/* ============================================================
   有道翻译官网 · 第1套模板样式
   设计方向：清新蓝绿学习风 / 居中 Hero / 功能卡片网格
   ============================================================ */

:root {
  --c-primary: #0ea5a3;
  --c-primary-dark: #0a7a78;
  --c-secondary: #2563eb;
  --c-accent: #22c55e;
  --c-bg: #f4fbfa;
  --c-bg-alt: #eaf7f5;
  --c-card: #ffffff;
  --c-text: #10241f;
  --c-text-muted: #52706b;
  --c-border: #d9efec;
  --radius-lg: 20px;
  --radius-md: 14px;
  --radius-sm: 8px;
  --shadow-sm: 0 2px 10px rgba(14, 165, 163, 0.08);
  --shadow-md: 0 10px 30px rgba(14, 165, 163, 0.14);
  --gradient-brand: linear-gradient(120deg, #0ea5a3 0%, #2563eb 100%);
  --container-w: 1160px;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  background: var(--c-bg);
  color: var(--c-text);
  line-height: 1.7;
  font-size: 16px;
}

img, svg { display: block; }

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

ul { list-style: none; }

.container {
  width: 100%;
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 0 24px;
}

.icon { width: 1em; height: 1em; }

/* ---------------- 导航栏 ---------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: saturate(180%) blur(10px);
  border-bottom: 1px solid var(--c-border);
}

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

.brand {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 20px;
  font-weight: 700;
  color: var(--c-primary-dark);
}

.brand .icon { width: 30px; height: 30px; color: var(--c-primary); }

.main-nav { display: flex; align-items: center; gap: 4px; }

.main-nav a {
  position: relative;
  padding: 9px 16px;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 500;
  color: var(--c-text-muted);
  transition: color 0.2s ease, background-color 0.2s ease;
}

.main-nav a:hover { color: var(--c-primary-dark); background: var(--c-bg-alt); }

.main-nav a.active {
  color: #fff;
  background: var(--gradient-brand);
  box-shadow: var(--shadow-sm);
}

.nav-cta {
  padding: 9px 20px !important;
  color: #fff !important;
  background: var(--c-primary) !important;
  border-radius: 999px;
}

/* ---------------- 通用按钮 ---------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 30px;
  border-radius: 999px;
  font-size: 16px;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: transform 0.18s ease, box-shadow 0.18s ease, opacity 0.18s ease;
}

.btn:disabled { opacity: 0.7; cursor: not-allowed; }

.btn-primary {
  background: var(--gradient-brand);
  color: #fff;
  box-shadow: var(--shadow-md);
}

.btn-primary:hover:not(:disabled) { transform: translateY(-2px); box-shadow: 0 14px 34px rgba(14,165,163,.22); }

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

.btn-outline:hover:not(:disabled) { border-color: var(--c-primary); background: var(--c-bg-alt); }

.btn-block { width: 100%; }
.btn-sm { padding: 10px 18px; font-size: 14px; }

/* ---------------- Hero（居中） ---------------- */
.hero {
  padding: 88px 0 64px;
  text-align: center;
  background:
    radial-gradient(600px 300px at 15% -10%, rgba(14,165,163,.14), transparent),
    radial-gradient(600px 300px at 85% -10%, rgba(37,99,235,.12), transparent);
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 16px;
  border-radius: 999px;
  background: var(--c-bg-alt);
  color: var(--c-primary-dark);
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 22px;
}

.hero h1 {
  font-size: 44px;
  line-height: 1.35;
  font-weight: 800;
  color: var(--c-text);
  max-width: 780px;
  margin: 0 auto 18px;
}

.hero h1 span { background: var(--gradient-brand); -webkit-background-clip: text; background-clip: text; color: transparent; }

.hero-sub {
  max-width: 640px;
  margin: 0 auto 34px;
  color: var(--c-text-muted);
  font-size: 17px;
}

.hero-actions { display: flex; justify-content: center; gap: 16px; flex-wrap: wrap; margin-bottom: 30px; }

.hero-platforms { display: flex; justify-content: center; gap: 26px; flex-wrap: wrap; color: var(--c-text-muted); font-size: 14px; }
.hero-platforms span { display: inline-flex; align-items: center; gap: 6px; }
.hero-platforms .icon { width: 18px; height: 18px; color: var(--c-primary); }

/* ---------------- 通用 Section ---------------- */
section { padding: 76px 0; }
.section-alt { background: var(--c-bg-alt); }

.section-head { text-align: center; max-width: 680px; margin: 0 auto 48px; }
.section-tag { color: var(--c-primary-dark); font-weight: 700; font-size: 14px; letter-spacing: 0.06em; text-transform: uppercase; }
.section-head h2 { font-size: 32px; font-weight: 800; margin: 10px 0 14px; }
.section-head p { color: var(--c-text-muted); font-size: 15.5px; }

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

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

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

.feature-icon {
  width: 52px; height: 52px;
  border-radius: 14px;
  display: flex; align-items: center; justify-content: center;
  background: var(--gradient-brand);
  color: #fff;
  margin-bottom: 18px;
}
.feature-icon .icon { width: 26px; height: 26px; }

