:root{
        color-scheme: light;
        --bg:#ffffff; --surface:#ffffff; --surface2:#f8fafc; --ink:#1e293b; --muted:#5b6b82;
        --line:#e2e8f0; --accent:#0f766e; --accent2:#0284c7; --accent-ink:#ffffff; --accent-soft:#ccfbf1;
        --amber:#b45309; --amber-soft:#fef3c7; --danger:#be123c; --danger-soft:#ffe4e6;
        --ok:#0f766e; --code-bg:#f1f5f9; --code-ink:#1e293b;
        --shadow:0 2px 10px rgba(30,41,59,.06),0 12px 32px rgba(30,41,59,.07);
        --shadow-lg:0 8px 20px rgba(15,118,110,.14),0 20px 44px rgba(2,132,199,.14);
        --radius:18px; --radius-sm:12px;
      }
      
      /* ---------- keyframes (transform/opacity only) ---------- */
      @keyframes fadeUp{from{opacity:0;transform:translateY(18px)}to{opacity:1;transform:translateY(0)}}
      @keyframes fadeIn{from{opacity:0}to{opacity:1}}
      @keyframes popIn{0%{opacity:0;transform:scale(.96) translateY(6px)}100%{opacity:1;transform:scale(1) translateY(0)}}
      @keyframes resultPop{0%{opacity:.4;transform:scale(.985)}55%{transform:scale(1.012)}100%{opacity:1;transform:scale(1)}}
      @keyframes floaty{0%,100%{transform:translate3d(0,0,0)}50%{transform:translate3d(0,-16px,0)}}
      @keyframes floaty2{0%,100%{transform:translate3d(0,0,0) rotate(0deg)}50%{transform:translate3d(-12px,12px,0) rotate(8deg)}}
      @keyframes heroIn{from{opacity:0;transform:translateY(14px) scale(.995)}to{opacity:1;transform:translateY(0) scale(1)}}
      @keyframes pulseDot{0%,100%{transform:scale(1);opacity:1}50%{transform:scale(1.35);opacity:.6}}

      *{box-sizing:border-box}
      html{scroll-behavior:smooth;color-scheme:light;background:#ffffff}
      body{margin:0;background-color:#ffffff;color:var(--ink);line-height:1.55;-webkit-font-smoothing:antialiased;overflow-x:hidden;
        font-family:"Plus Jakarta Sans",ui-sans-serif,system-ui,-apple-system,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
        background:
          radial-gradient(720px 380px at 8% -4%,rgba(254,243,199,.55),transparent 62%),
          radial-gradient(860px 460px at 94% 2%,rgba(186,230,253,.5),transparent 62%),
          radial-gradient(760px 420px at 50% 108%,rgba(187,247,208,.45),transparent 60%),
          var(--bg)}
      
      .wrap{max-width:1280px;margin:0 auto;padding:0 clamp(16px,4vw,36px) 72px;width:100%}
      h1,h2,h3{font-family:"Plus Jakarta Sans",ui-sans-serif,system-ui,sans-serif;font-weight:800;line-height:1.12;margin:0;letter-spacing:-.02em}
      a{color:var(--accent)}
      button{font:inherit;cursor:pointer}
      input,select,textarea{font:inherit;color:var(--ink)}
      .num{font-variant-numeric:tabular-nums}
      :focus-visible{outline:3px solid rgba(2,132,199,.45);outline-offset:2px;border-radius:6px}
      #app.page-enter{animation:fadeUp .45s cubic-bezier(.22,.8,.32,1) both}
      @keyframes revealSafety{to{opacity:1;transform:translateY(0)}}
      .reveal{opacity:0;transform:translateY(16px);animation:revealSafety .3s ease 1.6s forwards}
      .reveal.inview{opacity:1;transform:translateY(0);transition:opacity .55s ease,transform .55s cubic-bezier(.22,.8,.32,1);transition-delay:var(--d,0ms);animation:none}
      .no-anim .reveal{opacity:1;transform:none;animation:none}

      /* ---------- brand bar ---------- */
      .brand-bar{max-width:1280px;margin:0 auto;padding:18px clamp(16px,4vw,36px) 0;display:flex;align-items:center;justify-content:space-between;gap:12px;flex-wrap:wrap}
      .brand-mark{display:inline-flex;align-items:center;gap:10px;text-decoration:none;color:#0f172a;font-weight:800;font-size:20px;letter-spacing:-.02em}
      .brand-mark .brand-ico{width:36px;height:36px;flex:none;border-radius:11px;background:linear-gradient(135deg,#0f766e,#0284c7);display:inline-flex;align-items:center;justify-content:center;box-shadow:0 8px 18px rgba(15,118,110,.25)}
      .brand-mark .brand-sub{display:block;font-size:11.5px;font-weight:700;color:#0284c7;letter-spacing:.04em}
      .brand-domain{font-size:13.5px;font-weight:700;color:#475569;background:#f0fdfa;border:1px solid #99f6e4;border-radius:999px;padding:6px 12px}
      @media (max-width:640px){.brand-bar{padding-top:14px}.brand-mark{font-size:18px}.brand-domain{font-size:12.5px}}

