/* Identité graphique commune : modifier ce fichier pour personnaliser les couleurs. */
:root{--bg:#091425;--surface:#122238;--surface2:#182c46;--text:#edf4ff;--muted:#b6c8dc;--line:#334963;--accent:#70efc0;--accent2:#80aeff;--radius:18px;--max:1120px;color-scheme:dark}*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:radial-gradient(ellipse at 75% -5%,#1a3558 0,transparent 45%),var(--bg);color:var(--text);font:16px/1.58 system-ui,-apple-system,Segoe UI,sans-serif;min-height:100vh}a{color:var(--accent2)}a:hover{color:var(--accent)}button,input{font:inherit}button{cursor:pointer}button:disabled{opacity:.5;cursor:not-allowed}.container{width:min(var(--max),calc(100% - 36px));margin:auto}.topbar{border-bottom:1px solid var(--line);background:#0b1829e8;position:sticky;top:0;z-index:5;backdrop-filter:blur(12px)}.nav{min-height:70px;display:flex;align-items:center;justify-content:space-between;gap:20px}.brand{color:var(--text);font-weight:850;letter-spacing:-.04em;text-decoration:none;font-size:1.2rem}.brand span{color:var(--accent)}.navlinks{display:flex;align-items:center;gap:18px;flex-wrap:wrap}.navlinks a{font-size:.92rem;text-decoration:none;color:var(--muted)}.navlinks a:hover{color:var(--text)}.hero{padding:76px 0 45px}.eyebrow{letter-spacing:.17em;text-transform:uppercase;font-size:.8rem;font-weight:800;color:var(--accent)}h1{font-size:clamp(2.2rem,5.8vw,4.6rem);letter-spacing:-.055em;line-height:1.08;margin:14px 0 20px}h2{font-size:clamp(1.4rem,3vw,2rem);line-height:1.18;letter-spacing:-.03em;margin:0 0 18px}h3{margin:0 0 8px;font-size:1.1rem}p{margin:0 0 16px}.lead{font-size:1.12rem;color:var(--muted);max-width:720px}.pill{display:inline-flex;align-items:center;gap:6px;border:1px solid #3c5774;border-radius:40px;padding:5px 11px;color:var(--muted);font-size:.78rem;font-weight:750}.stats{display:flex;gap:20px;flex-wrap:wrap;margin:28px 0}.stat{border:1px solid var(--line);padding:12px 18px;background:var(--surface);border-radius:12px}.stat strong{font-size:1.5rem;color:var(--accent);display:block;line-height:1.2}.stat small{color:var(--muted)}.section-head{display:flex;align-items:end;justify-content:space-between;gap:18px;flex-wrap:wrap;margin:24px 0}.grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px}.challenge-card{display:flex;flex-direction:column;min-height:248px;border:1px solid var(--line);background:linear-gradient(155deg,var(--surface),#101d2e);padding:22px;border-radius:var(--radius);transition:transform .16s,border-color .16s}.challenge-card:hover{transform:translateY(-3px);border-color:#78b6de}.challenge-card p{color:var(--muted);font-size:.91rem;flex:1}.card-top{display:flex;justify-content:space-between;align-items:center;gap:8px;margin-bottom:15px}.number{font-size:.9rem;font-weight:850;color:var(--accent)}.card-status{font-size:.82rem;color:#c7d9ee}.card-tag{font-size:.78rem;color:var(--accent2);margin-bottom:8px}.button{display:inline-block;text-decoration:none;border:1px solid #74eec0;background:var(--accent);color:#09271f;border-radius:10px;padding:10px 16px;font-weight:800;text-align:center}.button:hover{color:#09271f;background:#a2ffdb}.button.secondary{background:transparent;color:var(--text);border-color:#536d88}.button.secondary:hover{color:var(--accent);border-color:var(--accent)}.challenge-card .button{align-self:flex-start}.panel{padding:26px;border:1px solid var(--line);border-radius:var(--radius);background:var(--surface);margin:22px 0}.panel.soft{background:#101d2d}.panel p:last-child{margin-bottom:0}.two-col{display:grid;grid-template-columns:1.4fr 1fr;gap:20px}.field{display:flex;flex-direction:column;gap:6px;max-width:520px;margin:12px 