/* ============================================================
   图谱浏览页  explore/
   三栏：左筛选/列表 · 中 SVG 局部先修图 · 右知识点详情
   ============================================================ */
html,body{height:100%}
body{overflow:hidden}

.explore{
  display:grid;
  grid-template-columns:296px minmax(0,1fr) 372px;
  height:calc(100vh - var(--nav-h));
}

/* ---------------- 左栏 ---------------- */
.side{
  border-right:1px solid var(--line);
  background:#fbfcfd;
  display:flex;flex-direction:column;
  min-height:0;
}
.side-hd{padding:16px 16px 12px;border-bottom:1px solid var(--line2)}
.search{
  position:relative;
}
.search input{
  width:100%;font-family:inherit;font-size:14px;color:var(--ink);
  padding:9px 12px 9px 34px;border:1px solid var(--line);border-radius:9px;
  background:#fff;outline:none;transition:.15s;
}
.search input:focus{border-color:#b9c6e6;box-shadow:0 0 0 3px rgba(37,99,235,.1)}
.search .si{position:absolute;left:11px;top:50%;transform:translateY(-50%);color:var(--ink4);font-size:14px}
.filters{display:flex;gap:6px;margin-top:10px;flex-wrap:wrap}
.filters select{
  flex:1 1 auto;font-family:inherit;font-size:12.5px;color:var(--ink2);
  padding:6px 8px;border:1px solid var(--line);border-radius:8px;background:#fff;cursor:pointer;
  outline:none;min-width:0;
}
.filters select:focus{border-color:#b9c6e6}

.list{overflow-y:auto;padding:8px 8px 24px;flex:1;min-height:0}
.list::-webkit-scrollbar,.detail::-webkit-scrollbar{width:9px}
.list::-webkit-scrollbar-thumb,.detail::-webkit-scrollbar-thumb{background:#dfe3ea;border-radius:8px}
.grp-hd{
  display:flex;align-items:center;gap:8px;
  font-size:12px;font-weight:750;color:var(--ink3);letter-spacing:.02em;
  padding:12px 10px 6px;cursor:pointer;user-select:none;
}
.grp-hd .dot{width:7px;height:7px;border-radius:50%}
.grp-hd .cnt{margin-left:auto;font-weight:600;color:var(--ink4)}
.grp-hd .chev{font-size:10px;color:var(--ink4);transition:.15s}
.grp.collapsed .chev{transform:rotate(-90deg)}
.grp.collapsed .grp-body{display:none}
.unit-hd{font-size:11.5px;color:var(--ink4);padding:7px 10px 3px 22px;font-weight:600}
.titem{
  display:block;padding:7px 10px 7px 22px;border-radius:8px;cursor:pointer;
  font-size:13px;color:var(--ink2);line-height:1.45;border:1px solid transparent;
}
.titem:hover{background:#eef2f8;color:var(--ink);text-decoration:none}
.titem.sel{background:var(--brand-tint);color:var(--brand-ink);border-color:#cddafc;font-weight:650}
.titem .nm{display:block}
.titem .sub{font-size:11px;color:var(--ink4);font-weight:500}
.titem.sel .sub{color:#5b7bd4}

/* ---------------- 中栏 图谱 ---------------- */
.graph-wrap{position:relative;background:
  radial-gradient(circle at 1px 1px, #e7ebf1 1px, transparent 0) 0 0/22px 22px, #fbfcfd;
  overflow:hidden;min-width:0}
#graph{display:block;width:100%;height:100%;cursor:grab}
#graph.dragging{cursor:grabbing}

.g-legend{
  position:absolute;left:16px;bottom:16px;z-index:5;display:flex;flex-direction:column;gap:7px;
  background:rgba(255,255,255,.92);border:1px solid var(--line);border-radius:11px;
  padding:11px 13px;font-size:11.5px;color:var(--ink2);box-shadow:var(--shadow-sm);backdrop-filter:blur(4px);
}
.g-legend .row{display:flex;align-items:center;gap:8px}
.g-legend .sw{width:15px;height:10px;border-radius:3px;flex:none}
.g-legend .ln{width:20px;height:0;border-top:2px solid;flex:none}
.g-legend .ln.dash{border-top-style:dashed}