      /* ---------- hero / intro ---------- */
      .intro{position:relative;overflow:hidden;margin-top:22px;padding:clamp(24px,4.5vw,44px);border-radius:26px;
        border:1px solid rgba(255,255,255,.75);box-shadow:var(--shadow-lg);animation:heroIn .65s cubic-bezier(.22,.8,.32,1) both;
        background:linear-gradient(120deg,#f0fdf4,#eff6ff,#fffbeb,#fdf2f8,#ecfeff,#f0fdf4);background-size:220% 220%}

      .intro::before,.intro::after{content:"";position:absolute;border-radius:50%;pointer-events:none}
      .intro::before{width:190px;height:190px;right:-46px;top:-66px;background:radial-gradient(circle at 35% 35%,rgba(255,255,255,.95),rgba(125,211,252,.45) 58%,transparent 72%);animation:floaty 7s ease-in-out infinite}
      .intro::after{width:130px;height:130px;right:16%;bottom:-72px;background:radial-gradient(circle at 35% 35%,rgba(255,255,255,.9),rgba(253,186,116,.5) 58%,transparent 72%);animation:floaty2 9s ease-in-out infinite}
      .intro>*{position:relative;z-index:1}
      .hero-badge{display:inline-flex;align-items:center;gap:8px;background:rgba(255,255,255,.82);border:1px solid #bae6fd;color:#0369a1;
        font-size:12.5px;font-weight:800;letter-spacing:.06em;text-transform:uppercase;padding:6px 12px;border-radius:999px;margin-bottom:14px;box-shadow:0 4px 14px rgba(2,132,199,.12)}
      
      .hero-badge i{width:8px;height:8px;border-radius:50%;background:#14b8a6;display:inline-block;animation:pulseDot 2s ease-in-out infinite}
      .intro h1{font-size:clamp(30px,5vw,50px);max-width:22ch;color:#0f172a}
      
      .intro h1 .hl{color:#0f766e;background:linear-gradient(transparent 62%,#fde68a 62%);padding:0 2px}
      
      .intro p.lede{font-size:clamp(15.5px,2vw,17.5px);color:#475569;max-width:64ch;margin:14px 0 0}
      
      .privacy-line{display:flex;gap:10px;align-items:flex-start;margin-top:16px;font-size:14px;color:#065f46;
        background:rgba(255,255,255,.85);border:1px solid #a7f3d0;border-radius:14px;padding:12px 14px;max-width:680px}
      
      .privacy-line svg{flex:none;margin-top:1px}
      .searchbar{margin:22px 0 6px;position:relative;max-width:820px}
      .searchbar input{width:100%;font-size:16.5px;padding:17px 18px 17px 50px;border:2px solid #bae6fd;
        border-radius:999px;background:#fff;box-shadow:0 10px 28px rgba(2,132,199,.14);outline:none;transition:border-color .2s,transform .2s}
      
      .searchbar input:focus{border-color:var(--accent);box-shadow:0 12px 32px rgba(15,118,110,.2),0 0 0 5px rgba(45,212,191,.18);transform:translateY(-1px)}
      .searchbar svg{position:absolute;left:18px;top:50%;transform:translateY(-50%);color:#0284c7}
      .search-meta{font-size:13.5px;color:var(--muted);margin:8px 4px 0;min-height:20px}
      .stats{display:grid;grid-template-columns:repeat(4,1fr);gap:12px;margin:20px 0 4px;max-width:820px}
      .stat{border-radius:16px;padding:14px 16px;border:1px solid rgba(255,255,255,.8);box-shadow:0 8px 20px rgba(30,41,59,.08);animation:popIn .5s both}
      .stat:nth-child(1){background:#dcfce7;animation-delay:.05s}.stat:nth-child(2){background:#dbeafe;animation-delay:.12s}
      .stat:nth-child(3){background:#fef3c7;animation-delay:.19s}.stat:nth-child(4){background:#fce7f3;animation-delay:.26s}
      
      .stat b{display:block;font-size:clamp(22px,3vw,28px);font-weight:800;color:#0f172a;line-height:1.1}
      
      .stat span{font-size:12.5px;color:#475569;font-weight:600}
      
      .chips{display:flex;flex-wrap:wrap;gap:8px;margin:20px 0 2px}
      .chip{border:1px solid var(--line);background:#fff;color:var(--ink);border-radius:999px;padding:8px 14px;font-size:13.5px;font-weight:600;text-decoration:none;transition:transform .18s,background .18s}
      
      .chip:nth-child(3n+1){background:#ecfdf5}.chip:nth-child(3n+2){background:#eff6ff}.chip:nth-child(3n){background:#fff7ed}
      
      @media (hover:hover){.chip:hover{transform:translateY(-2px);box-shadow:0 8px 18px rgba(30,41,59,.12);color:var(--accent)}}
      .chip:active{transform:scale(.97)}

