color: #fff; }
.tech-icon-disney { background: #113ccf; color: #fff; }
.tech-icon-mj { background: #2563eb; color: #fff; }
.tech-icon-steam { background: #171a21; color: #66c0f4; }
.tech-icon-sora { background: #7c3aed; color: #fff; }
.tech-icon-copilot { background: #24292e; color: #fff; }
.tech-icon-hbo { background: #5822b4; color: #fff; }
.tech-icon-spotify { background: #1ed760; color: #000; }
.tech-icon-prime { background: #00a8e1; color: #fff; }
.tech-icon-ppx { background: #22b8cf; color: #fff; }
.tech-icon-tiktok { background: #000000; color: #25f4ee; }
.tech-icon-twitch { background: #9146ff; color: #fff; }
.tech-icon-epic { background: #313131; color: #fff; }

.tech-info h4 {
  font-size: 15px;
  color: var(--text-heading);
  font-weight: 600;
}

.tech-info span {
  font-size: 12px;
  color: var(--text-dim);
}

/* 价格套餐表 */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  align-items: stretch;
}

.pricing-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 36px 28px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: var(--transition-normal);
  box-shadow: var(--shadow-sm);
}

.pricing-card:hover {
  border-color: var(--primary);
  box-shadow: var(--shadow-lg);
}

.pricing-card.popular {
  background: #ffffff;
  border: 2px solid var(--primary);
  box-shadow: 0 12px 32px rgba(2, 132, 199, 0.15);
}

.popular-badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--primary-gradient);
  color: #ffffff;
  padding: 4px 18px;
  border-radius: var(--radius-pill);
  font-size: 12px;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  box-shadow: 0 4px 10px rgba(2, 132, 199, 0.3);
}

.pricing-plan-name {
  font-size: 22px;
  font-weight: 700;
  color: var(--text-heading);
  margin-bottom: 6px;
}

.pricing-plan-desc {
  font-size: 13px;
  color: var(--text-dim);
  margin-bottom: 24px;
}

.pricing-price {
  font-size: 42px;
  font-weight: 900;
  color: var(--text-heading);
  margin-bottom: 24px;
  display: flex;
  align-items: baseline;
  gap: 4px;
}

.pricing-price .currency {
  font-size: 24px;
  color: var(--primary);
}

.pricing-price .period {
  font-size: 14px;
  color: var(--text-dim);
  font-weight: 400;
}

.pricing-features {
  list-style: none;
  margin-bottom: 32px;
  flex-grow: 1;
}

.pricing-features li {
  padding: 10px 0;
  border-bottom: 1px dashed var(--border-color);
  font-size: 14px;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 10px;
}

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

.pricing-features li.disabled {
  color: var(--text-dim);
  text-decoration: line-through;
}

.pricing-features li.disabled::before {
  content: "✕";
  color: var(--text-dim);
}

/* 用户评价 */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.review-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 28px;
  box-shadow: var(--shadow-sm);
}

.review-rating {
  color: var(--accent-orange);
  font-size: 16px;
  margin-bottom: 12px;
}

.review-text {
  font-size: 14px;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 20px;
  font-style: italic;
}

.review-author {
  display: flex;
  align-items: center;
  gap: 12px;
}

.avatar-circle {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--primary-gradient);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  color: #fff;
  font-size: 14px;
}

.author-info h4 {
  font-size: 14px;
  color: var(--text-heading);
  font-weight: 600;
}

.author-info span {
  font-size: 12px;
  color: var(--text-dim);
}

/* FAQ 常见问题 */
.faq-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.faq-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 24px 28px;
  box-shadow: var(--shadow-sm);
}

.faq-card h3 {
  font-size: 17px;
  color: var(--text-heading);
  font-weight: 700;
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.faq-card h3::before {
  content: "Q";
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 24px;
  background: rgba(2, 132, 199, 0.1);
  color: var(--primary);
  border-radius: 50%;
  font-size: 12px;
  font-weight: 800;
}

.faq-card p {
  font-size: 14px;
  color: var(--text-muted);
  line-height: 1.6;
  padding-left: 34px;
}

