/* ============================================================
   化学学科页 · 学习流程图 .chem-flow（2026-10-12 批153）
   母题承 .chem-flow/.cf-*：反应链 —— 六边形苯环底纹 + 实心六边形节点 + 化学键虚线
   命名空间 .chem-flow / .cf-*，只作用于化学页，不污染其他学科
   交互契约与数学版 v2 相同（主按钮列 + 上下左右拖拽），视觉独立防雷同
   配色语义：青灰(定位) → 青蓝(学懂) → 草绿(练熟) → 橙(修坑) → 青(记牢) → 绿(测赢)
   深浅色：浅色为主 + html[data-theme="dark"] 覆盖（不写死色，跟 --ink/--surface）
   ============================================================ */

/* ---- 容器：暖白底 + 六边形晶格底纹（苯环平铺，右上角一只烧瓶剪影） ---- */
.chem-flow{position:relative;overflow:hidden;border-radius:20px;margin:0 0 16px;padding:18px 22px 16px;
  background:#f7fcf9;border:1px solid #d5ecdf;
  box-shadow:0 14px 34px -26px rgba(16,185,129,.45)}
.chem-flow::before{content:'';position:absolute;inset:0;pointer-events:none;opacity:.8;
  background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='30' height='34' viewBox='0 0 30 34'%3E%3Cpath d='M15 2 26 8.5v13L15 28 4 21.5v-13z' fill='none' stroke='%2310B981' stroke-opacity='.12'/%3E%3C/svg%3E");
  background-size:30px 34px;background-repeat:repeat;
  -webkit-mask-image:radial-gradient(120% 130% at 100% 0%,#000 20%,transparent 88%);
  mask-image:radial-gradient(120% 130% at 100% 0%,#000 20%,transparent 88%)}
.chem-flow::after{content:'⚗️';position:absolute;top:8px;right:16px;font-size:44px;line-height:1;
  opacity:.08;pointer-events:none;filter:grayscale(30%)}
.chem-flow > *{position:relative;z-index:2}

/* ---- 头部：标题 + 副标 + 三个真源徽标 ---- */
.cf-head{display:flex;align-items:flex-end;gap:14px;flex-wrap:wrap}
.cf-hl{min-width:0;flex:1 1 320px}
.cf-title{margin:0;font-size:19px;font-weight:800;letter-spacing:-.2px;color:#0e2620;
  display:flex;align-items:center;gap:8px}
.cf-title .cf-em{background:linear-gradient(120deg,#10B981 0%,#0E9494 55%,#2E7DB8 100%);
  -webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent;color:transparent}
.cf-title .cf-ax{display:inline-flex;align-items:center;justify-content:center;
  padding:3px 9px;border-radius:999px;font-size:11px;font-weight:700;letter-spacing:.3px;
  color:#0d8a62;background:rgba(16,185,129,.1);border:1px solid rgba(16,185,129,.26)}
.cf-sub{margin:7px 0 0;font-size:13px;line-height:1.75;color:#6f8378;max-width:640px}
.cf-metrics{display:flex;gap:9px;flex:0 0 auto}
.cf-metric{min-width:76px;padding:7px 12px;border-radius:12px;text-align:center;
  background:#f2faf6;border:1px solid #dcefe4}
.cf-metric b{display:block;font-size:19px;font-weight:800;line-height:1.25;color:#0e2620;
  font-variant-numeric:tabular-nums}
.cf-metric span{display:block;margin-top:2px;font-size:11.5px;color:#6f8378}

/* ---- 六环主轴：反应链列（auto-fit 保证 1440 视口六列一行） ---- */
.cf-axis{display:grid;grid-template-columns:repeat(auto-fit,minmax(min(100%,104px),1fr));
  gap:10px;margin-top:16px}
.cf-col{/*[批168] 列卡片透明：动线走下层时只被按钮本身挡住*/--nbg:position:relative;display:flex;flex-direction:column;align-items:flex-start;
  min-width:0;padding:11px 10px 10px;border-radius:14px;background:transparent;border:1px solid #dcefe4;
  transition:transform .16s ease,box-shadow .16s ease,border-color .16s ease}
.cf-col:hover{background:rgba(46,125,184,.045);border-color:var(--c);box-shadow:0 13px 26px -16px rgba(16,185,129,.5)}
/* 化学键线段：每列自带一段（虚线 = 化学键），首尾各取一半 —— 换行时每行仍自成一条链 */
.cf-track{position:absolute;top:29px;left:0;right:0;height:0;pointer-events:none;z-index:0;
  border-top:2px dotted;
  border-image:linear-gradient(90deg,#4E7A8A 0%,#2E7DB8 24%,#569A2E 44%,#E85A28 64%,#0E9494 82%,#1F8F62 100%) 1;
  opacity:.4}
.cf-col:first-child .cf-track{left:50%}
.cf-col:last-child .cf-track{right:50%}
/* 反应节点：实心六边形（苯环母题差异点，白字编号） */
.cf-dot{position:relative;z-index:2;flex:0 0 auto;width:30px;height:33px;margin:2px 0 1px;
  display:flex;align-items:center;justify-content:center;
  font-size:14px;font-weight:800;color:#fff;background:var(--c);
  clip-path:polygon(25% 6.7%,75% 6.7%,100% 50%,75% 93.3%,25% 93.3%,0% 50%);
  transition:filter .16s ease}
.cf-col:hover .cf-dot{filter:brightness(1.12)}
.cf-name{position:relative;z-index:2;margin-top:9px;font-size:15px;font-weight:800;color:#0e2620;
  letter-spacing:-.1px}
.cf-desc{margin-top:6px;font-size:12px;line-height:1.65;color:#68796e}

