@import url('https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@400;500;600;700&family=Manrope:wght@400;500;600;700;800&family=JetBrains+Mono:wght@400;500;600&display=swap');
*{margin:0;padding:0;box-sizing:border-box}
:root{
  --ink:#070b11;--ink2:#0b121d;--panel:#0e1722;--panel2:#13202f;--line:#1d2c3d;--line2:#273a4f;
  --txt:#eaf0f6;--txt2:#aab8c6;--muted:#6c7d8e;
  --emer:#34d399;--cyan:#22d3ee;--violet:#8b5cf6;--gold:#e8b53e;
  --emerSoft:#0f2620;--goldSoft:#241d10;--redSoft:#2a1414;--red:#f06d6d;
  --aurora:linear-gradient(120deg,#34d399 0%,#22d3ee 38%,#8b5cf6 78%);
  --glow:0 0 0 1px rgba(52,211,153,.12),0 18px 60px -18px rgba(34,211,238,.35);
  --r:16px;--maxw:1080px;
}
html{scroll-behavior:smooth}
body{font-family:'Manrope',system-ui,sans-serif;background:var(--ink);color:var(--txt);line-height:1.55;-webkit-font-smoothing:antialiased;overflow-x:hidden;min-height:100vh}
a{color:inherit;text-decoration:none}
.mono,input[type=number]{font-family:'JetBrains Mono',monospace;font-variant-numeric:tabular-nums}

/* ambient background */
#aurora{position:fixed;inset:0;z-index:-2;opacity:.85}
.grid-bg{position:fixed;inset:0;z-index:-1;pointer-events:none;
  background-image:linear-gradient(rgba(52,211,153,.04) 1px,transparent 1px),linear-gradient(90deg,rgba(52,211,153,.04) 1px,transparent 1px);
  background-size:64px 64px;-webkit-mask-image:radial-gradient(ellipse 90% 55% at 50% 0%,#000 30%,transparent 80%);mask-image:radial-gradient(ellipse 90% 55% at 50% 0%,#000 30%,transparent 80%)}

/* header (matches aitaxtips.com) */
header.nav{position:sticky;top:0;z-index:50;backdrop-filter:blur(16px);background:rgba(7,11,17,.62);border-bottom:1px solid var(--line)}
.nav-in{max-width:1180px;margin:0 auto;height:70px;display:flex;align-items:center;gap:26px;padding:0 24px}
.brand{display:flex;align-items:center;gap:11px;font-family:'Space Grotesk';font-weight:700;font-size:19px;letter-spacing:-.01em}
.brand .mark{width:34px;height:34px;border-radius:10px;position:relative;background:var(--aurora);display:grid;place-items:center;box-shadow:0 0 18px rgba(52,211,153,.5);overflow:hidden}
.brand .mark::after{content:'';position:absolute;inset:1.5px;border-radius:8px;background:var(--ink)}
.brand .mark span{position:relative;z-index:1;font-size:15px;font-weight:700;background:var(--aurora);-webkit-background-clip:text;background-clip:text;color:transparent}
.brand em{font-style:normal;background:var(--aurora);-webkit-background-clip:text;background-clip:text;color:transparent}
.nav-links{display:flex;gap:6px;margin-left:14px}
.nav-links a{font-size:14.5px;font-weight:600;color:var(--txt2);padding:9px 14px;border-radius:10px;transition:.18s}
.nav-links a:hover,.nav-links a.active{color:var(--txt);background:rgba(52,211,153,.08)}
.nav-cta{margin-left:auto;display:flex;align-items:center;gap:12px}
.btn{font-family:'Manrope';font-weight:700;font-size:14.5px;border:none;cursor:pointer;border-radius:11px;padding:11px 20px;transition:.18s;display:inline-flex;align-items:center;gap:8px}
.btn-primary{background:var(--aurora);color:#04130d;box-shadow:0 8px 30px -8px rgba(34,211,238,.6)}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 14px 40px -10px rgba(34,211,238,.75)}
.menu-btn{display:none;margin-left:auto;background:none;border:1px solid var(--line2);border-radius:10px;width:42px;height:42px;color:var(--txt);font-size:18px;cursor:pointer}
.mobile-menu{display:none;flex-direction:column;gap:4px;padding:10px 24px 18px;border-bottom:1px solid var(--line);background:rgba(7,11,17,.96)}
.mobile-menu a{padding:13px 14px;border-radius:10px;font-weight:600;color:var(--txt2)}
.mobile-menu a:hover{background:rgba(52,211,153,.08);color:var(--txt)}
.mobile-menu .btn{margin-top:8px;justify-content:center}

