:root{
  --blue:#2563eb; --blue-dark:#1e40af; --blue-soft:#eff6ff;
  --slate:#0f172a; --muted:#64748b; --line:#e2e8f0; --bg:#f8fafc;
  --card:#ffffff; --green:#059669; --radius:16px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Inter,Arial,sans-serif;
  color:var(--slate);background:var(--bg);line-height:1.6;font-size:16px}
a{color:var(--blue);text-decoration:none}
a:hover{text-decoration:underline}
.wrap{max-width:1080px;margin:0 auto;padding:0 18px}
/* header */
.site-header{background:var(--card);border-bottom:1px solid var(--line);position:sticky;top:0;z-index:50;
  box-shadow:0 2px 14px rgba(15,23,42,.06)}
.site-header .wrap{display:flex;align-items:center;justify-content:space-between;min-height:60px;gap:14px}
.brand{font-weight:800;font-size:1.25rem;color:var(--slate);display:flex;align-items:center;gap:8px;flex:none;white-space:nowrap}
.brand .logo{width:32px;height:32px;flex:none;border-radius:9px;background:linear-gradient(135deg,var(--blue),#60a5fa);
  display:inline-flex;align-items:center;justify-content:center;color:#fff;font-size:17px}
nav.main{display:flex;gap:4px;align-items:center}
nav.main>a,.drop-btn{color:var(--slate);font-weight:600;padding:9px 13px;border-radius:10px;font-size:.95rem;white-space:nowrap}
nav.main>a:hover,.drop-btn:hover{background:var(--blue-soft);text-decoration:none;color:var(--blue-dark)}
.has-drop{position:relative}
.drop-btn{background:none;border:none;font-family:inherit;cursor:pointer;display:inline-flex;align-items:center;gap:5px;min-height:44px}
.drop-btn .car{font-size:.7rem;transition:transform .25s ease}
.has-drop:hover .car,.has-drop:focus-within .car{transform:rotate(180deg)}
.dropdown{position:absolute;top:calc(100% + 8px);left:50%;transform:translate(-50%,8px);width:560px;max-width:94vw;
  background:#fff;border:1px solid var(--line);border-radius:14px;box-shadow:0 24px 50px rgba(15,23,42,.16);
  padding:10px;display:grid;grid-template-columns:1fr 1fr;gap:2px;opacity:0;visibility:hidden;transition:.25s ease;z-index:60}
.has-drop:hover .dropdown,.has-drop:focus-within .dropdown{opacity:1;visibility:visible;transform:translate(-50%,0)}
.dropdown a{color:var(--slate);font-weight:600;padding:10px 12px;border-radius:9px;font-size:.93rem;display:block}
.dropdown a:hover{background:var(--blue-soft);text-decoration:none;color:var(--blue-dark)}
.m-tools{display:none}
#navToggle{display:none;background:none;border:1px solid var(--line);border-radius:10px;font-size:1.3rem;
  padding:6px 12px;cursor:pointer;color:var(--slate);min-height:44px;min-width:44px}
/* hero */
.hero{background:linear-gradient(135deg,#0f172a 0%,#1e3a8a 55%,#2563eb 100%);color:#fff;padding:60px 0 68px;position:relative;overflow:hidden}
.hero:before{content:"";position:absolute;top:-140px;right:-100px;width:420px;height:420px;border-radius:50%;
  background:radial-gradient(circle,rgba(255,255,255,.22),rgba(255,255,255,0) 65%)}
.hero .wrap{position:relative}
.hero h1{margin:0 0 12px;font-size:2.15rem;line-height:1.2;letter-spacing:-.02em}
.hero p.sub{opacity:.92;font-size:1.08rem;max-width:640px;margin:0 0 22px}
.hero-badges{display:flex;gap:10px;flex-wrap:wrap;font-size:.85rem;margin-bottom:26px}
.hero-badges span{background:rgba(255,255,255,.16);padding:6px 14px;border-radius:999px}
.hero-cta{display:inline-flex;align-items:center;gap:8px;background:#fff;color:var(--blue-dark);font-weight:800;
  padding:14px 28px;border-radius:12px;font-size:1.02rem;min-height:48px;box-shadow:0 10px 24px rgba(0,0,0,.22);
  transition:transform .25s ease,box-shadow .25s ease}
.hero-cta:hover{transform:translateY(-2px) scale(1.02);box-shadow:0 16px 32px rgba(0,0,0,.28);text-decoration:none}
@keyframes rise{from{opacity:0;transform:translateY(14px)}to{opacity:1;transform:none}}
.hero h1{animation:rise .7s ease both}
.hero p.sub{animation:rise .7s .08s ease both}
.hero-badges{animation:rise .7s .16s ease both}
.hero-cta{animation:rise .7s .24s ease both}
