/* ═══════════════════════════════════════════════════════════
   build.css —— 实战主线「你的第一个能干活的 Agent」相关组件

   服务四类页面，PlayGround（playground/build.html）与正式页共用同一份：
     build-1 ~ build-6   每章末尾的「你现在能做什么」
     build-log.html      Agent 建造日志
     roadmap.html        三条角色学习路线
     learn.html          篇章开头的「我在哪」锚点横幅

   配色只用一种色系（靛蓝 --bd），冷暖状态借 lesson.css 的语义色。
   动画只动 transform / opacity，避免重排。
   ═══════════════════════════════════════════════════════════ */

:root {
  --bd: #4f46e5;                      /* 主线主色，靛蓝 */
  --bd-deep: #3730a3;
  --bd-soft: rgba(79, 70, 229, 0.08);
  --bd-line: rgba(79, 70, 229, 0.22);
}

/* 关掉动画偏好：所有过渡直接给终态，不做位移 */
@media (prefers-reduced-motion: reduce) {
  .bd-anim, .bd-anim * { transition: none !important; animation: none !important; }
}

/* ───────────────────────────────────────────
   1. 动手任务卡（三档难度）
   ─────────────────────────────────────────── */
.bd-tasks { display: flex; flex-direction: column; gap: 13px; }

.bd-task {
  display: grid; grid-template-columns: auto 1fr; gap: 16px;
  background: var(--card); border: 1.5px solid var(--border);
  border-radius: 16px; padding: 19px 22px;
  box-shadow: var(--shadow-card);
  cursor: pointer; transition: border-color .2s, background .2s, transform .2s, box-shadow .2s;
}
.bd-task:hover {
  border-color: rgba(79, 70, 229, .4);
  transform: translateY(-2px);
  box-shadow: 0 10px 26px rgba(28, 25, 90, .09);
}
.bd-task.done { border-color: rgba(22, 163, 74, .4); background: rgba(22, 163, 74, .03); }

.bd-check {
  width: 28px; height: 28px; border-radius: 50%; margin-top: 1px;
  border: 2px solid rgba(79, 70, 229, .35); flex-shrink: 0;
  display: flex; align-items: center; justify-content: center;
  color: #fff; transition: background .2s, border-color .2s, transform .2s;
}
.bd-task:hover .bd-check { border-color: var(--bd); }
.bd-check svg { width: 15px; height: 15px; opacity: 0; transform: scale(.5); transition: opacity .18s, transform .18s; }
.bd-task.done .bd-check { background: var(--success); border-color: var(--success); }
.bd-task.done .bd-check svg { opacity: 1; transform: scale(1); }

.bd-task-head { display: flex; align-items: center; gap: 9px; flex-wrap: wrap; margin-bottom: 5px; }
.bd-task-head h4 { font-size: 15px; font-weight: 800; color: var(--text); }
.bd-task.done .bd-task-head h4 { color: var(--sub); text-decoration: line-through; text-decoration-color: rgba(0,0,0,.2); }
.bd-task p { font-size: 13.5px; color: var(--sub); line-height: 1.8; }

/* 难度徽章：三档，只用色深浅区分，不换色系 */
.bd-level {
  font-size: 11px; font-weight: 800; letter-spacing: .3px;
  padding: 2px 9px; border-radius: 999px; flex-shrink: 0;
}
.bd-level.lv1 { background: rgba(79, 70, 229, .08); color: var(--bd); }
.bd-level.lv2 { background: rgba(79, 70, 229, .15); color: var(--bd-deep); }
.bd-level.lv3 { background: var(--bd); color: #fff; }

