/* ============================================================
   观澜学迹 · web-portal 官网共享样式
   - 与 ../future 完全解耦，零依赖、纯静态
   - 同时承载「官网着陆页（深色）」与「法律/合规页（浅色）」两套样式
   - 品牌色：观澜蓝 #2563EB 渐变（唯一主色），墨蓝 #0F1B33 深底，浅澜 #EAF0FE 点缀
   ============================================================ */

/* ---------- 全局重置 ---------- */
* { box-sizing: border-box; margin: 0; padding: 0; }
html, body {
  font-family: -apple-system, "PingFang SC", "Microsoft YaHei", "Segoe UI", sans-serif;
  color: #1A2B4A;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
body { background: #F7F8FA; }
a { color: #2563EB; text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; }

/* ---------- 顶部导航（深色，全站一致）---------- */
header.topbar {
  background: linear-gradient(135deg, #1E40AF 0%, #2563EB 100%);
  color: #fff;
  padding: 16px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
}
header.topbar .logo { font-size: 18px; font-weight: 700; letter-spacing: 2px; }
header.topbar .logo a { color: #fff; }
header.topbar .logo a:hover { text-decoration: none; }
header.topbar .logo img { height: 30px; display: block; }
header.topbar nav a { color: #DBEAFE; margin-left: 20px; font-size: 14px; }
header.topbar nav a:hover { color: #fff; }
@media (max-width: 640px) {
  header.topbar { flex-direction: column; align-items: flex-start; }
  header.topbar nav { display: flex; flex-wrap: wrap; gap: 4px 0; }
  header.topbar nav a { margin-left: 0; margin-right: 16px; }
}

/* ============================================================
   一、官网着陆页（index.html）样式
   ============================================================ */

/* 主视觉区 */
.hero {
  position: relative;
  overflow: hidden;
  background: linear-gradient(135deg, #1E40AF 0%, #2563EB 50%, #4F8BFF 100%);
  color: #fff;
  padding: 72px 24px 88px;
  text-align: center;
}
/* 品牌辅助图形：涟漪水波纹（右上 + 左下，低透明叠加） */
.hero::before, .hero::after {
  content: ""; position: absolute; z-index: 0;
  width: 460px; height: 460px;
  background: url("ripple.svg") no-repeat center / contain;
  pointer-events: none;
}
.hero::before { top: -150px; right: -120px; }
.hero::after { bottom: -190px; left: -140px; opacity: 0.7; }
.hero > * { position: relative; z-index: 1; }
.hero .brand {
  font-size: 13px; letter-spacing: 4px; opacity: 0.7; margin-bottom: 14px;
}
.hero h1 { font-size: 42px; line-height: 1.18; font-weight: 700; margin-bottom: 14px; }
.hero .tagline { font-size: 20px; opacity: 0.9; margin-bottom: 22px; }
.hero .desc {
  max-width: 680px; margin: 0 auto 34px;
  font-size: 16px; line-height: 1.8; opacity: 0.92;
}
.hero .actions {
  display: flex; flex-wrap: wrap; gap: 12px; justify-content: center;
}

/* 通用按钮 */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 13px 26px; border-radius: 10px;
  background: rgba(255,255,255,0.16);
  border: 1px solid rgba(255,255,255,0.25);
  color: #fff; text-decoration: none; font-size: 15px; font-weight: 500;
  transition: all 0.2s;
}
.btn:hover { background: rgba(255,255,255,0.28); transform: translateY(-2px); text-decoration: none; }
.btn.primary { background: #fff; color: #2563EB; border-color: #fff; font-weight: 600; }
.btn.primary:hover { background: #EAF0FE; border-color: #EAF0FE; }
.btn.ghost-dark { background: #2563EB; color: #fff; border-color: #2563EB; }
.btn.ghost-dark:hover { background: #1d4ed8; }

/* 内容区块通用容器 */
.section { max-width: 1040px; margin: 0 auto; padding: 64px 24px; }
.section h2 {
  font-size: 28px; font-weight: 700; color: #0F1B33;
  text-align: center; margin-bottom: 10px;
}
.section .section-sub {
  text-align: center; color: #6B7A90; font-size: 15px; margin-bottom: 40px;
}

