/* ============================================================
 * 建筑水电工程计价 · AI 赋能课程平台 — Premium Style
 * 玻璃拟态 + 渐变 + 磁吸 + 暗色模式（light/dark/system）
 * ============================================================ */

:root {
  --bg: #eef2f7;
  --bg-2: #e3e9f2;
  --card: rgba(255, 255, 255, 0.78);
  --card-solid: #ffffff;
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --accent: #f59e0b;
  --accent-2: #06b6d4;
  --text: #1f2933;
  --muted: #64748b;
  --border: rgba(15, 23, 42, 0.08);
  --glass-border: rgba(255, 255, 255, 0.6);
  --shadow: 0 10px 30px rgba(15, 23, 42, 0.10);
  --radius: 16px;
  --radius-sm: 10px;
  --grad-hero: linear-gradient(135deg, #2563eb 0%, #06b6d4 100%);
  --grad-soft: linear-gradient(135deg, rgba(37,99,235,.12), rgba(6,182,212,.12));
}
[data-theme="dark"] {
  --bg: #0b1220;
  --bg-2: #0f1830;
  --card: rgba(20, 30, 50, 0.62);
  --card-solid: #131c30;
  --primary: #5b8cff;
  --primary-dark: #3b6fe0;
  --accent: #fbbf24;
  --accent-2: #22d3ee;
  --text: #e6edf6;
  --muted: #93a4bd;
  --border: rgba(255, 255, 255, 0.10);
  --glass-border: rgba(255, 255, 255, 0.12);
  --shadow: 0 10px 36px rgba(0, 0, 0, 0.45);
  --grad-hero: linear-gradient(135deg, #1e3a8a 0%, #0e7490 100%);
  --grad-soft: linear-gradient(135deg, rgba(91,140,255,.16), rgba(34,211,238,.14));
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: "PingFang SC", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  background: radial-gradient(1200px 600px at 80% -10%, var(--grad-soft), transparent 60%), var(--bg);
  color: var(--text); line-height: 1.65; min-height: 100vh;
  transition: background .4s ease, color .4s ease;
}
a { color: var(--primary); }
code { background: rgba(127,127,127,.15); padding: 1px 6px; border-radius: 6px; font-size: 12px; }

/* ---------- 顶栏 ---------- */
.topbar {
  position: sticky; top: 0; z-index: 30;
  display: flex; align-items: center; gap: 16px;
  padding: 12px 22px;
  background: var(--card); backdrop-filter: blur(18px) saturate(160%);
  border-bottom: 1px solid var(--border);
}
.brand { font-weight: 800; font-size: 17px; letter-spacing: .2px; white-space: nowrap; }
.brand .dot { color: var(--accent); }
.brand span { color: var(--primary); }
.nav { display: flex; gap: 4px; flex-wrap: wrap; }
.nav a {
  padding: 8px 14px; cursor: pointer; border-radius: 999px; color: var(--muted);
  font-size: 14px; text-decoration: none; transition: .2s; white-space: nowrap;
}
.nav a:hover { background: var(--grad-soft); color: var(--primary); }
.nav a.active { background: var(--grad-hero); color: #fff; box-shadow: 0 6px 16px rgba(37,99,235,.35); }
.auth { margin-left: auto; display: flex; align-items: center; gap: 10px; }

/* ---------- 按钮 ---------- */
.btn { border: none; border-radius: 999px; padding: 9px 18px; cursor: pointer; font-size: 14px; font-weight: 600; transition: transform .18s cubic-bezier(.16,1,.3,1), box-shadow .18s, background .2s; }
.btn-primary { background: var(--grad-hero); color: #fff; box-shadow: 0 8px 20px rgba(37,99,235,.32); }
.btn-primary:hover { transform: translateY(-2px) scale(1.03); box-shadow: 0 12px 26px rgba(37,99,235,.42); }
.btn-ghost { background: transparent; color: var(--text); border: 1px solid var(--border); }
.btn-ghost:hover { background: var(--grad-soft); }
.btn-accent { background: linear-gradient(135deg, var(--accent), #f97316); color: #fff; }
.btn-sm { padding: 6px 12px; font-size: 13px; }
.btn:active { transform: translateY(0) scale(.98); }

/* 磁吸效果基类 */
.magnetic { transition: transform .2s cubic-bezier(.16,1,.3,1); }
.magnetic:hover { transform: translateY(-2px) scale(1.04); }

/* ---------- 容器 / 视图 ---------- */
.container { max-width: 1180px; margin: 26px auto; padding: 0 20px 60px; }
.view { display: none; animation: fade .32s cubic-bezier(.16,1,.3,1); will-change: opacity, transform; }
.view.active { display: block; }
@keyframes fade { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }
.sec-title { font-size: 21px; margin: 6px 0 14px; display: flex; align-items: center; gap: 10px; color: var(--primary); font-weight: 800; letter-spacing: .3px; }
.sec-title::before { content: ""; width: 5px; height: 22px; border-radius: 4px; background: var(--grad-hero); display: inline-block; }
.hint { color: var(--muted); font-size: 13.5px; margin: -6px 0 16px; }

/* ---------- 玻璃卡片 ---------- */
.glass {
  background: var(--card); backdrop-filter: blur(20px) saturate(160%);
  border: 1px solid var(--glass-border); border-radius: var(--radius);
  box-shadow: var(--shadow); padding: 20px;
}

/* ---------- Hero ---------- */
.hero {
  position: relative; overflow: hidden; border-radius: 22px; padding: 38px 34px;
  background: var(--grad-hero); color: #fff; box-shadow: 0 18px 50px rgba(37,99,235,.30);
  display: grid; grid-template-columns: 1.1fr 0.9fr; gap: 30px; align-items: center;
}
.hero::after { content: ""; position: absolute; right: -60px; top: -60px; width: 260px; height: 260px; background: radial-gradient(circle, rgba(255,255,255,.25), transparent 70%); }
.hero h1 { margin: 0 0 8px; font-size: 34px; letter-spacing: .5px; }
.hero .subtitle { margin: 0; opacity: .94; max-width: 560px; line-height: 1.7; }
.hero-right { position: relative; z-index: 1; }
.hero-stats { display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px; margin-top: 0; }
.hero-stats .stat { background: rgba(255,255,255,.16); border: 1px solid rgba(255,255,255,.25); border-radius: 14px; padding: 16px 14px; min-width: 0; text-align: center; }
.hero-stats b { display: block; font-size: 26px; line-height: 1.2; }
.hero-stats span { font-size: 13px; opacity: .9; }
.mooc-link { display: inline-flex; align-items: center; gap: 8px; margin-top: 20px; background: rgba(255,255,255,.16); border: 1px solid rgba(255,255,255,.3); color: #fff; padding: 9px 16px; border-radius: 999px; text-decoration: none; font-size: 14px; transition: .2s; }
.mooc-link:hover { background: rgba(255,255,255,.28); transform: translateY(-1px); }

/* ---------- 模块 / 资源卡片 ---------- */
.grid { display: grid; gap: 16px; }
.grid.cols-3 { grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); }
.grid.cols-2 { grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); }
.module-card { cursor: pointer; transition: transform .2s cubic-bezier(.16,1,.3,1), box-shadow .2s; }
.module-card:hover { transform: translateY(-4px); box-shadow: 0 16px 40px rgba(37,99,235,.18); }
.module-card h3 { margin: 0 0 10px; font-size: 16.5px; display: inline-block; background: var(--grad-soft); color: var(--text); padding: 7px 14px; border-radius: 12px; border: 1px solid var(--border); }
.module-card .meta { color: var(--muted); font-size: 13px; }
.module-card .bar { height: 7px; border-radius: 999px; background: rgba(127,127,127,.18); margin-top: 12px; overflow: hidden; }
.module-card .bar > i { display: block; height: 100%; background: var(--grad-hero); border-radius: 999px; transition: width .6s ease; }

.res-card { display: flex; flex-direction: column; gap: 8px; transition: transform .18s, box-shadow .18s; cursor: pointer; }
.res-card:hover { transform: translateY(-3px); box-shadow: 0 14px 34px rgba(15,23,42,.14); }
.res-card .tag { font-size: 12px; padding: 2px 9px; border-radius: 999px; background: var(--grad-soft); color: var(--primary); align-self: flex-start; }
.res-card .tag.orig { background: rgba(16,185,129,.16); color: #059669; }
.res-card .tag.ref { background: rgba(245,158,11,.16); color: #b45309; }
.res-card .tag.ai { background: rgba(139,92,246,.16); color: #7c3aed; }
.res-card h4 { margin: 2px 0; font-size: 15px; }
.res-card p { margin: 0; color: var(--muted); font-size: 13px; }
.res-card .done { color: #059669; font-size: 12px; font-weight: 600; }

/* ---------- 过滤条 ---------- */
.filter-bar { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 0; }
.filter-bar button { border: 1px solid var(--border); background: var(--card); border-radius: 999px; padding: 6px 14px; cursor: pointer; font-size: 13px; color: var(--text); transition: .18s; }
.filter-bar button:hover { border-color: var(--primary); }
.filter-bar button.active { background: var(--grad-hero); color: #fff; border-color: transparent; }

/* 资源中心 · 两级导航明确区分（一级：教学模块 / 二级：资源类型） */
.res-nav { margin-bottom: 22px; display: flex; flex-direction: column; gap: 12px; }
.res-nav-level { display: flex; align-items: center; gap: 14px; flex-wrap: wrap; }
.res-nav-label { display: inline-flex; align-items: center; gap: 7px; font-size: 13px; font-weight: 800; color: var(--text); white-space: nowrap; flex: none; }
.res-nav-label .rf-accent { width: 4px; height: 15px; border-radius: 3px; display: inline-block; }
.res-nav-label.mod .rf-accent { background: var(--primary); }
.res-nav-label.type .rf-accent { background: var(--muted); }
.res-nav-level.mod { padding: 12px 14px; background: var(--card); border: 1px solid var(--border); border-left: 4px solid var(--primary); border-radius: 14px; box-shadow: 0 6px 20px rgba(37, 99, 235, .07); }
.res-nav-level.type { padding: 10px 14px; background: var(--grad-soft); border-radius: 12px; }
.mod-bar { align-items: center; }
.mod-bar button { white-space: nowrap; }
.mod-bar .mod-main { border-color: rgba(37, 99, 235, .4); }
.mod-bar .mod-main.active { background: var(--grad-hero); color: #fff; border-color: transparent; }
.mod-bar .mod-extra { border-style: dashed; border-color: rgba(139, 92, 246, .5); color: var(--muted); background: rgba(139, 92, 246, .07); }
.mod-bar .mod-extra.active { background: linear-gradient(135deg, #8b5cf6, #6d28d9); color: #fff; border-color: transparent; }
.mod-sep { width: 1px; align-self: stretch; margin: 2px 6px; background: var(--border); }
/* 二级导航（资源类型）改用描边高亮，与一级填充高亮形成明确层级差异 */
.type-bar button { font-size: 12.5px; padding: 5px 12px; }
.type-bar button.active { background: transparent; color: var(--primary); border-color: var(--primary); font-weight: 700; box-shadow: inset 0 0 0 1px var(--primary); }

