/* ============================================
   看懂湖南 · 卡通青少年版样式
   设计语言：糖果配色 + 粗描边 + 硬投影 + 圆角贴纸
   ============================================ */
:root{
  --paper:#fff6e3;          /* 奶油底 */
  --surface:#ffffff;
  --ink:#2d2a32;            /* 卡通描边深色 */
  --muted:#6f6880;
  --red:#ff5d5d;
  --gold:#ffbe0b;
  --green:#3ecf8e;
  --blue:#4aa8ff;
  --purple:#9b7bff;
  --pink:#ff8fab;
  --orange:#ff9f1c;
  --pastel-blue:#e3f2ff;
  --pastel-yellow:#fff3c4;
  --pastel-pink:#ffe3ec;
  --pastel-green:#e2f9ee;
  --line:#2d2a32;
  --shadow:6px 6px 0 rgba(45,42,50,.9);
  --shadow-soft:6px 6px 0 rgba(45,42,50,.14);
  --radius:22px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  background-color:var(--paper);
  /* 奶油底 + 波点纹理，营造卡通手账感 */
  background-image:radial-gradient(rgba(45,42,50,.055) 2.2px,transparent 2.8px);
  background-size:28px 28px;
  color:var(--ink);
  font-family:"Yuanti SC","YouYuan","PingFang SC","Hiragino Sans GB","Microsoft YaHei","Comic Sans MS",sans-serif;
  line-height:1.72;
}
a{color:inherit}
button,input,textarea{font:inherit}
button{cursor:pointer}
::selection{background:var(--gold);color:var(--ink)}

/* ---------- 通用卡通按钮手感：按下时塌陷 ---------- */
.action-btn,.group-toggle,.primary,.secondary,.reveal-btn,.filter-pills button{
  border:2.5px solid var(--ink);
  box-shadow:3px 3px 0 rgba(45,42,50,.9);
  transition:transform .12s ease,box-shadow .12s ease,background .15s ease;
}
.action-btn:active,.group-toggle:active,.primary:active,.secondary:active,.reveal-btn:active,.filter-pills button:active{
  transform:translate(3px,3px);
  box-shadow:0 0 0 rgba(45,42,50,.9);
}

/* ---------- 顶栏 ---------- */
.page{max-width:1440px;margin:auto}
.topbar{position:sticky;top:0;z-index:50;background:rgba(255,252,244,.95);backdrop-filter:blur(10px);border-bottom:3px solid var(--ink)}
.topbar-inner{max-width:1440px;margin:auto;display:flex;align-items:center;gap:18px;padding:10px 28px}
.brand{font-weight:900;color:var(--red);white-space:nowrap;font-size:17px;text-shadow:2px 2px 0 var(--pastel-yellow)}
.topnav{display:flex;gap:6px;overflow:auto;scrollbar-width:none;flex:1}
.topnav a{text-decoration:none;padding:7px 12px;border-radius:999px;font-size:13px;font-weight:700;white-space:nowrap;border:2px solid transparent;transition:.15s}
.topnav a:hover{background:var(--pastel-yellow);border-color:var(--ink);transform:translateY(-1px)}
.top-actions{display:flex;gap:8px}
.action-btn{background:#fff;border-radius:14px;padding:8px 13px;color:var(--ink);font-weight:700}
.action-btn:hover{background:var(--pastel-blue)}