      /* ---------- grids & cards ---------- */
      section.block{margin-top:42px;animation:fadeIn .4s both}
      .block-head{display:flex;align-items:center;gap:12px;flex-wrap:wrap;margin-bottom:12px}
      .block-head::before{content:"";width:10px;height:10px;border-radius:3px;background:linear-gradient(135deg,#14b8a6,#38bdf8);flex:none;box-shadow:0 4px 10px rgba(20,184,166,.35)}
      .block-head h2{font-size:clamp(22px,3vw,27px)}
      .block-head .count{color:var(--muted);font-size:13.5px;font-weight:600;background:var(--surface);border:1px solid var(--line);padding:3px 10px;border-radius:999px}
      .block-head p{width:100%;color:var(--muted);margin:2px 0 4px;max-width:78ch;font-size:15px}
      .grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(258px,1fr));gap:14px}
      .card{--cat:#0f766e;--cat-bg:#ccfbf1;position:relative;display:block;background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);
        padding:18px 18px 16px;text-decoration:none;color:var(--ink);box-shadow:var(--shadow);overflow:hidden;
        transition:transform .22s cubic-bezier(.22,.8,.32,1),border-color .22s}
      .card::before{content:"";position:absolute;inset:0 0 auto 0;height:5px;background:var(--cat);opacity:.85}
      .card::after{content:"";position:absolute;inset:0;background:linear-gradient(110deg,transparent 30%,rgba(255,255,255,.35) 48%,transparent 62%);transform:translateX(-120%);pointer-events:none}
      @media (hover:hover){.card:hover{transform:translateY(-5px);border-color:var(--cat);box-shadow:0 14px 30px color-mix(in srgb,var(--cat) 22%,transparent),0 4px 12px rgba(30,41,59,.08)}.card:hover::after{transform:translateX(120%);transition:transform .7s ease}}
      .card:active{transform:scale(.985)}
      .card h3{font-size:16.5px;font-family:inherit;font-weight:750;letter-spacing:-.01em;display:flex;gap:7px;align-items:center;margin-top:2px}
      .card p{margin:6px 0 0;color:var(--muted);font-size:13.5px;line-height:1.5}
      .star{color:#f59e0b;font-size:14px}
      .tag{display:inline-block;margin-top:11px;font-size:11px;font-weight:800;letter-spacing:.05em;text-transform:uppercase;color:var(--cat);background:var(--cat-bg);padding:4px 9px;border-radius:999px}
      .cat-finance{--cat:#16a34a;--cat-bg:#dcfce7}.cat-health{--cat:#e11d48;--cat-bg:#ffe4e6}.cat-math{--cat:#0284c7;--cat-bg:#e0f2fe}
      .cat-text{--cat:#d97706;--cat-bg:#fef3c7}.cat-developer{--cat:#7c3aed;--cat-bg:#ede9fe}.cat-converters{--cat:#0891b2;--cat-bg:#cffafe}
      .cat-datetime{--cat:#ea580c;--cat-bg:#ffedd5}.cat-everyday{--cat:#65a30d;--cat-bg:#ecfccb}.cat-business{--cat:#2563eb;--cat-bg:#dbeafe}
      .cat-security{--cat:#db2777;--cat-bg:#fce7f3}.cat-image{--cat:#c026d3;--cat-bg:#fae8ff}.cat-pdf{--cat:#dc2626;--cat-bg:#fee2e2}
      
      .empty{background:var(--surface);border:1.5px dashed #93c5fd;border-radius:var(--radius);padding:24px;color:var(--muted);animation:popIn .35s both}
      #searchResults section.block{animation:fadeUp .35s both}

      /* ---------- tool page ---------- */
      .crumbs{font-size:13.5px;color:var(--muted);margin:22px 0 12px;display:flex;flex-wrap:wrap;gap:4px}
      .crumbs a{color:var(--muted);text-decoration:none;font-weight:600}.crumbs a:hover{color:var(--accent)}
      .tool-head{background:linear-gradient(120deg,#f0fdf4,#eff6ff,#fffbeb);border:1px solid var(--line);border-radius:22px;padding:clamp(20px,3.5vw,30px);box-shadow:var(--shadow);animation:heroIn .5s both}
      
