:root{
  --bg:#F7F6F2;
  --surface:#FFFFFF;
  --surface-2:#FBFAF7;
  --ink:#1B2A4A;
  --ink-soft:#3B4A6B;
  --muted:#6B6B63;
  --border:#E4E1D8;
  --accent:#B8863B;
  --accent-soft:#F3E7D2;
  --good:#2E7D5B;
  --good-bg:#E8F3EC;
  --bad:#C0392B;
  --bad-bg:#FBEAE8;
  --radius:10px;
  --serif:'Noto Serif TC', serif;
  --sans:'Noto Sans TC', -apple-system, BlinkMacSystemFont, sans-serif;
}

*{box-sizing:border-box;}
html,body{margin:0;padding:0;}
body{
  background:var(--bg);
  color:var(--ink);
  font-family:var(--sans);
  line-height:1.75;
  -webkit-font-smoothing:antialiased;
}
a{color:inherit;text-decoration:none;}
button{font-family:inherit;cursor:pointer;}

/* ---------- Header ---------- */
.site-header{
  position:sticky; top:0; z-index:40;
  background:rgba(247,246,242,0.92);
  backdrop-filter:blur(6px);
  border-bottom:1px solid var(--border);
}
.header-inner{
  max-width:1180px; margin:0 auto; padding:12px 20px;
  display:flex; align-items:center; justify-content:space-between; gap:16px;
}
.brand{display:flex; align-items:center; gap:10px;}
.brand-mark{
  width:36px;height:36px;border-radius:8px;
  background:var(--ink); color:var(--accent-soft);
  display:flex;align-items:center;justify-content:center;
  font-family:var(--serif); font-weight:900; font-size:18px;
  flex-shrink:0;
}
.brand-text{display:flex;flex-direction:column;line-height:1.25;}
.brand-text strong{font-family:var(--serif); font-size:16px; font-weight:700;}
.brand-text small{color:var(--muted); font-size:11px; letter-spacing:.02em;}
.header-actions{display:flex; gap:8px; flex-wrap:wrap;}
.ghost-btn{
  background:var(--surface); border:1px solid var(--border); color:var(--ink-soft);
  padding:7px 12px; border-radius:20px; font-size:13px; font-weight:500;
  transition:.15s;
}
.ghost-btn:hover{border-color:var(--accent); color:var(--ink);}

/* ---------- App shell / layout ---------- */
.app-shell{max-width:1180px; margin:0 auto; padding:24px 20px 100px;}

.hero{
  padding:40px 8px 28px; text-align:center;
}
.hero .eyebrow{
  display:inline-block; font-size:12px; letter-spacing:.12em; color:var(--accent);
  border:1px solid var(--accent); border-radius:20px; padding:4px 12px; margin-bottom:16px;
}
.hero h1{
  font-family:var(--serif); font-size:32px; font-weight:900; margin:0 0 10px;
  color:var(--ink);
}
.hero p{color:var(--muted); max-width:620px; margin:0 auto; font-size:15px;}

.course-grid{
  display:grid; grid-template-columns:repeat(auto-fill,minmax(260px,1fr));
  gap:16px; margin-top:28px;
}
.chapter-card{
  background:var(--surface); border:1px solid var(--border); border-radius:var(--radius);
  padding:20px; display:flex; flex-direction:column; gap:10px;
  transition:.18s; position:relative; overflow:hidden;
}
.chapter-card:hover{border-color:var(--accent); transform:translateY(-2px); box-shadow:0 8px 20px rgba(27,42,74,0.08);}
.chapter-card .no{
  font-family:var(--serif); font-size:13px; color:var(--accent); font-weight:700; letter-spacing:.05em;
}
.chapter-card h3{font-family:var(--serif); font-size:17px; margin:0; color:var(--ink);}
.chapter-card .meta{font-size:12px; color:var(--muted); display:flex; gap:10px; flex-wrap:wrap;}
.chapter-card .progress-bar{height:5px; border-radius:6px; background:var(--border); overflow:hidden;}
.chapter-card .progress-fill{height:100%; background:var(--accent); border-radius:6px;}