/* ---------- 表单 ---------- */
.field { margin-bottom: 14px; }
.field label { display: block; font-size: 13.5px; color: var(--muted); margin-bottom: 6px; }
input[type=text], input[type=password], input[type=number], textarea, select {
  width: 100%; padding: 11px 13px; border: 1px solid var(--border); border-radius: var(--radius-sm);
  background: var(--card-solid); color: var(--text); font-size: 14px; font-family: inherit; transition: border .2s, box-shadow .2s;
}
input:focus, textarea:focus, select:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px rgba(37,99,235,.18); }
textarea { resize: vertical; min-height: 80px; }

/* ---------- 模态框 ---------- */
.modal { position: fixed; inset: 0; background: rgba(8,12,22,.5); backdrop-filter: blur(4px); display: flex; align-items: center; justify-content: center; z-index: 50; animation: fade .2s; }
.modal[hidden] { display: none; }
.modal-box { background: var(--card-solid); border-radius: 20px; padding: 26px; width: 380px; max-width: 92vw; box-shadow: var(--shadow); border: 1px solid var(--border); max-height: 90vh; overflow-y: auto; overscroll-behavior: contain; }
.modal-box h3 { margin: 0 0 4px; }
.role-tabs { display: flex; gap: 6px; margin: 14px 0; }
.role-tabs button { flex: 1; padding: 9px; border-radius: 12px; border: 1px solid var(--border); background: transparent; cursor: pointer; font-size: 13.5px; color: var(--text); transition: .18s; }
.role-tabs button.active { background: var(--grad-hero); color: #fff; border-color: transparent; }
.err { color: #ef4444; font-size: 13px; margin-top: 8px; }

/* ---------- AI 学伴 ---------- */
.ai-layout { display: grid; grid-template-columns: 1fr; gap: 16px; }
.chat-box { height: 460px; overflow-y: auto; display: flex; flex-direction: column; gap: 12px; padding: 6px 2px; }
.bubble { max-width: 80%; padding: 11px 14px; border-radius: 14px; font-size: 14px; line-height: 1.6; }
.bubble.user { align-self: flex-end; background: var(--grad-hero); color: #fff; border-bottom-right-radius: 4px; }
.bubble.ai { align-self: flex-start; background: var(--card); border: 1px solid var(--border); border-bottom-left-radius: 4px; }
.bubble.ai .who { font-size: 11px; color: var(--accent-2); font-weight: 700; margin-bottom: 3px; }
.chat-input { display: flex; gap: 10px; margin-top: 12px; }
.chat-input input { flex: 1; }
.quick-q { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 10px; }
.quick-q button { font-size: 12.5px; padding: 6px 12px; border-radius: 999px; border: 1px solid var(--border); background: var(--card); cursor: pointer; color: var(--text); transition: .18s; }
.quick-q button:hover { background: var(--grad-soft); color: var(--primary); }

/* ---------- 讨论区 ---------- */
.thread { border: 1px solid var(--border); border-radius: var(--radius); padding: 16px; margin-bottom: 14px; background: var(--card); }
.thread .head { display: flex; align-items: center; gap: 10px; }
.avatar { width: 34px; height: 34px; border-radius: 50%; display: grid; place-items: center; font-weight: 700; color: #fff; font-size: 14px; }
.avatar.student { background: linear-gradient(135deg,#2563eb,#06b6d4); }
.avatar.teacher { background: linear-gradient(135deg,#f59e0b,#f97316); }
.avatar.ai { background: linear-gradient(135deg,#8b5cf6,#6366f1); }
.role-pill { font-size: 11px; padding: 2px 9px; border-radius: 999px; }
.role-pill.student { background: rgba(37,99,235,.14); color: var(--primary); }
.role-pill.teacher { background: rgba(245,158,11,.16); color: #b45309; }
.role-pill.ai { background: rgba(139,92,246,.16); color: #7c3aed; }
.thread .body { margin: 10px 0; font-size: 14.5px; }
.reply { margin: 10px 0 0 44px; padding: 10px 12px; border-left: 3px solid var(--border); border-radius: 8px; background: rgba(127,127,127,.05); font-size: 13.5px; }
.reply .head { margin-bottom: 4px; }

/* ---------- 学情 KPI ---------- */
.kpi-row { display: grid; grid-template-columns: repeat(auto-fill, minmax(150px,1fr)); gap: 14px; margin-bottom: 18px; }
.kpi { text-align: center; padding: 16px; }
.kpi b { font-size: 26px; color: var(--primary); display: block; }
.kpi span { font-size: 12.5px; color: var(--muted); }
.chart-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.chart-card { padding: 16px; }
.chart-card h3 { margin: 0 0 12px; font-size: 15px; }

/* ---------- 练习 / 批改 ---------- */
.ex-card { margin-bottom: 16px; }
.score-badge { display: inline-grid; place-items: center; width: 64px; height: 64px; border-radius: 50%; background: var(--grad-hero); color: #fff; font-weight: 800; font-size: 18px; box-shadow: 0 8px 20px rgba(37,99,235,.3); }
.score-badge.low { background: linear-gradient(135deg,#ef4444,#f97316); }
.score-badge.mid { background: linear-gradient(135deg,#f59e0b,#fbbf24); }
.diag { border-left: 3px solid var(--primary); padding: 8px 12px; margin: 8px 0; background: rgba(37,99,235,.06); border-radius: 8px; font-size: 13.5px; }
.diag .ok { color: #059669; font-weight: 700; }
.diag .warn { color: #b45309; font-weight: 700; }

/* ---------- 教师后台 ---------- */
.tabs { display: flex; gap: 8px; margin-bottom: 16px; flex-wrap: wrap; }
.tabs button { padding: 8px 16px; border-radius: 999px; border: 1px solid var(--border); background: var(--card); cursor: pointer; color: var(--text); font-size: 13.5px; transition: .18s; }
.tabs button.active { background: var(--grad-hero); color: #fff; border-color: transparent; }
table.tbl { width: 100%; border-collapse: collapse; font-size: 13.5px; }
table.tbl th, table.tbl td { padding: 10px 12px; border-bottom: 1px solid var(--border); text-align: left; }
table.tbl th { color: var(--muted); font-weight: 600; }
table.tbl tr:hover { background: rgba(127,127,127,.05); }
.mini-avatar { width: 26px; height: 26px; border-radius: 50%; display: inline-grid; place-items: center; color: #fff; font-size: 12px; font-weight: 700; }

/* ---------- 学习中心进度环 ---------- */
.progress-ring { --p: 0; width: 96px; height: 96px; border-radius: 50%; display: grid; place-items: center; background:
  conic-gradient(var(--primary) calc(var(--p)*1%), rgba(127,127,127,.18) 0); position: relative; }
.progress-ring::before { content: ""; position: absolute; inset: 8px; border-radius: 50%; background: var(--card-solid); }
.progress-ring b { position: relative; font-size: 20px; color: var(--primary); }

/* ---------- 公告 ---------- */
.announce { border-left: 4px solid var(--accent); padding: 12px 14px; margin-bottom: 12px; background: rgba(245,158,11,.08); border-radius: 8px; }
.announce .t { font-weight: 700; }
.announce .by { font-size: 12px; color: var(--muted); }

/* —— 首页公告条 / 通知 —— */
.ann-strip { display: flex; align-items: center; gap: 10px; padding: 12px 16px; margin-bottom: 16px; border-left: 4px solid var(--accent); }
.ann-strip .ann-dot { width: 10px; height: 10px; border-radius: 50%; background: var(--accent); flex: none; box-shadow: 0 0 0 4px rgba(245,158,11,.18); }
.teacher-note { background: var(--grad-soft); border-radius: 8px; padding: 8px 10px; border: 1px solid var(--border); }

/* —— 我的作业卡片 —— */
.hw-card { border-left: 4px solid var(--muted); transition: transform .2s ease, box-shadow .2s ease; }
.hw-card.ok { border-left-color: #10b981; }
.hw-card.warn { border-left-color: #f59e0b; }
.hw-card.low { border-left-color: #ef4444; }
.hw-card:hover { transform: translateY(-2px); box-shadow: 0 10px 24px rgba(15,23,42,.10); }
.hw-top { display: flex; align-items: center; justify-content: space-between; gap: 10px; margin-bottom: 4px; }
.hw-state { font-size: 12px; font-weight: 700; padding: 3px 10px; border-radius: 999px; color: #fff; }
.hw-state.ok { background: #10b981; }
.hw-state.warn { background: #f59e0b; }
.hw-state.low { background: #ef4444; }

/* ============ 薄弱点本（学生端） ============ */
.weak-card { border-left: 4px solid var(--primary); padding: 18px 20px; margin-bottom: 14px; transition: transform .2s ease, box-shadow .2s ease; }
.weak-card:hover { transform: translateY(-2px); box-shadow: 0 10px 24px rgba(15,23,42,.10); }
.weak-card.low { border-left-color: #ef4444; }
.weak-card.mid { border-left-color: #f59e0b; }
.weak-head { display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.weak-title { display: flex; flex-direction: column; gap: 3px; }
.weak-title b { font-size: 16px; }
.weak-meta { font-size: 12.5px; color: var(--muted); }
.weak-steps { margin-top: 12px; }
.weak-steps .diag:last-child { margin-bottom: 0; }
.freq-list { display: flex; flex-direction: column; gap: 10px; }
.freq-row { display: flex; align-items: center; gap: 12px; }
.freq-label { width: 172px; flex: none; font-size: 13.5px; color: var(--text); }
.empty-state { text-align: center; padding: 44px 20px; }
.empty-emoji { font-size: 42px; }
@media (max-width: 640px) {
  .weak-head { flex-direction: column; align-items: flex-start; }
  .freq-label { width: 120px; }
}

/* ---------- 用户标签 ---------- */
.user-tag { display: inline-flex; align-items: center; gap: 8px; padding: 5px 6px 5px 5px; border-radius: 999px; background: var(--card); border: 1px solid var(--border); font-size: 13px; }
.user-tag .mini-avatar { width: 26px; height: 26px; }
.theme-switch { display: inline-flex; border: 1px solid var(--border); border-radius: 999px; overflow: hidden; }
.theme-switch button { border: none; background: transparent; cursor: pointer; padding: 6px 10px; font-size: 13px; color: var(--muted); }
.theme-switch button.active { background: var(--grad-hero); color: #fff; }

/* ---------- 底部 ---------- */
.footer { text-align: center; color: var(--muted); font-size: 12px; padding: 24px 16px; border-top: 1px solid var(--border); margin-top: 30px; }

