:root{--tool-blue:#0d3b66;--tool-dark:#082a49;--tool-orange:#f4a261;--tool-bg:#f6f8fb;--tool-text:#172033;--tool-muted:#64748b;--tool-line:#d9e2ea;--tool-ok:#176534;--tool-bad:#9b1c1c}
.tools-hero{padding:72px 0 58px;background:linear-gradient(135deg,#082a49,#0d3b66);color:#fff}.tools-hero h1{margin:8px 0 12px;color:#fff}.tools-hero p{max-width:780px;color:#dce9f5}.tools-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:22px}.tool-category-card{display:flex;flex-direction:column;min-height:250px;padding:26px;border:1px solid var(--tool-line);border-radius:18px;background:#fff;box-shadow:0 8px 24px rgba(8,42,73,.07);transition:.2s}.tool-category-card:hover{transform:translateY(-3px);box-shadow:0 16px 38px rgba(8,42,73,.13)}.tool-icon{display:grid;width:52px;height:52px;place-items:center;border-radius:14px;background:#fff3e7;color:#a75418;font-size:1.5rem;font-weight:900}.tool-category-card h2{margin:18px 0 10px;color:var(--tool-blue);font-size:1.3rem}.tool-category-card p{color:var(--tool-muted);line-height:1.6}.tool-category-card .btn{margin-top:auto;align-self:flex-start}.tools-note{margin-top:30px;padding:18px;border-left:4px solid var(--tool-orange);border-radius:10px;background:#fff8ed;color:#684321}.calculator-shell{display:grid;grid-template-columns:280px minmax(0,1fr);gap:26px;align-items:start}.calc-sidebar{position:sticky;top:90px;padding:18px;border:1px solid var(--tool-line);border-radius:16px;background:#fff}.calc-sidebar h2{margin-top:0;color:var(--tool-blue);font-size:1.1rem}.calc-nav{display:grid;gap:6px}.calc-nav button{width:100%;padding:10px 12px;border:0;border-radius:9px;background:transparent;color:var(--tool-text);font:inherit;text-align:left;cursor:pointer}.calc-nav button:hover,.calc-nav button.active{background:#eaf2f8;color:var(--tool-blue);font-weight:800}.calc-main{display:grid;gap:20px}.calc-panel{display:none;padding:26px;border:1px solid var(--tool-line);border-radius:18px;background:#fff;box-shadow:0 8px 24px rgba(8,42,73,.06)}.calc-panel.active{display:block}.calc-panel h2{margin-top:0;color:var(--tool-blue)}.calc-panel .formula{padding:12px 14px;border-radius:9px;background:#edf4f8;color:#29465f;font-family:ui-monospace,SFMono-Regular,Consolas,monospace}.calc-fields{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px;margin:20px 0}.calc-field{display:grid;gap:7px}.calc-field label{font-size:.88rem;font-weight:800;color:var(--tool-text)}.calc-field input,.calc-field select{width:100%;height:48px;padding:10px 12px;border:1px solid #cbd5e1;border-radius:9px;background:#fff;font:inherit}.calc-field input:focus,.calc-field select:focus{outline:3px solid rgba(244,162,97,.28);border-color:var(--tool-orange)}.calc-actions{display:flex;gap:10px;flex-wrap:wrap}.calc-btn{border:0;border-radius:9px;padding:11px 18px;background:var(--tool-blue);color:#fff;font:inherit;font-weight:850;cursor:pointer}.calc-btn.secondary{background:#e8eef3;color:var(--tool-blue)}.calc-result{display:none;margin-top:18px;padding:18px;border-radius:12px;background:#eaf8ef;color:var(--tool-ok)}.calc-result.show{display:block}.calc-result strong{display:block;font-size:1.45rem}.calc-error{display:none;margin-top:14px;padding:12px;border-radius:9px;background:#fff0f0;color:var(--tool-bad)}.calc-error.show{display:block}.back-tools{display:inline-flex;margin-bottom:18px;color:var(--tool-blue);font-weight:800;text-decoration:none}.tool-disclaimer{margin-top:26px;padding:17px;border-radius:12px;background:#fff8ed;color:#684321;font-size:.9rem}.source-box{margin-top:14px;color:var(--tool-muted);font-size:.82rem}.source-box a{color:var(--tool-blue)}
@media(max-width:960px){.tools-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.calculator-shell{grid-template-columns:1fr}.calc-sidebar{position:static}.calc-nav{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media(max-width:650px){.tools-grid,.calc-fields,.calc-nav{grid-template-columns:1fr}.calc-panel{padding:20px}.tools-hero{padding:54px 0 45px}}

