/* ====== 06 火车过桥计算器 · 铁轨灰 + 信号黄 ====== */
.tsk.tbc{
  --tsk-bg:#f3f4f2;
  --tsk-card:#ffffff;
  --tsk-card-2:#f7f8f5;
  --tsk-ink:#23282b;
  --tsk-sub:#5b6468;
  --tsk-faint:#8f999d;
  --tsk-line:#dfe3df;
  --tsk-line-2:#edf0ec;
  --tsk-brand:#b8860b;
  --tsk-brand-2:#8a6507;
  --tsk-brand-soft:#faf1d6;
  --tsk-brand-ink:#7c5a06;
  --tsk-steel:#3d4a52;
  --tsk-steel-soft:#e8ecef;
  --tsk-signal:#e0a100;
  --tsk-shadow-sm:0 1px 2px rgba(35,40,43,.06),0 8px 18px rgba(35,40,43,.07);
  --tsk-shadow:0 2px 8px rgba(35,40,43,.09),0 22px 48px rgba(35,40,43,.11);
  background:
    radial-gradient(600px 280px at 100% -10%, rgba(224,161,0,.10), transparent 64%),
    repeating-linear-gradient(90deg, transparent 0 71px, rgba(61,74,82,.045) 71px 72px),
    var(--tsk-bg);
}
:root[data-theme="dark"] .tsk.tbc{
  --tsk-bg:#101315;
  --tsk-card:#181d20;
  --tsk-card-2:#1f2529;
  --tsk-ink:#e9edef;
  --tsk-sub:#aab4b9;
  --tsk-faint:#7d898f;
  --tsk-line:#2b3338;
  --tsk-line-2:#232b30;
  --tsk-brand:#f0c14b;
  --tsk-brand-2:#ffd66e;
  --tsk-brand-soft:rgba(240,193,75,.14);
  --tsk-brand-ink:#ffd66e;
  --tsk-steel:#9fb3bf;
  --tsk-steel-soft:rgba(159,179,191,.12);
  --tsk-signal:#ffc933;
}

/* ---- 首屏等高栅格 ---- */
.tbc-hero{display:grid;grid-template-columns:minmax(0,1fr) 394px;gap:30px;padding:30px 0 24px;align-items:stretch}
.tbc-hero-l{display:flex;flex-direction:column}
.tbc-hero-l>.tsk-hs{flex:1 1 auto}
@media (max-width:900px){.tbc-hero{grid-template-columns:1fr}}
.tbc-hero-l .tsk-h1 b{color:var(--tsk-signal)}

/* ---- 调度台 ---- */
.tbc-dispatch{position:relative;background:var(--tsk-card);border:1px solid var(--tsk-line);
  border-radius:14px;box-shadow:var(--tsk-shadow);padding:17px 19px 14px;overflow:hidden}
.tbc-dispatch::before{content:"";position:absolute;left:0;right:0;top:0;height:5px;
  background:repeating-linear-gradient(135deg,var(--tsk-steel) 0 9px,var(--tsk-signal) 9px 18px)}
.tbc-dispatch-hd{display:flex;align-items:center;gap:10px;margin-top:3px}
.tbc-signal{width:12px;height:12px;flex:none;border-radius:50%;background:var(--tsk-signal);
  box-shadow:0 0 0 3px rgba(224,161,0,.18),0 0 12px rgba(224,161,0,.55)}
.tbc-dispatch-hd b{display:block;font-size:14.5px;font-weight:800}
.tbc-dispatch-hd small{display:block;font-size:11.5px;color:var(--tsk-faint)}
.tbc-mode-badge{margin-left:auto;font:800 10px/1 var(--tsk-num);letter-spacing:.16em;
  color:var(--tsk-steel);border:1px solid var(--tsk-line);border-radius:6px;padding:6px 7px}

