:root{--ink:#1a2332;--muted:#5b6b7f;--bg:#fff;--soft:#f4f7fb;--line:#e2e8f0;--accent:#0d6efd;--accent2:#0a7d4f}
*{box-sizing:border-box}
body{margin:0;font:16px/1.65 system-ui,-apple-system,Segoe UI,Roboto,sans-serif;color:var(--ink);background:var(--bg)}
header,footer{padding:1rem clamp(1rem,4vw,2rem);border-bottom:1px solid var(--line);display:flex;flex-wrap:wrap;gap:1rem;align-items:center;justify-content:space-between}
footer{border:0;border-top:1px solid var(--line);display:block;color:var(--muted);font-size:.9rem;margin-top:3rem}
.brand{font-weight:800;font-size:1.15rem;color:var(--ink);text-decoration:none}
nav a{color:var(--muted);text-decoration:none;margin-left:1rem;font-size:.95rem}
nav a:hover{color:var(--accent)}
main{max-width:760px;margin:0 auto;padding:0 clamp(1rem,4vw,2rem)}
h1{font-size:clamp(1.6rem,4vw,2.3rem);line-height:1.2;margin:2rem 0 1rem}
h2{margin:2.2rem 0 .6rem;font-size:1.4rem}
h3{margin:1.6rem 0 .4rem}
a{color:var(--accent)}
.lead{font-size:1.15rem;color:var(--muted)}
.tool{background:var(--soft);border:1px solid var(--line);border-radius:14px;padding:1.25rem;margin:1.5rem 0}
.tool label{display:block;font-weight:600;margin:.7rem 0 .25rem;font-size:.95rem}
.tool input,.tool select{width:100%;padding:.6rem .7rem;border:1px solid var(--line);border-radius:8px;font:inherit}
.grid{display:grid;grid-template-columns:1fr 1fr;gap:1rem}
.result{margin-top:1.2rem;padding:1rem;background:#fff;border:1px solid var(--line);border-radius:10px}
.big{font-size:2rem;font-weight:800;color:var(--accent2)}
table{border-collapse:collapse;width:100%;margin:1rem 0}
th,td{border:1px solid var(--line);padding:.55rem .7rem;text-align:left}
th{background:var(--soft)}
.faq dt{font-weight:700;margin-top:1.1rem}
.faq dd{margin:.3rem 0 0;color:var(--muted)}
.disclaimer{font-size:.8rem}
@media(max-width:520px){.grid{grid-template-columns:1fr}}
/* --- Tool widgets (textarea-based utilities) --- */
.tool textarea{width:100%;padding:.7rem;border:1px solid var(--line);border-radius:8px;font:14px/1.5 ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;resize:vertical;background:#fff}
.toolbar{display:flex;flex-wrap:wrap;gap:.5rem;align-items:center;margin:.6rem 0}
.summary{color:var(--muted);font-size:.9rem;margin-left:auto}
.btn{background:var(--accent);color:#fff;border:0;border-radius:8px;padding:.55rem 1rem;font:inherit;font-weight:600;cursor:pointer}
.btn:hover{filter:brightness(1.07)}
.btn-ghost{background:#fff;color:var(--ink);border:1px solid var(--line);border-radius:8px;padding:.45rem .8rem;font:inherit;cursor:pointer}
.btn-ghost:hover{border-color:var(--accent);color:var(--accent)}
.ivc-status{font-weight:600;padding:.6rem .8rem;border-radius:8px;background:#fff;border:1px solid var(--line)}
.ivc-status.ivc-clean{background:#e9f9f0;border-color:#9be0bb;color:#0a7d4f}
.ivc-status.ivc-flag{background:#fff4e5;border-color:#ffd591;color:#b4690e}
.highlight{min-height:3rem;background:#fff;border:1px solid var(--line);border-radius:8px;padding:.7rem;font:14px/1.7 ui-monospace,Menlo,Consolas,monospace;white-space:pre-wrap;word-break:break-word;overflow-wrap:anywhere}
.ivc-mark{font:11px/1 ui-monospace,monospace;font-weight:700;padding:1px 3px;border-radius:4px;color:#fff;vertical-align:middle}
.ivc-mark.ivc-zerowidth{background:#d6336c}
.ivc-mark.ivc-space{background:#1c7ed6}
.ivc-mark.ivc-control{background:#495057}
.ivc-mark.ivc-bidi{background:#9c36b5}
.ivc-mark.ivc-tag{background:#e8590c}
.ivc-mark.ivc-typo{background:#2f9e44}
.ivc-tag{display:inline-block;font-size:.78rem;font-weight:600;color:#fff;padding:1px 7px;border-radius:999px}
.ivc-tag.ivc-zerowidth{background:#d6336c}
.ivc-tag.ivc-space{background:#1c7ed6}
.ivc-tag.ivc-control{background:#495057}
.ivc-tag.ivc-bidi{background:#9c36b5}
.ivc-tag.ivc-tag{background:#e8590c}
.ivc-tag.ivc-typo{background:#2f9e44}
.ivc-table{font-size:.92rem}
.report{margin:.6rem 0}
.options{border:1px solid var(--line);border-radius:8px;padding:.8rem 1rem;margin:1rem 0}
.options legend{padding:0 .4rem}
.options label{display:block;font-weight:400;margin:.35rem 0;cursor:pointer}
.crumbs{font-size:.85rem;color:var(--muted);margin-top:1rem}
.crumbs a{color:var(--muted)}
details.faq{border:1px solid var(--line);border-radius:8px;padding:.5rem .9rem;margin:.5rem 0;background:var(--soft)}
details.faq summary{font-weight:700;cursor:pointer}
details.faq p{color:var(--muted);margin:.6rem 0 .2rem}