/* ========================================
   套1：清新蓝绿学习风
   居中 Hero + 功能卡片网格
   ======================================== */
:root {
  --primary: #0091ff;
  --primary-dark: #0072cc;
  --accent: #00c9a7;
  --bg: #f6fbfa;
  --text: #17324a;
  --text-light: #5b7286;
  --card-bg: #ffffff;
  --border: #e1eef0;
  --radius: 16px;
  --shadow: 0 8px 24px rgba(0, 145, 255, 0.08);
}

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

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
}

a { color: inherit; text-decoration: none; }
img, svg { display: block; }
ul { list-style: none; }

.container {
  max-width: 1160px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- 导航 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}

.nav-wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 20px;
  font-weight: 700;
  color: var(--primary-dark);
}

.brand svg { width: 32px; height: 32px; }

.nav-links {
  display: flex;
  gap: 8px;
}

.nav-links a {
  padding: 9px 18px;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 500;
  color: var(--text-light);
  transition: all 0.2s ease;
}

.nav-links a:hover { background: #eaf6f5; color: var(--primary-dark); }

.nav-links a.active {
  background: linear-gradient(90deg, var(--primary), var(--accent));
  color: #fff;
}

.nav-cta {
  padding: 10px 22px;
  border-radius: 999px;
  background: var(--primary-dark);
  color: #fff;
  font-size: 14px;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.nav-cta:hover { transform: translateY(-1px); box-shadow: var(--shadow); }

/* ---------- Hero（居中） ---------- */
.hero {
  text-align: center;
  padding: 88px 24px 64px;
  background: radial-gradient(circle at 50% -10%, #e4f7f4 0%, var(--bg) 60%);
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 16px;
  border-radius: 999px;
  background: #e3f8f4;
  color: var(--primary-dark);
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 24px;
}

.hero h1 {
  font-size: 44px;
  font-weight: 800;
  line-height: 1.35;
  margin-bottom: 20px;
  background: linear-gradient(90deg, var(--primary-dark), var(--accent));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero p.subtitle {
  max-width: 640px;
  margin: 0 auto 32px;
  font-size: 17px;
  color: var(--text-light);
}

.hero-actions {
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 30px;
  border-radius: 999px;
  font-size: 16px;
  font-weight: 700;
  border: none;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease, opacity 0.2s ease;
}

.btn:disabled { opacity: 0.7; cursor: default; }

.btn-primary {
  background: linear-gradient(90deg, var(--primary), var(--accent));
  color: #fff;
  box-shadow: var(--shadow);
}

.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 12px 28px rgba(0, 145, 255, 0.22); }

.btn-outline {
  background: #fff;
  color: var(--primary-dark);
  border: 1.5px solid var(--border);
}

.btn-outline:hover { border-color: var(--primary); }

.hero-stats {
  display: flex;
  justify-content: center;
  gap: 48px;
  margin-top: 56px;
  flex-wrap: wrap;
}

.hero-stats .stat-num { font-size: 28px; font-weight: 800; color: var(--primary-dark); }
.hero-stats .stat-label { font-size: 13px; color: var(--text-light); margin-top: 4px; }

/* ---------- 通用 section ---------- */
section { padding: 72px 0; }

.section-head { text-align: center; max-width: 640px; margin: 0 auto 44px; }
.section-tag { color: var(--primary); font-weight: 700; font-size: 14px; letter-spacing: 1px; text-transform: uppercase; }
.section-head h2 { font-size: 32px; font-weight: 800; margin: 10px 0 12px; }
.section-head p { color: var(--text-light); font-size: 15px; }

/* ---------- 特性卡片网格 ---------- */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 30px 26px;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.feature-card:hover { transform: translateY(-4px); box-shadow: var(--shadow); }

.feature-icon {
  width: 52px;
  height: 52px;
  border-radius: 14px;
  background: linear-gradient(135deg, #e5f8f5, #dcefff);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 18px;
}

.feature-icon svg { width: 26px; height: 26px; color: var(--primary-dark); }

.feature-card h3 { font-size: 18px; font-weight: 700; margin-bottom: 10px; }
.feature-card p { color: var(--text-light); font-size: 14.5px; }

/* ---------- 平台下载 ---------- */
.platform-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.platform-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 26px 20px;
  text-align: center;
}

.platform-card .p-icon {
  width: 46px; height: 46px; margin: 0 auto 14px;
  display: flex; align-items: center; justify-content: center;
  border-radius: 12px; background: #eefaf8;
}
.platform-card .p-icon svg { width: 24px; height: 24px; color: var(--primary-dark); }
.platform-card h4 { font-size: 16px; font-weight: 700; margin-bottom: 6px; }
.platform-card .p-desc { font-size: 13px; color: var(--text-light); margin-bottom: 16px; min-height: 40px; }

.btn-block { width: 100%; justify-content: center; }
.btn-sm { padding: 10px 16px; font-size: 14px; }

