:root {
        --bg: #f4f6f5;
        --surface: #ffffff;
        --surface-2: #eef2f0;
        --ink: #12211e;
        --ink-2: #43554f;
        --ink-3: #6d7f78;
        --line: #d8e0dc;
        --teal: #00707c;
        --teal-dark: #00555f;
        --teal-soft: #e0f0ef;
        --amber: #b97a16;
        --amber-soft: #fdf3e0;
        --green: #1c7a3d;
        --green-soft: #e4f3e8;
        --red: #b3372c;
        --shadow: 0 1px 2px rgba(18, 33, 30, .06), 0 8px 24px rgba(18, 33, 30, .06);
        color-scheme: light;
      }
      :root[data-theme="dark"] {
        --bg: #0d1514;
        --surface: #15201e;
        --surface-2: #1b2926;
        --ink: #e8f0ed;
        --ink-2: #a9bcb5;
        --ink-3: #7d9189;
        --line: #2a3a36;
        --teal: #3ec6cf;
        --teal-dark: #7fdde4;
        --teal-soft: #123034;
        --amber: #e5a83e;
        --amber-soft: #33270f;
        --green: #5ec97e;
        --green-soft: #14301d;
        --red: #e07a6e;
        --shadow: 0 1px 2px rgba(0,0,0,.4), 0 8px 24px rgba(0,0,0,.35);
        color-scheme: dark;
      }
      * { box-sizing: border-box; }
      html { scroll-behavior: smooth; }
      body {
        margin: 0;
        background: var(--bg);
        color: var(--ink);
        font-family: "Archivo", system-ui, -apple-system, "Segoe UI", sans-serif;
        font-size: 16px;
        line-height: 1.55;
        -webkit-font-smoothing: antialiased;
      }
      .mono { font-family: "IBM Plex Mono", ui-monospace, monospace; }
      a { color: var(--teal); }
      a:hover { color: var(--teal-dark); }

      /* ---------- header ---------- */
      header.site {
        position: sticky; top: 0; z-index: 50;
        background: var(--surface);
        border-bottom: 1px solid var(--line);
      }
      .header-in {
        max-width: 1120px; margin: 0 auto; padding: 10px 16px;
        display: flex; align-items: center; gap: 18px; flex-wrap: wrap;
      }
      .wordmark {
        font-weight: 800; font-size: 17px; letter-spacing: -.02em; color: var(--ink);
        text-decoration: none; white-space: nowrap;
      }
      .wordmark span { color: var(--teal); }
      nav.main { display: flex; flex-wrap: wrap; gap: 2px 4px; margin-left: auto; }
      nav.main a {
        color: var(--ink-2); text-decoration: none; font-size: 13.5px; font-weight: 600;
        padding: 6px 9px; border-radius: 8px;
      }
      nav.main a:hover { background: var(--surface-2); color: var(--ink); }
      .menu-btn {
        display: none; appearance: none; border: 1px solid var(--line); background: var(--surface);
        color: var(--ink-2); padding: 8px; border-radius: 999px; cursor: pointer;
        align-items: center; justify-content: center; line-height: 0;
      }
      .menu-btn:hover { border-color: var(--teal); color: var(--ink); }
      @media (max-width: 880px) {
        .header-in { gap: 10px; padding: 9px 14px; }
        .wordmark { margin-right: auto; }
        .menu-btn { display: inline-flex; }
        nav.main {
          display: none; order: 4; flex-basis: 100%; margin-left: 0;
          padding: 8px 0 4px; border-top: 1px solid var(--line);
          grid-template-columns: 1fr 1fr; gap: 2px;
        }
        nav.main.open { display: grid; }
        nav.main a { padding: 11px 10px; font-size: 14.5px; border-radius: 10px; }
      }

      .wrap { max-width: 1120px; margin: 0 auto; padding: 0 16px; }

      /* ---------- hero ---------- */
      .hero { padding: 34px 0 8px; }
      .hero h1 {
        font-size: clamp(28px, 4.6vw, 42px); line-height: 1.08; letter-spacing: -.025em;
        font-weight: 800; margin: 0 0 10px; max-width: 720px;
      }
      .hero h1 em { font-style: normal; color: var(--teal); }
      .hero p.lede { font-size: 17px; color: var(--ink-2); max-width: 640px; margin: 0 0 6px; }
      .hero .updated { font-size: 13px; color: var(--ink-3); margin: 0; }

      /* ---------- tool rail ---------- */
      .rail {
        display: flex; flex-wrap: wrap; gap: 8px; margin: 22px 0 18px;
      }
      .rail button {
        appearance: none; border: 1px solid var(--line); background: var(--surface);
        color: var(--ink-2); font: inherit; font-size: 14px; font-weight: 600;
        padding: 9px 14px; border-radius: 999px; cursor: pointer;
      }
      .rail button:hover { border-color: var(--teal); color: var(--ink); }
      .rail button[aria-selected="true"] {
        background: var(--teal); border-color: var(--teal); color: #fff;
      }
      :root[data-theme="dark"] .rail button[aria-selected="true"] { color: #06282c; }