/* 验收标准：折叠，点开才看 */
.bd-accept { margin-top: 10px; }
.bd-accept summary {
  font-size: 12.5px; font-weight: 700; color: var(--bd);
  cursor: pointer; list-style: none; display: inline-flex; align-items: center; gap: 5px;
}
.bd-accept summary::-webkit-details-marker { display: none; }
.bd-accept summary svg { width: 13px; height: 13px; transition: transform .2s; }
.bd-accept[open] summary svg { transform: rotate(90deg); }
.bd-accept .bd-accept-body {
  margin-top: 9px; padding: 12px 15px;
  background: var(--bd-soft); border-radius: var(--radius-sm);
  font-size: 13px; color: var(--text); line-height: 1.85;
}
.bd-accept .bd-accept-body b { color: var(--bd-deep); }

/* ───────────────────────────────────────────
   2. 进度环 + 计数
   ─────────────────────────────────────────── */
.bd-progress {
  display: flex; align-items: center; gap: 16px;
  background: linear-gradient(130deg, rgba(79, 70, 229, .07), rgba(79, 70, 229, .02));
  border: 1.5px solid var(--bd-line);
  border-radius: 16px; padding: 15px 20px;
  margin: 0 0 16px;
}
.bd-ring { width: 46px; height: 46px; flex-shrink: 0; transform: rotate(-90deg); }
.bd-ring circle { fill: none; stroke-width: 5.5; stroke-linecap: round; }
.bd-ring .bd-ring-bg { stroke: rgba(79, 70, 229, .14); }
.bd-ring .bd-ring-fg {
  stroke: var(--bd);
  transition: stroke-dashoffset .5s cubic-bezier(.34, 1.2, .64, 1), stroke .3s;
}
.bd-progress.all .bd-ring .bd-ring-fg { stroke: var(--success); }
.bd-progress-text { flex: 1; }
.bd-progress-text h4 { font-size: 14.5px; font-weight: 800; color: var(--text); margin-bottom: 3px; }
.bd-progress-text p { font-size: 13px; color: var(--sub); line-height: 1.7; }
.bd-progress.all .bd-progress-text h4 { color: var(--success); }

/* ───────────────────────────────────────────
   3. 里程碑轨道（build-log）
   ─────────────────────────────────────────── */
.bd-track { position: relative; padding: 6px 0 2px; margin: 20px 0 26px; }
.bd-track-line {
  position: absolute; left: 0; right: 0; top: 24px; height: 3px;
  background: rgba(0, 0, 0, .07); border-radius: 2px;
}
.bd-track-fill {
  position: absolute; left: 0; top: 0; height: 100%; width: 0;
  background: var(--bd); border-radius: 2px;
  transform-origin: left center;
  transition: width .55s cubic-bezier(.34, 1.1, .64, 1);
}
.bd-track-nodes { position: relative; display: flex; justify-content: space-between; }
.bd-node { display: flex; flex-direction: column; align-items: center; gap: 8px; flex: 1; }
.bd-node-dot {
  width: 36px; height: 36px; border-radius: 50%;
  background: var(--bg); border: 3px solid rgba(0, 0, 0, .1);
  display: flex; align-items: center; justify-content: center;
  font-size: 12.5px; font-weight: 900; color: var(--sub);
  transition: background .3s, border-color .3s, color .3s, transform .3s;
}
.bd-node.on .bd-node-dot {
  background: var(--bd); border-color: var(--bd); color: #fff;
  transform: scale(1.1);
}
.bd-node.cur .bd-node-dot {
  border-color: var(--bd); color: var(--bd-deep);
  box-shadow: 0 0 0 5px var(--bd-soft);
}
.bd-node-label {
  font-size: 11.5px; font-weight: 700; color: var(--sub);
  text-align: center; line-height: 1.5; max-width: 92px;
}
.bd-node.on .bd-node-label { color: var(--bd-deep); }