/* ---------- 区块 Hero / 统计条（图谱·资源·AI 通用） ---------- */
.section-hero { position: relative; overflow: hidden; border-radius: 20px; padding: 26px 30px; background: var(--grad-hero); color: #fff; box-shadow: 0 16px 44px rgba(37,99,235,.26); display: flex; justify-content: space-between; align-items: flex-end; gap: 16px; flex-wrap: wrap; }
.section-hero h1 { margin: 0 0 8px; font-size: 28px; }
.section-hero .subtitle { margin: 0; opacity: .94; max-width: 680px; font-size: 14.5px; }
.section-hero .legend { display: flex; gap: 8px; flex-wrap: wrap; }
.section-hero .lg { font-size: 12px; padding: 4px 12px; border-radius: 999px; background: rgba(255,255,255,.18); border: 1px solid rgba(255,255,255,.28); }
.section-hero .lg.kw { background: rgba(37,99,235,.28); }
.section-hero .lg.ab { background: rgba(139,92,246,.30); }
.section-hero .lg.rs { background: rgba(245,158,11,.30); }
.section-hero .hero-side { display: flex; flex-direction: column; align-items: flex-end; gap: 10px; }
.graph-toggle { display: inline-flex; background: rgba(255,255,255,.16); border: 1px solid rgba(255,255,255,.3); border-radius: 999px; padding: 3px; gap: 2px; }
.graph-toggle button { border: none; background: transparent; color: #fff; padding: 7px 18px; border-radius: 999px; font-size: 13px; font-weight: 700; cursor: pointer; transition: .18s; }
.graph-toggle button:hover { background: rgba(255,255,255,.28); }
.graph-toggle button.active { background: #fff; color: var(--primary); box-shadow: 0 4px 12px rgba(0,0,0,.16); }

.stat-strip { display: grid; grid-template-columns: repeat(auto-fit, minmax(130px,1fr)); gap: 14px; margin: 16px 0 22px; }
.stat-cell { text-align: center; padding: 16px 10px; }
.stat-cell b { display: block; font-size: 26px; color: var(--primary); }
.stat-cell span { font-size: 12.5px; color: var(--muted); }

/* ---------- 课程图谱 ---------- */
.graph-layout { display: grid; grid-template-columns: 1.4fr 1fr; gap: 16px; align-items: start; }
.graph-panel { padding: 18px; overflow: auto; max-height: 720px; }
.graph-panel pre.mermaid { font-size: 13px; line-height: 1.5; }
.node-detail { padding: 18px; min-height: 220px; }
.nd-empty { color: var(--muted); font-size: 14px; padding: 40px 10px; text-align: center; }
.nd-head { display: flex; flex-direction: column; gap: 4px; }
.nd-reslist { display: flex; flex-direction: column; gap: 8px; }
.nd-res { text-align: left; border: 1px solid var(--border); background: var(--card); border-radius: 12px; padding: 10px 12px; cursor: pointer; color: var(--text); font-size: 13.5px; transition: .18s; display: flex; align-items: center; gap: 8px; }
.nd-res:hover { background: var(--grad-soft); transform: translateX(3px); }
.node-card { cursor: pointer; transition: transform .18s, box-shadow .18s; }
.node-card:hover { transform: translateY(-3px); box-shadow: 0 14px 34px rgba(15,23,42,.14); }
.node-link-count { margin-top: 8px; font-size: 12.5px; color: var(--primary); font-weight: 600; }

/* ---------- 能力图谱 · 竖向可读布局（能力域 / 能力单元联动） ---------- */
.graph-main { display: grid; grid-template-columns: 340px 1fr; gap: 16px; align-items: start; }
.col { border-radius: var(--radius); padding: 16px; min-width: 0; }
.col-domains { background: linear-gradient(180deg, rgba(99,102,241,.14), rgba(99,102,241,.03)); border: 1px solid rgba(99,102,241,.30); }
.col-units { background: linear-gradient(180deg, rgba(6,182,212,.10), rgba(6,182,212,.02)); border: 1px solid rgba(6,182,212,.26); }
.col-head { font-size: 16px; font-weight: 800; margin-bottom: 12px; display: flex; flex-direction: column; gap: 2px; }
.col-head small { font-size: 12px; font-weight: 500; color: var(--muted); }

/* 能力域卡 */
.gcard { background: var(--card-solid); border: 1px solid var(--border); border-radius: var(--radius-sm); padding: 12px 14px; margin-bottom: 12px; cursor: default; transition: transform .2s, box-shadow .2s, border-color .2s; }
.gcard.gc-unit { cursor: pointer; }
.gcard:hover { box-shadow: var(--shadow); }
.gcard.selected { border-color: #f59e0b; box-shadow: 0 0 0 3px rgba(245,158,11,.25), var(--shadow); }
.gcard .gc-title { font-weight: 700; font-size: 15px; margin: 2px 0 4px; color: var(--text); }
.gcard .gc-desc { font-size: 12.5px; color: var(--muted); line-height: 1.55; }
.gc-domain { border-left: 4px solid #6366f1; }
.gc-unit { border-left: 4px solid #06b6d4; position: relative; }
.gc-units { margin-top: 10px; }
.gc-units-label { display: block; font-size: 11.5px; font-weight: 700; color: var(--primary); margin-bottom: 6px; }
.unit-chips { display: flex; flex-wrap: wrap; gap: 6px; }
.uchip { border: 1px solid rgba(99,102,241,.35); background: rgba(99,102,241,.08); color: var(--primary); border-radius: 999px; padding: 4px 10px; font-size: 12px; cursor: pointer; transition: .18s; }
.uchip:hover { background: #6366f1; color: #fff; transform: translateY(-1px); }

/* 能力单元栅格（左右对齐铺排，分组标题跨两列） */
.units-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px; align-items: stretch; }
.ug-span { grid-column: 1 / -1; }
.unit-group-head { font-size: 16px; font-weight: 800; color: var(--primary); margin: 18px 0 10px; padding-left: 10px; border-left: 3px solid var(--accent); }
.gc-unit .gc-count { margin-top: 10px; display: inline-block; border: 1px solid var(--primary); background: var(--grad-soft); color: var(--primary); border-radius: 999px; padding: 4px 12px; font-size: 12px; font-weight: 600; cursor: pointer; transition: .18s; }
.gc-unit .gc-count:hover { background: var(--primary); color: #fff; }
.gc-count.muted { border: none; background: transparent; color: var(--muted); cursor: default; padding-left: 0; }

/* 闪烁联动 */
@keyframes gflash {
  0%, 100% { box-shadow: 0 0 0 3px rgba(245,158,11,.30), var(--shadow); transform: scale(1); }
  20%, 60% { box-shadow: 0 0 0 7px rgba(245,158,11,.75), 0 0 26px rgba(245,158,11,.85); transform: scale(1.04); }
  40%, 80% { box-shadow: 0 0 0 4px rgba(245,158,11,.45), 0 0 14px rgba(245,158,11,.5); transform: scale(1.01); }
}
.gc-unit.flash { animation: gflash .6s ease-in-out 3; border-color: #f59e0b; z-index: 5; }

/* 悬浮资源窗 */
.res-pop { position: absolute; top: 0; left: calc(100% + 12px); width: 300px; z-index: 80; background: var(--card-solid); border: 1px solid var(--accent); border-radius: 14px; box-shadow: 0 18px 44px rgba(15,23,42,.28); padding: 12px; }
.rp-head { display: flex; justify-content: space-between; align-items: center; font-weight: 700; font-size: 13.5px; margin-bottom: 8px; }
.rp-close { border: none; background: transparent; cursor: pointer; font-size: 14px; color: var(--muted); line-height: 1; }
.rp-list { display: flex; flex-direction: column; gap: 7px; max-height: 320px; overflow: auto; }
.rp-res { text-align: left; border: 1px solid var(--border); background: var(--card); border-radius: 10px; padding: 8px 10px; cursor: pointer; font-size: 13px; color: var(--text); display: flex; align-items: center; gap: 7px; transition: .18s; }
.rp-res:hover { background: var(--grad-soft); transform: translateX(3px); }
.rp-empty { font-size: 12.5px; color: var(--muted); }
.tag { font-size: 11px; padding: 2px 8px; border-radius: 999px; background: var(--grad-soft); color: var(--primary); font-weight: 600; white-space: nowrap; }
/* ---------- 资源中心分组 ---------- */
.res-group { margin-bottom: 14px; border: 1px solid var(--border); border-radius: 14px; overflow: hidden; background: var(--card); }
.res-group-head { display: flex; align-items: center; gap: 8px; font-size: 15.5px; font-weight: 700; margin: 0; padding: 12px 14px; background: var(--card); }
.res-group-head.toggle { cursor: pointer; user-select: none; transition: background .18s; }
.res-group-head.toggle:hover { background: var(--grad-soft); }
.rg-dot { width: 8px; height: 8px; border-radius: 50%; background: var(--grad-hero); display: inline-block; flex: none; }
.rg-chevron { display: inline-flex; width: 16px; justify-content: center; color: var(--primary); font-size: 13px; flex: none; }
.rg-count { margin-left: auto; font-size: 12.5px; font-weight: 600; color: var(--muted); background: rgba(15, 23, 42, .06); border-radius: 999px; padding: 2px 10px; }
.res-group-body { padding: 14px; }

/* ---------- AI 学伴 Hub ---------- */
.ai-hub { display: grid; grid-template-columns: 300px 1fr; gap: 16px; align-items: start; }
.ai-side { display: flex; flex-direction: column; gap: 16px; }
.cap-card { display: flex; gap: 12px; align-items: flex-start; padding: 10px 0; border-bottom: 1px dashed var(--border); }
.cap-card:last-child { border-bottom: none; }
.cap-ico { font-size: 19px; width: 38px; height: 38px; border-radius: 10px; display: grid; place-items: center; background: var(--grad-soft); flex: none; }
.ai-main { display: flex; flex-direction: column; }
.ai-main .chat-box { height: 520px; }

/* ---------- 响应式补强 ---------- */
@media (max-width: 900px) {
  .graph-layout, .ai-hub, .graph-main { grid-template-columns: 1fr; }
  .units-grid { grid-template-columns: 1fr; }
  .section-hero { flex-direction: column; align-items: flex-start; }
  .hero { grid-template-columns: 1fr; gap: 22px; }
  .ai-main .chat-box { height: 440px; }
}

