:root{
    --paper:#F4F5F1; --card:#FFFFFF; --ink:#1C2B27; --muted:#5B6B64;
    --accent:#0F6B58; --accent-deep:#0A4A3D; --accent-soft:#E3F0EB;
    --amber:#9A5B00; --amber-soft:#FBF3E4; --line:#E0E4DD;
    --radius:14px;
  }
  *{box-sizing:border-box;margin:0;padding:0}
  html{scroll-behavior:smooth}
  @media (prefers-reduced-motion: reduce){ html{scroll-behavior:auto} *{transition:none!important;animation:none!important} }
  body{
    font-family:'Inter',system-ui,-apple-system,sans-serif;
    background:var(--paper); color:var(--ink);
    font-size:16px; line-height:1.55;
  }
  .wrap{max-width:1060px;margin:0 auto;padding:0 20px}

  header{border-bottom:1px solid var(--line);background:var(--card)}
  .head-in{display:flex;align-items:center;justify-content:space-between;padding:16px 0}
  .wordmark{font-family:'Archivo',sans-serif;font-weight:800;font-size:18px;letter-spacing:-.02em}
  .wordmark span{color:var(--accent)}
  .year-badge{font-family:'Archivo',sans-serif;font-weight:700;font-size:13px;background:var(--accent-soft);color:var(--accent-deep);padding:4px 12px;border-radius:99px}

  .hero{padding:40px 0 8px}
  h1{font-family:'Archivo',sans-serif;font-weight:800;font-size:clamp(28px,4.5vw,42px);letter-spacing:-.03em;line-height:1.1;max-width:640px}
  .hero p{color:var(--muted);margin-top:10px;max-width:560px}

  .grid{display:grid;grid-template-columns:1fr 400px;gap:24px;padding:28px 0 8px;align-items:start}
  @media(max-width:880px){.grid{grid-template-columns:1fr}}

  .card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:24px}
  .card h2{font-family:'Archivo',sans-serif;font-weight:700;font-size:15px;text-transform:uppercase;letter-spacing:.06em;color:var(--muted);margin-bottom:16px}

  .parents{display:grid;grid-template-columns:1fr 1fr;gap:16px}
  @media(max-width:480px){.parents{grid-template-columns:1fr}}
  .field{margin-bottom:16px}
  label{display:block;font-weight:600;font-size:14px;margin-bottom:6px}
  label small{display:block;font-weight:400;color:var(--muted);font-size:12.5px}
  input[type=number]{
    width:100%;padding:11px 12px;border:1.5px solid var(--line);border-radius:9px;
    font-family:'Inter',sans-serif;font-size:16px;font-variant-numeric:tabular-nums;
    background:#FCFCFB;color:var(--ink);
  }
  input[type=number]:focus{outline:2px solid var(--accent);outline-offset:1px;border-color:var(--accent)}
  .prefix{position:relative}
  .prefix::before{content:"$";position:absolute;left:12px;top:50%;transform:translateY(-50%);color:var(--muted);font-size:15px}
  .prefix input{padding-left:26px}

  .stepper{display:flex;align-items:center;gap:0;border:1.5px solid var(--line);border-radius:9px;overflow:hidden;background:#FCFCFB}
  .stepper button{
    width:44px;height:44px;border:none;background:transparent;font-size:20px;color:var(--accent);
    cursor:pointer;font-weight:600;flex-shrink:0;
  }
  .stepper button:hover{background:var(--accent-soft)}
  .stepper button:focus-visible{outline:2px solid var(--accent);outline-offset:-3px}
  .stepper .val{flex:1;text-align:center;font-weight:600;font-variant-numeric:tabular-nums}

  input[type=range]{width:100%;accent-color:var(--accent);height:32px;cursor:pointer}
  input[type=range]:focus-visible{outline:2px solid var(--accent);outline-offset:4px}
  .care-read{display:flex;justify-content:space-between;font-size:13.5px;color:var(--muted);font-variant-numeric:tabular-nums;margin-top:2px}
  .care-read b{color:var(--ink)}

  details.advanced{margin-top:8px;border-top:1px dashed var(--line);padding-top:14px}
  details.advanced summary{cursor:pointer;font-weight:600;font-size:14px;color:var(--accent-deep);list-style:none;display:flex;align-items:center;gap:6px}
  details.advanced summary::before{content:"+";font-family:'Archivo';font-weight:700;font-size:16px}
  details.advanced[open] summary::before{content:"–"}
  details.advanced summary::-webkit-details-marker{display:none}
  details.advanced .inner{padding-top:14px}
  .hint{font-size:12.5px;color:var(--muted);margin-top:4px}

  .result{position:sticky;top:20px}
  .transfer{
    background:var(--accent-deep);color:#fff;border-radius:var(--radius);
    padding:26px 24px;overflow:hidden;position:relative;
  }
  .transfer::after{
    content:"";position:absolute;inset:auto -30px -50px auto;width:180px;height:180px;
    border-radius:50%;background:radial-gradient(circle,rgba(255,255,255,.09),transparent 70%);
  }
  .direction{font-family:'Archivo',sans-serif;font-weight:700;font-size:13px;text-transform:uppercase;letter-spacing:.1em;opacity:.85;display:flex;align-items:center;gap:8px}
  .direction .arrow{letter-spacing:-.18em;color:#8FD6C3}
  .big-figure{font-family:'Archivo',sans-serif;font-weight:800;font-size:clamp(40px,6vw,54px);letter-spacing:-.03em;line-height:1;margin:14px 0 2px;font-variant-numeric:tabular-nums}
  .per{font-size:15px;opacity:.8}
  .annual-line{margin-top:14px;padding-top:14px;border-top:1px solid rgba(255,255,255,.18);font-size:14px;opacity:.9;font-variant-numeric:tabular-nums}

