/* ============================================================
   QuickTaxTools — Design System v2.0  "Elevate"
   Typography: Space Grotesk (display) + Inter (UI/body)
   Light & dark themes via CSS variables ([data-theme])
   ============================================================ */
:root{
  --accent:#2563eb;--accent-2:#7c3aed;--accent-soft:#e8efff;
  --grad:linear-gradient(135deg,#2563eb 0%,#6d4aff 100%);
  --navy:#101b36;--green:#0a9d63;--green-light:#e4f8ef;
  --red:#e0455c;--amber:#c07c00;--amber-light:#fff7e6;
  --ink:#18223a;--ink-soft:#46536e;--ink-faint:#7c89a6;
  --bg:#f3f5fa;--bg-accent:#eef2fb;--card:#ffffff;--line:#e4e9f3;
  --th-bg:#13203f;--th-text:#ffffff;--row-alt:#f7f9fd;
  --hero-text:#ffffff;--hero-sub:#c7d4f5;
  --radius:16px;--radius-sm:10px;
  --shadow:0 1px 2px rgba(13,25,55,.05),0 6px 20px rgba(13,25,55,.06);
  --shadow-lift:0 10px 32px rgba(37,99,235,.16),0 2px 8px rgba(13,25,55,.08);
  --font:'Inter',-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  --display:'Space Grotesk',var(--font);
  --header-bg:rgba(255,255,255,.82);
  color-scheme:light;
}
[data-theme="dark"]{
  --accent:#5b8cff;--accent-2:#9d7bff;--accent-soft:#1a2747;
  --grad:linear-gradient(135deg,#3b6dff 0%,#8a5cff 100%);
  --navy:#e8edfb;--green:#3fd69a;--green-light:#0e2b20;
  --red:#ff6b81;--amber:#ffc14d;--amber-light:#2b2210;
  --ink:#e6ebf7;--ink-soft:#aab6d3;--ink-faint:#7585a8;
  --bg:#0a0f1f;--bg-accent:#0d1428;--card:#111a31;--line:#212d4d;
  --th-bg:#1a2748;--th-text:#dfe7fb;--row-alt:#141e38;
  --shadow:0 1px 2px rgba(0,0,0,.3),0 8px 24px rgba(0,0,0,.35);
  --shadow-lift:0 12px 36px rgba(59,109,255,.25),0 2px 8px rgba(0,0,0,.4);
  --header-bg:rgba(10,15,31,.8);
  color-scheme:dark;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{font-family:var(--font);color:var(--ink);background:var(--bg);line-height:1.7;font-size:16.5px;transition:background .3s,color .3s}
::selection{background:rgba(109,74,255,.25)}
img{max-width:100%;height:auto}
a{color:var(--accent);text-decoration:none}
a:hover{text-decoration:underline}
:focus-visible{outline:3px solid var(--accent);outline-offset:2px;border-radius:4px}
.container{max-width:1140px;margin:0 auto;padding:0 22px}
.narrow{max-width:880px}
h1,h2,h3,.logo,.result-hero .big,.stat .v{font-family:var(--display)}

