/* 空调变频电控学习站 · 全站样式（无外部依赖） */
:root{
  --main:#1565c0; --main-l:#e3f2fd; --warn:#c62828; --ok:#2e7d32; --orange:#ef6c00;
  --bg:#f5f7fa; --card:#fff; --line:#dde3ea; --text:#222; --muted:#6b7280;
  --sup:#6a1b9a; --sup-bg:#f6effa;
  --radius:10px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--text);
  font-family:"PingFang SC","Microsoft YaHei","Noto Sans CJK SC","WenQuanYi Micro Hei",system-ui,sans-serif;
  line-height:1.75;font-size:15.5px;-webkit-text-size-adjust:100%}
a{color:var(--main)}
img,svg,canvas,iframe{max-width:100%}
code,kbd{background:#eef2f7;border-radius:4px;padding:0 5px;font-size:.92em}

/* 顶栏 */
.topbar{background:var(--main);color:#fff;position:sticky;top:0;z-index:50;box-shadow:0 1px 4px rgba(0,0,0,.15)}
.topbar .in{max-width:1240px;margin:0 auto;display:flex;align-items:center;gap:14px;padding:10px 20px;flex-wrap:wrap}
.topbar .brand{color:#fff;text-decoration:none;font-weight:700;font-size:17px;white-space:nowrap}
.topbar .brand small{font-weight:400;opacity:.8;margin-left:6px;font-size:12px}
.topbar nav{display:flex;gap:4px;flex-wrap:wrap;margin-left:auto}
.topbar nav a{color:#fff;text-decoration:none;padding:4px 10px;border-radius:6px;font-size:14px;opacity:.92}
.topbar nav a:hover,.topbar nav a.on{background:rgba(255,255,255,.18);opacity:1}
.menu-btn{display:none;margin-left:auto;background:rgba(255,255,255,.15);border:0;color:#fff;border-radius:6px;padding:4px 10px;font-size:15px;cursor:pointer}

/* 布局 */
.wrap{max-width:1240px;margin:0 auto;padding:22px 20px 60px}
.layout{display:grid;grid-template-columns:230px minmax(0,1fr);gap:28px;align-items:start}
.toc{position:sticky;top:64px;max-height:calc(100vh - 80px);overflow:auto;font-size:14px;
  background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:12px 14px}
.toc h4{margin:0 0 6px;font-size:13px;color:var(--muted);letter-spacing:.05em}
.toc ol{list-style:none;margin:0;padding:0}
.toc li a{display:block;padding:3px 6px;border-radius:5px;text-decoration:none;color:#374151;border-left:3px solid transparent}
.toc li a:hover{background:var(--main-l)}
.toc li a.active{border-left-color:var(--main);color:var(--main);font-weight:600;background:var(--main-l)}
.toc li.lv3 a{padding-left:18px;font-size:13px;color:var(--muted)}
.toc .toc-chapters{margin-top:12px;border-top:1px dashed var(--line);padding-top:8px}

main.content{min-width:0}
.hero{background:linear-gradient(135deg,#1565c0,#1e88e5 60%,#26a69a);color:#fff;border-radius:14px;padding:26px 28px;margin-bottom:22px}
.hero h1{margin:0 0 6px;font-size:26px;line-height:1.35}
.hero p{margin:4px 0;opacity:.95}
.hero .meta{font-size:13px;opacity:.85}
.page-title{margin:0 0 4px;font-size:25px}
.kicker{color:var(--muted);font-size:13px;margin:0 0 14px}
h2{font-size:20px;margin:34px 0 12px;padding-bottom:6px;border-bottom:2px solid var(--line);scroll-margin-top:70px}
h3{font-size:17px;margin:20px 0 8px;scroll-margin-top:70px}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:16px 18px;margin-bottom:16px}
.core{background:var(--main-l);border-left:5px solid var(--main);padding:10px 16px;border-radius:8px;margin:12px 0 18px}
.core b{color:var(--main)}