/* calculator page */
.fk-wrap{max-width:var(--maxw);margin:0 auto;padding:40px 24px 30px;animation:fade .6s cubic-bezier(.2,.7,.2,1)}
@keyframes fade{from{opacity:0;transform:translateY(14px)}to{opacity:1;transform:none}}
.fk-cat{display:inline-flex;align-items:center;font-family:'JetBrains Mono';font-size:11px;letter-spacing:.18em;text-transform:uppercase;color:var(--emer);background:var(--emerSoft);border:1px solid #1c4435;padding:5px 12px;border-radius:30px}
.fk-title{font-family:'Space Grotesk';font-weight:600;font-size:clamp(30px,5vw,46px);letter-spacing:-.025em;line-height:1.05;margin:16px 0 10px}
.fk-tagline{color:var(--txt2);font-size:17px;max-width:62ch;margin-bottom:28px}

.grid2{display:grid;grid-template-columns:1fr 1fr;gap:18px}
.panel{background:linear-gradient(180deg,rgba(19,32,47,.6),rgba(11,18,29,.6));border:1px solid var(--line);border-radius:var(--r);padding:24px}
.panel.out{background:linear-gradient(180deg,rgba(14,23,34,.7),rgba(8,13,20,.7))}
.panel-h{font-family:'Space Grotesk';font-size:18px;font-weight:600;margin-bottom:16px}

/* form */
.form-head{font-family:'JetBrains Mono';font-size:10.5px;letter-spacing:.16em;text-transform:uppercase;color:var(--muted);margin:16px 0 10px;padding-bottom:6px;border-bottom:1px solid var(--line)}
.field{margin-bottom:14px}
.field label{display:flex;justify-content:space-between;align-items:center;font-size:13px;font-weight:600;color:var(--txt2);margin-bottom:6px}
.ref{font-family:'JetBrains Mono';font-size:10px;color:var(--emer);background:var(--emerSoft);padding:2px 8px;border-radius:14px;font-weight:500}
input,select{width:100%;font-family:inherit;font-size:14.5px;color:var(--txt);background:var(--ink2);border:1px solid var(--line2);border-radius:10px;padding:11px 13px;transition:.16s}
input:focus,select:focus{outline:none;border-color:var(--emer);box-shadow:0 0 0 3px rgba(52,211,153,.14)}
.inr-wrap{position:relative}
.inr-wrap::before{content:'\20B9';position:absolute;left:12px;top:50%;transform:translateY(-50%);color:var(--muted);font-family:'JetBrains Mono';font-size:13px}
.inr-wrap input{padding-left:25px}
.hint{font-size:11px;color:var(--muted);margin-top:5px;display:block;line-height:1.5}
.seg{display:flex;background:var(--ink2);border:1px solid var(--line2);border-radius:10px;padding:3px}
.seg button{flex:1;background:none;border:none;color:var(--txt2);font-family:inherit;font-weight:600;font-size:13px;padding:9px;border-radius:7px;cursor:pointer;transition:.16s}
.seg button.on{background:var(--aurora);color:#04130d}

/* output */
.big{margin-bottom:16px}
.big-l{font-size:11px;letter-spacing:.13em;text-transform:uppercase;color:var(--muted);font-weight:600;margin-bottom:7px}
.big-v{font-family:'JetBrains Mono';font-size:38px;font-weight:600;letter-spacing:-.02em;line-height:1;background:var(--aurora);-webkit-background-clip:text;background-clip:text;color:transparent}
.big-s{font-size:13px;color:var(--txt2);margin-top:7px}
.cmp{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin-bottom:16px}
.cmp .c{border:1px solid var(--line);border-radius:12px;padding:14px 15px;position:relative;background:rgba(255,255,255,.015)}
.cmp .c.win{border-color:var(--emer);box-shadow:0 0 0 1px var(--emer),0 0 26px -8px rgba(52,211,153,.5)}
.cmp .c-n{font-size:10.5px;color:var(--muted);text-transform:uppercase;letter-spacing:.1em;font-weight:600}
.cmp .c-a{font-family:'JetBrains Mono';font-size:21px;font-weight:600;margin-top:5px}
.cmp .w{position:absolute;top:-9px;right:10px;font-size:9px;background:var(--aurora);color:#04130d;padding:3px 9px;border-radius:12px;font-weight:700;letter-spacing:.05em}
.brk{border-top:1px dashed var(--line);padding-top:12px}
.brk .l{display:flex;justify-content:space-between;font-size:13px;padding:5px 0;color:var(--txt2);gap:14px}
.brk .l span:last-child{font-family:'JetBrains Mono';white-space:nowrap}
.brk .l.tot{font-weight:700;color:var(--txt);border-top:1px solid var(--line);margin-top:6px;padding-top:9px}
.note{font-size:12.5px;color:var(--txt2);background:var(--emerSoft);border-left:3px solid var(--emer);border-radius:0 9px 9px 0;padding:11px 14px;margin-top:14px;line-height:1.55}
.note b{color:var(--txt)}
.exp{display:flex;gap:8px;margin-top:20px}
.exp button{flex:1;background:rgba(255,255,255,.03);border:1px solid var(--line2);color:var(--txt2);font-family:inherit;font-weight:700;font-size:12.5px;padding:10px;border-radius:10px;cursor:pointer;transition:.16s}
.exp button:hover{border-color:var(--emer);color:var(--emer);transform:translateY(-1px)}

