:root{
  --bg:#ffffff;--fg:#0f172a;--muted:#64748b;--border:#e2e8f0;
  --primary:#4f46e5;--primary-hover:#4338ca;--accent:#10b981;
  --card:#ffffff;--card-shadow:0 6px 24px -8px rgba(15,23,42,.12);
  --radius:14px;--radius-sm:10px;
  --font-display:'Outfit',system-ui,sans-serif;
  --font-body:'Figtree',system-ui,sans-serif;
}
@media (prefers-color-scheme: dark){
  :root{--bg:#0b1020;--fg:#f1f5f9;--muted:#94a3b8;--border:#1e293b;--card:#111835;--card-shadow:0 6px 24px -8px rgba(0,0,0,.5);}
}
*{box-sizing:border-box}
html,body{margin:0;padding:0;background:var(--bg);color:var(--fg);font-family:var(--font-body);line-height:1.6;-webkit-font-smoothing:antialiased}
h1,h2,h3,h4{font-family:var(--font-display);font-weight:700;line-height:1.2;letter-spacing:-.02em;margin:0 0 .5em}
h1{font-size:clamp(2rem,4.5vw,3rem)}h2{font-size:clamp(1.5rem,3vw,2rem)}h3{font-size:1.25rem}
p{margin:0 0 1em}
a{color:var(--primary);text-decoration:none}a:hover{text-decoration:underline}
img{max-width:100%;height:auto}
.container{max-width:1120px;margin:0 auto;padding:0 1.25rem}
/* Header */
.site-header{position:sticky;top:0;z-index:50;background:color-mix(in oklab,var(--bg) 85%,transparent);backdrop-filter:blur(12px);border-bottom:1px solid var(--border)}
.site-header .inner{display:flex;align-items:center;justify-content:space-between;padding:.85rem 0;gap:1rem}
.logo{font-family:var(--font-display);font-weight:800;font-size:1.25rem;color:var(--fg);display:flex;align-items:center;gap:.5rem}
.logo-mark{display:inline-grid;place-items:center;width:32px;height:32px;border-radius:8px;background:linear-gradient(135deg,var(--primary),var(--accent));color:#fff;font-size:.9rem}
.nav{display:flex;gap:.25rem;flex-wrap:wrap}
.nav a{padding:.45rem .75rem;border-radius:8px;color:var(--fg);font-size:.92rem;font-weight:500}
.nav a:hover{background:color-mix(in oklab,var(--primary) 10%,transparent);text-decoration:none}
.nav a.active{background:color-mix(in oklab,var(--primary) 14%,transparent);color:var(--primary)}
.menu-toggle{display:none;background:none;border:1px solid var(--border);border-radius:8px;padding:.5rem .75rem;color:var(--fg);cursor:pointer}
@media (max-width:880px){.menu-toggle{display:inline-block}.nav{display:none;position:absolute;top:100%;left:0;right:0;flex-direction:column;background:var(--bg);border-bottom:1px solid var(--border);padding:.5rem 1rem 1rem}.nav.open{display:flex}.site-header{position:relative}}
/* Hero */
.hero{padding:3.5rem 0 2rem;text-align:center;background:radial-gradient(ellipse at top,color-mix(in oklab,var(--primary) 12%,transparent),transparent 60%)}
.hero p.lead{color:var(--muted);font-size:1.15rem;max-width:680px;margin:0 auto 1.5rem}
.btn{display:inline-block;padding:.7rem 1.2rem;border-radius:10px;font-weight:600;border:none;cursor:pointer;font-family:inherit;font-size:.95rem;transition:transform .15s,background .15s}
.btn-primary{background:var(--primary);color:#fff}.btn-primary:hover{background:var(--primary-hover);text-decoration:none;transform:translateY(-1px)}
.btn-ghost{background:transparent;color:var(--fg);border:1px solid var(--border)}
/* Cards grid */
.section{padding:3rem 0}
.section h2{text-align:center;margin-bottom:.4rem}
.section .subtitle{text-align:center;color:var(--muted);margin-bottom:2rem}
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:1rem}
.card{background:var(--card);border:1px solid var(--border);border-radius:var(--radius);padding:1.25rem;box-shadow:var(--card-shadow);transition:transform .2s,box-shadow .2s;display:block;color:var(--fg)}
.card:hover{transform:translateY(-3px);text-decoration:none;box-shadow:0 12px 30px -10px rgba(79,70,229,.25)}
.card .emoji{font-size:1.8rem;display:block;margin-bottom:.5rem}
.card h3{margin:0 0 .25rem;font-size:1.1rem}
.card p{margin:0;color:var(--muted);font-size:.92rem}
