.pimf-shell{--pimf-navy:#11364a;--pimf-teal:#087786;--pimf-cyan:#0b8fa0;--pimf-pale:#eef8f8;--pimf-amber:#a15d1d;background:#f7faf9;min-height:calc(100vh - 76px);padding-bottom:38px}.pimf-head{background:linear-gradient(118deg,#123247,#15586c 62%,#117787);color:#fff;padding:32px 0 40px}.pimf-back{color:#d8f1f3;text-decoration:none;font-weight:760;font-size:.9rem}.pimf-title-row{display:flex;justify-content:space-between;align-items:end;gap:34px;margin-top:18px}.pimf-head .eyebrow{color:#ffd0a6}.pimf-head h1{margin:4px 0 10px;max-width:900px;font-size:clamp(2.1rem,4.8vw,4rem);line-height:1.02;letter-spacing:-.045em}.pimf-head p{margin:0;max-width:790px;color:#dceff2;font-size:1.03rem}.pimf-board-switch{display:flex;flex:0 0 auto;background:rgba(255,255,255,.1);padding:5px;border:1px solid rgba(255,255,255,.28);border-radius:12px}.pimf-board-switch button{border:0;background:transparent;color:#eef9fa;font-weight:820;padding:9px 14px;border-radius:8px}.pimf-board-switch button.is-active{background:#fff;color:var(--pimf-navy)}.pimf-tabs{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));background:#fff;border:1px solid var(--line);border-top:0;overflow:hidden;box-shadow:0 8px 22px rgba(13,58,76,.06)}.pimf-tabs button{border:0;border-right:1px solid var(--line);background:#fff;padding:14px 10px;font-weight:800;color:#49606b}.pimf-tabs button:last-child{border-right:0}.pimf-tabs button span{display:block;font-size:.66rem;letter-spacing:.12em;color:#8a989e}.pimf-tabs button.is-active{background:#e8f6f8;color:var(--pimf-navy);box-shadow:inset 0 -3px 0 var(--cyan)}.pimf-session-bar{display:flex;align-items:center;margin:26px 0 14px;border-bottom:1px solid var(--line)}.pimf-session-bar>div{display:grid;min-width:112px;padding:0 18px 12px;border-right:1px solid var(--line)}.pimf-session-bar>div:first-child{padding-left:0}.pimf-session-bar small{font-size:.7rem;text-transform:uppercase;letter-spacing:.08em;color:#74838a;font-weight:800}.pimf-session-bar strong{color:var(--navy);font-size:1.02rem}.pimf-session-bar button{margin-left:auto;margin-bottom:11px;background:transparent;border:1px solid #91a7ad;border-radius:9px;padding:8px 12px;color:var(--navy);font-weight:750}.pimf-workspace{background:#fff;border:1px solid var(--line);padding:clamp(22px,4vw,42px);box-shadow:var(--shadow-soft);min-height:460px}.pimf-kicker{margin:0 0 7px;text-transform:uppercase;letter-spacing:.1em;font-weight:850;color:var(--teal2);font-size:.75rem}.pimf-question{margin:0 0 8px;color:var(--navy);font-size:clamp(1.65rem,3vw,2.45rem);line-height:1.12}.pimf-copy{max-width:830px;margin:0 0 24px;color:var(--muted)}.pimf-two-col{display:grid;grid-template-columns:minmax(0,1fr) minmax(340px,.82fr);gap:32px;align-items:start}.pimf-bond-stage{display:grid;place-items:center;min-height:245px;background:#f5faf9;border-top:1px solid #cddcda;border-bottom:1px solid #cddcda}.pimf-bond{display:flex;align-items:center;gap:14px;font-size:clamp(2rem,6vw,4rem);font-weight:850;color:var(--pimf-navy)}.pimf-bond-line{width:90px;height:3px;background:#526b73;position:relative}.pimf-bond-line:after{content:"";position:absolute;inset:-9px 0}.pimf-en-note{margin-top:12px;text-align:center;color:#718087;font-size:.78rem}.pimf-choice-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:11px;margin-top:18px}.pimf-choice{border:1px solid #aebfc4;background:#fff;padding:14px 15px;text-align:left;color:var(--navy);font-weight:760;min-height:58px}.pimf-choice:hover{background:#eef8f8;border-color:#75aab3}.pimf-choice.is-selected{border:2px