/* ───────────────────────────────────────────
   4. 里程碑填写卡（build-log）
   ─────────────────────────────────────────── */
.bd-ms {
  background: var(--card); border: 1.5px solid var(--border);
  border-radius: var(--radius); box-shadow: var(--shadow-card);
  margin-bottom: 14px; overflow: hidden;
}
.bd-ms.on { border-color: var(--bd-line); }
.bd-ms-head {
  display: grid; grid-template-columns: auto 1fr auto; gap: 13px; align-items: center;
  padding: 16px 20px; cursor: pointer; transition: background .18s;
}
.bd-ms-head:hover { background: var(--bd-soft); }
.bd-ms-no {
  width: 32px; height: 32px; border-radius: 10px;
  background: var(--bd-soft); color: var(--bd-deep);
  display: flex; align-items: center; justify-content: center;
  font-size: 12.5px; font-weight: 900;
}
.bd-ms.on .bd-ms-no { background: var(--bd); color: #fff; }
.bd-ms-title h4 { font-size: 15px; font-weight: 800; color: var(--text); margin-bottom: 2px; }
.bd-ms-title p { font-size: 12.5px; color: var(--sub); }
.bd-ms-toggle { width: 18px; height: 18px; color: var(--sub); transition: transform .22s; }
.bd-ms.open .bd-ms-toggle { transform: rotate(180deg); }
.bd-ms-body {
  max-height: 0; overflow: hidden;
  transition: max-height .3s ease;
}
.bd-ms.open .bd-ms-body { max-height: 620px; }
.bd-ms-inner { padding: 4px 20px 18px; border-top: 1px solid var(--border); }
.bd-ms-inner label {
  display: block; font-size: 12px; font-weight: 800; color: var(--sub);
  letter-spacing: .3px; margin: 14px 0 6px;
}
.bd-ms-inner textarea, .bd-ms-inner input[type="text"] {
  width: 100%; font-family: inherit; font-size: 13.5px; color: var(--text);
  background: var(--bg); border: 1.5px solid var(--border);
  border-radius: var(--radius-sm); padding: 10px 13px; line-height: 1.75;
  transition: border-color .18s; resize: vertical;
}
.bd-ms-inner textarea:focus, .bd-ms-inner input[type="text"]:focus {
  outline: none; border-color: var(--bd);
}
.bd-ms-hint { font-size: 12.5px; color: var(--sub); line-height: 1.8; margin-top: 6px; }
.bd-ms-hint b { color: var(--bd-deep); }

/* ───────────────────────────────────────────
   5. 路线卡（roadmap）
   ─────────────────────────────────────────── */
/* 四档路线两行两列。原来是三列，第四档「全都要」加进来后会孤零零掉到第二行，
   看着像加塞的补丁，其实它是阶梯的最后一级。 */
.bd-routes { display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px; }
/* 卡片数为奇数时最后一张跨满整行，避免半宽孤悬 */
.bd-routes .bd-route:nth-child(odd):last-child { grid-column: 1 / -1; }
.bd-route {
  background: var(--card); border: 1.5px solid var(--border);
  border-radius: var(--radius); padding: 22px 22px 20px;
  box-shadow: var(--shadow-card);
  cursor: pointer; transition: border-color .2s, transform .2s, box-shadow .2s;
  display: flex; flex-direction: column;
}
.bd-route:hover, .bd-route.on { border-color: var(--bd); transform: translateY(-3px); box-shadow: var(--shadow-pop); }
.bd-route-ic {
  width: 38px; height: 38px; border-radius: 11px; margin-bottom: 13px;
  background: var(--bd-soft); color: var(--bd);
  display: flex; align-items: center; justify-content: center;
}
.bd-route.on .bd-route-ic { background: var(--bd); color: #fff; }
.bd-route-ic svg { width: 19px; height: 19px; }
.bd-route h3 { font-size: 17px; font-weight: 900; color: var(--text); margin-bottom: 6px; }
.bd-route > p { font-size: 13px; color: var(--sub); line-height: 1.8; margin-bottom: 14px; flex: 1; }
.bd-route-meta { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 13px; }
.bd-route-meta span {
  font-size: 11.5px; font-weight: 800; padding: 3px 10px; border-radius: 999px;
  background: var(--bd-soft); color: var(--bd-deep);
}
.bd-route-cta {
  display: inline-flex; align-items: center; justify-content: center; gap: 6px;
  background: var(--bd); color: #fff; text-decoration: none;
  padding: 10px 18px; border-radius: 999px;
  font-size: 13.5px; font-weight: 800;
  transition: filter .15s;
}
.bd-route-cta:hover { filter: brightness(1.1); }
.bd-route-cta svg { width: 15px; height: 15px; }

