/* ====== 04 和差倍问题计算器 · 直尺橙 + 墨蓝 ====== */
.tsk.sdm{
  --tsk-bg:#fbf6ee;
  --tsk-card:#ffffff;
  --tsk-card-2:#fdf9f1;
  --tsk-ink:#2a3145;
  --tsk-sub:#5c6478;
  --tsk-faint:#949aab;
  --tsk-line:#e9e0ce;
  --tsk-line-2:#f3ecdd;
  --tsk-brand:#d9772e;
  --tsk-brand-2:#b4571b;
  --tsk-brand-soft:#fbeedf;
  --tsk-brand-ink:#a9521a;
  --tsk-ink-blue:#3c4f8a;
  --tsk-blue-soft:#e9edf7;
  --tsk-shadow-sm:0 1px 2px rgba(42,49,69,.05),0 8px 18px rgba(42,49,69,.06);
  --tsk-shadow:0 2px 8px rgba(42,49,69,.08),0 22px 48px rgba(42,49,69,.10);
  background:
    radial-gradient(660px 300px at 100% -8%, rgba(60,79,138,.10), transparent 64%),
    repeating-linear-gradient(0deg, transparent 0 39px, rgba(217,119,46,.05) 39px 40px),
    var(--tsk-bg);
}
:root[data-theme="dark"] .tsk.sdm{
  --tsk-bg:#14131a;
  --tsk-card:#1d1c26;
  --tsk-card-2:#25242f;
  --tsk-ink:#eceaf5;
  --tsk-sub:#b4b1c4;
  --tsk-faint:#858295;
  --tsk-line:#373444;
  --tsk-line-2:#2b2937;
  --tsk-brand:#f0a061;
  --tsk-brand-2:#ffc08a;
  --tsk-brand-soft:rgba(240,160,97,.14);
  --tsk-brand-ink:#ffc08a;
  --tsk-ink-blue:#93a4de;
  --tsk-blue-soft:rgba(147,164,222,.13);
}

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

/* ---- 工作台 ---- */
.sdm-workbench{background:var(--tsk-card);border:1px solid var(--tsk-line);border-radius:15px;
  box-shadow:var(--tsk-shadow);padding:17px 19px 14px;position:relative;overflow:hidden}
.sdm-workbench::before{content:"";position:absolute;left:0;right:0;top:0;height:5px;
  background:repeating-linear-gradient(90deg,var(--tsk-brand) 0 10px,var(--tsk-ink-blue) 10px 20px)}
.sdm-wb-hd{display:flex;align-items:center;gap:10px;margin-top:4px}
.sdm-wb-icon{width:35px;height:35px;flex:none;display:grid;place-items:center;border-radius:9px;
  background:var(--tsk-brand-soft);border:1px solid rgba(217,119,46,.2);font-size:16px}
.sdm-wb-hd b{display:block;font-size:14.5px;font-weight:800}
.sdm-wb-hd small{display:block;font-size:11.5px;color:var(--tsk-faint)}

.sdm-tabs{display:flex;gap:5px;margin-top:12px;padding:4px;border-radius:10px;background:var(--tsk-card-2);
  border:1px solid var(--tsk-line-2)}
.sdm-tab{flex:1;border:0;background:transparent;border-radius:7px;color:var(--tsk-sub);cursor:pointer;
  font:700 11.5px/1.4 var(--tsk-font);padding:8px 4px;transition:.16s;white-space:nowrap}
.sdm-tab:hover{color:var(--tsk-brand-ink)}
.sdm-tab.on{background:var(--tsk-ink-blue);color:#fff;box-shadow:0 4px 10px rgba(60,79,138,.24)}
:root[data-theme="dark"] .sdm-tab.on{color:#14131a}