      .tool-head h1{font-size:clamp(28px,4.6vw,40px)}
      .tool-head .promise{color:var(--muted);margin-top:8px;font-size:15px;max-width:72ch}
      .tool-layout{display:grid;grid-template-columns:1fr 1fr;gap:18px;margin-top:20px;align-items:start}
      .tool-layout>*{animation:fadeUp .5s both}.tool-layout>*:nth-child(2){animation-delay:.08s}.tool-layout>*:nth-child(3){animation-delay:.14s}
      .panel{background:var(--surface);border:1px solid var(--line);border-radius:20px;padding:20px;box-shadow:var(--shadow)}
      .panel h2{font-size:19px;margin-bottom:14px}
      .field{margin-bottom:14px}
      .field label{display:block;font-size:13.5px;font-weight:700;margin-bottom:6px}
      .field label .hint{font-weight:500;color:var(--muted)}
      .field input[type=number],.field input[type=text],.field input[type=date],.field input[type=time],
      .field input[type=datetime-local],.field select,.field textarea,
      .panel input[type=number],.panel input[type=text],.panel input[type=date],.panel input[type=time],
      .panel input[type=datetime-local],.panel select{
        width:100%;padding:11px 13px;border:1.5px solid var(--line);border-radius:12px;background:var(--surface);min-height:46px;transition:border-color .18s}
      .field textarea,.panel textarea{width:100%;padding:11px 13px;border:1.5px solid var(--line);border-radius:12px;background:var(--surface)}
      .field input:focus,.field select:focus,.field textarea:focus,.panel textarea:focus,.panel input:focus,.panel select:focus{border-color:var(--accent);outline:none;box-shadow:0 0 0 4px rgba(45,212,191,.16)}
      .field-row{display:grid;grid-template-columns:1fr 1fr;gap:12px}
      .field-row3{display:grid;grid-template-columns:1fr 1fr 1fr;gap:12px}
      .btn{display:inline-flex;align-items:center;justify-content:center;gap:7px;background:linear-gradient(135deg,#0f766e,#0284c7);color:#fff;border:none;
        border-radius:12px;padding:11px 18px;font-weight:750;min-height:46px;text-decoration:none;font-size:15px;box-shadow:0 8px 18px rgba(15,118,110,.22);
        transition:transform .16s}
      @media (hover:hover){.btn:hover{transform:translateY(-2px);box-shadow:0 12px 24px rgba(2,132,199,.28);filter:brightness(1.05)}}
      .btn:active{transform:scale(.97)}
      .btn.secondary{background:var(--surface);color:var(--ink);border:1.5px solid var(--line);box-shadow:none}
      .btn.small{padding:7px 12px;min-height:38px;font-size:13.5px;border-radius:10px}
      .btn:disabled{opacity:.5;cursor:not-allowed;transform:none}
      .btnrow{display:flex;flex-wrap:wrap;gap:9px;margin-top:14px}
      .result-big{font-size:clamp(28px,4vw,34px);font-weight:800;line-height:1.15;letter-spacing:-.02em;background:#f0fdfa;border:1px solid #99f6e4;border-radius:16px;padding:16px;margin-bottom:10px;animation:resultPop .45s cubic-bezier(.22,.8,.32,1) both}
      
      .result-big small{display:block;font-family:inherit;font-size:12px;font-weight:800;color:var(--accent);letter-spacing:.07em;text-transform:uppercase;margin-bottom:4px}
      .kv{display:flex;justify-content:space-between;gap:14px;padding:9px 2px;border-bottom:1px solid var(--line);font-size:15px;animation:fadeIn .3s both}
      .kv:last-child{border-bottom:none}.kv b{font-variant-numeric:tabular-nums;text-align:right}.kv span{color:var(--muted)}
      .note{font-size:13.5px;color:var(--muted);margin-top:12px}
      .warn{background:var(--amber-soft);border:1px solid #fde68a;border-radius:12px;padding:11px 13px;font-size:13.5px;margin-top:12px;animation:popIn .3s both}
      .err{background:var(--danger-soft);color:var(--danger);border-radius:12px;padding:11px 13px;font-size:14px;margin-top:10px;animation:popIn .3s both}
      .okbox{background:var(--accent-soft);border-radius:12px;padding:11px 13px;font-size:14px;margin-top:10px;animation:popIn .3s both}
      table.data{width:100%;border-collapse:collapse;font-size:13.5px;font-variant-numeric:tabular-nums}
      table.data th,table.data td{padding:7px 9px;border-bottom:1px solid var(--line);text-align:right}
      table.data th:first-child,table.data td:first-child{text-align:left}
      table.data th{color:var(--muted);font-weight:700;background:var(--surface2)}
      .table-scroll{max-width:100%;max-height:340px;overflow:auto;border:1px solid var(--line);border-radius:12px;margin-top:12px;-webkit-overflow-scrolling:touch}
      .howto{margin-top:26px;background:#fffbeb;border:1px solid #fde68a;border-radius:20px;padding:22px;box-shadow:var(--shadow);animation:fadeUp .5s both}
      
      .howto h2{font-size:20px;margin-bottom:8px}.howto p{color:var(--muted);margin:6px 0;font-size:15px}
      .howto code,.formula{font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;background:#fef3c7;padding:2px 7px;border-radius:6px;font-size:.92em;color:var(--ink)}
      
      pre.code{background:var(--code-bg);color:var(--code-ink);border-radius:12px;padding:14px;overflow:auto;font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:13px;line-height:1.5;white-space:pre-wrap;word-break:break-word}
      .related{margin-top:30px}.related h2{font-size:21px;margin-bottom:12px}
      footer.site{margin-top:56px;background:var(--surface);border:1px solid var(--line);border-radius:20px;padding:22px;color:var(--muted);font-size:13.5px;box-shadow:var(--shadow)}
      footer.site h3{font-size:16px;color:var(--ink);font-family:inherit;margin-bottom:6px}
      .seg{display:inline-flex;border:1.5px solid var(--line);border-radius:12px;overflow:hidden;flex-wrap:wrap}
      .seg button{background:var(--surface);border:none;padding:9px 14px;font-size:14px;min-height:42px;transition:background .18s,color .18s}
      .seg button.on{background:var(--accent);color:var(--accent-ink);font-weight:700}
      .keypad{display:grid;grid-template-columns:repeat(5,1fr);gap:8px}
      .keypad button{padding:13px 4px;border:1px solid var(--line);background:var(--surface2);border-radius:12px;font-size:16px;min-height:50px;transition:transform .12s,background .15s}
      .keypad button:active{transform:scale(.94)}
      .keypad button.op{background:var(--accent-soft);font-weight:700}.keypad button.eq{background:var(--accent);color:var(--accent-ink);font-weight:800}
      .swatch{width:100%;height:74px;border-radius:12px;border:1px solid var(--line)}
      .palette-row{display:grid;grid-template-columns:repeat(5,1fr);gap:9px}
      .pal{border-radius:12px;overflow:hidden;border:1px solid var(--line);transition:transform .18s}
      @media (hover:hover){.pal:hover{transform:translateY(-3px)}}
      .pal .c{height:64px}.pal .t{font-size:11.5px;padding:6px 8px;background:var(--surface);font-family:ui-monospace,Menlo,monospace}
      .thumb{max-width:100%;height:auto;border-radius:12px;border:1px solid var(--line)}
      .timer-big{font-size:clamp(42px,9vw,66px);font-weight:800;font-variant-numeric:tabular-nums;text-align:center;letter-spacing:-.02em}
      .diff-add{background:var(--accent-soft)}.diff-del{background:var(--danger-soft);text-decoration:line-through}
      .range-wrap{display:flex;align-items:center;gap:10px}.range-wrap output{font-variant-numeric:tabular-nums;font-weight:700;min-width:44px;text-align:right}
      input[type=range]{flex:1;accent-color:var(--accent);min-height:32px}
      input[type=color]{width:100%;height:48px;border:1.5px solid var(--line);border-radius:12px;background:var(--surface);padding:4px}
      input[type=file]{width:100%;max-width:100%;padding:11px;border:1.5px dashed #93c5fd;border-radius:12px;background:#eff6ff}
      