/* 来源标注 */
.src{display:inline-block;font-size:12px;padding:0 8px;border-radius:10px;vertical-align:middle;margin-left:6px;font-weight:500;line-height:20px}
.src.ys{background:#e8f5e9;color:var(--ok);border:1px solid #a5d6a7}
.src.demo{background:#e3f2fd;color:var(--main);border:1px solid #90caf9}
.src.sup{background:var(--sup-bg);color:var(--sup);border:1px solid #ce93d8}
.supplement{background:var(--sup-bg);border:1px dashed #ab47bc;border-left:5px solid #8e24aa;border-radius:8px;padding:10px 16px;margin:12px 0}
.supplement::before{content:"补充（通用知识）";display:inline-block;font-size:12px;font-weight:700;color:#fff;background:#8e24aa;border-radius:4px;padding:0 8px;margin-bottom:4px}
.supplement p:first-of-type{margin-top:4px}
.note{font-size:13px;color:var(--muted)}
.caution{background:#fff8e1;border-left:5px solid #f9a825;border-radius:8px;padding:8px 14px;margin:10px 0;font-size:14px}
.legend-key{display:flex;flex-wrap:wrap;gap:8px 16px;font-size:13px;margin:6px 0 14px;color:var(--muted)}

/* 知识点列表 */
ul.points{padding-left:0;list-style:none;margin:0}
ul.points li{position:relative;padding:6px 0 6px 28px;border-bottom:1px dotted #e3e7ec}
ul.points li:last-child{border-bottom:0}
ul.points li::before{content:"✔";position:absolute;left:4px;top:6px;color:var(--main);font-weight:700}

/* 名词表 */
dl.terms{margin:0}
dl.terms dt{font-weight:700;color:var(--main);margin-top:10px}
dl.terms dd{margin:2px 0 8px 0;padding-left:14px;border-left:3px solid var(--line)}
.term-note{width:100%;min-height:44px;border:1px dashed #b0bec5;border-radius:6px;padding:6px 8px;font:inherit;font-size:14px;background:#fcfcfd;resize:vertical}

/* 状态总结 */
.sum div{padding:7px 12px;margin:6px 0;border-radius:6px}
.sum .a{background:#e8f5e9;border-left:4px solid var(--ok)}
.sum .b{background:#fff3e0;border-left:4px solid var(--orange)}
.sum .c{background:#ffebee;border-left:4px solid var(--warn)}
.sum .d{background:var(--main-l);border-left:4px solid var(--main)}

/* 动图嵌入 */
.demo-embed{border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;background:#fff;margin:10px 0 18px}
.demo-embed .bar{display:flex;align-items:center;gap:10px;padding:8px 14px;background:#f0f4f9;border-bottom:1px solid var(--line);flex-wrap:wrap}
.demo-embed .bar b{font-size:15px}
.demo-embed .bar .sp{flex:1}
.demo-embed iframe{display:block;width:100%;border:0;background:#fafafa}
.btn{display:inline-block;font-size:13px;color:#fff;background:var(--main);padding:3px 12px;border-radius:5px;text-decoration:none;border:0;cursor:pointer;font-family:inherit;line-height:1.7}
.btn.ghost{background:#fff;color:var(--main);border:1px solid var(--main)}
.btn.ok{background:var(--ok)}
.predict{background:#fff8e1;border:1px dashed #f9a825;border-radius:8px;padding:8px 14px;margin:8px 0}
.predict .t{font-weight:700;color:#e65100}
.predict ol{margin:4px 0;padding-left:22px}

/* 图例 */
figure.fig{margin:10px 0 18px;background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:12px}
figure.fig img,figure.fig svg{display:block;margin:0 auto;height:auto}
figure.fig figcaption{font-size:13px;color:var(--muted);text-align:center;margin-top:6px}
.two{display:grid;grid-template-columns:1fr 1fr;gap:18px;align-items:start}