.sdm-panel{padding-top:12px}
.sdm-row2{display:grid;grid-template-columns:1fr 1fr;gap:9px}
.sdm-field label{display:block;margin-bottom:4px;font-size:11.5px;font-weight:800;color:var(--tsk-sub)}
.sdm-field input{width:100%;height:39px;border:1.5px solid var(--tsk-line);border-radius:9px;
  background:var(--tsk-card-2);color:var(--tsk-ink);font:800 14.5px/39px var(--tsk-num);padding:0 11px;outline:none;transition:.15s}
.sdm-field input:focus{border-color:var(--tsk-brand);box-shadow:0 0 0 3px var(--tsk-brand-soft)}
.sdm-field.bad input{border-color:var(--tsk-bad);background:var(--tsk-bad-soft)}
.sdm-note{margin:10px 0 0;padding:7px 10px;border-radius:7px;background:var(--tsk-card-2);
  border-left:2px solid var(--tsk-brand);font-size:10.8px;line-height:1.7;color:var(--tsk-faint)}
.sdm-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}
.sdm-err.show{display:block}
.sdm-acts{display:flex;gap:7px;margin-top:13px}
.sdm-acts .tsk-btn{padding:9px 13px;font-size:12.5px}
.sdm-acts .tsk-btn-main{flex:1;border:0;background:linear-gradient(135deg,var(--tsk-brand),var(--tsk-brand-2))}
.sdm-wb-foot{margin:9px 0 0;font-size:10.5px;line-height:1.65;color:var(--tsk-faint)}

/* ---- 结果 ---- */
.sdm-result{margin:6px 0 28px;background:var(--tsk-card);border:1px solid var(--tsk-line);
  border-radius:18px;box-shadow:var(--tsk-shadow);padding:22px 24px 20px}
.sdm-res-hd{display:flex;justify-content:space-between;align-items:center;gap:12px;margin-bottom:13px}
.sdm-res-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(160px,1fr));gap:10px}
.sdm-res-card{background:var(--tsk-card-2);border:1px solid var(--tsk-line-2);border-radius:12px;padding:15px 17px 13px}
.sdm-res-card b{display:block;font:800 27px/1.12 var(--tsk-num);color:var(--tsk-ink);font-variant-numeric:tabular-nums;word-break:break-all}
.sdm-res-card span{display:block;margin-top:4px;font-size:11.5px;font-weight:800;color:var(--tsk-faint)}
.sdm-res-card i{display:block;margin-top:2px;font-style:normal;font-size:10.5px;color:var(--tsk-sub)}
.sdm-res-card.sdm-main-card{background:var(--tsk-blue-soft);border-color:rgba(60,79,138,.22)}
.sdm-res-card.sdm-main-card b{color:var(--tsk-ink-blue)}
.sdm-alert{margin-top:12px;padding:10px 13px;border-radius:9px;background:var(--tsk-brand-soft);
  border-left:3px solid var(--tsk-brand);font-size:12.5px;line-height:1.8;color:var(--tsk-sub)}
.sdm-alert.is-bad{background:var(--tsk-bad-soft);border-left-color:var(--tsk-bad)}

/* ---- 线段图 ---- */
.sdm-diagram{margin-top:17px;padding:14px 16px 8px;border:1px dashed var(--tsk-line);border-radius:12px;
  background:var(--tsk-card-2)}
.sdm-diagram-hd{display:flex;align-items:center;justify-content:space-between;gap:10px;margin-bottom:4px}
.sdm-diagram-hd h3{margin:0;color:var(--tsk-ink-blue)}
.sdm-diagram-hd span{font-size:11px;color:var(--tsk-faint)}
.sdm-diagram svg{display:block;width:100%;height:auto}
.sdm-steps-wrap{margin-top:16px;padding-top:14px;border-top:1px dashed var(--tsk-line)}
.sdm-steps{margin:9px 0 0;padding:0;list-style:none;counter-reset:sdmstep;display:grid;gap:6px}
.sdm-steps li{counter-increment:sdmstep;position:relative;padding:8px 12px 8px 38px;border-radius:8px;
  background:var(--tsk-card-2);border:1px solid var(--tsk-line-2);font-size:12.8px;line-height:1.78;color:var(--tsk-sub)}
.sdm-steps li::before{content:counter(sdmstep);position:absolute;left:10px;top:8px;width:19px;height:19px;
  border-radius:5px;background:var(--tsk-brand);color:#fff;font:800 10.5px/19px var(--tsk-num);text-align:center}
.sdm-steps li b{color:var(--tsk-ink)}
.sdm-sub{margin-left:auto;font-size:11.5px;font-weight:700;color:var(--tsk-faint)}