.feature-card h3 { font-size: 18.5px; font-weight: 700; margin-bottom: 10px; }
.feature-card p { color: var(--c-text-muted); font-size: 14.5px; }

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

.platform-card {
  background: var(--c-card);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-lg);
  padding: 28px 22px;
  text-align: center;
}

.platform-card .icon-wrap {
  width: 56px; height: 56px; margin: 0 auto 16px;
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  background: var(--c-bg-alt);
  color: var(--c-primary-dark);
}
.platform-card .icon-wrap .icon { width: 28px; height: 28px; }

.platform-card h3 { font-size: 17px; margin-bottom: 6px; }
.platform-card .ver { color: var(--c-text-muted); font-size: 13px; margin-bottom: 18px; }

/* ---------------- 深度功能介绍 ---------------- */
.deep-dive { display: flex; flex-direction: column; gap: 46px; }

.dive-row {
  display: grid;
  grid-template-columns: 90px 1fr;
  gap: 28px;
  align-items: start;
  background: var(--c-card);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-lg);
  padding: 32px;
}

.dive-num {
  width: 60px; height: 60px;
  border-radius: 16px;
  background: var(--c-bg-alt);
  color: var(--c-primary-dark);
  font-size: 22px; font-weight: 800;
  display: flex; align-items: center; justify-content: center;
}

.dive-row h3 { font-size: 20px; margin-bottom: 10px; }
.dive-row p { color: var(--c-text-muted); margin-bottom: 8px; }

/* ---------------- 数据统计 ---------------- */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  text-align: center;
}

.stat-item .num { font-size: 36px; font-weight: 800; color: var(--c-primary-dark); }
.stat-item .label { color: var(--c-text-muted); font-size: 14px; margin-top: 6px; }

/* ---------------- 对比表格 ---------------- */
.compare-table-wrap { overflow-x: auto; border-radius: var(--radius-lg); border: 1px solid var(--c-border); }

table.compare-table { width: 100%; border-collapse: collapse; background: var(--c-card); min-width: 640px; }
table.compare-table th, table.compare-table td {
  padding: 16px 18px;
  text-align: center;
  border-bottom: 1px solid var(--c-border);
  font-size: 14.5px;
}
table.compare-table th:first-child, table.compare-table td:first-child { text-align: left; color: var(--c-text-muted); }
table.compare-table thead th { background: var(--c-bg-alt); font-weight: 700; }
table.compare-table thead th.brand-col { background: var(--gradient-brand); color: #fff; }
table.compare-table td.yes { color: var(--c-primary-dark); font-weight: 700; }
table.compare-table td.no { color: #b3bdba; }

/* ---------------- 用户评价 ---------------- */
.review-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }

.review-card {
  background: var(--c-card);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-lg);
  padding: 26px;
}

.review-stars { color: #f5a524; margin-bottom: 12px; display: flex; gap: 3px; }
.review-stars .icon { width: 16px; height: 16px; }
.review-card p.content { color: var(--c-text); font-size: 14.5px; margin-bottom: 16px; }
.review-user { display: flex; align-items: center; gap: 10px; }
.review-avatar {
  width: 36px; height: 36px; border-radius: 50%;
  background: var(--gradient-brand); color: #fff;
  display: flex; align-items: center; justify-content: center; font-weight: 700; font-size: 14px;
}
.review-user .name { font-weight: 700; font-size: 14px; }
.review-user .role { color: var(--c-text-muted); font-size: 12.5px; }

/* ---------------- FAQ ---------------- */
.faq-list { max-width: 780px; margin: 0 auto; display: flex; flex-direction: column; gap: 14px; }

.faq-item {
  background: var(--c-card);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-md);
  padding: 6px 22px;
}

.faq-item summary {
  cursor: pointer;
  list-style: none;
  padding: 18px 0;
  font-weight: 700;
  font-size: 15.5px;
  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(--c-primary); 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 0 20px; color: var(--c-text-muted); font-size: 14.5px; }

/* ---------------- CTA 区块 ---------------- */
.cta-banner {
  background: var(--gradient-brand);
  border-radius: var(--radius-lg);
  padding: 52px 40px;
  text-align: center;
  color: #fff;
}
.cta-banner h2 { font-size: 28px; margin-bottom: 12px; }
.cta-banner p { opacity: 0.92; margin-bottom: 26px; }
.cta-banner .btn-primary { background: #fff; color: var(--c-primary-dark); box-shadow: none; }
.cta-banner .btn-primary:hover { transform: translateY(-2px); }