/* 功能亮点网格 */
.features {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
}
.feature-card {
  position: relative;
  overflow: hidden;
  background: #fff;
  border: 1px solid #e3e9f0;
  border-radius: 12px;
  padding: 26px 24px;
  transition: box-shadow 0.2s, transform 0.2s;
}
/* 卡片顶饰：右上角涟漪水印（观澜母题，极淡） */
.feature-card::after {
  content: ""; position: absolute; top: -56px; right: -56px;
  width: 150px; height: 150px;
  background: url("ripple-blue.svg") no-repeat center / contain;
  opacity: 0.5; pointer-events: none;
}
.feature-card:hover { box-shadow: 0 12px 30px rgba(26,58,82,0.10); transform: translateY(-3px); }
.feature-card .ico {
  width: 48px; height: 48px; border-radius: 12px;
  background: #EAF0FE;
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 16px;
}
.feature-card h3 { font-size: 18px; color: #1E40AF; margin-bottom: 8px; }
.feature-card p { font-size: 14px; color: #6B7A90; line-height: 1.7; }

/* 学习闭环步骤条 */
.steps {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 16px;
}
.step {
  background: #EAF0FE; border-radius: 12px; padding: 22px 20px; text-align: center;
}
.step .num {
  display: inline-flex; align-items: center; justify-content: center;
  width: 36px; height: 36px; border-radius: 50%;
  background: #2563EB; color: #fff; font-weight: 700; margin-bottom: 12px;
}
.step h4 { font-size: 16px; color: #1E40AF; margin-bottom: 6px; }
.step p { font-size: 13px; color: #6B7A90; }

/* 下载引导区 */
.download {
  background: #0F1B33;
  color: #fff;
}
.download .section h2 { color: #fff; }
.download .section .section-sub { color: #9AA4B2; }
.download-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 20px;
}
.download-card {
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(255,255,255,0.16);
  border-radius: 14px;
  padding: 28px 24px;
  text-align: center;
}
.download-card .qr {
  width: 120px; height: 120px; margin: 0 auto 16px;
  background: repeating-linear-gradient(45deg, #fff, #fff 6px, #DBEAFE 6px, #DBEAFE 12px);
  border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  color: #1E40AF; font-size: 12px; font-weight: 600;
}
.download-card h3 { font-size: 17px; margin-bottom: 6px; }
.download-card p { font-size: 13px; color: #9AA4B2; margin-bottom: 14px; }

/* 合规中心链接区 */
.legal-zone { background: #F2F6FE; }
.legal-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 12px;
}
.legal-grid a {
  display: block;
  font-size: 14px; color: #1E40AF;
  padding: 14px 18px; border-radius: 10px;
  background: #fff; border: 1px solid #e3e9f0;
  transition: all 0.15s;
}
.legal-grid a:hover { background: #EAF0FE; border-color: #B9CCEC; text-decoration: none; }

/* ============================================================
   二、法律 / 合规页（privacy.html 等）样式
   ============================================================ */
main {
  max-width: 920px;
  margin: 0 auto;
  padding: 40px 24px 80px;
}
main h1 { font-size: 28px; font-weight: 700; color: #0F1B33; margin-bottom: 8px; }
main .meta {
  color: #6B7A90; font-size: 13px; margin-bottom: 28px;
  padding-bottom: 16px; border-bottom: 1px solid #e0e6ed;
}
main h2 {
  font-size: 20px; font-weight: 700; color: #1E40AF;
  margin-top: 36px; margin-bottom: 12px;
}
main h3 {
  font-size: 16px; font-weight: 600; color: #2563EB;
  margin-top: 24px; margin-bottom: 8px;
}
main p, main li { font-size: 15px; }
main p { margin-bottom: 14px; }
main ul, main ol { padding-left: 24px; margin-bottom: 14px; }
main li { margin-bottom: 6px; }
main code {
  background: #EAF0FE; padding: 1px 6px; border-radius: 4px;
  font-size: 13px; color: #1E40AF;
}
main table {
  width: 100%; border-collapse: collapse; margin: 16px 0;
  font-size: 14px; background: #fff; border: 1px solid #d9e0e7;
}
main th, main td { padding: 10px 12px; text-align: left; border-bottom: 1px solid #e0e6ed; }
main th { background: #EAF0FE; font-weight: 600; color: #1E40AF; }