solid var(--pimf-teal);background:#eaf7f7}.pimf-choice sub{font-size:.65em}.pimf-submit{margin-top:18px;border:0;border-radius:9px;padding:12px 18px;background:var(--teal);color:#fff;font-weight:820}.pimf-submit:disabled{opacity:.4;cursor:not-allowed}.pimf-molecule-card{border:1px solid #cadadd;background:#f8fbfb;padding:14px}.pimf-molecule-card>header{display:flex;justify-content:space-between;gap:16px;align-items:baseline;padding:2px 4px 8px}.pimf-molecule-card strong{color:var(--navy)}.pimf-molecule-card small{color:#73858b}.pimf-molecule-svg{display:block;width:100%;height:260px}.pimf-atom{fill:#fff;stroke:#15586c;stroke-width:1.7}.pimf-atom.is-central{fill:#dff1f3}.pimf-atom-label{fill:#11364a;font-size:6px;font-weight:800;text-anchor:middle;dominant-baseline:middle}.pimf-bond-svg{stroke:#526b73;stroke-width:1.3;stroke-linecap:round}.pimf-dipole{stroke:#b56422;stroke-width:1.1;stroke-linecap:round}.pimf-dipole-head{fill:#b56422}.pimf-dipole-plus{stroke:#b56422;stroke-width:1}.pimf-svg-caption{margin:5px 4px 0;color:#6f8289;font-size:.75rem;line-height:1.35}.pimf-polar-answer{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px;margin-top:16px}.pimf-reason-options{display:grid;gap:9px;margin-top:18px}.pimf-reason-options .pimf-choice{min-height:0}.pimf-force-panel{display:grid;grid-template-columns:minmax(250px,.58fr) minmax(0,1fr);gap:30px;align-items:center}.pimf-formula-block{display:grid;place-items:center;min-height:245px;background:#eff8f8;border:1px solid #c7dfe1}.pimf-formula-block strong{display:block;color:var(--pimf-navy);font-size:clamp(2.2rem,5vw,4.2rem);line-height:1}.pimf-formula-block span{display:block;margin-top:8px;color:#62757c;font-weight:720}.pimf-force-options{display:grid;gap:10px}.pimf-force-options label{display:flex;align-items:flex-start;gap:12px;padding:15px 16px;border:1px solid #b8c9cd;background:#fff;cursor:pointer}.pimf-force-options label:has(input:checked){border-color:#0b7181;background:#eaf7f6}.pimf-force-options input{margin-top:2px;width:19px;height:19px;accent-color:#0b7181}.pimf-force-options strong{display:block;color:var(--navy)}.pimf-force-options small{display:block;margin-top:2px;color:#687b82;line-height:1.35}.pimf-compare-grid{display:grid;grid-template-columns:1fr auto 1fr;gap:13px;align-items:stretch;margin:20px 0}.pimf-substance{display:grid;place-items:center;text-align:center;padding:25px 18px;background:#f6faf9;border:1px solid #ccd9d8;min-height:180px}.pimf-substance b{font-size:clamp(1.8rem,4vw,3rem);color:var(--pimf-navy)}.pimf-substance strong{margin-top:6px;color:#3f5963}.pimf-substance small{margin-top:10px;color:#718087}.pimf-versus{display:grid;place-items:center;color:#849399;font-weight:850}.pimf-compare-actions{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px;max-width:600px}.pimf-chain{margin-top:18px;border-left:3px solid #13808e;padding-left:18px}.pimf-chain h3{margin:0 0 9px;color:var(--navy);font-size:1rem}.pimf-chain ol{margin:0;padding-left:19px}.pimf-chain li{margin:8px 0;color:#415860}.pimf-chain li::marker{font-weight:800;color:#0b7181}.pimf-feedback,.pimf-explanation{margin-top:14px;padding:18px 20px}.pimf-feedback.is-good{background:#ecf8ef;border:1px solid #b9dfc1;color:#155b36}.pimf-feedback.is-bad{background:#fff2f0;border:1px solid #efc8c1;color:#832f2f}.pimf-feedback strong{display:block;font-size:1.04rem}.pimf-feedback span{display:block;margin-top:3px}.pimf-explanation{background:#f2f6f5;border:1px solid #d5dfdd;color:var(--ink)}.pimf-explanation h2{margin:0 0 9px;color:var(--navy);font-size:1.2rem}.pimf-explanation p{margin:7px 0}.pimf-hbond-stage{border-top:1px solid #cbd9d7;border-bottom:1px solid #cbd9d7;background:#f7fbfa;padding:8px 0}.pimf-hbond-svg{display:block;width:100%;height:300px}.pimf-hbond-atom{fill:#fff;stroke:#15586c;stroke-width:1.6;cursor:pointer;transition:.12s}.pimf-hbond-atom.is-clickable:hover{fill:#e2f5f6;stroke:#0b7181;stroke-width:2}.pimf-hbond-atom.is-selected{fill:#fff0d8;stroke:#a15d1d;stroke-width:2.2}.pimf-hbond-label{fill:#11364a;font-size:5.6px;font-weight:800;text-anchor:middle;dominant-baseline:middle;pointer-events:none}.pimf-hbond-line{stroke:#526b73;stroke-width:1.3}.pimf-hbond-interaction{stroke:#7a55a4;stroke-width:1.3;stroke-dasharray:3 3}.pimf-hbond-side-label{fill:#5e747b;font-size:4px;font-weight:700;text-anchor:middle}.pimf-hbond-instructions{display:flex;justify-content:space-between;gap:18px;align-items:start;margin-top:14px}.pimf-hbond-instructions ol{margin:0;padding-left:20px;color:#4c626a}.pimf-hbond-instructions li{margin:4px 0}.pimf-reset{border:1px solid #9db1b6;background:#fff;border-radius:8px;padding:8px 11px;color:var(--navy);font-weight:760}.pimf-connection{margin-top:13px;padding:12px 14px;background:#fff7e9;border:1px solid #e7d4ad;color:#684b1d}.pimf-board-note{margin-top:18px;padding:15px 18px;border-left:4px solid var(--teal);background:#eef7f7;color:#38535b}.pimf-board-note strong{color:var(--navy)}.pimf-rule-strip{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));margin-top:26px;border-top:1px solid #c8d7d5;border-left:1px solid #c8d7d5}.pimf-rule-strip article{padding:15px 17px;border-right:1px solid #c8d7d5;border-bottom:1px solid #c8d7d5;background:#fff}.pimf-rule-strip strong{display:block;color:var(--navy)}.pimf-rule-strip span{display:block;margin-top:4px;color:#667a81;font-size:.82rem;line-height:1.4}.pimf-foot{display:flex;justify-content:space-between;gap:20px;color:#7b898e;font-size:.78rem;padding:20px 2px 0}.pimf-foot a{color:#59737c}.pimf-numbers{display:flex;gap:9px;flex-wrap:wrap;margin-top:15px}.pimf-number{padding:7px 10px;background:#f3f7f6;border:1px solid #d5dfdd;color:#5d7077;font-size:.78rem}.pimf-number strong{color:var(--navy)}
@media(max-width:900px){.pimf-title-row{display:grid;align-items:start}.pimf-board-switch{justify-self:start}.pimf-tabs{grid-template-columns:repeat(3,1fr)}.pimf-tabs button:nth-child(3){border-right:0}.pimf-tabs button:nth-child(-n+3){border-bottom:1px solid var(--line)}.pimf-two-col,.pimf-force-panel{grid-template-columns:1fr}.pimf-molecule-card{order:-1}.pimf-rule-strip{grid-template-columns:1fr}.pimf-term{display:none}}
@media(max-width:620px){.pimf-head{padding-top:24px}.pimf-tabs{grid-template-columns:repeat(2,1fr)}.pimf-tabs button{border-bottom:1px solid var(--line)}.pimf-tabs button:nth-child(2n){border-right:0}.pimf-tabs button:last-child{grid-column:1/-1;border-bottom:0}.pimf-session-bar{flex-wrap:wrap;gap:8px;border-bottom:0}.pimf-session-bar>div{border:1px solid var(--line);padding:8px 10px;min-width:83px}.pimf-session-bar>div:first-child{padding-left:10px}.pimf-session-bar button{margin:0 0 0 auto}.pimf-workspace{padding:20px 16px;min-height:420px}.pimf-choice-grid,.pimf-polar-answer,.pimf-compare-actions{grid-template-columns:1fr}.pimf-compare-grid{grid-template-columns:1fr}.pimf-versus{min-height:25px}.pimf-hbond-svg{height:250px}.pimf-hbond-instructions{display:grid}.pimf-foot{display:grid}.pimf-molecule-svg{height:220px}}