/* ---------- Hero 首屏 ---------- */
.hero{padding:42px 28px 30px;display:grid;grid-template-columns:minmax(0,1.06fr) minmax(360px,.94fr);gap:34px;align-items:center;min-height:620px}
.hero-copy{padding-left:max(0px,calc((100vw - 1384px)/2))}
.kicker{display:inline-flex;align-items:center;gap:8px;background:var(--gold);color:var(--ink);padding:7px 14px;border-radius:999px;font-weight:900;font-size:13px;border:2.5px solid var(--ink);box-shadow:3px 3px 0 rgba(45,42,50,.9);transform:rotate(-1.2deg)}
.hero h1{font-size:clamp(46px,7vw,92px);line-height:1.06;margin:22px 0 12px;letter-spacing:.01em;color:var(--ink);font-weight:900;text-shadow:4px 4px 0 var(--gold)}
.hero h1 span{display:block;color:var(--red);font-size:.42em;letter-spacing:.02em;margin-top:14px;text-shadow:3px 3px 0 var(--pastel-pink)}
.hero-sub{font-size:clamp(18px,2vw,26px);color:#4c4660;max-width:760px;font-weight:600}
.hero-meta{display:flex;flex-wrap:wrap;gap:10px;margin:24px 0}
.hero-meta span{border:2.5px solid var(--ink);background:#fff;padding:8px 14px;border-radius:999px;font-size:14px;font-weight:800;box-shadow:3px 3px 0 rgba(45,42,50,.9)}
.hero-meta span:nth-child(odd){background:var(--pastel-blue);transform:rotate(-1deg)}
.hero-meta span:nth-child(even){background:var(--pastel-pink);transform:rotate(1deg)}
.hero-note{border:2.5px solid var(--ink);border-left:10px solid var(--gold);padding:14px 18px;background:#fff;border-radius:16px;max-width:760px;box-shadow:var(--shadow-soft);font-weight:600}
.hero .stats{padding:0;margin:0;grid-template-columns:repeat(2,1fr);align-content:center}
.hero .progress-card{grid-column:auto;min-height:0}

/* ---------- 数据卡 ---------- */
.stats{display:grid;grid-template-columns:repeat(4,1fr);gap:16px;padding:0 28px 38px}
.stat{background:var(--surface);border:3px solid var(--ink);border-radius:var(--radius);padding:22px;box-shadow:var(--shadow-soft)}
.stat:nth-child(1){background:var(--pastel-yellow);transform:rotate(-.6deg)}
.stat:nth-child(2){background:var(--pastel-blue);transform:rotate(.6deg)}
.stat:nth-child(3){background:var(--pastel-pink);transform:rotate(-.6deg)}
.stat b{display:block;font-size:36px;color:var(--red);line-height:1;font-weight:900}
.stat:nth-child(2) b{color:var(--blue)}
.stat:nth-child(3) b{color:var(--purple)}
.stat span{color:#4c4660;font-size:14px;font-weight:700}
.progress-card{grid-column:span 2;background:var(--pastel-green)}
.progress-card b{color:#1c9e6a}
.progress-track{height:14px;background:#fff;border:2.5px solid var(--ink);border-radius:999px;overflow:hidden;margin-top:14px}
.progress-fill{height:100%;width:0;background:repeating-linear-gradient(-45deg,var(--red) 0 12px,var(--gold) 12px 24px);transition:width .35s ease}

/* ---------- 主体布局与侧栏 ---------- */
.content-shell{display:grid;grid-template-columns:230px minmax(0,1fr);gap:30px;padding:0 28px 80px}
.side{position:sticky;top:80px;align-self:start;background:#fff;border:3px solid var(--ink);border-radius:var(--radius);padding:18px;max-height:calc(100vh - 100px);overflow:auto;box-shadow:var(--shadow-soft)}
.side h2{font-size:15px;margin:0 0 10px;font-weight:900}
.side a{display:block;text-decoration:none;font-size:14px;font-weight:700;padding:7px 10px;border-radius:12px;color:#4c4660;border:2px solid transparent;transition:.15s}
.side a:hover{background:var(--pastel-yellow);color:var(--ink);border-color:var(--ink);transform:translateX(3px)}
main{min-width:0}
.section{margin-bottom:60px;scroll-margin-top:82px}
.section-heading{display:flex;justify-content:space-between;gap:18px;align-items:end;margin-bottom:22px;border-bottom:3px dashed rgba(45,42,50,.35);padding-bottom:14px}
.section-heading h2{font-size:clamp(28px,4vw,44px);margin:2px 0 4px;line-height:1.15;font-weight:900}
.section-heading p{margin:0;color:var(--muted);font-weight:600}
.eyebrow{display:inline-block;font-size:12px;font-weight:900;letter-spacing:.08em;color:var(--ink);background:var(--pastel-pink);border:2px solid var(--ink);border-radius:999px;padding:3px 11px}
.panel{background:var(--surface);border:3px solid var(--ink);border-radius:var(--radius);padding:clamp(18px,3vw,34px);box-shadow:var(--shadow-soft)}