/* ---------- Chapter layout ---------- */
.chapter-layout{display:grid; grid-template-columns:220px 1fr; gap:28px; align-items:start;}
.chapter-sidebar{
  position:sticky; top:76px; background:var(--surface); border:1px solid var(--border);
  border-radius:var(--radius); padding:16px; max-height:calc(100vh - 100px); overflow:auto;
}
.chapter-sidebar h4{font-family:var(--serif); font-size:13px; margin:0 0 10px; color:var(--muted);}
.chapter-sidebar ul{list-style:none; margin:0; padding:0; display:flex; flex-direction:column; gap:2px;}
.chapter-sidebar a{
  display:block; font-size:13px; padding:6px 8px; border-radius:6px; color:var(--ink-soft);
}
.chapter-sidebar a:hover{background:var(--accent-soft); color:var(--ink);}
.chapter-sidebar a.sub{padding-left:18px; font-size:12.5px; color:var(--muted);}

.chapter-main{min-width:0;}
.chapter-head{
  border-bottom:2px solid var(--ink); padding-bottom:16px; margin-bottom:24px;
}
.chapter-head .no{font-family:var(--serif); color:var(--accent); font-weight:700; font-size:13px;}
.chapter-head h1{font-family:var(--serif); font-size:26px; margin:8px 0; color:var(--ink);}
.chapter-head .regdate{font-size:12px; color:var(--muted);}
.chapter-toolbar{display:flex; gap:8px; flex-wrap:wrap; margin-top:14px;}
.chip-btn{
  border:1px solid var(--border); background:var(--surface); color:var(--ink-soft);
  border-radius:20px; padding:6px 13px; font-size:12.5px; font-weight:500;
}
.chip-btn:hover{border-color:var(--accent);}
.chip-btn.active{background:var(--ink); color:#fff; border-color:var(--ink);}

/* ---------- Content blocks ---------- */
.block-h2{font-family:var(--serif); font-size:21px; margin:36px 0 14px; color:var(--ink); scroll-margin-top:90px;}
.block-h3{font-family:var(--serif); font-size:16.5px; margin:22px 0 10px; color:var(--ink-soft); scroll-margin-top:90px;}
.block-h4{font-size:13px; margin:22px 0 8px; color:var(--accent); font-weight:700; letter-spacing:.04em;}
.block-p{margin:0 0 14px; font-size:14.5px; color:#2C3550;}
.block-list{margin:0 0 14px; padding-left:22px; font-size:14.5px; color:#2C3550;}
.block-list li{margin-bottom:4px;}

.block-table-wrap{overflow-x:auto; margin:0 0 18px; border:1px solid var(--border); border-radius:var(--radius);}
table.block-table{width:100%; border-collapse:collapse; font-size:13.5px;}
table.block-table th, table.block-table td{
  border-bottom:1px solid var(--border); padding:9px 12px; text-align:left; vertical-align:top;
}
table.block-table th{background:var(--surface-2); font-weight:700; color:var(--ink);}
table.block-table tr:last-child td{border-bottom:none;}

.reg-note{
  background:var(--accent-soft); border-left:4px solid var(--accent);
  border-radius:6px; padding:12px 16px; margin:0 0 18px; font-size:13.5px;
}
.reg-note .rn-title{font-weight:700; color:#7A5A1E; margin-bottom:4px; font-size:13px;}
.reg-note .rn-title::before{content:"📌 最新法規檢核｜";}