/* 问答 & 练习 */
.qa{border-left:4px solid var(--main);background:#fff;border-radius:8px;padding:10px 16px;margin:10px 0;border:1px solid var(--line);border-left-width:4px}
.qa .q{font-weight:700}
.qa .q::before{content:"问 ";color:var(--main)}
.qa .a::before{content:"正确理解 ";color:var(--ok);font-weight:700}
details.ans{margin:8px 0 14px;background:#f8fafc;border:1px solid var(--line);border-radius:8px;padding:6px 14px}
details.ans summary{cursor:pointer;color:var(--main);font-weight:600;outline:none}
details.ans[open]{background:#fff}
details.ans[open] summary{margin-bottom:6px}
ol.ex>li{margin-bottom:18px}
.tag{display:inline-block;font-size:12px;padding:0 8px;border-radius:10px;background:#fce4ec;color:var(--warn);margin-right:4px}
.tag.l{background:#ede7f6;color:#4527a0}
.tools{display:flex;gap:8px;flex-wrap:wrap;margin:6px 0 12px}

/* 小型交互 */
.widget{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:14px 16px;margin:12px 0 18px}
.widget .row{display:flex;flex-wrap:wrap;align-items:center;gap:8px 14px;margin:6px 0}
.widget input[type=range]{flex:1;min-width:160px;max-width:420px}
.widget .readout{background:var(--main-l);border-radius:6px;padding:6px 12px;font-size:15px}
.widget .readout b{color:var(--warn)}

/* 首页卡片 */
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(270px,1fr));gap:16px}
.ch-card{background:#fff;border:1px solid var(--line);border-radius:12px;padding:16px 18px;display:flex;flex-direction:column;gap:6px;text-decoration:none;color:inherit;transition:box-shadow .15s,transform .15s}
a.ch-card:hover{box-shadow:0 4px 16px rgba(21,101,192,.15);transform:translateY(-2px)}
.ch-card .day{font-size:12px;color:var(--muted)}
.ch-card h3{margin:0;font-size:17px;color:var(--main)}
.ch-card p{margin:0;font-size:14px}
.ch-card .st{margin-top:auto;font-size:12px;display:flex;gap:6px;flex-wrap:wrap}
.pill{display:inline-block;padding:0 8px;border-radius:10px;font-size:12px;line-height:20px}
.pill.done{background:#e8f5e9;color:var(--ok)}
.pill.todo{background:#eceff1;color:#546e7a}
.pill.rev{background:#e3f2fd;color:var(--main)}
.ch-card.locked{opacity:.75;border-style:dashed}
.stage{margin:8px 0 26px}
.stage>h2{margin-top:10px}
.progress{height:12px;background:#e3e7ec;border-radius:6px;overflow:hidden;margin:6px 0}
.progress>i{display:block;height:100%;background:linear-gradient(90deg,#43a047,#26a69a);border-radius:6px}
.demo-list{display:grid;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:14px}
.demo-item{background:#fff;border:1px solid var(--line);border-radius:10px;overflow:hidden;text-decoration:none;color:inherit;display:flex;flex-direction:column}
.demo-item img{width:100%;height:130px;object-fit:cover;object-position:top left;border-bottom:1px solid var(--line);background:#fafafa}
.demo-item .ph{height:130px;display:flex;align-items:center;justify-content:center;background:linear-gradient(135deg,#e3f2fd,#f3e5f5);font-size:30px;border-bottom:1px solid var(--line)}
.demo-item div.t{padding:8px 12px;font-size:14px}
.demo-item div.t b{display:block;color:var(--main)}
.demo-item:hover{box-shadow:0 4px 14px rgba(0,0,0,.08)}
.new{background:#ff7043;color:#fff;font-size:11px;border-radius:4px;padding:0 5px;margin-left:4px;vertical-align:middle}

/* 上下章 */
.pager{display:flex;justify-content:space-between;gap:12px;margin-top:36px;flex-wrap:wrap}
.pager a,.pager span{flex:1;min-width:200px;display:block;padding:12px 16px;border:1px solid var(--line);border-radius:10px;background:#fff;text-decoration:none}
.pager .next{text-align:right}
.pager small{display:block;color:var(--muted);font-size:12px}
.pager span{color:#9aa4b1;border-style:dashed}
footer.foot{text-align:center;color:var(--muted);font-size:12.5px;padding:24px 10px 40px}

table.t{border-collapse:collapse;width:100%;font-size:14px;background:#fff}
table.t th,table.t td{border:1px solid var(--line);padding:6px 10px;text-align:left;vertical-align:top}
table.t th{background:#f0f4f9}
.table-wrap{overflow-x:auto}