/* ---- 按钮列：每列第 1 个 = 主按钮（实心主色 + 箭头）；徽标 = 真源数字 ---- */
.cf-btns{display:flex;flex-direction:column;gap:6px;width:100%;margin-top:10px}
.cf-btn{position:relative;z-index:2;display:flex;align-items:center;justify-content:space-between;gap:5px;
  width:100%;padding:7px 9px;border-radius:9px;font-size:12px;font-weight:700;text-decoration:none;color:#3c5648;
  background:#f1f9f4;border:1px solid #dcefe4;cursor:grab;font-family:inherit;line-height:1.4;text-align:left;
  transition:background .15s ease,color .15s ease,border-color .15s ease,box-shadow .15s ease,transform .15s ease}
.cf-btn:hover{background:#fff;border-color:var(--c);color:var(--c);transform:translateY(-1px)}
.cf-btn:active{cursor:grabbing}
.cf-btn-main{color:#fff;background:var(--c);border-color:transparent;box-shadow:0 8px 16px -9px var(--c)}
.cf-btn-main:hover{background:var(--c);color:#fff;filter:brightness(1.07);transform:translateY(-1px)}
.cf-btn-main::after{content:'';flex:0 0 auto;width:11px;height:11px;background:currentColor;opacity:.9;
  -webkit-mask:no-repeat center/contain url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23000' stroke-width='2.6' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M5 12h14M13 5l7 7-7 7'/%3E%3C/svg%3E");
  mask:no-repeat center/contain url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23000' stroke-width='2.6' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M5 12h14M13 5l7 7-7 7'/%3E%3C/svg%3E")}
.cf-badge{position:absolute;top:-7px;right:5px;z-index:3;font-style:normal;font-size:10px;font-weight:800;
  line-height:1;padding:3px 6px;border-radius:999px;background:#fff;color:var(--c);white-space:nowrap;
  border:1px solid var(--c);font-variant-numeric:tabular-nums;box-shadow:0 2px 6px -3px rgba(16,185,129,.45)}
.cf-btn.cf-dragging{opacity:.38}
.cf-col.cf-over{border-color:var(--c)}
.cf-btn.cf-ins-top{box-shadow:inset 0 2px 0 var(--c)}
.cf-btn span{flex:1 1 0%;min-width:0;word-break:break-all;text-align:left}

/* ---- 底部：聊思路 · 看结果 · 找同伴（芯片行） ---- */
.cf-foot{display:flex;align-items:center;gap:5px;flex-wrap:wrap;
  margin-top:14px;padding-top:12px;border-top:1px dashed #dcefe4}
.cf-foot-lab{flex:0 0 auto;font-size:11px;font-weight:700;color:#8fa095;letter-spacing:0}
.cf-chip{display:inline-flex;align-items:center;gap:4px;padding:4px 8px;border-radius:999px;
  font-size:11.5px;font-weight:700;color:#3f6353;text-decoration:none;
  background:#f2faf6;border:1px solid #dcefe4;
  transition:background .15s ease,color .15s ease,border-color .15s ease,transform .15s ease}
.cf-chip:hover{background:#0d8a62;color:#fff;border-color:transparent;transform:translateY(-1px)}
.cf-sep{flex:0 0 auto;width:1px;height:15px;background:#dcefe4;margin:0 3px}
.cf-hint{position:relative;z-index:2;margin-top:11px;font-size:11.5px;line-height:1.6;color:#8fa095}

/* ---- 窄屏 ---- */
@media (max-width:900px){
  .chem-flow{padding:16px 15px 14px}
  .cf-metrics{flex-wrap:wrap}
  .cf-axis{grid-template-columns:repeat(auto-fit,minmax(min(100%,150px),1fr))}
}

