/* ════════════════════════════════════════════════════════════════════════
   CALCULATRICE & SOLVEUR LANXAS (gratuit) — portail éducation
   Identité LANXAS : bleus, blanc, gris très clair + fines lignes dorées.
   Accessibilité RGAA/WCAG : focus visible, aria-live, contrastes, reduced-motion.
   Préfixe .clx- pour ne jamais entrer en conflit avec le reste du site.
   ════════════════════════════════════════════════════════════════════════ */
:root{
  --clx-navy:#1A2A6C; --clx-navy2:#0d1a4a; --clx-blue:#1d4ed8; --clx-blue2:#1e40af;
  --clx-ink:#16213f; --clx-gray:#5a6680; --clx-line:#e7ecf7;
  --clx-bg:#f4f7fd; --clx-bg2:#eef3fc; --clx-card:#ffffff; --clx-soft:#f0f5ff;
  --clx-gold1:#c9a23f; --clx-gold2:#f4e6ad; --clx-gold3:#b8862b;
  --clx-goldline:linear-gradient(90deg,transparent,var(--clx-gold1) 14%,var(--clx-gold2) 50%,var(--clx-gold1) 86%,transparent);
  --clx-shadow:0 14px 40px -16px rgba(26,42,108,.22);
  --clx-r:16px;
}
.clx{position:relative;font-family:'Inter',system-ui,sans-serif;color:var(--clx-ink);padding-top:60px;min-height:100vh;
  background:radial-gradient(1100px 420px at 82% -60px,#e9f0ff 0%,rgba(233,240,255,0) 62%),radial-gradient(900px 380px at 0% 120px,#eef3fe 0%,rgba(238,243,254,0) 55%),linear-gradient(180deg,#f8fafe 0%,var(--clx-bg) 100%);}
.clx *{box-sizing:border-box}

/* ─── Accessibilité ─── */
.clx-skip{position:absolute;left:-999px;top:0;z-index:5000;background:var(--clx-navy);color:#fff;padding:10px 16px;border-radius:0 0 10px 0;font-weight:700;text-decoration:none}
.clx-skip:focus{left:0}
.clx :focus-visible{outline:3px solid var(--clx-blue);outline-offset:2px;border-radius:6px}
.clx-sr{position:absolute!important;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}
@media (prefers-reduced-motion:reduce){.clx *,.clx *::before,.clx *::after{animation:none!important;transition:none!important}}

/* ─── Lignes dorées ─── */
.clx-gold-rule{height:1px;width:100%;background:var(--clx-goldline);opacity:.9}

/* ════════════ HERO ════════════ */
.clx-hero{position:relative;text-align:center;padding:46px 20px 8px;overflow:hidden}
.clx-hero::before{content:"";position:absolute;inset:0;background:radial-gradient(540px 200px at 50% -40px,rgba(29,78,216,.08),transparent 70%);pointer-events:none}
.clx-eyebrow{display:inline-flex;align-items:center;gap:10px;font-size:11px;font-weight:700;letter-spacing:3px;text-transform:uppercase;color:var(--clx-gold3);margin-bottom:14px}
.clx-eyebrow span.l{width:34px;height:1px;background:var(--clx-goldline)}
.clx-hero h1{font-size:clamp(1.8rem,4.2vw,3rem);font-weight:800;line-height:1.07;letter-spacing:-.02em;color:var(--clx-navy2);margin:0}
.clx-hero h1 .g{background:linear-gradient(90deg,var(--clx-gold3),var(--clx-gold1) 45%,var(--clx-gold2) 70%,var(--clx-gold3));-webkit-background-clip:text;background-clip:text;color:transparent}
.clx-hero p{max-width:620px;margin:14px auto 0;font-size:clamp(14px,1.6vw,16px);line-height:1.7;color:var(--clx-gray)}

