:root{
  --blue:#2f7de1; --orange:#e8743b; --green:#39a275;
  --ink:#1f2733; --sub:#5b6b7e; --line:#e6ecf3; --bg:#f5f8fc;
  --card:#ffffff; --shadow:0 6px 24px rgba(31,39,51,.08);
}

/* ---------- 高级分栏布局：侧边导航 + 主内容 ---------- */
.app-shell{display:flex;min-height:100vh;background:
  radial-gradient(900px 420px at 100% 0,rgba(47,125,225,.05),transparent),
  radial-gradient(800px 380px at 0 100%,rgba(57,162,117,.05),transparent),
  var(--bg);}
.sidebar{
  width:266px;flex:0 0 266px;position:sticky;top:0;align-self:flex-start;
  height:100vh;overflow-y:auto;background:rgba(255,255,255,.92);
  backdrop-filter:blur(10px);border-right:1px solid var(--line);
  padding:18px 16px;display:flex;flex-direction:column;gap:14px;z-index:20;
}
.sidebar .brand{display:flex;align-items:center;gap:12px;position:relative}
.sidebar .brand .logo{width:42px;height:42px;border-radius:12px;display:grid;place-items:center;font-size:24px;font-weight:800;color:#fff;background:linear-gradient(135deg,var(--blue),#6aa6f5);box-shadow:0 6px 16px rgba(47,125,225,.35)}
.sidebar .brand-title{font-weight:800;font-size:16px;line-height:1.2}
.sidebar .brand-sub{font-size:11.5px;color:var(--sub)}
.menu-toggle{display:none;margin-left:auto;border:1px solid var(--line);background:#fff;border-radius:10px;width:38px;height:38px;font-size:18px;cursor:pointer;color:var(--sub)}
.sidebar .search-wrap{width:100%}
#search{width:100%;padding:10px 12px;border:1px solid var(--line);border-radius:11px;font-size:13px;outline:none;background:#fff;transition:.18s}
#search:focus{border-color:var(--blue);box-shadow:0 0 0 3px rgba(47,125,225,.12)}
.side-nav{display:flex;flex-direction:column;gap:8px}
.side-nav .tab{
  display:flex;align-items:center;justify-content:space-between;width:100%;
  border:1px solid var(--line);background:#fff;color:var(--ink);
  padding:12px 14px;border-radius:12px;cursor:pointer;font-size:14px;font-weight:700;transition:.18s;
}
.side-nav .tab em{font-style:normal;font-size:11px;background:var(--bg);padding:2px 8px;border-radius:8px;color:var(--sub)}
.side-nav .tab:hover{border-color:#cdd9e6;transform:translateX(2px)}
.side-nav .tab.active{color:#fff;border-color:transparent;box-shadow:var(--shadow);transform:none}
.side-nav .tab.active[data-cat=geometric]{background:linear-gradient(135deg,var(--blue),#5b9bf0)}
.side-nav .tab.active[data-cat=algorithm]{background:linear-gradient(135deg,var(--orange),#f0955f)}
.side-nav .tab.active[data-cat=memory]{background:linear-gradient(135deg,var(--green),#54bd92)}
.side-nav .tab.active em{background:rgba(255,255,255,.25);color:#fff}
.side-sep{height:1px;background:var(--line);margin:2px 0}
.side-group{display:flex;flex-direction:column;gap:3px}
.side-group-t{font-size:11px;text-transform:uppercase;letter-spacing:.7px;color:#9aa9bb;padding:6px 8px 2px;font-weight:800}
.side-link{
  display:flex;align-items:center;gap:10px;width:100%;text-align:left;
  border:none;background:transparent;color:var(--ink);padding:10px 10px;border-radius:10px;
  cursor:pointer;font-size:13.5px;transition:.16s;font-weight:500;
}
.side-link:hover{background:var(--bg);color:var(--blue)}
.side-bottom{margin-top:auto;display:flex;flex-direction:column;gap:8px;padding-top:12px;border-top:1px solid var(--line)}
.side-bottom .auth{display:flex}
.side-bottom .auth .btn.ghost{width:100%;justify-content:center}
.user-dd{width:100%}
.user-btn{width:100%}

/* 主内容 */
.main{flex:1;min-width:0;display:flex;flex-direction:column}
.hero-cta .btn.ghost{background:#22324a;color:#e8f0fb}
.hero-cta .btn.ghost:hover{filter:brightness(1.15)}

/* 详情弹层中的「打开互动游戏 / 课件」按钮 */
.embed-open{
  display:inline-flex;align-items:center;gap:6px;margin-top:10px;
  background:linear-gradient(135deg,var(--blue),#6aa6f5);color:#fff;border:none;
  padding:9px 16px;border-radius:12px;font-size:14px;font-weight:700;cursor:pointer;
  box-shadow:0 6px 16px rgba(47,125,225,.3);transition:.18s;
}
.embed-open:hover{filter:brightness(1.06);transform:translateY(-1px)}
.embed-open[hidden]{display:none}
.embed-modal{max-width:1120px;padding:0}
.embed-head{padding:16px 22px;border-bottom:1px solid var(--line);font-weight:800;font-size:16px;color:var(--ink)}
.embed-stage{height:72vh;background:#0f1726}
.embed-frame{width:100%;height:100%;border:none;background:#fff;display:block}

/* 后台编辑：嵌入资源字段 */
.mk-embed{background:var(--bg);border:1px solid var(--line);border-radius:12px;padding:14px;display:flex;flex-direction:column;gap:10px}
.mk-embed-d{font-size:13px;color:var(--sub);line-height:1.6}
.mk-embed input[type=file]{font-size:13px;max-width:100%}
.mk-embed-info{font-size:13px;color:#27406b}
.mk-embed-cl{font-size:13px;color:var(--sub);display:flex;align-items:center;gap:6px}

/* 移动端：侧边栏改为抽屉 */
@media (max-width:860px){
  .sidebar{position:fixed;left:0;top:0;bottom:0;z-index:60;transform:translateX(-100%);transition:transform .25s ease;box-shadow:0 0 50px rgba(0,0,0,.22)}
  body.sidebar-open .sidebar{transform:none}
  .menu-toggle{display:block}
  .app-shell{display:block}
  .hero-inner{padding:34px 18px 28px}
  .hero h1{font-size:30px}
}
*{box-sizing:border-box;margin:0;padding:0}
html,body{height:100%}
body{
  font-family:"PingFang SC","Microsoft YaHei","Segoe UI",system-ui,sans-serif;
  background:var(--bg); color:var(--ink); line-height:1.6;
}
/* ---------- topbar ---------- */
.topbar{
  position:sticky;top:0;z-index:30;background:rgba(255,255,255,.92);
  backdrop-filter:blur(8px);border-bottom:1px solid var(--line);
  display:flex;align-items:center;gap:18px;padding:10px 22px;flex-wrap:wrap;
}
.brand{display:flex;align-items:center;gap:12px}
.logo{
  width:40px;height:40px;border-radius:11px;display:grid;place-items:center;
  font-size:24px;font-weight:700;color:#fff;
  background:linear-gradient(135deg,var(--blue),#6aa6f5);
  box-shadow:0 4px 14px rgba(47,125,225,.35);
}
.brand-title{font-weight:700;font-size:17px}
.brand-sub{font-size:12px;color:var(--sub)}
.tabs{display:flex;gap:8px;margin-left:auto}
.tab{
  border:1px solid var(--line);background:#fff;color:var(--sub);
  padding:8px 14px;border-radius:10px;cursor:pointer;font-size:14px;
  transition:.18s;font-weight:600;display:flex;align-items:center;gap:6px;
}
.tab em{font-style:normal;font-size:11px;background:var(--bg);padding:1px 7px;border-radius:8px;color:var(--sub)}
.tab:hover{border-color:#cdd9e6}
.tab.active{color:#fff;border-color:transparent;box-shadow:var(--shadow)}
.tab.active[data-cat=geometric]{background:var(--blue)}
.tab.active[data-cat=algorithm]{background:var(--orange)}
.tab.active[data-cat=memory]{background:var(--green)}
.tab.active em{background:rgba(255,255,255,.25);color:#fff}
.search-wrap{width:200px}
#search{
  width:100%;padding:9px 12px;border:1px solid var(--line);border-radius:10px;
  font-size:13px;outline:none;background:#fff;transition:.18s;
}
#search:focus{border-color:var(--blue);box-shadow:0 0 0 3px rgba(47,125,225,.12)}