/* ---------- Quiz ---------- */
.quiz-card{
  background:var(--surface); border:1px solid var(--border); border-radius:var(--radius);
  padding:18px 20px; margin:0 0 18px;
}
.quiz-card .q-meta{display:flex; justify-content:space-between; align-items:center; margin-bottom:8px;}
.quiz-tag{font-size:11px; color:var(--muted); font-weight:600;}
.diff-badge{font-size:11px; padding:2px 9px; border-radius:12px; font-weight:700;}
.diff-easy{background:var(--good-bg); color:var(--good);}
.diff-medium{background:var(--accent-soft); color:#7A5A1E;}
.diff-hard{background:var(--bad-bg); color:var(--bad);}
.quiz-q{font-size:14.5px; font-weight:500; margin-bottom:12px; color:var(--ink);}
.quiz-options{display:flex; flex-direction:column; gap:8px;}
.quiz-opt{
  text-align:left; border:1px solid var(--border); background:var(--surface-2);
  border-radius:8px; padding:9px 13px; font-size:13.5px; color:var(--ink-soft);
  display:flex; gap:8px;
}
.quiz-opt:hover{border-color:var(--accent);}
.quiz-opt .letter{font-weight:700; color:var(--accent);}
.quiz-opt.correct{background:var(--good-bg); border-color:var(--good); color:var(--good);}
.quiz-opt.wrong{background:var(--bad-bg); border-color:var(--bad); color:var(--bad);}
.quiz-opt.disabled-choice{opacity:.55; cursor:default;}
.quiz-explain{
  margin-top:12px; padding:12px 14px; border-radius:8px; font-size:13.5px;
  background:var(--surface-2); border:1px dashed var(--border);
}
.quiz-explain.show-correct{border-color:var(--good);}
.quiz-explain.show-wrong{border-color:var(--bad);}

/* ---------- QA / Case / Essay ---------- */
.study-card{
  border:1px solid var(--border); border-radius:var(--radius); padding:20px;
  margin:0 0 18px; background:var(--surface-2);
}
.study-card .tag{
  display:inline-block; font-size:11px; font-weight:700; letter-spacing:.04em;
  color:var(--accent); background:var(--accent-soft); padding:3px 10px; border-radius:12px;
  margin-bottom:10px;
}
.study-card .prompt{font-size:14.5px; font-weight:500; margin-bottom:8px; white-space:pre-line;}
.study-card .scenario{font-size:13.5px; color:var(--ink-soft); margin-bottom:10px; white-space:pre-line;}
.study-card textarea{
  width:100%; min-height:90px; border:1px solid var(--border); border-radius:8px;
  padding:10px; font-family:inherit; font-size:13.5px; resize:vertical; margin-bottom:10px;
  background:#fff;
}
.reveal-btn{
  background:var(--ink); color:#fff; border:none; border-radius:20px;
  padding:8px 16px; font-size:12.5px; font-weight:600;
}
.reveal-answer{
  margin-top:12px; padding:14px; border-radius:8px; background:#fff;
  border:1px solid var(--border); font-size:13.5px; white-space:pre-line; display:none;
}
.reveal-answer.show{display:block;}
.study-card .analysis-block{font-size:13.5px; color:var(--ink-soft); white-space:pre-line; margin-bottom:10px;}
.scoring-table{margin-top:10px;}

/* ---------- Review block ---------- */
.review-wrap{
  display:grid; grid-template-columns:1fr 1fr; gap:16px; margin:20px 0 24px;
}
.review-col{
  border-radius:var(--radius); padding:18px 20px; border:1px solid var(--border);
}
.review-col.must{background:#F0F6F2; border-color:#CFE3D6;}
.review-col.trap{background:#FBEFEC; border-color:#F1D3CB;}
.review-col h4{font-family:var(--serif); font-size:14.5px; margin:0 0 10px;}
.review-col.must h4{color:var(--good);}
.review-col.trap h4{color:var(--bad);}
.review-col ol{margin:0; padding-left:20px; font-size:13.5px;}
.review-col li{margin-bottom:6px;}

.chapter-regcheck{
  font-size:12px; color:var(--muted); border-top:1px solid var(--border);
  padding-top:12px; margin-top:20px;
}