/* 响应式 */
@media (max-width:960px){
  .layout{grid-template-columns:1fr}
  .toc{position:static;max-height:none}
  .toc.collapsed ol{display:none}
}
@media (max-width:720px){
  body{font-size:15px}
  .wrap{padding:14px 12px 40px}
  .hero{padding:18px 16px}
  .hero h1{font-size:21px}
  .two{grid-template-columns:1fr}
  .menu-btn{display:inline-block}
  .topbar nav{display:none;width:100%;margin-left:0}
  .topbar nav.open{display:flex}
  .card{padding:12px 13px}
  h2{font-size:18px}
}
@media print{.topbar,.toc,.pager,.tools{display:none}.layout{display:block}details.ans{display:block}}

/* ===== v1.1 新增 ===== */
.src.dlg{background:#fff3e0;color:#e65100;border:1px solid #ffcc80}
.hint{background:#fffde7;border:1px solid #fff176;border-left:5px solid #fbc02d;border-radius:8px;padding:9px 16px;margin:10px 0 16px;font-size:14.5px}
.hint b{color:#f57f17}
/* 评审话术：严师原话 */
.say{position:relative;background:linear-gradient(135deg,#fff8e1,#fff3e0);border:2px solid #ffb300;border-radius:12px;padding:14px 18px 12px 52px;margin:12px 0;font-size:16px;line-height:1.8}
.say::before{content:"❝";position:absolute;left:14px;top:4px;font-size:40px;color:#ff8f00;line-height:1}
.say .who{display:block;font-size:12.5px;color:#8d6e63;margin-top:6px}
.say b{color:#bf360c}
.say.point{border-style:dashed;background:#fffaf0}
/* 问答内部分区 */
.qa .blk{margin:8px 0;padding:6px 12px;border-radius:6px;font-size:14.5px}
.qa .blk::before{display:block;font-weight:700;font-size:12.5px;margin-bottom:2px}
.qa .ok{background:#e8f5e9}.qa .ok::before{content:"✔ 正确理解";color:var(--ok)}
.qa .err{background:#ffebee}.qa .err::before{content:"✘ Alan 的错误 / 推理断点";color:var(--warn)}
.qa .chk{background:#e3f2fd}.qa .chk::before{content:"🔍 严师自查法";color:var(--main)}
.qa .why{background:#f3e5f5}.qa .why::before{content:"初学者常错原因";color:#6a1b9a}
.check{background:#e3f2fd;border:1px solid #90caf9;border-left:5px solid var(--main);border-radius:8px;padding:10px 16px;margin:12px 0}
.check::before{content:"🔍 严师自查法";display:block;font-weight:700;color:var(--main);font-size:13px;margin-bottom:2px}
.pit{background:#ffebee;border-left:5px solid var(--warn);border-radius:8px;padding:8px 16px;margin:10px 0;font-size:14.5px}
.pit::before{content:"⚠ 常见错误";display:block;font-weight:700;color:var(--warn);font-size:13px}
.lv{display:inline-block;font-size:12px;font-weight:700;padding:0 7px;border-radius:4px;background:#263238;color:#fff;margin:0 2px;vertical-align:middle;line-height:19px}
.chain{display:grid;grid-template-columns:repeat(4,1fr);gap:10px;margin:10px 0}
.chain div{background:#fff;border:1px solid var(--line);border-top:4px solid var(--main);border-radius:8px;padding:8px 12px;font-size:14px}
.chain div b{display:block;color:var(--main)}
/* 一周路线 */
.roadmap{display:grid;grid-template-columns:repeat(7,1fr);gap:8px;margin:8px 0}
.roadmap .d{background:#fff;border:1px solid var(--line);border-radius:10px;padding:10px;font-size:13px;display:flex;flex-direction:column;gap:4px;min-height:132px}
.roadmap .d .n{font-weight:700;color:var(--muted);font-size:12px}
.roadmap .d .t{font-weight:700;color:#263238;font-size:14px;line-height:1.45}
.roadmap .d.done{border-color:#81c784;background:#f1f8e9}
.roadmap .d.todo{border-style:dashed;opacity:.85}
.roadmap .d .pill{align-self:flex-start;margin-top:auto}
.roadmap a.d{text-decoration:none;color:inherit}
@media (max-width:960px){.roadmap{grid-template-columns:repeat(4,1fr)}.chain{grid-template-columns:1fr 1fr}}
@media (max-width:560px){.roadmap{grid-template-columns:1fr 1fr}.chain{grid-template-columns:1fr}.say{padding-left:40px;font-size:15px}.say::before{left:8px}}

