*{box-sizing:border-box;margin:0;padding:0}
:root{--bg:#f4f6fb;--card:#fff;--ink:#0f1e3d;--muted:#5b6b82;--navy:#0b2b4e;--navy2:#143d6b;--brand:#2f5bff;--brand-d:#1e40d8;--gold:#f5c518;--gold-soft:#fff7d9;--ok:#16a34a;--err:#dc2626;--line:#e4e9f2}
body{font-family:'Inter','Segoe UI',system-ui,-apple-system,Arial,sans-serif;background:var(--bg);color:var(--ink);line-height:1.65;-webkit-font-smoothing:antialiased}
h1,h2,h3,.logo,.btn,.hero-stats .st b{font-family:'Poppins','Inter',system-ui,sans-serif}
::selection{background:#dbe4ff}
.wrap{max-width:1140px;margin:0 auto;padding:0 20px}
header.top{background:#fff;position:sticky;top:0;z-index:50;box-shadow:0 2px 12px rgba(11,43,78,.08);border-bottom:1px solid var(--line)}
.top-in{display:flex;align-items:center;gap:14px;padding:13px 0}
.logo{font-weight:800;font-size:1.35rem;color:var(--navy);text-decoration:none;letter-spacing:-.02em}
.logo .dot{color:var(--gold)}
nav.main{display:flex;gap:2px;flex-wrap:wrap;margin-left:auto}
nav.main a{padding:8px 13px;border-radius:999px;color:var(--muted);text-decoration:none;font-size:.93rem;font-weight:600}
nav.main a:hover{background:#eaf0ff;color:var(--brand)}
/* ---------- home hero ---------- */
.hero-wash{background:linear-gradient(135deg,#0b2b4e 0%,#123c6b 55%,#1a4d86 100%);padding:84px 0 72px;text-align:center;position:relative;overflow:hidden;color:#fff}
.hero-wash::before{content:'';position:absolute;width:560px;height:560px;right:-160px;top:-200px;background:radial-gradient(circle,rgba(245,197,24,.16),transparent 65%)}
.hero-wash::after{content:'';position:absolute;width:520px;height:520px;left:-180px;bottom:-240px;background:radial-gradient(circle,rgba(47,91,255,.28),transparent 65%)}
.hero-wash h1{font-size:2.8rem;letter-spacing:-.03em;line-height:1.15;margin-bottom:14px;position:relative;color:#fff}
.hero-wash h1 .hl{color:var(--gold)}
.hero-wash p{color:#c9d6ea;font-size:1.12rem;max-width:640px;margin:0 auto 28px;position:relative}
.search{max-width:560px;margin:0 auto;display:flex;position:relative;background:#fff;border:none;border-radius:999px;padding:6px;box-shadow:0 14px 36px rgba(0,0,0,.28);transition:.2s}
.search input{flex:1;padding:12px 20px;border:none;border-radius:999px;font-size:1rem;outline:none;background:transparent;font-family:inherit}
.search button{padding:12px 28px;border:none;border-radius:999px;background:var(--brand);color:#fff;font-size:1rem;font-weight:700;cursor:pointer;transition:.18s;font-family:inherit}
.search button:hover{background:var(--brand-d)}
.trust{display:inline-flex;gap:8px;align-items:center;margin-top:24px;border:1.5px solid rgba(245,197,24,.55);color:var(--gold);border-radius:999px;padding:9px 20px;font-size:.88rem;font-weight:600;position:relative;background:rgba(245,197,24,.07)}
.hero-stats{display:flex;gap:40px;justify-content:center;margin-top:26px;position:relative;flex-wrap:wrap}
.hero-stats .st{text-align:center}
.hero-stats .st b{font-size:1.6rem;letter-spacing:-.02em;display:block;color:#fff}
.hero-stats .st span{font-size:.85rem;color:#a9bedd}
section{padding:44px 0}
h2.sec{font-size:1.6rem;margin-bottom:6px;letter-spacing:-.02em}
.sec-sub{color:var(--muted);margin-bottom:24px}
/* ---------- category cards ---------- */