      img,canvas,video{max-width:100%}
      .invoice-sheet{background:#fff;color:#17211c;border:1px solid var(--line);border-radius:12px;padding:26px;font-size:14px;overflow-x:auto}
      .invoice-sheet h3{font-family:inherit}

      /* ---------- responsive: tablet ---------- */
      @media (max-width:1024px){
        .grid{grid-template-columns:repeat(2,1fr)}
        .stats{grid-template-columns:repeat(4,1fr)}
      }
      @media (max-width:820px){.tool-layout{grid-template-columns:1fr}.tool-layout>*{animation-delay:0s}}
      /* ---------- responsive: mobile ---------- */
      @media (max-width:640px){
        .wrap{padding:0 14px 52px}
        .intro{margin-top:14px;padding:22px 18px 24px;border-radius:22px}
        .intro::before{width:120px;height:120px}
        .grid{grid-template-columns:1fr;gap:12px}
        .stats{grid-template-columns:1fr 1fr;gap:10px}
        .stat{padding:12px 14px}
        .chips{flex-wrap:wrap;overflow:visible}
        .chip{flex:0 1 auto}
        .searchbar input{padding:15px 16px 15px 46px;border-radius:16px}
        .field-row{grid-template-columns:1fr}
        .field-row3{grid-template-columns:1fr 1fr}
        .panel{padding:17px 16px;border-radius:18px}
        .howto{padding:18px 16px}
        .btnrow .btn{flex:1 1 auto}
        .kv{font-size:14px}
        .palette-row{grid-template-columns:repeat(2,1fr)}
        .keypad{gap:6px}.keypad button{min-height:48px;font-size:15px;padding:11px 2px}
        table.data{font-size:12.5px}
        .invoice-sheet{padding:18px 14px}
        section.block{margin-top:34px}
      }
      @media (max-width:380px){.field-row3{grid-template-columns:1fr}.stats{grid-template-columns:1fr 1fr}}
      @media print{body *{visibility:hidden}.invoice-sheet,.invoice-sheet *{visibility:visible}.invoice-sheet{position:absolute;inset:0;border:none}}
      @media (prefers-reduced-motion: reduce){
        *,*::before,*::after{animation-duration:.01ms !important;animation-iteration-count:1 !important;transition-duration:.01ms !important;scroll-behavior:auto !important}
        .reveal{opacity:1 !important;transform:none !important}
        html{scroll-behavior:auto}
      }

      /* ---------- always paint content ----------
         content-visibility:auto was removed: in several phone webviews it left
         below-the-fold sections permanently unpainted (a blank page). Every
         section and card now renders normally, always. */

      /* ---------- currency, SEO copy & FAQ ---------- */
      .currency-note{font-size:12.5px;color:var(--muted);margin:6px 0 0}
      .seo-copy p{color:var(--muted);font-size:15px;margin:8px 0}
      .seo-copy p b{color:var(--ink)}
      .faq-item{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:16px 18px;box-shadow:var(--shadow);margin-bottom:10px}
      .faq-item h3{font-size:16px;margin-bottom:6px}
      .faq-item p{margin:0;color:var(--muted);font-size:14.5px}

      /* ---------- forced light theme: always light, even on dark-mode devices ---------- */
      :root{color-scheme:light}
      html,body{background-color:#ffffff}
      @media (prefers-color-scheme: dark){
        :root{color-scheme:light;--bg:#ffffff;--surface:#ffffff;--surface2:#f8fafc;--ink:#1e293b;--muted:#5b6b82;--line:#e2e8f0;--accent:#0f766e;--accent2:#0284c7;--code-bg:#f1f5f9;--code-ink:#1e293b}
        body{background-color:#ffffff;color:#1e293b}
        .intro{background:linear-gradient(120deg,#f0fdf4,#eff6ff,#fffbeb,#fdf2f8,#ecfeff,#f0fdf4)}
        .tool-head{background:linear-gradient(120deg,#f0fdf4,#eff6ff,#fffbeb)}
        .card,.panel,footer.site,.howto{background:#ffffff}
      }
    