/* ---------- hero（首页大标题区：双栏 = 文案 + 数学插画） ---------- */
.hero{
  background:
    radial-gradient(1100px 380px at 12% -10%,rgba(47,125,225,.16),transparent),
    radial-gradient(900px 320px at 92% 0%,rgba(57,162,117,.14),transparent),
    linear-gradient(180deg,#fbfdff 0%,#f4f8fc 100%);
  border-bottom:1px solid var(--line);
  position:relative;overflow:hidden;
}
.hero-inner{max-width:1180px;margin:0 auto;padding:56px 22px 44px;position:relative;z-index:1}
.hero-grid{display:grid;grid-template-columns:1.15fr .85fr;gap:36px;align-items:center}
.hero-eyebrow{
  display:inline-block;font-size:13px;font-weight:700;color:var(--blue);
  background:rgba(47,125,225,.08);border:1px solid rgba(47,125,225,.22);
  padding:5px 14px;border-radius:30px;letter-spacing:1px;margin-bottom:18px;
}
.hero h1{
  font-size:46px;line-height:1.22;font-weight:900;letter-spacing:1px;
  background:linear-gradient(120deg,#16283f 30%,#2b4a72 100%);
  -webkit-background-clip:text;background-clip:text;color:transparent;
}
.hero .hl{
  background:linear-gradient(90deg,var(--blue),#5b9bf0);
  -webkit-background-clip:text;background-clip:text;color:transparent;
}
.hero .hl2{
  font-size:.82em;letter-spacing:2px;
  background:linear-gradient(90deg,#e8743b 0%,var(--blue) 45%,var(--green) 100%);
  -webkit-background-clip:text;background-clip:text;color:transparent;
}
.hero p{max-width:640px;margin-top:16px;color:var(--sub);font-size:15.5px;line-height:1.75}
.hero p b{color:var(--ink)}
.hero-art svg{width:100%;height:auto;display:block;filter:drop-shadow(0 18px 40px rgba(31,39,51,.10))}
.hf{animation:hfloat 5.2s ease-in-out infinite}
.hf2{animation-delay:-1.3s}
.hf3{animation-delay:-2.6s}
.hf4{animation-delay:-3.9s}
@keyframes hfloat{
  0%,100%{transform:translateY(0)}
  50%{transform:translateY(-9px)}
}
@media (prefers-reduced-motion:reduce){.hf{animation:none}}
.hero-stats{display:flex;gap:14px;margin-top:30px;flex-wrap:wrap}
.stat{
  background:#fff;border:1px solid var(--line);border-radius:14px;
  padding:14px 18px;min-width:150px;box-shadow:var(--shadow);
}
.stat .n{font-size:26px;font-weight:800}
.stat .l{font-size:13px;color:var(--sub);margin-top:2px}
.stat.b .n{color:var(--blue)} .stat.o .n{color:var(--orange)} .stat.g .n{color:var(--green)}
@media (max-width:960px){
  .hero-grid{grid-template-columns:1fr;gap:20px}
  .hero-art{max-width:440px;margin:0 auto}
  .hero h1{font-size:36px}
}

/* ---------- grid ---------- */
.grid{
  max-width:1180px;margin:0 auto;padding:30px 22px 60px;
  display:grid;grid-template-columns:repeat(auto-fill,minmax(252px,1fr));gap:18px;
}
.card{
  background:var(--card);border:1px solid var(--line);border-radius:16px;
  padding:18px;cursor:pointer;transition:.2s;position:relative;overflow:hidden;
  box-shadow:0 2px 8px rgba(31,39,51,.04);
}
.card:hover{transform:translateY(-4px);box-shadow:var(--shadow);border-color:transparent}
.card::before{content:"";position:absolute;left:0;top:0;height:100%;width:4px;background:var(--blue)}
.card.g::before{background:var(--blue)}
.card.a::before{background:var(--orange)}
.card.m::before{background:var(--green)}
.card .num{font-size:12px;color:var(--sub);font-variant-numeric:tabular-nums}
.card .ct{font-size:17px;font-weight:700;margin:6px 0 8px}
.card .sum{font-size:13px;color:var(--sub);min-height:40px}
.card .tags{display:flex;flex-wrap:wrap;gap:6px;margin-top:12px}
.tag{font-size:11px;background:var(--bg);color:var(--sub);padding:2px 9px;border-radius:20px;border:1px solid var(--line)}
.card .go{position:absolute;right:16px;bottom:14px;font-size:13px;color:var(--blue);opacity:0;transition:.2s}
.card:hover .go{opacity:1}

/* ---------- overlay / modal ---------- */
.overlay{
  position:fixed;inset:0;background:rgba(18,26,38,.5);backdrop-filter:blur(3px);
  z-index:50;display:flex;align-items:center;justify-content:center;padding:24px;
}
.overlay[hidden]{display:none}
.modal{
  background:#fff;border-radius:20px;max-width:1040px;width:100%;max-height:90vh;
  overflow:auto;box-shadow:0 30px 80px rgba(0,0,0,.3);position:relative;
}
.close{
  position:absolute;right:16px;top:14px;width:34px;height:34px;border-radius:10px;
  border:1px solid var(--line);background:#fff;font-size:22px;line-height:1;cursor:pointer;color:var(--sub);
}
.close:hover{background:var(--bg)}
.modal-head{padding:22px 26px 14px;border-bottom:1px solid var(--line)}
.modal-head h2{font-size:22px;margin:8px 0 6px}
.badge{display:inline-block;font-size:12px;font-weight:700;color:#fff;padding:3px 11px;border-radius:20px}
.badge.g{background:var(--blue)} .badge.a{background:var(--orange)} .badge.m{background:var(--green)}
.modal-head .tags{margin-top:4px}
.modal-body{display:grid;grid-template-columns:1.15fr .85fr;gap:0}
.modal-body.three-col{grid-template-columns:1.05fr .95fr .85fr}
.viz-pane{background:#0f1726;padding:20px;min-height:440px;display:flex;flex-direction:column}
.info-pane{padding:22px 24px}