/* entrance reveal (JS-gated: content is visible without JS) */
.anim .reveal{opacity:0;transform:translateY(16px);transition:opacity .6s ease,transform .6s ease}
.anim .reveal.in{opacity:1;transform:none}
/* tool cards */
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:18px;margin:36px 0}
.tool-card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);
  padding:24px;transition:transform .25s ease,box-shadow .25s ease;display:block}
.tool-card:hover{transform:translateY(-5px);box-shadow:0 18px 36px rgba(37,99,235,.16);text-decoration:none}
.tool-card .icon{width:52px;height:52px;border-radius:14px;margin-bottom:12px;color:var(--blue);
  background:linear-gradient(135deg,var(--blue-soft),#dbeafe);display:flex;align-items:center;justify-content:center}
.tool-card .icon svg{width:27px;height:27px}
.tool-card h3{margin:0 0 8px;font-size:1.15rem;color:var(--slate)}
.tool-card p{margin:0;color:var(--muted);font-size:.94rem}
/* tool page layout */
.tool-hero{background:linear-gradient(135deg,#0f172a,#1e3a8a);color:#fff;padding:40px 0}
.tool-hero h1{margin:0 0 8px;font-size:1.8rem;letter-spacing:-.02em}
.tool-hero p{margin:0;opacity:.9;max-width:680px}
.calculator{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);
  padding:26px;margin:-34px 0 30px;box-shadow:0 10px 30px rgba(15,23,42,.08);position:relative}
.field{margin-bottom:16px}
.field label{display:block;font-weight:700;margin-bottom:6px;font-size:.95rem}
.field input,.field select{width:100%;padding:12px 14px;border:1.5px solid var(--line);border-radius:12px;
  font-size:1rem;font-family:inherit}
.field input:focus,.field select:focus{outline:none;border-color:var(--blue);box-shadow:0 0 0 3px var(--blue-soft)}
.field-row{display:grid;grid-template-columns:1fr 1fr;gap:14px}
.field-row3{display:grid;grid-template-columns:2fr 1fr auto;gap:10px;align-items:end;margin-bottom:12px}
.field-row3 .field{margin-bottom:0}
.btn{background:linear-gradient(135deg,var(--blue),var(--blue-dark));color:#fff;border:none;border-radius:12px;
  padding:14px 26px;font-size:1rem;font-weight:700;cursor:pointer;width:100%;min-height:48px;position:relative;
  overflow:hidden;box-shadow:0 8px 20px rgba(37,99,235,.25);transition:transform .25s ease,box-shadow .25s ease}
.btn:hover{transform:translateY(-2px) scale(1.01);box-shadow:0 13px 28px rgba(37,99,235,.32)}
.btn:after{content:"";position:absolute;top:0;left:-80%;width:45%;height:100%;
  background:linear-gradient(105deg,transparent,rgba(255,255,255,.45),transparent);transform:skewX(-20deg);transition:left .5s ease}
.btn:hover:after{left:135%}
.btn-ghost{background:var(--blue-soft);color:var(--blue-dark)}
.result{background:#f0fdf4;border:1.5px solid #bbf7d0;border-radius:12px;padding:18px;margin-top:18px;display:none}
.result.show{display:block}
.result .big{font-size:1.9rem;font-weight:800;color:var(--green)}
.result .detail{color:var(--muted);font-size:.92rem;margin-top:6px}
.result table{width:100%;border-collapse:collapse;margin-top:10px;font-size:.95rem}
.result table th,.result table td{border:1px solid var(--line);padding:8px 10px;text-align:left;background:#fff}
.result table th{background:var(--blue-soft)}
.tabs{display:flex;gap:8px;margin-bottom:18px;flex-wrap:wrap}
.tabs button{border:1.5px solid var(--line);background:#fff;border-radius:999px;padding:9px 18px;
  font-weight:700;cursor:pointer;font-size:.92rem;color:var(--slate)}
.tabs button.active{background:var(--blue);border-color:var(--blue);color:#fff}
/* dynamic rows, stat cards, tables, textarea */
.field textarea{width:100%;padding:12px 14px;border:1.5px solid var(--line);border-radius:12px;
  font-size:1rem;font-family:inherit;min-height:170px;resize:vertical}
.field textarea:focus{outline:none;border-color:var(--blue);box-shadow:0 0 0 3px var(--blue-soft)}
.area-row{border:1.5px solid var(--line);border-radius:12px;padding:16px;margin-bottom:14px;background:#fcfcff}
