:root{--bg:#0f1216;--panel:#151a21;--panel-2:#1b222b;--text:#e9eef5;--muted:#a9b4c2;--primary:#6ea8fe;--primary-600:#4a90ff;--ok:#25c2a0;--danger:#ff6b6b;--radius:14px;--shadow:0 10px 30px rgba(0,0,0,.35), 0 2px 10px rgba(0,0,0,.2)}*{box-sizing:border-box}html,body{height:100%}body{margin:0;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif,"Apple Color Emoji","Segoe UI Emoji";background:radial-gradient(1200px 600px at 10% -20%,#1e2530 0%,#0f1216 60%);color:var(--text);line-height:1.5}.cylinderTool{max-width:980px;margin:40px auto;padding:24px}.header{text-align:center;margin-bottom:16px}.header h1{margin:0 0 6px 0;font-size:clamp(22px,3.2vw,30px)}.subtitle{margin:0;color:var(--muted);font-size:14px}.panel{background:linear-gradient(180deg,var(--panel),var(--panel-2));border:1px solid rgba(255,255,255,.06);border-radius:var(--radius);padding:16px;box-shadow:var(--shadow);margin-bottom:14px}.calculator .row{padding:15px}@media (min-width:740px){.calculator .row{grid-template-columns:1fr 1fr}}label{display:flex;flex-direction:column;gap:8px}label span{color:var(--muted);font-size:13px}.inputUnit{display:grid;grid-template-columns:1fr max-content;gap:8px;align-items:center}input,select{background:#0e131a;color:var(--text);border:1px solid rgba(255,255,255,.08);border-radius:10px;padding:12px}select{padding-right:28px;min-width:84px;white-space:nowrap}.error{min-height:16px;color:var(--danger);font-size:12px}.resultBox{display:flex;flex-direction:column;justify-content:center;gap:6px;background:#0e131a;border:1px solid rgba(255,255,255,.08);border-radius:12px;padding:12px}.resultLabel{color:var(--muted);font-size:13px}.resultValue{font-weight:700;font-size:20px}.actions{display:flex;justify-content:flex-end}.primary,.secondary{padding:10px 14px;border-radius:12px;border:1px solid rgba(255,255,255,.1);background:#121821;color:var(--text);cursor:pointer}.primary{background:linear-gradient(180deg,#2a3a52,#1a2533);border-color:rgba(255,255,255,.16)}.primary:hover{filter:brightness(1.05)}.secondary:hover{background:#16202b;border-color:rgba(255,255,255,.18)}.panelHeader h2{margin:0 0 4px 0;font-size:20px}.panelHeader .muted{margin:0;color:var(--muted);font-size:14px}.exToolbar{display:flex;gap:12px;align-items:center;justify-content:space-between;margin:10px 0 12px}.exStats{color:var(--muted);font-size:14px;display:flex;gap:16px}.exerciseBody{display:grid;gap:12px}@media (min-width:740px){.exerciseBody{grid-template-columns:1fr 1fr}}.exParams{display:grid;gap:6px;color:#fff}.exInput{display:flex;gap:8px;align-items:flex-end}.exInput label{font-size:13px;color:var(--muted)}.exFeedback{min-height:18px;font-size:14px;margin-top:6px}.exFeedback.ok{color:var(--ok)}.exFeedback.err{color:var(--danger)}.visualization .vizWrap{display:block;width:100%;background:#0e131a;border:1px solid rgba(255,255,255,.08);border-radius:12px;padding:12px}.visualization svg{width:100%;height:auto;display:block}.vizLabel{fill:var(--muted);font-size:12px}.vizStroke{stroke:#6ea8fe;stroke-width:2;fill:none}.vizFill{fill:rgba(110,168,254,.18);stroke:#6ea8fe;stroke-width:1}.vizGuide{stroke:rgba(255,255,255,.15);stroke-dasharray:4 4;fill:none}.cylinderTool .panelHeader h2{color:var(--text)!important}.cylinderTool input::placeholder{color:var(--muted)!important;opacity:1!important}.cylinderTool input::-webkit-input-placeholder{color:var(--muted)!important;opacity:1!important}.cylinderTool input::-moz-placeholder{color:var(--muted)!important;opacity:1!important}.cylinderTool input:-ms-input-placeholder{color:var(--muted)!important;opacity:1!important}.cylinderTool input::-ms-input-placeholder{color:var(--muted)!important;opacity:1!important}span#volumeValue{color:#fff}