/* ───────────────────────────────────────────
   6. 缩略课程地图：路线覆盖到哪些篇章
   ─────────────────────────────────────────── */
.bd-map { display: flex; flex-direction: column; gap: 9px; margin-top: 20px; }
.bd-map-row {
  display: grid; grid-template-columns: 96px 1fr auto; gap: 13px; align-items: center;
  padding: 11px 15px; border-radius: var(--radius-sm);
  background: var(--card); border: 1.5px solid var(--border);
  transition: border-color .28s, background .28s, opacity .28s;
}
.bd-map-row.dim { opacity: .38; }
.bd-map-row.hit { border-color: var(--bd); background: var(--bd-soft); }
/* 部分覆盖：路线标记下沉到主题级后，一个篇章可能只进来一半。
   给它一档介于全含和排除之间的弱高亮，虚线边表示这一章是被切过的。 */
.bd-map-row.part {
  border-color: color-mix(in srgb, var(--bd) 42%, transparent);
  border-style: dashed;
  background: color-mix(in srgb, var(--bd-soft) 55%, transparent);
}
.bd-map-no { font-size: 12px; font-weight: 800; color: var(--sub); }
.bd-map-row.hit .bd-map-no,
.bd-map-row.part .bd-map-no { color: var(--bd-deep); }
.bd-map-title { font-size: 13.5px; font-weight: 700; color: var(--text); }
.bd-map-title em {
  font-style: normal; margin-left: 7px; padding: 1px 6px;
  font-size: 11px; font-weight: 800; border-radius: 5px;
  color: #b45309; background: rgba(245, 158, 11, .13);
}
.bd-map-count { font-size: 12px; font-weight: 800; color: var(--sub); white-space: nowrap; }
.bd-map-row.hit .bd-map-count { color: var(--bd); }
.bd-map-row.part .bd-map-count { color: var(--bd-deep); }

/* ───────────────────────────────────────────
   7. 通用：重放按钮、动作条
   ─────────────────────────────────────────── */
.bd-replay {
  display: inline-flex; align-items: center; gap: 6px;
  background: none; border: 1.5px solid var(--border);
  border-radius: 999px; padding: 6px 14px;
  font-family: inherit; font-size: 12.5px; font-weight: 700; color: var(--sub);
  cursor: pointer; transition: border-color .15s, color .15s;
}
.bd-replay:hover { border-color: var(--bd); color: var(--bd); }
.bd-replay svg { width: 13px; height: 13px; transition: transform .4s; }
.bd-replay:active svg { transform: rotate(-180deg); }

.bd-actions { display: flex; gap: 10px; flex-wrap: wrap; align-items: center; margin-top: 18px; }
.bd-btn {
  display: inline-flex; align-items: center; gap: 7px;
  background: var(--bd); color: #fff; border: none; text-decoration: none;
  border-radius: 999px; padding: 11px 22px;
  font-family: inherit; font-size: 13.5px; font-weight: 800;
  cursor: pointer; transition: filter .15s, transform .15s;
}
.bd-btn:hover { filter: brightness(1.1); transform: translateY(-1px); }
.bd-btn.ghost { background: none; color: var(--bd); border: 1.5px solid var(--bd-line); }
.bd-btn.ghost:hover { background: var(--bd-soft); }
.bd-btn svg { width: 15px; height: 15px; }
.bd-btn[disabled] { opacity: .45; cursor: not-allowed; transform: none; filter: none; }

.bd-saved {
  font-size: 12.5px; font-weight: 700; color: var(--success);
  opacity: 0; transition: opacity .25s;
  display: inline-flex; align-items: center; gap: 5px;
}
.bd-saved.show { opacity: 1; }
.bd-saved svg { width: 13px; height: 13px; }