/* ---------- 能力总览图（竖向树状 SVG，自适应、无需缩放可读） ---------- */
.ov-block { margin: 18px 0 4px; }
.ov-title { font-size: 17px; font-weight: 800; margin-bottom: 10px; display: flex; flex-direction: column; gap: 3px; color: var(--text); }
.ov-title small { font-size: 12.5px; font-weight: 500; color: var(--muted); }
.ov-wrap { overflow-x: auto; padding: 6px 2px 10px; border: 1px solid var(--border); border-radius: var(--radius); background: var(--card); }
.ov-svg { width: 100%; height: auto; min-width: 820px; display: block; }
.ov-link { fill: none; stroke: rgba(99,102,241,.42); stroke-width: 2; }
.ov-panel-dom { fill: rgba(99,102,241,.06); stroke: rgba(99,102,241,.26); stroke-width: 1.5; }
.ov-panel-ext { fill: rgba(6,182,212,.07); stroke: rgba(6,182,212,.34); stroke-width: 1.5; }
.ov-node { cursor: pointer; }
.ov-node rect { transition: filter .18s, stroke .18s; }
.ov-node:hover rect { filter: brightness(1.06); }
.ov-root rect { fill: url(#ovGrad); }
.ov-root text { fill: #fff; font-weight: 800; font-size: 19px; }
.ov-domain rect { fill: #6366f1; }
.ov-domain text { fill: #fff; font-weight: 700; font-size: 14.5px; }
.ov-unit rect { fill: #ecfeff; stroke: #06b6d4; stroke-width: 1.5; }
.ov-unit text { fill: #0e5e6b; font-weight: 600; font-size: 13px; }
.ov-node text { text-anchor: middle; dominant-baseline: central; font-family: inherit; pointer-events: none; }

/* ============ 知识图谱专属主题（绿/青配色，与能力图谱靛/紫明确区分） ============ */
#view-graph.kg-mode { --kg-accent: #059669; --kg-accent2: #0d9488; --kg-soft: rgba(5,150,105,.12); --kg-border: rgba(5,150,105,.30); }
#view-graph.kg-mode .section-hero { background: linear-gradient(135deg, #059669 0%, #0d9488 100%); box-shadow: 0 16px 44px rgba(5,150,105,.26); }
#view-graph.kg-mode .graph-toggle { background: rgba(255,255,255,.18); border-color: rgba(255,255,255,.34); }
#view-graph.kg-mode .graph-toggle button.active { color: #059669; }
#view-graph.kg-mode .legend .lg.ab { background: rgba(5,150,105,.36); }
#view-graph.kg-mode .legend .lg.kw { background: rgba(13,148,136,.36); }
#view-graph.kg-mode .ov-link { stroke: rgba(5,150,105,.42); }
#view-graph.kg-mode .ov-panel-dom { fill: rgba(5,150,105,.07); stroke: rgba(5,150,105,.28); }
#view-graph.kg-mode .ov-root rect { fill: #047857; }
#view-graph.kg-mode .ov-domain rect { fill: #059669; }
#view-graph.kg-mode .ov-unit rect { fill: #ecfdf5; stroke: #0d9488; }
#view-graph.kg-mode .ov-unit text { fill: #065f46; }
#view-graph.kg-mode .gcard.gc-domain { border-left-color: #059669; }
#view-graph.kg-mode .gc-units-label { color: #059669; }
#view-graph.kg-mode .gcard.gc-unit { border-left-color: #0d9488; }
#view-graph.kg-mode .gcard.selected { border-color: #0d9488; box-shadow: 0 0 0 3px rgba(13,148,136,.25), var(--shadow); }
#view-graph.kg-mode .gc-unit .gc-count { border-color: #059669; color: #059669; background: var(--kg-soft); }
#view-graph.kg-mode .gc-unit .gc-count:hover { background: #059669; color: #fff; }
#view-graph.kg-mode .uchip { border-color: rgba(5,150,105,.4); background: var(--kg-soft); color: #047857; }
#view-graph.kg-mode .uchip:hover { background: #059669; color: #fff; transform: translateY(-1px); }

/* ============ 浮动 AI 学伴（随时答疑，不离开当前页面） ============ */
.ai-fab {
  position: fixed; right: 22px; bottom: 22px; z-index: 1200;
  display: flex; align-items: center; gap: 8px;
  padding: 12px 18px; border-radius: 999px; border: none; cursor: pointer;
  background: var(--grad-hero); color: #fff; font-weight: 700; font-size: 14px;
  box-shadow: 0 10px 30px rgba(37,99,235,.35); transition: transform .2s, box-shadow .2s;
}
.ai-fab:hover { transform: translateY(-2px); box-shadow: 0 14px 40px rgba(37,99,235,.46); }
.ai-fab .pulse { width: 9px; height: 9px; border-radius: 50%; background: #fff; animation: fabPulse 1.8s infinite; }
@keyframes fabPulse { 0%,100% { opacity: .4; } 50% { opacity: 1; } }
.ai-companion {
  position: fixed; right: 18px; bottom: 18px; width: 384px; max-width: calc(100vw - 36px);
  height: 580px; max-height: calc(100vh - 36px); z-index: 1300;
  background: var(--card); border: 1px solid var(--border); border-radius: 18px;
  box-shadow: 0 24px 60px rgba(15,23,42,.30); display: none; flex-direction: column; overflow: hidden;
}
.ai-companion.open { display: flex; animation: compIn .22s ease; }
@keyframes compIn { from { opacity: 0; transform: translateY(12px) scale(.98); } to { opacity: 1; transform: none; } }
.ai-companion .comp-head { display: flex; align-items: center; gap: 8px; padding: 14px 16px; background: var(--grad-hero); color: #fff; }
.ai-companion .comp-head .who { font-weight: 700; }
.ai-companion .comp-head .close { margin-left: auto; background: rgba(255,255,255,.22); border: none; color: #fff; width: 28px; height: 28px; border-radius: 8px; cursor: pointer; font-size: 16px; line-height: 1; }
.ai-companion .comp-head .close:hover { background: rgba(255,255,255,.38); }
.ai-companion .comp-chat { flex: 1; overflow-y: auto; padding: 14px 12px; display: flex; flex-direction: column; gap: 12px; }
.ai-companion .comp-foot { padding: 10px 12px; border-top: 1px solid var(--border); }
.ai-companion .comp-quick { display: flex; gap: 6px; flex-wrap: wrap; margin-bottom: 8px; }
.ai-companion .comp-quick button { font-size: 11.5px; padding: 5px 10px; border-radius: 999px; border: 1px solid var(--border); background: var(--card); color: var(--text); cursor: pointer; }
.ai-companion .comp-quick button:hover { background: var(--grad-soft); color: var(--primary); }
.ai-companion .comp-input { display: flex; gap: 10px; }
.ai-companion .comp-input input { flex: 1; }

/* ============ 知识图谱横向布局（项目横向带 + 知识点横向带） ============ */
.kg-section { margin: 20px 0 4px; }
.kg-sec-head { font-size: 17px; font-weight: 800; margin-bottom: 12px; display: flex; flex-direction: column; gap: 3px; color: var(--text); }
.kg-sec-head small { font-size: 12.5px; font-weight: 500; color: var(--muted); }
.kg-projects { display: flex; gap: 14px; overflow-x: auto; padding: 4px 2px 14px; }
.kg-proj { flex: 0 0 auto; width: 272px; background: var(--card-solid); border: 1px solid var(--kg-border); border-top: 3px solid var(--kg-accent); border-radius: var(--radius-sm); padding: 14px 16px; transition: transform .2s, box-shadow .2s; }
.kg-proj:hover { box-shadow: var(--shadow); transform: translateY(-2px); }
.kg-proj-head { font-weight: 800; font-size: 15px; display: flex; align-items: center; gap: 8px; flex-wrap: wrap; color: var(--text); }
.kg-hours { font-size: 11px; font-weight: 700; color: #fff; background: var(--kg-accent); border-radius: 999px; padding: 2px 9px; white-space: nowrap; }
.kg-proj-desc { font-size: 12.5px; color: var(--muted); line-height: 1.55; margin: 8px 0 10px; }
.kg-proj-chips { display: flex; flex-wrap: wrap; gap: 6px; }
.kg-proj-chips.kg-empty { font-size: 12px; color: var(--muted); }
.kg-points { display: grid; grid-template-columns: repeat(auto-fill, minmax(248px, 1fr)); gap: 12px; align-items: start; }
.kg-proj-tag { display: inline-block; font-size: 11px; font-weight: 700; color: #047857; background: var(--kg-soft); border-radius: 999px; padding: 2px 9px; margin-bottom: 7px; }

/* 知识图谱横向布局响应式：窄屏项目带改为自动换行 */
@media (max-width: 720px) {
  .kg-projects { flex-wrap: wrap; }
  .kg-proj { width: 100%; flex: 1 1 240px; }
}

/* ---------- 资源卡顶部 + 慕课一键跳转 ---------- */
.res-card-top { display: flex; align-items: center; gap: 6px; flex-wrap: wrap; }
.mooc-chip { margin-left: auto; border: 1px solid var(--primary); background: var(--grad-soft); color: var(--primary); border-radius: 999px; padding: 2px 10px; font-size: 12px; cursor: pointer; transition: .18s; white-space: nowrap; }
.mooc-chip:hover { background: var(--primary); color: #fff; }
.mooc-jump { display: inline-flex; align-items: center; gap: 8px; background: var(--grad-hero); color: #fff; padding: 11px 20px; border-radius: 999px; text-decoration: none; font-weight: 600; font-size: 14px; box-shadow: 0 8px 20px rgba(37,99,235,.32); transition: transform .18s cubic-bezier(.16,1,.3,1), box-shadow .18s; }
.mooc-jump:hover { transform: translateY(-2px) scale(1.02); box-shadow: 0 12px 26px rgba(37,99,235,.42); }

/* ---------- 响应式 ---------- */
@media (max-width: 900px) { .chart-row { grid-template-columns: 1fr; } }
@media (max-width: 720px) {
  .topbar { flex-wrap: wrap; }
  .nav { width: 100%; order: 3; border-top: 1px solid var(--border); padding-top: 8px; }
  .auth { margin-left: 0; }
  .hero h1 { font-size: 26px; }
  .container { padding: 0 14px 50px; }
  .kpi-row { grid-template-columns: repeat(2, 1fr); }
}

