:root{--bg:#f7f8fc;--card:#fff;--card2:#f0f3f8;--text:#111827;--muted:#667085;--line:#e2e7ef;--primary:#635bff;--primary2:#8b5cf6;--soft:#efefff;--shadow:0 12px 38px rgba(21,31,55,.08)}
[data-theme="dark"]{--bg:#0d1118;--card:#151b24;--card2:#1c2430;--text:#f7f8fb;--muted:#a5afbf;--line:#2b3544;--primary:#8b87ff;--primary2:#a78bfa;--soft:#242541;--shadow:0 14px 42px rgba(0,0,0,.24)}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:var(--bg);color:var(--text);font:15px/1.55 Inter,ui-sans-serif,system-ui,-apple-system,"Segoe UI",sans-serif}button,input,select,textarea{font:inherit}button{cursor:pointer}a{text-decoration:none;color:inherit}.hidden{display:none!important}
.site-header{height:74px;max-width:1200px;margin:auto;padding:0 22px;display:flex;align-items:center;justify-content:space-between}.brand{display:flex;align-items:center;gap:11px}.brand-logo{width:46px;height:46px;display:block;flex:0 0 auto}.brand-text strong{display:block;font-size:18px;line-height:1.05}.brand-text small{display:block;color:var(--muted);font-size:10px;letter-spacing:.055em;margin-top:3px}.header-actions{display:flex;gap:8px}.header-link,.theme-btn{height:42px;border:1px solid var(--line);border-radius:12px;background:var(--card);color:var(--text);padding:0 14px}.header-link{font-weight:750}.theme-btn{width:42px;padding:0;font-size:19px}
main{max-width:1200px;margin:auto;padding:0 22px 52px}.hero{display:grid;grid-template-columns:minmax(0,1.05fr) minmax(330px,.65fr);gap:44px;align-items:center;padding:58px 0 46px}.kicker{display:block;color:var(--primary);font-size:10px;font-weight:900;letter-spacing:.16em;text-transform:uppercase}.hero h1{font-size:clamp(48px,6vw,74px);line-height:.96;letter-spacing:-.055em;margin:12px 0 18px}.hero h1 span{color:var(--primary)}.hero-main>p{max-width:620px;color:var(--muted);font-size:17px;margin:0 0 22px}.main-search{max-width:700px;height:58px;display:flex;align-items:center;gap:10px;background:var(--card);border:1px solid var(--line);border-radius:16px;padding:0 13px;box-shadow:var(--shadow)}.main-search:focus-within{border-color:var(--primary);box-shadow:0 0 0 4px var(--soft)}.search-icon{font-size:24px;color:var(--muted)}.main-search input{flex:1;min-width:0;border:0;background:transparent;color:var(--text);outline:0;font-size:16px}.main-search kbd{border:1px solid var(--line);border-radius:6px;background:var(--card2);padding:2px 7px;color:var(--muted);font-size:11px}.quick-links{display:flex;gap:7px;flex-wrap:wrap;margin-top:12px}.quick-links button{border:0;background:var(--soft);color:var(--primary);font-size:12px;font-weight:800;border-radius:999px;padding:7px 11px}
.mini-calculator{background:var(--card);border:1px solid var(--line);border-radius:24px;padding:17px;box-shadow:var(--shadow)}.mini-top{display:flex;align-items:center;justify-content:space-between}.mini-top small{display:block;color:var(--muted);font-size:9px;letter-spacing:.14em}.mini-top strong{display:block;font-size:13px}.mini-top button{height:38px;border:1px solid var(--line);background:var(--card2);color:var(--text);border-radius:10px;padding:0 12px}.mini-screen{min-height:100px;margin:13px 0 10px;padding:15px;background:var(--bg);border-radius:16px;display:flex;flex-direction:column;align-items:flex-end;justify-content:flex-end;overflow:hidden}.mini-screen span{color:var(--muted);word-break:break-all}.mini-screen strong{font-size:36px;letter-spacing:-.04em;line-height:1.05;word-break:break-all}.mini-pad{display:grid;grid-template-columns:repeat(4,1fr);gap:8px}.mini-pad button{height:48px;border:1px solid var(--line);background:var(--card2);color:var(--text);border-radius:12px;font-weight:850}.mini-pad .op{color:var(--primary);background:var(--soft)}.mini-pad .equal{background:var(--primary);color:#fff;border-color:var(--primary)}.mini-note{margin:9px 0 0;color:var(--muted);font-size:10px}