/* ───────────────────────────────────────────
   8. 模拟台：build-1~6 的交互演示共用外壳
   三种内核：chain（流水线逐段点亮）、runs（多次运行对比）、curve（曲线与阈值）
   ─────────────────────────────────────────── */
.bd-sim {
  background: var(--card); border: 1.5px solid var(--border);
  border-radius: 16px; box-shadow: 0 4px 18px rgba(28, 25, 90, .06);
  padding: 22px 24px; margin: 20px 0;
}
.bd-sim-head {
  display: flex; align-items: center; justify-content: space-between;
  gap: 12px; margin-bottom: 8px;
}
.bd-sim-head h4 {
  font-size: 15px; font-weight: 800; color: var(--text);
  display: flex; align-items: center; gap: 9px;
}
/* 标题前的小圆点：给模拟台一个「实验器材」的记号 */
.bd-sim-head h4::before {
  content: ''; width: 9px; height: 9px; border-radius: 50%; flex: none;
  background: var(--bd); box-shadow: 0 0 0 4px var(--bd-soft);
}
.bd-sim-tip { font-size: 12.5px; color: var(--sub); line-height: 1.8; margin-bottom: 16px; }
.bd-sim-tip b { color: var(--bd-deep); }
.bd-sim-foot {
  margin-top: 15px; padding-top: 13px; border-top: 1px dashed var(--border);
  font-size: 13px; color: var(--sub); line-height: 1.85;
}
.bd-sim-foot b { color: var(--bd-deep); }

/* 模式切换：分段控件样式，选中项白底浮起 */
.bd-modes {
  display: inline-flex; gap: 2px;
  background: rgba(28, 25, 90, .06);
  border-radius: 999px; padding: 4px; margin-bottom: 18px;
}
.bd-mode {
  border: none; background: none; font-family: inherit;
  font-size: 12.5px; font-weight: 800; color: var(--sub);
  padding: 7px 18px; border-radius: 999px; cursor: pointer;
  transition: background .18s, color .18s, box-shadow .18s;
}
.bd-mode:hover { color: var(--text); }
.bd-mode.on {
  background: #fff; color: var(--bd-deep);
  box-shadow: 0 1px 5px rgba(0, 0, 0, .14);
}

/* ── 9a. 流水线：步骤逐段点亮，可在任一段注入失败 ── */
.bd-chain { display: flex; align-items: stretch; gap: 0; flex-wrap: wrap; }
.bd-chain-step {
  flex: 1; min-width: 118px;
  border: 1.5px solid var(--border); border-radius: 13px;
  padding: 14px 15px; background: #fff;
  opacity: .4; transform: translateY(6px);
  transition: opacity .32s, transform .32s, border-color .32s, background .32s, box-shadow .32s;
}
.bd-chain-step.on {
  opacity: 1; transform: translateY(0);
  border-color: rgba(79, 70, 229, .45);
  box-shadow: 0 8px 20px rgba(79, 70, 229, .13);
}
.bd-chain-step.fail {
  opacity: 1; transform: translateY(0);
  border-color: rgba(220, 38, 38, .4);
  box-shadow: 0 8px 20px rgba(220, 38, 38, .1);
}
.bd-chain-step.skip { opacity: .22; }
.bd-chain-no {
  display: inline-flex; align-items: center; justify-content: center;
  width: 23px; height: 23px; border-radius: 8px;
  font-size: 10.5px; font-weight: 900; letter-spacing: .3px;
  background: rgba(28, 25, 90, .06); color: var(--sub);
  margin-bottom: 9px;
  transition: background .32s, color .32s;
}
.bd-chain-step.on .bd-chain-no { background: var(--bd); color: #fff; }
.bd-chain-step.fail .bd-chain-no { background: var(--danger); color: #fff; }
.bd-chain-step h5 { font-size: 13px; font-weight: 800; color: var(--text); margin-bottom: 4px; line-height: 1.5; }
.bd-chain-step p { font-size: 12px; color: var(--sub); line-height: 1.7; }
.bd-chain-arrow {
  display: flex; align-items: center; justify-content: center;
  width: 28px; flex-shrink: 0; color: rgba(0, 0, 0, .16);
  transition: color .32s, transform .32s;
}
.bd-chain-arrow svg { width: 16px; height: 16px; }
.bd-chain-arrow.on { color: var(--bd); transform: translateX(2px); }