/* ════════════ BARRE PRINCIPALE (calcul + IA) ════════════ */
.clx-wrap{max-width:1120px;margin:0 auto;padding:18px 20px 70px}
.clx-search{background:var(--clx-card);border:1px solid var(--clx-line);border-radius:20px;box-shadow:var(--clx-shadow);padding:18px;position:relative;overflow:hidden}
.clx-search::before{content:"";position:absolute;left:0;right:0;top:0;height:2px;background:var(--clx-goldline)}
.clx-inputrow{display:flex;gap:12px;align-items:stretch}
.clx-inwrap{flex:1;position:relative;display:flex;align-items:center}
.clx-inwrap>svg{position:absolute;left:16px;width:22px;height:22px;color:var(--clx-blue);pointer-events:none}
.clx-input{width:100%;border:1px solid var(--clx-line);border-radius:14px;background:#fbfdff;
  font-family:'Inter',sans-serif;font-size:clamp(16px,2vw,21px);font-weight:500;color:var(--clx-ink);
  padding:18px 18px 18px 50px;transition:all .16s}
.clx-input::placeholder{color:#9aa6c0;font-weight:400}
.clx-input:focus{outline:none;border-color:var(--clx-blue);background:#fff;box-shadow:0 0 0 4px rgba(29,78,216,.12)}
.clx-kbtoggle{flex-shrink:0;width:56px;border:1px solid var(--clx-line);background:#fff;border-radius:14px;cursor:pointer;color:var(--clx-navy);display:flex;align-items:center;justify-content:center;transition:all .15s}
.clx-kbtoggle:hover{background:var(--clx-soft);border-color:#c7d3f0;color:var(--clx-blue)}
.clx-kbtoggle svg{width:24px;height:24px}

/* Actions (Calculer + opérations) */
.clx-actions{display:flex;flex-wrap:wrap;gap:8px;margin-top:14px;align-items:center}
.clx-go{display:inline-flex;align-items:center;gap:8px;font-family:inherit;font-size:15px;font-weight:700;cursor:pointer;border-radius:12px;padding:13px 24px;border:none;color:#fff;
  background:linear-gradient(135deg,var(--clx-navy) 0%,var(--clx-blue) 100%);box-shadow:0 10px 24px -10px rgba(29,78,216,.7);position:relative;overflow:hidden;transition:all .18s}
.clx-go::after{content:"";position:absolute;left:0;right:0;top:0;height:1px;background:var(--clx-goldline);opacity:.7}
.clx-go:hover{transform:translateY(-2px)}
.clx-go svg{width:18px;height:18px}
.clx-op{font-family:inherit;font-size:13px;font-weight:600;cursor:pointer;border:1px solid var(--clx-line);background:#fff;color:var(--clx-navy);border-radius:999px;padding:9px 15px;transition:all .15s}
.clx-op:hover{border-color:#c7d3f0;background:var(--clx-soft);color:var(--clx-blue);transform:translateY(-1px)}
.clx-sep{flex-basis:100%;height:0}

/* Bouton IA */
.clx-ai{display:inline-flex;align-items:center;gap:9px;margin-left:auto;font-family:inherit;font-size:13.5px;font-weight:700;text-decoration:none;
  color:var(--clx-navy);background:#fff;border:1px solid var(--clx-gold1);border-radius:12px;padding:11px 17px;transition:all .16s}
.clx-ai:hover{background:linear-gradient(135deg,#fffaf0,#fdf3d8);transform:translateY(-1px)}
.clx-ai svg{width:18px;height:18px;color:var(--clx-gold3)}
@media(max-width:640px){.clx-ai{margin-left:0;width:100%;justify-content:center}}

/* Clavier mathématique */
.clx-keyboard{margin-top:14px;border-top:1px solid var(--clx-line);padding-top:14px;display:none;grid-template-columns:repeat(auto-fill,minmax(54px,1fr));gap:7px}
.clx-keyboard.open{display:grid}
.clx-key{font-family:'Inter',sans-serif;font-size:15px;font-weight:600;color:var(--clx-navy);background:var(--clx-soft);border:1px solid var(--clx-line);border-radius:10px;padding:11px 0;cursor:pointer;transition:all .12s}
.clx-key:hover{background:#fff;border-color:var(--clx-blue);color:var(--clx-blue)}
.clx-key.wide{grid-column:span 2}