/* ---------------- 页脚 ---------------- */
.site-footer { background: #0d2b28; color: #b9d6d2; padding: 48px 0 30px; }
.footer-top { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 30px; margin-bottom: 30px; }
.footer-brand { display: flex; align-items: center; gap: 8px; font-size: 18px; font-weight: 700; color: #fff; margin-bottom: 10px; }
.footer-brand .icon { width: 24px; height: 24px; color: var(--c-primary); }
.footer-desc { max-width: 320px; font-size: 13.5px; color: #9dbdb8; }
.footer-links { display: flex; gap: 46px; flex-wrap: wrap; }
.footer-col h4 { color: #fff; font-size: 14.5px; margin-bottom: 14px; }
.footer-col a { display: block; color: #9dbdb8; font-size: 13.5px; margin-bottom: 10px; }
.footer-col a:hover { color: #fff; }
.footer-security {
  display: flex; align-items: center; gap: 10px;
  padding: 14px 18px; border-radius: var(--radius-sm);
  background: rgba(255,255,255,0.06);
  font-size: 13.5px; color: #cfe8e4; margin-bottom: 18px;
}
.footer-security .icon { width: 18px; height: 18px; color: var(--c-accent); flex-shrink: 0; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,0.08); padding-top: 18px; font-size: 12.5px; color: #7ea19c; line-height: 1.8; }

/* ---------------- 中文页专属 ---------------- */
.article-wrap { max-width: 760px; margin: 0 auto; }
.article-wrap h1 { font-size: 34px; margin-bottom: 16px; }
.article-lead { color: var(--c-text-muted); font-size: 16.5px; margin-bottom: 36px; }
.article-wrap h2 { font-size: 23px; margin: 40px 0 14px; }
.article-wrap p { margin-bottom: 14px; color: #2b423d; }
.article-wrap ul { margin: 14px 0 14px 4px; }
.article-wrap li { position: relative; padding-left: 22px; margin-bottom: 10px; color: #2b423d; }
.article-wrap li::before { content: ""; position: absolute; left: 0; top: 9px; width: 8px; height: 8px; border-radius: 50%; background: var(--gradient-brand); }
.article-cta { margin-top: 46px; text-align: center; padding: 40px; background: var(--c-bg-alt); border-radius: var(--radius-lg); }
.article-cta h2 { margin-top: 0; }

/* ---------------- 下载页专属 ---------------- */
.dl-hero {
  background: var(--gradient-brand);
  border-radius: var(--radius-lg);
  padding: 50px 44px;
  color: #fff;
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 32px;
  align-items: center;
}
.dl-hero h1 { font-size: 30px; margin-bottom: 12px; }
.dl-hero p { opacity: 0.92; margin-bottom: 22px; }
.dl-hero .meta { display: flex; gap: 22px; flex-wrap: wrap; font-size: 13.5px; margin-top: 20px; opacity: 0.9; }
.dl-hero .btn-primary { background: #fff; color: var(--c-primary-dark); }
.dl-panel {
  background: rgba(255,255,255,0.14);
  border-radius: var(--radius-md);
  padding: 22px;
  font-size: 14px;
}
.dl-panel div { display: flex; justify-content: space-between; padding: 8px 0; border-bottom: 1px solid rgba(255,255,255,0.18); }
.dl-panel div:last-child { border-bottom: none; }

.steps { display: flex; flex-direction: column; gap: 18px; }
.step-item { display: grid; grid-template-columns: 44px 1fr; gap: 18px; background: var(--c-card); border: 1px solid var(--c-border); border-radius: var(--radius-md); padding: 22px; }
.step-num { width: 44px; height: 44px; border-radius: 50%; background: var(--gradient-brand); color: #fff; font-weight: 800; display: flex; align-items: center; justify-content: center; }
.step-item h3 { font-size: 16.5px; margin-bottom: 6px; }
.step-item p { color: var(--c-text-muted); font-size: 14px; }

.req-table { width: 100%; border-collapse: collapse; background: var(--c-card); border-radius: var(--radius-lg); overflow: hidden; border: 1px solid var(--c-border); }
.req-table th, .req-table td { padding: 14px 18px; border-bottom: 1px solid var(--c-border); font-size: 14px; text-align: left; }
.req-table thead th { background: var(--c-bg-alt); }

.changelog { display: flex; flex-direction: column; gap: 18px; }
.log-item { display: grid; grid-template-columns: 140px 1fr; gap: 20px; background: var(--c-card); border: 1px solid var(--c-border); border-radius: var(--radius-md); padding: 22px; }
.log-ver { font-weight: 800; color: var(--c-primary-dark); }
.log-date { color: var(--c-text-muted); font-size: 13px; }
.log-item ul { margin-top: 8px; }
.log-item li { position: relative; padding-left: 18px; font-size: 14px; color: var(--c-text-muted); margin-bottom: 6px; }
.log-item li::before { content: "—"; position: absolute; left: 0; color: var(--c-primary); }

.security-box { display: flex; gap: 20px; background: var(--c-bg-alt); border-radius: var(--radius-lg); padding: 28px; }
.security-box .icon { width: 36px; height: 36px; color: var(--c-primary-dark); flex-shrink: 0; }
.security-box h3 { margin-bottom: 8px; font-size: 17px; }
.security-box p { color: var(--c-text-muted); font-size: 14px; }

/* ---------------- 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); }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .dl-hero { grid-template-columns: 1fr; }
  .main-nav { display: none; }
}

@media (max-width: 640px) {
  .hero h1 { font-size: 30px; }
  .feature-grid, .platform-grid, .review-grid, .stats-grid { grid-template-columns: 1fr; }
  .dive-row { grid-template-columns: 1fr; }
  .footer-top { flex-direction: column; }
}