.tool-hero{background:linear-gradient(180deg,var(--surface),var(--white));padding:48px 0 38px;border-bottom:1px solid var(--border)}
.eyebrow{text-transform:uppercase;letter-spacing:.08em;font-size:12px;font-weight:800;color:var(--primary-dark);margin-bottom:10px}
.tool-hero h1{font-size:40px;max-width:780px;margin-bottom:12px}
.tool-intro{font-size:17px;max-width:780px;margin:0}
.calculator-section{padding:48px 0;background:var(--surface)}
.tool-layout{display:grid;grid-template-columns:minmax(0,1.55fr) minmax(260px,.7fr);gap:28px;align-items:start}
.calculator-card,.side-card{background:var(--white);border:1px solid var(--border);border-radius:12px;box-shadow:var(--shadow-sm)}
.calculator-card{padding:28px}
.card-heading h2,.side-card h2{font-size:21px;margin-bottom:8px}.card-heading p{font-size:14.5px;margin:0 0 24px}.card-heading code{background:var(--primary-tint);padding:2px 5px;border-radius:4px}
.ode-form{display:grid;grid-template-columns:1fr 1fr;gap:18px}.field{display:flex;flex-direction:column;gap:7px}.field.full{grid-column:1/-1}.field label{font-weight:700;font-size:14px}.field input{width:100%;padding:12px 13px;border:1px solid var(--border);border-radius:8px;background:var(--white);font:inherit;color:var(--ink);outline:none}.field input:focus{border-color:var(--primary);box-shadow:0 0 0 3px var(--primary-tint)}.field small{font-size:12.5px;color:var(--slate)}
.equation-input{display:flex;align-items:center;border:1px solid var(--border);border-radius:8px;overflow:hidden;background:var(--white)}.equation-input:focus-within{border-color:var(--primary);box-shadow:0 0 0 3px var(--primary-tint)}.equation-input span{padding:12px 0 12px 13px;font-weight:800}.equation-input input{border:0;border-radius:0;box-shadow:none!important}
.calculate-btn{margin-top:2px}.reset-btn{margin-top:2px}.form-note{grid-column:1/-1;font-size:12.5px;margin:0}.form-error{grid-column:1/-1;background:#fff2f2;border:1px solid #f0c8c8;color:#9d3333;border-radius:8px;padding:11px 13px;font-size:13.5px}
.result-panel{margin-top:28px;border-top:1px solid var(--border);padding-top:24px}.result-heading{display:flex;justify-content:space-between;align-items:center;gap:16px}.result-label{font-size:12px;text-transform:uppercase;letter-spacing:.06em;font-weight:800;color:var(--primary-dark);margin:0 0 4px}.result-heading h2{font-size:20px;margin:0}.result-method{font-size:12px;font-weight:800;background:var(--primary-tint);color:var(--primary-dark);padding:6px 9px;border-radius:999px}.table-wrap{overflow-x:auto;margin-top:16px;max-height:360px}.table-wrap table{width:100%;border-collapse:collapse;font-size:13.5px}.table-wrap th,.table-wrap td{text-align:right;padding:9px 12px;border-bottom:1px solid var(--border)}.table-wrap th{background:var(--surface);font-weight:800;color:var(--ink);position:sticky;top:0}.table-wrap td:first-child,.table-wrap th:first-child{text-align:left}
.tool-sidebar{display:grid;gap:18px}.side-card{padding:22px}.side-card h2{font-size:18px}.side-card p{font-size:14px}.check-list{list-style:disc;padding-left:20px;color:var(--slate);font-size:14px}.check-list li{margin:7px 0}.related-side a,.content-sidebar a{display:block;padding:11px 0;border-top:1px solid var(--border);font-size:14px;font-weight:700;color:var(--primary-dark)}.related-side a:first-of-type,.content-sidebar a:first-of-type{border-top:0}
.content-section{padding:72px 0}.content-grid{display:grid;grid-template-columns:minmax(0,1.55fr) minmax(260px,.7fr);gap:48px;align-items:start}.article-content h2{font-size:25px;margin:34px 0 10px}.article-content h2:first-child{margin-top:0}.article-content p{font-size:15.5px}.formula-box{background:var(--surface);border:1px solid var(--border);border-left:3px solid var(--primary);border-radius:10px;padding:20px;margin:24px 0}.formula-box h3{font-size:17px;margin-bottom:8px}.formula-box p{margin:4px 0}.faq-list{border-top:1px solid var(--border);margin-top:18px}.faq-list details{border-bottom:1px solid var(--border);padding:16px 0}.faq-list summary{cursor:pointer;font-weight:700}.faq-list details p{margin:10px 0 0;font-size:14.5px}.note-card{margin-top:18px;background:var(--surface)}
@media(max-width:900px){.tool-layout,.content-grid{grid-template-columns:1fr}.tool-sidebar{grid-template-columns:1fr 1fr}.content-sidebar{display:grid;grid-template-columns:1fr 1fr;gap:18px}.note-card{margin-top:0}}
@media(max-width:720px){.tool-hero{padding:38px 0 30px}.tool-hero h1{font-size:30px}.tool-intro{font-size:15.5px}.calculator-section,.content-section{padding:44px 0}.calculator-card{padding:20px}.ode-form{grid-template-columns:1fr}.field.full{grid-column:auto}.form-note,.form-error{grid-column:auto}.tool-sidebar,.content-sidebar{display:block}.side-card{margin-top:16px}.result-heading{align-items:flex-start}.article-content h2{font-size:22px}.article-content p{font-size:15px}}