:root{
  --blue:#1d4ed8; --blue-dark:#1e3a8a; --blue-soft:#eef2ff;
  --orange:#ea580c; --orange-soft:#fff7ed;
  --green:#047857; --green-soft:#ecfdf5;
  --ink:#1f2937; --ink2:#4b5563; --ink3:#8b94a3;
  --line:#e5e8f0; --bg:#f5f7fb; --card:#fff;
  --radius:12px;
  --shadow:0 1px 2px rgba(16,24,40,.04), 0 8px 24px rgba(16,24,40,.06);
}
*{box-sizing:border-box;}
html,body{margin:0;padding:0;}
body{
  font-family:system-ui,-apple-system,"PingFang SC","Microsoft YaHei",sans-serif;
  background:var(--bg); color:var(--ink); line-height:1.6;
  font-size:14px;
}
h1,h2,h3,h4,p,ul{margin:0;}
ul{list-style:none;padding:0;}
button{font-family:inherit;cursor:pointer;}
.hidden{display:none !important;}

/* ---------------- 顶栏 ---------------- */
.topbar{
  position:sticky; top:0; z-index:20;
  display:flex; align-items:center; justify-content:space-between; gap:16px;
  padding:12px 24px; background:linear-gradient(100deg,#1e3a8a,#1d4ed8 55%,#2563eb);
  color:#fff; box-shadow:0 2px 14px rgba(30,58,138,.25); flex-wrap:wrap;
}
.brand{display:flex; align-items:center; gap:12px;}
.logo{
  width:38px;height:38px;border-radius:10px;background:rgba(255,255,255,.16);
  display:grid;place-items:center;font-size:19px;font-weight:700;
  border:1px solid rgba(255,255,255,.25);
}
.brand-txt h1{font-size:17px;font-weight:600;letter-spacing:.5px;}
.brand-txt p{font-size:12px;opacity:.8;}
.mode-switch{display:flex;background:rgba(255,255,255,.14);border-radius:10px;padding:3px;}
.mode-switch button{
  border:0;background:transparent;color:#fff;padding:7px 18px;border-radius:8px;
  font-size:13.5px;font-weight:500;transition:.18s;
}
.mode-switch button.on{background:#fff;color:var(--blue-dark);font-weight:600;}

/* ---------------- 面板 ---------------- */
main{padding:18px 24px 40px;max-width:1440px;margin:0 auto;}

.picker{
  background:var(--card);border-radius:var(--radius);box-shadow:var(--shadow);
  padding:6px 18px 10px;margin-bottom:14px;
}
.pick-row{display:flex;align-items:flex-start;gap:14px;padding:8px 0;border-bottom:1px solid var(--line);}
.pick-row:last-child{border-bottom:0;}
.pick-row label{
  flex:0 0 62px;font-size:13px;color:var(--ink3);padding-top:6px;font-weight:500;
}
.chips{display:flex;flex-wrap:wrap;gap:7px;}
.chips button{
  border:1px solid var(--line);background:#fff;color:var(--ink2);
  padding:5px 13px;border-radius:16px;font-size:13px;transition:.15s;
}
.chips button:hover{border-color:#b9c6f5;color:var(--blue);}
.chips button.on{
  background:var(--blue);border-color:var(--blue);color:#fff;font-weight:500;
  box-shadow:0 2px 8px rgba(29,78,216,.28);
}
.chips button.on.ghost{background:var(--blue-dark);}

/* ---------------- 两栏 ---------------- */
.split{display:grid;grid-template-columns:330px minmax(0,1fr);gap:14px;align-items:start;}
.col-lessons,.col-detail{
  background:var(--card);border-radius:var(--radius);box-shadow:var(--shadow);
}
.col-lessons{max-height:calc(100vh - 250px);display:flex;flex-direction:column;overflow:hidden;}
.col-head{
  display:flex;align-items:center;justify-content:space-between;
  padding:12px 14px;border-bottom:1px solid var(--line);font-size:13px;font-weight:600;
}
.mini{font-size:12px;color:var(--ink3);font-weight:400;display:flex;align-items:center;gap:5px;cursor:pointer;}
.lesson-list{overflow-y:auto;padding:6px 0;flex:1;}
.lesson-list .unit-group{
  padding:10px 14px 4px;font-size:12px;color:var(--blue-dark);font-weight:600;
  letter-spacing:.3px;background:linear-gradient(90deg,var(--blue-soft),transparent);
}
.lesson-list li.item{
  padding:8px 14px 8px 16px;font-size:13.5px;cursor:pointer;border-left:3px solid transparent;
  display:flex;align-items:flex-start;gap:7px;transition:.12s;
}
.lesson-list li.item:hover{background:#f7f9ff;}
.lesson-list li.item.on{background:var(--blue-soft);border-left-color:var(--blue);font-weight:600;color:var(--blue-dark);}
.lesson-list li.item.box-item{color:var(--ink3);font-size:12.5px;}
.badge{
  flex:0 0 auto;font-size:10px;padding:1px 6px;border-radius:8px;font-weight:600;
  line-height:1.5;margin-top:2px;
}
.badge.kx{background:var(--orange-soft);color:var(--orange);border:1px solid #fed7aa;}
.badge.n{background:#eef2ff;color:#4338ca;}