0}.field label{font-weight:700}.field input{width:100%;background:#09182a;border:1px solid #53708a;border-radius:9px;padding:11px 12px;color:var(--text)}.field input:focus{outline:2px solid var(--accent);outline-offset:2px}.actions{display:flex;gap:12px;flex-wrap:wrap;align-items:center;margin:17px 0}.notice{padding:13px 15px;border-left:3px solid var(--accent2);background:#1a304c;border-radius:5px;color:#dceaff;margin:14px 0}.feedback{min-height:25px;color:var(--accent);font-weight:700;overflow-wrap:anywhere}.hint{border:1px solid #4a657e;border-radius:12px;padding:10px 15px;margin:18px 0;background:#102039}.hint summary{cursor:pointer;font-weight:750}.hint p{margin-top:12px;color:var(--muted)}.flag{font-family:ui-monospace,SFMono-Regular,Consolas,monospace;padding:6px 9px;background:#091c22;color:#a5ffdc;border:1px dashed #69c9a3;border-radius:7px;overflow-wrap:anywhere}.muted{color:var(--muted)}.footer{margin-top:75px;padding:22px 0;border-top:1px solid var(--line);color:var(--muted);font-size:.88rem}.challenge-header{padding:56px 0 10px}.challenge-header h1{font-size:clamp(2rem,5vw,3.25rem)}.breadcrumb{color:var(--muted);font-size:.88rem}.breadcrumb a{color:var(--muted)}.progressbar{height:12px;background:#1e334b;border-radius:30px;overflow:hidden}.progressbar div{height:100%;background:linear-gradient(90deg,#70efc0,#80aeff);width:0;transition:width .3s}.toolbox{display:flex;gap:12px;flex-wrap:wrap}.code{white-space:pre-wrap;word-break:break-word;font-family:ui-monospace,Consolas,monospace;background:#081425;border:1px solid #38506a;border-radius:11px;padding:16px}.tiny{font-size:.85rem}.fake-white{background:white;color:white;border-radius:8px;padding:26px;margin:16px 0;min-height:72px}.secret-button[hidden]{display:none}.footnote{margin:40px 0;color:var(--muted);font-size:.9rem}@media(max-width:860px){.grid{grid-template-columns:repeat(2,minmax(0,1fr))}.two-col{grid-template-columns:1fr}}@media(max-width:580px){.grid{grid-template-columns:1fr}.hero{padding-top:48px}.nav{align-items:flex-start;padding:12px 0;flex-direction:column;gap:6px}.panel{padding:18px}.stats{gap:8px}.stat{flex:1;min-width:110px}}

/* Navigation, états et schéma pédagogique. */
:root{--error:#ff9ca8;--pending:#ffd18a}html{scroll-padding-top:100px}.brand{display:inline-flex;align-items:center;gap:5px}.brand-icon{width:26px;height:26px;color:var(--accent);flex-shrink:0}.feedback.is-error{color:var(--error)}.feedback.is-success{color:var(--accent)}.card-status{color:var(--pending);background:#ffd18a12;border:1px solid #ffd18a66;padding:4px 9px;border-radius:20px;font-weight:800;white-space:nowrap}.card-status.is-done{color:var(--accent);background:#70efc018;border-color:#70efc080}.rules{padding-left:20px;margin:0 0 14px}.rules li+li{margin-top:5px}.client-server{display:flex;align-items:center;gap:18px;margin:24px 0}.network-node{flex:1;display:flex;flex-direction:column;padding:18px;border:1px solid var(--line);border-radius:12px;background:var(--bg)}.network-node strong{color:var(--accent)}.network-node small{color:var(--muted)}.network-exchange{display:flex;flex-direction:column;gap:12px;color:var(--accent2);font-size:.85rem;text-align:center}@media(max-width:580px){html{scroll-padding-top:130px}.client-server{flex-direction:column;align-items:stretch}.card-top{flex-wrap:wrap}}

.morse-table{display:grid;grid-template-columns:repeat(auto-fit,minmax(110px,1fr));gap:8px;margin-top:15px}.morse-table span{padding:5px;background:var(--bg);border-radius:5px}.code{max-width:100%;overflow-wrap:anywhere}.field input[type=number]{max-width:220px}