/* ---------- 使用说明 / 价值卡 / 表格 / 图解 ---------- */
.value-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}
.value-card{border:2.5px solid var(--ink);border-radius:18px;padding:20px;box-shadow:var(--shadow-soft);transition:transform .18s ease}
.value-card:nth-child(1){background:var(--pastel-yellow)}
.value-card:nth-child(2){background:var(--pastel-blue)}
.value-card:nth-child(3){background:var(--pastel-green)}
.value-card:hover{transform:translateY(-4px) rotate(-.5deg)}
.value-card h3{margin:0 0 8px;color:var(--red);font-weight:900}
.value-card:nth-child(2) h3{color:var(--blue)}
.value-card:nth-child(3) h3{color:#1c9e6a}
.value-card ul{padding-left:1.1em;margin:0}
.responsive-table{overflow:auto;border:3px solid var(--ink);border-radius:16px;box-shadow:var(--shadow-soft)}
table{width:100%;border-collapse:collapse;background:white}
th,td{padding:13px 15px;border-bottom:2px solid #efe6d2;text-align:left;vertical-align:top}
th{background:var(--blue);color:white;position:sticky;top:0;font-weight:900;border-bottom:3px solid var(--ink)}
tr:nth-child(even) td{background:#fffaf0}
tr:last-child td{border-bottom:0}
.diagram-grid{display:grid;grid-template-columns:1fr;gap:22px}
.diagram{background:white;border-radius:var(--radius);padding:12px;border:3px solid var(--ink);box-shadow:var(--shadow-soft)}
.diagram:nth-child(odd){transform:rotate(-.4deg)}
.diagram:nth-child(even){transform:rotate(.4deg)}
.diagram img{display:block;width:100%;border-radius:14px}
.diagram figcaption{padding:10px 7px 3px;color:var(--muted);font-size:14px;font-weight:700}

/* ---------- 学习工具条 / 搜索 / 筛选 ---------- */
.learning-toolbar{position:sticky;top:63px;z-index:35;background:rgba(255,246,227,.96);backdrop-filter:blur(10px);padding:13px 0;display:grid;grid-template-columns:minmax(220px,1fr) auto;gap:12px;align-items:center}
.searchbox{display:flex;align-items:center;background:white;border:2.5px solid var(--ink);border-radius:999px;padding:0 15px;box-shadow:3px 3px 0 rgba(45,42,50,.9);font-weight:700}
.searchbox input{width:100%;border:0;outline:0;background:transparent;padding:11px 8px}
.filter-pills{display:flex;gap:8px;overflow:auto}
.filter-pills button{background:white;border-radius:999px;padding:8px 14px;white-space:nowrap;font-size:13px;font-weight:800}
.filter-pills button:hover{background:var(--pastel-blue)}
.filter-pills button.active{background:var(--ink);color:#fff;border-color:var(--ink)}

/* ---------- 知识卡 ---------- */
.knowledge-group{scroll-margin-top:130px;margin:30px 0 68px}
.knowledge-group>.section-heading{border-color:var(--group-accent)}
.group-toggle{background:#fff;border-radius:12px;padding:8px 13px;white-space:nowrap;font-weight:800}
.group-toggle:hover{background:var(--pastel-yellow)}
.knowledge-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:18px}
.knowledge-card{
  background:var(--surface);
  border:3px solid var(--ink);
  border-radius:20px;
  padding:19px;
  box-shadow:6px 6px 0 var(--group-accent,var(--gold));
  break-inside:avoid;
  transition:transform .16s ease,box-shadow .16s ease;
}
.knowledge-card:hover{transform:translate(-2px,-3px);box-shadow:8px 9px 0 var(--group-accent,var(--gold))}
.knowledge-card.is-done{opacity:.6;box-shadow:3px 3px 0 rgba(45,42,50,.25)}
.knowledge-card.hidden{display:none}
.card-head{display:grid;grid-template-columns:48px minmax(0,1fr) auto;gap:12px;align-items:start}
.number{width:44px;height:44px;border-radius:14px;background:var(--group-accent,var(--blue));border:2.5px solid var(--ink);display:grid;place-items:center;color:white;font-size:13px;font-weight:900;letter-spacing:.04em;transform:rotate(-3deg);text-shadow:1px 1px 0 rgba(45,42,50,.45)}
.card-title-wrap h3{font-size:18px;margin:3px 0 0;line-height:1.35;font-weight:900}
.card-tags{display:flex;gap:6px;flex-wrap:wrap}
.card-tags span{background:var(--pastel-yellow);color:var(--ink);border:2px solid var(--ink);border-radius:999px;padding:2px 8px;font-size:11px;font-weight:800}
.card-tags span:nth-child(2){background:var(--pastel-pink)}
.done-label{font-size:11px;color:var(--muted);display:flex;flex-direction:column;align-items:center;gap:2px;font-weight:800}
.done-box{width:20px;height:20px;accent-color:var(--green);cursor:pointer}
.core-text{font-size:15px;margin:15px 0 13px}
.source-ref a{color:var(--red);text-decoration:none;font-weight:800}
.source-ref a:hover{text-decoration:underline}
.card-notes{display:grid;grid-template-columns:1fr 1fr;gap:10px}
.card-notes>div{background:#fffaf0;border:2px dashed rgba(45,42,50,.35);border-radius:14px;padding:11px}
.card-notes strong{font-size:12px;color:var(--red);font-weight:900}
.card-notes p{margin:3px 0 0;font-size:13px;color:#4c4660}
.empty-state{display:none;text-align:center;padding:40px;color:var(--muted);font-weight:700}