      /* ---------- calculator card ---------- */
      .calc {
        background: var(--surface); border: 1px solid var(--line); border-radius: 16px;
        box-shadow: var(--shadow); overflow: hidden;
      }
      .calc-head { padding: 20px 22px 4px; }
      .calc-head h2 { font-size: 21px; letter-spacing: -.015em; margin: 0 0 4px; font-weight: 800; }
      .calc-head p { margin: 0; color: var(--ink-2); font-size: 14.5px; max-width: 620px; }
      .calc-body {
        display: grid; grid-template-columns: 1fr 1fr; gap: 0;
      }
      .calc-inputs { padding: 18px 22px 22px; }
      .calc-results {
        padding: 18px 22px 22px; background: var(--surface-2);
        border-left: 1px solid var(--line);
      }
      @media (max-width: 760px) {
        .calc-body { grid-template-columns: 1fr; }
        .calc-results { border-left: none; border-top: 1px solid var(--line); }
      }
      .field { margin-bottom: 14px; }
      .field label {
        display: block; font-size: 13px; font-weight: 600; color: var(--ink-2);
        margin-bottom: 5px;
      }
      .field .hint { font-weight: 400; color: var(--ink-3); font-size: 12px; margin-top: 4px; }
      .money {
        display: flex; align-items: stretch; border: 1px solid var(--line);
        border-radius: 10px; background: var(--surface); overflow: hidden;
      }
      .money span.cur {
        display: flex; align-items: center; padding: 0 11px; background: var(--surface-2);
        color: var(--ink-2); font-weight: 600; font-size: 15px; border-right: 1px solid var(--line);
      }
      .money input {
        border: 0; outline: 0; background: transparent; color: var(--ink);
        font: inherit; font-size: 16px; padding: 10px 12px; width: 100%; min-width: 0;
      }
      .money:focus-within { border-color: var(--teal); box-shadow: 0 0 0 3px var(--teal-soft); }
      select.input, input.plain {
        width: 100%; border: 1px solid var(--line); border-radius: 10px; background: var(--surface);
        color: var(--ink); font: inherit; font-size: 15px; padding: 10px 12px; outline: 0;
      }
      select.input:focus, input.plain:focus { border-color: var(--teal); box-shadow: 0 0 0 3px var(--teal-soft); }
      .range-row { display: flex; align-items: center; gap: 12px; }
      .range-row input[type="range"] { flex: 1; accent-color: var(--teal); }
      .range-row .val { font-family: "IBM Plex Mono", monospace; font-size: 14px; min-width: 52px; text-align: right; }
      .toggle-row { display: flex; align-items: center; gap: 10px; font-size: 14px; font-weight: 600; color: var(--ink-2); }
      .toggle-row input { width: 18px; height: 18px; accent-color: var(--teal); }

      .keep-label { font-size: 12.5px; font-weight: 700; letter-spacing: .06em; text-transform: uppercase; color: var(--ink-3); }
      .keep-value {
        font-family: "IBM Plex Mono", monospace; font-size: 38px; font-weight: 600;
        letter-spacing: -.02em; line-height: 1.1; margin: 2px 0 2px;
      }
      .keep-sub { font-size: 13.5px; color: var(--ink-2); margin-bottom: 16px; }
      .lines { border-top: 1px solid var(--line); }
      .line {
        display: flex; justify-content: space-between; gap: 14px;
        padding: 8px 0; border-bottom: 1px solid var(--line); font-size: 14.5px;
      }
      .line .k { color: var(--ink-2); }
      .line .v { font-family: "IBM Plex Mono", monospace; font-size: 14px; white-space: nowrap; }
      .line.total { font-weight: 700; }
      .line.total .k { color: var(--ink); }
      .note {
        font-size: 13px; color: var(--ink-2); background: var(--amber-soft);
        border-radius: 10px; padding: 10px 12px; margin-top: 14px; line-height: 1.5;
      }
      .note.blue { background: var(--teal-soft); }
      .note strong { color: var(--ink); }

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

      /* ---------- sections ---------- */
      section.block { padding: 34px 0 6px; }
      section.block > h2 {
        font-size: 24px; letter-spacing: -.02em; font-weight: 800; margin: 0 0 6px;
      }
      section.block > p.intro { color: var(--ink-2); max-width: 680px; margin: 0 0 18px; }