.tbc-tabs{display:flex;gap:5px;margin-top:12px;padding:4px;border-radius:9px;background:var(--tsk-card-2);
  border:1px solid var(--tsk-line-2)}
.tbc-tab{flex:1;border:0;background:transparent;border-radius:6px;color:var(--tsk-sub);cursor:pointer;
  font:700 11.2px/1.4 var(--tsk-font);padding:8px 3px;transition:.16s;white-space:nowrap}
.tbc-tab:hover{color:var(--tsk-brand-ink)}
.tbc-tab.on{background:var(--tsk-steel);color:#fff;box-shadow:0 4px 10px rgba(61,74,82,.24)}
:root[data-theme="dark"] .tbc-tab.on{color:#101315}

.tbc-panel{padding-top:13px}
.tbc-row2{display:grid;grid-template-columns:1fr 1fr;gap:9px}
.tbc-row3{display:grid;grid-template-columns:1fr 1fr 1fr;gap:8px}
.tbc-field label{display:block;margin-bottom:4px;font-size:11px;font-weight:800;color:var(--tsk-sub);line-height:1.5}
.tbc-field input,.tbc-field select{width:100%;height:39px;border:1.5px solid var(--tsk-line);border-radius:8px;
  background:var(--tsk-card-2);color:var(--tsk-ink);font:800 13.5px/39px var(--tsk-num);padding:0 10px;outline:none;transition:.15s}
.tbc-field select{font-family:var(--tsk-font);font-weight:700}
.tbc-field input:focus,.tbc-field select:focus{border-color:var(--tsk-brand);box-shadow:0 0 0 3px var(--tsk-brand-soft)}
.tbc-field.bad input,.tbc-field.bad select{border-color:var(--tsk-bad);background:var(--tsk-bad-soft)}
.tbc-note{margin:10px 0 0;padding:7px 10px;border-radius:6px;background:var(--tsk-card-2);
  border-left:3px solid var(--tsk-signal);font-size:10.8px;line-height:1.7;color:var(--tsk-faint)}
.tbc-err{display:none;margin:9px 0 0;padding:8px 11px;border-radius:8px;background:var(--tsk-bad-soft);
  color:var(--tsk-bad);font-size:12px;font-weight:700;line-height:1.65}
.tbc-err.show{display:block}
.tbc-acts{display:flex;gap:7px;margin-top:13px}
.tbc-acts .tsk-btn{padding:9px 13px;font-size:12.5px}
.tbc-acts .tsk-btn-main{flex:1;border:0;background:linear-gradient(135deg,var(--tsk-steel),#2b353b)}
.tbc-dispatch-foot{margin:10px 0 0;font-size:10.5px;line-height:1.65;color:var(--tsk-faint)}

/* ---- 结果 ---- */
.tbc-result{margin:6px 0 28px;background:var(--tsk-card);border:1px solid var(--tsk-line);
  border-radius:16px;box-shadow:var(--tsk-shadow);padding:22px 24px 20px}
.tbc-res-hd{display:flex;justify-content:space-between;align-items:center;gap:12px;margin-bottom:13px}
.tbc-res-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(158px,1fr));gap:10px}
.tbc-res-card{background:var(--tsk-card-2);border:1px solid var(--tsk-line-2);border-radius:11px;padding:15px 17px 13px}
.tbc-res-card b{display:block;font:800 26px/1.12 var(--tsk-num);color:var(--tsk-ink);font-variant-numeric:tabular-nums;word-break:break-all}
.tbc-res-card span{display:block;margin-top:4px;font-size:11.5px;font-weight:800;color:var(--tsk-faint)}
.tbc-res-card i{display:block;margin-top:2px;font-style:normal;font-size:10.5px;color:var(--tsk-sub)}
.tbc-res-card.tbc-main-card{background:var(--tsk-brand-soft);border-color:rgba(184,134,11,.25)}
.tbc-res-card.tbc-main-card b{color:var(--tsk-signal)}
.tbc-alert{margin-top:12px;padding:10px 13px;border-radius:8px;background:var(--tsk-steel-soft);
  border-left:3px solid var(--tsk-steel);font-size:12.5px;line-height:1.8;color:var(--tsk-sub)}
.tbc-alert.is-bad{background:var(--tsk-bad-soft);border-left-color:var(--tsk-bad)}

