/* ========== 基础重置与变量 ========== */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
:root {
  --tg-blue: #24A1DE;
  --tg-dark: #17212b;
  --tg-darker: #0e1621;
  --tg-card: #ffffff;
  --tg-gray: #f5f7fa;
  --tg-text: #333333;
  --tg-text-light: #666666;
  --tg-border: #e5e7eb;
  --tg-green: #34c759;
  --tg-yellow: #ffcc00;
  --tg-red: #ff3b30;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.10);
  --shadow-lg: 0 10px 40px rgba(0,0,0,0.12);
  --radius: 12px;
  --radius-sm: 8px;
  --max-width: 1200px;
}
html { scroll-behavior: smooth; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--tg-text);
  line-height: 1.7;
  background: #fff;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; display: block; }
a { color: var(--tg-blue); text-decoration: none; }
ul { list-style: none; }
button { cursor: pointer; border: none; background: none; font-family: inherit; }
.container { max-width: var(--max-width); margin: 0 auto; padding: 0 20px; }

/* ========== Spin 动画 ========== */
@keyframes spin { from { transform: rotate(0deg); } to { transform: rotate(360deg); } }

/* ========== 导航栏 ========== */
.navbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  background: rgba(255,255,255,0.92); backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--tg-border);
}
.navbar-inner {
  max-width: var(--max-width); margin: 0 auto; padding: 0 20px;
  display: flex; align-items: center; justify-content: space-between; height: 64px;
}
.logo {
  display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 1.25rem; color: var(--tg-dark);
}
.logo svg { width: 32px; height: 32px; flex-shrink: 0; }
.nav-links { display: flex; gap: 6px; }
.nav-links a {
  padding: 8px 18px; border-radius: 20px; font-size: 0.95rem; font-weight: 500;
  color: var(--tg-text-light); transition: all 0.2s;
}
.nav-links a:hover { color: var(--tg-blue); background: rgba(36,161,222,0.06); }
.nav-links a.active { color: #fff; background: var(--tg-blue); }
.mobile-menu-btn { display: none; }

/* ========== 按钮样式 ========== */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 14px 32px; border-radius: var(--radius-sm); font-size: 1rem; font-weight: 600;
  transition: transform 0.15s, box-shadow 0.15s, background 0.2s; white-space: nowrap;
}
.btn-primary { background: var(--tg-blue); color: #fff; box-shadow: 0 4px 14px rgba(36,161,222,0.35); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 6px 20px rgba(36,161,222,0.45); background: #1a8fcb; }
.btn-secondary { background: var(--tg-dark); color: #fff; }
.btn-secondary:hover { background: #0e1621; transform: translateY(-2px); }
.btn-outline { background: transparent; color: var(--tg-blue); border: 2px solid var(--tg-blue); }
.btn-outline:hover { background: var(--tg-blue); color: #fff; }
.btn-lg { padding: 16px 40px; font-size: 1.1rem; border-radius: var(--radius); }
.btn-sm { padding: 10px 20px; font-size: 0.9rem; }

/* ========== 板块通用 ========== */
.section { padding: 80px 0; }
.section-alt { background: var(--tg-gray); }
.section-title {
  font-size: 2.2rem; font-weight: 800; text-align: center; margin-bottom: 12px; color: var(--tg-dark);
}
.section-subtitle {
  font-size: 1.1rem; color: var(--tg-text-light); text-align: center; max-width: 640px; margin: 0 auto 48px;
}
.section-header { margin-bottom: 48px; }

/* ========== Hero ========== */
.hero {
  padding: 140px 0 100px; position: relative; overflow: hidden;
  background: linear-gradient(135deg, #0e1621 0%, #17212b 50%, #1c2a3a 100%);
  color: #fff;
}
.hero-bg {
  position: absolute; inset: 0; opacity: 0.08;
  background-image: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='1'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}
.hero-inner { position: relative; z-index: 1; display: flex; align-items: center; gap: 60px; }
.hero-content { flex: 1; }
.hero-badge {
  display: inline-flex; align-items: center; gap: 8px;
  background: rgba(36,161,222,0.15); color: var(--tg-blue);
  padding: 6px 16px; border-radius: 20px; font-size: 0.9rem; font-weight: 500; margin-bottom: 24px;
  border: 1px solid rgba(36,161,222,0.25);
}
.hero-title { font-size: 3.2rem; font-weight: 800; line-height: 1.15; margin-bottom: 20px; }
.hero-desc { font-size: 1.15rem; color: rgba(255,255,255,0.75); max-width: 540px; margin-bottom: 32px; }
.hero-buttons { display: flex; gap: 16px; flex-wrap: wrap; }
.hero-visual { flex: 0 0 420px; display: flex; justify-content: center; align-items: center; }
.hero-visual-box {
  width: 360px; height: 360px; border-radius: 50%; background: rgba(36,161,222,0.12);
  display: flex; justify-content: center; align-items: center; position: relative;
  animation: float 6s ease-in-out infinite;
}
.hero-visual-box::before {
  content: ''; position: absolute; width: 280px; height: 280px; border-radius: 50%;
  background: rgba(36,161,222,0.08);
}
.hero-visual-box svg { width: 160px; height: 160px; position: relative; z-index: 1; filter: drop-shadow(0 10px 30px rgba(36,161,222,0.3)); }
@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-16px); }
}