.section{margin:48px 0}.section-heading,.tools-head{display:flex;justify-content:space-between;align-items:end;gap:16px;margin-bottom:18px}.section-heading h2,.tools-head h2{font-size:30px;line-height:1.1;letter-spacing:-.035em;margin:5px 0 0}.section-note,.tools-head p{color:var(--muted);font-size:12px;margin:5px 0 0}.category-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:11px}.category-card{position:relative;min-height:160px;text-align:left;border:1px solid var(--line);background:var(--card);color:var(--text);border-radius:19px;padding:18px;transition:.17s ease}.category-card:hover,.tool-card:hover,.popular-card:hover{border-color:var(--primary);transform:translateY(-2px);box-shadow:var(--shadow)}.category-icon{font-size:27px;margin-bottom:17px}.category-card h3{font-size:16px;margin:0 0 5px}.category-card p{font-size:11.5px;color:var(--muted);margin:0;max-width:92%}.category-count{position:absolute;right:14px;top:14px;background:var(--card2);color:var(--muted);border-radius:999px;padding:4px 8px;font-size:9px;font-weight:800}.category-examples{display:block;color:var(--primary);font-size:10.5px;font-weight:750;margin-top:9px}
.popular-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:11px}.popular-card{min-height:105px;display:flex;gap:12px;align-items:flex-start;text-align:left;border:1px solid var(--line);background:var(--card);color:var(--text);border-radius:17px;padding:16px;transition:.17s ease}.popular-icon{width:40px;height:40px;display:grid;place-items:center;border-radius:11px;background:var(--soft);color:var(--primary);font-weight:900;flex:0 0 auto}.popular-card strong{display:block;font-size:14px;margin-top:1px}.popular-card span:last-child>small{display:block;color:var(--muted);font-size:10.5px;line-height:1.35;margin-top:3px}
.tools-head{align-items:center}.soft-btn{height:40px;border:0;border-radius:11px;background:var(--card2);color:var(--text);font-weight:800;padding:0 13px}.filter-pills{display:flex;gap:7px;flex-wrap:wrap;margin-bottom:15px}.filter-pill{border:1px solid var(--line);background:var(--card);color:var(--muted);border-radius:999px;padding:8px 11px;font-size:11px;font-weight:750}.filter-pill.active{background:var(--primary);border-color:var(--primary);color:#fff}.tool-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:11px}.tool-card{position:relative;min-height:142px;text-align:left;border:1px solid var(--line);background:var(--card);color:var(--text);border-radius:17px;padding:17px;transition:.17s ease}.tool-icon{width:40px;height:40px;display:grid;place-items:center;background:var(--card2);border-radius:11px;font-weight:900;margin-bottom:17px}.tool-card h3{font-size:14px;line-height:1.25;margin:0 0 5px}.tool-card p{font-size:11px;line-height:1.4;color:var(--muted);margin:0}.tool-tag{position:absolute;top:12px;right:12px;border-radius:999px;background:var(--soft);color:var(--primary);font-size:8.5px;font-weight:900;padding:4px 7px;text-transform:uppercase}.empty{border:1px dashed var(--line);background:var(--card);border-radius:17px;padding:44px;text-align:center}.empty strong{display:block}.empty span{display:block;color:var(--muted);font-size:12px;margin-top:4px}
.saved-grid{display:grid;grid-template-columns:1fr 1fr;gap:12px}.saved-card{background:var(--card);border:1px solid var(--line);border-radius:17px;padding:18px}.saved-card h3{font-size:19px;margin:4px 0 12px}.saved-list{display:flex;gap:7px;flex-wrap:wrap}.saved-btn{border:1px solid var(--line);background:var(--bg);color:var(--text);border-radius:9px;padding:8px 10px;font-size:11px}.muted{color:var(--muted);font-size:11px}