/* ---------- 练习区 ---------- */
.exercise-intro{display:flex;justify-content:space-between;gap:12px;align-items:center;background:var(--pastel-green);border:3px solid var(--ink);padding:16px 18px;border-radius:18px;margin-bottom:18px;box-shadow:var(--shadow-soft);font-weight:700}
.exercise-actions{display:flex;gap:8px}
.primary{background:var(--red);color:white;border-radius:14px;padding:10px 16px;font-weight:900;text-shadow:1px 1px 0 rgba(45,42,50,.4)}
.primary:hover{background:#ff7070}
.secondary{background:white;border-radius:14px;padding:10px 16px;font-weight:800}
.secondary:hover{background:var(--pastel-blue)}
.question-list{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px}
.question-card,.open-question,.material-card{background:var(--surface);border:3px solid var(--ink);border-radius:20px;padding:20px;break-inside:avoid;box-shadow:var(--shadow-soft)}
.question-card{position:relative;padding-left:60px}
.question-number{position:absolute;left:17px;top:18px;background:var(--blue);border:2.5px solid var(--ink);color:white;border-radius:12px;padding:5px 8px;font-weight:900;transform:rotate(-3deg);text-shadow:1px 1px 0 rgba(45,42,50,.45)}
.question-card h3{margin:0 0 13px;font-size:16px;font-weight:900}
.options{display:grid;gap:8px}
.option{display:grid;grid-template-columns:auto 28px 1fr;gap:7px;align-items:center;padding:9px;border:2px solid rgba(45,42,50,.4);border-radius:14px;cursor:pointer;transition:.14s;font-weight:600}
.option:hover{background:var(--pastel-yellow);border-color:var(--ink);transform:translateX(2px)}
.option-letter{font-weight:900;color:var(--red)}
.question-card.correct{border-color:var(--ink);background:var(--pastel-green)}
.question-card.wrong{border-color:var(--ink);background:var(--pastel-pink)}
.question-feedback{font-weight:900;margin-top:8px}
.explanation{display:none;background:var(--pastel-blue);border:2px dashed rgba(45,42,50,.4);border-radius:12px;padding:10px;margin-top:8px;font-size:13px}
.question-card.checked .explanation{display:block}
.open-list,.material-list{display:grid;gap:16px}
.open-question h3,.material-card h3{margin:0;font-weight:900}
textarea{width:100%;min-height:110px;resize:vertical;border:2.5px solid var(--ink);background:#fffefa;border-radius:14px;padding:12px;margin:12px 0;outline:none;font-weight:600}
textarea:focus{box-shadow:3px 3px 0 var(--blue)}
.reveal-btn{background:var(--pastel-yellow);border-radius:12px;padding:8px 13px;font-weight:800}
.reveal-btn:hover{background:var(--gold)}
.reference-answer{display:none;margin-top:10px;border-left:10px solid var(--gold);border:2.5px solid var(--ink);border-left-width:10px;background:#fffaf0;padding:12px 14px;border-radius:12px}
.reference-answer.show{display:block}
.material-title{display:flex;gap:12px;align-items:center}
.material-title>span{background:var(--red);border:2.5px solid var(--ink);color:white;border-radius:999px;padding:4px 11px;font-size:12px;font-weight:900;text-shadow:1px 1px 0 rgba(45,42,50,.4)}
blockquote{margin:16px 0;background:var(--pastel-blue);border:2.5px solid var(--ink);border-left:10px solid var(--blue);padding:18px;border-radius:14px;font-weight:600}
.material-question{display:block;margin-top:12px}
.material-question span{font-weight:800}
.material-question textarea{min-height:90px}