/* ===== v1.2 笔记 ===== */
.nb{display:inline-flex;align-items:center;gap:2px;margin-left:8px;padding:0 8px;height:22px;border:1px dashed #b0bec5;border-radius:11px;background:#fafbfc;color:#607d8b;font:inherit;font-size:12px;font-weight:500;cursor:pointer;vertical-align:middle;line-height:1;transition:all .15s}
.nb:hover,.nb.active{background:#e3f2fd;border-color:#64b5f6;color:var(--main);border-style:solid}
.nb.has{background:#e8f5e9;border-color:#81c784;border-style:solid;color:var(--ok)}
.nb.alert{background:#fff3e0;border-color:#ffb74d;color:#e65100}
.nb .nb-q{background:#e65100;color:#fff;border-radius:8px;padding:0 5px;font-size:11px;font-weight:700;line-height:16px}
.qa .q .nb,.ex > li .nb{float:right;margin:2px 0 0 8px}
ol.ex > li{position:relative}
.np{background:#fffef8;border:1px solid #ffe082;border-radius:10px;padding:12px 14px;margin:10px 0 18px;box-shadow:0 2px 8px rgba(255,193,7,.12)}
.np-title{font-weight:700;color:#f57f17;margin-bottom:8px;font-size:15px}
.np-sub{font-weight:400;color:var(--muted);font-size:13px;margin-left:6px}
.np-empty{color:var(--muted);font-size:14px;padding:6px 0 10px}
.np-form{border-top:1px dashed #ffe082;margin-top:10px;padding-top:10px}
.np-text{width:100%;min-height:72px;border:1px solid #e0e0e0;border-radius:8px;padding:8px 10px;font:inherit;font-size:14.5px;resize:vertical;background:#fff;display:block}
.np-text:focus{outline:2px solid #90caf9;border-color:#64b5f6}
.np-row{display:flex;flex-wrap:wrap;gap:8px 12px;align-items:center;margin-top:8px;font-size:14px}
.np-row label{display:inline-flex;align-items:center;gap:4px}
.np-row select{font:inherit;font-size:14px;padding:2px 6px;border-radius:5px;border:1px solid #cfd8dc}
.np-row .sp{flex:1}
.np-warn{margin-top:8px;font-size:13px;color:#c62828;background:#ffebee;padding:6px 10px;border-radius:6px}
.ni{background:#fff;border:1px solid var(--line);border-radius:8px;padding:10px 12px;margin:8px 0}
.ni.open-q{border-left:4px solid #e65100}
.ni.done{opacity:.78}
.ni.editing{border-color:#64b5f6;background:#f5f9ff}
.ni-head{display:flex;flex-wrap:wrap;gap:6px 10px;align-items:center;font-size:12.5px;margin-bottom:4px}
.ni-type{font-weight:700;padding:0 7px;border-radius:10px;line-height:18px}
.ni-type.t-question{background:#fff3e0;color:#e65100}
.ni-type.t-insight{background:#e8f5e9;color:#2e7d32}
.ni-type.t-ask{background:#ede7f6;color:#5e35b1}
.ni-status{padding:0 7px;border-radius:10px;line-height:18px}
.ni-status.s-open{background:#eceff1;color:#546e7a}
.ni-status.s-resolved{background:#e0f2f1;color:#00695c}
.ni-time{color:var(--muted)}
.ni-link,.ns-link{font-size:12.5px;margin-left:auto}
.ni-quote{margin:6px 0;padding:6px 12px;border-left:3px solid #ffb300;background:#fff8e1;color:#5d4037;font-size:13.5px}
.ni-body{font-size:14.5px;line-height:1.7;white-space:pre-wrap;word-break:break-word}
.ni-actions{margin-top:6px;display:flex;flex-wrap:wrap;gap:6px}