/* ---------- 深入介绍（图文段落） ---------- */
.deep-intro { background: #fff; }
.deep-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
  padding: 40px 0;
  border-bottom: 1px solid var(--border);
}
.deep-row:last-child { border-bottom: none; }
.deep-row:nth-child(even) { direction: rtl; }
.deep-row:nth-child(even) > * { direction: ltr; }

.deep-visual {
  aspect-ratio: 4/3;
  border-radius: var(--radius);
  background: linear-gradient(135deg, #e4f7f4, #e8f2ff);
  display: flex;
  align-items: center;
  justify-content: center;
}
.deep-visual svg { width: 96px; height: 96px; color: var(--primary); }

.deep-text .step-tag { color: var(--accent); font-weight: 700; font-size: 13px; }
.deep-text h3 { font-size: 24px; font-weight: 800; margin: 8px 0 14px; }
.deep-text p { color: var(--text-light); margin-bottom: 10px; }

/* ---------- 用户评价 ---------- */
.review-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}
.review-card {
  background: var(--card-bg);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  padding: 24px;
}
.stars { display: flex; gap: 3px; margin-bottom: 12px; }
.stars svg { width: 16px; height: 16px; color: #ffb800; }
.review-card p.quote { font-size: 14.5px; color: var(--text); margin-bottom: 14px; }
.review-who { display: flex; align-items: center; gap: 10px; }
.review-avatar {
  width: 36px; height: 36px; border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: #fff; display: flex; align-items: center; justify-content: center;
  font-weight: 700; font-size: 14px;
}
.review-name { font-size: 14px; font-weight: 700; }
.review-role { font-size: 12px; color: var(--text-light); }

/* ---------- 对比表格 ---------- */
.compare-table-wrap { overflow-x: auto; border-radius: var(--radius); border: 1px solid var(--border); }
table.compare-table { width: 100%; border-collapse: collapse; background: #fff; min-width: 640px; }
table.compare-table th, table.compare-table td {
  padding: 16px 20px; text-align: center; border-bottom: 1px solid var(--border); font-size: 14px;
}
table.compare-table th { background: #f1faf9; font-weight: 700; }
table.compare-table td:first-child, table.compare-table th:first-child { text-align: left; font-weight: 600; }
table.compare-table td.yes { color: var(--primary-dark); font-weight: 700; }
table.compare-table .col-youdao { background: #eafbf8; }

/* ---------- FAQ ---------- */
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item {
  border: 1px solid var(--border);
  border-radius: 12px;
  margin-bottom: 12px;
  background: #fff;
  overflow: hidden;
}
.faq-item summary {
  padding: 18px 22px;
  font-size: 15.5px;
  font-weight: 700;
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary .chevron { width: 18px; height: 18px; color: var(--text-light); transition: transform 0.2s ease; flex-shrink: 0; margin-left: 12px; }
.faq-item[open] summary .chevron { transform: rotate(180deg); }
.faq-item .faq-answer { padding: 0 22px 18px; color: var(--text-light); font-size: 14.5px; }

/* ---------- CTA 区块 ---------- */
.cta-band {
  background: linear-gradient(120deg, var(--primary-dark), var(--accent));
  border-radius: 24px;
  padding: 56px;
  text-align: center;
  color: #fff;
  margin: 0 24px;
}
.cta-band h2 { font-size: 28px; font-weight: 800; margin-bottom: 12px; }
.cta-band p { opacity: 0.9; margin-bottom: 28px; }
.cta-band .btn-primary { background: #fff; color: var(--primary-dark); }

/* ---------- 版本更新日志 ---------- */
.changelog { max-width: 760px; margin: 0 auto; }
.changelog-item { display: flex; gap: 20px; padding: 20px 0; border-bottom: 1px solid var(--border); }
.changelog-item:last-child { border-bottom: none; }
.changelog-ver { flex-shrink: 0; width: 120px; }
.changelog-ver .v { font-weight: 800; color: var(--primary-dark); font-size: 15px; }
.changelog-ver .d { font-size: 12px; color: var(--text-light); }
.changelog-body h4 { font-size: 15px; margin-bottom: 6px; }
.changelog-body ul { color: var(--text-light); font-size: 14px; }
.changelog-body ul li { margin-bottom: 4px; padding-left: 14px; position: relative; }
.changelog-body ul li::before { content: ""; position: absolute; left: 0; top: 9px; width: 5px; height: 5px; border-radius: 50%; background: var(--accent); }

/* ---------- 安装步骤 ---------- */
.steps { display: grid; grid-template-columns: repeat(5, 1fr); gap: 16px; }
.step-card { background: #fff; border: 1px solid var(--border); border-radius: var(--radius); padding: 22px 16px; text-align: center; position: relative; }
.step-num { width: 32px; height: 32px; border-radius: 50%; background: var(--primary); color: #fff; display: flex; align-items: center; justify-content: center; font-weight: 800; margin: 0 auto 12px; }
.step-card h4 { font-size: 14.5px; margin-bottom: 6px; }
.step-card p { font-size: 12.5px; color: var(--text-light); }