.cat-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(160px,1fr));gap:16px}
.cat-card{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:24px 16px;text-decoration:none;color:var(--ink);transition:.2s;display:flex;flex-direction:column;align-items:center;gap:12px;text-align:center;box-shadow:0 2px 8px rgba(15,30,61,.04)}
.cat-card:hover{border-color:var(--brand);transform:translateY(-4px);box-shadow:0 16px 32px rgba(47,91,255,.14)}
.cat-ic{width:56px;height:56px;border-radius:16px;background:#eaf0ff;color:var(--brand);display:flex;align-items:center;justify-content:center}
.cat-ic svg{width:28px;height:28px}
.cat-card h3{font-size:1rem;letter-spacing:-.01em}
.cat-card .cnt{font-size:.82rem;color:var(--muted)}
/* ---------- calculator cards ---------- */
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:18px}
.card{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:22px;text-decoration:none;color:var(--ink);transition:.2s;display:flex;flex-direction:column;gap:8px;box-shadow:0 2px 8px rgba(15,30,61,.04)}
a.card:hover{border-color:var(--brand);transform:translateY(-4px);box-shadow:0 16px 32px rgba(47,91,255,.14)}
.card h3{font-size:1.05rem;letter-spacing:-.01em;display:flex;align-items:center;justify-content:space-between}
.card h3 .arr{color:var(--brand);font-weight:400;transition:.2s}
a.card:hover h3 .arr{transform:translateX(4px)}
.card p{font-size:.9rem;color:var(--muted);flex:1}
.card .cat{font-size:.78rem;color:var(--muted);font-weight:600;text-transform:uppercase;letter-spacing:.08em}
/* ---------- feature strip ---------- */
.feat{background:#fff;border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
.feat-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:28px;padding:8px 0}
.feat-it{display:flex;gap:14px;align-items:flex-start}
.feat-it .fi{width:46px;height:46px;flex:none;border-radius:14px;background:#eaf0ff;color:var(--brand);display:flex;align-items:center;justify-content:center;font-size:1.25rem}
.feat-it h4{font-size:.98rem;margin-bottom:4px}
.feat-it p{font-size:.87rem;color:var(--muted);margin:0}
.page-hero{background:linear-gradient(135deg,#0b2b4e 0%,#143d6b 70%,#1a4d86 100%);padding:46px 0 96px;position:relative;overflow:hidden;color:#fff}
.page-hero::after{content:'';position:absolute;width:480px;height:480px;right:-140px;top:-220px;background:radial-gradient(circle,rgba(245,197,24,.13),transparent 65%)}
.page-hero h1{font-size:2.2rem;margin:10px 0 10px;letter-spacing:-.025em;position:relative;color:#fff}
.page-hero p{color:#c9d6ea;max-width:720px;position:relative}
.page-hero .crumbs{margin:0 0 4px;position:relative;color:#a9bedd}
.page-hero .crumbs a{color:var(--gold)}
.calc-shell{background:var(--card);border:1px solid var(--line);border-radius:20px;padding:34px;margin:-64px 0 26px;position:relative;box-shadow:0 20px 48px rgba(11,43,78,.12)}
.badge{display:inline-block;background:var(--gold-soft);color:#8a6d00;font-size:.72rem;font-weight:800;letter-spacing:1.5px;padding:6px 14px;border-radius:999px;margin-bottom:18px}
.field{margin-bottom:18px}
.field label{display:block;font-weight:700;margin-bottom:7px;font-size:.95rem}