/* 过程算法型：中部「推导与计算过程」面板 */
.steps-pane{padding:22px 22px;background:#fbfdff;border-left:1px solid var(--line);border-right:1px solid var(--line);
  max-height:90vh;overflow:auto;display:flex;flex-direction:column}
.steps-head{font-size:17px;font-weight:800;color:var(--orange)}
.steps-sub{font-size:12.5px;color:var(--sub);margin-top:4px;margin-bottom:14px}
.steps-list{display:flex;flex-direction:column;gap:10px}
.step-item{display:flex;gap:12px;align-items:flex-start;background:#fff;border:1px solid var(--line);
  border-radius:12px;padding:12px 14px;transition:.18s}
.step-item.cur{border-color:var(--orange);box-shadow:0 4px 16px rgba(232,116,59,.16)}
.step-num{flex-shrink:0;width:26px;height:26px;border-radius:50%;background:var(--orange);color:#fff;
  display:grid;place-items:center;font-size:13px;font-weight:700}
.step-txt{flex:1;font-size:14.5px;line-height:1.7;color:#27313d}
.step-txt .katex{color:#1f2733}
.steps-prog{font-size:12.5px;color:var(--sub);margin-top:12px;font-weight:600}
.formula-box{
  background:linear-gradient(135deg,#f3f8ff,#eefbf4);border:1px solid var(--line);
  border-radius:14px;padding:16px 18px;font-size:17px;text-align:center;overflow-x:auto;
}
.explain{margin-top:18px;color:#33414f;font-size:14.5px}
.explain p{margin-bottom:10px}
.viz-title{color:#cdd9e6;font-size:13px;margin-bottom:10px;letter-spacing:.5px}
.viz-canvas-wrap{position:relative;flex:1;display:flex;align-items:center;justify-content:center}
canvas{display:block;max-width:100%;border-radius:12px;background:#0b1220}
.controls{margin-top:14px;display:flex;flex-direction:column;gap:10px}
.ctrl-row{display:flex;align-items:center;gap:10px;color:#cdd9e6;font-size:13px}
.ctrl-row label{min-width:84px}
input[type=range]{flex:1;accent-color:var(--blue)}
.btn{
  background:var(--blue);color:#fff;border:none;padding:9px 16px;border-radius:10px;
  cursor:pointer;font-size:14px;font-weight:600;transition:.18s;
}
.btn:hover{filter:brightness(1.07)}
.btn.ghost{background:#22324a;color:#cdd9e6}
.btn-row{display:flex;gap:10px;flex-wrap:wrap}
.step-box{
  margin-top:14px;background:#13203a;border:1px solid #1f3354;border-radius:12px;
  padding:12px 14px;color:#dbe6f3;font-size:13.5px;min-height:64px;
}
.step-box .kx{color:#7fd1ff;font-weight:700}

/* ---------- memory cards / game ---------- */
.flip-area{display:flex;flex-direction:column;gap:12px;align-items:center;width:100%}
.flashcard{
  width:100%;max-width:360px;height:120px;border-radius:14px;perspective:900px;cursor:pointer;
}
.flashcard .inner{position:relative;width:100%;height:100%;transition:transform .5s;transform-style:preserve-3d}
.flashcard.flip .inner{transform:rotateY(180deg)}
.flashcard .face{
  position:absolute;inset:0;display:grid;place-items:center;backdrop-border:1px solid #1f3354;
  border:1px solid #1f3354;border-radius:14px;background:#13203a;color:#e8f0fb;padding:10px;text-align:center;
}
.flashcard .back{transform:rotateY(180deg);background:#16335a;color:#aee9ff}
.note{color:#9fb3c8;font-size:12px;text-align:center}
.game-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:8px;width:100%}
.gcard{
  background:#13203a;border:1px solid #1f3354;border-radius:10px;padding:8px 6px;text-align:center;
  color:#e8f0fb;font-size:13px;cursor:pointer;min-height:54px;display:grid;place-items:center;transition:.15s;
}
.gcard.sel{background:#1d4ed8;border-color:#3b82f6}
.gcard.done{background:#155e3a;border-color:#22c55e;cursor:default;opacity:.7}
.gcard.wrong{animation:shake .3s}
@keyframes shake{0%,100%{transform:translateX(0)}25%{transform:translateX(-5px)}75%{transform:translateX(5px)}}

.foot{
  border-top:1px solid var(--line);background:#fff;padding:16px 22px;
  display:flex;justify-content:space-between;flex-wrap:wrap;gap:8px;
  color:var(--sub);font-size:13px;
}
.foot .dim{opacity:.7}

@media (max-width:820px){
  .modal-body{grid-template-columns:1fr}
  .viz-pane{min-height:360px}
  .hero h1{font-size:30px}
}

/* ---------- hero CTA ---------- */
.hero-cta{display:flex;gap:12px;margin-top:22px;flex-wrap:wrap}
.hero-cta .btn.ghost{background:#22324a;color:#e8f0fb}
.hero-cta .btn.ghost:hover{filter:brightness(1.15)}

/* ---------- guide (三类认知策略导览图) ---------- */
.guide{background:#fff;border-bottom:1px solid var(--line)}
.guide-inner{max-width:1180px;margin:0 auto;padding:34px 22px 40px}
.guide-title{font-size:22px;font-weight:800}
.guide-sub{color:var(--sub);margin:8px 0 18px;font-size:14.5px}
.guide-svg-wrap{background:linear-gradient(135deg,#f7fbff,#f3fbf6);border:1px solid var(--line);
  border-radius:16px;padding:14px;overflow:auto}
.guide-svg{width:100%;max-width:760px;display:block;margin:0 auto}
.guide-svg .gnode{cursor:pointer;transition:.18s}
.guide-svg .gnode:hover rect{filter:brightness(1.07);transform:translateY(-2px)}
.guide-svg .gnode:hover rect{transform:translateY(-2px)}
.guide-cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:16px;margin-top:18px}
.gcard-cat{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:18px 18px 16px;
  cursor:pointer;transition:.2s;position:relative;overflow:hidden;border-top:4px solid var(--c)}
.gcard-cat:hover{transform:translateY(-4px);box-shadow:var(--shadow)}
.gcard-cat-h{font-size:17px;font-weight:700;display:flex;align-items:center;gap:8px}
.gcard-cat-h em{font-style:normal;font-size:12px;background:var(--bg);padding:1px 8px;border-radius:8px;color:var(--sub)}
.gdot{width:11px;height:11px;border-radius:50%;display:inline-block}
.gcard-cat-d{font-size:13.5px;color:var(--sub);margin:10px 0}
.gcard-cat-t{font-size:12.5px;color:#7a8aa0;background:var(--bg);display:inline-block;padding:4px 10px;border-radius:8px}
.gcard-cat-go{margin-top:12px;font-size:13px;color:var(--blue);font-weight:600}

/* ---------- topbar auth ---------- */
.auth{display:flex;align-items:center}
.auth .btn.ghost{padding:8px 14px}
.user{display:flex;align-items:center;gap:8px;background:#fff;border:1px solid var(--line);
  border-radius:10px;padding:5px 10px}
.user .ava{width:26px;height:26px;border-radius:50%;background:var(--blue);color:#fff;
  display:grid;place-items:center;font-weight:700;font-size:13px}
.user .uname{font-size:14px;font-weight:600;max-width:90px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.user .link{border:none;background:none;color:var(--blue);cursor:pointer;font-size:13px;font-weight:600}
.quiz-btn{background:rgba(47,125,225,.1);color:var(--blue);border-color:transparent}
.quiz-btn:hover{background:rgba(47,125,225,.18)}

/* ---------- auth modal ---------- */
.auth-modal{max-width:420px}
.auth-modal .modal-head{padding-bottom:10px}
.auth-sub{font-size:13px;color:var(--sub);margin-top:4px}
.auth-body{padding:18px 26px 24px}
.seg{display:flex;background:var(--bg);border-radius:12px;padding:4px;margin-bottom:16px}
.seg-btn{flex:1;border:none;background:none;padding:9px;border-radius:9px;cursor:pointer;
  font-size:14px;font-weight:600;color:var(--sub)}
.seg-btn.active{background:#fff;color:var(--ink);box-shadow:var(--shadow)}
.auth-input{width:100%;padding:11px 13px;border:1px solid var(--line);border-radius:10px;
  font-size:14px;margin-bottom:12px;outline:none;transition:.18s}
.auth-input:focus{border-color:var(--blue);box-shadow:0 0 0 3px rgba(47,125,225,.12)}
.auth-remember{display:flex;align-items:center;gap:7px;font-size:12.5px;color:var(--sub);margin:2px 0 4px;cursor:pointer;user-select:none}
.auth-remember input{width:15px;height:15px;accent-color:var(--blue);cursor:pointer}
.auth-msg{min-height:18px;font-size:13px;color:#e8743b;margin-bottom:8px}
.auth-msg.err{color:#e0552f}
.auth-submit{width:100%;padding:11px}
.auth-note{margin-top:14px;font-size:11.5px;color:#9aa9ba;line-height:1.5}