/* ---------- Header: glass ---------- */
.site-header{background:var(--header-bg);backdrop-filter:blur(14px);-webkit-backdrop-filter:blur(14px);border-bottom:1px solid var(--line);position:sticky;top:0;z-index:50}
.header-inner{display:flex;align-items:center;justify-content:space-between;height:64px;gap:10px}
.logo{display:flex;align-items:center;gap:10px;font-weight:700;font-size:1.24rem;color:var(--navy);letter-spacing:-.4px}
.logo:hover{text-decoration:none}
.logo svg{flex:none;filter:drop-shadow(0 2px 6px rgba(37,99,235,.35))}
.logo .tld{background:var(--grad);-webkit-background-clip:text;background-clip:text;color:transparent}
.main-nav{display:flex;gap:2px;align-items:center}
.main-nav a{padding:8px 14px;border-radius:99px;color:var(--ink-soft);font-weight:600;font-size:.93rem;transition:background .15s,color .15s}
.main-nav a:hover{background:var(--accent-soft);color:var(--accent);text-decoration:none}
.main-nav a.active{color:#fff;background:var(--grad);box-shadow:0 3px 12px rgba(37,99,235,.3)}
.nav-toggle,.theme-toggle{background:transparent;border:1px solid var(--line);border-radius:10px;padding:7px 11px;font-size:1.05rem;cursor:pointer;color:var(--ink-soft);transition:border-color .15s,transform .15s}
.nav-toggle:hover,.theme-toggle:hover{border-color:var(--accent);transform:translateY(-1px)}
.nav-toggle{display:none}
.header-actions{display:flex;align-items:center;gap:8px}
@media(max-width:860px){
  .nav-toggle{display:block}
  .main-nav{display:none;position:absolute;top:64px;left:0;right:0;background:var(--card);flex-direction:column;align-items:stretch;padding:12px 18px 18px;border-bottom:1px solid var(--line);box-shadow:var(--shadow)}
  .main-nav.open{display:flex}
  .main-nav a{padding:13px 16px;border-radius:12px}
}

/* ---------- Hero: gradient mesh + grid ---------- */
.hero{position:relative;overflow:hidden;color:var(--hero-text);padding:64px 0 72px;text-align:center;
  background:#0c1430;
  background-image:
    radial-gradient(ellipse 60% 50% at 18% 8%,rgba(37,99,235,.45),transparent 60%),
    radial-gradient(ellipse 50% 45% at 85% 20%,rgba(124,58,237,.4),transparent 60%),
    radial-gradient(ellipse 70% 60% at 50% 110%,rgba(37,99,235,.25),transparent 65%),
    linear-gradient(rgba(255,255,255,.045) 1px,transparent 1px),
    linear-gradient(90deg,rgba(255,255,255,.045) 1px,transparent 1px);
  background-size:auto,auto,auto,44px 44px,44px 44px;}
.hero h1{font-size:clamp(1.85rem,4.6vw,3rem);letter-spacing:-1.2px;line-height:1.14;margin-bottom:16px;font-weight:700}
.hero h1 .hl{background:linear-gradient(135deg,#7eb0ff,#b69bff);-webkit-background-clip:text;background-clip:text;color:transparent}
.hero p{max-width:700px;margin:0 auto 30px;color:var(--hero-sub);font-size:1.1rem}
.hero .btn{margin:5px 7px}
.badge-row{display:flex;flex-wrap:wrap;gap:10px;justify-content:center;margin-top:32px}
.badge{background:rgba(255,255,255,.08);border:1px solid rgba(255,255,255,.18);padding:7px 15px;border-radius:99px;font-size:.84rem;color:#d6e1ff;backdrop-filter:blur(4px)}

/* ---------- Buttons ---------- */
.btn{display:inline-block;padding:13px 26px;border-radius:12px;font-weight:700;font-size:1rem;border:none;cursor:pointer;font-family:var(--font);letter-spacing:.1px;transition:transform .15s ease,box-shadow .2s,filter .15s}
.btn-primary{background:var(--grad);color:#fff!important;box-shadow:0 6px 18px rgba(53,87,255,.35)}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 10px 26px rgba(53,87,255,.45);text-decoration:none;filter:brightness(1.05)}
.btn-primary:active{transform:translateY(0)}
.btn-ghost{background:rgba(255,255,255,.1);color:#fff!important;border:1px solid rgba(255,255,255,.35);backdrop-filter:blur(4px)}
.btn-ghost:hover{background:rgba(255,255,255,.18);text-decoration:none;transform:translateY(-2px)}
.btn-block{display:block;width:100%}