      table.compare {
        width: 100%; border-collapse: collapse; background: var(--surface);
        border: 1px solid var(--line); border-radius: 14px; overflow: hidden;
        font-size: 14.5px;
      }
      table.compare th, table.compare td { padding: 11px 14px; text-align: left; border-bottom: 1px solid var(--line); }
      table.compare th { background: var(--surface-2); font-size: 12.5px; text-transform: uppercase; letter-spacing: .05em; color: var(--ink-3); }
      table.compare td.num, table.compare th.num { text-align: right; font-family: "IBM Plex Mono", monospace; font-size: 14px; }
      table.compare tr:last-child td { border-bottom: 0; }
      table.compare tr.best td { background: var(--green-soft); }
      .best-tag {
        font-size: 11px; font-weight: 700; color: var(--green); border: 1px solid var(--green);
        border-radius: 999px; padding: 1px 7px; margin-left: 8px; vertical-align: 2px; white-space: nowrap;
      }
      .compare-controls { display: flex; flex-wrap: wrap; gap: 14px; align-items: end; margin-bottom: 14px; }
      .compare-controls .field { margin: 0; min-width: 180px; }
      .seg { display: inline-flex; border: 1px solid var(--line); border-radius: 10px; overflow: hidden; }
      .seg button {
        appearance: none; border: 0; background: var(--surface); color: var(--ink-2);
        font: inherit; font-weight: 700; font-size: 14px; padding: 9px 16px; cursor: pointer;
      }
      .seg button[aria-pressed="true"] { background: var(--teal); color: #fff; }
      :root[data-theme="dark"] .seg button[aria-pressed="true"] { color: #06282c; }
      @media (max-width: 640px) {
        table.compare th:nth-child(3), table.compare td:nth-child(3) { display: none; }
        table.compare th, table.compare td { padding: 8px; font-size: 13px; }
        table.compare td.num, table.compare th.num { font-size: 12.5px; }
        .best-tag { display: none; }
      }

      /* ---------- guide cards ---------- */
      .guides { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
      @media (max-width: 760px) { .guides { grid-template-columns: 1fr; } }
      .guide {
        background: var(--surface); border: 1px solid var(--line); border-radius: 14px;
        padding: 20px 22px;
      }
      .guide h3 { margin: 0 0 4px; font-size: 17px; font-weight: 800; letter-spacing: -.01em; }
      .guide .fee-line {
        font-family: "IBM Plex Mono", monospace; font-size: 13.5px; color: var(--teal-dark);
        background: var(--teal-soft); border-radius: 8px; padding: 7px 10px; margin: 10px 0 12px;
      }
      .guide p { margin: 0 0 10px; font-size: 14.5px; color: var(--ink-2); }
      .guide p strong { color: var(--ink); }
      .guide .src { font-size: 12px; color: var(--ink-3); margin: 0; }
      .guide .src a { color: var(--ink-3); text-decoration: underline; }

      /* ---------- FAQ ---------- */
      .faq { border: 1px solid var(--line); border-radius: 14px; background: var(--surface); overflow: hidden; }
      .faq details { border-bottom: 1px solid var(--line); }
      .faq details:last-child { border-bottom: 0; }
      .faq summary {
        cursor: pointer; font-weight: 700; font-size: 15.5px; padding: 15px 18px; list-style: none;
      }
      .faq summary::-webkit-details-marker { display: none; }
      .faq summary::after { content: "+"; float: right; color: var(--teal); font-weight: 800; }
      .faq details[open ] summary::after { content: "–"; }
      .faq .a { padding: 0 18px 16px; color: var(--ink-2); font-size: 14.5px; max-width: 760px; }
      .faq .a p { margin: 0 0 8px; }

      /* ---------- static pages ---------- */
      .page { display: none; max-width: 780px; }
      .page.active { display: block; }
      .page h2 { font-size: 26px; letter-spacing: -.02em; font-weight: 800; margin: 26px 0 10px; }
      .page h3 { font-size: 17px; margin: 22px 0 6px; }
      .page p, .page li { color: var(--ink-2); font-size: 15.5px; }
      .page p { margin: 0 0 12px; }
      .page a.btn {
        display: inline-block; background: var(--teal); color: #fff; text-decoration: none;
        font-weight: 700; padding: 11px 18px; border-radius: 10px; font-size: 15px;
      }
      :root[data-theme="dark"] .page a.btn { color: #06282c; }

      footer.site {
        margin-top: 44px; border-top: 1px solid var(--line); background: var(--surface);
      }
      .footer-in {
        max-width: 1120px; margin: 0 auto; padding: 26px 16px 34px;
        display: grid; grid-template-columns: 1.4fr 1fr 1fr; gap: 24px;
      }
      @media (max-width: 700px) { .footer-in { grid-template-columns: 1fr; } }
      footer.site h4 { margin: 0 0 10px; font-size: 13px; text-transform: uppercase; letter-spacing: .06em; color: var(--ink-3); }
      footer.site ul { list-style: none; margin: 0; padding: 0; }
      footer.site li { margin-bottom: 6px; }
      footer.site a { color: var(--ink-2); text-decoration: none; font-size: 14px; }
      footer.site a:hover { color: var(--teal); }
      footer.site p { font-size: 13px; color: var(--ink-3); margin: 0 0 8px; max-width: 420px; }
      .verified { font-size: 12.5px; color: var(--ink-3); margin: 8px 0 0; }
      .verified a { color: var(--ink-3); text-decoration: underline; }
      .theme-btn {
        appearance: none; border: 1px solid var(--line); background: var(--surface);
        color: var(--ink-2); font: inherit; font-size: 13px; font-weight: 700;
        padding: 7px 12px; border-radius: 999px; cursor: pointer; white-space: nowrap;
      }
      .theme-btn:hover { border-color: var(--teal); color: var(--ink); }
      .sources li { margin-bottom: 4px; word-break: break-all; }