.area-row .area-head{display:flex;justify-content:space-between;align-items:center;margin-bottom:10px}
.area-row .area-head strong{font-size:.98rem}
.btn-small{background:var(--blue-soft);color:var(--blue-dark);border:none;border-radius:10px;
  padding:9px 16px;font-weight:700;cursor:pointer;font-size:.9rem}
.btn-small:hover{background:#dbeafe}
.btn-danger{background:#fef2f2;color:#b91c1c}
.btn-danger:hover{background:#fee2e2}
.stats{display:grid;grid-template-columns:repeat(auto-fill,minmax(138px,1fr));gap:12px;margin-top:4px}
.stat{background:var(--blue-soft);border-radius:12px;padding:14px 10px;text-align:center}
.stat .num{font-size:1.45rem;font-weight:800;color:var(--blue-dark);line-height:1.2}
.stat .lab{font-size:.8rem;color:var(--muted);font-weight:700;margin-top:3px}
table.bagtable{width:100%;border-collapse:collapse;margin-top:10px;font-size:.95rem}
table.bagtable th,table.bagtable td{border:1px solid var(--line);padding:8px 10px;text-align:left}
table.bagtable th{background:var(--blue-soft)}
.topwords{margin-top:16px}
.topwords li{color:#334155}
/* content sections */
.section{margin:40px 0}
.section h2{font-size:1.45rem;margin:0 0 14px;letter-spacing:-.01em}
.prose{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:26px}
.prose h3{margin:22px 0 8px;font-size:1.1rem}
.prose h3:first-child{margin-top:0}
.prose p,.prose li{color:#334155}
.faq details{border:1px solid var(--line);border-radius:12px;padding:14px 16px;margin-bottom:10px;background:#fff}
.faq summary{font-weight:700;cursor:pointer}
/* network (sister tool kits) */
.network{background:#fff;border-top:1px solid var(--line);padding:34px 0 38px;margin-top:60px}
.network h3{margin:0 0 6px;font-size:1.15rem;color:var(--slate)}
.network p{margin:0 0 16px;color:var(--muted);font-size:.93rem}
.net-row{display:flex;flex-wrap:wrap;gap:10px}
.net-row a{border:1px solid var(--line);background:var(--bg);color:var(--slate);font-weight:700;font-size:.93rem;
  padding:10px 18px;border-radius:999px;transition:transform .25s ease,border-color .25s ease,background .25s ease}
.net-row a:hover{border-color:var(--blue);background:var(--blue-soft);color:var(--blue-dark);transform:translateY(-2px);text-decoration:none}
/* footer */
.site-footer{background:var(--slate);color:#cbd5e1;padding:40px 0}
.site-footer .wrap{display:grid;grid-template-columns:1.4fr 1fr 1fr;gap:28px}
.site-footer h4{color:#fff;margin:0 0 12px;font-size:1rem}
.site-footer a{color:#cbd5e1;display:block;margin-bottom:8px;font-size:.93rem}
.site-footer p{font-size:.9rem;margin:0 0 10px}
.bottom-bar{border-top:1px solid #1e293b;margin-top:28px;padding-top:18px;font-size:.85rem;color:#94a3b8}
/* breadcrumbs */
.crumbs{font-size:.85rem;color:var(--muted);margin:18px 0 0}
.crumbs a{color:var(--muted)}
@media(max-width:760px){
  nav.main{display:none;position:absolute;top:60px;left:0;right:0;background:#fff;max-height:calc(100vh - 60px);overflow:auto;
    flex-direction:column;align-items:stretch;padding:10px 18px 18px;border-bottom:1px solid var(--line);
    box-shadow:0 24px 40px rgba(15,23,42,.14)}
  nav.main.open{display:flex}
  nav.main>a{padding:13px 12px}
  .has-drop{display:none}
  .m-tools{display:block;border-top:1px solid var(--line);margin-top:8px;padding-top:10px}
  .m-tools .m-title{display:block;font-weight:800;font-size:.85rem;text-transform:uppercase;letter-spacing:.06em;
    color:var(--muted);padding:4px 12px 8px}
  .m-tools a{display:block;color:var(--slate);font-weight:600;padding:11px 12px;border-radius:10px;font-size:.95rem}
  .m-tools a:hover{background:var(--blue-soft);text-decoration:none}
  #navToggle{display:block}
  .hero h1{font-size:1.65rem}
  .field-row,.field-row3{grid-template-columns:1fr}
  .site-footer .wrap{grid-template-columns:1fr}
  .calculator{margin-top:-24px;padding:20px}
}
@media (prefers-reduced-motion: reduce){
  *,*:before,*:after{animation:none!important;transition:none!important}
  .anim .reveal{opacity:1;transform:none}
  html{scroll-behavior:auto}
}