/* 幼小初学习 TV · 10-foot UI，遥控器焦点优先
 * 兼容性目标：Chromium 50+（覆盖 2015 年后的绝大多数安卓智能电视 WebView）
 *   ✗ 不用 aspect-ratio（Chromium 88+）→ 改 padding-bottom 撑高
 *   ✗ 不用 inset 简写（Chromium 87+）  → 拆成 top/right/bottom/left
 */
:root{
  --bg:#0b0e14; --bg2:#111624; --card:#161d2e; --line:#232c42;
  --fg:#eaf0ff; --fg2:#8fa0c0; --accent:#3ea6ff; --accent2:#7be3a8; --warn:#ffd166;
  --radius:10px;
}
*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}
html,body{margin:0;height:100%;overflow:hidden;background:var(--bg);color:var(--fg);
  font-family:"PingFang SC","Microsoft YaHei","Noto Sans SC",system-ui,sans-serif}

#topbar{position:fixed;top:0;left:0;right:0;height:74px;display:flex;align-items:center;gap:30px;
  padding:0 44px;z-index:50;transition:background .3s;
  background:linear-gradient(180deg,rgba(11,14,20,.96),rgba(11,14,20,.55) 70%,transparent)}
#topbar.solid{background:rgba(11,14,20,.98);border-bottom:1px solid var(--line)}
.brand{font-size:25px;font-weight:600;letter-spacing:1px;display:flex;align-items:center;gap:9px;white-space:nowrap}
.brand b{color:var(--accent2)}
.brand .dot{width:11px;height:11px;border-radius:50%;background:var(--accent2);box-shadow:0 0 12px var(--accent2)}
#nav{display:flex;gap:4px;flex:1;overflow:hidden}
.nav-item{color:var(--fg2);text-decoration:none;font-size:18px;padding:9px 15px;border-radius:8px;
  transition:all .18s;outline:none;white-space:nowrap;border:2px solid transparent}
.nav-item.active{color:#fff;background:rgba(62,166,255,.14)}
.nav-item.focused,.nav-item:focus{color:#06111f;background:var(--accent);transform:scale(1.06);
  box-shadow:0 6px 22px rgba(62,166,255,.45);border-color:#fff}
.clock{font-size:16px;color:var(--fg2);font-variant-numeric:tabular-nums}

#view{position:absolute;top:74px;left:0;right:0;bottom:0;overflow-y:auto;overflow-x:hidden;
  padding:10px 44px 70px;scroll-behavior:smooth}
#view::-webkit-scrollbar{width:8px}
#view::-webkit-scrollbar-thumb{background:#2a3550;border-radius:4px}

/* 学段卡 */
.stage-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:18px;margin-bottom:32px}
.stage-card{background:linear-gradient(150deg,#1a2438,#131a28);border:3px solid transparent;
  border-radius:14px;padding:24px 26px;cursor:pointer;outline:none;transition:.2s;position:relative;overflow:hidden}
.stage-card::after{content:'';position:absolute;right:-30px;top:-30px;width:110px;height:110px;border-radius:50%;
  background:radial-gradient(circle,rgba(62,166,255,.22),transparent 70%)}
.stage-card .sc-name{font-size:27px;font-weight:700;margin-bottom:8px}
.stage-card .sc-desc{font-size:15px;color:var(--fg2);margin-bottom:14px}
.stage-card .sc-count{font-size:15px;color:var(--accent2);font-weight:600}
.stage-card.focused,.stage-card:focus{border-color:#fff;background:linear-gradient(150deg,#1f3a5c,#16233a);
  transform:translateY(-4px) scale(1.02);box-shadow:0 14px 34px rgba(0,0,0,.6)}

/* 学科胶囊 */
.chips{display:flex;gap:11px;flex-wrap:wrap;margin-bottom:22px;align-items:center}
.chip{padding:8px 19px;border-radius:20px;background:var(--card);border:2px solid var(--line);
  font-size:16px;cursor:pointer;outline:none;color:var(--fg2);transition:.18s;white-space:nowrap}
.chip.on{background:rgba(62,166,255,.18);color:var(--accent);border-color:var(--accent)}
.chip.focused,.chip:focus{background:var(--accent);color:#06111f;border-color:#fff;transform:scale(1.06)}
.chips .label{font-size:15px;color:var(--fg2);margin-right:6px}

/* 海报行 */
.row{margin-bottom:32px}
.row-head{display:flex;align-items:baseline;gap:14px;margin-bottom:14px}
.row-title{font-size:23px;font-weight:600}
.row-sub{font-size:14.5px;color:var(--fg2)}
.row-track{display:flex;gap:16px;overflow-x:auto;padding:12px 10px 18px;scroll-behavior:smooth}
.row-track::-webkit-scrollbar{height:0}

