:root{--bg: #ffffff;--surface: #f6f8fb;--border: #dde3ec;--text: #0f172a;--muted: #475569;--primary: #326ce5;--primary-hover: #1e4fc4;--accent: #0d9488;--danger: #dc2626;--radius: 10px;--shadow: 0 1px 2px rgba(15, 23, 42, .05), 0 1px 3px rgba(15, 23, 42, .05);--max-width: 980px;--font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, "Helvetica Neue", sans-serif;--font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;--focus-ring: rgba(50, 108, 229, .35)}@media(prefers-color-scheme:dark){:root{--bg: #0b1220;--surface: #131b2c;--border: #283447;--text: #e8edf5;--muted: #94a3b8;--primary: #5b8dff;--primary-hover: #7ba2ff;--focus-ring: rgba(91, 141, 255, .45)}}*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;font-family:var(--font-sans);font-size:16px;line-height:1.6;color:var(--text);background:var(--bg);-webkit-font-smoothing:antialiased}a{color:var(--primary);text-decoration:none}a:hover{text-decoration:underline}img,svg{max-width:100%;display:block}:focus-visible{outline:2px solid var(--primary);outline-offset:2px;border-radius:4px}.container{max-width:var(--max-width);margin:0 auto;padding:0 20px}.site-header{border-bottom:1px solid var(--border);background:var(--bg);position:sticky;top:0;z-index:50}.site-header .inner{display:flex;align-items:center;justify-content:space-between;padding:14px 20px;max-width:var(--max-width);margin:0 auto}.brand{font-weight:700;font-size:1.15rem;color:var(--text);letter-spacing:-.01em}.brand:hover{text-decoration:none}.brand .dot{color:var(--primary)}.nav{display:flex;gap:22px;align-items:center}.nav a{color:var(--muted);font-size:.95rem}.nav a:hover{color:var(--text);text-decoration:none}.hero{padding:60px 0 40px;text-align:center}.hero h1{font-size:clamp(1.9rem,4vw,2.6rem);margin:0 0 14px;letter-spacing:-.02em}.hero p{font-size:1.1rem;color:var(--muted);max-width:640px;margin:0 auto}.category{margin:36px 0 12px;font-size:.85rem;text-transform:uppercase;letter-spacing:.08em;color:var(--muted);font-weight:600}.tool-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:16px}.tool-card{display:block;border:1px solid var(--border);border-radius:var(--radius);padding:20px;background:var(--surface);transition:transform .15s ease,border-color .15s ease}.tool-card:hover{text-decoration:none;border-color:var(--primary);transform:translateY(-2px)}.tool-card h3{margin:0 0 6px;font-size:1.05rem;color:var(--text)}.tool-card p{margin:0;color:var(--muted);font-size:.92rem}.tool-card .icon{font-size:1.4rem;margin-bottom:8px;display:inline-block}.tool-page main{padding:28px 0 60px}.tool-page h1{font-size:clamp(1.6rem,3.5vw,2.1rem);margin:0 0 8px;letter-spacing:-.01em}.tool-page .lede{color:var(--muted);margin:0 0 24px;font-size:1.05rem}.breadcrumbs{font-size:.9rem;color:var(--muted);margin:0 0 18px}.breadcrumbs a{color:var(--muted)}.breadcrumbs a:hover{color:var(--text)}.tool-card-box{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:24px;box-shadow:var(--shadow);margin-bottom:28px}label{display:block;font-weight:600;font-size:.93rem;margin-bottom:6px}.field{margin-bottom:14px}.field-row{display:grid;gap:12px;grid-template-columns:1fr 1fr}@media(max-width:560px){.field-row{grid-template-columns:1fr}}input[type=number],input[type=text],input[type=date],select,textarea{width:100%;padding:10px 12px;font-size:1rem;border:1px solid var(--border);border-radius:8px;background:var(--bg);color:var(--text);font-family:inherit}textarea{font-family:var(--font-mono);font-size:.92rem;min-height:180px;resize:vertical}input:focus,select:focus,textarea:focus{outline:none;border-color:var(--primary);box-shadow:0 0 0 3px var(--focus-ring)}.btn{display:inline-block;padding:10px 18px;font-size:1rem;font-weight:600;border:0;border-radius:8px;background:var(--primary);color:#fff;cursor:pointer;font-family:inherit;transition:background .12s ease}.btn:hover{background:var(--primary-hover)}.btn.secondary{background:transparent;color:var(--text);border:1px solid var(--border)}.btn.secondary:hover{background:var(--surface)}.btn-row{display:flex;gap:8px;flex-wrap:wrap}.result{margin-top:18px;padding:18px;background:var(--bg);border:1px solid var(--border);border-radius:8px}.result .big{font-size:2rem;font-weight:700;color:var(--text);letter-spacing:-.01em}.result .label{color:var(--muted);font-size:.9rem;margin-bottom:4px}.result-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(140px,1fr));gap:16px}.result-item{padding:12px;background:var(--surface);border-radius:8px}.content-section{margin-top:40px}.content-section h2{font-size:1.45rem;margin:28px 0 10px;letter-spacing:-.01em}.content-section h3{font-size:1.1rem;margin:20px 0 6px}.content-section p,.content-section li{color:var(--text)}details{border:1px solid var(--border);border-radius:8px;padding:12px 16px;margin-bottom:8px;background:var(--surface)}details summary{cursor:pointer;font-weight:600;list-style:none}details summary::-webkit-details-marker{display:none}details summary:after{content:" +";color:var(--muted)}details[open] summary:after{content:" −"}table{width:100%;border-collapse:collapse;font-size:.93rem;margin:12px 0}table th,table td{border:1px solid var(--border);padding:8px 10px;text-align:left}table th{background:var(--surface)}.site-footer{border-top:1px solid var(--border);margin-top:60px;padding:28px 0;color:var(--muted);font-size:.92rem}.site-footer .inner{display:flex;flex-wrap:wrap;gap:12px;justify-content:space-between;align-items:center}.site-footer a,.muted{color:var(--muted)}.mono{font-family:var(--font-mono)}.error{color:var(--danger);font-size:.9rem;margin-top:6px}.success{color:var(--accent)}