.ni-actions button,.linkish{font:inherit;font-size:12.5px;padding:2px 10px;border-radius:5px;border:1px solid #cfd8dc;background:#fff;color:#455a64;cursor:pointer}
.ni-actions button:hover{background:#eceff1}
.ni-actions button.danger{color:#c62828;border-color:#ef9a9a}
.ni-actions button.danger:hover{background:#ffebee}
button.linkish{border:0;background:none;color:var(--main);padding:0;text-decoration:underline}
.ys-hl{outline:3px solid #ffca28;outline-offset:3px;border-radius:6px;animation:yshl 6s ease-out}
@keyframes yshl{0%{background:rgba(255,202,40,.35)}70%{background:rgba(255,202,40,.12)}100%{background:transparent}}
.sel-note{display:none;position:absolute;z-index:200;background:#1565c0;color:#fff;border:0;border-radius:20px;padding:6px 14px;font:inherit;font-size:13px;font-weight:600;cursor:pointer;box-shadow:0 4px 14px rgba(21,101,192,.4);white-space:nowrap}
.sel-note:hover{background:#0d47a1}
.term-saved{display:block;font-size:12px;color:var(--muted);margin-top:2px}
.ys-store-warn{background:#c62828;color:#fff;padding:10px 18px;font-size:14px;line-height:1.6}
.ys-store-warn a,.ys-store-warn code{color:#fffde7}
.ys-store-warn .btn{margin-left:8px;background:#fff;color:#c62828}
.ys-toast{position:fixed;left:50%;bottom:28px;transform:translateX(-50%) translateY(20px);background:#263238;color:#fff;padding:8px 18px;border-radius:8px;font-size:14px;opacity:0;pointer-events:none;transition:all .2s;z-index:300;max-width:90vw;box-shadow:0 4px 16px rgba(0,0,0,.25)}
.ys-toast.show{opacity:1;transform:translateX(-50%) translateY(0)}
.ys-toast.err{background:#c62828}
.stats{display:flex;flex-wrap:wrap;gap:10px;margin:10px 0 16px}
.stat{background:#fff;border:1px solid var(--line);border-radius:10px;padding:10px 14px;min-width:110px;text-align:center}
.stat b{display:block;font-size:22px;color:var(--main);line-height:1.2}
.stat.alert b{color:#e65100}
.filters{display:flex;flex-wrap:wrap;gap:8px 12px;align-items:center;margin:8px 0 14px}
.filters input[type=search],.filters select{font:inherit;font-size:14px;padding:5px 10px;border:1px solid var(--line);border-radius:6px;background:#fff}
.filters input[type=search]{min-width:200px;flex:1}
.ng{margin:18px 0 28px}
.ng > h2{margin-top:8px}
.ns{background:#fff;border:1px solid var(--line);border-radius:10px;padding:10px 14px;margin:10px 0}
.ns > h3{margin:0 0 6px;font-size:16px;display:flex;flex-wrap:wrap;align-items:baseline;gap:4px 10px}
.warn-num{color:#e65100}
.tools-bar{display:flex;flex-wrap:wrap;gap:8px;align-items:center;margin:8px 0 14px}
#notes-summary{font-size:14px}
#notes-summary a{font-weight:600}
@media (max-width:720px){
  .nb{margin-left:4px;padding:0 6px}
  .qa .q .nb,.ex > li .nb{float:none;display:inline-flex;margin:4px 0 0 6px}
  .filters input[type=search]{min-width:0;width:100%}
  .ni-head .ni-link{margin-left:0;width:100%}
}
@media print{.nb,.np,.sel-note,.ys-store-warn,.ys-toast{display:none!important}}