/* Smoothness pass: lighter paint work on small screens */
@media (max-width:640px){
  .card{box-shadow:0 2px 8px rgba(15,23,42,.06)!important}
  .card:hover{transform:none!important}
  [class*="orb"]{animation:none!important}
}
@media (prefers-reduced-motion:reduce){
  *,*::before,*::after{animation-duration:.01ms!important;animation-iteration-count:1!important;transition-duration:.01ms!important}
}


/* ProblemSolverTools Premium 2.0 — light desktop + mobile enhancements */
:root {--bg:#fbfdff;--surface:#fff;--surface2:#f4f8fc;--ink:#142238;--muted:#51647b;--line:#dce6f0;--accent:#096fb4;--accent2:#0891b2;--accent-ink:#fff;--accent-soft:#eaf7ff;--shadow:0 4px 24px rgba(29,57,91,.045);--shadow-lg:0 14px 48px rgba(29,57,91,.07);--radius:20px;--radius-sm:12px}
html {scroll-padding-top:92px;background:#fbfdff}
body {color:var(--ink);background:radial-gradient(ellipse 800px 560px at 92% 2%,#eaf5ff 0,transparent 74%),radial-gradient(ellipse 700px 560px at 8% 10%,#f3f9ff 0,transparent 74%),#fbfdff;overflow-x:clip}
::selection{background:#cfeafe;color:#10406c}
.skip-link{position:fixed;top:-120px;left:12px;z-index:1000;background:#fff;padding:10px 14px;color:var(--accent);border:2px solid var(--accent);border-radius:12px}
.skip-link:focus{top:12px}
.site-header{position:sticky;top:0;z-index:100;background:rgba(255,255,255,.92);border-bottom:1px solid #e6edf5;box-shadow:0 1px 10px rgba(24,52,84,.025);-webkit-backdrop-filter:blur(14px);backdrop-filter:blur(14px)}
.site-header .top-inner{max-width:1320px;margin:auto;padding:0 clamp(16px,3vw,32px);display:flex;align-items:center;justify-content:space-between;gap:22px;min-height:78px}
.site-header .brand-mark{display:inline-flex;gap:12px;align-items:center;text-decoration:none;color:#10223a;font-size:18px;white-space:nowrap;letter-spacing:-.035em}
.brand-mark .brand-ico{width:42px;height:42px;border-radius:14px;background:linear-gradient(145deg,#047ac6,#25b2bc);box-shadow:0 7px 20px rgba(5,121,190,.18)}
.brand-mark .brand-sub{display:block;font-size:10.5px;color:#58819c;font-weight:700;letter-spacing:.065em}
.nav-main{display:flex;align-items:center;gap:6px}
.nav-main>a,.nav-trigger{font-size:13.5px;font-weight:750;color:#4e6177;text-decoration:none;padding:11px 14px;border:1px solid transparent;background:none;border-radius:11px;display:inline-flex;align-items:center;gap:7px;transition:background .18s,color .18s,transform .18s}
.nav-main>a:hover,.nav-trigger:hover{background:#eef8ff;color:#075e9a}
.nav-main .nav-cta{color:#fff;background:linear-gradient(135deg,#0478bb,#0891b2);border-color:transparent;box-shadow:0 4px 12px rgba(7,119,189,.15)}
.nav-main .nav-cta:hover{background:linear-gradient(135deg,#086ba9,#087b9a);color:#fff}
.nav-details{position:relative}
.nav-details summary{list-style:none;cursor:pointer}.nav-details summary::-webkit-details-marker{display:none}
.nav-details[open] .nav-trigger{background:#eef8ff;color:#0369a1}
.nav-panel{position:absolute;top:calc(100% + 11px);right:0;min-width:510px;display:grid;grid-template-columns:1fr 1fr;gap:5px;padding:13px;background:#fff;border:1px solid var(--line);border-radius:17px;box-shadow:0 15px 45px rgba(36,65,96,.14)}
.nav-panel a{font-size:13px;color:#334e68;text-decoration:none;font-weight:650;display:flex;align-items:center;gap:8px;padding:10px;border-radius:10px;transition:background .18s}
.nav-panel a:hover{background:#eef7fe;color:#0369a1}
.nav-panel .nav-emoji{font-size:17px;width:25px}
.wrap{max-width:1320px;padding:0 clamp(16px,3vw,32px) 60px}
.intro{margin-top:26px;padding:clamp(30px,4vw,52px);background:radial-gradient(circle at 90% 15%,rgba(153,221,253,.30),transparent 35%),linear-gradient(125deg,#f5faff 0%,#f1f9ff 45%,#f7fdfe 100%);border:1px solid #e0eef8;border-radius:28px;box-shadow:var(--shadow-lg);animation:heroIn .45s ease-out both}
.intro::before{width:270px;height:270px;right:-65px;top:-98px;opacity:.65;animation:floaty 11s ease-in-out infinite}
.intro::after{width:180px;height:180px;right:13%;bottom:-110px;opacity:.5;animation:floaty2 14s ease-in-out infinite}
.intro h1{font-size:clamp(33px,4.2vw,56px);letter-spacing:-.055em;max-width:21ch}
.intro h1 .hl{color:#087bb7;background:linear-gradient(transparent 78%,#a9e5fa 78%)}