/* ============================================================
   深色：夜晶格（苯环留、键留、底换深翠）
   ============================================================ */
html[data-theme="dark"] .chem-flow{
  background:var(--surface,#14201b);border-color:var(--hair-strong,rgba(255,255,255,.14));
  box-shadow:0 14px 34px -26px rgba(0,0,0,.66)}
html[data-theme="dark"] .chem-flow::before{
  background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='30' height='34' viewBox='0 0 30 34'%3E%3Cpath d='M15 2 26 8.5v13L15 28 4 21.5v-13z' fill='none' stroke='%2334d399' stroke-opacity='.16'/%3E%3C/svg%3E")}
html[data-theme="dark"] .chem-flow::after{opacity:.12}
html[data-theme="dark"] .cf-title{color:var(--ink,#fff)}
html[data-theme="dark"] .cf-title .cf-ax{color:#5eead4;background:rgba(52,211,153,.12);
  border-color:rgba(52,211,153,.3)}
html[data-theme="dark"] .cf-sub{color:var(--ink-3)}
html[data-theme="dark"] .cf-metric{background:rgba(255,255,255,.05);
  border-color:var(--hair-strong,rgba(255,255,255,.13))}
html[data-theme="dark"] .cf-metric b{color:var(--ink,#fff)}
html[data-theme="dark"] .cf-metric span{color:var(--ink-3)}
html[data-theme="dark"] .cf-col{--nbg:var(--surface,#1E1B2E);background:transparent;border-color:var(--hair-strong,rgba(255,255,255,.13))}
html[data-theme="dark"] .cf-col:hover{background:rgba(255,255,255,.045);border-color:var(--c);box-shadow:0 13px 26px -16px rgba(0,0,0,.65)}
html[data-theme="dark"] .cf-name{color:var(--ink,#fff)}
html[data-theme="dark"] .cf-desc{color:var(--ink-3)}
html[data-theme="dark"] .cf-btn{color:#c2d4c9;background:rgba(255,255,255,.05);
  border-color:rgba(255,255,255,.14)}
html[data-theme="dark"] .cf-btn:hover{background:rgba(255,255,255,.11);border-color:var(--c);color:#e9f5ee;transform:translateY(-1px)}
html[data-theme="dark"] .cf-btn-main{color:#fff;background:var(--c);border-color:transparent}
html[data-theme="dark"] .cf-btn-main:hover{background:var(--c);color:#fff;filter:brightness(1.1)}
html[data-theme="dark"] .cf-badge{background:#16241d;color:#cde8da;border-color:rgba(255,255,255,.24);box-shadow:0 2px 6px -3px rgba(0,0,0,.55)}
html[data-theme="dark"] .cf-btn-main .cf-badge{background:rgba(255,255,255,.25);color:#fff}
html[data-theme="dark"] .cf-foot{border-top-color:var(--hair-strong,rgba(255,255,255,.13))}
html[data-theme="dark"] .cf-foot-lab{color:var(--ink-3,#8a93ad)}
html[data-theme="dark"] .cf-chip{background:rgba(255,255,255,.05);border-color:rgba(255,255,255,.14);color:#c2d4c9}
html[data-theme="dark"] .cf-chip:hover{background:#0d8a62;color:#fff;border-color:transparent}
html[data-theme="dark"] .cf-sep{background:rgba(255,255,255,.14)}
html[data-theme="dark"] .cf-hint{color:var(--ink-3,#8a93ad)}
html[data-theme="dark"] .cf-track{opacity:.55}

/* ============================================================
   [批168] 六步动线（化学 · 电子轨道母题）
   交互契约与数学/英语版完全一致：动线连「按钮 → 按钮」，走列卡片**下层**——
   本段上方已把 .cf-col 改成透明，线只在按钮处被挡，列内空白与列间缝隙全程可见。
   （英语页看得清正是这个原因；此前各科列卡片是实心色，下层线被整列遮死）
   渐变 = 本科六环自身配色，跨科不雷同；箭头只在跨环弧上（同列直连段不画，避免浮点瑕疵）
   ============================================================ */
.cf-flow-wrap{position:relative}
.cf-flow{position:absolute;top:0;left:0;z-index:0;pointer-events:none;overflow:visible}
.cf-base{fill:none;stroke:#E2EDF5;stroke-width:3;stroke-linecap:round;opacity:.8}
.cf-arc{fill:none;stroke:url(#cfGrad);stroke-width:3;stroke-linecap:round;
  filter:drop-shadow(0 1px 3px rgba(46,125,184,.26))}
.cf-flowdash{fill:none;stroke:#fff;stroke-width:2.6;stroke-linecap:round;
  stroke-dasharray:16 58;animation:cfFlow 1.7s linear infinite}
.cf-head{fill:#2E7DB8}
@keyframes cfFlow{from{stroke-dashoffset:0}to{stroke-dashoffset:-74}}