/* 页脚 (根据要求：页脚只保留四个标题，点击在新窗口打开) */
.footer {
  background: #ffffff;
  padding: 48px 0;
  border-top: 1px solid var(--border-color);
  text-align: center;
}

.footer-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 48px;
  margin-bottom: 24px;
  list-style: none;
}

.footer-nav a {
  font-size: 16px;
  font-weight: 600;
  color: var(--text-muted);
  transition: var(--transition-fast);
  padding: 6px 12px;
  border-radius: var(--radius-sm);
}

.footer-nav a:hover {
  color: var(--primary);
  background: var(--bg-subtle);
}

.footer-copy {
  font-size: 13px;
  color: var(--text-dim);
}

/* 独立子页面内容通用样式 */
.subpage-header {
  padding: 60px 0 30px;
  border-bottom: 1px solid var(--border-color);
  margin-bottom: 40px;
  background: #ffffff;
}

.subpage-title {
  font-size: 38px;
  font-weight: 800;
  color: var(--text-heading);
  margin-bottom: 12px;
}

.subpage-subtitle {
  font-size: 15px;
  color: var(--text-muted);
}

.subpage-body {
  padding-bottom: 80px;
}

.content-block {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 36px;
  margin-bottom: 30px;
  box-shadow: var(--shadow-sm);
}

.content-block h2 {
  font-size: 22px;
  color: var(--primary);
  font-weight: 700;
  margin-bottom: 16px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border-color);
}

.content-block h3 {
  font-size: 17px;
  color: var(--text-heading);
  margin: 18px 0 10px;
}

.content-block p {
  font-size: 15px;
  color: var(--text-muted);
  line-height: 1.8;
  margin-bottom: 14px;
}

.content-block ul {
  padding-left: 20px;
  margin-bottom: 14px;
  color: var(--text-muted);
}

.content-block li {
  margin-bottom: 8px;
  font-size: 14px;
}

/* 网站地图样式 */
.sitemap-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.sitemap-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 28px;
  box-shadow: var(--shadow-sm);
}

.sitemap-card h3 {
  font-size: 18px;
  color: var(--primary);
  margin-bottom: 16px;
}

.sitemap-list {
  list-style: none;
}

.sitemap-list li {
  padding: 8px 0;
  border-bottom: 1px solid var(--border-color);
}

.sitemap-list a {
  color: var(--text-muted);
  font-size: 15px;
  transition: var(--transition-fast);
}

.sitemap-list a:hover {
  color: var(--primary);
  padding-left: 6px;
}

/* ==========================================================================
   响应式媒体查询 (@media) - 手机端完美适配
   ========================================================================== */
@media (max-width: 992px) {
  .hero-title { font-size: 42px; }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .tech-badges-grid { grid-template-columns: repeat(2, 1fr); }
  .pricing-grid { grid-template-columns: 1fr; max-width: 480px; margin: 0 auto; }
  .reviews-grid { grid-template-columns: 1fr; }
  .sitemap-grid { grid-template-columns: 1fr; }
}

@media (max-width: 768px) {
  .header-inner {
    flex-direction: row;
  }
  
  .nav-links {
    display: none; /* 移动端保持简洁 */
  }

  .hero {
    padding: 60px 0 40px;
  }

  .hero-title {
    font-size: 32px;
  }

  .hero-subtitle {
    font-size: 15px;
  }

  .hero-actions {
    flex-direction: column;
    width: 100%;
    gap: 12px;
  }

  .btn {
    width: 100%;
    min-height: 48px; /* 适合手指触摸点击 */
  }

  .hero-stats {
    flex-direction: row;
    flex-wrap: wrap;
    gap: 20px;
  }

  .stat-item {
    flex: 1 1 40%;
  }

  .section {
    padding: 50px 0;
  }

  .section-title {
    font-size: 26px;
  }

  .grid-3, .grid-4, .grid-2, .faq-grid {
    grid-template-columns: 1fr;
  }

  .tech-badges-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .footer-nav {
    flex-direction: column;
    gap: 16px;
  }
  
  .content-block {
    padding: 24px;
  }
}