:root{--blue:#2563eb;--dark:#0f172a;--muted:#475569;--light:#eff6ff;--border:#dbeafe}
*{box-sizing:border-box}body{margin:0;font-family:system-ui,-apple-system,Segoe UI,Roboto,Arial,sans-serif;color:var(--dark);background:#fff;line-height:1.6}
a{color:var(--blue)}header{border-bottom:1px solid var(--border);background:#fff}header .wrap,footer .wrap,main{max-width:1000px;margin:0 auto;padding:0 20px}
header .wrap{display:flex;align-items:center;gap:12px;flex-wrap:wrap;padding-top:14px;padding-bottom:14px}
.brand{display:flex;align-items:center;gap:10px;text-decoration:none;color:var(--dark);font-weight:800;font-size:20px}
.brand img{width:40px;height:40px}nav{display:flex;gap:14px;flex-wrap:wrap;margin-left:auto}nav a{text-decoration:none;font-weight:600}
main{padding:28px 20px 48px}.hero{background:var(--light);border:1px solid var(--border);border-radius:14px;padding:28px}
h1{font-size:34px;line-height:1.2}h2{margin-top:32px}.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:16px;margin-top:20px}
.card{border:1px solid var(--border);border-radius:12px;padding:18px;background:#fff}.card a{font-weight:700;text-decoration:none;font-size:18px}
.tool{background:#f8fafc;border:1px solid var(--border);border-radius:12px;padding:20px;margin-top:20px}
label{display:block;margin:10px 0 4px;font-weight:600}input,select,textarea{width:100%;padding:10px;border:1px solid #cbd5e1;border-radius:8px;font:inherit}
button{background:var(--blue);color:#fff;border:0;padding:10px 16px;border-radius:8px;font-weight:700;cursor:pointer;margin:8px 6px 8px 0}
button.secondary{background:#fff;color:var(--blue);border:1px solid var(--blue)}.result{background:#fff;border:1px solid var(--border);border-radius:10px;padding:16px;margin-top:16px;white-space:pre-wrap}
table{width:100%;border-collapse:collapse;margin-top:14px}th,td{border:1px solid var(--border);padding:8px;text-align:left}
footer{border-top:1px solid var(--border);background:#f8fafc;padding:28px 0}footer img{width:160px}footer nav{display:flex;gap:12px;flex-wrap:wrap;margin:12px 0}
.small{color:var(--muted)}.flash{perspective:800px;cursor:pointer}.flash-inner{border:1px solid var(--border);border-radius:12px;padding:32px;text-align:center;background:#fff;min-height:160px;display:flex;align-items:center;justify-content:center;font-size:20px}
@media(max-width:640px){h1{font-size:26px}nav{margin-left:0}}