.intro p.lede{max-width:67ch;color:#506983;line-height:1.75;font-size:clamp(15px,1.45vw,18px)}
.hero-badge{background:white;color:#086baf;border:1px solid #d0eafd;box-shadow:none;text-transform:none;letter-spacing:0}
.privacy-line{color:#375e6c;background:#ffffffbd;border:1px solid #d5edf3;box-shadow:none;font-size:13px}
.searchbar{max-width:720px;margin-top:27px}
.searchbar input{border:1.5px solid #c9deee;border-radius:16px;box-shadow:0 6px 20px rgba(27,79,114,.07);padding:18px 16px 18px 53px;font-size:16px;min-height:58px;transition:border-color .18s,box-shadow .18s}
.searchbar input:focus{transform:none;box-shadow:0 5px 19px rgba(27,79,114,.075),0 0 0 4px #dff3ff;border-color:#1894cc}
.stats{max-width:720px;grid-template-columns:repeat(3,1fr)}
.stat,.stat:nth-child(n){background:#fff;border:1px solid #ddeaf4;box-shadow:none;animation:fadeUp .4s both}
.stat:nth-child(2){background:#f4faff}.stat:nth-child(3){background:#f1fbf9}
.stat b{color:#0972ad}
.chips{margin-top:23px;gap:8px}.chip,.chip:nth-child(n){color:#375a71;background:#fff;border-color:#d7e7f4;font-weight:650}
.chip:hover{background:#e9f6ff;color:#04679f}
section.block{margin-top:51px;animation:none}
.block-head{gap:11px;margin-bottom:17px}.block-head h2{font-size:clamp(22px,2.6vw,31px);letter-spacing:-.04em}
.block-head::before{background:linear-gradient(160deg,#0799b6,#4dc0d0)}
.block-head p{color:#657b8e;font-size:14px;line-height:1.65}
.grid{grid-template-columns:repeat(auto-fill,minmax(258px,1fr));gap:15px}
.card{border:1px solid #e3ebf4;border-radius:17px;padding:20px;min-height:180px;box-shadow:0 4px 18px rgba(27,56,88,.035);transition:transform .22s cubic-bezier(.2,.8,.2,1),box-shadow .22s,border-color .22s;will-change:auto}
.card::before{height:3px;background:var(--cat);opacity:.65}
.card::after{display:none}
.card h3{color:#142a40;font-size:15.5px;line-height:1.4;letter-spacing:-.02em;margin-top:11px}
.card p{font-size:13px;line-height:1.65;color:#62758a;margin-top:8px}
.card .tag{letter-spacing:0;text-transform:none;font-weight:700;font-size:11px;margin-top:13px;padding:4px 8px}
.card-top{display:flex;align-items:center;justify-content:space-between}
.card-icon{display:inline-flex;align-items:center;justify-content:center;height:37px;width:37px;border-radius:12px;background:var(--cat-bg);color:var(--cat)}
.card-icon svg{width:19px;height:19px}
.card-open{color:#94a9bc;font-size:15px;transform:translateX(0);transition:transform .18s,color .18s}
@media (hover:hover){.card:hover{transform:translateY(-3px);border-color:#b9ddec;box-shadow:0 14px 35px rgba(30,70,110,.085)}.card:hover .card-open{transform:translateX(3px);color:#027eba}}
.reveal{opacity:1;transform:none;animation:none}.reveal.inview{opacity:1;transform:none;animation:none;transition:none}
.tool-head{background:linear-gradient(115deg,#f4fbff,#f7fbff);border:1px solid #dfedf5;box-shadow:none;border-radius:20px;padding:clamp(24px,4vw,40px)}
.tool-head h1{letter-spacing:-.05em;color:#17324c;font-size:clamp(27px,4vw,43px)}
.tool-head .promise{max-width:72ch;line-height:1.75}
.tool-layout{gap:20px;margin-top:22px}
.tool-layout>*{animation:fadeUp .3s ease-out both}
.tool-layout>.panel:nth-child(2){position:sticky;top:99px}
.panel{border:1px solid #dfeaf4;box-shadow:var(--shadow);padding:24px;border-radius:18px}
.panel h2{font-size:20px;color:#213952}
.field input:focus,.field textarea:focus,.panel input:focus,.panel textarea:focus,.field select:focus,.panel select:focus{box-shadow:0 0 0 4px #e1f2fd;border-color:#118dc6}
.btn{background:linear-gradient(130deg,#087cb7,#0892b3);box-shadow:0 5px 12px rgba(11,127,180,.14);border-radius:11px}
.btn:hover{filter:none}
.result-big{background:linear-gradient(140deg,#effaff,#f3fffc);border:1px solid #b7e4eb}
.howto{background:#fff;border:1px solid #dcebf5;box-shadow:none}
.benefits{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px}.benefit{border:1px solid #deebf5;background:#fff;border-radius:17px;padding:20px}.benefit>b{display:inline-flex;padding:6px 9px;border-radius:9px;background:#eaf6ff;color:#0782bc;font-size:12px}.benefit h3{font-size:16px;margin:13px 0 8px}.benefit p{font-size:13px;color:#657b90;margin:0;line-height:1.65}