/* ---------- Practice tools ---------- */
.practice-panel{
  border:1px solid var(--border); background:var(--surface); border-radius:var(--radius);
  padding:16px 18px; margin-bottom:20px; display:flex; align-items:center; justify-content:space-between;
  flex-wrap:wrap; gap:12px;
}
.practice-panel .p-left{font-size:13px; color:var(--muted);}
.practice-panel .p-actions{display:flex; gap:8px; flex-wrap:wrap;}

.add-question-form{
  border:1px dashed var(--border); border-radius:var(--radius); padding:16px 18px; margin-bottom:20px;
}
.add-question-form input, .add-question-form select, .add-question-form textarea{
  width:100%; padding:8px 10px; border:1px solid var(--border); border-radius:6px;
  font-family:inherit; font-size:13px; margin-bottom:8px; background:#fff;
}
.aq-grid{display:grid; grid-template-columns:1fr 1fr; gap:8px;}
.primary-btn{
  background:var(--ink); color:#fff; border:none; border-radius:20px; padding:9px 18px;
  font-size:13px; font-weight:600;
}
.primary-btn:hover{background:var(--ink-soft);}

/* ---------- Bottom nav ---------- */
.bottom-nav{
  position:sticky; bottom:0; left:0; right:0; margin-top:36px;
  background:rgba(255,255,255,0.95); backdrop-filter:blur(6px);
  border-top:1px solid var(--border); border-radius:var(--radius) var(--radius) 0 0;
  display:flex; justify-content:space-between; align-items:center; padding:12px 18px;
  font-size:13px; box-shadow:0 -4px 16px rgba(27,42,74,0.06);
}
.bottom-nav a{color:var(--ink-soft); font-weight:600;}
.bottom-nav a:hover{color:var(--accent);}
.bottom-nav .center-link{color:var(--accent);}

/* ---------- Modal / toast ---------- */
.modal{
  position:fixed; inset:0; background:rgba(27,42,74,0.45); display:flex;
  align-items:center; justify-content:center; z-index:100; padding:20px;
}
.modal.hidden{display:none;}
.modal-card{background:#fff; border-radius:14px; max-width:520px; width:100%; max-height:80vh; overflow:auto;}
.modal-head{display:flex; justify-content:space-between; align-items:center; padding:18px 22px; border-bottom:1px solid var(--border);}
.modal-head h3{font-family:var(--serif); margin:0; font-size:17px;}
.icon-btn{background:none; border:none; font-size:16px; color:var(--muted);}
.modal-body{padding:18px 22px; font-size:13.5px;}
.modal-foot{padding:14px 22px; border-top:1px solid var(--border); text-align:right;}
.danger-btn{background:var(--bad-bg); color:var(--bad); border:1px solid var(--bad); border-radius:20px; padding:8px 16px; font-size:12.5px; font-weight:600;}

.stat-row{display:flex; justify-content:space-between; padding:8px 0; border-bottom:1px solid var(--border); font-size:13px;}
.stat-row:last-child{border-bottom:none;}

.toast{
  position:fixed; bottom:24px; left:50%; transform:translateX(-50%);
  background:var(--ink); color:#fff; padding:10px 20px; border-radius:20px;
  font-size:13px; z-index:200; box-shadow:0 6px 18px rgba(0,0,0,0.2);
}
.toast.hidden{display:none;}

/* ---------- Responsive ---------- */
@media (max-width: 860px){
  .chapter-layout{grid-template-columns:1fr;}
  .chapter-sidebar{position:static; max-height:none;}
  .review-wrap{grid-template-columns:1fr;}
  .aq-grid{grid-template-columns:1fr;}
  .header-inner{flex-direction:column; align-items:flex-start; gap:10px;}
}
@media (max-width: 500px){
  .hero h1{font-size:24px;}
  .chapter-head h1{font-size:21px;}
}