:root {
  --brand-purple: #7C3AED;
  --brand-purple-light: #F5F3FF;
  --brand-purple-dark: #5B21B6;
  --bg-color: #F9FAFB;
  --surface: #FFFFFF;
  --text-main: #111827;
  --text-secondary: #4B5563;
  --text-muted: #9CA3AF;
  --border-color: #E5E7EB;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-pill: 999px;
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
body { font-family: var(--font-family); background-color: var(--bg-color); color: var(--text-main); line-height: 1.6; -webkit-font-smoothing: antialiased; }
a { text-decoration: none; color: inherit; }
ul { list-style: none; }
img { display: block; max-width: 100%; }

/* 导航 */
header { position: sticky; top: 0; z-index: 100; background: rgba(255,255,255,0.9); backdrop-filter: blur(10px); border-bottom: 1px solid var(--border-color); }
.nav-container { max-width: 1200px; margin: 0 auto; padding: 0 20px; height: 64px; display: flex; align-items: center; justify-content: space-between; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 18px; color: var(--text-main); }
.brand img { height: 32px; width: auto; border-radius: 4px; }
.nav-links { display: flex; gap: 24px; align-items: center; }
.nav-links a { font-size: 14px; color: var(--text-secondary); transition: color 0.2s; }
.nav-links a:hover { color: var(--brand-purple); }
.btn-nav-download { background: var(--brand-purple); color: #fff; padding: 8px 16px; border-radius: var(--radius-pill); font-size: 14px; font-weight: 500; border: none; cursor: pointer; transition: background 0.2s; }
.btn-nav-download:hover { background: var(--brand-purple-dark); }

/* 首屏 */
.hero { max-width: 1200px; margin: 0 auto; padding: 60px 20px; display: grid; grid-template-columns: 1fr 1fr; gap: 40px; align-items: center; }
.hero-content h1 { font-size: 42px; line-height: 1.2; font-weight: 800; margin-bottom: 20px; color: var(--text-main); }
.hero-content h1 span { color: var(--brand-purple); }
.hero-desc { font-size: 16px; color: var(--text-secondary); margin-bottom: 32px; max-width: 480px; }
.data-dashboard { display: flex; gap: 32px; margin-bottom: 40px; padding: 20px 0; border-top: 1px solid var(--border-color); border-bottom: 1px solid var(--border-color); }
.data-item { display: flex; flex-direction: column; }
.data-num { font-size: 28px; font-weight: 800; color: var(--brand-purple); line-height: 1.1; }
.data-label { font-size: 13px; color: var(--text-muted); margin-top: 4px; }
.hero-actions { display: flex; gap: 16px; flex-wrap: wrap; }
.btn-primary { background: var(--brand-purple); color: #fff; padding: 14px 32px; border-radius: var(--radius-pill); font-size: 16px; font-weight: 600; border: none; cursor: pointer; transition: all 0.2s; display: inline-flex; align-items: center; justify-content: center; }
.btn-primary:hover { background: var(--brand-purple-dark); transform: translateY(-2px); }
.btn-outline { background: transparent; color: var(--brand-purple); padding: 14px 32px; border-radius: var(--radius-pill); font-size: 16px; font-weight: 600; border: 1px solid var(--brand-purple); cursor: pointer; transition: all 0.2s; display: inline-flex; align-items: center; justify-content: center; }
.btn-outline:hover { background: var(--brand-purple-light); transform: translateY(-2px); }

/* 轮播 */
.hero-carousel { position: relative; overflow: hidden; border-radius: var(--radius-lg); background: var(--surface); box-shadow: 0 10px 30px rgba(0,0,0,0.05); aspect-ratio: 3/4; max-width: 400px; margin-left: auto; width: 100%; border: 1px solid var(--border-color); }
.carousel-track { display: flex; transition: transform 0.5s ease; height: 100%; }
.carousel-slide { min-width: 100%; height: 100%; position: relative; }
.carousel-slide img { width: 100%; height: 100%; object-fit: cover; }
.carousel-indicators { position: absolute; bottom: 16px; left: 50%; transform: translateX(-50%); display: flex; gap: 8px; }
.indicator { width: 8px; height: 8px; border-radius: 50%; background: rgba(255,255,255,0.5); cursor: pointer; transition: all 0.3s; border: none; padding: 0; }
.indicator.active { background: #fff; width: 20px; border-radius: 4px; }