/* ---- 公式卡 ---- */
.sdm-fmls{display:grid;grid-template-columns:repeat(auto-fit,minmax(258px,1fr));gap:11px}
.sdm-fml{background:var(--tsk-card);border:1px solid var(--tsk-line);border-radius:12px;
  box-shadow:var(--tsk-shadow-sm);padding:16px 17px;border-top:3px solid var(--tsk-ink-blue)}
.sdm-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)}
.sdm-fml p{margin:8px 0;font-size:12.5px;line-height:1.75;color:var(--tsk-sub)}
.sdm-fml code{display:block;padding:8px 10px;border-radius:7px;background:var(--tsk-card-2);
  color:var(--tsk-ink-blue);font:800 11.5px/1.7 var(--tsk-num);word-break:break-all}

/* ---- 变式 ---- */
.sdm-var-toolbar{display:flex;flex-wrap:wrap;align-items:center;gap:8px;margin-bottom:11px}
.sdm-var-tip{font-size:11.5px;color:var(--tsk-faint)}
.sdm-variants{display:grid;grid-template-columns:repeat(auto-fit,minmax(300px,1fr));gap:9px}
.sdm-variants .tsk-empty{grid-column:1/-1;background:var(--tsk-card);border:1px dashed var(--tsk-line);border-radius:10px}
.sdm-var-item{background:var(--tsk-card);border:1px solid var(--tsk-line);border-left:3px solid var(--tsk-brand);
  border-radius:10px;padding:12px 14px;box-shadow:var(--tsk-shadow-sm)}
.sdm-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)}
.sdm-var-item .q{font-size:12.8px;line-height:1.8;color:var(--tsk-sub)}
.sdm-var-item .q b{color:var(--tsk-ink)}
.sdm-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}
.sdm-var-item .ans.is-hidden{display:none}
.sdm-var-item .ans b{color:var(--tsk-brand-ink)}

/* ---- 自测 ---- */
.sdm-quiz{background:var(--tsk-card);border:1px solid var(--tsk-line);border-left:4px solid var(--tsk-ink-blue);
  border-radius:12px;box-shadow:var(--tsk-shadow-sm);padding:17px 19px}
.sdm-question{margin:0 0 10px;font-size:14px;line-height:1.85;font-weight:700;color:var(--tsk-ink)}
.sdm-quiz-row{display:flex;flex-wrap:wrap;gap:8px}
.sdm-quiz-row input{width:150px;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}
.sdm-quiz-row input:focus{border-color:var(--tsk-brand);box-shadow:0 0 0 3px var(--tsk-brand-soft)}
.sdm-quiz-fb{margin:8px 0 0;min-height:19px;font-size:12.5px;font-weight:800}
.sdm-quiz-fb.ok{color:var(--tsk-ink-blue)}
.sdm-quiz-fb.no{color:var(--tsk-brand-2)}