.field input,.field select,.field textarea{width:100%;padding:14px 15px;border:1.5px solid var(--line);border-radius:12px;font-size:1.02rem;background:#fbfcfe;transition:.15s;font-family:inherit}
.field input:focus,.field select:focus,.field textarea:focus{outline:none;border-color:var(--brand);background:#fff;box-shadow:0 0 0 4px rgba(47,91,255,.12)}
.field .hint{font-size:.8rem;color:var(--muted);margin-top:4px}
.btn{background:var(--brand);color:#fff;border:none;padding:16px 36px;border-radius:14px;font-size:1.05rem;font-weight:700;cursor:pointer;box-shadow:0 10px 24px rgba(47,91,255,.35);transition:.18s;font-family:inherit}
.btn:hover{background:var(--brand-d);transform:translateY(-2px);box-shadow:0 14px 30px rgba(47,91,255,.42)}
.btn:active{transform:translateY(0)}
.results{background:linear-gradient(180deg,#102f57,#0b2b4e);border:none;border-radius:16px;padding:26px;color:#fff;box-shadow:0 14px 30px rgba(11,43,78,.3)}
.results.show{animation:fadeUp .35s ease}
.res-empty{text-align:center;color:#9fb4d4;padding:44px 12px}
.res-empty .big{font-size:2.4rem;margin-bottom:10px}
.res-empty p{margin:0;font-size:.95rem}
.calc-form{min-width:0}
@media(min-width:900px){
.calc-shell{display:grid;grid-template-columns:1fr 1fr;gap:36px;align-items:start}
.calc-shell .badge{grid-column:1/-1;margin-bottom:2px;justify-self:start}
}
@keyframes fadeUp{from{opacity:0;transform:translateY(10px)}to{opacity:1;transform:none}}
.res-hero{text-align:center;padding:8px 0 18px;border-bottom:1px dashed rgba(255,255,255,.18);margin-bottom:6px}
.res-hero-label{font-size:.85rem;font-weight:700;letter-spacing:1.5px;text-transform:uppercase;color:#9fb4d4}
.res-hero-value{font-size:2.7rem;font-weight:800;color:#fff;line-height:1.2;font-variant-numeric:tabular-nums;letter-spacing:-.02em}
.res-hero-value span{font-size:1.35rem;color:var(--gold);font-weight:700}
.res-flex{display:flex;gap:28px;align-items:center;justify-content:center;padding:18px 0 6px;flex-wrap:wrap}
.donut{width:170px;height:170px;flex:none}
.legend{display:flex;flex-direction:column;gap:12px;min-width:210px}
.leg{display:flex;align-items:center;gap:10px;font-size:.95rem;color:#dbe6f5}
.leg .dot{width:14px;height:14px;border-radius:4px;flex:none}
.res-rows{margin-top:8px}
.res-row{display:flex;justify-content:space-between;align-items:center;gap:8px;padding:11px 2px;border-bottom:1px dashed rgba(255,255,255,.14)}
.res-row:last-child{border:none}
.res-row .k{color:#9fb4d4;font-weight:600}
.res-row .v{font-weight:800;font-size:1.2rem;color:#fff;font-variant-numeric:tabular-nums}
.leg .amt{margin-left:auto;font-weight:800;color:#fff;font-variant-numeric:tabular-nums}
.copy{background:rgba(255,255,255,.1);border:1px solid rgba(255,255,255,.22);color:#fff;border-radius:8px;padding:5px 10px;font-size:.74rem;font-weight:700;cursor:pointer;flex:none;transition:.15s;font-family:inherit}
.copy:hover{background:rgba(255,255,255,.22)}
.err{color:var(--err);font-size:.9rem;margin-top:8px;display:none}
.crumbs{font-size:.85rem;color:var(--muted);margin:18px 0 4px}
.crumbs a{color:var(--brand);text-decoration:none}
.article{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:30px;margin:24px 0;box-shadow:0 2px 10px rgba(11,43,78,.05)}
.article h2{font-size:1.32rem;margin:28px 0 10px;padding-left:13px;border-left:4px solid var(--gold)}
