/* 课件页通用的爱小课顶栏和页脚：课件内部保留自己的风格，外框统一，老师随时知道自己在爱小课里。
   用法：<link rel="stylesheet" href="/assets/kt-chrome.css">，HTML 结构见 3D 单词、长征、分数样板课页面。 */
.kt-bar,.kt-foot{font:14px/1.6 -apple-system,BlinkMacSystemFont,"Helvetica Neue","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;color:#4b5565;text-align:left}
.kt-bar{background:#fff;border-bottom:1px solid #e5e8ef;position:relative;z-index:5}
.kt-bar .in,.kt-foot .in{max-width:1280px;margin:0 auto;padding:10px 24px;display:flex;align-items:center;gap:16px;flex-wrap:wrap}
.kt-bar a,.kt-foot a{color:#4b5565;text-decoration:none}
.kt-bar a:hover,.kt-foot a:hover{color:#3d5afe}
.kt-bar a:focus-visible,.kt-foot a:focus-visible{outline:2px solid #3d5afe;outline-offset:2px;border-radius:6px}
.kt-bar .logo{display:inline-flex;align-items:center;gap:8px;font-weight:700;color:#111827;font-size:16px;letter-spacing:.5px}
.kt-bar .logo i{width:26px;height:26px;border-radius:8px;background:#3d5afe;color:#fff;display:grid;place-items:center;font-style:normal;font-weight:800;font-size:14px}
.kt-bar .crumbs{color:#6b7280}
.kt-bar .crumbs a{color:#4b5565}
.kt-bar .nav{margin-left:auto;display:flex;gap:18px;align-items:center}
.kt-bar .cta{background:#3d5afe;color:#fff!important;border-radius:9px;padding:5px 12px;font-weight:600}
.kt-bar .cta:hover{background:#2639c9}
.kt-foot{background:#fff;border-top:1px solid #e5e8ef;color:#6b7280}
.kt-foot .in{padding:28px 24px;justify-content:space-between}
.kt-foot nav{display:flex;gap:20px;flex-wrap:wrap}
@media (max-width:720px){
  .kt-bar .in{padding:10px 16px;gap:8px 12px}
  .kt-bar .crumbs{order:3;width:100%;font-size:13px}
  .kt-bar .nav a:not(.cta){display:none}
  .kt-foot .in{padding:22px 16px}
}
@media print{.kt-bar,.kt-foot{display:none}}