  .period-toggle{display:flex;gap:4px;background:rgba(255,255,255,.12);border-radius:9px;padding:4px;margin-top:18px;position:relative;z-index:1}
  .period-toggle button{
    flex:1;border:none;background:transparent;color:#fff;padding:8px 4px;border-radius:6px;
    font-family:'Inter';font-size:13px;font-weight:600;cursor:pointer;opacity:.75;
  }
  .period-toggle button[aria-pressed=true]{background:#fff;color:var(--accent-deep);opacity:1}
  .period-toggle button:focus-visible{outline:2px solid #fff;outline-offset:1px}

  .note{background:var(--amber-soft);border:1px solid #EBD9B4;color:var(--amber);border-radius:10px;padding:12px 14px;font-size:13.5px;margin-top:14px;display:none}
  .note.show{display:block}

  .no-transfer .direction .arrow{display:none}

  .working{padding:8px 0 8px}
  details.steps{background:var(--card);border:1px solid var(--line);border-radius:var(--radius)}
  details.steps summary{
    cursor:pointer;padding:20px 24px;font-family:'Archivo',sans-serif;font-weight:700;font-size:16px;
    display:flex;justify-content:space-between;align-items:center;list-style:none;
  }
  details.steps summary::-webkit-details-marker{display:none}
  details.steps summary .chev{transition:transform .2s;color:var(--accent)}
  details.steps[open] summary .chev{transform:rotate(180deg)}
  .steps-table{width:100%;border-collapse:collapse;font-size:14.5px}
  .steps-table td{padding:13px 24px;border-top:1px solid var(--line);vertical-align:top}
  .steps-table td:last-child{text-align:right;font-variant-numeric:tabular-nums;font-weight:600;white-space:nowrap}
  .steps-table .step-n{font-family:'Archivo';font-weight:700;color:var(--accent);width:34px;padding-right:0}
  .steps-table .sub{color:var(--muted);font-size:13px;font-weight:400;display:block;margin-top:2px}

  .explain{padding:28px 0 20px;max-width:720px}
  .explain h2{font-family:'Archivo',sans-serif;font-weight:800;font-size:24px;letter-spacing:-.02em;margin-bottom:12px}
  .explain h3{font-family:'Archivo',sans-serif;font-weight:700;font-size:17px;margin:22px 0 8px}
  .explain p{color:#33413C;margin-bottom:10px}

  .disclaimer{background:var(--card);border:1px solid var(--line);border-left:4px solid var(--accent);border-radius:10px;padding:16px 20px;font-size:13.5px;color:var(--muted);margin:8px 0 32px}
  footer{border-top:1px solid var(--line);padding:24px 0 40px;font-size:13px;color:var(--muted)}
  footer .wrap{display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap}

/* nav + article pages */
.nav-links{display:flex;gap:18px;align-items:center;font-size:14px;font-weight:600}
.nav-links a{color:var(--muted);text-decoration:none}
.nav-links a:hover{color:var(--accent-deep)}
.article{padding:36px 0 20px;max-width:720px}
.article h1{font-size:clamp(26px,4vw,36px)}
.article .lede{color:var(--muted);margin-top:10px;font-size:17px}
.article h2{font-family:'Archivo',sans-serif;font-weight:800;font-size:22px;letter-spacing:-.02em;margin:28px 0 10px}
.article p{color:#33413C;margin-bottom:12px}
.article table{width:100%;border-collapse:collapse;font-size:14.5px;margin:14px 0;background:var(--card);border:1px solid var(--line);border-radius:10px;overflow:hidden}
.article th{font-family:'Archivo';font-weight:700;text-align:left;padding:10px 14px;background:var(--accent-soft);color:var(--accent-deep);font-size:13px;text-transform:uppercase;letter-spacing:.05em}
.article td{padding:10px 14px;border-top:1px solid var(--line);font-variant-numeric:tabular-nums}
.cta{display:inline-block;background:var(--accent);color:#fff;font-family:'Archivo';font-weight:700;padding:13px 22px;border-radius:10px;text-decoration:none;margin:16px 0}
.cta:hover{background:var(--accent-deep)}
.guides{padding:8px 0 28px}
.guides h2{font-family:'Archivo',sans-serif;font-weight:800;font-size:22px;letter-spacing:-.02em;margin-bottom:14px}
.guide-cards{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}
@media(max-width:720px){.guide-cards{grid-template-columns:1fr}}
.guide-cards a{display:block;background:var(--card);border:1px solid var(--line);border-radius:12px;padding:18px;text-decoration:none;color:var(--ink)}
.guide-cards a:hover{border-color:var(--accent)}
.guide-cards b{font-family:'Archivo';font-weight:700;display:block;margin-bottom:6px}
.guide-cards span{font-size:13.5px;color:var(--muted)}
footer nav{display:flex;gap:16px}
footer a{color:var(--muted)}