.g-tools{
  position:absolute;right:16px;top:16px;z-index:5;display:flex;flex-direction:column;gap:6px;
}
.g-tools button{
  width:34px;height:34px;border:1px solid var(--line);background:#fff;border-radius:9px;
  cursor:pointer;color:var(--ink2);font-size:15px;display:grid;place-items:center;
  box-shadow:var(--shadow-sm);transition:.12s;font-family:inherit;
}
.g-tools button:hover{background:#f4f6fa;color:var(--ink)}

.g-depth{
  position:absolute;left:50%;transform:translateX(-50%);top:16px;z-index:5;
  display:flex;align-items:center;gap:10px;background:rgba(255,255,255,.92);
  border:1px solid var(--line);border-radius:11px;padding:7px 12px;font-size:12px;color:var(--ink3);
  box-shadow:var(--shadow-sm);backdrop-filter:blur(4px);white-space:nowrap;
}
.g-depth .seg{display:flex;background:#f1f3f7;border-radius:8px;padding:2px}
.g-depth .seg button{
  border:none;background:transparent;font-family:inherit;font-size:12px;color:var(--ink3);
  padding:4px 9px;border-radius:6px;cursor:pointer;font-weight:600;
}
.g-depth .seg button.on{background:#fff;color:var(--brand-ink);box-shadow:var(--shadow-sm)}
.g-hint{
  position:absolute;left:50%;bottom:16px;transform:translateX(-50%);
  font-size:12px;color:var(--ink4);background:rgba(255,255,255,.9);padding:5px 12px;border-radius:8px;
  pointer-events:none;
}

/* SVG 元素 */
.edge{fill:none;transition:opacity .15s}
.edge.hard{stroke:var(--hard);stroke-width:1.7;stroke-opacity:.5}
.edge.soft{stroke:var(--soft);stroke-width:1.6;stroke-dasharray:5 4;stroke-opacity:.6}
.edge.dim{opacity:.12}
.edge.hi{stroke-opacity:.95;stroke-width:2.6}

.node{cursor:pointer}
.node rect{stroke-width:1.5;transition:.15s}
.node:hover rect{stroke-width:2.4}
.node-label{font-size:12.5px;font-weight:600;pointer-events:none;text-anchor:middle;dominant-baseline:middle}
.node-sub{font-size:9.5px;font-weight:500;pointer-events:none;text-anchor:middle;dominant-baseline:middle}

/* 年级配色（描边+淡填充） */
.node.g4 rect{fill:var(--g4t);stroke:var(--g4)}
.node.g5 rect{fill:var(--g5t);stroke:var(--g5)}
.node.g6 rect{fill:var(--g6t);stroke:var(--g6)}
.node.g3 rect{fill:#fff;stroke:var(--g3);stroke-dasharray:4 3}
.node.g4 .node-label{fill:var(--g4)}
.node.g5 .node-label{fill:var(--g5)}
.node.g6 .node-label{fill:var(--g6)}
.node.g3 .node-label{fill:var(--g3)}
.node.sel rect{stroke-width:2.6;filter:drop-shadow(0 4px 10px rgba(20,30,50,.18))}
.node.sel.g4 rect{fill:var(--g4)} .node.sel.g5 rect{fill:var(--g5)} .node.sel.g6 rect{fill:var(--g6)}
.node.sel .node-label{fill:#fff}
.node.sel .node-sub{fill:rgba(255,255,255,.85)}
.node.faded{opacity:.35}

