:root{--primary:#1a73e8;--primary-dark:#0d47a1;--bg:#f5f7fa;--card:#fff;--text:#1d1d1d;--muted:#666;--border:#e8edf5;--radius:10px;--shadow:0 1px 6px rgba(0,0,0,.05);--shadow-hover:0 3px 16px rgba(0,0,0,.08);--transition:.2s}
*{margin:0;padding:0;box-sizing:border-box}
body{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;background:var(--bg);color:var(--text);line-height:1.6;min-height:100vh;display:flex;flex-direction:column}

.site-header{background:linear-gradient(135deg,var(--primary),var(--primary-dark));color:#fff;padding:24px 20px;text-align:center}
.site-header h1{font-size:1.6em;font-weight:700}
.site-header p{font-size:.9em;opacity:.85;max-width:500px;margin:4px auto 0}
.site-header .breadcrumb{margin-top:10px;font-size:.82em;opacity:.7;display:flex;gap:6px;justify-content:center;flex-wrap:wrap}
.site-header .breadcrumb a{color:#fff;text-decoration:none;opacity:.8}
.site-header .breadcrumb a:hover{opacity:1;text-decoration:underline}
.site-header .breadcrumb .sep{opacity:.4}

.container{max-width:1000px;margin:0 auto;padding:20px 16px 40px;flex:1}
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:12px}

.card{background:var(--card);border-radius:var(--radius);padding:18px 20px;box-shadow:var(--shadow);text-decoration:none;color:var(--text);display:flex;align-items:flex-start;gap:14px;transition:box-shadow var(--transition),transform var(--transition);border:1px solid var(--border)}
.card:hover{box-shadow:var(--shadow-hover);transform:translateY(-1px)}
.card .icon{font-size:1.5em;flex-shrink:0;width:36px;text-align:center;margin-top:2px}
.card .body{flex:1;min-width:0}
.card .body h3{font-size:.95em;font-weight:600;margin-bottom:3px}
.card .body p{font-size:.82em;color:var(--muted);line-height:1.5}
.card .body .meta{display:flex;gap:8px;margin-top:6px;flex-wrap:wrap}
.card .body .tag{font-size:.72em;padding:2px 8px;border-radius:10px;background:#e8f0fe;color:var(--primary)}
.card .body .tag.green{background:#e8f5e9;color:#2e7d32}
.card .body .tag.gray{background:#f0f0f0;color:#888}

.section{margin-bottom:28px}
.section h2{font-size:1.1em;color:var(--muted);margin-bottom:12px;padding-left:10px;border-left:3px solid var(--primary)}

.tool-box{background:var(--card);border-radius:12px;padding:28px 24px;box-shadow:0 2px 12px rgba(0,0,0,.06);margin-bottom:20px}
.tool-box h2{font-size:1.15em;margin-bottom:16px;display:flex;align-items:center;gap:8px}
.tool-grid{display:grid;grid-template-columns:1fr 1fr;gap:16px}
@media(max-width:640px){.tool-grid{grid-template-columns:1fr}}
.field label{display:block;font-size:.88em;font-weight:600;margin-bottom:4px;color:#555}
.field .input-group{display:flex;align-items:center;border:2px solid #e0e0e0;border-radius:8px;overflow:hidden;transition:border-color .2s}
.field .input-group:focus-within{border-color:var(--primary)}
.field input,.field select{flex:1;border:none;outline:none;padding:10px 12px;font-size:1em;background:transparent}
.field .unit{padding:10px 12px;background:#f0f4f8;color:#555;font-size:.88em;font-weight:500;border-left:2px solid #e0e0e0;min-width:40px;text-align:center}
.btn{display:block;width:100%;padding:14px;background:var(--primary);color:#fff;border:none;border-radius:8px;font-size:1.05em;font-weight:600;cursor:pointer;transition:background .2s}
.btn:hover{background:#1557b0}
.result-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:12px;margin-top:8px}
.result-item{background:#f8faff;border-radius:10px;padding:16px;text-align:center;border:1px solid var(--border)}
.result-item .value{font-size:1.5em;font-weight:700;color:var(--primary)}
.result-item .label{font-size:.82em;color:var(--muted);margin-top:2px}
.compliance{display:flex;flex-wrap:wrap;gap:8px;margin-top:12px}
.compliance .tag{padding:4px 10px;border-radius:20px;font-size:.78em;font-weight:500;background:#e8f5e9;color:#2e7d32}
.compliance .tag.fail{background:#fbe9e7;color:#c62828}
.note{font-size:.85em;color:var(--muted);margin-top:12px;padding:12px;background:#f8f9fa;border-radius:8px;border-left:3px solid var(--primary)}
.diagram{max-width:100%;height:auto;margin:20px auto;display:block;background:#fafbfc;border-radius:8px;padding:16px}
.diagram svg{width:100%;height:auto}
.sourcenote{text-align:right;font-size:.78em;color:var(--muted);margin-top:4px}
.ref-table{width:100%;border-collapse:collapse;font-size:.85em}
.ref-table th{padding:8px 6px;border-bottom:2px solid #ddd;text-align:left}
.ref-table td{padding:8px 6px;border-bottom:1px solid #eee}
.ref-table th.ctr,.ref-table td.ctr{text-align:center}
.site-footer{text-align:center;padding:20px 16px 28px;color:var(--muted);font-size:.8em;border-top:1px solid var(--border);margin-top:auto}
.site-footer a{color:var(--primary);text-decoration:none}
.site-footer .links{margin-top:6px;display:flex;gap:12px;justify-content:center;flex-wrap:wrap}
.site-footer .links a{font-size:.88em}

@media(prefers-color-scheme:dark){:root{--bg:#111;--card:#1a1a2e;--text:#eee;--muted:#999;--border:#2a2a3e}.card,.tool-box,.result-item,.note{border-color:var(--border);box-shadow:0 2px 12px rgba(0,0,0,.2)}.card .body .tag{background:#0d2137;color:#64b5f6}.card .body .tag.green{background:#1b3a2b;color:#81c784}.card .body .tag.gray{background:#222;color:#777}.field .input-group{border-color:#333}.field .unit{background:#222;color:#aaa;border-left-color:#333}.result-item{background:#16213e}.note{background:#1a1a2e}.compliance .tag{background:#1b3a2b;color:#81c784}.compliance .tag.fail{background:#3e1a1a;color:#ef9a9a}.ref-table td,.ref-table th{border-color:#2a2a3e}}