/* 动线上的节点：命中高亮 / 未命中淡化 */
.cf-btn.is-active{border-color:var(--c);
  box-shadow:0 0 0 2px var(--c),0 14px 26px -14px rgba(46,125,184,.55);transform:translateY(-1px)}
.cf-btn.is-dim{opacity:.42;filter:saturate(.55)}
.cf-btn.is-dim:hover{opacity:.75}

/* 环节正式名辅注（诊断/学习/练习/纠错/复习/测验）+ 8 张核心能力卡小点 */
.cf-form{display:block;margin-top:1px;font-size:10.5px;font-weight:600;font-style:normal;color:#68796e;letter-spacing:.5px}
.cf-core-dot{flex:0 0 auto;width:5px;height:5px;border-radius:50%;background:#2E7DB8;
  box-shadow:0 0 0 2px rgba(46,125,184,.18)}
.cf-btn-main .cf-core-dot{background:#fff;box-shadow:0 0 0 2px rgba(255,255,255,.4)}

/* 今天想怎么走 · 动线芯片 */
.cf-routes{position:relative;z-index:3;display:flex;align-items:center;gap:7px;flex-wrap:wrap;margin-top:13px}
.cf-routes-lab{flex:0 0 auto;font-size:12px;font-weight:800;color:#0e2620;letter-spacing:.2px}
.cf-route{appearance:none;cursor:pointer;font-family:inherit;font-size:12px;font-weight:700;color:#0e2620;
  padding:5px 11px;border-radius:999px;background:rgba(46,125,184,.07);border:1px solid rgba(46,125,184,.2);
  transition:background .15s ease,color .15s ease,border-color .15s ease,transform .15s ease}
.cf-route:hover{background:#fff;border-color:#2E7DB8;color:#2E7DB8;transform:translateY(-1px)}
.cf-route.on{color:#fff;background:linear-gradient(120deg,#4E7A8A,#2E7DB8);border-color:transparent;
  box-shadow:0 8px 16px -9px rgba(46,125,184,.6)}
.cf-route[data-route="advice"].on{background:linear-gradient(120deg,#2E7DB8,#E85A28);
  animation:cfRoutePulse 2.4s ease-in-out infinite}
@keyframes cfRoutePulse{0%,100%{box-shadow:0 8px 16px -9px rgba(46,125,184,.6)}
  50%{box-shadow:0 8px 22px -6px rgba(232,90,40,.66)}}

/* 小伴建议条（真学情话术） */
.cf-advice{position:relative;z-index:3;display:none;margin-top:11px;font-size:12.5px;line-height:1.65;color:#10B981;
  background:rgba(46,125,184,.07);border:1px solid rgba(46,125,184,.18);border-radius:10px;padding:8px 12px}
.cf-advice .cf-mascot-ico{display:inline-block;width:22px;height:22px;margin-right:5px;vertical-align:-6px;
  border-radius:50%;object-fit:cover;background:#fff;box-shadow:0 2px 5px -2px rgba(46,125,184,.35)}

/* ---- 深色：夜航档 ---- */
html[data-theme="dark"] .cf-base{stroke:rgba(255,255,255,.16)}
html[data-theme="dark"] .cf-flowdash{stroke:var(--surface,#141220)}
html[data-theme="dark"] .cf-head{fill:#86B4D6}
html[data-theme="dark"] .cf-form{color:var(--ink-3,#8a93ad)}
html[data-theme="dark"] .cf-core-dot{background:#86B4D6;box-shadow:0 0 0 2px rgba(46,125,184,.22)}
html[data-theme="dark"] .cf-btn-main .cf-core-dot{background:#fff;box-shadow:0 0 0 2px rgba(255,255,255,.4)}
html[data-theme="dark"] .cf-routes-lab{color:var(--ink-2,#b9c1d6)}
html[data-theme="dark"] .cf-route{color:var(--ink-2,#b9c1d6);background:rgba(255,255,255,.05);border-color:rgba(255,255,255,.14)}
html[data-theme="dark"] .cf-route:hover{background:rgba(255,255,255,.1);color:#86B4D6;border-color:#2E7DB8}
html[data-theme="dark"] .cf-route.on{color:#fff}
html[data-theme="dark"] .cf-advice{color:#86B4D6;background:rgba(46,125,184,.13);border-color:rgba(46,125,184,.3)}