/* ========== 特性卡片 ========== */
.features-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.feature-card {
  background: var(--tg-card); border-radius: var(--radius); padding: 32px;
  border: 1px solid var(--tg-border); transition: transform 0.2s, box-shadow 0.2s;
}
.feature-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); border-color: transparent; }
.feature-icon {
  width: 56px; height: 56px; border-radius: var(--radius-sm); display: flex; align-items: center; justify-content: center;
  margin-bottom: 20px; background: rgba(36,161,222,0.08);
}
.feature-icon svg { width: 28px; height: 28px; }
.feature-title { font-size: 1.15rem; font-weight: 700; margin-bottom: 10px; color: var(--tg-dark); }
.feature-desc { font-size: 0.95rem; color: var(--tg-text-light); line-height: 1.7; }

/* ========== 下载入口区域 ========== */
.download-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.download-card {
  background: var(--tg-card); border-radius: var(--radius); padding: 28px; text-align: center;
  border: 1px solid var(--tg-border); transition: all 0.2s;
}
.download-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-md); border-color: var(--tg-blue); }
.download-card-icon { margin-bottom: 16px; }
.download-card-icon svg { width: 48px; height: 48px; }
.download-card-title { font-size: 1.1rem; font-weight: 700; margin-bottom: 6px; }
.download-card-desc { font-size: 0.9rem; color: var(--tg-text-light); margin-bottom: 16px; }

/* ========== 功能详细介绍区 ========== */
.detail-row { display: flex; align-items: center; gap: 60px; margin-bottom: 80px; }
.detail-row.reverse { flex-direction: row-reverse; }
.detail-visual {
  flex: 0 0 420px; height: 300px; border-radius: var(--radius);
  background: linear-gradient(135deg, var(--tg-gray) 0%, #eef1f5 100%);
  display: flex; align-items: center; justify-content: center; position: relative; overflow: hidden;
}
.detail-visual svg { width: 180px; height: 180px; }
.detail-content { flex: 1; }
.detail-label {
  display: inline-block; padding: 4px 12px; border-radius: 4px; font-size: 0.8rem; font-weight: 700;
  text-transform: uppercase; letter-spacing: 0.5px; margin-bottom: 12px;
  background: rgba(36,161,222,0.1); color: var(--tg-blue);
}
.detail-title { font-size: 1.8rem; font-weight: 800; margin-bottom: 16px; color: var(--tg-dark); }
.detail-text { font-size: 1.05rem; color: var(--tg-text-light); margin-bottom: 12px; }
.detail-list { margin-top: 16px; }
.detail-list li {
  display: flex; align-items: flex-start; gap: 10px; margin-bottom: 10px;
  font-size: 0.95rem; color: var(--tg-text-light);
}
.detail-list li svg { width: 20px; height: 20px; flex-shrink: 0; margin-top: 2px; }

/* ========== 用户评价 ========== */
.reviews-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.review-card {
  background: var(--tg-card); border-radius: var(--radius); padding: 28px;
  border: 1px solid var(--tg-border);
}
.review-header { display: flex; align-items: center; gap: 12px; margin-bottom: 14px; }
.review-avatar {
  width: 44px; height: 44px; border-radius: 50%; background: linear-gradient(135deg, var(--tg-blue), #1a8fcb);
  display: flex; align-items: center; justify-content: center; color: #fff; font-weight: 700; font-size: 1rem;
}
.review-meta { flex: 1; }
.review-name { font-weight: 700; font-size: 1rem; }
.review-stars { display: flex; gap: 2px; margin-top: 2px; }
.review-stars svg { width: 16px; height: 16px; }
.review-text { font-size: 0.95rem; color: var(--tg-text-light); line-height: 1.75; }