.article h2:first-child{margin-top:0;border:none;padding-left:0}
.article p,.article li{color:#33415c;margin-bottom:10px}
.article ul{margin:8px 0 12px 22px}
.formula{background:linear-gradient(135deg,#0b2b4e,#143d6b);color:var(--gold);padding:20px 22px;border-radius:12px;font-family:Consolas,'Courier New',monospace;font-size:1.1rem;margin:14px 0;overflow-x:auto;text-align:center;box-shadow:0 4px 14px rgba(11,43,78,.25)}
.faq{background:#fff;border:1px solid var(--line);border-radius:12px;margin:12px 0;overflow:hidden;transition:border-color .18s,box-shadow .18s}
.faq.open{border-color:#b9c9f5;box-shadow:0 10px 24px rgba(47,91,255,.1)}
.faq-q{width:100%;display:flex;align-items:center;justify-content:space-between;gap:14px;background:none;border:none;padding:18px 20px;font-size:1.02rem;font-weight:700;color:var(--ink);cursor:pointer;text-align:left;font-family:inherit;line-height:1.5}
.faq-q:hover{color:var(--brand)}
.faq-q:focus-visible{outline:2px solid var(--brand);outline-offset:-2px}
.faq-ic{position:relative;width:18px;height:18px;flex:none}
.faq-ic::before,.faq-ic::after{content:'';position:absolute;background:var(--brand);border-radius:2px;transition:transform .25s,opacity .25s}
.faq-ic::before{left:0;right:0;top:8px;height:2px}
.faq-ic::after{top:0;bottom:0;left:8px;width:2px}
.faq.open .faq-ic::after{transform:rotate(90deg);opacity:0}
.faq-a{max-height:none}
html.js .faq-a{max-height:0;overflow:hidden;transition:max-height .32s ease}
.faq-a p{color:#33415c;font-size:.95rem;margin:0;padding:0 20px 20px}
table.data{width:100%;border-collapse:collapse;margin:14px 0;font-size:.92rem;display:block;overflow-x:auto}
table.data th,table.data td{padding:10px 12px;border:1px solid var(--line);text-align:left;white-space:nowrap}
table.data th{background:#eaf0ff;color:var(--brand-d)}
table.data tr:nth-child(even){background:#f8fafc}
footer{margin-top:44px;background:var(--navy);color:#9fb4d4;padding:38px 0;font-size:.9rem}
footer a{color:#dbe6f5;text-decoration:none;margin-right:16px}
footer a:hover{color:var(--gold)}
.badge{display:inline-block;background:#e0f2fe;color:#0369a1;font-size:.75rem;font-weight:700;padding:3px 10px;border-radius:20px;margin-bottom:10px}
/* light home hero, goodcalculators-style: mascot left, tiles right */
.hero-wash{background:#edf0f7;color:var(--ink)}
.hero-wash::before,.hero-wash::after{display:none}
.hero-layout{display:grid;grid-template-columns:minmax(260px,340px) 1fr;gap:40px;align-items:center;text-align:left;position:relative}
.hero-art{display:flex;justify-content:center}
.hero-wash h1{font-size:2rem;color:var(--navy);text-align:left}
.hero-wash h1 .hl{color:var(--brand)}
.hero-wash p{color:var(--muted);font-size:1rem;max-width:560px;margin:0 0 18px;text-align:left}
.hero-wash .search{margin:0;max-width:460px;box-shadow:0 10px 26px rgba(11,43,78,.12)}
.tile-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:12px;margin-top:22px}
.tile{background:#fff;border:1px solid var(--line);border-radius:12px;padding:14px 8px;text-decoration:none;color:var(--ink);transition:.18s;display:flex;flex-direction:column;align-items:center;gap:8px;text-align:center}
.tile:hover{border-color:var(--brand);transform:translateY(-3px);box-shadow:0 12px 24px rgba(47,91,255,.14)}