/* ---------- Sections & cards ---------- */
.section{padding:56px 0}
.section h2{font-size:1.75rem;letter-spacing:-.6px;margin-bottom:8px;color:var(--navy)}
.section .sub{color:var(--ink-faint);margin-bottom:30px;max-width:740px}
.grid{display:grid;gap:20px}
.grid-3{grid-template-columns:repeat(3,1fr)}
.grid-2{grid-template-columns:repeat(2,1fr)}
.grid-4{grid-template-columns:repeat(4,1fr)}
@media(max-width:920px){.grid-3,.grid-4{grid-template-columns:repeat(2,1fr)}}
@media(max-width:600px){.grid-2,.grid-3,.grid-4{grid-template-columns:1fr}}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:24px;box-shadow:var(--shadow);transition:background .3s,border-color .3s}
a.tool-card{display:block;color:inherit;position:relative;transition:transform .18s ease,box-shadow .18s ease,border-color .18s}
a.tool-card:hover{text-decoration:none;transform:translateY(-5px);box-shadow:var(--shadow-lift);border-color:var(--accent)}
a.tool-card::after{content:"";position:absolute;inset:0 auto auto 0;width:100%;height:3px;border-radius:16px 16px 0 0;background:var(--grad);opacity:0;transition:opacity .18s}
a.tool-card:hover::after{opacity:1}
.tool-card .icon{width:48px;height:48px;border-radius:13px;display:flex;align-items:center;justify-content:center;font-size:1.4rem;margin-bottom:15px;background:var(--accent-soft);box-shadow:inset 0 0 0 1px rgba(37,99,235,.12)}
.tool-card h3{font-size:1.07rem;margin-bottom:7px;color:var(--navy);letter-spacing:-.2px}
.tool-card p{font-size:.92rem;color:var(--ink-soft)}
.tool-card .go{display:inline-block;margin-top:12px;font-weight:700;color:var(--accent);font-size:.9rem}

/* ---------- Calculator layout ---------- */
.calc-wrap{display:grid;grid-template-columns:minmax(0,440px) minmax(0,1fr);gap:26px;align-items:start;margin:32px 0 10px}
@media(max-width:900px){.calc-wrap{grid-template-columns:1fr}}
.calc-panel{position:sticky;top:84px;border-top:3px solid transparent;border-image:linear-gradient(135deg,#2563eb,#6d4aff) 1;border-top:3px solid;border-image-slice:1}
@media(max-width:900px){.calc-panel{position:static}}
.field{margin-bottom:17px}
.field label{display:block;font-weight:600;font-size:.92rem;margin-bottom:7px;color:var(--navy)}
.field .hint{font-size:.8rem;color:var(--ink-faint);margin-top:5px;line-height:1.5}
input[type=number],input[type=text],input[type=email],select,textarea{width:100%;padding:12px 14px;border:1.5px solid var(--line);border-radius:var(--radius-sm);font-size:1rem;font-family:var(--font);background:var(--card);color:var(--ink);transition:border-color .15s,box-shadow .15s,background .3s}
input:hover,select:hover{border-color:var(--ink-faint)}
input:focus,select:focus,textarea:focus{outline:none;border-color:var(--accent);box-shadow:0 0 0 4px rgba(37,99,235,.14)}
.input-group{position:relative}
.input-group .prefix{position:absolute;left:14px;top:50%;transform:translateY(-50%);color:var(--ink-faint);font-weight:600}
.input-group input{padding-left:30px}
.input-row{display:grid;grid-template-columns:1fr 1fr;gap:13px}
@media(max-width:480px){.input-row{grid-template-columns:1fr}}