/* ---------- quiz modal ---------- */
.quiz-modal{max-width:720px}
.quiz-inner{padding:22px 26px 28px}
.quiz-head h2{font-size:22px}
.quiz-desc{color:var(--sub);font-size:14px;margin-top:6px}
.quiz-start .field{margin:18px 0}
.field-label{font-size:13px;font-weight:700;color:var(--ink);margin-bottom:8px}
.opts{display:flex;flex-wrap:wrap;gap:10px}
.opt{display:flex;align-items:center;gap:6px;background:var(--bg);border:1px solid var(--line);
  border-radius:10px;padding:8px 13px;font-size:14px;cursor:pointer}
.opt em{font-style:normal;font-size:11px;background:#fff;padding:1px 7px;border-radius:7px;color:var(--sub)}
.dash{margin-top:20px;background:var(--bg);border:1px solid var(--line);border-radius:14px;padding:16px 18px}
.dash-who{font-size:13.5px;color:var(--sub);margin-bottom:12px}
.dash-row{margin-bottom:12px}
.dash-top{display:flex;justify-content:space-between;font-size:13px;margin-bottom:5px}
.bar{height:10px;background:#e3e9f1;border-radius:6px;overflow:hidden}
.bar i{display:block;height:100%;border-radius:6px;transition:width .4s}
.quiz-progress{font-size:13px;color:var(--sub);font-weight:600;margin-bottom:10px}
.q-prompt{font-size:17px;font-weight:700}
.q-sum{font-size:14px;color:var(--sub);margin:8px 0 16px}
.q-opts{display:grid;grid-template-columns:1fr 1fr;gap:12px}
.qopt{background:#f7faff;border:1.5px solid var(--line);border-radius:12px;padding:16px 12px;
  cursor:pointer;font-size:16px;transition:.15s;min-height:64px;display:flex;align-items:center;justify-content:center}
.qopt:hover{border-color:var(--blue);background:#eef5ff}
.qopt.right{background:#e7f8ee;border-color:#22c55e;color:#0f7a3d}
.qopt.wrong{background:#fdecec;border-color:#ef4444;color:#b91c1c}
.qopt:disabled{cursor:default}
.q-fb{margin-top:16px;font-size:14.5px;font-weight:600}
.q-fb.ok{color:#0f7a3d}.q-fb.no{color:#c0392b}
.q-exp{font-weight:400;color:var(--sub);margin-top:6px;font-size:13.5px}
.res-score{display:flex;align-items:baseline;gap:14px;margin:14px 0 18px}
.rs-num{font-size:38px;font-weight:800;color:var(--blue)}
.rs-pct{font-size:15px;color:var(--sub)}
.res-list{display:flex;flex-direction:column;gap:8px;max-height:300px;overflow:auto;margin-bottom:8px}
.res-item{display:flex;align-items:center;gap:10px;background:var(--bg);border:1px solid var(--line);
  border-radius:10px;padding:9px 13px;font-size:14px}
.res-item .dot{width:9px;height:9px;border-radius:50%}
.res-item.ok .dot{background:#22c55e}.res-item.no .dot{background:#ef4444}
.res-name{flex:1}
.res-tag{font-size:12px;font-weight:700}
.res-item.ok .res-tag{color:#0f7a3d}.res-item.no .res-tag{color:#c0392b}

@media (max-width:820px){
  .q-opts{grid-template-columns:1fr}
  .guide-svg{width:680px}
}

/* ---------- 登录门禁 ---------- */
body.locked .app-shell{display:none !important}
.login-screen{display:none}
body.locked .login-screen{
  display:flex;position:fixed;inset:0;z-index:200;align-items:center;justify-content:center;
  background:linear-gradient(135deg,#0f1726,#15233b);padding:24px;overflow:auto;
}
.login-card{background:#fff;border-radius:20px;max-width:440px;width:100%;padding:34px 32px;box-shadow:0 30px 80px rgba(0,0,0,.35)}
.login-logo{width:54px;height:54px;border-radius:14px;display:grid;place-items:center;font-size:30px;font-weight:700;color:#fff;
  background:linear-gradient(135deg,var(--blue),#6aa6f5);box-shadow:0 6px 18px rgba(47,125,225,.35);margin-bottom:14px}
.login-title{font-size:22px;font-weight:800}
.login-sub{font-size:13px;color:var(--sub);margin-top:4px}
.login-h2{font-size:20px;margin-top:20px}
.login-tip{font-size:14px;color:var(--sub);margin:8px 0 18px;line-height:1.6}
.login-tip b{color:var(--blue)}
.login-note{margin-top:14px;font-size:11.5px;color:#9aa9ba;line-height:1.5}

/* ---------- 知识图谱（二级展开） ---------- */
.kg-section{margin-top:26px;border-top:1px dashed var(--line);padding-top:22px}
.kg-toggle{border:1px solid var(--line);background:#fff;color:var(--ink);font-size:15px;font-weight:700;
  padding:12px 18px;border-radius:12px;cursor:pointer;width:100%;text-align:left;transition:.18s}
.kg-toggle:hover{border-color:var(--blue);color:var(--blue)}
.kg-toggle.open{background:linear-gradient(135deg,#f3f8ff,#eefbf4)}
.kg-wrap{margin-top:16px}
.kg-tabs{display:flex;gap:10px;margin-bottom:14px;flex-wrap:wrap}
.kg-tab{border:1px solid var(--line);background:#fff;color:var(--sub);padding:8px 16px;border-radius:10px;
  cursor:pointer;font-size:14px;font-weight:600;display:flex;align-items:center;gap:6px}
.kg-tab em{font-style:normal;font-size:11px;background:var(--bg);padding:1px 7px;border-radius:8px;color:var(--sub)}
.kg-tab.active{color:#fff;border-color:transparent}
.kg-tab.active[data-cat=geometric]{background:var(--blue)}
.kg-tab.active[data-cat=algorithm]{background:var(--orange)}
.kg-tab.active[data-cat=memory]{background:var(--green)}
.kg-body{display:grid;grid-template-columns:1.3fr .7fr;gap:16px;align-items:start}
.kg-svg{background:linear-gradient(135deg,#f7fbff,#f3fbf6);border:1px solid var(--line);border-radius:16px;padding:10px;overflow:auto}
.kg-svg-el{width:100%;max-width:760px;display:block;margin:0 auto}
.kgnode:hover circle{filter:brightness(1.18)}
.kg-legend{max-height:480px;overflow:auto;background:#fff;border:1px solid var(--line);border-radius:16px;padding:12px}
.kg-legend-title{font-size:13px;color:var(--sub);margin-bottom:10px;padding-bottom:8px;border-bottom:1px solid var(--line)}
.kg-leg{display:flex;align-items:center;gap:10px;padding:7px 8px;border-radius:9px;cursor:pointer;transition:.15s}
.kg-leg:hover{background:var(--bg)}
.kg-leg-n{width:22px;height:22px;border-radius:50%;color:#fff;display:grid;place-items:center;font-size:12px;font-weight:700;flex-shrink:0}
.kg-leg-t{font-size:13.5px;font-weight:600;flex:1}
.kg-leg-tags{display:flex;gap:4px;flex-wrap:wrap}
.kg-tag{font-size:10.5px;background:var(--bg);color:var(--sub);padding:1px 7px;border-radius:20px}