/* 通用卡片（缩略图用 padding-bottom 撑出 3:4，兼容老 WebView） */
.card{flex:0 0 auto;width:186px;cursor:pointer;outline:none;border-radius:var(--radius);
  transition:transform .18s,box-shadow .18s;border:3px solid transparent}
.grid .card{width:auto}
.card .thumb{width:100%;height:0;padding-bottom:133.333%;border-radius:var(--radius);
  background:#1b2333 center/cover no-repeat;
  position:relative;overflow:hidden;box-shadow:0 6px 18px rgba(0,0,0,.45)}
.card.wide .thumb{padding-bottom:150%}
.card .thumb::after{content:'';position:absolute;top:0;right:0;bottom:0;left:0;
  background:linear-gradient(180deg,transparent 55%,rgba(0,0,0,.72))}
.card .badge{position:absolute;right:7px;top:7px;background:rgba(0,0,0,.72);color:#fff;font-size:12px;
  padding:3px 7px;border-radius:5px;z-index:2;max-width:84%;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.card .tag{position:absolute;left:7px;top:7px;background:rgba(62,166,255,.9);color:#06111f;font-size:12px;
  padding:3px 8px;border-radius:5px;z-index:2;font-weight:600}
.card .kind{position:absolute;left:0;right:0;bottom:0;padding:6px 9px;font-size:12px;color:#dfe8f8;
  background:linear-gradient(0deg,rgba(0,0,0,.85),transparent)}
.card .name{margin-top:9px;font-size:15px;line-height:1.35;color:#cfdaee;
  display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden;height:41px}
.card .sub{margin-top:3px;font-size:13px;color:var(--fg2);height:18px;overflow:hidden;white-space:nowrap;text-overflow:ellipsis}
.card.focused,.card:focus{transform:scale(1.08);z-index:9;
  box-shadow:0 12px 34px rgba(0,0,0,.7),0 0 0 4px var(--accent);border-color:#fff}
.card.focused .name{color:#fff}

.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(178px,1fr));gap:22px 18px;padding:6px 10px 30px}

h2.page-title{font-size:29px;margin:6px 0 18px;font-weight:700}
h2.page-title small{font-size:15px;color:var(--fg2);font-weight:400;margin-left:14px}
.section-t{font-size:21px;font-weight:600;margin:28px 0 12px;display:flex;align-items:center;gap:12px}
.section-t::before{content:'';width:4px;height:19px;background:var(--accent);border-radius:2px}

.btn,.key,.ep,.detail-act,.pbtn,.rd-btn,.rd-nav{outline:none}
.btn{display:inline-block;background:var(--card);border:2px solid var(--line);color:var(--fg);
  padding:11px 26px;border-radius:8px;font-size:18px;cursor:pointer;transition:.18s}
.btn.focused,.btn:focus{background:var(--accent);color:#06111f;border-color:#fff;transform:scale(1.05)}

.loading{padding:70px 0;text-align:center;color:var(--fg2);font-size:19px}
.spin{display:inline-block;width:22px;height:22px;border:3px solid #2b3450;border-top-color:var(--accent);
  border-radius:50%;animation:sp .8s linear infinite;margin-right:10px;vertical-align:-4px}
@keyframes sp{to{transform:rotate(360deg)}}
.empty{padding:70px 0;text-align:center;color:var(--fg2);font-size:19px}
.pill{display:inline-block;font-size:13px;color:var(--accent2);border:1px solid rgba(123,227,168,.4);
  border-radius:20px;padding:2px 11px;margin-left:8px}

/* 视频课（统一课程库） */
.page{padding:0 10px 30px}
.page-head{margin-bottom:20px}
.page-head h1{font-size:30px;font-weight:700;margin-bottom:8px}
.page-head p{font-size:15px;color:var(--fg2)}
.page-head b{color:var(--accent)}
.card .noimg{position:absolute;top:0;right:0;bottom:0;left:0;display:flex;align-items:center;
  justify-content:center;background:#1b2130;color:#54658a;font-size:26px;font-weight:600;border-radius:var(--radius)}
.card .dur{position:absolute;left:7px;bottom:7px;background:rgba(0,0,0,.72);color:#fff;font-size:12px;
  padding:2px 7px;border-radius:5px}
.more-wrap{text-align:center;padding:24px 0 46px}
.btn.big{padding:13px 34px;font-size:17px}
.hint-line{color:var(--fg2);font-size:15px}

