:root{font-family:system-ui,-apple-system,'Segoe UI',Arial,sans-serif;color:#192b3f;background:#f4f7fb}*{box-sizing:border-box}body{margin:0}h1{font-size:clamp(1.7rem,3vw,2.1rem);margin:0 0 10px}h2{font-size:1.25rem;margin:0 0 17px;color:#183e65}h3{font-size:1.03rem;color:#214d78;margin:0 0 10px}.page{max-width:1100px;margin:0 auto;padding:24px 16px}.introduction p{line-height:1.7;max-width:900px;color:#4c5d70;margin:0 0 23px}.panel{background:#fff;border:1px solid #dbe6f0;border-radius:13px;padding:23px;margin:0 0 20px;box-shadow:0 3px 13px #1c365007}.panel p{line-height:1.65}.inputs{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:12px}.inputs .function-input{grid-column:span 3}.inputs label{display:block;font-size:.9rem;font-weight:650;min-width:0}.inputs input,.choice select{display:block;width:100%;padding:11px 10px;margin-top:7px;border:1px solid #b5c8d9;border-radius:8px;background:#fff;font:inherit;color:#1c344d}.inputs input:focus,.choice select:focus{outline:2px solid #6ba5d8;outline-offset:1px}.actions{display:flex;gap:10px;flex-wrap:wrap;margin-top:17px}button{border:0;border-radius:8px;padding:11px 16px;background:#1767a8;color:white;font:inherit;font-weight:650;cursor:pointer}button:hover:not(:disabled){filter:brightness(1.09)}button.secondary{background:#e6edf5;color:#1b4569}button:disabled{opacity:.43;cursor:default}.hint{font-size:.9rem;color:#526779;margin:12px 0 0}.hint code{background:#eef3f9;padding:1px 4px;border-radius:3px;color:#143b60}.message{margin:17px 0 0;border-left:4px solid #4483ba;background:#f0f7ff;border-radius:5px;padding:12px 14px;color:#174165}.message.error{background:#fff3f2;color:#8d2c2b;border-color:#bf4240}.choice{max-width:670px}.choice label{font-weight:650}.choice select{margin-top:6px}.analysis-grid{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin-top:17px}.subpanel{background:#f7faff;border:1px solid #e4edf6;border-radius:10px;padding:17px;min-width:0}.subpanel p:last-child{margin-bottom:0}.equation{padding:10px 4px;overflow-x:auto;overflow-y:hidden;font-size:1.04rem;min-height:36px}.equation mjx-container{max-width:100%;overflow-x:auto;overflow-y:hidden}.formula-text{font-size:.86rem;color:#597086;overflow-wrap:anywhere;margin:5px 0}.proof-status{font-weight:750}.proof-status.good{color:#186747}.proof-status.bad{color:#a24333}.proof-status.unknown{color:#73521d}.metric-line{font-size:.92rem;color:#435c74}.graph{width:100%;background:#fff;border:1px solid #e4eaf2;border-radius:8px;overflow:hidden}.graph svg{display:block;width:100%;height:auto}.legend{display:flex;flex-wrap:wrap;gap:16px;margin-top:12px;color:#526677;font-size:.9rem}.legend>span{display:inline-flex;gap:7px;align-items:center}.legend-line{width:24px;height:0;border-top:3px solid}.legend-line.blue{border-color:#2169b9}.legend-line.gray{border-color:#6c7f93;border-top-style:dashed}.legend-line.orange{border-color:#e58122}.action-steps{margin:20px 0 10px}.table-scroll{width:100%;overflow:auto}table{width:100%;border-collapse:collapse;min-width:750px;font-size:.9rem}th,td{padding:10px 12px;border-bottom:1px solid #e2eaf3;text-align:right;white-space:nowrap}th{color:#254768;background:#edf4fb;font-weight:700}tr.visible{background:#e6f3ff}tr{cursor:pointer}tbody tr:hover{background:#f4f8fc}.summary{padding:12px 15px;background:#f5f8fc;border-radius:7px;margin:16px 0 0}.educational h3{margin-top:23px}.educational p{color:#35485c}.educational .equation{text-align:center}footer{text-align:center;padding:12px 0 30px;font-size:.9rem;color:#627589}footer a{color:#1767a8}@media(max-width:860px){.inputs{grid-template-columns:repeat(3,minmax(0,1fr))}.inputs .function-input{grid-column:span 3}}@media(max-width:700px){.analysis-grid{grid-template-columns:1fr}.panel{padding:17px}.inputs{grid-template-columns:repeat(2,minmax(0,1fr))}.inputs .function-input{grid-column:span 2}}@media(max-width:480px){.inputs{grid-template-columns:1fr}.inputs .function-input{grid-column:span 1}.actions button{flex:1}.page{padding:18px 12px}.panel{padding:14px}}