.chemical-page-tabs{display:flex;gap:10px;margin:0 0 18px}.chemical-page-tabs button{border:1px solid #cbd5e1;border-radius:10px;padding:12px 18px;background:#fff;color:var(--tool-blue);font:inherit;font-weight:850;cursor:pointer}.chemical-page-tabs button.active{background:var(--tool-blue);color:#fff;border-color:var(--tool-blue)}.sizing-workflow{padding:28px;border:1px solid #d9e2ea;border-radius:18px;background:#fff;box-shadow:0 8px 24px rgba(8,42,73,.06)}.workflow-header{max-width:900px}.workflow-header h2{color:var(--tool-blue)}.workflow-steps{display:grid;gap:14px;margin:24px 0 0;padding:0;list-style:none}.workflow-steps li{display:grid;grid-template-columns:56px 1fr;gap:16px;padding:20px;border:1px solid #dfe7ee;border-radius:14px;background:#fbfdff}.workflow-steps li>span{display:grid;width:48px;height:48px;place-items:center;border-radius:50%;background:#eaf2f8;color:var(--tool-blue);font-weight:900}.workflow-steps h3{margin:2px 0 8px;color:var(--tool-blue)}.workflow-steps p{margin:0 0 9px;line-height:1.65;color:#475569}.workflow-steps code{padding:2px 5px;border-radius:5px;background:#edf4f8;color:#29465f}.workflow-steps a{display:inline-block;margin:5px 8px 0 0;color:#a75418;font-weight:800;text-decoration:none}.workflow-steps a:hover{text-decoration:underline}.calc-field label span{color:var(--tool-muted);font-weight:600}@media(max-width:650px){.chemical-page-tabs{flex-direction:column}.workflow-steps li{grid-template-columns:1fr}.workflow-steps li>span{width:42px;height:42px}}

.calc-panel{scroll-margin-top:96px}.workflow-steps li{scroll-margin-top:96px}

.calc-history{margin-top:22px;padding-top:20px;border-top:1px solid #dbe4ec}.calc-history-head{display:flex;justify-content:space-between;align-items:center;gap:14px}.calc-history-head h3{margin:2px 0 0;color:var(--tool-blue)}.history-kicker{margin:0;color:var(--tool-muted);font-size:.76rem;font-weight:850;letter-spacing:.07em;text-transform:uppercase}.clear-history-btn{border:1px solid #e5b5b5;border-radius:8px;padding:9px 12px;background:#fff;color:var(--tool-bad);font:inherit;font-size:.84rem;font-weight:850;cursor:pointer}.clear-history-btn:disabled{cursor:not-allowed;opacity:.45}.calc-history-list{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px;margin-top:15px}.history-empty{grid-column:1/-1;margin:0;padding:16px;border:1px dashed #cbd5e1;border-radius:10px;background:#f8fafc;color:var(--tool-muted)}.history-card{padding:14px;border:1px solid #dbe4ec;border-radius:12px;background:#fbfdff}.history-card-top{display:flex;justify-content:space-between;gap:10px;color:var(--tool-muted);font-size:.78rem}.history-card-top span{font-weight:850;color:var(--tool-blue)}.history-result{margin:11px 0;padding:11px;border-radius:9px;background:#eaf8ef;color:var(--tool-ok)}.history-result small{display:block;font-weight:800;text-transform:uppercase}.history-result strong{display:block;margin-top:3px;font-size:1.08rem;overflow-wrap:anywhere}.history-card summary{cursor:pointer;color:#a75418;font-weight:800}.history-inputs{display:grid;grid-template-columns:1fr 1fr;gap:7px;margin-top:10px}.history-inputs div{padding:7px;border-radius:7px;background:#edf4f8}.history-inputs b,.history-inputs span{display:block}.history-inputs b{font-size:.7rem;color:#64748b}.history-inputs span{margin-top:2px;font-size:.85rem;color:#29465f;overflow-wrap:anywhere}@media(max-width:720px){.calc-history-head{align-items:flex-start;flex-direction:column}.calc-history-list,.history-inputs{grid-template-columns:1fr}.clear-history-btn{width:100%}}