.tag{display:inline-block;font-size:.72rem;background:color-mix(in oklab,var(--primary) 12%,transparent);color:var(--primary);padding:.15rem .5rem;border-radius:99px;margin-top:.6rem;font-weight:600}
/* Tool layout */
.tool-wrap{display:grid;grid-template-columns:minmax(0,1fr);gap:1.5rem;padding:2rem 0}
@media (min-width:980px){.tool-wrap{grid-template-columns:minmax(0,2fr) minmax(0,1fr)}}
.tool-card{background:var(--card);border:1px solid var(--border);border-radius:var(--radius);padding:1.5rem;box-shadow:var(--card-shadow)}
.tool-card h1{margin-bottom:.25rem}
.tool-card .lead{color:var(--muted);margin-bottom:1.25rem}
label{display:block;font-weight:500;font-size:.9rem;margin-bottom:.35rem}
input,select{width:100%;padding:.65rem .8rem;border:1px solid var(--border);border-radius:10px;background:var(--bg);color:var(--fg);font:inherit;font-size:.95rem}
input:focus,select:focus{outline:2px solid color-mix(in oklab,var(--primary) 40%,transparent);outline-offset:1px;border-color:var(--primary)}
.field{margin-bottom:1rem}
.row{display:grid;grid-template-columns:repeat(auto-fit,minmax(140px,1fr));gap:.85rem}
.result{margin-top:1.5rem;padding:1.25rem;border-radius:12px;background:linear-gradient(135deg,color-mix(in oklab,var(--primary) 10%,transparent),color-mix(in oklab,var(--accent) 8%,transparent));border:1px solid color-mix(in oklab,var(--primary) 25%,transparent)}
.result .label{font-size:.85rem;color:var(--muted);text-transform:uppercase;letter-spacing:.05em;font-weight:600}
.result .value{font-family:var(--font-display);font-size:2.5rem;font-weight:700;color:var(--primary);line-height:1.1;margin:.2rem 0}
.result .meta{color:var(--muted);font-size:.9rem}
.sidebar .tool-card{padding:1.25rem}
.sidebar h3{font-size:1rem;margin-bottom:.75rem}
.sidebar ul{list-style:none;padding:0;margin:0}
.sidebar li{margin-bottom:.45rem}
.sidebar a{color:var(--fg);font-size:.92rem}
.breadcrumb{font-size:.85rem;color:var(--muted);margin:1.25rem 0 .5rem}
.breadcrumb a{color:var(--muted)}.breadcrumb a:hover{color:var(--primary)}
.faq{margin-top:2rem}
.faq details{background:var(--card);border:1px solid var(--border);border-radius:10px;padding:.85rem 1rem;margin-bottom:.6rem}
.faq summary{font-weight:600;cursor:pointer;list-style:none}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:'+';float:right;font-weight:400;color:var(--muted)}
.faq details[open] summary::after{content:'−'}
.faq details p{margin:.6rem 0 0;color:var(--muted)}
/* Footer */
.site-footer{margin-top:4rem;padding:2.5rem 0 1.5rem;border-top:1px solid var(--border);background:color-mix(in oklab,var(--bg) 96%,#000 4%)}
.footer-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(180px,1fr));gap:2rem;margin-bottom:1.5rem}
.footer-grid h4{font-size:.9rem;text-transform:uppercase;letter-spacing:.05em;margin-bottom:.75rem;color:var(--muted)}
.footer-grid ul{list-style:none;padding:0;margin:0}
.footer-grid li{margin-bottom:.4rem}
.footer-grid a{color:var(--fg);font-size:.92rem}
.copyright{text-align:center;color:var(--muted);font-size:.85rem;padding-top:1.5rem;border-top:1px solid var(--border)}
/* Back to top */
#backToTop{position:fixed;bottom:1.25rem;right:1.25rem;width:42px;height:42px;border-radius:50%;background:var(--primary);color:#fff;border:none;cursor:pointer;display:none;align-items:center;justify-content:center;font-size:1.1rem;box-shadow:0 8px 20px -6px rgba(79,70,229,.5);z-index:40}
#backToTop.show{display:flex}
/* Article */
.article{max-width:780px;margin:0 auto;padding:2rem 0}
.article h2{margin-top:2rem}.article ul,.article ol{padding-left:1.4rem}
.table-wrap{overflow-x:auto;margin:1rem 0}
table{width:100%;border-collapse:collapse;font-size:.95rem}
th,td{padding:.65rem .85rem;border:1px solid var(--border);text-align:left}
th{background:color-mix(in oklab,var(--primary) 8%,transparent);font-weight:600}