/* ════════════ RÉSULTAT ════════════ */
.clx-result{margin-top:16px;background:var(--clx-card);border:1px solid var(--clx-line);border-radius:18px;box-shadow:var(--clx-shadow);padding:0;display:none;overflow:hidden}
.clx-result.show{display:block}
.clx-result .top{height:2px;background:var(--clx-goldline)}
.clx-result-in{padding:20px 22px 22px}
.clx-rlabel{font-size:11px;font-weight:700;letter-spacing:1px;text-transform:uppercase;color:var(--clx-gray);margin:0 0 6px;display:flex;align-items:center;gap:8px}
.clx-rin{font-size:15px;color:var(--clx-gray);padding:8px 0;border-bottom:1px dashed var(--clx-line);margin-bottom:14px;overflow-x:auto}
.clx-rout{font-size:clamp(20px,3vw,30px);font-weight:700;color:var(--clx-navy2);overflow-x:auto;line-height:1.4}
.clx-rout .katex{font-size:1.15em}
.clx-rnote{margin-top:14px;font-size:13px;color:var(--clx-gray);line-height:1.6;display:flex;gap:8px;align-items:flex-start}
.clx-rnote svg{width:15px;height:15px;color:var(--clx-blue);flex-shrink:0;margin-top:2px}
.clx-rerror{color:#be123c;font-size:14.5px;font-weight:600;display:flex;align-items:center;gap:8px}
.clx-graph-wrap{margin-top:16px;border:1px solid var(--clx-line);border-radius:12px;background:#fff;padding:10px;display:none}
.clx-graph-wrap.show{display:block}
.clx-graph-wrap canvas{display:block;width:100%;height:auto;border-radius:8px}
.clx-graph-wrap svg{display:block;margin:0 auto;max-width:100%;border-radius:8px}
.clx-graph-wrap .function-plot text{font-family:'Inter',sans-serif;fill:#5a6680;font-size:11px}
.clx-graph-wrap .function-plot .top-right-legend text{fill:var(--clx-navy)}
.clx-graph-wrap .function-plot .x.axis path,.clx-graph-wrap .function-plot .y.axis path,.clx-graph-wrap .function-plot .domain{stroke:#9aa6c0}
.clx-graph-wrap .function-plot .tick line{stroke:#eef2fb;opacity:1}
.clx-graph-wrap .function-plot .origin{stroke:#9aa6c0}
.clx-rcopy{margin-top:14px}
.clx-copy{font-family:inherit;font-size:12.5px;font-weight:600;cursor:pointer;border:1px solid var(--clx-line);background:#fff;color:var(--clx-navy);border-radius:9px;padding:8px 13px;display:inline-flex;align-items:center;gap:7px;transition:all .15s}
.clx-copy:hover{border-color:var(--clx-blue);color:var(--clx-blue);background:var(--clx-soft)}
.clx-copy svg{width:14px;height:14px}

/* ════════════ CATÉGORIES (façon Wolfram) ════════════ */
.clx-secttitle{display:flex;align-items:center;gap:12px;margin:42px 0 18px}
.clx-secttitle h2{font-size:15px;font-weight:800;letter-spacing:.5px;text-transform:uppercase;color:var(--clx-navy);white-space:nowrap}
.clx-secttitle .line{flex:1;height:1px;background:var(--clx-goldline);opacity:.7}
.clx-cats{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:16px}
.clx-cat{background:var(--clx-card);border:1px solid var(--clx-line);border-radius:var(--clx-r);padding:18px 18px 12px;transition:box-shadow .2s,transform .2s,border-color .2s}
.clx-cat:hover{box-shadow:var(--clx-shadow);border-color:#d6e0f5;transform:translateY(-3px)}
.clx-cat-h{display:flex;align-items:center;gap:11px;margin-bottom:12px;padding-bottom:11px;border-bottom:1px solid var(--clx-line)}
.clx-cat-ico{width:40px;height:40px;border-radius:11px;background:linear-gradient(135deg,#eef4ff,#e6eeff);border:1px solid #e3ebf9;display:flex;align-items:center;justify-content:center;flex-shrink:0}
.clx-cat-ico svg{width:22px;height:22px;color:var(--clx-blue)}
.clx-cat-h h3{font-size:15px;font-weight:800;color:var(--clx-navy2);margin:0}
.clx-cat-h p{font-size:11.5px;color:var(--clx-gray);margin:2px 0 0}
.clx-ex{display:flex;flex-direction:column;gap:2px}
.clx-exbtn{display:flex;align-items:center;gap:10px;width:100%;text-align:left;font-family:inherit;font-size:13.5px;color:var(--clx-ink);background:none;border:none;border-radius:9px;padding:9px 10px;cursor:pointer;transition:background .14s,color .14s}
.clx-exbtn:hover{background:var(--clx-soft);color:var(--clx-blue)}
.clx-exbtn code{font-family:'SFMono-Regular',Consolas,monospace;font-size:12.5px;color:var(--clx-navy);background:var(--clx-bg2);border-radius:6px;padding:2px 7px;flex:1}
.clx-exbtn .arr{color:var(--clx-gold3);font-weight:700;flex-shrink:0}