/* 知识图谱：视图切换（类型图谱 / 按标签聚类） */
.kg-view{display:flex;gap:10px;margin-bottom:14px;flex-wrap:wrap}
.kg-view-tab{border:1px solid var(--line);background:#fff;color:var(--sub);padding:8px 16px;border-radius:10px;
  cursor:pointer;font-size:14px;font-weight:600;transition:.15s}
.kg-view-tab:hover{border-color:var(--blue)}
.kg-view-tab.active{background:#15233b;color:#fff;border-color:transparent}
.kg-leg-group{margin-bottom:8px}
.kg-leg-taghead{display:flex;align-items:center;gap:8px;padding:6px 8px;border-radius:9px;font-weight:700;font-size:13.5px}
.kg-leg-taghead:hover{background:var(--bg)}
.kg-cluster:hover rect{filter:brightness(1.05)}

/* 随机练习 */
.practice-score{font-size:14px;font-weight:700;color:var(--orange);margin:6px 0 16px}

/* ---------- 几何直观型：交互动画 / GeoGebra 切换 ---------- */
.geo-tabs{display:flex;gap:8px;margin-bottom:14px}
.geo-tab{border:1px solid #1f3354;background:#13203a;color:#cdd9e6;padding:8px 16px;border-radius:10px;
  cursor:pointer;font-size:14px;font-weight:600;transition:.15s}
.geo-tab:hover{border-color:#3b82f6}
.geo-tab.active{background:var(--blue);color:#fff;border-color:transparent}

/* ---------- GeoGebra 上传端口 ---------- */
.ggb-wrap{width:100%;display:flex;flex-direction:column;gap:12px}
.ggb-drop{border:2px dashed #2c3e5c;background:#0b1220;border-radius:14px;padding:22px;text-align:center;cursor:pointer;transition:.18s}
.ggb-drop:hover{border-color:#3b82f6;background:#10203a}
.ggb-drop.over{border-color:#5fd6a0;background:#10203a}
.ggb-drop-i{font-size:15px;font-weight:700;color:#e8f0fb}
.ggb-drop-s{font-size:12.5px;color:#9fb3c8;margin-top:6px;line-height:1.5}
.ggb-stage{width:100%;min-height:120px}
.ggb-stage iframe{border:none;max-width:100%;border-radius:12px}
.card.ggb-upload::before{background:linear-gradient(135deg,#7c3aed,#a855f7)}
.card.ggb-upload .ct{color:#6d28d9}

@media (max-width:820px){
  .modal-body.three-col{grid-template-columns:1fr}
  .steps-pane{border-left:none;border-right:none;border-top:1px solid var(--line)}
  .kg-body{grid-template-columns:1fr}
  .kg-svg-el{width:680px}
}

/* KaTeX 在深色面板中以浅色显示 */
.viz-pane .katex, .step-box .katex, .flashcard .katex, .gcard .katex,
.viz-pane .katex-display, .step-box .katex-display{color:#eaf2ff}
.rawtex{font-family:ui-monospace,Menlo,Consolas,monospace;font-size:.9em;white-space:nowrap;opacity:.9}
.flashcard .face .rawtex{font-size:.85em}

/* ==========================================================================
 * 下拉菜单（学习工具 / 用户中心）
 * ========================================================================== */
.dd{position:relative;display:inline-block}
.dd-btn{
  border:1px solid var(--line);background:#fff;color:var(--sub);
  padding:8px 14px;border-radius:10px;cursor:pointer;font-size:14px;font-weight:600;
  transition:.18s;display:inline-flex;align-items:center;gap:6px;white-space:nowrap;
}
.dd-btn:hover{border-color:#cdd9e6;color:var(--ink)}
.dd-btn[aria-expanded="true"]{border-color:var(--blue);color:var(--blue);background:rgba(47,125,225,.06)}
.caret{font-size:11px;transition:transform .2s}
.dd-btn[aria-expanded="true"] .caret{transform:rotate(180deg)}
.dd-menu{
  position:absolute;right:0;top:calc(100% + 8px);min-width:212px;z-index:60;
  background:#fff;border:1px solid var(--line);border-radius:14px;
  box-shadow:0 18px 44px rgba(20,30,48,.16);padding:8px;
  animation:ddIn .16s ease-out;
}
.dd-menu[hidden]{display:none}
.dd-menu-right{right:0;left:auto}
@keyframes ddIn{from{opacity:0;transform:translateY(-6px)}to{opacity:1;transform:translateY(0)}}
.dd-menu-title{font-size:11px;color:#9aa9ba;font-weight:700;letter-spacing:.6px;padding:6px 10px}
.dd-item{
  display:flex;flex-direction:column;align-items:flex-start;gap:1px;width:100%;
  border:none;background:none;text-align:left;cursor:pointer;font-family:inherit;
  padding:9px 11px;border-radius:10px;font-size:14px;font-weight:600;color:var(--ink);transition:.15s;
}
.dd-item:hover{background:var(--bg)}
.dd-item .dd-sub{font-size:11.5px;color:var(--sub);font-weight:400}
.dd-item.danger{color:#c0392b}
.dd-item.danger:hover{background:#fdecec}
.dd-sep{height:1px;background:var(--line);margin:6px 4px}
.dd-user-head{font-size:12px;color:var(--sub);padding:6px 11px 8px;border-bottom:1px solid var(--line);margin-bottom:6px}
.user-btn{padding:5px 10px 5px 5px}
.user-btn .ava{width:26px;height:26px;border-radius:50%;background:var(--blue);color:#fff;
  display:grid;place-items:center;font-weight:700;font-size:13px;flex-shrink:0}
.user-btn .uname{font-size:14px;font-weight:600;max-width:88px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}

/* ==========================================================================
 * 过程算法型：例题与练习（三栏下方的整宽区块）
 * ========================================================================== */
.ex-row{grid-column:1 / -1;border-top:1px solid var(--line);background:#fff}
.exercise-block{padding:22px 26px 26px}
.ex-head{display:flex;align-items:center;gap:10px;flex-wrap:wrap;margin-bottom:14px}
.ex-icon{font-size:20px}
.ex-title{font-size:18px;font-weight:800}
.ex-sub{font-size:12.5px;color:var(--sub)}
.ex-tabs{display:flex;gap:8px;margin-bottom:16px;border-bottom:1px solid var(--line);padding-bottom:12px;flex-wrap:wrap}
.ex-tab{border:1px solid var(--line);background:#fff;color:var(--sub);padding:8px 16px;border-radius:10px;
  cursor:pointer;font-size:14px;font-weight:600;transition:.16s}
.ex-tab:hover{border-color:var(--orange);color:var(--orange)}
.ex-tab.active{background:var(--orange);color:#fff;border-color:transparent}
.ex-pane[hidden]{display:none}
.ex-label{display:flex;align-items:center;gap:10px;font-size:13px;font-weight:700;
  color:var(--orange);margin-bottom:8px;flex-wrap:wrap}
.ex-score{font-weight:700;color:var(--sub);background:var(--bg);padding:2px 9px;border-radius:20px;font-size:12px}
.ex-q{background:linear-gradient(135deg,#fff7f2,#fffdfb);border:1px solid #f6ded0;border-radius:14px;
  padding:16px 18px;font-size:16px;margin-bottom:12px;overflow-x:auto}
.ex-q .katex{color:#1f2733}
.ex-sol{margin-top:14px;background:var(--bg);border:1px solid var(--line);border-radius:14px;padding:14px 16px}
.ex-sol-head{font-size:13px;font-weight:800;color:var(--ink);margin-bottom:10px}
.ex-sol-list{display:flex;flex-direction:column;gap:9px}
.ex-sol-item{display:flex;gap:11px;align-items:flex-start}
.ex-sol-num{flex-shrink:0;width:24px;height:24px;border-radius:50%;background:var(--orange);color:#fff;
  display:grid;place-items:center;font-size:12.5px;font-weight:700}
.ex-sol-txt{flex:1;font-size:14.5px;line-height:1.75;color:#27313d}
.ex-sol-txt .katex{color:#1f2733}
.ex-pane .q-prompt{margin-bottom:14px;overflow-x:auto}