/* ---------- 研究报告 / 家长页 / 资料来源 ---------- */
.report-sheet{background:white;border:3px solid var(--ink);border-radius:20px;padding:22px;box-shadow:var(--shadow-soft)}
.report-grid{display:grid;grid-template-columns:1fr 1fr;border-left:2.5px solid var(--ink);border-top:2.5px solid var(--ink);border-radius:12px;overflow:hidden}
.report-field{min-height:90px;border-right:2.5px solid var(--ink);border-bottom:2.5px solid var(--ink);padding:12px;background:#fff}
.report-field.wide{grid-column:1/-1;min-height:125px}
.report-field strong{display:block;color:var(--red);margin-bottom:6px;font-weight:900}
.lines{height:56px;background:repeating-linear-gradient(to bottom,transparent 0,transparent 25px,#cfe3f7 26px)}
.parent-callout{background:var(--pastel-pink);border:3px solid var(--ink);border-left:12px solid var(--red);border-radius:18px;padding:18px 20px;margin-bottom:18px;box-shadow:var(--shadow-soft);font-weight:600}
.source-list{list-style:none;padding:0;margin:0;display:grid;gap:10px}
.source-list li{display:grid;grid-template-columns:46px 1fr;gap:12px;padding:12px;border-bottom:2px dashed rgba(45,42,50,.25)}
.source-list li>span{background:var(--purple);border:2.5px solid var(--ink);color:white;border-radius:12px;height:34px;display:grid;place-items:center;font-weight:900;text-shadow:1px 1px 0 rgba(45,42,50,.4)}
.source-list a{display:block;color:var(--blue);word-break:break-all;font-size:13px;margin-top:3px;font-weight:700}
.boundary{display:grid;grid-template-columns:repeat(2,1fr);gap:12px}
.boundary div{background:var(--pastel-green);border:2.5px solid var(--ink);padding:15px;border-radius:16px;font-weight:600}
footer{text-align:center;color:var(--muted);padding:24px 20px 60px;font-weight:700}
.backtop{position:fixed;right:18px;bottom:18px;width:48px;height:48px;border-radius:50%;border:3px solid var(--ink);background:var(--red);color:white;font-weight:900;box-shadow:4px 4px 0 rgba(45,42,50,.9);z-index:40;transition:transform .14s ease,box-shadow .14s ease}
.backtop:hover{transform:translateY(-3px)}
.backtop:active{transform:translate(2px,2px);box-shadow:0 0 0 rgba(45,42,50,.9)}