/* ---------- 登录落地页 / 欢迎画面 ---------- */
.overlay-screen { position: fixed; inset: 0; z-index: 80; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 26px; padding: 28px; background: radial-gradient(1200px 600px at 50% -10%, rgba(99,102,241,.18), transparent), var(--bg, #f3f4f8); animation: fade .25s; }
.overlay-screen[hidden] { display: none; }
.login-hero { text-align: center; }
.login-brand { font-size: 24px; font-weight: 800; letter-spacing: .3px; }
.login-brand .dot { margin: 0 4px; color: var(--primary); }
.login-sub { color: var(--muted); margin: 10px 0 0; font-size: 14px; }
.portal-wrap { display: grid; grid-template-columns: repeat(3, minmax(220px, 1fr)); gap: 18px; width: min(960px, 94vw); }
.portal-card { text-align: left; background: var(--card); border: 1px solid var(--border); border-radius: 20px; padding: 22px 20px; cursor: pointer; transition: transform .22s cubic-bezier(.16,1,.3,1), box-shadow .22s, border-color .22s; display: flex; flex-direction: column; gap: 10px; box-shadow: var(--shadow); }
.portal-card:hover { transform: translateY(-4px); box-shadow: 0 18px 40px rgba(37,99,235,.22); border-color: var(--primary); }
.portal-card.student { border-top: 4px solid #6366f1; }
.portal-card.teacher { border-top: 4px solid #0ea5e9; }
.portal-card.guest { border-top: 4px solid #f59e0b; }
.portal-icon { font-size: 30px; }
.portal-name { font-size: 17px; }
.portal-desc { color: var(--muted); font-size: 13px; margin: 0; line-height: 1.5; }
.portal-demo { font-size: 12.5px; background: var(--grad-soft, #eef2ff); border-radius: 12px; padding: 8px 10px; color: var(--text); }
.portal-enter { margin-top: auto; color: var(--primary); font-weight: 700; font-size: 14px; }
.login-other { background: transparent; border: 1px solid var(--border); color: var(--muted); border-radius: 999px; padding: 9px 18px; cursor: pointer; font-size: 13px; transition: .18s; }
.login-other:hover { color: var(--text); border-color: var(--primary); }

/* 欢迎画面 */
.overlay-screen.welcome { z-index: 90; background: radial-gradient(900px 500px at 50% 30%, rgba(99,102,241,.22), transparent), var(--bg, #f3f4f8); }
.welcome-inner { text-align: center; display: flex; flex-direction: column; align-items: center; gap: 14px; }
.welcome-inner h1 { margin: 0; font-size: 30px; }
.welcome-name { color: var(--primary); }
.welcome-role { color: var(--muted); margin: 0; font-size: 15px; }
.welcome-spinner { width: 46px; height: 46px; border-radius: 50%; border: 4px solid var(--grad-soft, #e0e7ff); border-top-color: var(--primary); animation: spin 1s linear infinite; }
.welcome.show .welcome-inner { animation: pop .5s cubic-bezier(.16,1,.3,1); }
@keyframes spin { to { transform: rotate(360deg); } }
@keyframes pop { from { opacity: 0; transform: translateY(14px) scale(.96); } to { opacity: 1; transform: none; } }
@keyframes fade { from { opacity: 0; } to { opacity: 1; } }

/* 学生首页可点击卡 */
.home-cards .home-card.clickable { cursor: pointer; transition: transform .2s cubic-bezier(.16,1,.3,1), box-shadow .2s, border-color .2s; }
.home-cards .home-card.clickable:hover { transform: translateY(-3px); box-shadow: 0 14px 32px rgba(37,99,235,.18); border-color: var(--primary); }
.grid.cols-4 { grid-template-columns: repeat(4, 1fr); }

/* 教师资源管理：按模块折叠 */
.tres-group { border: 1px solid var(--border); border-radius: 16px; margin-bottom: 12px; overflow: hidden; background: var(--card); }
.tres-head { display: flex; align-items: center; gap: 10px; padding: 14px 16px; cursor: pointer; font-weight: 600; transition: background .18s; }
.tres-head:hover { background: var(--grad-soft, #eef2ff); }
.tres-head .rg-chevron { color: var(--primary); font-weight: 700; }
.tres-head .rg-dot { width: 9px; height: 9px; border-radius: 50%; background: var(--primary); }
.tres-head .rg-count { margin-left: auto; color: var(--muted); font-weight: 400; font-size: 13px; }
.tres-body { padding: 4px 16px 16px; }

/* 教师 AI 智能体 */
.agent-grid { margin-top: 6px; }
.agent-card { display: flex; flex-direction: column; gap: 14px; }
.agent-head { display: flex; gap: 14px; align-items: flex-start; }
.agent-icon { font-size: 30px; }
.agent-status { font-size: 13px; color: var(--muted); }
.agent-slot { min-height: 120px; border: 1.5px dashed var(--border); border-radius: 14px; display: flex; align-items: center; justify-content: center; color: var(--muted); font-size: 13px; background: repeating-linear-gradient(45deg, transparent, transparent 10px, rgba(127,127,127,.04) 10px, rgba(127,127,127,.04) 20px); }

/* —— AI 备课智能体生成面板 —— */
.beike-panel { display: flex; flex-direction: column; gap: 12px; }
.beike-row { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.beike-label { font-size: 13px; font-weight: 600; color: var(--primary); min-width: 56px; }
.beike-input { flex: 1; min-width: 160px; padding: 8px 12px; border-radius: 10px; border: 1.5px solid var(--border); background: var(--bg-soft); color: var(--text); font-size: 14px; outline: none; transition: border-color .2s; }
.beike-input:focus { border-color: var(--primary); }
.beike-chk { font-size: 14px; display: inline-flex; align-items: center; gap: 6px; cursor: pointer; }
.beike-out { margin-top: 2px; }
.beike-cards { display: flex; flex-direction: column; gap: 10px; }
.beike-card { padding: 12px 14px; border-radius: 12px; background: var(--grad-soft); border: 1px solid rgba(139,92,246,.18); animation: pop .28s cubic-bezier(.16,1,.3,1); }
@keyframes pop { from { opacity: 0; transform: translateY(8px) scale(.98); } to { opacity: 1; transform: none; } }

/* —— 轻量提示条 —— */
.toast { position: fixed; left: 50%; bottom: 32px; transform: translateX(-50%) translateY(20px); background: rgba(15,23,42,.92); color: #fff; padding: 10px 18px; border-radius: 999px; font-size: 14px; box-shadow: 0 10px 30px rgba(0,0,0,.25); opacity: 0; pointer-events: none; transition: all .3s cubic-bezier(.16,1,.3,1); z-index: 2000; }
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

@media (max-width: 720px) {
  .portal-wrap { grid-template-columns: 1fr; }
  .grid.cols-4 { grid-template-columns: 1fr 1fr; }
}

/* ============ 教师批改台 · 按作业聚合（B） ============ */
.hidden { display: none !important; }

/* 中间层级标题（主从区分，E 视觉统一） */
.sub-sec { font-size: 16px; font-weight: 800; color: var(--text); margin: 22px 0 12px; display: flex; align-items: center; gap: 9px; letter-spacing: .2px; }
.sub-sec::before { content: ""; width: 4px; height: 16px; border-radius: 3px; background: var(--accent); display: inline-block; }

/* 作业组卡（premium hover 与 weak-card/hw-card 一致） */
.asg-group { padding: 0; overflow: hidden; transition: transform .2s ease, box-shadow .2s ease; }
.asg-group:hover { transform: translateY(-2px); box-shadow: 0 12px 28px rgba(15,23,42,.12); }
.asg-head { display: flex; align-items: center; justify-content: space-between; gap: 16px; flex-wrap: wrap; padding: 16px 20px; cursor: pointer; transition: background .18s; }
.asg-head:hover { background: var(--grad-soft, #eef2ff); }
.asg-title { display: flex; align-items: center; gap: 8px; font-size: 15px; }
.asg-title b { color: var(--text); }
.asg-stat { display: flex; flex-wrap: wrap; gap: 8px; }
.asg-meta { padding: 0 20px 12px; font-size: 12.5px; color: var(--muted); }
.asg-rows { padding: 0 8px 8px; }
.asg-rows table.tbl th, .asg-rows table.tbl td { padding: 9px 12px; }

/* 状态药丸（与 hw-state / score-badge 同配色语言：ok绿 / warn橙 / low红 / review蓝） */
.stat-pill { font-size: 12px; font-weight: 700; padding: 3px 11px; border-radius: 999px; color: #fff; white-space: nowrap; }
.stat-pill.ok { background: #10b981; }
.stat-pill.warn { background: #f59e0b; }
.stat-pill.low { background: #ef4444; }
.stat-pill.review { background: var(--primary); }

/* 未提交行淡化（主从区分） */
.row-muted td { color: var(--muted); }
.row-muted:hover { background: transparent !important; }

/* E 视觉收口：统一卡片列表间距节奏 */
.sec-title + .glass, .sub-sec + .glass { margin-top: 4px; }
.kpi-row .kpi { border: 1px solid var(--border); }

/* ---------- 微课 / 动画 / 仿真 资源卡封面（原创+AI 以图代言，提升点击率与原创率指标） ---------- */
.res-card.has-cover { padding: 0; overflow: hidden; }
.res-cover { position: relative; width: 100%; aspect-ratio: 16 / 9; overflow: hidden; background: var(--grad-soft); }
.res-cover img { width: 100%; height: 100%; object-fit: cover; display: block; transition: transform .4s cubic-bezier(.16,1,.3,1); }
.res-card.has-cover:hover .res-cover img { transform: scale(1.06); }
.res-cover-mark { position: absolute; top: 10px; left: 10px; font-size: 11px; font-weight: 700; color: #fff; background: linear-gradient(135deg,#8b5cf6,#6d28d9); padding: 3px 10px; border-radius: 999px; box-shadow: 0 4px 12px rgba(139,92,246,.42); letter-spacing: .3px; }
.res-card.has-cover .res-card-top,
.res-card.has-cover h4,
.res-card.has-cover p { padding-left: 16px; padding-right: 16px; }
.res-card.has-cover .res-card-top { padding-top: 14px; }
.res-card.has-cover h4 { margin-top: 2px; }
.res-card.has-cover p { padding-bottom: 16px; }

/* 动画/仿真 卡片占位封面（无位图 → 渐变 + 类型标识，保证 premium 观感且不破图） */
.res-cover-ph {
  position: relative; width: 100%; aspect-ratio: 16 / 9; overflow: hidden;
  display: grid; place-items: center; transition: transform .4s cubic-bezier(.16,1,.3,1);
}
.res-cover-ph.anim { background: linear-gradient(135deg, #14b8a6 0%, #0ea5e9 100%); }
.res-cover-ph.sim  { background: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%); }
.res-cover-ph .ph-ico { font-size: 52px; color: #fff; opacity: .92; filter: drop-shadow(0 6px 16px rgba(0,0,0,.25)); }
.res-cover-ph .ph-label {
  position: absolute; bottom: 10px; right: 12px; font-size: 12px; font-weight: 700;
  color: #fff; background: rgba(0,0,0,.22); padding: 3px 10px; border-radius: 999px; backdrop-filter: blur(6px);
}
.res-card.has-cover:hover .res-cover-ph { transform: scale(1.04); }

/* 微课图文容器 */
.micro-wrap { margin-top: 6px; }

/* 动画内联 SVG 自适应铺满（深色衬底，premium 观感） */
.anim-svg { width: 100%; height: auto; display: block; border-radius: 16px; margin: 0; border: 1px solid var(--border); background: transparent; box-shadow: var(--shadow); }
.anim-stage { margin: 4px 0 16px; line-height: 0; }