/* 流水线结论条 */
.bd-verdict {
  display: flex; align-items: center; gap: 9px;
  margin-top: 16px; padding: 13px 17px; border-radius: var(--radius-sm);
  font-size: 13px; line-height: 1.8; font-weight: 700;
  opacity: 0; transform: translateY(5px);
  transition: opacity .3s, transform .3s;
}
.bd-verdict::before {
  content: ''; width: 8px; height: 8px; border-radius: 50%; flex: none;
}
.bd-verdict.show { opacity: 1; transform: translateY(0); }
.bd-verdict.pass { background: rgba(22, 163, 74, .08); border: 1px solid rgba(22, 163, 74, .22); color: #15803d; }
.bd-verdict.pass::before { background: var(--success); }
.bd-verdict.deny { background: rgba(220, 38, 38, .06); border: 1px solid rgba(220, 38, 38, .2); color: #b91c1c; }
.bd-verdict.deny::before { background: var(--danger); }

/* ── 9b. 多次运行：同一输入跑 N 次，看结果稳不稳 ── */
.bd-runs { display: flex; flex-direction: column; gap: 8px; }
.bd-run {
  display: grid; grid-template-columns: 46px 1fr auto; gap: 12px; align-items: center;
  padding: 12px 16px; border-radius: var(--radius-sm);
  background: #fff; border: 1.5px solid var(--border);
  box-shadow: var(--shadow-card);
  opacity: 0; transform: translateX(-8px);
  transition: opacity .3s, transform .3s, border-color .3s;
}
.bd-run.show { opacity: 1; transform: translateX(0); }
.bd-run-no {
  display: inline-flex; align-items: center; justify-content: center;
  height: 22px; border-radius: 7px; padding: 0 7px;
  font-size: 10.5px; font-weight: 900;
  background: rgba(28, 25, 90, .06); color: var(--sub);
}
.bd-run-out { font-size: 13px; color: var(--text); line-height: 1.7; }
.bd-run-flag {
  font-size: 11px; font-weight: 800; padding: 2px 9px; border-radius: 999px; white-space: nowrap;
}
.bd-run.ok { border-color: rgba(22, 163, 74, .32); }
.bd-run.ok .bd-run-flag { background: rgba(22, 163, 74, .1); color: #15803d; }
.bd-run.bad { border-color: rgba(220, 38, 38, .3); }
.bd-run.bad .bd-run-flag { background: rgba(220, 38, 38, .08); color: #b91c1c; }

.bd-score {
  display: flex; align-items: baseline; gap: 8px; margin-top: 14px;
  font-size: 13px; color: var(--sub);
}
.bd-score b { font-size: 26px; font-weight: 900; color: var(--bd); line-height: 1; }
.bd-score.good b { color: var(--success); }
.bd-score.bad b { color: var(--danger); }

