:root{--bg:#f6f8fa;--surface:#fff;--text:#16202b;--muted:#5a6875;--border:#d9e0e7;--accent:#0b5cad;--accent-hover:#094c92;--ok:#18794e;--ok-bg:#e6f4ea;--bad:#b42318;--bad-bg:#fdecea;--warn:#9a6700;--warn-bg:#fff4d6;--radius:8px;--maxw:46rem;--font:system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif}*{box-sizing:border-box}.visually-hidden{clip:rect(0 0 0 0);clip-path:inset(50%);white-space:nowrap;border:0;width:1px;height:1px;margin:-1px;padding:0;position:absolute;overflow:hidden}html{-webkit-text-size-adjust:100%}body{font-family:var(--font);background:var(--bg);color:var(--text);margin:0;line-height:1.6}a{color:var(--accent)}.container{max-width:var(--maxw);margin:0 auto;padding:1rem}.site-header{border-bottom:1px solid var(--border);background:var(--surface)}.site-header .container{justify-content:space-between;align-items:center;gap:1rem;padding-top:.75rem;padding-bottom:.75rem;display:flex}.brand{color:var(--text);font-size:1.1rem;font-weight:700;text-decoration:none}.site-nav a{color:var(--muted);font-size:.9rem;text-decoration:none}.site-nav a:hover,.site-nav a:focus{color:var(--accent)}.site-footer{border-top:1px solid var(--border);background:var(--surface);margin-top:3rem}.site-footer .container{color:var(--muted);padding-top:1rem;padding-bottom:1rem;font-size:.85rem}.tool{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:1.25rem}.form-row{flex-direction:column;gap:.5rem;display:flex}@media (min-width:34rem){.form-row{flex-direction:row}}.form-row input[type=email]{border:1px solid var(--border);border-radius:var(--radius);flex:1;min-width:0;padding:.6rem .75rem;font-family:inherit;font-size:1rem}.form-row input[type=email]:focus-visible{outline:2px solid var(--accent);outline-offset:1px}button[type=submit]{border-radius:var(--radius);background:var(--accent);color:#fff;cursor:pointer;border:none;padding:.6rem 1.4rem;font-family:inherit;font-size:1rem;font-weight:600}button[type=submit]:hover{background:var(--accent-hover)}button[type=submit]:focus-visible{outline:2px solid var(--text);outline-offset:2px}button[type=submit]:disabled{opacity:.6;cursor:wait}.form-hint{color:var(--muted);margin:.5rem 0 0;font-size:.85rem}.result{border-top:1px solid var(--border);margin-top:1.25rem;padding-top:1rem}.verdict{border-radius:999px;margin:0 0 .25rem;padding:.25rem .75rem;font-size:1.05rem;font-weight:700;display:inline-block}.verdict--valide{background:var(--ok-bg);color:var(--ok)}.verdict--invalide{background:var(--bad-bg);color:var(--bad)}.verdict--indetermine{background:var(--warn-bg);color:var(--warn)}.result-detail{color:var(--muted);margin:.25rem 0 .75rem;font-size:.95rem}.steps{border:1px solid var(--border);border-radius:var(--radius);margin:.75rem 0;padding:0;list-style:none;overflow:hidden}.steps li{align-items:baseline;gap:.6rem;padding:.55rem .85rem;font-size:.95rem;display:flex}.steps li+li{border-top:1px solid var(--border)}.steps .stage{min-width:4.5rem;font-weight:600}.steps .ok-true{color:var(--ok);font-weight:700}.steps .ok-false{color:var(--bad);font-weight:700}.steps .ok-null{color:var(--warn);font-weight:700}.suggestion{margin:.75rem 0 0;font-size:.95rem}.suggestion button{color:var(--accent);cursor:pointer;font:inherit;background:0 0;border:none;padding:0;text-decoration:underline}.notice{color:var(--muted);background:var(--bg);border-radius:var(--radius);margin:.75rem 0 0;padding:.6rem .75rem;font-size:.85rem}.error-box{background:var(--bad-bg);color:var(--bad);border-radius:var(--radius);margin:.75rem 0 0;padding:.6rem .75rem;font-size:.95rem}.content section{margin-top:2rem}.content h2{margin-bottom:.5rem;font-size:1.25rem}.content p,.content li{color:var(--text)}.content .lead{color:var(--muted);font-size:1.05rem}.cards{grid-template-columns:1fr;gap:.75rem;margin:0;padding:0;list-style:none;display:grid}@media (min-width:40rem){.cards{grid-template-columns:repeat(3,1fr)}}.cards li{border:1px solid var(--border);border-radius:var(--radius);background:var(--surface);padding:.85rem}.cards h3{margin:0 0 .25rem;font-size:1rem}.cards p{color:var(--muted);margin:0;font-size:.9rem}