.calc-page{padding-top:24px}.back-btn{height:42px;border:1px solid var(--line);background:var(--card);color:var(--text);border-radius:11px;padding:0 14px;font-weight:750;margin-bottom:14px}.calc-layout{display:grid;grid-template-columns:minmax(0,1fr) 275px;gap:16px;align-items:start}.calc-card{background:var(--card);border:1px solid var(--line);border-radius:22px;padding:27px;min-width:0}.calc-titlebar{display:flex;gap:18px;justify-content:space-between;border-bottom:1px solid var(--line);padding-bottom:20px;margin-bottom:22px}.calc-titlebar h1{font-size:34px;letter-spacing:-.04em;margin:5px 0 6px}.calc-titlebar p{color:var(--muted);margin:0;font-size:13px}.fav-btn{width:42px;height:42px;border:1px solid var(--line);background:var(--card2);color:var(--text);border-radius:11px;font-size:21px;flex:0 0 auto}.about-box{margin-top:28px;padding-top:22px;border-top:1px solid var(--line)}.about-box h2{font-size:19px;margin:0 0 7px}.about-box p{margin:0;color:var(--muted);line-height:1.65}.calc-sidebar{display:grid;gap:11px}.side-box{background:var(--card);border:1px solid var(--line);border-radius:17px;padding:16px}.related{display:grid;gap:7px;margin-top:11px}.related button{border:1px solid var(--line);background:var(--bg);color:var(--text);border-radius:9px;padding:10px;text-align:left;font-size:11px}.compact-info strong{display:block;font-size:13px}.compact-info p{margin:5px 0 0;color:var(--muted);font-size:11px}
.form{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px}.field{display:grid;gap:6px;min-width:0}.field.full,.actions,.result,.note,.tapstage,.scipad{grid-column:1/-1}.field label{font-size:12px;font-weight:800}.field small{color:var(--muted);font-size:11px}input[type=number],input[type=text],input[type=date],input[type=time],select,textarea{width:100%;height:48px;border:1px solid var(--line);border-radius:12px;background:var(--bg);color:var(--text);padding:0 12px;outline:none;font-size:16px}textarea{height:112px;padding:12px;resize:vertical}input:focus,select:focus,textarea:focus{border-color:var(--primary);box-shadow:0 0 0 3px var(--soft)}.actions{display:flex;gap:8px;flex-wrap:wrap;margin-top:2px}.primary,.secondary{height:44px;border:0;border-radius:11px;padding:0 17px;font-weight:900}.primary{background:var(--primary);color:#fff}.secondary{background:var(--card2);color:var(--text)}.note{border-left:3px solid var(--primary);background:var(--card2);padding:10px 12px;border-radius:0 9px 9px 0;color:var(--muted);font-size:11px}.result{background:var(--soft);border:1px solid var(--line);border-radius:15px;padding:17px}.result small{display:block;color:var(--muted);font-size:10px;font-weight:900;text-transform:uppercase;letter-spacing:.08em}.big{font-size:34px;font-weight:950;letter-spacing:-.04em;word-break:break-word}.rgrid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:8px;margin-top:11px}.rgrid>div{background:var(--card);border-radius:9px;padding:10px}.rgrid span{display:block;color:var(--muted);font-size:9.5px}.rgrid b{font-size:13px;word-break:break-word}.tapdisplay{min-height:120px;border:1px solid var(--line);background:var(--bg);border-radius:17px;display:flex;align-items:center;justify-content:flex-end;padding:15px;font-size:clamp(38px,8vw,70px);font-weight:900;overflow:auto}.tappad{display:grid;grid-template-columns:repeat(3,1fr);gap:8px}.tappad button{height:60px;border:1px solid var(--line);background:var(--card2);color:var(--text);border-radius:13px;font-size:21px;font-weight:900}.counter{text-align:center;font-size:76px;font-weight:900}.counterbtn{height:82px!important;font-size:25px!important}.scipad{display:grid;grid-template-columns:repeat(6,1fr);gap:7px}.scipad button{height:43px;border:1px solid var(--line);background:var(--card2);color:var(--text);border-radius:9px;font-weight:800}.canvas{width:100%;height:370px;border:1px solid var(--line);border-radius:13px;background:var(--bg)}.matrix{display:grid;grid-template-columns:repeat(3,1fr);gap:6px}.matrix input{text-align:center}.checks{display:flex;gap:8px;flex-wrap:wrap}.badge{display:inline-flex;align-items:center;gap:5px;border-radius:999px;padding:5px 9px;background:var(--card2);font-size:11px;color:var(--muted)}