.derivative{font-size:.93rem;padding:5px 0;min-height:26px}

/* v1.01: scelta esplicita di g(x), incluse trasformazioni personali */
.choice-help{margin:3px 0 10px;color:#495c70}
.candidate-fieldset{border:0;padding:0;margin:0;min-width:0}
.candidate-fieldset legend{font-size:.92rem;font-weight:700;margin-bottom:11px;color:#214d78}
.candidate-options{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:11px}
.candidate-item{display:flex;align-items:flex-start;gap:11px;border:1px solid #bdcbda;border-radius:9px;padding:12px;background:#fff;cursor:pointer;min-width:0}
.candidate-item:hover{border-color:#377cb7;background:#f5faff}
.candidate-item.is-selected,.candidate-item:has(input:checked){border:2px solid #2069ad;background:#edf6ff;padding:11px}
.candidate-item:focus-within{outline:2px solid #6ba5d8;outline-offset:2px}
.candidate-item>input{margin-top:4px;accent-color:#1668ae;flex-shrink:0;width:17px;height:17px}
.candidate-body{min-width:0;display:flex;flex-direction:column;gap:4px;width:100%}
.candidate-heading{font-size:.9rem;font-weight:650;color:#264663}
.candidate-math{font-size:1rem;color:#0f3f68;overflow-x:auto;max-width:100%;padding:2px 0;min-height:28px}
.candidate-status{font-size:.79rem;font-weight:650;color:#56687a}
.candidate-status.good{color:#186747}.candidate-status.bad{color:#a24333}.candidate-status.unknown{color:#73521d}
.custom-box{background:#f7faff;border:1px solid #dce7f2;padding:15px;border-radius:9px;margin-top:16px}
.custom-box>label{font-weight:700;display:block;color:#214d78;margin-bottom:9px}
.custom-line{display:flex;gap:9px;align-items:stretch}
.custom-line input{min-width:0;flex:1;font:inherit;padding:10px 12px;border:1px solid #b5c8d9;border-radius:8px;color:#1c344d;background:white}
.custom-line input:focus{outline:2px solid #6ba5d8;outline-offset:1px}
.custom-line button{white-space:nowrap}
@media(max-width:700px){.candidate-options{grid-template-columns:1fr}}
@media(max-width:470px){.custom-line{flex-direction:column}.custom-line button{width:100%}}

/* v1.02: gli estremi a e b formano un'unica coppia, mai spezzata su righe diverse. */
.inputs{grid-template-columns:repeat(12,minmax(0,1fr));column-gap:12px;row-gap:13px}
.inputs .function-input{grid-column:span 6}
.inputs .x0-input{grid-column:span 2}
.inputs .interval-pair{grid-column:span 4;display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px;min-width:0;align-items:end}
.inputs .interval-pair label{min-width:0}
.inputs .tol-input,.inputs .max-input{grid-column:span 3}
.inputs input{min-width:0}
/* Il riquadro inferiore e le formule rimangono leggibili anche su laptop piccoli. */
.candidate-math{overflow-wrap:anywhere}
.candidate-math mjx-container{max-width:100%;overflow-x:auto;overflow-y:hidden}
@media(max-width:850px){
 .inputs{grid-template-columns:repeat(12,minmax(0,1fr))}
 .inputs .function-input{grid-column:span 12}
 .inputs .x0-input{grid-column:span 4}
 .inputs .interval-pair{grid-column:span 8}
 .inputs .tol-input,.inputs .max-input{grid-column:span 6}
}
@media(max-width:480px){
 .inputs{grid-template-columns:repeat(2,minmax(0,1fr))}
 .inputs .function-input,.inputs .x0-input,.inputs .interval-pair{grid-column:span 2}
 .inputs .tol-input,.inputs .max-input{grid-column:span 1}
 .inputs .interval-pair{gap:10px}
}

/* v1.03: isolamenti algebrici in primo piano; rilassamenti in un gruppo espandibile. */
.group-heading{font-size:.96rem;margin:12px 0 9px;color:#214d78}
.relaxation-details{border:1px solid #d5e3f1;border-radius:9px;padding:12px;margin-top:16px;background:#f7faff}
.relaxation-details>summary{cursor:pointer;font-weight:700;color:#1d527e;padding:3px 2px}
.relaxation-details>summary:focus-visible{outline:2px solid #236cae;outline-offset:3px}
.relaxation-details>.hint{margin:9px 0 13px}
.explanation{color:#334c66;font-size:.92rem;margin:9px 0}
.transform-warning{border-left:3px solid #bb873b;background:#fff6e9;padding:9px 11px;border-radius:4px;font-size:.86rem;color:#704711}