.crumbs{margin:25px 0 15px;gap:8px;align-items:center;font-size:13px}.crumbs a{color:#447596}.crumbs a:hover{text-decoration:underline}
.site-footer{background:#f3f8fc;border-top:1px solid #e1ebf2;margin-top:66px}
.footer-inner{max-width:1320px;margin:auto;padding:40px clamp(16px,3vw,32px) 25px;display:grid;grid-template-columns:1.3fr .8fr .8fr;gap:32px}
.footer-inner h2{font-size:18px;color:#183854}.footer-inner h3{font-size:14px;margin:0 0 12px;color:#233e58}.footer-inner p{font-size:13px;color:#61788e;line-height:1.75;max-width:52ch;margin:12px 0}.footer-inner a{display:block;color:#59738d;font-size:13px;text-decoration:none;margin:8px 0}.footer-inner a:hover{color:#087cb7;text-decoration:underline}
.footer-bottom{max-width:1320px;margin:auto;border-top:1px solid #dfe9f1;padding:16px clamp(16px,3vw,32px) 22px;font-size:12px;color:#697e90}
.article-content{max-width:920px;margin:36px auto;padding:28px;background:#fff;border:1px solid #dfe8f1;border-radius:19px;box-shadow:var(--shadow);line-height:1.75}
.article-content h1{font-size:clamp(28px,4vw,42px);margin-bottom:12px}.article-content h2{font-size:22px;margin:26px 0 10px}.article-content p,.article-content li{color:#566b7f;font-size:15px}
.tool-noscript{margin-top:18px}.tool-noscript a{font-weight:700}
.mini-tool-list{display:grid;grid-template-columns:repeat(auto-fill,minmax(245px,1fr));gap:12px}.mini-tool-list a{padding:15px;background:#fff;border:1px solid var(--line);border-radius:12px;text-decoration:none;color:#285270;font-weight:700}.mini-tool-list a:hover{background:#edf8ff}
/* Keep important content on screen in odd mobile webviews */
#app{min-height:40vh}.no-anim .reveal{opacity:1}
@media(max-width:1000px){.nav-main{gap:2px}.nav-main>a,.nav-trigger{padding:10px 8px}.nav-panel{right:-12px}}
@media(max-width:820px){.tool-layout>.panel:nth-child(2){position:static}.nav-main .nav-hide-tablet{display:none}.footer-inner{grid-template-columns:1fr 1fr}.footer-inner>div:first-child{grid-column:1/-1}}
@media(max-width:640px){
 .site-header .top-inner{min-height:66px;padding:0 14px;gap:8px}.site-header .brand-mark{font-size:15px;gap:7px}.brand-mark .brand-ico{width:37px;height:37px;border-radius:11px}.site-header .brand-mark .brand-sub{font-size:8.5px;letter-spacing:.03em}
 .nav-main>a.nav-hide-mobile{display:none}.nav-main .nav-cta{padding:10px 11px;font-size:12px}.nav-trigger{font-size:12px;padding:9px 10px}.nav-panel{position:fixed;top:65px;left:10px;right:10px;min-width:0;grid-template-columns:1fr 1fr;max-height:60vh;overflow:auto;box-shadow:0 15px 40px rgba(25,55,88,.14)}
 .wrap{padding:0 14px 42px}.intro{padding:25px 20px 26px;border-radius:20px;margin-top:16px}.intro h1{font-size:clamp(30px,9vw,41px);line-height:1.13}.intro::before{width:125px;height:125px;right:-50px;top:-53px}.intro::after{width:95px;height:95px;bottom:-47px}.hero-badge{font-size:11px}.intro p.lede{font-size:14px;line-height:1.7}.privacy-line{font-size:12px}.searchbar input{font-size:15px;padding:15px 14px 15px 47px;min-height:54px}.stats{gap:8px}.stat{padding:11px 12px}.stat b{font-size:21px}.stat span{font-size:11px}.chips{max-height:112px;overflow:auto;scrollbar-width:thin}.chip{font-size:12px;padding:7px 10px}
 section.block{margin-top:36px}.grid{grid-template-columns:1fr;gap:11px}.card{min-height:0;padding:17px;border-radius:15px;box-shadow:0 2px 10px rgba(27,56,88,.035)}.card h3{margin-top:8px}.card p{margin-top:5px}.card-icon{width:34px;height:34px}.benefits{grid-template-columns:1fr}.footer-inner{grid-template-columns:1fr;gap:12px;padding-top:30px}.footer-inner>div:first-child{grid-column:auto}.tool-head{padding:21px 18px;border-radius:16px}.tool-layout{gap:15px}.panel{padding:19px 16px}.article-content{padding:20px 17px;border-radius:15px}
}
@media(max-width:360px){.site-header .brand-mark{font-size:13.5px}.site-header .nav-cta{display:none}.site-header .top-inner{gap:4px}.site-header .brand-ico{width:32px;height:32px}.site-header .brand-sub{font-size:7.8px}}
@media(prefers-reduced-motion:reduce){.intro::before,.intro::after{animation:none}.card,.btn,.chip{transition:none}}
@media print{.site-header,.site-footer,.intro::before,.intro::after{display:none!important}}