:root{font-family:Inter,"Segoe UI","Microsoft YaHei",sans-serif;color:#253e38;background:#f5f7f5;font-synthesis:none}*{box-sizing:border-box}body{margin:0}header{height:82px;border-bottom:1px solid #dfe6e0;background:#fff;display:flex;align-items:center;justify-content:space-between;padding:0 6%}.brand{text-decoration:none;color:#243f37;font-size:21px;font-weight:700;display:flex;align-items:center;gap:12px}.brand-icon{background:#147563;color:white;border-radius:10px;padding:3px 10px;font-size:28px}.brand small{font-size:12px;letter-spacing:2px;margin-left:12px;color:#7b8983;font-weight:500}.header-note{font-size:14px;color:#7d8982}main{max-width:1120px;margin:0 auto;padding:30px 28px}.breadcrumb{font-size:14px;color:#7b8881}.breadcrumb span{padding:0 12px;color:#b6beb9}.heading{display:flex;align-items:center;justify-content:space-between;margin:30px 0}.eyebrow{font-size:12px;color:#22806e;letter-spacing:2px;font-weight:700;margin:0 0 10px}h1{font-size:32px;letter-spacing:-1px;margin:0 0 12px}.subtitle{font-size:16px;color:#758179;margin:0}.badge{border:1px solid #d9e6de;border-radius:20px;padding:8px 12px;color:#588371;font-size:13px;background:#fff}.badge i{display:inline-block;background:#369579;width:6px;height:6px;border-radius:100%;margin-right:7px}.workspace{display:grid;grid-template-columns:1.1fr 1fr;gap:24px}.input-panel,.result-panel{background:white;border:1px solid #dfe7e0;border-radius:16px;padding:28px 30px}.result-panel{background:#edf4ee;display:flex;flex-direction:column}.section-heading{display:flex;justify-content:space-between;align-items:center;margin-bottom:24px}h2{font-size:16px;margin:0;font-weight:600}.section-heading h2 span{font-size:12px;color:#8c9d91;font-weight:500;margin-right:12px}.reset{border:0;background:transparent;color:#6a7e72;font-size:14px;cursor:pointer}.shape-tabs{display:flex;gap:8px;background:#f3f6f3;padding:5px;border-radius:10px;margin-bottom:25px}.shape-tabs button{flex:1;background:transparent;border:1px solid transparent;border-radius:7px;padding:12px 0;font:inherit;font-size:15px;color:#7e8b81;cursor:pointer}.shape-tabs button[aria-pressed=true]{background:#fff;border-color:#ccdcd1;color:#146d59;box-shadow:0 2px 4px #223a2510}.shape-tabs b{font-size:20px;vertical-align:-1px;margin-right:9px}label{display:block;font-size:14px;margin:0 0 10px;color:#526559}select,input{font:inherit;font-size:16px;color:#304b3d}select{width:100%;background:#fff;border:1px solid #d8e0d9;border-radius:8px;padding:12px;cursor:pointer}input{width:100%;min-width:0;border:0;background:transparent;padding:12px 14px;outline:none}.input-wrap{display:flex;align-items:center;border:1px solid #d8e0d9;border-radius:8px;background:#fff}.input-wrap:focus-within{border-color:#25836a;box-shadow:0 0 0 3px #25836a14}.input-wrap>span{padding-right:14px;font-size:14px;color:#8a948b;white-space:nowrap}.density-row{display:flex;align-items:center;justify-content:space-between;margin-top:15px}.density-row label{margin:0}.compact{width:160px}.compact input{padding:8px 10px;font-size:14px}.hint{font-size:12px;line-height:1.8;color:#8a948b;margin:10px 0 0}.divider{height:1px;background:#e9eee8;margin:24px 0}.field-grid{display:grid;grid-template-columns:1fr 1fr;gap:18px;margin-bottom:22px}.length-wrap select{width:72px;border:0;padding:10px 6px;color:#798a7d;font-size:14px;background:transparent}.mode-row{display:flex;align-items:center;justify-content:space-between;margin-top:4px}.mode-row select{width:auto;border:0;font-size:13px;padding:0 0 10px;color:#27816a}.mode-row label{margin-bottom:10px}#tube-fields{margin-bottom:22px}.theoretical{font-size:12px;color:#7a9381;border:1px solid #cfdfd0;padding:4px 8px;border-radius:5px}.drawing{text-align:center;margin-top:-12px}.drawing svg{width:100%;height:178px;max-width:360px}.drawing svg text{fill:#6c8c7e;font-size:13px}.drawing>span{display:block;font-size:12px;color:#91a18f}.primary-result{text-align:center;padding:23px 0}.primary-result>span{font-size:14px;color:#60836d}.primary-result strong{font-size:54px;font-weight:600;letter-spacing:-2px;font-variant-numeric:tabular-nums;overflow-wrap:anywhere}.primary-result b{font-size:20px;font-weight:500;margin-left:10px;color:#60836d}.primary-result p{font-size:13px;color:#7d9481;margin:7px 0 0}.result-grid{display:grid;grid-template-columns:1fr 1fr;border-top:1px solid #d8e5d7;padding:22px 0;margin-top:auto}.result-grid>div+div{border-left:1px solid #d8e5d7;padding-left:25px}.result-grid span,.result-footer{font-size:13px;color:#7a8e7c}.result-grid p{font-size:13px;color:#718776;margin:10px 0 0;overflow-wrap:anywhere}.result-grid strong{font-size:23px;font-weight:500;color:#375945}.result-footer{display:flex;justify-content:space-between;border-top:1px solid #d8e5d7;padding-top:17px;gap:12px}.result-footer b{font-weight:500}.formula{display:flex;gap:18px;padding:24px 26px;border:1px solid #e0e7de;border-radius:12px;margin-top:24px;background:#f9faf7}.formula-icon{font-family:Georgia,serif;font-style:italic;font-size:27px;color:#779478}.formula h2{font-size:14px}.formula p:not(.hint){font-size:14px;color:#667965;margin:10px 0 0}footer{display:flex;justify-content:space-between;font-size:12px;color:#99a397;margin:24px 2px}.error{color:#b43e30;font-size:14px;line-height:1.6;background:#fff1ed;padding:10px;border-radius:6px}button:focus-visible,select:focus-visible,a:focus-visible{outline:2px solid #168269;outline-offset:3px}[hidden]{display:none!important}@media(max-width:760px){header{height:68px;padding:0 20px}.header-note,.brand small{display:none}main{padding:24px 18px}.workspace{grid-template-columns:1fr}.heading{margin:24px 0}h1{font-size:27px}.badge{display:none}.input-panel,.result-panel{padding:24px}.primary-result strong{font-size:48px}.formula{padding:20px}.field-grid{gap:12px}footer{gap:15px}}@media(prefers-reduced-motion:no-preference){button{transition:background .15s}}