/* 通用区块 */
.section { max-width: 1200px; margin: 0 auto; padding: 80px 20px; }
.section-header { text-align: center; margin-bottom: 48px; }
.section-header h2 { font-size: 32px; font-weight: 700; color: var(--text-main); margin-bottom: 12px; }
.section-header p { font-size: 15px; color: var(--text-secondary); max-width: 600px; margin: 0 auto; }

/* 海量书库 */
.category-tags { display: flex; flex-wrap: wrap; gap: 10px; justify-content: center; margin-bottom: 40px; }
.tag-pill { background: var(--surface); border: 1px solid var(--border-color); color: var(--text-secondary); padding: 6px 16px; border-radius: var(--radius-pill); font-size: 14px; cursor: pointer; transition: all 0.2s; }
.tag-pill:hover, .tag-pill.active { background: var(--brand-purple-light); border-color: var(--brand-purple); color: var(--brand-purple); font-weight: 500; }
.grid-wall { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.book-card { background: var(--surface); border-radius: var(--radius-md); overflow: hidden; border: 1px solid var(--border-color); transition: transform 0.2s; display: flex; flex-direction: column; }
.book-card:hover { transform: translateY(-4px); box-shadow: 0 8px 20px rgba(0,0,0,0.06); }
.book-cover { width: 100%; aspect-ratio: 3/4; object-fit: cover; background: var(--bg-color); }
.book-info { padding: 12px; flex-grow: 1; display: flex; flex-direction: column; justify-content: space-between; }
.book-title { font-size: 14px; font-weight: 600; color: var(--text-main); margin-bottom: 4px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.book-chapter { font-size: 12px; color: var(--text-muted); }

/* 智能阅读 */
.tri-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.feature-box { background: var(--surface); border: 1px solid var(--border-color); border-radius: var(--radius-lg); padding: 32px 24px; text-align: center; transition: border-color 0.2s; }
.feature-box:hover { border-color: var(--brand-purple); }
.feature-icon { width: 48px; height: 48px; margin: 0 auto 16px; background: var(--brand-purple-light); color: var(--brand-purple); border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 24px; font-weight: 700; }
.feature-box h3 { font-size: 18px; font-weight: 600; margin-bottom: 10px; }
.feature-box p { font-size: 14px; color: var(--text-secondary); line-height: 1.5; }

/* 4K超清 */
.split-console { display: grid; grid-template-columns: 1fr 1fr; gap: 0; border-radius: var(--radius-lg); overflow: hidden; border: 1px solid var(--border-color); background: var(--surface); position: relative; max-width: 900px; margin: 0 auto; }
.console-panel { padding: 40px 24px; display: flex; flex-direction: column; align-items: center; justify-content: center; text-align: center; }
.console-panel.left { border-right: 1px solid var(--border-color); background: #F3F4F6; }
.console-panel.right { background: var(--brand-purple-light); }
.console-panel h3 { font-size: 20px; font-weight: 600; margin-bottom: 8px; }
.console-panel p { font-size: 14px; color: var(--text-secondary); }
.console-visual { width: 100%; height: 180px; border-radius: var(--radius-sm); margin-bottom: 20px; display: flex; align-items: center; justify-content: center; font-size: 13px; color: var(--text-muted); border: 1px dashed var(--border-color); position: relative; overflow: hidden; }
.console-visual img { width: 100%; height: 100%; object-fit: cover; opacity: 0.6; }
.console-panel.right .console-visual img { opacity: 1; }
.console-panel.right .console-visual { border: 2px solid var(--brand-purple); }
.console-divider { position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%); width: 4px; height: 80%; background: var(--brand-purple); border-radius: 2px; z-index: 10; box-shadow: 0 0 10px rgba(124,58,237,0.4); }
.console-divider::after { content: ''; position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%); width: 16px; height: 16px; background: var(--brand-purple); border: 3px solid #fff; border-radius: 50%; }