/* ---------- 三维动画：镀锌钢管螺纹连接（步骤覆盖层，文字与 3D 分离不重叠） ---------- */
.thread-stage { line-height: 1.7; margin: 2px 0 12px; }
.thread-head { display: flex; flex-direction: column; gap: 10px; margin-bottom: 10px; }
.thread-title { font-size: 16.5px; font-weight: 700; color: var(--text); }
.thread-steps { display: flex; gap: 8px; flex-wrap: wrap; }
.thread-step {
  display: inline-flex; align-items: center; padding: 7px 14px; border-radius: 999px; cursor: pointer;
  border: 1px solid var(--border); background: rgba(255, 255, 255, .05); color: var(--muted); font-size: 13.5px; transition: .2s;
}
.thread-step .num {
  display: inline-flex; align-items: center; justify-content: center; width: 20px; height: 20px; border-radius: 50%;
  background: rgba(120, 160, 255, .18); color: var(--text); margin-right: 8px; font-size: 12px; font-weight: 700;
}
.thread-step:hover { border-color: rgba(120, 170, 255, .6); transform: translateY(-1px); }
.thread-step.active { border-color: var(--accent); background: var(--grad-soft); color: var(--text); font-weight: 700; box-shadow: 0 4px 14px rgba(79, 124, 255, .22); }
.thread-step.active .num { background: var(--accent); color: #1a1205; }
.thread-step.done .num { background: rgba(16, 185, 129, .25); color: #10b981; }
.thread-step.done.active .num { background: #10b981; color: #04231a; }
.thread-canvas {
  width: 100%; height: 460px; border-radius: 16px; overflow: hidden; position: relative;
  background: radial-gradient(800px 420px at 70% -10%, rgba(91, 140, 255, .22), transparent 60%), linear-gradient(180deg, #0b1220 0%, #0f1b33 100%);
  border: 1px solid var(--border); box-shadow: inset 0 0 60px rgba(0, 0, 0, .45), var(--shadow);
}
.thread-canvas canvas { display: block; }
.thread-foot { display: flex; align-items: center; gap: 12px; margin-top: 12px; }
.thread-desc {
  flex: 1; min-height: 22px; font-size: 14px; line-height: 1.7; color: var(--text);
  padding: 10px 14px; border-radius: 12px; background: var(--grad-soft); border: 1px solid var(--border);
}
.thread-replay {
  flex: none; padding: 9px 16px; border-radius: 10px; border: none; cursor: pointer; font-size: 13.5px; font-weight: 600;
  background: linear-gradient(135deg, #4f7cff, #6f9bff); color: #fff; transition: .2s;
}
.thread-replay:hover { transform: translateY(-1px); box-shadow: 0 6px 18px rgba(79, 124, 255, .35); }
.thread-progress { height: 6px; border-radius: 999px; background: var(--border); margin-top: 12px; overflow: hidden; }
.thread-progress i { display: block; height: 100%; width: 0%; border-radius: 999px; background: linear-gradient(90deg, var(--accent), var(--accent-2)); transition: width .12s linear; }

/* 仿真容器（Three.js 挂载点） */
.sim-wrap { margin-top: 4px; }
.sim-intro { color: var(--muted); font-size: 14px; margin: 0 0 12px; line-height: 1.7; }
.sim-mount {
  width: 100%; min-height: 360px; border-radius: 16px; overflow: hidden; position: relative;
  background:
    radial-gradient(800px 400px at 70% -10%, rgba(91,140,255,.20), transparent 60%),
    linear-gradient(180deg, #0b1220 0%, #0f1b33 100%);
  border: 1px solid var(--border);
  box-shadow: inset 0 0 60px rgba(0,0,0,.45), var(--shadow);
}
.sim-mount canvas { display: block; }
.sim-tip {
  margin-top: 12px; padding: 10px 14px; border-radius: 12px; font-size: 13.5px; line-height: 1.6;
  background: var(--grad-soft); border: 1px solid var(--border); color: var(--text); transition: .25s;
}
.sim-tip.ok { background: linear-gradient(135deg, rgba(16,185,129,.18), rgba(6,182,212,.16)); border-color: rgba(16,185,129,.45); color: #047857; font-weight: 600; }
[data-theme="dark"] .sim-tip.ok { color: #6ee7b7; }

/* ---------- 仿真：四步流程（切管→加热→对接→冷却） ---------- */
.sim-steps { display: flex; gap: 8px; flex-wrap: wrap; margin: 10px 0 6px; }
.sim-step {
  padding: 8px 14px; border-radius: 10px; border: 1px solid var(--border, #2a3550);
  background: rgba(255, 255, 255, .04); color: var(--text, #cdd6e6); font-size: 14px; cursor: pointer; transition: .2s;
}
.sim-step:hover { border-color: rgba(120, 170, 255, .6); }
.sim-step.active { border-color: #4f7cff; background: rgba(79, 124, 255, .18); color: #cfe0ff; box-shadow: 0 4px 14px rgba(79, 124, 255, .25); }
.sim-step.done { opacity: .9; }
.sim-step.done.active { border-color: #10b981; background: rgba(16, 185, 129, .16); }
.sim-actions { margin: 8px 0; min-height: 4px; }
.sim-btn {
  padding: 9px 18px; border-radius: 10px; border: none; cursor: pointer; font-size: 14px; font-weight: 600;
  background: linear-gradient(135deg, #4f7cff, #6f9bff); color: #fff; transition: .2s;
}
.sim-btn:hover { transform: translateY(-1px); box-shadow: 0 6px 18px rgba(79, 124, 255, .35); }
.sim-status {
  margin: 8px 0 0; padding: 10px 14px; border-radius: 10px; min-height: 20px; font-size: 14px; line-height: 1.6;
  background: rgba(255, 255, 255, .05); border: 1px solid var(--border, #2a3550); color: var(--text, #cdd6e6);
}
.sim-status.ok { background: rgba(16, 185, 129, .14); border-color: rgba(16, 185, 129, .5); color: #bff3da; }

/* ---------- 微课/动画/视频弹窗（图文脚本 + AI 配图 + 内联 SVG） ---------- */
.modal-box.wide { width: 1040px; max-width: 96vw; max-height: 92vh; overflow-y: auto; overscroll-behavior: contain; }
/* 放大态：接近全屏，便于看清完整截面/动画 */
.modal-box.max { width: min(97vw, 1360px); max-height: 95vh; }
.modal-box.max .anim-svg { max-width: 1180px; margin: 0 auto; }
.res-expand { float: right; margin-left: 8px; }

/* 练习/作业答题弹窗：较宽但不过分，题目与解析阅读舒适 */
.modal-box.quiz { width: 760px; max-width: 94vw; }

/* 提交成功横幅（批改完成后顶部醒目提示，消除「是否提交成功」疑虑） */
.submit-banner { background: linear-gradient(135deg, #10b981, #059669); color: #fff; font-weight: 700; font-size: 14.5px; padding: 12px 16px; border-radius: 14px; margin-bottom: 14px; box-shadow: 0 8px 22px rgba(16,185,129,.32); display: flex; align-items: center; gap: 8px; }

/* 答案解析行：你的答案 / 正确答案 / 解析 三段清晰分行 */
.ans-line { margin: 4px 0 0; line-height: 1.6; }
.ans-line .lbl { color: var(--muted); font-weight: 600; margin-right: 4px; }
.ans-line .mine.wrong { color: #dc2626; font-weight: 600; }
.ans-line .mine.right { color: #16a34a; font-weight: 600; }
.ans-line .correct { color: #16a34a; font-weight: 700; }
.ans-line .blank { color: var(--muted); font-style: italic; }

/* 交互式识图任务（中水系统组成探究 · D） */
.task-wrap { width: 100%; }
.zt-shell { display: flex; flex-direction: column; gap: 14px; }
.zt-tabs { display: flex; gap: 10px; }
.zt-tab {
  flex: none; padding: 9px 18px; border-radius: 12px; cursor: pointer; font-size: 14px; font-weight: 600;
  border: 1px solid var(--border); background: var(--card); color: var(--muted); transition: .2s;
}
.zt-tab:hover { border-color: rgba(120,170,255,.6); transform: translateY(-1px); }
.zt-tab.active { background: var(--grad-hero); color: #fff; border-color: transparent; box-shadow: 0 8px 20px rgba(37,99,235,.28); }
.zt-progress { font-size: 14px; color: var(--muted); display: flex; align-items: baseline; gap: 8px; flex-wrap: wrap; }
.zt-progress b { color: var(--primary); font-size: 18px; font-weight: 800; }
.zt-hint { font-size: 12.5px; color: var(--muted); opacity: .85; }

/* 拖拽流程槽位 */
.zt-flow { display: flex; align-items: stretch; gap: 8px; overflow-x: auto; padding: 6px 2px 12px; }
.zt-slot {
  flex: 1 1 0; min-width: 132px; min-height: 96px; border-radius: 14px; cursor: pointer;
  border: 2px dashed var(--border); background: var(--card); display: flex; flex-direction: column;
  align-items: center; justify-content: center; gap: 6px; text-align: center; transition: .2s; color: var(--muted);
}
.zt-slot:hover { border-color: rgba(120,170,255,.55); transform: translateY(-2px); }
.zt-slot-ico { width: 40px; height: 40px; border-radius: 12px; display: grid; place-items: center; background: var(--grad-soft); font-size: 20px; font-weight: 800; color: var(--text); }
.zt-slot-name { font-size: 13px; font-weight: 600; color: var(--text); line-height: 1.3; }
.zt-slot.done { border-style: solid; border-color: #10b981; background: rgba(16,185,129,.10); color: var(--text); box-shadow: 0 6px 16px rgba(16,185,129,.18); }
.zt-slot.done .zt-slot-ico { background: rgba(16,185,129,.22); }
.zt-slot.zt-bad { border-color: #ef4444; background: rgba(239,68,68,.10); animation: ztShake .42s; }
.zt-slot.zt-warn { border-color: var(--accent); animation: ztShake .42s; }
@keyframes ztShake { 0%,100%{transform:translateX(0)} 20%{transform:translateX(-6px)} 40%{transform:translateX(6px)} 60%{transform:translateX(-4px)} 80%{transform:translateX(4px)} }
.zt-arrow { flex: none; align-self: center; color: var(--accent-2); font-size: 22px; font-weight: 800; }