/* 详情 */
.detail{display:flex;gap:38px;padding-top:10px}
.detail-poster{flex:0 0 250px}
.detail-poster .ph{width:250px;height:333px;border-radius:13px;background:#1b2333 center/cover no-repeat;
  box-shadow:0 14px 40px rgba(0,0,0,.6)}
.detail-main{flex:1;min-width:0}
.detail-title{font-size:34px;font-weight:700;margin:2px 0 14px;line-height:1.22}
.detail-meta{display:flex;gap:12px;flex-wrap:wrap;margin-bottom:16px}
.detail-meta span{font-size:15.5px;color:var(--fg2);background:var(--card);padding:5px 14px;border-radius:6px}
.detail-meta span.hl{color:var(--accent2)}
.detail-actions{display:flex;gap:14px;margin:20px 0 22px}
.detail-act{padding:13px 32px;border-radius:9px;font-size:18px;font-weight:600;cursor:pointer;
  border:2px solid transparent;background:var(--accent);color:#06111f;transition:.18s}
.detail-act.ghost{background:var(--card);color:var(--fg);border-color:var(--line)}
.detail-act.focused,.detail-act:focus{transform:scale(1.06);box-shadow:0 0 0 3px #fff}
.detail-desc{font-size:16px;line-height:1.85;color:#bdc9e0;max-height:170px;overflow-y:auto;
  border-left:2px solid var(--line);padding-left:16px}
.detail-desc::-webkit-scrollbar{width:6px}
.detail-desc::-webkit-scrollbar-thumb{background:#2a3550;border-radius:3px}
.ep-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(120px,1fr));gap:11px;margin-top:14px}
.ep{padding:11px 8px;background:var(--card);border:2px solid var(--line);border-radius:7px;font-size:15px;
  text-align:center;cursor:pointer;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;transition:.15s}
.ep.on{background:rgba(62,166,255,.16);border-color:var(--accent);color:var(--accent)}
.ep.focused,.ep:focus{background:var(--accent);color:#06111f;border-color:#fff;transform:scale(1.06)}

/* 搜索键盘 */
.search-box{display:flex;align-items:center;gap:14px;margin-bottom:20px}
#searchInput{flex:0 0 460px;height:56px;background:var(--card);border:2px solid var(--line);border-radius:9px;
  color:var(--fg);font-size:22px;padding:0 20px;outline:none;letter-spacing:2px}
#searchInput:focus{border-color:var(--accent)}
.kbd{display:grid;grid-template-columns:repeat(13,1fr);gap:9px;max-width:960px;margin-bottom:24px}
.key{height:50px;display:flex;align-items:center;justify-content:center;background:var(--card);
  border:2px solid var(--line);border-radius:7px;font-size:19px;cursor:pointer;transition:.15s}
.key.focused,.key:focus{background:var(--accent);color:#06111f;border-color:#fff;transform:scale(1.07)}

/* 直播 */
.live-wrap{display:flex;gap:28px}
.live-side{flex:0 0 220px;max-height:calc(100vh - 230px);overflow-y:auto;border-right:1px solid var(--line);padding-right:14px}
.live-main{flex:1}
.grp{padding:11px 15px;border-radius:8px;font-size:16.5px;color:var(--fg2);cursor:pointer;outline:none;
  margin-bottom:6px;transition:.15s;border:2px solid transparent}
.grp.on{background:rgba(62,166,255,.16);color:var(--accent)}
.grp.focused,.grp:focus{background:var(--accent);color:#06111f;border-color:#fff}
.live-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(200px,1fr));gap:12px}
.ch{padding:13px 15px;background:var(--card);border:2px solid var(--line);border-radius:9px;font-size:15.5px;
  cursor:pointer;outline:none;transition:.15s;display:flex;align-items:center;gap:11px;overflow:hidden}
.ch img{width:32px;height:32px;object-fit:contain;flex:0 0 32px;border-radius:5px;background:#0e1320}
.ch span{overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.ch.focused,.ch:focus{background:var(--accent);color:#06111f;border-color:#fff;transform:scale(1.04)}

/* 播放器 */
.hidden{display:none !important}
#playerLayer{position:fixed;top:0;right:0;bottom:0;left:0;background:#000;z-index:200;display:flex;flex-direction:column}
#video{width:100%;height:100%;background:#000;object-fit:contain}
#playerHud{position:absolute;left:0;right:0;bottom:0;padding:24px 44px 28px;transition:opacity .4s;
  background:linear-gradient(0deg,rgba(0,0,0,.92),transparent)}
#playerHud.hide{opacity:0;pointer-events:none}
.ptitle{font-size:24px;margin-bottom:13px}
.pbar{display:flex;align-items:center;gap:18px;margin-bottom:14px}
.pbtn{background:rgba(255,255,255,.12);border:2px solid rgba(255,255,255,.25);color:#fff;padding:9px 21px;
  border-radius:8px;font-size:16.5px;cursor:pointer;transition:.15s}
.pbtn.focused,.pbtn:focus{background:var(--accent);color:#06111f;border-color:#fff}
.pinfo{font-size:14.5px;color:#9fb0cc}
.epbar{display:flex;gap:10px;overflow-x:auto;padding-bottom:6px}
.epbar::-webkit-scrollbar{height:0}
.epbar .ep{flex:0 0 auto;min-width:100px;padding:9px 14px}
.ptip{position:absolute;top:50%;left:50%;transform:translate(-50%,-50%);background:rgba(0,0,0,.78);
  padding:18px 34px;border-radius:10px;font-size:19px;max-width:70%;text-align:center}