/* ---------- 密码解锁 ---------- */
main.locked > section.locked-section{display:none}
main.locked .knowledge-card.locked-card{display:none}
.wait-unlock-card{
  display:grid;
  place-items:center;
  text-align:center;
  background:var(--pastel-yellow);
  border:3px dashed var(--ink);
  opacity:.95;
}
.wait-unlock-card .lock-icon{font-size:46px;margin-bottom:4px}
.wait-unlock-card p{margin:4px 0 0;font-weight:900}
.wait-unlock-card p.hint{font-size:13px;color:var(--muted);font-weight:700}
.unlock-box{display:grid;place-items:center;min-height:70vh;padding:28px}
.unlock-inner{max-width:420px;width:100%;background:var(--surface);border:3px solid var(--ink);border-radius:var(--radius);padding:34px;text-align:center;box-shadow:var(--shadow);transform:rotate(-.5deg)}
.lock-icon{font-size:56px;margin-bottom:12px;filter:drop-shadow(2px 2px 0 rgba(45,42,50,.2))}
.unlock-inner h2{margin:0 0 10px;font-size:24px;font-weight:900}
.unlock-inner p{margin:0 0 22px;color:var(--muted);font-weight:700}
#unlockForm{display:grid;gap:14px}
#passwordInput{width:100%;border:2.5px solid var(--ink);border-radius:14px;padding:13px 16px;background:#fffefa;font-weight:800;outline:none;box-shadow:3px 3px 0 rgba(45,42,50,.9)}
#passwordInput:focus{box-shadow:3px 3px 0 var(--blue)}
.unlock-btn{background:var(--red);color:#fff;border:2.5px solid var(--ink);border-radius:14px;padding:13px 18px;font-weight:900;font-size:16px;cursor:pointer;box-shadow:3px 3px 0 rgba(45,42,50,.9);text-shadow:1px 1px 0 rgba(45,42,50,.4);transition:transform .12s ease,box-shadow .12s ease}
.unlock-btn:hover{background:#ff7070}
.unlock-btn:active{transform:translate(3px,3px);box-shadow:0 0 0 rgba(45,42,50,.9)}
.unlock-message{min-height:22px;margin-top:12px;font-weight:800;color:var(--red)}

/* ---------- 响应式 ---------- */
@media(max-width:1050px){
  .hero{grid-template-columns:1fr;min-height:auto}
  .content-shell{grid-template-columns:1fr}
  .side{display:none}
  .knowledge-grid,.question-list{grid-template-columns:1fr}
}
@media(max-width:720px){
  .topbar-inner{padding:8px 12px}
  .brand{display:none}
  .top-actions .action-btn:first-child{display:none}
  .hero{padding:28px 16px 24px;gap:20px}
  .hero h1{font-size:48px;text-shadow:3px 3px 0 var(--gold)}
  .stats{grid-template-columns:1fr 1fr;padding:0 16px 28px}
  .progress-card{grid-column:1/-1}
  .content-shell{padding:0 14px 60px}
  .value-grid{grid-template-columns:1fr}
  .learning-toolbar{top:55px;grid-template-columns:1fr;padding:9px 0}
  .section-heading{align-items:start}
  .group-toggle{font-size:12px}
  .card-notes{grid-template-columns:1fr}
  .report-grid{grid-template-columns:1fr}
  .report-field.wide{grid-column:auto}
  .boundary{grid-template-columns:1fr}
  .exercise-intro{align-items:flex-start;flex-direction:column}
  .question-card{padding-left:18px;padding-top:58px}
  .question-number{top:15px}
}

/* ---------- 打印 ---------- */
@media print{
  @page{size:A4;margin:13mm}
  body{background:white;font-size:10.5pt}
  .topbar,.side,.learning-toolbar,.group-toggle,.backtop,.top-actions,.done-label,.exercise-actions,.reveal-btn{display:none!important}
  .hero{min-height:0;padding:0;grid-template-columns:1fr 1fr;page-break-after:always}
  .hero h1{font-size:42pt}
  .stats{padding:0;page-break-after:always}
  .stat,.panel,.knowledge-card,.question-card,.open-question,.material-card,.report-sheet,.value-card,.diagram{box-shadow:none}
  .content-shell{display:block;padding:0}
  .section,.knowledge-group{margin-bottom:24px}
  .knowledge-grid{grid-template-columns:1fr 1fr;gap:8px}
  .knowledge-card{padding:10px;border-radius:9px;font-size:9pt;border-width:2px}
  .knowledge-card:hover{transform:none}
  .card-head{grid-template-columns:34px 1fr}
  .number{width:31px;height:31px;border-radius:7px;font-size:8pt}
  .card-title-wrap h3{font-size:11pt}
  .core-text{font-size:9pt;margin:8px 0}
  .card-notes{gap:6px}
  .card-notes>div{padding:7px}
  .card-notes p{font-size:8pt}
  .section-heading h2{font-size:23pt}
  .question-list{grid-template-columns:1fr 1fr}
  .question-card,.open-question,.material-card{padding:11px}
  textarea{border:0;border-bottom:1px solid #aaa;border-radius:0;min-height:70px}
  .explanation,.reference-answer{display:block!important}
  a{text-decoration:none}
  .source-list a{font-size:8pt}
}