/* 部件托盘 */
.zt-tray { display: flex; flex-wrap: wrap; gap: 10px; padding: 14px; border-radius: 14px; background: var(--card); border: 1px solid var(--border); }
.zt-card {
  display: inline-flex; align-items: center; gap: 8px; padding: 10px 16px; border-radius: 12px; cursor: grab;
  border: 1px solid var(--border); background: #fff; color: var(--text); font-size: 14px; font-weight: 600;
  box-shadow: var(--shadow); transition: .18s; user-select: none;
}
[data-theme="dark"] .zt-card { background: var(--card-solid); }
.zt-card:hover { transform: translateY(-2px); box-shadow: 0 10px 22px rgba(37,99,235,.20); }
.zt-card:active { cursor: grabbing; }
.zt-card.sel { border-color: var(--primary); background: var(--grad-soft); box-shadow: 0 0 0 3px rgba(37,99,235,.25); }
.zt-card-ico { font-size: 18px; }
.zt-bar { display: flex; align-items: center; gap: 14px; }
.zt-reset { padding: 9px 16px; border-radius: 10px; border: 1px solid var(--border); background: var(--card); color: var(--text); cursor: pointer; font-size: 13.5px; font-weight: 600; transition: .2s; }
.zt-reset:hover { border-color: rgba(120,170,255,.6); transform: translateY(-1px); }
.zt-celebrate { font-size: 14.5px; font-weight: 700; color: #10b981; }

/* 功能连线 */
.zt-link-wrap { position: relative; display: flex; justify-content: space-between; gap: 10px; padding: 8px 4px; }
.zt-col { display: flex; flex-direction: column; gap: 12px; flex: 1 1 0; min-width: 0; }
.zt-lunit, .zt-lfunc {
  display: flex; align-items: center; gap: 10px; padding: 12px 14px; border-radius: 12px; cursor: pointer; text-align: left;
  border: 1px solid var(--border); background: var(--card); color: var(--text); font-size: 14px; font-weight: 600; transition: .2s; line-height: 1.35;
}
.zt-lunit:hover, .zt-lfunc:hover { border-color: rgba(120,170,255,.6); transform: translateX(2px); }
.zt-lunit-ico { font-size: 20px; flex: none; }
.zt-lunit.sel, .zt-lfunc.sel { border-color: var(--primary); box-shadow: 0 0 0 3px rgba(37,99,235,.25); background: var(--grad-soft); }
.zt-lunit.done, .zt-lfunc.done { border-color: #10b981; background: rgba(16,185,129,.12); color: var(--text); cursor: default; }
.zt-link-canvas { position: absolute; left: 0; top: 0; width: 100%; height: 100%; pointer-events: none; }
.zt-link-line { stroke: var(--primary); stroke-width: 3; stroke-linecap: round; opacity: .85; }

/* 详情弹出（点击标注） */
.zt-detail { position: relative; border-radius: 14px; padding: 16px 18px; background: var(--grad-soft); border: 1px solid var(--border); margin-top: 4px; }
.zt-detail h4 { margin: 6px 0 8px; font-size: 16px; color: var(--text); }
.zt-detail-ico { font-size: 26px; }
.zt-detail p { margin: 4px 0; font-size: 13.5px; line-height: 1.7; color: var(--text); }
.zt-detail-x { position: absolute; right: 10px; top: 8px; width: 28px; height: 28px; border-radius: 8px; border: none; background: rgba(15,23,42,.06); color: var(--text); font-size: 18px; cursor: pointer; line-height: 1; }
.zt-detail-x:hover { background: rgba(15,23,42,.12); }
.micro-content { font-size: 14.5px; line-height: 1.82; color: var(--text); }
.micro-hero { width: 100%; display: block; border-radius: 14px; margin: 0 0 14px; border: 1px solid var(--border); box-shadow: var(--shadow); }
.micro-intro p { margin: 0 0 4px; color: var(--muted); font-size: 14px; }
.micro-scene { position: relative; margin: 14px 0; padding: 16px 18px; background: var(--grad-soft); border: 1px solid var(--border); border-left: 4px solid var(--primary); border-radius: 14px; }
.micro-scene h3 { display: inline-flex; align-items: center; gap: 10px; margin: 0 0 8px; font-size: 16px; }
.scene-num { display: inline-grid; place-items: center; min-width: 28px; height: 28px; padding: 0 8px; border-radius: 999px; background: var(--grad-hero); color: #fff; font-weight: 800; font-size: 13px; letter-spacing: .5px; }
.micro-scene p { margin: 8px 0; }
.micro-scene img { width: 100%; display: block; border-radius: 12px; margin: 10px 0; border: 1px solid var(--border); }
.micro-scene ul { margin: 8px 0; padding-left: 20px; }
.micro-scene li { margin: 4px 0; }
mark { background: rgba(37,99,235,.20); color: var(--text); padding: 1px 6px; border-radius: 6px; font-weight: 600; }
.micro-table-wrap { overflow-x: auto; margin: 10px 0; border-radius: 12px; border: 1px solid var(--border); }
.micro-table { width: 100%; border-collapse: collapse; font-size: 13.5px; }
.micro-table th, .micro-table td { padding: 9px 12px; text-align: left; border-bottom: 1px solid var(--border); white-space: nowrap; }
.micro-table thead th { background: var(--grad-soft); font-weight: 700; color: var(--text); }
.micro-table tbody tr:last-child td { border-bottom: none; }
.micro-table tbody tr:hover { background: rgba(127,127,127,.07); }
.micro-foot { margin-top: 16px; padding: 12px 14px; background: var(--grad-soft); border: 1px solid var(--border); border-radius: 12px; font-size: 13px; color: var(--muted); }
.micro-foot p { margin: 0; }

/* ---------- 实战例题（广西二级造价师·安装工程） ---------- */
.exam-q { margin: 12px 0; padding: 14px 16px; background: var(--card); border: 1px solid var(--border); border-radius: 12px; }
.exam-q__t { margin: 0 0 8px; font-weight: 600; color: var(--text); }
.exam-q__opts { margin: 6px 0; padding-left: 20px; }
.exam-q__opts li { margin: 4px 0; }
.exam-q__ans { margin-top: 8px; }
.exam-q__ans summary { cursor: pointer; color: var(--primary); font-weight: 700; font-size: 13.5px; user-select: none; list-style: none; }
.exam-q__ans summary::-webkit-details-marker { display: none; }
.exam-q__ans summary::before { content: "▸ "; }
.exam-q__ans[open] summary::before { content: "▾ "; }
.exam-q__ans summary:hover { text-decoration: underline; }
.exam-q__key { margin: 8px 0 2px; }
.exam-q__exp { margin: 2px 0 0; color: var(--muted); font-size: 13.5px; line-height: 1.7; }

/* ---------- 实战例题：可交互答题（选项点选 / 提交判分 / 重做） ---------- */
.exam-q__opts { display: grid; grid-template-columns: 1fr; gap: 8px; margin: 10px 0; padding: 0; }
.exam-opt {
  display: block; width: 100%; text-align: left; padding: 10px 14px;
  border: 1.5px solid var(--border); border-radius: 10px; background: var(--card);
  color: var(--text); font-size: 14px; font-weight: 500; cursor: pointer;
  font-family: inherit; transition: all .18s cubic-bezier(.16,1,.3,1);
}
.exam-opt:hover { border-color: var(--primary); transform: translateY(-1px); box-shadow: 0 4px 12px rgba(37,99,235,.12); }
.exam-opt.selected { border-color: var(--primary); background: var(--grad-soft); box-shadow: 0 0 0 3px rgba(37,99,235,.15); }
.exam-opt.correct { border-color: #16a34a; background: rgba(22,163,74,.12); color: #15803d; font-weight: 700; }
.exam-opt.wrong { border-color: #dc2626; background: rgba(220,38,38,.10); color: #b91c1c; }
.exam-opt:disabled { cursor: default; opacity: .92; transform: none; box-shadow: none; }
.exam-q__foot { display: flex; align-items: center; gap: 12px; margin: 12px 0 4px; }
.exam-feedback { font-size: 13.5px; font-weight: 700; }
.exam-feedback.ok { color: #16a34a; }
.exam-feedback.warn { color: #dc2626; }
.exam-q__ans[hidden] { display: none; }
.exam-q__ans { margin-top: 10px; padding: 10px 14px; background: var(--grad-soft); border-radius: 10px; border: 1px dashed var(--border); }

/* ---------- 卡片来源标记（颜色区分：AI 紫 / 慕课 蓝 / 原创 绿） ---------- */
.res-origin { display: inline-block; border-radius: 999px; padding: 2px 10px; font-size: 12px; font-weight: 700; letter-spacing: .2px; line-height: 1.6; }
.res-origin.o-ai { background: rgba(139,92,246,.16); color: #7c3aed; }
.res-origin.o-mooc { background: rgba(37,99,235,.14); color: #1d4ed8; }
.res-origin.o-orig { background: rgba(16,185,129,.16); color: #059669; }
/* 慕课深链按钮（蓝）沿用 .mooc-chip，强化文案 */
.mooc-chip { font-weight: 700; }

/* ---------- 教师端按来源分组 圆点配色 ---------- */
.tres-head .rg-dot.o-ai { background: #7c3aed; }
.tres-head .rg-dot.o-mooc { background: #1d4ed8; }
.tres-head .rg-dot.o-orig { background: #059669; }

/* ---------- 子区块标题（主从区分） ---------- */
.sub-sec { font-size: 16px; font-weight: 800; margin: 4px 0 12px; display: flex; align-items: center; gap: 9px; color: var(--primary); }
.sub-sec::before { content: ""; width: 4px; height: 17px; border-radius: 4px; background: var(--grad-hero); display: inline-block; }

/* ---------- 学生端学习中心：两级标题（模块 → 类型） ---------- */
.learn-l1 { display: flex; align-items: center; gap: 10px; margin: 22px 0 6px; font-size: 20px; font-weight: 800; color: var(--text); letter-spacing: .3px; }
.learn-l1.l1-main { color: #1d4ed8; }
.learn-l1.l1-extra { color: #7c3aed; }
.learn-l1 .l1-dot { width: 11px; height: 11px; border-radius: 50%; flex: none; }
.learn-l1.l1-main .l1-dot { background: #1d4ed8; box-shadow: 0 0 0 4px rgba(29,78,216,.14); }
.learn-l1.l1-extra .l1-dot { background: #7c3aed; box-shadow: 0 0 0 4px rgba(124,58,237,.14); }
.learn-l1 .l1-count { margin-left: auto; font-size: 12.5px; font-weight: 600; color: var(--muted); background: rgba(15,23,42,.06); border-radius: 999px; padding: 2px 10px; }
.learn-l2 { display: flex; align-items: center; gap: 9px; margin: 14px 0 2px; font-size: 14.5px; font-weight: 700; color: var(--muted); }
.learn-l2 .l2-bar { width: 3px; height: 15px; border-radius: 3px; background: var(--grad-hero); display: inline-block; }
.learn-l2 .l2-count { font-size: 12px; font-weight: 600; color: var(--muted); background: rgba(15,23,42,.05); border-radius: 999px; padding: 1px 8px; }