/* ---------- Results ---------- */
.results{min-height:120px}
.result-hero{position:relative;overflow:hidden;background:linear-gradient(135deg,#13203f 0%,#2347a8 70%,#5b3fb8 100%);color:#fff;border-radius:var(--radius);padding:26px;margin-bottom:18px;box-shadow:0 14px 34px rgba(20,40,110,.35)}
.result-hero::before{content:"";position:absolute;top:-60%;right:-20%;width:70%;height:200%;background:radial-gradient(ellipse,rgba(125,160,255,.35),transparent 65%);pointer-events:none}
.result-hero .label{font-size:.84rem;color:#aebfec;text-transform:uppercase;letter-spacing:1.1px;font-weight:600}
.result-hero .big{font-size:2.5rem;font-weight:700;letter-spacing:-1.4px;margin:3px 0 5px}
.result-hero .meta{font-size:.93rem;color:#c8d5f7}
.stat-row{display:grid;grid-template-columns:repeat(auto-fit,minmax(145px,1fr));gap:13px;margin-bottom:18px}
.stat{background:var(--card);border:1px solid var(--line);border-radius:var(--radius-sm);padding:15px;transition:border-color .15s}
.stat:hover{border-color:var(--accent)}
.stat .k{font-size:.74rem;color:var(--ink-faint);text-transform:uppercase;letter-spacing:.7px;font-weight:600}
.stat .v{font-size:1.3rem;font-weight:700;color:var(--navy);font-variant-numeric:tabular-nums;letter-spacing:-.5px}
.stat .v.pos{color:var(--green)}
.stat .v.neg{color:var(--red)}

/* ---------- Tables ---------- */
.table-scroll{overflow-x:auto;-webkit-overflow-scrolling:touch;border-radius:var(--radius-sm)}
table{width:100%;border-collapse:collapse;background:var(--card);border-radius:var(--radius-sm);overflow:hidden;font-size:.94rem;box-shadow:inset 0 0 0 1px var(--line)}
th,td{padding:11px 14px;text-align:left;border-bottom:1px solid var(--line)}
th{background:var(--th-bg);color:var(--th-text);font-weight:600;font-size:.84rem;letter-spacing:.4px;text-transform:uppercase}
tr:last-child td{border-bottom:none}
tbody tr{transition:background .12s}
tbody tr:nth-child(even){background:var(--row-alt)}
tbody tr:hover{background:var(--accent-soft)}
td.num,th.num{text-align:right;font-variant-numeric:tabular-nums}
.bar-bg{background:var(--accent-soft);border-radius:5px;height:9px;min-width:60px}
.bar-fill{background:var(--grad);height:9px;border-radius:5px;box-shadow:0 1px 4px rgba(37,99,235,.4)}

/* ---------- Article ---------- */
.article{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:38px;margin:28px 0;box-shadow:var(--shadow)}
@media(max-width:600px){.article{padding:24px 19px}}
.article h2{font-size:1.5rem;color:var(--navy);margin:34px 0 13px;letter-spacing:-.5px;position:relative;padding-left:16px}
.article h2::before{content:"";position:absolute;left:0;top:.32em;bottom:.22em;width:4px;border-radius:4px;background:var(--grad)}
.article h2:first-child{margin-top:0}
.article h3{font-size:1.14rem;color:var(--navy);margin:24px 0 10px}
.article p{margin-bottom:15px;color:var(--ink-soft)}
.article strong{color:var(--ink)}
.article ul,.article ol{margin:0 0 15px 24px;color:var(--ink-soft)}
.article li{margin-bottom:8px}
.article table{margin:15px 0 22px}
.callout{border-left:4px solid var(--accent);background:var(--accent-soft);padding:15px 19px;border-radius:0 12px 12px 0;margin:20px 0;font-size:.96rem;color:var(--ink)}
.callout.warn{border-color:var(--amber);background:var(--amber-light)}
.callout.good{border-color:var(--green);background:var(--green-light)}
.updated-tag{display:inline-flex;align-items:center;gap:6px;background:var(--green-light);color:var(--green);font-weight:700;font-size:.8rem;padding:6px 14px;border-radius:99px;margin-bottom:15px;border:1px solid rgba(10,157,99,.2)}

/* ---------- FAQ ---------- */
.faq details{background:var(--card);border:1px solid var(--line);border-radius:14px;margin-bottom:11px;overflow:hidden;transition:border-color .15s,box-shadow .15s}
.faq details:hover{border-color:var(--accent)}
.faq details[open]{box-shadow:var(--shadow);border-color:var(--accent)}
.faq summary{padding:16px 20px;font-weight:600;cursor:pointer;color:var(--navy);list-style:none;position:relative;padding-right:46px;font-size:.99rem}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"+";position:absolute;right:19px;top:50%;transform:translateY(-50%);font-size:1.45rem;font-weight:300;color:var(--accent);transition:transform .2s}
.faq details[open] summary::after{transform:translateY(-50%) rotate(45deg)}
.faq .faq-a{padding:0 20px 17px;color:var(--ink-soft);font-size:.95rem}