/* ---- 明细 ---- */
.tbc-table-wrap{margin-top:15px;overflow-x:auto;border-radius:9px;border:1px solid var(--tsk-line)}
.tbc-table{width:100%;min-width:520px;border-collapse:collapse;background:var(--tsk-card)}
.tbc-table th,.tbc-table td{padding:9px 13px;font-size:12.3px;line-height:1.7;text-align:left;border-bottom:1px solid var(--tsk-line-2)}
.tbc-table thead th{background:var(--tsk-steel);color:#fff;font-size:11px;font-weight:800;letter-spacing:.04em}
.tbc-table tbody tr:last-child td{border-bottom:0}
.tbc-table tbody tr:hover td{background:var(--tsk-card-2)}
.tbc-table td:first-child{font-weight:800;color:var(--tsk-ink)}
.tbc-table td:nth-child(2){font:800 12.5px/1.7 var(--tsk-num);color:var(--tsk-brand-ink)}

/* ---- 步骤 ---- */
.tbc-steps-wrap{margin-top:16px;padding-top:14px;border-top:1px dashed var(--tsk-line)}
.tbc-steps{margin:9px 0 0;padding:0;list-style:none;counter-reset:tbcstep;display:grid;gap:6px}
.tbc-steps li{counter-increment:tbcstep;position:relative;padding:8px 12px 8px 38px;border-radius:7px;
  background:var(--tsk-card-2);border:1px solid var(--tsk-line-2);font-size:12.8px;line-height:1.78;color:var(--tsk-sub)}
.tbc-steps li::before{content:counter(tbcstep);position:absolute;left:10px;top:8px;width:19px;height:19px;
  border-radius:4px;background:var(--tsk-steel);color:#fff;font:800 10.5px/19px var(--tsk-num);text-align:center}
.tbc-steps li b{color:var(--tsk-ink)}
.tbc-sub{margin-left:auto;font-size:11.5px;font-weight:700;color:var(--tsk-faint)}

/* ---- 公式卡 ---- */
.tbc-fmls{display:grid;grid-template-columns:repeat(auto-fit,minmax(250px,1fr));gap:11px}
.tbc-fml{background:var(--tsk-card);border:1px solid var(--tsk-line);border-radius:11px;
  box-shadow:var(--tsk-shadow-sm);padding:15px 16px;border-top:3px solid var(--tsk-signal)}
.tbc-tag{display:inline-block;padding:2px 9px;border-radius:99px;background:var(--tsk-brand-soft);
  color:var(--tsk-brand-ink);font:800 11px/1.7 var(--tsk-num)}
.tbc-fml code{display:block;margin:8px 0;padding:8px 10px;border-radius:6px;background:var(--tsk-card-2);
  color:var(--tsk-steel);font:800 11.5px/1.7 var(--tsk-num);word-break:break-all}
.tbc-fml p{margin:0;font-size:12.3px;line-height:1.75;color:var(--tsk-sub)}
.tbc-diagram{display:flex;align-items:center;gap:7px;margin-top:9px;padding-top:8px;border-top:1px dashed var(--tsk-line-2)}
.tbc-train{font-size:17px;line-height:1}
.tbc-diagram i{flex:1;height:4px;border-radius:99px;background:repeating-linear-gradient(90deg,var(--tsk-line) 0 7px,var(--tsk-card-2) 7px 12px)}
.tbc-bridge{font-size:10.5px;font-weight:800;color:var(--tsk-faint)}