/* ========== 数据统计 ========== */
.stats-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.stat-card {
  background: var(--tg-card); border-radius: var(--radius); padding: 36px 24px; text-align: center;
  border: 1px solid var(--tg-border);
}
.stat-number {
  font-size: 2.8rem; font-weight: 800; color: var(--tg-blue); line-height: 1;
  margin-bottom: 8px; font-variant-numeric: tabular-nums;
}
.stat-label { font-size: 0.95rem; color: var(--tg-text-light); }

/* ========== 对比表格 ========== */
.compare-table-wrap { overflow-x: auto; border-radius: var(--radius); border: 1px solid var(--tg-border); }
.compare-table { width: 100%; border-collapse: collapse; background: var(--tg-card); }
.compare-table th, .compare-table td { padding: 16px 20px; text-align: left; border-bottom: 1px solid var(--tg-border); }
.compare-table th { background: var(--tg-dark); color: #fff; font-weight: 600; font-size: 0.95rem; }
.compare-table td { font-size: 0.95rem; }
.compare-table tr:last-child td { border-bottom: none; }
.compare-table .col-check { color: var(--tg-green); display: flex; align-items: center; gap: 6px; }
.compare-table .col-cross { color: var(--tg-red); display: flex; align-items: center; gap: 6px; }
.compare-table .col-check svg, .compare-table .col-cross svg { width: 18px; height: 18px; flex-shrink: 0; }
.compare-table tr:hover td { background: var(--tg-gray); }

/* ========== FAQ ========== */
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item { border-bottom: 1px solid var(--tg-border); }
.faq-question {
  display: flex; align-items: center; justify-content: space-between;
  padding: 22px 0; font-size: 1.1rem; font-weight: 700; cursor: pointer;
  color: var(--tg-dark); transition: color 0.2s;
}
.faq-question:hover { color: var(--tg-blue); }
.faq-question svg { width: 20px; height: 20px; flex-shrink: 0; transition: transform 0.3s; }
.faq-item.open .faq-question svg { transform: rotate(180deg); }
.faq-answer {
  max-height: 0; overflow: hidden; transition: max-height 0.35s ease, padding 0.35s ease;
  font-size: 0.95rem; color: var(--tg-text-light); line-height: 1.8;
}
.faq-item.open .faq-answer { max-height: 500px; padding-bottom: 22px; }

/* ========== 页脚 ========== */
.footer {
  background: var(--tg-darker); color: rgba(255,255,255,0.7); padding: 48px 0 32px;
}
.footer-inner { max-width: var(--max-width); margin: 0 auto; padding: 0 20px; }
.footer-top { display: flex; justify-content: space-between; align-items: flex-start; margin-bottom: 32px; flex-wrap: wrap; gap: 24px; }
.footer-brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 1.2rem; color: #fff; }
.footer-brand svg { width: 28px; height: 28px; }
.footer-links { display: flex; gap: 28px; flex-wrap: wrap; }
.footer-links a { color: rgba(255,255,255,0.6); font-size: 0.9rem; transition: color 0.2s; }
.footer-links a:hover { color: var(--tg-blue); }
.footer-bottom { border-top: 1px solid rgba(255,255,255,0.1); padding-top: 24px; font-size: 0.85rem; color: rgba(255,255,255,0.5); text-align: center; line-height: 1.8; }

/* ========== 下载页特殊样式 ========== */
.download-hero {
  padding: 140px 0 80px; background: linear-gradient(135deg, #0e1621 0%, #17212b 100%); color: #fff; text-align: center;
}
.download-hero-title { font-size: 2.6rem; font-weight: 800; margin-bottom: 12px; }
.download-hero-desc { font-size: 1.1rem; color: rgba(255,255,255,0.7); max-width: 600px; margin: 0 auto 32px; }
.download-main-card {
  background: var(--tg-card); border-radius: var(--radius); padding: 40px; max-width: 560px; margin: 0 auto;
  text-align: center; color: var(--tg-text); border: 1px solid var(--tg-border);
}
.download-main-card .platform-icon { margin-bottom: 16px; }
.download-main-card .platform-icon svg { width: 64px; height: 64px; }
.download-main-card h3 { font-size: 1.4rem; font-weight: 700; margin-bottom: 8px; color: var(--tg-dark); }
.download-meta { font-size: 0.9rem; color: var(--tg-text-light); margin-bottom: 20px; }
.download-meta span { display: inline-block; margin: 0 8px; }