.t-ic{width:56px;height:56px;border-radius:14px;display:flex;align-items:center;justify-content:center}
.t-ic svg{width:30px;height:30px}
.tile h3{font-size:.85rem;font-weight:700;color:#1d4ed8}
.tile:hover h3{text-decoration:underline}
.tile .cnt{font-size:.7rem;color:var(--muted)}
.stat-band{background:#fff;border-bottom:1px solid var(--line);padding:13px 0;font-size:.9rem;color:var(--muted)}
.stat-band .wrap{display:flex;gap:14px;justify-content:center;align-items:center;flex-wrap:wrap}
.stat-band b{color:var(--navy)}
.stat-band .sep{color:#c3ccd9}
@media(max-width:860px){
.hero-layout{grid-template-columns:1fr;text-align:center}
.hero-art{max-width:280px;margin:0 auto}
.hero-wash h1,.hero-wash p{text-align:center}
.hero-wash p{margin:0 auto 18px}
.hero-wash .search{margin:0 auto}
.tile-grid{grid-template-columns:repeat(3,1fr)}
}
/* real scientific calculator widget */
.sci-calc{background:#fff;border:1px solid var(--line);border-radius:18px;padding:18px;box-shadow:0 20px 44px rgba(11,43,78,.14);max-width:440px;width:100%}
.sci-top{display:flex;justify-content:space-between;align-items:center;margin-bottom:10px}
.sci-brand{font-size:.72rem;font-weight:800;color:var(--muted);letter-spacing:.1em}
.sci-mode{display:flex;background:#eef1f7;border-radius:999px;padding:3px}
.sci-mode button{border:none;background:none;padding:5px 13px;border-radius:999px;font-size:.74rem;font-weight:700;color:var(--muted);cursor:pointer;font-family:inherit}
.sci-mode button.on{background:#fff;color:var(--navy);box-shadow:0 1px 4px rgba(0,0,0,.14)}
.sci-hist{min-height:22px;font-size:.82rem;color:var(--muted);text-align:right;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-family:Consolas,'Courier New',monospace}
.sci-display{background:var(--navy);color:#fff;font-family:Consolas,'Courier New',monospace;font-size:2rem;text-align:right;padding:14px 16px;border-radius:12px;margin-bottom:12px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;min-height:66px}
.sci-grid{display:grid;grid-template-columns:repeat(6,1fr);gap:7px}
.sci-btn{border:1px solid var(--line);background:#f7f9fc;border-radius:9px;padding:11px 2px;font-size:.84rem;font-weight:700;color:var(--navy);cursor:pointer;font-family:inherit;transition:.12s;min-width:0}
.sci-btn:hover{background:#eaf0ff;border-color:#b9c9f5}
.sci-btn.fn{background:#eaf0ff;color:var(--brand-d)}
.sci-btn.op{background:#dbe6ff;color:var(--brand-d);font-size:1rem}
.sci-btn.eq{background:var(--brand);color:#fff;border-color:var(--brand);font-size:1.05rem}
.sci-btn.eq:hover{background:var(--brand-d)}
.sci-btn.clr{background:#fde8e8;color:#dc2626;border-color:#f3c2c2}
.sci-btn.mem{background:#eef1f7;color:#475569;font-size:.76rem}
.sci-btn.d{background:#fff}
@media(max-width:640px){
.hero-wash{padding:56px 0}
.hero-wash h1{font-size:1.9rem}
.calc-shell{padding:20px 16px;margin:18px -6px;border-radius:12px}
.btn{width:100%;padding:15px;font-size:1.1rem}
.field input,.field select,.field textarea{font-size:16px;padding:13px}
.res-row .v{font-size:1.25rem}
.article{padding:20px 16px}
.formula{font-size:1rem;padding:16px 12px}
.crumbs{font-size:.78rem}
.trust{font-size:.78rem;padding:8px 14px}
}