/* ── 9c. 曲线：长跑过程中的用量与阈值 ── */
.bd-curve { position: relative; }
.bd-curve svg { width: 100%; height: 168px; display: block; overflow: visible; }
.bd-curve .bd-curve-line {
  fill: none; stroke: var(--bd); stroke-width: 2.4;
  stroke-linecap: round; stroke-linejoin: round;
}
.bd-curve .bd-curve-area { fill: var(--bd-soft); stroke: none; }
.bd-curve .bd-curve-thresh { stroke: var(--danger); stroke-width: 1.4; stroke-dasharray: 5 4; }
.bd-curve .bd-curve-grid { stroke: rgba(0, 0, 0, .07); stroke-width: 1; }
.bd-curve-legend { display: flex; gap: 18px; flex-wrap: wrap; margin-top: 12px; font-size: 12px; color: var(--sub); }
.bd-curve-legend i { display: inline-block; width: 16px; height: 3px; border-radius: 2px; margin-right: 6px; vertical-align: middle; }
.bd-curve-legend .lg-line i { background: var(--bd); }
.bd-curve-legend .lg-thresh i { background: var(--danger); }
.bd-curve-mark {
  font-size: 10.5px; font-weight: 800; fill: var(--sub);
}

/* ───────────────────────────────────────────
   9. build-N 页专用：顶部主线定位条 + 底部下一步
   定位条里嵌 .bd-track，节点按建造日志的真实填写情况点亮
   ─────────────────────────────────────────── */
/* 主线页面的 kicker 跟着主线色走，别和主题蓝混 */
.bd-page .lesson-header .kicker { color: var(--bd); }

/* 段落导语与强调框：lesson.css 的 .l-callout 是蓝色系，主线页面统一走靛蓝 */
.bd-lead { font-size: 15px; color: var(--text); line-height: 1.95; margin-bottom: 18px; }
.bd-lead b { color: var(--bd-deep); }

.bd-callout {
  display: grid; grid-template-columns: auto 1fr; gap: 15px;
  background: #fff;
  border: 1.5px solid var(--bd-line);
  border-radius: 16px;
  padding: 20px 22px;
  margin-top: 20px;
  box-shadow: var(--shadow-card);
}
.bd-callout-ic {
  width: 36px; height: 36px; border-radius: 11px; flex: none;
  background: var(--bd-soft); color: var(--bd);
  display: flex; align-items: center; justify-content: center;
}
.bd-callout-ic svg { width: 18px; height: 18px; }
.bd-callout h4 { font-size: 14px; font-weight: 800; color: var(--bd-deep); margin-bottom: 6px; }
.bd-callout p { font-size: 13.5px; color: var(--sub); line-height: 1.9; }
.bd-callout b { color: var(--bd-deep); }

/* 任务卡上的「适合谁」，跟难度徽章并排 */
.bd-who { font-size: 11.5px; color: var(--sub); font-weight: 600; }

/* 主线定位条：整页唯一的深色面板，一眼锚定「我在主线的哪一格」 */
.bd-here {
  position: relative; overflow: hidden;
  background: linear-gradient(130deg, #1e1b4b 0%, #312e81 58%, #3b3494 100%);
  border-radius: 18px;
  padding: 24px 28px 18px;
  margin-bottom: 32px;
  box-shadow: 0 14px 36px rgba(30, 27, 75, .28);
}
.bd-here::before {
  content: ''; position: absolute; right: -70px; top: -90px;
  width: 280px; height: 280px; border-radius: 50%;
  background: radial-gradient(closest-side, rgba(129, 140, 248, .38), transparent 70%);
  pointer-events: none;
}
.bd-here::after {
  content: ''; position: absolute; left: -50px; bottom: -110px;
  width: 220px; height: 220px; border-radius: 50%;
  background: radial-gradient(closest-side, rgba(99, 102, 241, .22), transparent 70%);
  pointer-events: none;
}
.bd-here > * { position: relative; z-index: 1; }
.bd-here-cap {
  display: flex; align-items: center; gap: 9px; flex-wrap: wrap;
  font-size: 13px; color: rgba(199, 210, 254, .78); line-height: 1.7;
  margin-bottom: 18px;
}
.bd-here-cap svg { width: 16px; height: 16px; stroke: #a5b4fc; flex: none; }
.bd-here-cap b { color: #fff; }
.bd-here .bd-track { margin: 0; }