/* 提示框 */
.callout {
  background: #fff8e1; border-left: 4px solid #F59E0B;
  padding: 14px 18px; margin: 18px 0; border-radius: 4px; font-size: 14px;
}
.callout-danger { background: #ffeaea; border-left-color: #E5484D; }
.callout-info { background: #EAF0FE; border-left-color: #2563EB; }

/* 联系卡片 */
.contact-card {
  background: #fff; border: 1px solid #d9e0e7; border-radius: 8px;
  padding: 18px 22px; margin: 16px 0;
}
.contact-card .label { color: #6B7A90; font-size: 13px; }
.contact-card .value { font-size: 16px; font-weight: 600; color: #1E40AF; margin-top: 4px; }

/* ---------- 全站页脚 ---------- */
footer.site {
  background: #1E40AF; color: #9AA4B2;
  padding: 28px 24px; font-size: 13px; text-align: center;
}
footer.site .links a { color: #DBEAFE; margin: 0 10px; }
footer.site .icp { margin-top: 10px; opacity: 0.7; line-height: 1.8; }

/* ============================================================
   三、极简单屏落地页（首页，参考 future 风格 · 观澜蓝）
   ============================================================ */
/* 全屏 hero：内容居中铺开，PC 端占满视口（非小卡片），手机端自适应收紧 */
.hero-card-wrap {
  position: relative; overflow: hidden;
  /* 全屏铺满：覆盖法律页 main{max-width/margin} 约束 */
  width: 100%; max-width: none; margin: 0;
  min-height: 100vh; min-height: 100dvh;
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  padding: 56px 24px 88px;
  background: linear-gradient(135deg, #1E40AF 0%, #2563EB 50%, #4F8BFF 100%);
}
/* 涟漪母题：四角铺开，随屏放大填满留白 */
.hero-card-wrap::before, .hero-card-wrap::after {
  content: ""; position: absolute; z-index: 0; pointer-events: none;
  width: clamp(420px, 42vw, 760px); height: clamp(420px, 42vw, 760px);
  background: url("ripple.svg") no-repeat center / contain;
}
.hero-card-wrap::before { top: -14vw; right: -10vw; }
.hero-card-wrap::after { bottom: -16vw; left: -12vw; opacity: 0.7; }
.hero-card {
  position: relative; z-index: 1;
  width: 100%; max-width: 820px;
  text-align: center;
  color: #fff;
}
.hero-card .hero-logo { height: clamp(44px, 4.5vw, 64px); display: block; margin: 0 auto 28px; }
.hero-card h1 { font-size: clamp(30px, 5.2vw, 56px); font-weight: 700; letter-spacing: 1px; line-height: 1.15; margin-bottom: 12px; }
.hero-card .lead { font-size: clamp(17px, 2vw, 24px); opacity: 0.92; margin-bottom: 24px; }
.hero-card .intro { font-size: clamp(15px, 1.4vw, 18px); line-height: 1.9; opacity: 0.9; max-width: 660px; margin: 0 auto 36px; }
.hero-card .cta { display: flex; gap: 14px; flex-wrap: wrap; justify-content: center; }
.hero-card .cta .btn { padding: 14px 32px; font-size: 16px; }
/* 页脚固定在视口底部居中 */
.card-foot { position: absolute; left: 0; right: 0; bottom: 24px; z-index: 1; text-align: center; padding: 0 24px; font-size: 13px; color: #fff; }
.card-foot .links a { color: rgba(255, 255, 255, 0.85); }
.card-foot .links a:hover { color: #fff; }
.card-foot .icp { margin-top: 8px; opacity: 0.6; line-height: 1.8; font-size: 12px; }
@media (max-width: 520px) {
  .hero-card-wrap { padding: 48px 22px 110px; }
  .card-foot { position: static; margin-top: 40px; }
}