/* ---------- 教师端模块内：按来源两类分组小标题（引用慕课蓝 / AI原创紫 / 其他原创绿） ---------- */
.tres-sub { display: flex; align-items: center; gap: 8px; margin: 16px 0 2px; font-weight: 800; font-size: 14.5px; letter-spacing: .02em; }
.tres-sub:first-child { margin-top: 8px; }
.tres-sub .rg-dot { width: 10px; height: 10px; border-radius: 50%; flex: none; }
.tres-sub.o-mooc { color: #1d4ed8; }
.tres-sub.o-mooc .rg-dot { background: #1d4ed8; box-shadow: 0 0 0 4px rgba(29,78,216,.14); }
.tres-sub.o-ai { color: #7c3aed; }
.tres-sub.o-ai .rg-dot { background: #7c3aed; box-shadow: 0 0 0 4px rgba(124,58,237,.14); }
.tres-sub.o-orig { color: #059669; }
.tres-sub.o-orig .rg-dot { background: #059669; box-shadow: 0 0 0 4px rgba(5,150,105,.14); }
.tres-sub .rg-count { margin-left: 2px; font-size: 12px; font-weight: 700; color: var(--muted); background: var(--grad-soft, rgba(15,23,42,.06)); border: 1px solid var(--border, transparent); border-radius: 999px; padding: 1px 9px; }

/* ============ 课堂小游戏：列项大作战 ============ */
.game-wrap { --lx: #f43f5e; --lx-2: #fb7185; padding: 2px 0; }
.lx-head { display: flex; flex-direction: column; gap: 6px; margin-bottom: 12px; }
.lx-title { font-size: 20px; font-weight: 800; background: linear-gradient(135deg, var(--lx), var(--lx-2)); -webkit-background-clip: text; background-clip: text; color: transparent; }
.lx-meta { display: flex; flex-wrap: wrap; gap: 10px; font-size: 13px; color: var(--muted); }
.lx-standard { background: var(--grad-soft, rgba(15,23,42,.06)); border: 1px solid var(--border); border-radius: 999px; padding: 3px 12px; }
.lx-best { background: rgba(244,63,94,.10); border: 1px solid rgba(244,63,94,.25); color: var(--lx); border-radius: 999px; padding: 3px 12px; font-weight: 600; }
.lx-best b { font-size: 15px; }

.lx-timerbar { height: 8px; border-radius: 999px; background: var(--border); overflow: hidden; margin: 10px 0 14px; }
.lx-timerfill { height: 100%; width: 100%; border-radius: 999px; background: linear-gradient(90deg, #22c55e, #eab308 60%, var(--lx)); transition: width 1s linear; }

.lx-hud { display: flex; gap: 10px; flex-wrap: wrap; margin-bottom: 12px; }
.lx-hud > span { background: var(--card); border: 1px solid var(--border); border-radius: 12px; padding: 7px 14px; font-size: 13.5px; color: var(--muted); font-weight: 600; }
.lx-hud b { color: var(--text); font-size: 17px; margin-left: 4px; }
.lx-score b { color: var(--lx); }
.lx-score b.pop { animation: lxPop .45s ease; }
@keyframes lxPop { 0% { transform: scale(1); } 40% { transform: scale(1.45); color: #22c55e; } 100% { transform: scale(1); } }

.lx-scenario { background: var(--grad-soft, rgba(15,23,42,.05)); border: 1px solid var(--border); border-left: 4px solid var(--lx); border-radius: 12px; padding: 12px 14px; line-height: 1.75; color: var(--text); margin: 0 0 14px; }

.lx-pool { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px; }
@media (max-width: 640px) { .lx-pool { grid-template-columns: 1fr; } }
.lx-item { display: flex; align-items: center; gap: 10px; text-align: left; padding: 12px 14px; border-radius: 14px; border: 1.5px solid var(--border); background: var(--card); color: var(--text); font-size: 14px; font-weight: 600; cursor: pointer; transition: transform .18s cubic-bezier(.16,1,.3,1), box-shadow .18s, border-color .18s, background .18s; }
.lx-item:hover { transform: translateY(-2px); box-shadow: 0 10px 24px rgba(15,23,42,.12); border-color: rgba(244,63,94,.4); }
.lx-item .lx-check { width: 22px; height: 22px; flex: none; border-radius: 50%; border: 2px solid var(--muted); display: inline-flex; align-items: center; justify-content: center; font-size: 13px; color: var(--muted); transition: all .15s; }
.lx-item.on { border-color: var(--lx); background: rgba(244,63,94,.10); box-shadow: 0 8px 22px rgba(244,63,94,.18); }
.lx-item.on .lx-check { background: var(--lx); border-color: var(--lx); color: #fff; }

.lx-actions { display: flex; gap: 10px; margin: 16px 0 4px; }

.lx-result { margin-top: 14px; animation: lxFade .4s ease; }
@keyframes lxFade { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }
.lx-summary { display: grid; grid-template-columns: repeat(4, 1fr); gap: 10px; margin-bottom: 12px; }
@media (max-width: 640px) { .lx-summary { grid-template-columns: repeat(2, 1fr); } }
.lx-stat { background: var(--card); border: 1px solid var(--border); border-radius: 14px; padding: 12px; text-align: center; }
.lx-stat b { display: block; font-size: 26px; font-weight: 800; color: var(--text); line-height: 1.1; }
.lx-stat span { font-size: 12px; color: var(--muted); }
.lx-stat.hi b { color: var(--lx); }
.lx-stat.bad b { color: var(--lx); }
.lx-stat.miss b { color: #eab308; }

.lx-list { list-style: none; padding: 0; margin: 4px 0 0; display: flex; flex-direction: column; gap: 8px; }
.lx-row { border: 1px solid var(--border); border-left: 4px solid var(--muted); border-radius: 10px; padding: 10px 12px; background: var(--card); }
.lx-row.ok { border-left-color: #22c55e; }
.lx-row.miss { border-left-color: #eab308; }
.lx-row.bad { border-left-color: var(--lx); }
.lx-row.skip { opacity: .72; }
.lx-row-h { display: flex; align-items: center; justify-content: space-between; gap: 10px; }
.lx-row-h b { font-size: 14px; color: var(--text); }
.lx-mark { font-size: 12px; font-weight: 700; padding: 2px 9px; border-radius: 999px; white-space: nowrap; }
.lx-row.ok .lx-mark { color: #16a34a; background: rgba(34,197,94,.12); }
.lx-row.miss .lx-mark { color: #ca8a04; background: rgba(234,179,8,.14); }
.lx-row.bad .lx-mark { color: var(--lx); background: rgba(244,63,94,.12); }
.lx-row.skip .lx-mark { color: var(--muted); background: rgba(100,116,139,.12); }
.lx-reason { font-size: 12.5px; color: var(--muted); line-height: 1.6; margin-top: 5px; }

/* ===== 诊断报告 · 薄弱知识点关联资源推荐 ===== */
.diag-kp { border-radius: 12px; }
.diag-kp.has-rec { background: rgba(239, 68, 68, .04); padding: 2px 10px 10px; margin: 4px -10px; }
.diag-rec { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; margin: 2px 0 4px 200px; }
.diag-rec-h { font-size: 12px; font-weight: 600; color: var(--accent); background: var(--grad-soft); border-radius: 999px; padding: 3px 10px; white-space: nowrap; }
.diag-rec-item { max-width: 340px; padding: 6px 10px !important; font-size: 12.5px !important; }
.diag-rec-t { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.diag-rec-d { color: var(--muted); font-size: 11.5px; margin-left: 4px; white-space: nowrap; }
@media (max-width: 900px) { .diag-rec { margin-left: 0; } .diag-rec-item { max-width: 100%; } }

/* ============================================================
 * 双层导航：左侧一级菜单 + 顶部二级菜单
 * 仅对「配置了导航树」的角色启用（当前为教师端）；
 * 其余角色保持原单层顶栏（app-shell 带 layout-top 时侧栏隐藏）。
 * ============================================================ */
.app-shell { display: flex; align-items: stretch; min-height: 100vh; }
.app-shell.layout-top .sidebar { display: none; }
.main-col { flex: 1 1 auto; min-width: 0; display: flex; flex-direction: column; }
.main-col .container { width: 100%; }

/* ---------- 一级菜单（左侧） ---------- */
.sidebar {
  flex: 0 0 210px; width: 210px;
  position: sticky; top: 0; align-self: flex-start; height: 100vh;
  display: flex; flex-direction: column; gap: 5px;
  padding: 18px 12px;
  background: var(--card); backdrop-filter: blur(18px) saturate(160%);
  border-right: 1px solid var(--border);
  overflow-y: auto; z-index: 20;
}
.side-head { padding: 0 10px 12px; margin-bottom: 6px; border-bottom: 1px solid var(--border); }
.side-role { font-size: 12.5px; font-weight: 700; letter-spacing: .5px; color: var(--muted); }
.side-group {
  display: flex; align-items: center; gap: 11px; width: 100%;
  padding: 11px 12px; border: none; text-align: left; cursor: pointer;
  border-radius: 12px; background: transparent; color: var(--muted);
  font-family: inherit; font-size: 14px; font-weight: 600; line-height: 1.2;
  transition: transform .18s cubic-bezier(.16,1,.3,1), background .2s, color .2s, box-shadow .2s;
}
.side-group svg { flex: 0 0 18px; width: 18px; height: 18px; }
.side-group span { white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.side-group:hover { background: var(--grad-soft); color: var(--primary); transform: translateX(2px); }
.side-group.active { background: var(--grad-hero); color: #fff; box-shadow: 0 8px 20px rgba(37,99,235,.32); }
.side-group.active:hover { transform: none; }
.side-group:focus-visible { outline: 2px solid var(--primary); outline-offset: 2px; }

/* 侧栏模式下顶栏：二级菜单横向可滚动，不换行挤压品牌 */
.layout-sidebar .topbar { padding: 11px 22px; }
.layout-sidebar .nav { flex-wrap: nowrap; overflow-x: auto; scrollbar-width: none; }
.layout-sidebar .nav::-webkit-scrollbar { display: none; }

@media (max-width: 1080px) {
  .sidebar { flex-basis: 70px; width: 70px; padding: 16px 8px; }
  .side-head { display: none; }
  .side-group { justify-content: center; padding: 12px 0; }
  .side-group span { display: none; }
  .side-group:hover { transform: none; }
}
@media (max-width: 720px) {
  .layout-sidebar .topbar { flex-wrap: wrap; }
  .layout-sidebar .nav { width: 100%; order: 3; border-top: 1px solid var(--border); padding-top: 8px; }
  .main-col .container { padding: 0 14px 50px; }
  /* 窄屏回收顶栏空间：用户名只留头像，重置按钮隐藏（桌面端不受影响） */
  .layout-sidebar .user-tag span:not(.mini-avatar) { display: none; }
  .layout-sidebar .user-tag { padding: 5px; }
  .layout-sidebar #resetBtn { display: none; }
}