:root{font-family:Inter,ui-sans-serif,system-ui,sans-serif;color:#e2e8f0;background:#07111f;font-synthesis:none}*{box-sizing:border-box}body{margin:0;min-width:320px}.app-shell{max-width:1240px;margin:0 auto;padding:28px 22px 64px}.hero{padding:38px 0 34px;max-width:720px}.eyebrow,.section-label{color:#67e8f9;font-size:.72rem;font-weight:800;letter-spacing:.16em;text-transform:uppercase}.hero h1{font-size:clamp(3.4rem,8vw,6.5rem);line-height:.9;margin:14px 0;background:linear-gradient(110deg,#fff,#67e8f9);-webkit-background-clip:text;color:transparent}.hero-copy{font-size:1.1rem;color:#94a3b8;line-height:1.6}.workspace{display:grid;grid-template-columns:280px 1fr;gap:22px}.module-panel,.content-panel,.lesson-panel{border:1px solid #1e334d;background:#0b192b;border-radius:24px;padding:20px}.module-panel{align-self:start}.module-card,.topic-card{display:flex;width:100%;text-align:left;border:1px solid #233b57;background:#102239;color:#e2e8f0;border-radius:16px;padding:16px;margin-top:12px;cursor:pointer;transition:.2s}.module-card{flex-direction:column;gap:7px}.module-card:hover,.module-card.active,.topic-card:hover{border-color:#67e8f9;transform:translateY(-2px)}.module-card span,.topic-card span,.lesson-card span{font-size:.75rem;color:#67e8f9}.module-card strong,.topic-card strong{font-size:1rem}.panel-heading{display:flex;justify-content:space-between;gap:16px;align-items:start}.panel-heading h2{font-size:clamp(1.5rem,3vw,2.4rem);margin:7px 0}.level-pill,.activity-count{border:1px solid #28506d;border-radius:999px;padding:8px 12px;color:#a5f3fc;font-size:.8rem;white-space:nowrap}.topic-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(210px,1fr));gap:12px;margin-top:24px}.topic-card{flex-direction:column;gap:10px;min-height:130px}.topic-card small,.lesson-card small{color:#94a3b8}.error-box{background:#451a1a;border:1px solid #ef4444;color:#fecaca;border-radius:12px;padding:12px;margin-top:20px}.lesson-panel{margin-top:22px;background:#0e2034}.compact{align-items:center}.lesson-list{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:12px}.lesson-card{background:#122842;border:1px solid #254562;border-radius:16px;padding:16px}.lesson-card h3{margin:8px 0;font-size:1rem}.lesson-card p{color:#a8b8ca;line-height:1.5;font-size:.9rem}@media(max-width:760px){.app-shell{padding:18px 14px 40px}.workspace{grid-template-columns:1fr}.module-panel{display:flex;gap:8px;overflow:auto}.module-panel .section-label{display:none}.module-card{min-width:210px;margin:0}.panel-heading{flex-direction:column}.level-pill,.activity-count{align-self:flex-start}}.auth-shell{min-height:100vh;display:grid;place-items:center;padding:24px}.auth-card{width:min(100%,460px);padding:32px;border:1px solid #1e334d;background:#0b192b;border-radius:24px;box-shadow:0 20px 70px #020617}.auth-card h1{font-size:3.5rem;margin:10px 0;background:linear-gradient(110deg,#fff,#67e8f9);-webkit-background-clip:text;color:transparent}.auth-card h2{margin-top:28px}.auth-card form{display:grid;gap:16px}.auth-card label{display:grid;gap:7px;color:#cbd5e1;font-size:.9rem}.auth-card input{border:1px solid #29445e;background:#102239;color:#fff;border-radius:10px;padding:12px;font-size:1rem}.primary-button,.link-button,.signout-button{border:0;border-radius:10px;padding:12px 16px;cursor:pointer;font-weight:700}.primary-button{background:#67e8f9;color:#06202b}.link-button{background:transparent;color:#67e8f9;margin-top:18px;padding-left:0}.auth-message{color:#fcd34d;line-height:1.4}.signout-button{background:#102239;color:#a5f3fc;float:right}.lesson-player{margin-top:22px;border:1px solid #2d7180;background:#0b2636;border-radius:22px;padding:22px}.lesson-objective{color:#b6c8d8;line-height:1.5}.exercise-card{margin-top:18px;padding:22px;border-radius:18px;background:#102f44}.exercise-card h3{font-size:1.35rem;line-height:1.35}.option-list{display:grid;gap:10px;margin-top:20px}.option-button{border:1px solid #3a6477;background:#153d55;color:#e2e8f0;border-radius:12px;padding:14px;text-align:left;cursor:pointer;font-size:1rem}.option-button:hover{border-color:#67e8f9;background:#1c5269}.feedback{display:grid;gap:18px;margin-top:18px;padding:18px;border-radius:14px}.feedback.success{background:#123c35;color:#a7f3d0;border:1px solid #34d399}.feedback.error{background:#451a1a;color:#fecaca;border:1px solid #ef4444}.lesson-button{margin-top:14px;padding:9px 12px;font-size:.85rem}.open-answer{display:grid;gap:12px;margin-top:20px}.open-answer textarea{width:100%;resize:vertical;border:1px solid #3a6477;background:#0a2032;color:#fff;border-radius:12px;padding:14px;font:inherit;line-height:1.5}.open-answer textarea:focus{outline:2px solid #67e8f9}