/* ════════════ ACCÈS RAPIDE (tout sous la main) ════════════ */
.clx-tiles{display:grid;grid-template-columns:repeat(auto-fill,minmax(244px,1fr));gap:16px}
.clx-tile{position:relative;display:flex;flex-direction:column;gap:8px;text-decoration:none;background:linear-gradient(135deg,var(--clx-navy) 0%,var(--clx-blue2) 100%);color:#fff;border-radius:var(--clx-r);padding:22px 20px;overflow:hidden;min-height:130px;transition:transform .2s,box-shadow .2s}
.clx-tile::before{content:"";position:absolute;left:0;right:0;top:0;height:2px;background:var(--clx-goldline)}
.clx-tile:hover{transform:translateY(-4px);box-shadow:0 18px 40px -16px rgba(13,26,74,.6)}
.clx-tile.alt{background:var(--clx-card);color:var(--clx-navy2);border:1px solid var(--clx-line)}
.clx-tile-ico{width:44px;height:44px;border-radius:12px;background:rgba(255,255,255,.14);display:flex;align-items:center;justify-content:center;margin-bottom:4px}
.clx-tile.alt .clx-tile-ico{background:var(--clx-soft)}
.clx-tile-ico svg{width:24px;height:24px;color:#fff}
.clx-tile.alt .clx-tile-ico svg{color:var(--clx-blue)}
.clx-tile h3{font-size:16px;font-weight:800;margin:0}
.clx-tile p{font-size:12.5px;line-height:1.5;margin:0;opacity:.9}
.clx-tile .go{margin-top:auto;font-size:12.5px;font-weight:700;display:inline-flex;align-items:center;gap:6px}
.clx-tile.alt .go{color:var(--clx-blue)}

/* Bandeau version gratuite / payante */
.clx-promo{margin-top:42px;background:linear-gradient(135deg,#fbfdff,#eef4ff);border:1px solid var(--clx-line);border-radius:var(--clx-r);padding:22px 24px;display:flex;align-items:center;gap:18px;flex-wrap:wrap}
.clx-promo .t{flex:1;min-width:220px}
.clx-promo h3{font-size:16px;font-weight:800;color:var(--clx-navy2);margin:0 0 5px}
.clx-promo p{font-size:13.5px;color:var(--clx-gray);line-height:1.6;margin:0}
.clx-promo .btns{display:flex;gap:10px;flex-wrap:wrap}
.clx-promo a{text-decoration:none;font-size:13.5px;font-weight:700;border-radius:11px;padding:11px 18px;transition:all .16s}
.clx-promo a.p{background:linear-gradient(135deg,var(--clx-navy),var(--clx-blue));color:#fff}
.clx-promo a.p:hover{transform:translateY(-2px)}
.clx-promo a.s{background:#fff;border:1px solid var(--clx-line);color:var(--clx-navy)}
.clx-promo a.s:hover{border-color:var(--clx-blue);color:var(--clx-blue)}

@media(max-width:640px){
  .clx-hero{padding:32px 16px 6px}
  .clx-wrap{padding:14px 14px 56px}
  .clx-search{padding:14px}
  .clx-inputrow{flex-wrap:wrap}
  .clx-kbtoggle{width:100%;height:46px}
}