/* ---- 变式 ---- */
.tbc-var-toolbar{display:flex;flex-wrap:wrap;align-items:center;gap:8px;margin-bottom:11px}
.tbc-var-tip{font-size:11.5px;color:var(--tsk-faint)}
.tbc-variants{display:grid;grid-template-columns:repeat(auto-fit,minmax(300px,1fr));gap:9px}
.tbc-variants .tsk-empty{grid-column:1/-1;background:var(--tsk-card);border:1px dashed var(--tsk-line);border-radius:9px}
.tbc-var-item{background:var(--tsk-card);border:1px solid var(--tsk-line);border-left:3px solid var(--tsk-signal);
  border-radius:9px;padding:12px 14px;box-shadow:var(--tsk-shadow-sm)}
.tbc-var-item .no{display:inline-block;margin-right:6px;padding:1px 7px;border-radius:99px;
  background:var(--tsk-brand-soft);color:var(--tsk-brand-ink);font:800 10.5px/1.8 var(--tsk-num)}
.tbc-var-item .q{font-size:12.8px;line-height:1.8;color:var(--tsk-sub)}
.tbc-var-item .q b{color:var(--tsk-ink)}
.tbc-var-item .ans{margin-top:6px;padding-top:6px;border-top:1px dashed var(--tsk-line-2);
  font-size:12px;line-height:1.7;color:var(--tsk-brand-ink);font-weight:700}
.tbc-var-item .ans.is-hidden{display:none}
.tbc-var-item .ans b{color:var(--tsk-brand-ink)}

/* ---- 自测 ---- */
.tbc-quiz{background:var(--tsk-card);border:1px solid var(--tsk-line);border-left:4px solid var(--tsk-signal);
  border-radius:11px;box-shadow:var(--tsk-shadow-sm);padding:17px 19px}
.tbc-question{margin:0 0 10px;font-size:14px;line-height:1.85;font-weight:700;color:var(--tsk-ink)}
.tbc-quiz-row{display:flex;flex-wrap:wrap;gap:8px}
.tbc-quiz-row input{width:170px;height:39px;padding:0 11px;border:1.5px solid var(--tsk-line);border-radius:8px;
  background:var(--tsk-card-2);color:var(--tsk-ink);font:800 14px/39px var(--tsk-num);outline:none}
.tbc-quiz-row input:focus{border-color:var(--tsk-brand);box-shadow:0 0 0 3px var(--tsk-brand-soft)}
.tbc-quiz-fb{margin:8px 0 0;min-height:19px;font-size:12.5px;font-weight:800}
.tbc-quiz-fb.ok{color:var(--tsk-brand-ink)}
.tbc-quiz-fb.no{color:var(--tsk-bad)}

@media (max-width:900px){
  .tbc-hero{grid-template-columns:1fr;gap:22px}
}
@media (max-width:600px){
  .tbc-row3{grid-template-columns:1fr 1fr}
  .tbc-res-grid{grid-template-columns:1fr 1fr}
  .tbc-acts{flex-wrap:wrap}
  .tbc-acts .tsk-btn-main{flex:1 0 100%}
  .tbc-quiz-row input{flex:1 0 100%;width:100%}
}