/* ==========================================================================
 * 版面整体优化
 * ========================================================================== */
.topbar{box-shadow:0 2px 12px rgba(31,39,51,.05);gap:14px}
/* 分类导航：分段控件样式 */
.seg-nav{background:var(--bg);border:1px solid var(--line);border-radius:12px;padding:4px;gap:4px;margin-left:auto}
.seg-nav .tab{border:none;background:none}
.seg-nav .tab:hover{background:rgba(47,125,225,.08)}
.seg-nav .tab.active{box-shadow:0 3px 10px rgba(31,39,51,.12)}
/* hero 卡片统一、可交互微动效 */
.hero-stats .stat{border-radius:16px;transition:.2s}
.hero-stats .stat:hover{transform:translateY(-3px);box-shadow:0 12px 26px rgba(31,39,51,.12)}
/* 知识点卡片 */
.card{border-radius:18px}
.card:hover{box-shadow:0 14px 34px rgba(31,39,51,.12)}
.card .num{letter-spacing:.3px}
.card .ct{transition:.2s}
.card:hover .ct{color:var(--blue)}
.card .go{font-weight:600}
/* 弹层头部更醒目 */
.modal-head{background:linear-gradient(135deg,#fbfdff,#f7fbff)}
.badge{letter-spacing:.3px}
/* 搜索框 */
.search-wrap{width:220px}
#search{border-radius:11px;padding:10px 13px}

@media (max-width:820px){
  .search-wrap{width:100%;order:5}
  .seg-nav{margin-left:0;width:100%;order:3;overflow-x:auto}
  .dd{order:4}
  .exercise-block{padding:18px 16px 22px}
}


/* ==========================================================================
 * GeoGebra 全屏播放
 * ========================================================================== */
.ggb-fullscreen{
  position:fixed;inset:0;z-index:300;background:#0b1220;
  display:flex;align-items:center;justify-content:center;padding:12px;
  min-height:0 !important;
}
.ggb-fullscreen iframe{border-radius:10px}

/* ==========================================================================
 * 记忆强化型：自制网页游戏上传端口
 * ========================================================================== */
.hg-wrap{width:100%}
.hg-stage{width:100%;min-height:200px}
.hg-frame{
  width:100%;height:540px;border:none;border-radius:12px;background:#fff;
  box-shadow:0 6px 22px rgba(0,0,0,.28);
}
.hg-empty{
  border:1px dashed #2c3e5c;border-radius:12px;background:#0b1220;color:#9fb3c8;
  padding:34px 18px;text-align:center;font-size:13.5px;
}
.hg-fullscreen{
  position:fixed;inset:0;z-index:300;background:#0b1220;padding:10px;
}
.hg-fullscreen .hg-frame{height:100%;box-shadow:none}

/* 练习题题干：统一公式展示框，避免原始源码裸露的观感 */
.ex-pane .q-prompt{
  background:linear-gradient(135deg,#fff7f2,#fffdfb);
  border:1px solid #f6ded0;border-radius:14px;
  padding:18px 20px;font-size:17px;margin-bottom:14px;overflow-x:auto;
}
.ex-pane .q-prompt .katex-display{margin:.4em 0}
.ex-pane .q-prompt .katex{color:#1f2733;font-size:1.06em}
.stem-mixed{line-height:1.9}

/* ==========================================================================
 * 全屏浮层上的常驻工具条（退出全屏 / 重新适配尺寸）
 * ========================================================================== */
.fs-bar{
  position:absolute;top:10px;right:14px;z-index:320;
  display:flex;gap:8px;align-items:center;flex-wrap:wrap;
}
.fs-bar .btn{
  background:rgba(34,50,74,.92);color:#e8f0fb;border:1px solid #35506f;
  box-shadow:0 6px 18px rgba(0,0,0,.35);
}
.fs-bar .btn:hover{filter:brightness(1.18)}
.fs-bar .fs-exit{background:rgba(200,58,42,.94);border-color:#e0552f;color:#fff}

/* ==========================================================================
 * 身份选择（学生 / 教师）
 * ========================================================================== */
.role-pick{display:flex;align-items:center;gap:8px;margin-bottom:12px}
.role-label{font-size:13px;color:var(--sub);font-weight:600}
.role-btn{
  flex:1;border:1px solid var(--line);background:#fff;color:var(--sub);
  padding:8px 10px;border-radius:10px;cursor:pointer;font-size:13.5px;font-weight:600;transition:.16s;
}
.role-btn:hover{border-color:#cdd9e6}
.role-btn.active{background:var(--blue);color:#fff;border-color:transparent;box-shadow:0 3px 10px rgba(47,125,225,.28)}

/* ==========================================================================
 * 每日签到
 * ========================================================================== */
.ck-head h2{font-size:22px}
.ck-stats{display:flex;gap:12px;margin:14px 0 18px;flex-wrap:wrap}
.ck-stat{flex:1;min-width:110px;background:var(--bg);border:1px solid var(--line);border-radius:14px;padding:14px 16px;text-align:center}
.ck-stat .n{font-size:26px;font-weight:800;color:var(--green)}
.ck-stat .l{font-size:12.5px;color:var(--sub);margin-top:2px}
.ck-panel{background:#fff;border:1px solid var(--line);border-radius:14px;padding:16px 18px}
.ck-label{font-size:13px;font-weight:700;color:var(--ink);margin-bottom:8px}
.ck-moods{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:14px}
.ck-mood{
  border:1px solid var(--line);background:#fff;border-radius:12px;padding:8px 12px;cursor:pointer;
  display:flex;flex-direction:column;align-items:center;gap:2px;transition:.16s;min-width:64px;
}
.ck-mood .e{font-size:22px;line-height:1}
.ck-mood .t{font-size:11.5px;color:var(--sub)}
.ck-mood:hover{border-color:var(--green)}
.ck-mood.active{background:rgba(57,162,117,.12);border-color:var(--green)}
.ck-input{width:100%;padding:11px 13px;border:1px solid var(--line);border-radius:10px;font-size:14px;outline:none;transition:.18s}
.ck-input:focus{border-color:var(--green);box-shadow:0 0 0 3px rgba(57,162,117,.12)}
.ck-msg{min-height:20px;font-size:13.5px;margin-top:10px}
.ck-msg.ok{color:#0f7a3d;font-weight:600}
.ck-msg.warn{color:#c0392b;font-weight:600}
.ck-cal{margin-top:18px;background:#fff;border:1px solid var(--line);border-radius:14px;padding:14px 16px}
.ck-cal-head{display:flex;align-items:center;justify-content:center;gap:14px;margin-bottom:10px}
.ck-nav{border:1px solid var(--line);background:#fff;border-radius:8px;width:30px;height:30px;cursor:pointer;font-size:16px;color:var(--sub)}
.ck-nav:hover{border-color:var(--green);color:var(--green)}
.ck-month{font-size:15px;font-weight:700}
.ck-dow,.ck-grid{display:grid;grid-template-columns:repeat(7,1fr);gap:4px}
.ck-dow span{text-align:center;font-size:11.5px;color:var(--sub);padding:2px 0}
.ck-cell{
  aspect-ratio:1/1;border:1px solid var(--line);border-radius:9px;display:flex;
  flex-direction:column;align-items:center;justify-content:center;gap:1px;background:#fff;
}
.ck-cell.empty{border:none;background:none}
.ck-cell .d{font-size:12.5px;color:var(--sub)}
.ck-cell .m{font-size:14px}
.ck-cell.signed{background:rgba(57,162,117,.14);border-color:#bfe6cf}
.ck-cell.signed .d{color:#0f7a3d;font-weight:700}
.ck-cell.today{outline:2px solid var(--green);outline-offset:-2px}
.ck-legend{font-size:11.5px;color:#9aa9ba;margin-top:10px;text-align:center}