/* 平台卡片网格 */
.platform-cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.platform-card {
  background: var(--tg-card); border-radius: var(--radius); padding: 32px;
  border: 1px solid var(--tg-border); transition: all 0.2s;
}
.platform-card:hover { box-shadow: var(--shadow-md); border-color: var(--tg-blue); transform: translateY(-2px); }
.platform-card-header { display: flex; align-items: center; gap: 14px; margin-bottom: 16px; }
.platform-card-header svg { width: 40px; height: 40px; }
.platform-card-header h4 { font-size: 1.2rem; font-weight: 700; }
.platform-info { font-size: 0.9rem; color: var(--tg-text-light); margin-bottom: 16px; }
.platform-info p { margin-bottom: 6px; }
.platform-steps { margin-bottom: 20px; }
.platform-steps li {
  display: flex; gap: 10px; font-size: 0.9rem; color: var(--tg-text-light); margin-bottom: 8px;
}
.platform-steps .step-num {
  width: 22px; height: 22px; border-radius: 50%; background: var(--tg-blue); color: #fff;
  display: flex; align-items: center; justify-content: center; font-size: 0.75rem; font-weight: 700; flex-shrink: 0;
}

/* 安装指南 */
.guide-section { margin-bottom: 60px; }
.guide-title { font-size: 1.6rem; font-weight: 800; margin-bottom: 28px; color: var(--tg-dark); display: flex; align-items: center; gap: 10px; }
.guide-title svg { width: 28px; height: 28px; }
.guide-steps { display: flex; flex-direction: column; gap: 20px; }
.guide-step {
  display: flex; gap: 20px; align-items: flex-start;
  background: var(--tg-card); border-radius: var(--radius); padding: 24px; border: 1px solid var(--tg-border);
}
.guide-step-num {
  width: 44px; height: 44px; border-radius: 50%; background: var(--tg-blue); color: #fff;
  display: flex; align-items: center; justify-content: center; font-size: 1.2rem; font-weight: 800; flex-shrink: 0;
}
.guide-step-content h4 { font-size: 1.15rem; font-weight: 700; margin-bottom: 6px; }
.guide-step-content p { font-size: 0.95rem; color: var(--tg-text-light); }

/* 系统要求 */
.sysreq-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.sysreq-card {
  background: var(--tg-card); border-radius: var(--radius); padding: 24px;
  border: 1px solid var(--tg-border);
}
.sysreq-card h4 { font-size: 1.1rem; font-weight: 700; margin-bottom: 12px; display: flex; align-items: center; gap: 8px; }
.sysreq-card h4 svg { width: 22px; height: 22px; }
.sysreq-card ul { font-size: 0.9rem; color: var(--tg-text-light); }
.sysreq-card ul li { margin-bottom: 6px; padding-left: 14px; position: relative; }
.sysreq-card ul li::before { content: '•'; position: absolute; left: 0; color: var(--tg-blue); }

/* 更新日志 */
.changelog-list { max-width: 800px; margin: 0 auto; }
.changelog-item {
  display: flex; gap: 24px; padding: 24px 0; border-bottom: 1px solid var(--tg-border);
}
.changelog-version { flex-shrink: 0; width: 80px; }
.changelog-version .ver-tag {
  display: inline-block; padding: 4px 12px; border-radius: 20px; background: var(--tg-blue); color: #fff;
  font-size: 0.85rem; font-weight: 700;
}
.changelog-version .ver-date { font-size: 0.8rem; color: var(--tg-text-light); margin-top: 6px; }
.changelog-content h4 { font-size: 1.05rem; font-weight: 700; margin-bottom: 8px; }
.changelog-content ul { font-size: 0.9rem; color: var(--tg-text-light); padding-left: 18px; list-style: disc; }
.changelog-content ul li { margin-bottom: 4px; }

/* 安全下载说明 */
.security-box {
  background: linear-gradient(135deg, rgba(36,161,222,0.06) 0%, rgba(52,199,89,0.06) 100%);
  border: 1px solid rgba(36,161,222,0.2); border-radius: var(--radius); padding: 32px;
  display: flex; align-items: flex-start; gap: 20px;
}
.security-box svg { width: 48px; height: 48px; flex-shrink: 0; }
.security-box h3 { font-size: 1.2rem; font-weight: 700; margin-bottom: 8px; }
.security-box p { font-size: 0.95rem; color: var(--tg-text-light); }