/* ==========================================================
   *  细节打磨：键盘可达性、长数字换行、打印与动效降级
   *  说明：以下规则都限定在 .tsk 工具作用域内，不影响站内其它页面
   * ========================================================== */
.tbc .tsk-btn:focus-visible,
.tbc .tbc-tab:focus-visible,
.tbc .tbc-seg button:focus-visible{
    outline:2px solid var(--tsk-brand);
    outline-offset:2px;
}
.tbc input[type="number"]::-webkit-outer-spin-button,
.tbc input[type="number"]::-webkit-inner-spin-button{
    -webkit-appearance:none;
    margin:0;
}
.tbc input[type="number"]{
    -moz-appearance:textfield;
    appearance:textfield;
}
.tbc input::placeholder,
.tbc textarea::placeholder{
    color:var(--tsk-faint);
    opacity:1;
}
.tbc ::selection{
    background:var(--tsk-brand-soft);
    color:var(--tsk-brand-ink);
}
.tbc .tbc-res-card b,
.tbc .tbc-main-card b{
    font-variant-numeric:tabular-nums lining-nums;
    letter-spacing:-.01em;
    line-height:1.15;
}
.tbc .tbc-res-card b{
    overflow-wrap:anywhere;
}
.tbc .tbc-var-item .q,
.tbc .tbc-question,
.tbc .tbc-steps li{
    overflow-wrap:break-word;
    word-break:normal;
}
.tbc .tbc-table-wrap{
    scrollbar-width:thin;
    scrollbar-color:var(--tsk-line) transparent;
}
.tbc .tbc-table-wrap::-webkit-scrollbar{
    height:8px;
}
.tbc .tbc-table-wrap::-webkit-scrollbar-thumb{
    background:var(--tsk-line);
    border-radius:99px;
}
.tbc .tbc-table-wrap::-webkit-scrollbar-track{
    background:transparent;
}
.tbc .tbc-var-toolbar .tsk-btn,
.tbc .tbc-acts .tsk-btn,
.tbc .tbc-quiz-row .tsk-btn{
    touch-action:manipulation;
}
.tbc .tbc-var-item{
    transition:border-color .15s,box-shadow .15s;
}
.tbc .tbc-var-item:hover{
    border-color:var(--tsk-brand);
    box-shadow:var(--tsk-shadow-sm);
}
.tbc .tbc-panel:not(.on){
    display:none;
}
.tbc .tbc-result[hidden]{
    display:none;
}
.tbc .tbc-result{
    animation:tbc-rise .28s ease both;
}
@keyframes tbc-rise{
    from{opacity:0;transform:translateY(8px)}
    to{opacity:1;transform:none}
}
.tbc .tbc-alert b{
    font-weight:800;
}
.tbc .tbc-err.show{
    animation:tbc-shake .22s ease;
}
@keyframes tbc-shake{
    0%,100%{transform:translateX(0)}
    25%{transform:translateX(-3px)}
    75%{transform:translateX(3px)}
}
.tbc .tsk-empty{
    padding:18px 16px;
    text-align:center;
    color:var(--tsk-faint);
    font-size:12.5px;
    line-height:1.8;
}
.tbc .tbc-quiz-row input:disabled,
.tbc .tbc-acts .tsk-btn:disabled{
    opacity:.55;
    cursor:not-allowed;
}
.tbc .tbc-res-grid > .tbc-res-card:last-child:nth-child(odd){
    grid-column:span 2;
}
@media (max-width:420px){
    .tbc .tbc-res-grid{
        grid-template-columns:1fr;
    }
    .tbc .tbc-res-grid > .tbc-res-card:last-child:nth-child(odd){
        grid-column:auto;
    }
    .tbc .tbc-row2,
    .tbc .tbc-row3{
        grid-template-columns:1fr;
    }
}
@media (prefers-reduced-motion:reduce){
    .tbc *,
    .tbc *::before,
    .tbc *::after{
        animation-duration:.001ms!important;
        animation-iteration-count:1!important;
        transition-duration:.001ms!important;
        scroll-behavior:auto!important;
    }
}
@media print{
    .tbc{
        background:#fff!important;
        color:#111!important;
    }
    .tbc .tsk-crumb-bar,
    .tbc .tbc-acts,
    .tbc .tbc-var-toolbar,
    .tbc .tbc-quiz,
    .tbc .tbc-tabs{
        display:none!important;
    }
    .tbc .tbc-result{
        box-shadow:none!important;
        border:1px solid #ddd!important;
        animation:none!important;
    }
    .tbc .tbc-res-grid{
        grid-template-columns:repeat(2,minmax(0,1fr))!important;
    }
    .tbc .tbc-var-item{
        break-inside:avoid;
    }
    .tbc .tbc-table{
        font-size:11px!important;
    }
}