:root { color-scheme: light dark; }
  :root{
    --fg:#0f172a;
    --muted:#475569;
    --bgCard:rgba(255,255,255,0.92);
    --bd:rgba(15,23,42,0.14);
    --chip:#f1f5f9;
    --ctrlBg:#ffffff;
    --ctrlFg:var(--fg);
    --ctrlBd:var(--bd);
    --ctrlHover:rgba(15,23,42,0.06);
    --resultBg:rgba(15,23,42,0.04);
    --focus:#3b82f6;
  }
  @media (prefers-color-scheme: dark){
    :root{
      --fg:#e2e8f0;
      --muted:#94a3b8;
      --bgCard:rgba(15,23,42,0.55);
      --bd:rgba(148,163,184,0.22);
      --chip:#0b1220;
      --ctrlBg:#0b1220;
      --ctrlFg:#e2e8f0;
      --ctrlBd:rgba(148,163,184,0.25);
      --ctrlHover:rgba(148,163,184,0.10);
      --resultBg:rgba(148,163,184,0.10);
      --focus:#60a5fa;
    }
  }
  html, body { margin:0; padding:0; background:transparent; min-height: 100vh; }
  body { font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Arial, "Noto Sans", sans-serif; color:var(--fg); background:transparent; }
  .wrap { padding:16px; background:transparent; min-height: 100vh; }
  .card { background:var(--bgCard); border:1px solid var(--bd); border-radius:14px; padding:16px; max-width:980px; margin:0 auto; backdrop-filter: saturate(140%) blur(6px); }
  h1 { font-size:18px; margin:0 0 12px 0; }

  .tabs { display:flex; gap:8px; margin-bottom:10px; flex-wrap:wrap; }
  .tab { padding:8px 12px; border:1px solid var(--bd); background:var(--chip); border-radius:999px; cursor:pointer; user-select:none; transition: background .15s ease, border-color .15s ease; }
  .tab:hover { background:var(--ctrlHover); }
  .tab[aria-selected="true"] { outline:2px solid var(--bd); }
  .tab.external { background: linear-gradient(135deg, var(--chip) 0%, color-mix(in oklab, var(--focus) 15%, var(--chip)) 100%); }
  .tab.external:hover { background: linear-gradient(135deg, var(--ctrlHover) 0%, color-mix(in oklab, var(--focus) 25%, var(--ctrlHover)) 100%); }

  .row { display:flex; flex-wrap:wrap; gap:10px; margin:10px 0; }
  .field { display:flex; flex-direction:column; gap:6px; min-width:200px; flex:1; }
  label { font-weight:600; font-size:12px; color:var(--muted); }
  .muted { font-size:12px; color:var(--muted); }
  .inline { display:flex; align-items:center; gap:8px; }
  .twoCol { display:grid; grid-template-columns: repeat(auto-fit, minmax(220px,1fr)); gap:10px; }

  select, input[type="text"], input[type="number"], input[type="date"], input[type="month"], button{
    font:inherit; padding:10px 12px; border-radius:10px; border:1px solid var(--ctrlBd);
    background:var(--ctrlBg); color:var(--ctrlFg);
    transition: border-color .15s ease, background-color .15s ease, box-shadow .15s ease;
  }
  select:hover, input:hover, button:hover{ background:var(--ctrlHover); }
  select:focus, input:focus, button:focus{
    outline: none; border-color: var(--focus); box-shadow: 0 0 0 3px color-mix(in oklab, var(--focus) 35%, transparent);
  }
  button { cursor:pointer; }
  button:active { transform: translateY(1px); }

  .section { display:none; }
  .section.active { display:block; }

  .resultBox{ padding:10px 12px; border:1px dashed var(--bd); border-radius:10px; min-height:42px; background:var(--resultBg); }
  .err { color:#ef4444; font-size:12px; }
  ::selection{ background: color-mix(in oklab, var(--focus) 30%, transparent); }

  .time-inputs { display: flex; gap: 8px; align-items: center; }
  .time-input { width: 60px; text-align: center; }
  .time-separator { font-weight: bold; color: var(--muted); }

  /* Slider Styles */
  #calculatorSlider { animation: fadeIn 0.3s ease; }
  @keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }
  
  .slider-title { font-size: 24px; font-weight: 700; color: var(--focus); margin-bottom: 12px; }
  .slider-desc { font-size: 14px; line-height: 1.6; color: var(--fg); margin-bottom: 16px; }
  .slider-uses { font-size: 12px; color: var(--muted); margin-top: 12px; }
  .slider-uses strong { color: var(--fg); }
  
  #sliderDots { display: flex; flex-wrap: wrap; gap: 8px; }
  .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--bd); cursor: pointer; transition: background 0.2s; }
  .dot.active { background: var(--focus); }

/* Force the supplied dark calculator appearance on every device. */
:root{--fg:#e2e8f0;--muted:#94a3b8;--bgCard:rgba(15,23,42,0.55);--bd:rgba(148,163,184,0.22);--chip:#0b1220;--ctrlBg:#0b1220;--ctrlFg:#e2e8f0;--ctrlBd:rgba(148,163,184,0.25);--ctrlHover:rgba(148,163,184,0.10);--resultBg:rgba(148,163,184,0.10);--focus:#60a5fa}
.tab{color:var(--fg);text-decoration:none}
html,body{background:#0f0f0f}