/* ==========================================================================
 * 教师：学习统计
 * ========================================================================== */
.stats-modal{max-width:940px}
.st-overview{display:flex;gap:12px;flex-wrap:wrap;margin:14px 0 20px}
.st-card{flex:1;min-width:120px;background:var(--bg);border:1px solid var(--line);border-radius:14px;padding:14px 16px;text-align:center}
.st-card .n{font-size:26px;font-weight:800}
.st-card .l{font-size:12.5px;color:var(--sub);margin-top:2px}
.st-card.g .n{color:#0f7a3d} .st-card.o .n{color:#c96a2b} .st-card.r .n{color:#c0392b}
.st-sec{margin-top:20px;border-top:1px dashed var(--line);padding-top:16px}
.st-sec-h{font-size:15px;font-weight:800;margin-bottom:12px}
.st-row{margin-bottom:12px}
.st-top{display:flex;justify-content:space-between;font-size:13px;margin-bottom:5px}
.bar i.b{background:var(--blue)} .bar i.o{background:var(--orange)} .bar i.g{background:var(--green)}
.st-empty{color:var(--sub);font-size:13.5px;padding:10px 0}
.st-table{border:1px solid var(--line);border-radius:12px;overflow:hidden}
.st-tr{display:grid;grid-template-columns:1.4fr .7fr .8fr 1fr .6fr .6fr 1fr;gap:8px;padding:11px 14px;align-items:center;font-size:13.5px}
.st-th{background:var(--bg);font-weight:700;color:var(--sub);font-size:12.5px}
.st-tr-body{border-top:1px solid var(--line);cursor:pointer;transition:.15s}
.st-tr-body:hover{background:var(--bg)}
.st-tr-body.open{background:rgba(47,125,225,.06)}
.st-name{font-weight:700}
.st-tr span.g{color:#0f7a3d;font-weight:700}
.st-tr span.o{color:#c96a2b;font-weight:700}
.st-tr span.r{color:#c0392b;font-weight:700}
.st-detail{padding:6px 18px 16px 32px;background:var(--bg);border-top:1px solid var(--line)}
.st-weak{margin-top:10px;display:flex;gap:8px;flex-wrap:wrap;align-items:center;font-size:12.5px;color:var(--sub)}
.st-chip{background:#fff;border:1px solid var(--line);border-radius:20px;padding:3px 10px}
.st-chip em{font-style:normal;font-weight:700;color:#c0392b}
.st-weak-list{display:flex;flex-direction:column;gap:8px}
.st-weak-item{display:grid;grid-template-columns:34px 1fr 110px 64px 64px;gap:10px;align-items:center;
  background:var(--bg);border:1px solid var(--line);border-radius:10px;padding:10px 13px;font-size:13.5px}
.st-weak-item .rk{font-weight:800;color:var(--sub);text-align:center}
.st-weak-item .ti{font-weight:600}
.st-weak-item .ca{font-size:12px;color:var(--sub)}
.st-weak-item .rt{font-weight:700;text-align:right}
.st-weak-item .rt.g{color:#0f7a3d} .st-weak-item .rt.o{color:#c96a2b} .st-weak-item .rt.r{color:#c0392b}
.st-weak-item .nm{font-size:12.5px;color:var(--sub);text-align:right}

/* ==========================================================================
 * 教师：知识点排序
 * ========================================================================== */
.sort-modal{max-width:760px}

/* ---------- 知识点管理（教师） ---------- */
.manage-modal{max-width:820px}
.mk-form{display:grid;grid-template-columns:1fr 1fr;gap:12px 16px;margin-top:8px}
.mk-field{display:flex;flex-direction:column;gap:5px}
.mk-field.full{grid-column:1/-1}
.mk-field label{font-size:12px;color:var(--sub);font-weight:600}
.mk-field .auth-input,.mk-field select{width:100%;font:inherit;padding:9px 12px;border:1px solid var(--line);border-radius:10px;background:#fff;color:var(--ink)}
.mk-field .auth-input:focus,.mk-field select:focus{border-color:var(--blue);box-shadow:0 0 0 3px rgba(47,125,225,.12)}
.mk-field textarea.auth-input{resize:vertical;line-height:1.5}
.mk-list{max-height:54vh;overflow:auto;border:1px solid var(--line);border-radius:12px;background:#fff;margin-top:8px}
.mk-item{display:flex;align-items:center;gap:10px;padding:10px 14px;border-bottom:1px solid var(--line)}
.mk-item:last-child{border-bottom:none}
.mk-item:hover{background:var(--bg)}
.mk-info{flex:1;min-width:0}
.mk-title{font-size:14px;font-weight:600;display:flex;align-items:center;gap:8px}
.mk-id{font-size:10px;background:var(--bg);color:var(--sub);padding:1px 7px;border-radius:20px;font-weight:500}
.mk-tags{display:flex;gap:4px;flex-wrap:wrap;margin-top:4px}
.mk-tags em{font-style:normal;font-size:11px;background:var(--bg);color:var(--sub);padding:1px 8px;border-radius:20px}
.mk-ops{display:flex;gap:6px}
.mk-ops .so-up,.mk-ops .so-down{border:1px solid var(--line);background:#fff;border-radius:7px;padding:5px 10px;cursor:pointer;color:var(--sub);font-size:12px;white-space:nowrap}
.mk-ops .so-up:hover{border-color:var(--blue);color:var(--blue)}
.mk-ops .so-down:hover{border-color:#e2553b;color:#e2553b}
.mk-share textarea{width:100%;font-family:ui-monospace,Menlo,Consolas,monospace;font-size:12px;line-height:1.5}
.mk-label{display:block;font-size:12px;color:var(--sub);font-weight:600;margin:12px 0 5px}
.mk-warn{margin-top:12px;padding:11px 13px;border-radius:11px;font-size:13px;line-height:1.6;
  background:#fff4e8;border:1px solid #ffd9a8;color:#9a5b12}
.mk-warn.ok{background:#eaf7ee;border:1px solid #bfe6cb;color:#1f7a3d}
.mk-warn b{color:inherit}
@media (max-width:680px){ .mk-form{grid-template-columns:1fr} }

/* ===== 教师后台视图 ===== */
.admin-view{ max-width:1100px; margin:24px auto; padding:0 18px; }
.admin-wrap{ background:var(--card); border:1px solid var(--line); border-radius:16px; padding:22px; box-shadow:var(--shadow); }
body.admin .app-shell{ display:none !important; }
.admin-head{ display:flex; justify-content:space-between; align-items:flex-start; gap:16px; flex-wrap:wrap; }
.admin-head h2{ margin:0 0 6px; font-size:22px }
.admin-sub{ margin:0; color:var(--sub); font-size:14px }
.admin-status{ margin:14px 0; padding:10px 14px; background:#f3f7ff; border:1px solid #d7e6ff; border-radius:10px; font-size:14px; color:#27406b }
.admin-status .warn{ color:#c0392b; font-weight:600 }
.admin-status .ok{ color:#1f7a3d; font-weight:600 }
.admin-grid{ display:grid; grid-template-columns:repeat(4,1fr); gap:14px }
.admin-card{ display:flex; flex-direction:column; align-items:flex-start; gap:6px; text-align:left; padding:16px;
  background:#fff; border:1px solid var(--line); border-radius:12px; cursor:pointer; transition:.15s; font:inherit; color:inherit }
.admin-card:hover{ border-color:var(--blue); box-shadow:0 4px 14px rgba(47,125,225,.14); transform:translateY(-2px) }
.ac-ico{ font-size:24px }
.ac-t{ font-weight:700; font-size:16px }
.ac-d{ font-size:13px; color:var(--sub) }
.admin-tip{ margin:16px 0 0; font-size:13px; color:var(--sub); line-height:1.6 }
.admin-tip code{ background:#eef2f7; padding:1px 6px; border-radius:5px }
@media (max-width:820px){ .admin-grid{ grid-template-columns:repeat(2,1fr) } }