/* advisory */
#fk-advisory,#fk-legal{margin-top:18px}
.adv-group{margin-bottom:16px}
.adv-group-h{font-family:'JetBrains Mono';font-size:10.5px;letter-spacing:.14em;text-transform:uppercase;color:var(--muted);margin-bottom:9px}
.adv{display:flex;gap:12px;align-items:flex-start;background:rgba(19,32,47,.55);border:1px solid var(--line);border-left:3px solid var(--muted);border-radius:11px;padding:13px 16px;margin-bottom:9px;transition:.16s}
.adv:hover{border-color:var(--line2)}
.adv.ok{border-left-color:var(--emer)}.adv.tip{border-left-color:var(--gold)}.adv.warn{border-left-color:var(--red);background:var(--redSoft)}
.adv-ic{flex:0 0 auto;width:24px;height:24px;border-radius:7px;display:grid;place-items:center;font-size:12px;font-weight:700;font-family:'JetBrains Mono';background:var(--emerSoft);color:var(--emer)}
.adv.tip .adv-ic{background:var(--goldSoft);color:var(--gold)}.adv.warn .adv-ic{background:#3a1c1c;color:var(--red)}
.adv-t{font-weight:600;font-size:13.5px}.adv-d{font-size:12.5px;color:var(--txt2);margin-top:3px;line-height:1.5}
.adv-ref{display:inline-block;margin-top:7px;font-family:'JetBrains Mono';font-size:10px;color:var(--emer);background:var(--emerSoft);padding:2px 8px;border-radius:14px}

/* legal */
.legal-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:12px}
.legal-card{background:rgba(19,32,47,.55);border:1px solid var(--line);border-radius:12px;padding:15px;transition:.16s}
.legal-card:hover{border-color:var(--line2)}
.legal-law{font-size:11px;color:var(--muted);text-transform:uppercase;letter-spacing:.08em;font-weight:600}
.legal-sec{font-family:'Space Grotesk';font-size:16px;font-weight:600;color:var(--emer);margin:4px 0 8px}
.legal-row{display:flex;justify-content:space-between;font-size:11.5px;color:var(--txt2);padding:2px 0;gap:10px}
.legal-row span:first-child{color:var(--muted)}
.legal-note{font-size:11.5px;color:var(--txt2);margin-top:8px;line-height:1.5}

/* faq + disclaimer */
.faq{border-top:1px solid var(--line);padding:12px 0}
.faq summary{cursor:pointer;font-weight:600;font-size:14px;list-style:none;display:flex;gap:8px}
.faq summary::before{content:'+';color:var(--emer);font-family:'JetBrains Mono';font-weight:700}
.faq[open] summary::before{content:'\2212'}
.faq p{font-size:13px;color:var(--txt2);margin-top:9px;padding-left:18px}
.disclaimer{font-size:12px;color:var(--muted);background:var(--goldSoft);border:1px solid #4a3a18;border-radius:12px;padding:14px 16px;margin:18px 0;line-height:1.6}
.disclaimer b{color:var(--gold)}

/* footer (matches aitaxtips.com) */
footer{border-top:1px solid var(--line);margin-top:30px;background:rgba(7,11,17,.6)}
.foot-in{max-width:1180px;margin:0 auto;padding:54px 24px 28px;display:grid;grid-template-columns:1.6fr 1fr 1fr 1fr;gap:40px}
.foot-brand p{color:var(--txt2);font-size:14px;margin-top:14px;max-width:34ch}
.foot-col h5{font-family:'JetBrains Mono';font-size:11px;letter-spacing:.16em;text-transform:uppercase;color:var(--muted);margin-bottom:14px}
.foot-col a{display:block;color:var(--txt2);font-size:14px;padding:5px 0;transition:.15s}
.foot-col a:hover{color:var(--emer)}
.foot-bottom{border-top:1px solid var(--line);padding:22px 24px;max-width:1180px;margin:0 auto;display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap;font-size:12.5px;color:var(--muted)}

/* responsive */
@media(max-width:820px){
  .grid2{grid-template-columns:1fr}
  .nav-links,.nav-cta .btn{display:none}.menu-btn{display:block}
  .foot-in{grid-template-columns:1fr 1fr;gap:28px}
}
@media(max-width:520px){.foot-in{grid-template-columns:1fr}.cmp{grid-template-columns:1fr}}
@media(prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important}}