/* ---------------- 详情 ---------------- */
.col-detail{min-height:420px;padding:0 0 18px;}
.empty-hint{padding:80px 30px;text-align:center;color:var(--ink3);}
.empty-hint .big{font-size:16px;color:var(--ink2);margin-bottom:8px;}

.detail-head{padding:16px 20px 14px;border-bottom:1px solid var(--line);}
.detail-head .crumb{font-size:12px;color:var(--ink3);margin-bottom:5px;}
.detail-head h2{font-size:19px;line-height:1.4;}
.detail-head .origin{
  margin-top:9px;font-size:12.5px;color:var(--ink2);background:#f8f9fc;
  border-left:3px solid #cbd5e1;padding:7px 11px;border-radius:0 8px 8px 0;
  max-height:96px;overflow-y:auto;
}
.tagline{display:flex;flex-wrap:wrap;gap:6px;margin-top:10px;}
.tag{
  font-size:11.5px;padding:2px 9px;border-radius:12px;background:var(--blue-soft);
  color:var(--blue-dark);border:1px solid #dbe3ff;
}
.tag.hit{background:var(--orange-soft);color:var(--orange);border-color:#fed7aa;font-weight:600;}

.link-section{padding:14px 20px 0;}
.link-section h3{
  font-size:13px;color:var(--ink3);font-weight:600;margin-bottom:10px;
  display:flex;align-items:center;gap:8px;
}
.link-section h3::after{content:"";flex:1;height:1px;background:var(--line);}
.link-card{
  border:1px solid var(--line);border-radius:10px;padding:11px 14px;margin-bottom:9px;
  transition:.15s;background:#fff;
}
.link-card:hover{border-color:#c7d2fe;box-shadow:0 4px 14px rgba(29,78,216,.07);}
.link-card .lc-top{display:flex;align-items:baseline;gap:8px;flex-wrap:wrap;}
.subj-dot{
  font-size:11px;font-weight:600;padding:1px 8px;border-radius:6px;white-space:nowrap;
}
.link-card .lc-title{font-weight:600;font-size:14px;}
.link-card .lc-loc{font-size:11.5px;color:var(--ink3);}
.link-card .lc-why{font-size:12.5px;color:var(--ink2);margin-top:5px;}
.link-card .lc-why b{color:var(--orange);font-weight:600;}
.link-card .lc-text{
  font-size:12.5px;color:var(--ink3);margin-top:6px;line-height:1.55;
  display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden;
}

/* ---------------- 搜索 ---------------- */
.search-box{display:flex;gap:10px;margin-bottom:12px;}
.search-box input{
  flex:1;padding:13px 16px;border:1px solid var(--line);border-radius:var(--radius);
  font-size:15px;font-family:inherit;background:#fff;box-shadow:var(--shadow);outline:none;
}
.search-box input:focus{border-color:var(--blue);box-shadow:0 0 0 3px rgba(29,78,216,.12);}
.search-box button{
  padding:0 26px;border:0;border-radius:var(--radius);background:var(--blue);color:#fff;
  font-size:15px;font-weight:600;box-shadow:0 4px 14px rgba(29,78,216,.25);
}
.chips.hot{margin-bottom:16px;}
.chips.hot button{font-size:12.5px;background:#fff;}
.search-result{display:flex;flex-direction:column;gap:14px;}
.result-block{
  background:var(--card);border-radius:var(--radius);box-shadow:var(--shadow);padding:14px 18px 16px;
}
.result-block > h3{
  font-size:14px;display:flex;align-items:center;gap:8px;margin-bottom:10px;color:var(--ink);
}
.result-block h3 .cnt{font-size:11.5px;color:var(--ink3);font-weight:400;}
.result-empty{text-align:center;color:var(--ink3);padding:60px 20px;background:#fff;border-radius:var(--radius);}
mark{background:#fff3c4;color:#92400e;padding:0 2px;border-radius:3px;}