/* 同好社区 */
.data-stream { max-width: 800px; margin: 0 auto; display: flex; flex-direction: column; gap: 12px; }
.stream-card { background: var(--surface); border: 1px solid var(--border-color); border-radius: var(--radius-md); padding: 16px 20px; display: flex; align-items: center; gap: 16px; transition: border-color 0.2s; }
.stream-card:hover { border-color: var(--brand-purple); }
.user-avatar { width: 40px; height: 40px; border-radius: 50%; object-fit: cover; border: 1px solid var(--border-color); }
.user-info { flex: 1; }
.user-name { font-size: 15px; font-weight: 600; color: var(--text-main); }
.user-tags { display: flex; gap: 8px; margin-top: 4px; }
.user-tag { font-size: 11px; color: var(--text-secondary); background: var(--bg-color); padding: 2px 8px; border-radius: 4px; border: 1px solid var(--border-color); }
.match-rate { width: 120px; text-align: right; }
.match-rate span { font-size: 13px; font-weight: 600; color: var(--brand-purple); }
.progress-bar-bg { width: 100%; height: 6px; background: var(--border-color); border-radius: 3px; margin-top: 6px; overflow: hidden; }
.progress-bar-fill { height: 100%; background: var(--brand-purple); border-radius: 3px; }

/* 创作互动 */
.task-panel { display: grid; grid-template-columns: 1fr 1fr; gap: 32px; }
.panel-card { background: var(--surface); border: 1px solid var(--border-color); border-radius: var(--radius-lg); padding: 24px; }
.panel-card h3 { font-size: 18px; font-weight: 600; margin-bottom: 20px; border-bottom: 1px solid var(--border-color); padding-bottom: 12px; }
.vote-item { margin-bottom: 16px; }
.vote-info { display: flex; justify-content: space-between; font-size: 14px; margin-bottom: 6px; color: var(--text-secondary); }
.vote-bar-bg { width: 100%; height: 8px; background: var(--bg-color); border-radius: 4px; overflow: hidden; }
.vote-bar-fill { height: 100%; background: var(--brand-purple); border-radius: 4px; }
.creation-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.creation-item { position: relative; border-radius: var(--radius-sm); overflow: hidden; aspect-ratio: 1/1; }
.creation-item img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.3s; }
.creation-item:hover img { transform: scale(1.05); }
.creation-likes { position: absolute; bottom: 8px; right: 8px; background: rgba(0,0,0,0.6); color: #fff; padding: 2px 8px; border-radius: var(--radius-pill); font-size: 12px; display: flex; align-items: center; gap: 4px; }

/* 常见问题 */
.faq-grid { display: grid; grid-template-columns: 200px 1fr; gap: 40px; max-width: 900px; margin: 0 auto; }
.faq-categories { display: flex; flex-direction: column; gap: 8px; }
.faq-cat { padding: 10px 16px; border-radius: var(--radius-sm); cursor: pointer; font-size: 14px; color: var(--text-secondary); border: 1px solid transparent; transition: all 0.2s; }
.faq-cat.active, .faq-cat:hover { background: var(--brand-purple-light); color: var(--brand-purple); border-color: var(--brand-purple); font-weight: 500; }
.faq-list { display: flex; flex-direction: column; gap: 12px; }
.accordion-item { border: 1px solid var(--border-color); border-radius: var(--radius-md); background: var(--surface); overflow: hidden; }
.accordion-header { padding: 16px 20px; cursor: pointer; display: flex; justify-content: space-between; align-items: center; font-weight: 500; font-size: 15px; }
.accordion-header:hover { background: var(--bg-color); }
.accordion-icon { transition: transform 0.3s; color: var(--brand-purple); }
.accordion-item.open .accordion-icon { transform: rotate(180deg); }
.accordion-body { max-height: 0; overflow: hidden; transition: max-height 0.3s ease; padding: 0 20px; font-size: 14px; color: var(--text-secondary); }
.accordion-item.open .accordion-body { padding-bottom: 16px; }

/* 下载区 */
.download-section { background: var(--brand-purple-light); padding: 80px 20px; border-top: 1px solid var(--border-color); border-bottom: 1px solid var(--border-color); }
.download-content { max-width: 900px; margin: 0 auto; text-align: center; }
.download-content h2 { font-size: 32px; font-weight: 700; margin-bottom: 16px; }
.download-content p { font-size: 15px; color: var(--text-secondary); margin-bottom: 32px; max-width: 600px; margin-left: auto; margin-right: auto; }
.steps-list { display: flex; justify-content: center; gap: 24px; margin-bottom: 40px; flex-wrap: wrap; }
.step-item { display: flex; align-items: center; gap: 8px; font-size: 14px; color: var(--text-secondary); background: var(--surface); padding: 8px 16px; border-radius: var(--radius-pill); border: 1px solid var(--border-color); }
.step-num { width: 22px; height: 22px; background: var(--brand-purple); color: #fff; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 12px; font-weight: 600; }
.download-buttons { display: flex; justify-content: center; gap: 16px; flex-wrap: wrap; }
.btn-download { background: var(--brand-purple); color: #fff; padding: 16px 40px; border-radius: var(--radius-pill); font-size: 16px; font-weight: 600; border: none; cursor: pointer; transition: all 0.2s; display: inline-flex; align-items: center; justify-content: center; gap: 8px; min-width: 200px; }
.btn-download:hover { background: var(--brand-purple-dark); transform: translateY(-2px); box-shadow: 0 4px 12px rgba(124,58,237,0.3); }
.btn-download.secondary { background: var(--surface); color: var(--brand-purple); border: 1px solid var(--brand-purple); }
.btn-download.secondary:hover { background: var(--brand-purple-light); }