.candidate-trial{font-size:.79rem;color:#536d80;line-height:1.35}

/* v1.04: passaggi matematici e diagnostica degli zeri, senza affollare le opzioni. */
.verification-panel{margin-top:15px;border:1px solid #dce7f2;background:#fbfdff;border-radius:9px;padding:15px}
.verification-panel h3{margin-bottom:5px}.math-steps{display:grid;grid-template-columns:repeat(auto-fit,minmax(min(100%,280px),1fr));gap:6px 14px}
.math-step{min-width:0;overflow-x:auto;padding:3px 5px;color:#163f67}
.math-step mjx-container{max-width:100%;overflow-x:auto;overflow-y:hidden}
.equivalence-note{font-weight:650;color:#284c6c;margin:7px 0 4px}
.roots-note{font-size:.89rem;color:#52677a;margin:4px 0 1px}
.local-convergence{border-left:3px solid #4a81ae;background:#f3f8fd;border-radius:4px;padding:9px 12px;font-size:.9rem;color:#34516b}


/* v1.05: esito del controllo sulla funzione originale, distinto dal solo punto fisso. */
.iteration-outcome{margin:14px 0 10px;padding:12px 14px;border-radius:7px;border-left:4px solid #7b8ba1;background:#f5f8fd;color:#344a61;line-height:1.55;font-size:.93rem}
.iteration-outcome.error{border-color:#bc4741;background:#fff1ef;color:#8a302b;font-weight:650}
.iteration-outcome.success{border-color:#38916d;background:#eef9f2;color:#225c43}
.iteration-outcome.caution{border-color:#bc9147;background:#fff8e9;color:#76541c}
.candidate-extra{font-size:.79rem;color:#9b3933;font-weight:650;line-height:1.4}

/* v1.06: preferenza esplicita, guardie di ramo, radici e falsi punti fissi. */
.suggestion-note{margin:10px 0 12px;padding:9px 12px;border-left:3px solid #4f87bb;background:#f2f8fe;border-radius:5px;font-size:.87rem;color:#2f526f}
.candidate-recommended{display:inline-block;margin-left:8px;background:#e2f3eb;border-radius:4px;padding:2px 6px;color:#196548;font-size:.75rem;font-weight:700;vertical-align:middle}
.candidate-guard{display:block;color:#76551b;font-size:.79rem;line-height:1.4;font-weight:650}
.candidate-guard.invalid{color:#a33131}
.branch-condition{background:#fff8e9;border-left:3px solid #b88935;padding:9px 11px;border-radius:5px;font-size:.87rem;color:#6c4e1f;line-height:1.6}
.branch-condition.invalid{background:#fff0ef;border-color:#b44040;color:#8b3330}
.graph-marker-note{font-size:.83rem;color:#576b80;margin:8px 0 0!important}
.legend-point{width:13px;height:13px;border:2.5px solid;border-radius:50%;display:inline-block;background:#fff;flex-shrink:0}
.legend-point.green{border-color:#17805a}.legend-point.red{border-color:#b33b40}.legend-point.amber{border-color:#b78222;border-style:dashed}

/* v1.07: punto corrente distinto dalle radici e avviso di uscita da [a,b]. */
.legend-diamond{width:12px;height:12px;display:inline-block;background:#246aab;transform:rotate(45deg);border:2px solid white;box-shadow:0 0 0 1px #246aab;flex-shrink:0;margin:0 4px}
.interval-warning{padding:12px 14px;border-radius:7px;border-left:4px solid #b98426;background:#fff8e9;color:#73501c;font-size:.93rem;line-height:1.6;margin:10px 0}
tr.row-outside td{color:#854d14;background:#fff8ed}
tr.row-outside.visible td{background:#fceac9}

/* v1.08: opzioni di visualizzazione del grafico, indipendenti dai calcoli. */
.graph-controls{display:flex;flex-wrap:wrap;gap:10px 23px;align-items:center;min-width:0;margin:1px 0 12px;padding:9px 12px 11px;border:1px solid #dbe6f1;border-radius:8px;background:#f9fbfe}
.graph-controls legend{padding:0 5px;color:#214d78;font-size:.88rem;font-weight:700}
.graph-controls label{display:inline-flex;align-items:center;gap:7px;font-size:.87rem;color:#36536c;cursor:pointer}
.graph-controls input{width:17px;height:17px;accent-color:#1a6cac;cursor:pointer}
.suggestion-note.no-recommendation{background:#fff7e9;border-left-color:#bb8937;color:#6e4d1c}
@media(max-width:480px){.graph-controls{gap:9px 12px}.graph-controls label{width:100%}}

/* v1.12 beta: riepilogo zeri e destinazione delle trasformazioni. */
.root-overview{margin:0 0 14px;padding:11px 13px;border:1px solid #d7e4f1;border-radius:8px;background:#f6f9fc;color:#294b68;font-size:.88rem;line-height:1.65}
.candidate-destination{font-size:.81rem;color:#205e54;font-weight:600;line-height:1.4}