/* ---------- Page head / breadcrumbs ---------- */
.page-head{padding:34px 0 8px}
.breadcrumb{font-size:.84rem;color:var(--ink-faint);margin-bottom:14px}
.breadcrumb a{color:var(--ink-faint)}
.breadcrumb a:hover{color:var(--accent)}
.page-head h1{font-size:clamp(1.55rem,3.6vw,2.3rem);color:var(--navy);letter-spacing:-.8px;line-height:1.22;margin-bottom:11px}
.page-head .lede{color:var(--ink-soft);max-width:780px;font-size:1.06rem}
.related{margin:38px 0}
.related h2{font-size:1.35rem;color:var(--navy);margin-bottom:18px;letter-spacing:-.4px}
.ad-slot{margin:26px auto;text-align:center;min-height:0}

/* ---------- Footer ---------- */
.site-footer{background:#0c1430;color:#9fb0d8;margin-top:64px;padding:50px 0 32px;font-size:.93rem;
  background-image:radial-gradient(ellipse 50% 60% at 90% 0%,rgba(124,58,237,.15),transparent 60%)}
.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr 1fr;gap:32px;margin-bottom:32px}
@media(max-width:800px){.footer-grid{grid-template-columns:1fr 1fr}}
@media(max-width:500px){.footer-grid{grid-template-columns:1fr}}
.site-footer h4{color:#fff;font-size:.92rem;margin-bottom:13px;letter-spacing:.3px;text-transform:uppercase;font-family:var(--display)}
.site-footer a{color:#9fb0d8;display:block;margin-bottom:9px;transition:color .12s}
.site-footer a:hover{color:#fff;text-decoration:none}
.footer-brand{font-weight:700;font-size:1.2rem;color:#fff;margin-bottom:11px;font-family:var(--display)}
.footer-disclaimer{border-top:1px solid rgba(255,255,255,.1);padding-top:22px;font-size:.79rem;color:#6f7fa6;line-height:1.65}

/* ---------- Motion & misc ---------- */
@keyframes rise{from{opacity:0;transform:translateY(14px)}to{opacity:1;transform:none}}
.tool-card,.result-hero,.stat{animation:rise .45s cubic-bezier(.2,.7,.3,1) both}
.tool-card:nth-child(2){animation-delay:.04s}.tool-card:nth-child(3){animation-delay:.08s}.tool-card:nth-child(4){animation-delay:.12s}
.tool-card:nth-child(5){animation-delay:.16s}.tool-card:nth-child(6){animation-delay:.2s}.tool-card:nth-child(7){animation-delay:.24s}.tool-card:nth-child(8){animation-delay:.28s}
@media(prefers-reduced-motion:reduce){*,*::before,*::after{animation:none!important;transition:none!important}html{scroll-behavior:auto}}
::-webkit-scrollbar{width:11px;height:11px}
::-webkit-scrollbar-track{background:var(--bg)}
::-webkit-scrollbar-thumb{background:var(--ink-faint);border-radius:8px;border:3px solid var(--bg)}
::-webkit-scrollbar-thumb:hover{background:var(--accent)}
.print-btn{background:none;border:1px solid var(--line);border-radius:10px;padding:8px 14px;font-size:.88rem;cursor:pointer;color:var(--ink-soft);font-weight:600}
.print-btn:hover{border-color:var(--accent);color:var(--accent)}
@media print{.site-header,.site-footer,.calc-panel form button,.related,.faq,.ad-slot,.nav-toggle,.theme-toggle,.print-btn{display:none!important}body{background:#fff}.card,.article{box-shadow:none;border:none}}