/* ========== SEO页特殊样式 ========== */
.seo-hero { padding: 140px 0 80px; background: linear-gradient(135deg, #0e1621 0%, #17212b 100%); color: #fff; }
.seo-hero-inner { display: flex; align-items: center; gap: 50px; }
.seo-hero-content { flex: 1; }
.seo-hero-title { font-size: 2.4rem; font-weight: 800; margin-bottom: 16px; }
.seo-hero-desc { font-size: 1.1rem; color: rgba(255,255,255,0.75); margin-bottom: 28px; }
.seo-cta-box {
  background: var(--tg-card); border-radius: var(--radius); padding: 28px;
  color: var(--tg-text); border: 1px solid var(--tg-border);
}
.seo-cta-box p { font-size: 0.95rem; color: var(--tg-text-light); margin-bottom: 14px; }

.article-content { max-width: 800px; margin: 0 auto; }
.article-content h2 { font-size: 1.6rem; font-weight: 800; margin: 48px 0 20px; color: var(--tg-dark); }
.article-content h3 { font-size: 1.25rem; font-weight: 700; margin: 28px 0 12px; color: var(--tg-dark); }
.article-content p { font-size: 1.05rem; color: var(--tg-text-light); margin-bottom: 16px; line-height: 1.8; }
.article-content ul { padding-left: 22px; margin-bottom: 16px; }
.article-content ul li { font-size: 1.02rem; color: var(--tg-text-light); margin-bottom: 8px; line-height: 1.7; }
.article-content strong { color: var(--tg-dark); }

/* 技巧卡片 */
.tips-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; margin-top: 24px; }
.tip-card {
  background: var(--tg-card); border-radius: var(--radius); padding: 24px;
  border: 1px solid var(--tg-border);
}
.tip-card h4 { font-size: 1.05rem; font-weight: 700; margin-bottom: 8px; display: flex; align-items: center; gap: 8px; }
.tip-card p { font-size: 0.9rem; color: var(--tg-text-light); }

/* ========== 响应式 ========== */
@media (max-width: 1024px) {
  .hero-inner { flex-direction: column; text-align: center; gap: 40px; }
  .hero-content { order: 1; }
  .hero-visual { flex: none; order: 0; }
  .hero-desc { margin-left: auto; margin-right: auto; }
  .hero-buttons { justify-content: center; }
  .detail-row, .detail-row.reverse { flex-direction: column; gap: 30px; }
  .detail-visual { flex: none; width: 100%; }
}
@media (max-width: 900px) {
  .features-grid { grid-template-columns: repeat(2, 1fr); }
  .download-grid { grid-template-columns: repeat(2, 1fr); }
  .reviews-grid { grid-template-columns: repeat(2, 1fr); }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .platform-cards { grid-template-columns: repeat(2, 1fr); }
  .sysreq-grid { grid-template-columns: repeat(2, 1fr); }
  .tips-grid { grid-template-columns: 1fr; }
  .seo-hero-inner { flex-direction: column; }
}
@media (max-width: 640px) {
  .mobile-menu-btn { display: block; background: none; border: none; }
  .mobile-menu-btn svg { width: 28px; height: 28px; }
  .nav-links { display: none; position: absolute; top: 64px; left: 0; right: 0; background: #fff; flex-direction: column; padding: 12px 20px; border-bottom: 1px solid var(--tg-border); gap: 4px; }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 10px 14px; }
  .hero-title { font-size: 2.2rem; }
  .hero-visual-box { width: 260px; height: 260px; }
  .hero-visual-box svg { width: 120px; height: 120px; }
  .features-grid { grid-template-columns: 1fr; }
  .download-grid { grid-template-columns: 1fr; }
  .reviews-grid { grid-template-columns: 1fr; }
  .stats-grid { grid-template-columns: 1fr; }
  .section-title { font-size: 1.7rem; }
  .platform-cards { grid-template-columns: 1fr; }
  .sysreq-grid { grid-template-columns: 1fr; }
  .footer-top { flex-direction: column; align-items: center; text-align: center; }
}

/* ========== 辅助类 ========== */
.text-center { text-align: center; }
.mt-1 { margin-top: 8px; } .mt-2 { margin-top: 16px; } .mt-3 { margin-top: 24px; } .mt-4 { margin-top: 32px; }
.mb-1 { margin-bottom: 8px; } .mb-2 { margin-bottom: 16px; } .mb-3 { margin-bottom: 24px; } .mb-4 { margin-bottom: 32px; }
.w-full { width: 100%; }