:root{--nav:#172554;--blue:#2563eb;--violet:#7c3aed;--paper:#f5f7fb;--ink:#172033;--ok:#15803d;--warn:#d97706;--bad:#c2410c}*{box-sizing:border-box}html,body,#app{min-height:100%;margin:0}body{font:17px/1.55 system-ui,sans-serif;background:var(--paper);color:var(--ink)}button{font:inherit;cursor:pointer}header{height:74px;background:var(--nav);color:white;display:flex;align-items:center;gap:14px;padding:10px 18px;position:sticky;top:0;z-index:5}header div{flex:1}header strong,header small{display:block}header small{opacity:.8}header button{border:0;border-radius:10px;padding:.55rem .8rem}#menu{display:none}.progress{height:7px;background:#dbe4f0;position:sticky;top:74px;z-index:5}.progress span{display:block;height:100%;background:linear-gradient(90deg,var(--blue),var(--violet));transition:width .3s}.layout{display:grid;grid-template-columns:260px 1fr;min-height:calc(100vh - 143px)}nav{background:#e8eef8;padding:16px;overflow:auto}nav button{display:block;width:100%;text-align:left;border:0;background:transparent;padding:10px;border-radius:9px;margin:2px 0}nav button.active{background:white;color:var(--blue);font-weight:700}nav button.done:after{content:' ✓';color:var(--ok)}main{max-width:960px;width:100%;padding:34px 5vw 110px}h1{font-size:clamp(1.8rem,4vw,3rem);line-height:1.1}h2{margin-top:2rem}.lead{font-size:1.2rem}.card,.chat,.task,.memory{background:white;border-radius:16px;padding:20px;margin:18px 0;box-shadow:0 6px 24px #20305012}.memory{border-left:7px solid var(--violet)}.chat{max-width:650px}.bubble{padding:12px 16px;background:#eaf1ff;border-radius:15px 15px 15px 3px;margin:10px 0;max-width:80%}.bubble.right{margin-left:auto;background:#fff1d6;border-radius:15px 15px 3px 15px}.choices{display:grid;gap:10px;margin-top:14px}.choices button{text-align:left;border:2px solid #d9e1ed;background:white;padding:12px;border-radius:10px}.choices button:hover,.choices button:focus{border-color:var(--blue)}.choices button.correct{border-color:var(--ok);background:#eaf8ee}.choices button.wrong{border-color:#dc2626;background:#fff0f0}.feedback{min-height:1.5em;font-weight:700;margin-top:10px}.roles{display:grid;grid-template-columns:repeat(auto-fit,minmax(180px,1fr));gap:12px}.tag{padding:4px 9px;border-radius:99px;background:#e7edff}footer{position:fixed;bottom:0;left:260px;right:0;display:flex;align-items:center;justify-content:space-between;background:white;border-top:1px solid #dce3ee;padding:12px 5vw;z-index:4}footer button{border:0;border-radius:10px;padding:10px 18px;background:var(--blue);color:white}dialog{max-width:600px;border:0;border-radius:18px;padding:28px;box-shadow:0 20px 70px #0005}.close{float:right;border:0;background:transparent;font-size:2rem}@media(max-width:760px){header{height:auto;min-height:70px}header small{display:none}#help{font-size:.8rem}#menu{display:block}nav{position:fixed;top:77px;bottom:0;left:-280px;width:260px;z-index:8;box-shadow:4px 0 20px #0003;transition:left .2s}.nav-open nav{left:0}.layout{grid-template-columns:1fr}main{padding:24px 18px 100px}footer{left:0;padding:10px 18px}.progress{top:70px}}@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;transition:none!important}}