/* 深色面板里的轨道配色 */
.bd-here .bd-track-line { background: rgba(255, 255, 255, .13); }
.bd-here .bd-track-fill { background: linear-gradient(90deg, #6366f1, #a5b4fc); }
.bd-here .bd-node-dot {
  background: rgba(255, 255, 255, .06);
  border-color: rgba(255, 255, 255, .22);
  color: rgba(199, 210, 254, .6);
}
.bd-here .bd-node.on .bd-node-dot { background: #a5b4fc; border-color: #c7d2fe; color: #1e1b4b; }
.bd-here .bd-node.cur .bd-node-dot {
  background: #312e81; border-color: #a5b4fc; color: #fff;
  animation: bd-pulse 2.4s ease-in-out infinite;
}
@keyframes bd-pulse {
  0%, 100% { box-shadow: 0 0 0 4px rgba(165, 180, 252, .18); }
  50% { box-shadow: 0 0 0 9px rgba(165, 180, 252, .07); }
}
@media (prefers-reduced-motion: reduce) {
  .bd-here .bd-node.cur .bd-node-dot { animation: none; box-shadow: 0 0 0 5px rgba(165, 180, 252, .16); }
}
.bd-here .bd-node-label { color: rgba(199, 210, 254, .5); }
.bd-here .bd-node.on .bd-node-label { color: #c7d2fe; }
.bd-here .bd-node.cur .bd-node-label { color: #fff; }

/* 底部下一步：和顶部定位条同款深色面板，首尾呼应 */
.bd-next {
  position: relative; overflow: hidden;
  display: flex; align-items: center; justify-content: space-between;
  gap: 20px; flex-wrap: wrap;
  background: linear-gradient(130deg, #312e81, #4338ca 65%, #4f46e5);
  border-radius: 18px;
  padding: 24px 28px;
  margin-top: 34px;
  box-shadow: 0 14px 36px rgba(49, 46, 129, .28);
}
.bd-next::before {
  content: ''; position: absolute; right: -60px; top: -80px;
  width: 240px; height: 240px; border-radius: 50%;
  background: radial-gradient(closest-side, rgba(165, 180, 252, .35), transparent 70%);
  pointer-events: none;
}
.bd-next > * { position: relative; z-index: 1; }
.bd-next-txt { flex: 1 1 320px; }
.bd-next-txt h4 { margin: 0 0 6px; font-size: 16.5px; font-weight: 900; color: #fff; }
.bd-next-txt p { margin: 0; font-size: 13px; color: rgba(224, 231, 255, .78); line-height: 1.8; }
.bd-next-go {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 12px 24px; border-radius: 999px;
  background: #fff; color: var(--bd-deep);
  font-size: 14px; font-weight: 900; text-decoration: none;
  box-shadow: 0 4px 14px rgba(0, 0, 0, .18);
  transition: transform .18s ease, box-shadow .18s ease;
}
.bd-next-go svg { width: 16px; height: 16px; stroke: currentColor; }
.bd-next-go:hover { transform: translateX(3px); box-shadow: 0 8px 22px rgba(0, 0, 0, .24); }

/* ───────────────────────────────────────────
   10. 移动端
   ─────────────────────────────────────────── */
@media (max-width: 768px) {
  .bd-here { padding: 16px 16px 8px; }
  .bd-next { padding: 18px 16px; }
  .bd-routes { grid-template-columns: 1fr; }
  .bd-node-label { font-size: 10px; max-width: 54px; }
  .bd-node-dot { width: 30px; height: 30px; font-size: 11px; }
  .bd-track-line { top: 21px; }
  .bd-map-row { grid-template-columns: 62px 1fr; row-gap: 4px; }
  .bd-map-count { grid-column: 2; }
  /* 小屏放不下横排流水线，改竖排，箭头转 90 度 */
  .bd-chain { flex-direction: column; }
  .bd-chain-arrow { width: 100%; height: 22px; transform: rotate(90deg); }
  .bd-run { grid-template-columns: 34px 1fr; row-gap: 4px; }
  .bd-run-flag { grid-column: 2; justify-self: start; }
}