/* ---------------- 课标依据 ---------------- */
.std-card{
  background:var(--green-soft);border:1px solid #a7f3d0;border-radius:10px;
  padding:11px 14px;margin-bottom:10px;
}
.std-card .sc-top{display:flex;align-items:center;gap:8px;flex-wrap:wrap;}
.std-card .sc-tag{font-size:11px;font-weight:600;color:var(--green);background:#d1fae5;padding:1px 8px;border-radius:6px;}
.std-card .sc-title{font-weight:600;font-size:13.5px;}
.std-card .sc-sum{font-size:12.5px;color:#065f46;margin-top:5px;line-height:1.6;}
.std-card .sc-inv{font-size:11.5px;color:#047857;margin-top:5px;}

/* ---------------- 页脚 ---------------- */
.foot{
  text-align:center;color:var(--ink3);font-size:11.5px;padding:0 20px 26px;line-height:1.9;
}

/* ---------------- 响应式 ---------------- */
@media (max-width:900px){
  .split{grid-template-columns:1fr;}
  .col-lessons{max-height:320px;}
  main{padding:14px;}
  .topbar{padding:10px 14px;}
  .brand-txt p{display:none;}
}

/* ---------------- 主题案例 ---------------- */
.themes-intro{
  background:var(--card);border-radius:var(--radius);box-shadow:var(--shadow);
  padding:16px 20px;margin-bottom:14px;
}
.themes-intro h2{font-size:17px;margin-bottom:6px;}
.themes-intro p{font-size:13px;color:var(--ink2);line-height:1.7;}
.themes-intro b{color:var(--blue-dark);}
.themes-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(330px,1fr));gap:14px;align-items:start;}
.theme-card{
  background:var(--card);border-radius:var(--radius);box-shadow:var(--shadow);
  padding:15px 18px;cursor:pointer;transition:.15s;border:1px solid transparent;
}
.theme-card:hover{border-color:#c7d2fe;box-shadow:0 6px 20px rgba(29,78,216,.1);transform:translateY(-1px);}
.theme-card h3{font-size:15.5px;margin-bottom:5px;color:var(--blue-dark);}
.theme-card .tc-sub{font-size:11.5px;color:var(--ink3);margin-bottom:8px;}
.theme-card .tc-sum{font-size:12.5px;color:var(--ink2);line-height:1.68;}
.theme-card .tc-meta{font-size:11.5px;color:var(--blue);margin-top:10px;display:flex;gap:10px;flex-wrap:wrap;}
.theme-card .tc-meta span{background:var(--blue-soft);padding:1px 8px;border-radius:8px;}
.theme-open{
  grid-column:1/-1;background:var(--card);border-radius:var(--radius);box-shadow:var(--shadow);
  padding:18px 22px 20px;
}
.theme-open .to-top{display:flex;justify-content:space-between;align-items:flex-start;gap:14px;}
.theme-open h2{font-size:18px;margin-bottom:6px;color:var(--blue-dark);}
.theme-open .close-x{
  border:1px solid var(--line);background:#fff;border-radius:8px;padding:4px 12px;
  font-size:12.5px;color:var(--ink2);flex:0 0 auto;
}
.theme-open .to-sub{font-size:12px;color:var(--ink3);margin-bottom:10px;}
.theme-open .to-sum{font-size:13.5px;color:var(--ink2);line-height:1.75;background:#f8f9fc;padding:10px 14px;border-radius:8px;margin-bottom:14px;}
.anchor-row{display:flex;gap:12px;padding:9px 0;border-bottom:1px dashed var(--line);font-size:13px;}
.anchor-row:last-child{border-bottom:0;}
.anchor-row .an-where{flex:0 0 118px;color:var(--ink3);font-size:11.5px;line-height:1.5;padding-top:1px;}
.anchor-row .an-body{flex:1;min-width:0;}
.anchor-row .an-title{font-weight:600;}
.anchor-row .an-note{color:var(--ink2);font-size:12.5px;margin-top:3px;line-height:1.6;}
.anchor-row .an-go{color:var(--blue);font-size:11.5px;cursor:pointer;text-decoration:underline;}
.act-list{font-size:13px;line-height:1.95;padding-left:20px;list-style:disc;color:var(--ink2);}
.sec-title{font-size:13px;color:var(--ink3);font-weight:600;margin:16px 0 8px;display:flex;align-items:center;gap:8px;}
.sec-title::after{content:"";flex:1;height:1px;background:var(--line);}

.tag.clickable{cursor:pointer;transition:.15s;}
.tag.clickable:hover{background:#dbe3ff;border-color:#a5b4fc;}

.tag.broad{background:#f4f6f9;color:#7b8794;border-color:#e3e8ef;border-style:dashed;}
.tag.broad:hover{background:#e9edf3;}

.badge.star{background:#fef3c7;color:#b45309;border:1px solid #fcd34d;font-size:11px;}