.so-tabs{display:flex;gap:8px;margin:14px 0;flex-wrap:wrap}
.so-tab{border:1px solid var(--line);background:#fff;color:var(--sub);padding:8px 14px;border-radius:10px;
  cursor:pointer;font-size:13.5px;font-weight:600;display:flex;align-items:center;gap:6px}
.so-tab em{font-style:normal;font-size:11px;background:var(--bg);padding:1px 7px;border-radius:8px}
.so-tab.active{background:var(--blue);color:#fff;border-color:transparent}
.so-tab.active em{background:rgba(255,255,255,.25);color:#fff}
.so-list{max-height:52vh;overflow:auto;border:1px solid var(--line);border-radius:12px;background:#fff}
.so-item{display:flex;align-items:center;gap:10px;padding:10px 14px;border-bottom:1px solid var(--line);cursor:grab}
.so-item:last-child{border-bottom:none}
.so-item:hover{background:var(--bg)}
.so-item.dragging{opacity:.45}
.so-item.over{border-top:2px solid var(--blue)}
.so-grip{color:#b7c3d1;font-size:13px;letter-spacing:-2px}
.so-no{width:24px;height:24px;border-radius:50%;background:var(--bg);color:var(--sub);
  display:grid;place-items:center;font-size:12px;font-weight:700;flex-shrink:0}
.so-title{flex:1;font-size:14px;font-weight:600}
.so-tags{display:flex;gap:4px;flex-wrap:wrap}
.so-tags em{font-style:normal;font-size:11px;background:var(--bg);color:var(--sub);padding:1px 8px;border-radius:20px}
.so-ops{display:flex;gap:5px}
.so-up,.so-down{border:1px solid var(--line);background:#fff;border-radius:7px;width:28px;height:26px;cursor:pointer;color:var(--sub);font-size:13px}
.so-up:hover,.so-down:hover{border-color:var(--blue);color:var(--blue)}
.so-msg{min-height:20px;font-size:13px;margin-top:10px}
.so-msg.ok{color:#0f7a3d;font-weight:600}

@media (max-width:820px){
  .st-tr{grid-template-columns:1.2fr .7fr .8fr .8fr;gap:6px;font-size:12.5px}
  .st-tr span:nth-child(n+5){display:none}
  .st-weak-item{grid-template-columns:28px 1fr 56px 56px}
  .st-weak-item .ca{display:none}
  .so-tags{display:none}
}

/* ==========================================================================
 * 侧边栏下拉分组（学习 / 教师 / 教师后台）
 * ========================================================================== */
.side-group .side-group-t{
  width:100%;display:flex;align-items:center;justify-content:space-between;
  background:none;border:none;cursor:pointer;font-family:inherit;
  font-size:11px;text-transform:uppercase;letter-spacing:.7px;color:#9aa9bb;
  padding:8px 8px 4px;font-weight:800;transition:.15s;
}
.side-group .side-group-t:hover{color:var(--blue)}
.side-group .side-group-t .caret{font-size:10px;transition:transform .2s;transform:rotate(180deg)}
.dd-group:not(.open) .side-group-t .caret{transform:rotate(-90deg)}
.side-group-body{display:flex;flex-direction:column;gap:3px}
.dd-group:not(.open) .side-group-body{display:none}
.home-link{border:1px solid var(--line);background:#fff;border-radius:11px;font-weight:700}
.home-link:hover{border-color:var(--blue)}
body.view-home .home-link{border-color:var(--blue);color:var(--blue);background:rgba(47,125,225,.06)}

/* ==========================================================================
 * 首页视图：只显示 Hero（大标题 + 统计卡 + 两个入口按钮），居中铺满
 * ========================================================================== */
body.view-home .guide,
body.view-home #grid,
body.view-home .foot{display:none !important}
body.view-home .hero{
  min-height:calc(100vh - 40px);
  display:flex;align-items:center;
}
body.view-home .hero-inner{padding:60px 40px;max-width:1180px;margin:0 auto}
body.view-home .hero h1{font-size:52px;line-height:1.2}
body.view-home .hero .hl2{font-size:.85em}
body.view-home .hero p{font-size:16.5px}
body.view-home .hero-stats{margin-top:36px}
@media (max-width:960px){
  body.view-home .hero h1{font-size:40px}
}
@media (max-width:600px){
  body.view-home .hero h1{font-size:32px}
}

/* 卡片上的「已绑定互动」徽标 */
.card .emb{
  position:absolute;top:14px;right:14px;font-size:11px;font-weight:700;
  color:var(--blue);background:rgba(47,125,225,.1);border:1px solid rgba(47,125,225,.28);
  padding:2px 9px;border-radius:20px;
}

/* ==========================================================================
 * 教师后台 · 用户管理（useradmin.js）
 * ========================================================================== */
.ua-head{display:flex;justify-content:space-between;align-items:flex-start;gap:14px;flex-wrap:wrap}
.ua-search{max-width:230px}
.ua-tip{min-height:20px;font-size:13px;margin-bottom:8px}
.ua-tip .ok{color:var(--green)}
.ua-tip .warn{color:#d64545}
.ua-table{border:1px solid var(--line);border-radius:14px;overflow:hidden}
.ua-row{
  display:grid;grid-template-columns:1.3fr .8fr 1fr 1.3fr;gap:10px;align-items:center;
  padding:11px 16px;border-bottom:1px solid var(--line);background:#fff;font-size:13.5px;
}
.ua-row:last-child{border-bottom:none}
.ua-row-h{background:var(--bg);font-size:12px;color:var(--sub);font-weight:700}
.ua-row:not(.ua-row-h):hover{background:#f7fafd}
.ua-id{font-weight:700;font-variant-numeric:tabular-nums;color:var(--ink)}
.ua-me{font-size:12px;color:var(--blue);font-weight:600}
.ua-role{font-size:12px}
.ua-role.s{color:var(--blue)}
.ua-role.t{color:var(--orange)}
.ua-date{color:var(--sub);font-variant-numeric:tabular-nums}
.ua-ops{display:flex;gap:8px;justify-content:flex-end;flex-wrap:wrap}
.ua-btn{
  font-size:12px;padding:5px 11px;border-radius:9px;border:1px solid var(--line);
  background:#fff;cursor:pointer;color:var(--ink);transition:.15s;
}
.ua-btn:hover{border-color:var(--blue);color:var(--blue)}
.ua-btn.danger:hover{border-color:#d64545;color:#d64545}
.ua-btn:disabled{opacity:.45;cursor:not-allowed}
.ua-empty{padding:26px;text-align:center;color:var(--sub);font-size:13.5px}
@media (max-width:700px){
  .ua-row{grid-template-columns:1fr auto;grid-auto-rows:auto}
  .ua-row-h{display:none}
  .ua-date{grid-column:1}
  .ua-ops{grid-column:1/-1;justify-content:flex-start}
}

/* ---------- 发布到网站：步骤指引 + 线上同步检查 ---------- */
.mk-steps{display:flex;flex-direction:column;gap:8px;margin:12px 0}
.mk-step{
  background:var(--bg);border:1px solid var(--line);border-radius:12px;
  padding:10px 14px;font-size:13.5px;line-height:1.65;color:var(--ink);
}
.mk-step b{color:var(--blue)}
.mk-step code{
  background:rgba(47,125,225,.08);border-radius:6px;padding:1px 6px;
  font-size:12.5px;color:var(--blue);
}
.mk-step a{color:var(--blue)}
.mk-check{
  background:#fff;border:1px solid var(--line);border-radius:14px;
  padding:14px 16px;margin-top:4px;
}
.mk-check .mk-label{font-size:12.5px;color:var(--sub);display:block;margin-bottom:6px}