:root{--bg:#f8fafc;--card:#ffffff;--ink:#0f172a;--muted:#475569;--accent:#0ea5e9}
*{box-sizing:border-box}body{background:var(--bg);color:var(--ink);font-family:Inter,Segoe UI,Roboto,Arial,sans-serif;margin:0}
.container{max-width:1100px;margin:0 auto;padding:20px}
.site-header{background:#ffffff;border-bottom:1px solid #e6eef5;position:sticky;top:0;z-index:20}
.header-inner{display:flex;align-items:center;justify-content:space-between;padding:12px 0}
.brand{font-weight:700;color:var(--accent);text-decoration:none;font-size:20px}
.nav a{margin-left:12px;color:var(--muted);text-decoration:none;padding:8px;border-radius:8px}
.nav a:hover{background:#f1f9ff;color:var(--ink)}
.hero{display:flex;gap:18px;margin-top:18px;align-items:flex-start;flex-wrap:wrap}
.card{background:var(--card);border:1px solid #edf6fb;border-radius:12px;padding:18px;box-shadow:0 6px 20px rgba(16,24,40,0.04)}
.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:16px;margin-top:16px}
.tool{padding:14px;border-radius:10px;border:1px solid #f1f8fb;background:linear-gradient(180deg,#ffffff,#fbfeff)}
.tool h3{margin:0;color:var(--ink)}
.small{font-size:13px;color:var(--muted)}
.input, textarea, select{width:100%;padding:10px;border-radius:10px;border:1px solid #e6eef5;background:#fff;color:var(--ink)}
.btn{padding:10px 12px;border-radius:10px;background:var(--accent);color:#fff;border:none;cursor:pointer;font-weight:600}
.btn.secondary{background:#64748b}
.result{background:#f8fafc;border:1px dashed #e6eef5;padding:12px;border-radius:8px}
footer.site-footer{margin-top:28px;padding:20px 0;text-align:center;color:var(--muted);font-size:14px;border-top:1px solid #eef6fb}
@media (max-width:800px){.hero{flex-direction:column}}