/* 页脚 */
footer { background: var(--surface); padding: 40px 20px; border-top: 1px solid var(--border-color); }
.footer-container { max-width: 1200px; margin: 0 auto; display: flex; flex-direction: column; gap: 24px; }
.footer-top { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 16px; }
.footer-brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 16px; }
.footer-brand img { height: 28px; width: auto; }
.footer-links { display: flex; gap: 24px; }
.footer-links a { font-size: 14px; color: var(--text-secondary); }
.footer-links a:hover { color: var(--brand-purple); }
.footer-bottom { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 12px; border-top: 1px solid var(--border-color); padding-top: 24px; font-size: 13px; color: var(--text-muted); }
.footer-bottom time { font-size: 12px; color: var(--text-muted); }

/* 模态框 */
.modal-overlay { position: fixed; inset: 0; background: rgba(0,0,0,0.5); display: none; align-items: center; justify-content: center; z-index: 1000; padding: 20px; }
.modal-overlay.active { display: flex; }
.modal-content { background: var(--surface); border-radius: var(--radius-lg); padding: 24px; max-width: 400px; width: 100%; text-align: center; }
.modal-content p { font-size: 15px; color: var(--text-secondary); margin-bottom: 16px; line-height: 1.5; }
.modal-link-box { background: var(--bg-color); border: 1px solid var(--border-color); padding: 12px; border-radius: var(--radius-sm); font-size: 13px; color: var(--text-main); word-break: break-all; margin-bottom: 16px; text-align: left; }
.btn-copy { background: var(--brand-purple); color: #fff; padding: 12px 24px; border-radius: var(--radius-pill); border: none; font-size: 15px; font-weight: 600; cursor: pointer; width: 100%; margin-bottom: 12px; }
.btn-copy:hover { background: var(--brand-purple-dark); }
.btn-close { background: transparent; border: none; color: var(--text-muted); font-size: 14px; cursor: pointer; padding: 8px; }

/* 响应式 */
@media (max-width: 1024px) {
  .hero { grid-template-columns: 1fr; gap: 40px; text-align: center; }
  .hero-content h1 { font-size: 36px; }
  .hero-desc { margin: 0 auto 32px; }
  .data-dashboard { justify-content: center; }
  .hero-actions { justify-content: center; }
  .hero-carousel { margin: 0 auto; }
  .grid-wall { grid-template-columns: repeat(3, 1fr); }
  .task-panel { grid-template-columns: 1fr; }
}
@media (max-width: 768px) {
  .nav-links { display: none; }
  .hero-content h1 { font-size: 28px; }
  .data-dashboard { flex-direction: column; gap: 16px; align-items: center; text-align: center; }
  .data-item { align-items: center; }
  .hero-actions { flex-direction: column; width: 100%; }
  .btn-primary, .btn-outline { width: 100%; }
  .grid-wall { grid-template-columns: repeat(2, 1fr); gap: 16px; }
  .tri-grid { grid-template-columns: 1fr; }
  .split-console { grid-template-columns: 1fr; }
  .console-panel.left { border-right: none; border-bottom: 1px solid var(--border-color); }
  .console-divider { display: none; }
  .faq-grid { grid-template-columns: 1fr; gap: 20px; }
  .faq-categories { flex-direction: row; flex-wrap: wrap; justify-content: center; }
  .stream-card { flex-direction: column; align-items: flex-start; gap: 12px; }
  .match-rate { width: 100%; text-align: left; }
  .footer-top { flex-direction: column; align-items: flex-start; }
  .footer-bottom { flex-direction: column; align-items: flex-start; gap: 8px; }
}