/* ---------------- 右栏 详情 ---------------- */
.detail{
  border-left:1px solid var(--line);background:#fff;overflow-y:auto;min-height:0;padding:22px 22px 40px;
}
.d-empty{color:var(--ink4);font-size:13.5px;text-align:center;padding:60px 20px;line-height:1.8}
.d-gradeline{display:flex;gap:6px;flex-wrap:wrap;margin-bottom:12px}
.d-title{font-size:22px;font-weight:800;letter-spacing:-.02em;line-height:1.3;margin:0 0 6px}
.d-unit{font-size:12.5px;color:var(--ink3);margin-bottom:16px;line-height:1.5}
.d-sec{margin-top:20px}
.d-sec h4{font-size:11.5px;font-weight:750;letter-spacing:.06em;color:var(--ink4);
  text-transform:uppercase;margin:0 0 9px;display:flex;align-items:center;gap:7px}
.d-sec h4 .bar{width:3px;height:12px;border-radius:2px;background:var(--ink4)}
.d-desc{font-size:14px;color:var(--ink2);line-height:1.72}
.d-mastery{margin:0;padding:0;list-style:none}
.d-mastery li{position:relative;padding-left:20px;font-size:13.5px;color:var(--ink2);margin:7px 0;line-height:1.55}
.d-mastery li::before{content:"✓";position:absolute;left:0;top:0;color:var(--up);font-weight:700;font-size:12px}
.d-exam{background:#fbfcfd;border:1px solid var(--line2);border-radius:10px;padding:12px 14px;font-size:13px;color:var(--ink2);line-height:1.6}
.d-exam .lv{font-weight:700}
.d-exam .w{font-variant-numeric:tabular-nums;font-weight:700;color:var(--ink)}
.d-rel{display:flex;flex-direction:column;gap:6px}
.rel-item{
  display:flex;align-items:flex-start;gap:8px;font-size:13px;padding:8px 10px;border-radius:9px;
  border:1px solid var(--line2);background:#fcfdfe;cursor:pointer;transition:.12s;
}
.rel-item:hover{border-color:#cfd9ef;background:#f5f8ff}
.rel-item .rt{flex:1;min-width:0}
.rel-item .rn{font-weight:600;color:var(--ink);line-height:1.4}
.rel-item .rw{font-size:11.5px;color:var(--ink4);line-height:1.45;margin-top:1px}
.rel-empty{font-size:12.5px;color:var(--ink4);padding:4px 2px}
.d-actions{display:flex;gap:8px;margin-top:22px;flex-wrap:wrap}
.d-qcount{display:inline-flex;align-items:center;gap:6px;font-size:12.5px;color:var(--ink2);
  background:#f1f3f7;border-radius:8px;padding:5px 11px;margin-top:4px}

/* 滚动条 */
.detail::-webkit-scrollbar-thumb{background:#e3e7ee}

@media(max-width:1180px){
  .explore{grid-template-columns:264px minmax(0,1fr) 330px}
}
@media(max-width:980px){
  body{overflow:auto}
  .explore{grid-template-columns:1fr;height:auto}
  .side{max-height:320px;border-right:none;border-bottom:1px solid var(--line)}
  .graph-wrap{height:60vh}
  .detail{border-left:none;border-top:1px solid var(--line)}
}

/* ============================================================
   手机 / 微信内：左侧列表变抽屉，图谱在上、详情在下
   ============================================================ */
.side-toggle{
  display:none;position:absolute;left:12px;bottom:12px;z-index:6;
  align-items:center;gap:6px;font-family:inherit;font-size:12.5px;font-weight:650;
  color:#fff;background:var(--ink);border:none;border-radius:99px;
  padding:8px 14px;box-shadow:0 8px 20px -10px rgba(20,30,50,.75);cursor:pointer;
}
.side-close{
  display:none;position:absolute;right:10px;top:10px;z-index:3;
  width:30px;height:30px;border:1px solid var(--line);border-radius:8px;background:#fff;
  color:var(--ink3);font-family:inherit;font-size:13px;cursor:pointer;align-items:center;justify-content:center;
}

@media(max-width:760px){
  html,body{height:auto}
  body{overflow:auto}
  .side{
    position:fixed;left:0;right:0;top:var(--nav-h);bottom:0;z-index:80;
    max-height:none;background:#fff;border:none;
    transform:translateX(-102%);transition:transform .26s cubic-bezier(.4,0,.2,1);
    box-shadow:14px 0 44px -20px rgba(20,30,50,.4);
  }
  .side.open{transform:none}
  .side-hd{position:relative;padding:12px 14px 10px}
  .side-hd .search input{padding-right:46px}
  .side-close{display:flex}
  .graph-wrap{height:52vh;height:52svh;min-height:270px;border-bottom:1px solid var(--line)}
  .detail{padding:18px 16px 46px}
  .d-title{font-size:19px}
  .d-unit{font-size:12px;margin-bottom:12px}
  .d-desc{font-size:13.5px}
  .d-mastery li{font-size:13px}
  .d-empty{padding:36px 12px;font-size:13px}
  .g-legend{display:none}
  .g-hint{display:none}
  .g-depth{left:10px;transform:none;top:10px;padding:5px 8px;font-size:11px;gap:7px}
  .g-depth .seg button{padding:3px 7px;font-size:11px}
  .g-tools{right:10px;top:10px;gap:5px}
  .g-tools button{width:30px;height:30px;font-size:14px;border-radius:8px}
  .node-label{font-size:11px}
  .node-sub{font-size:9px}
  .side-toggle{display:flex}
  .d-actions .btn{flex:1 1 auto}
}