/* ---------- 系统要求表 ---------- */
.sysreq-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }
.sysreq-card { background: #fff; border: 1px solid var(--border); border-radius: var(--radius); padding: 24px; }
.sysreq-card h4 { display: flex; align-items: center; gap: 10px; font-size: 16px; margin-bottom: 14px; }
.sysreq-card h4 svg { width: 22px; height: 22px; color: var(--primary-dark); }
.sysreq-card table { width: 100%; font-size: 14px; }
.sysreq-card table td { padding: 7px 0; border-bottom: 1px dashed var(--border); }
.sysreq-card table td:first-child { color: var(--text-light); width: 40%; }

/* ---------- 主下载区（下载页顶部） ---------- */
.download-hero {
  background: linear-gradient(135deg, #eafbf8, #e6f2ff);
  border-radius: 24px;
  margin: 0 24px;
  padding: 56px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 40px;
  flex-wrap: wrap;
}
.download-hero .dl-info h1 { font-size: 30px; font-weight: 800; margin-bottom: 12px; }
.download-hero .dl-meta { display: flex; gap: 20px; margin: 16px 0 24px; font-size: 13.5px; color: var(--text-light); flex-wrap: wrap; }
.download-hero .dl-meta span { display: flex; align-items: center; gap: 6px; }
.download-hero .dl-meta svg { width: 15px; height: 15px; }
.download-badge-row { display: flex; align-items: center; gap: 14px; }
.download-badge-row svg { width: 64px; height: 64px; color: var(--primary-dark); }

/* ---------- 安全下载保障 ---------- */
.security-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.security-card { text-align: center; padding: 20px; }
.security-card svg { width: 40px; height: 40px; color: var(--accent); margin: 0 auto 12px; }
.security-card h4 { font-size: 15px; margin-bottom: 6px; }
.security-card p { font-size: 13.5px; color: var(--text-light); }

/* ---------- zh-cn 软文页 ---------- */
.article-wrap { max-width: 760px; margin: 0 auto; }
.article-wrap h1 { font-size: 32px; margin-bottom: 8px; }
.article-wrap .lead { color: var(--text-light); margin-bottom: 32px; font-size: 15.5px; }
.article-wrap h2 { font-size: 22px; margin: 36px 0 14px; }
.article-wrap h3 { font-size: 17px; margin: 22px 0 10px; }
.article-wrap p { margin-bottom: 14px; color: var(--text); }
.article-wrap ul { margin: 0 0 16px 0; }
.article-wrap ul li { padding-left: 20px; position: relative; margin-bottom: 8px; color: var(--text); }
.article-wrap ul li::before { content: ""; position: absolute; left: 4px; top: 9px; width: 6px; height: 6px; border-radius: 50%; background: var(--primary); }
.article-cta { text-align: center; padding: 40px; margin-top: 40px; background: #eafbf8; border-radius: var(--radius); }
.article-cta h3 { margin-bottom: 16px; }

/* ---------- 页脚 ---------- */
.site-footer {
  background: #0f2436;
  color: #b9cdd8;
  padding: 48px 0 28px;
  margin-top: 40px;
}
.footer-security {
  display: flex;
  align-items: center;
  gap: 10px;
  padding-bottom: 24px;
  border-bottom: 1px solid rgba(255,255,255,0.1);
  margin-bottom: 20px;
  font-size: 14px;
  color: #dff5f1;
}
.footer-security svg { width: 20px; height: 20px; color: var(--accent); flex-shrink: 0; }
.footer-links { display: flex; gap: 24px; margin-bottom: 20px; flex-wrap: wrap; }
.footer-links a { font-size: 13.5px; color: #b9cdd8; }
.footer-links a:hover { color: #fff; }
.footer-copy { font-size: 12.5px; color: #8199a8; line-height: 1.8; }

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

/* ---------- 响应式 ---------- */
@media (max-width: 960px) {
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .platform-grid { grid-template-columns: repeat(2, 1fr); }
  .review-grid { grid-template-columns: repeat(2, 1fr); }
  .deep-row { grid-template-columns: 1fr; }
  .deep-row:nth-child(even) { direction: ltr; }
  .steps { grid-template-columns: repeat(3, 1fr); }
  .sysreq-grid { grid-template-columns: 1fr; }
  .nav-links { display: none; }
}
@media (max-width: 640px) {
  .feature-grid, .platform-grid, .review-grid { grid-template-columns: 1fr; }
  .hero h1 { font-size: 30px; }
  .steps { grid-template-columns: repeat(2, 1fr); }
  .download-hero { padding: 32px; }
}