/* 教材阅读器 */
#reader{position:fixed;top:0;right:0;bottom:0;left:0;background:#05070c;z-index:180;display:flex;flex-direction:column}
.rd-top{display:flex;align-items:center;gap:20px;padding:16px 34px;border-bottom:1px solid var(--line)}
.rd-title{font-size:20px;flex:1;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.rd-page{font-size:17px;color:var(--fg2);font-variant-numeric:tabular-nums}
.rd-btn{background:var(--card);border:2px solid var(--line);color:var(--fg);padding:9px 20px;
  border-radius:8px;font-size:16px;cursor:pointer;transition:.15s}
.rd-btn.focused,.rd-btn:focus{background:var(--accent);color:#06111f;border-color:#fff}
.rd-body{flex:1;display:flex;align-items:center;justify-content:center;gap:18px;padding:16px;overflow:hidden}
#rdImg{max-width:100%;max-height:100%;object-fit:contain;border-radius:6px;background:#0d1119;
  box-shadow:0 12px 40px rgba(0,0,0,.8);transition:transform .25s}
#rdImg.zoom{transform:scale(1.6);cursor:move}
.rd-nav{width:64px;height:130px;flex:0 0 64px;background:rgba(255,255,255,.07);border:2px solid var(--line);
  color:#fff;font-size:40px;line-height:1;border-radius:10px;cursor:pointer;transition:.15s}
.rd-nav.focused,.rd-nav:focus{background:var(--accent);color:#06111f;border-color:#fff;transform:scale(1.06)}
.rd-thumbs{display:flex;gap:9px;overflow-x:auto;padding:14px 34px;border-top:1px solid var(--line);max-height:130px}
.rd-thumbs::-webkit-scrollbar{height:6px}
.rd-thumbs::-webkit-scrollbar-thumb{background:#2a3550;border-radius:3px}
.rd-thumbs img{height:86px;border-radius:5px;border:3px solid transparent;cursor:pointer;flex:0 0 auto;background:#1b2333}
.rd-thumbs img.on{border-color:var(--accent)}
.rd-thumbs img.focused,.rd-thumbs img:focus{border-color:#fff;transform:scale(1.06)}

.toast{position:fixed;bottom:54px;left:50%;transform:translateX(-50%) translateY(24px);background:rgba(20,26,40,.97);
  border:1px solid var(--line);color:#fff;padding:14px 30px;border-radius:9px;font-size:17.5px;opacity:0;
  transition:.3s;z-index:300;pointer-events:none;max-width:70%}
.toast.on{opacity:1;transform:translateX(-50%) translateY(0)}
.hint{position:fixed;right:26px;bottom:14px;font-size:13px;color:#3d4a66;z-index:40}

/* ==========================================================================
 * flex-gap 兜底
 * Chromium < 84 不支持 flex 容器的 gap 属性（会被静默忽略），
 * 表现是卡片/胶囊/按钮全部贴在一起、没有间距。
 * 由 app.js 运行时探测后给 <html> 加 .no-flexgap，这里用 margin 补上间距。
 * 注意：grid 容器的 gap 从 Chromium 57 起就支持，不受影响。
 * ========================================================================== */
.no-flexgap .brand .dot{margin-right:9px}
.no-flexgap .nav-item{margin-right:8px}
.no-flexgap .chips > *{margin-right:11px;margin-bottom:11px}
.no-flexgap .chips .label{margin-right:14px}
.no-flexgap .row-track > *{margin-right:16px}
.no-flexgap .section-t::before{margin-right:12px}
.no-flexgap .detail-poster{margin-right:38px}
.no-flexgap .detail-meta > *{margin-right:12px}
.no-flexgap .detail-actions > *{margin-right:14px}
.no-flexgap .search-box > *{margin-right:14px}
.no-flexgap .pbar > *{margin-right:18px}
.no-flexgap .epbar > *{margin-right:10px}
.no-flexgap .live-side{margin-right:28px}
.no-flexgap .ch img{margin-right:11px}
.no-flexgap .rd-top > *{margin-right:20px}
.no-flexgap .rd-body > *{margin-right:18px}
.no-flexgap .rd-thumbs img{margin-right:9px}