@media (max-width:900px){
  .sdm-hero{grid-template-columns:1fr;gap:22px}
}
@media (max-width:600px){
  .sdm-res-grid{grid-template-columns:1fr 1fr}
  .sdm-acts{flex-wrap:wrap}
  .sdm-acts .tsk-btn-main{flex:1 0 100%}
  .sdm-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
   * ========================================================== */
.sdm .tsk-btn:focus-visible,
.sdm .sdm-tab:focus-visible,
.sdm .sdm-seg button:focus-visible{
    outline:2px solid var(--tsk-brand);
    outline-offset:2px;
}
.sdm input[type="number"]::-webkit-outer-spin-button,
.sdm input[type="number"]::-webkit-inner-spin-button{
    -webkit-appearance:none;
    margin:0;
}
.sdm input[type="number"]{
    -moz-appearance:textfield;
    appearance:textfield;
}
.sdm input::placeholder,
.sdm textarea::placeholder{
    color:var(--tsk-faint);
    opacity:1;
}
.sdm ::selection{
    background:var(--tsk-brand-soft);
    color:var(--tsk-brand-ink);
}
.sdm .sdm-res-card b,
.sdm .sdm-main-card b{
    font-variant-numeric:tabular-nums lining-nums;
    letter-spacing:-.01em;
    line-height:1.15;
}
.sdm .sdm-res-card b{
    overflow-wrap:anywhere;
}
.sdm .sdm-var-item .q,
.sdm .sdm-question,
.sdm .sdm-steps li{
    overflow-wrap:break-word;
    word-break:normal;
}
.sdm .sdm-table-wrap{
    scrollbar-width:thin;
    scrollbar-color:var(--tsk-line) transparent;
}
.sdm .sdm-table-wrap::-webkit-scrollbar{
    height:8px;
}
.sdm .sdm-table-wrap::-webkit-scrollbar-thumb{
    background:var(--tsk-line);
    border-radius:99px;
}
.sdm .sdm-table-wrap::-webkit-scrollbar-track{
    background:transparent;
}
.sdm .sdm-var-toolbar .tsk-btn,
.sdm .sdm-acts .tsk-btn,
.sdm .sdm-quiz-row .tsk-btn{
    touch-action:manipulation;
}
.sdm .sdm-var-item{
    transition:border-color .15s,box-shadow .15s;
}
.sdm .sdm-var-item:hover{
    border-color:var(--tsk-brand);
    box-shadow:var(--tsk-shadow-sm);
}
.sdm .sdm-panel:not(.on){
    display:none;
}
.sdm .sdm-result[hidden]{
    display:none;
}
.sdm .sdm-result{
    animation:sdm-rise .28s ease both;
}
@keyframes sdm-rise{
    from{opacity:0;transform:translateY(8px)}
    to{opacity:1;transform:none}
}
.sdm .sdm-alert b{
    font-weight:800;
}
.sdm .sdm-err.show{
    animation:sdm-shake .22s ease;
}
@keyframes sdm-shake{
    0%,100%{transform:translateX(0)}
    25%{transform:translateX(-3px)}
    75%{transform:translateX(3px)}
}
.sdm .tsk-empty{
    padding:18px 16px;
    text-align:center;
    color:var(--tsk-faint);
    font-size:12.5px;
    line-height:1.8;
}
.sdm .sdm-quiz-row input:disabled,
.sdm .sdm-acts .tsk-btn:disabled{
    opacity:.55;
    cursor:not-allowed;
}
.sdm .sdm-res-grid > .sdm-res-card:last-child:nth-child(odd){
    grid-column:span 2;
}
@media (max-width:420px){
    .sdm .sdm-res-grid{
        grid-template-columns:1fr;
    }
    .sdm .sdm-res-grid > .sdm-res-card:last-child:nth-child(odd){
        grid-column:auto;
    }
    .sdm .sdm-row2,
    .sdm .sdm-row3{
        grid-template-columns:1fr;
    }
}
@media (prefers-reduced-motion:reduce){
    .sdm *,
    .sdm *::before,
    .sdm *::after{
        animation-duration:.001ms!important;
        animation-iteration-count:1!important;
        transition-duration:.001ms!important;
        scroll-behavior:auto!important;
    }
}
@media print{
    .sdm{
        background:#fff!important;
        color:#111!important;
    }
    .sdm .tsk-crumb-bar,
    .sdm .sdm-acts,
    .sdm .sdm-var-toolbar,
    .sdm .sdm-quiz,
    .sdm .sdm-tabs{
        display:none!important;
    }
    .sdm .sdm-result{
        box-shadow:none!important;
        border:1px solid #ddd!important;
        animation:none!important;
    }
    .sdm .sdm-res-grid{
        grid-template-columns:repeat(2,minmax(0,1fr))!important;
    }
    .sdm .sdm-var-item{
        break-inside:avoid;
    }
    .sdm .sdm-table{
        font-size:11px!important;
    }
}