.footer{max-width:1200px;margin:20px auto 0;padding:27px 22px 40px;border-top:1px solid var(--line);display:flex;justify-content:space-between;gap:18px;color:var(--muted);font-size:10.5px}.footer strong{color:var(--text)}.toast{position:fixed;left:50%;bottom:20px;transform:translate(-50%,25px);opacity:0;pointer-events:none;background:var(--text);color:var(--bg);border-radius:10px;padding:10px 14px;font-size:11px;transition:.2s;z-index:50}.toast.show{opacity:1;transform:translate(-50%,0)}
@media(max-width:1000px){.category-grid,.popular-grid,.tool-grid{grid-template-columns:repeat(3,1fr)}.calc-layout{grid-template-columns:1fr}.calc-sidebar{grid-template-columns:1fr 1fr}.compact-info{grid-column:1/-1}}
@media(max-width:760px){.site-header,main{padding-left:14px;padding-right:14px}.header-link{display:none}.hero{grid-template-columns:1fr;padding:33px 0}.hero h1{font-size:46px}.category-grid,.popular-grid,.tool-grid{grid-template-columns:repeat(2,1fr)}.saved-grid{grid-template-columns:1fr}.section-heading{align-items:flex-start}.section-note{display:none}.calc-sidebar{grid-template-columns:1fr}.compact-info{grid-column:auto}.rgrid{grid-template-columns:1fr 1fr}.scipad{grid-template-columns:repeat(4,1fr)}}
@media(max-width:500px){.site-header{height:64px}.brand-text small{display:none}.hero h1{font-size:39px}.hero-main>p{font-size:15px}.mini-calculator{border-radius:18px;padding:12px}.category-grid{grid-template-columns:1fr 1fr}.category-card{min-height:145px;padding:14px}.category-card h3{font-size:14px}.category-card p{font-size:10.5px}.popular-grid{grid-template-columns:1fr}.tool-grid{grid-template-columns:1fr}.form{grid-template-columns:1fr}.field.full,.actions,.result,.note,.tapstage,.scipad{grid-column:1}.calc-card{padding:17px}.calc-titlebar h1{font-size:28px}.rgrid{grid-template-columns:1fr}.footer{flex-direction:column}.canvas{height:290px}}

/* V4 brand + SEO content */
.brand{gap:10px}.brand-logo{filter:drop-shadow(0 5px 12px rgba(99,91,255,.16))}
.seo-page-content{margin:24px 0 0;background:var(--card);border:1px solid var(--line);border-radius:22px;padding:26px}
.seo-page-content h2{font-size:24px;letter-spacing:-.025em;margin:0 0 10px}
.seo-page-content h3{font-size:17px;margin:24px 0 7px}
.seo-page-content p{color:var(--muted);line-height:1.75;margin:0 0 12px}
.seo-page-content .seo-formula{background:var(--card2);border-left:4px solid var(--primary);border-radius:0 12px 12px 0;padding:13px 15px;color:var(--text)}
.seo-page-content .seo-links{display:flex;flex-wrap:wrap;gap:8px;margin-top:10px}
.seo-page-content .seo-links a{border:1px solid var(--line);background:var(--bg);border-radius:999px;padding:8px 11px;font-size:11px;color:var(--text)}
.seo-page-content .seo-links a:hover{border-color:var(--primary);color:var(--primary)}
.seo-page-content .faq-item{padding:14px 0;border-top:1px solid var(--line)}
.seo-page-content .faq-item:first-of-type{border-top:0}
.seo-page-content .faq-item strong{display:block;margin-bottom:4px}
.breadcrumb-static{font-size:11px;color:var(--muted);margin:0 0 12px}
.breadcrumb-static a{color:var(--primary)}
.home-seo{margin:46px 0;background:var(--card);border:1px solid var(--line);border-radius:20px;padding:24px}
.home-seo h2{font-size:24px;margin:0 0 8px}.home-seo p{color:var(--muted);line-height:1.75;margin:0}
@media(max-width:500px){.brand-logo{width:42px;height:42px}.seo-page-content{padding:18px;border-radius:17px}.seo-page-content h2{font-size:21px}}