:root{--bg:#090c10;--bg-2:#10141a;--fg:#e6edf3;--muted:#8b949e;--primary:#0cb0a3;--primary-2:#2ec0b4;--card:rgba(16,20,26,.95);--border:#21262d;--glow:rgba(13,212,196,.3);--shadow:0 10px 40px rgba(0,0,0,.5)}:root[data-theme=light]{--bg:#fff;--bg-2:#f8f9fa;--fg:#0f172a;--muted:#475569;--primary:#059c8e;--primary-2:#0ab4a4;--card:#fff;--border:#cbd5e1;--glow:rgba(5,156,142,.4);--shadow:0 8px 28px rgba(0,0,0,.15)}*{box-sizing:border-box}body{margin:0;font-family:Inter,system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif;color:var(--fg);background:radial-gradient(120% 120% at 20% 20%,rgba(13,212,196,.07),transparent),radial-gradient(120% 120% at 80% 0,rgba(61,232,218,.04),transparent),linear-gradient(135deg,var(--bg),var(--bg-2));min-height:100vh;position:relative;overflow-x:hidden}body:before{content:"";position:fixed;top:50%;left:50%;transform:translate(-50%,-50%);width:600px;height:600px;background-image:url(/logo.png);background-size:contain;background-repeat:no-repeat;background-position:50%;opacity:.15;pointer-events:none;z-index:0}:root[data-theme=light] body{background:radial-gradient(120% 120% at 20% 20%,rgba(5,156,142,.12),transparent),radial-gradient(120% 120% at 80% 0,rgba(10,180,164,.08),transparent),linear-gradient(135deg,#fff,#f1f5f9)}a{color:inherit;text-decoration:none}.app-shell{position:relative;z-index:10;min-height:100vh;padding:0;display:flex;flex-direction:column}@media (max-width:768px){.app-shell{padding:0}}.nav{position:static;z-index:1000;display:flex;align-items:center;justify-content:space-between;padding:16px 40px;backdrop-filter:none;-webkit-backdrop-filter:none;width:100%}.nav,:root[data-theme=light] .nav{background:transparent;border-bottom:none;box-shadow:none}.nav-logo{display:inline-flex;align-items:center;gap:12px;font-weight:800;font-size:22px;letter-spacing:.3px;color:var(--fg);padding:4px 8px;border-radius:12px;transition:all .2s ease}.nav-logo:hover{background:rgba(13,212,196,.05)}.nav-logo img{width:44px;height:44px;object-fit:contain;filter:drop-shadow(0 2px 8px rgba(13,212,196,.3))}:root[data-theme=light] .nav-logo img{filter:drop-shadow(0 2px 8px rgba(5,156,142,.2))}.nav-left{display:inline-flex;align-items:center;gap:10px}.nav-links{display:flex;gap:12px}.mobile-menu-checkbox,.mobile-menu-overlay{display:none}.menu-toggle{display:none;align-items:center;justify-content:center;width:40px;height:40px;border-radius:10px;border:1px solid hsla(0,0%,100%,.12);background:hsla(0,0%,100%,.06);color:var(--fg);cursor:pointer;transition:transform .1s ease,opacity .1s ease;touch-action:manipulation;-webkit-tap-highlight-color:transparent}.menu-toggle:active{transform:scale(.9);opacity:.6}.nav-center{flex:1 1;justify-content:center}.nav-actions,.nav-center{display:flex;gap:8px;align-items:center}.nav a{padding:10px 18px;border-radius:12px;border:1px solid transparent;color:rgba(226,232,240,.7);font-weight:600;font-size:15px;transition:all .2s ease;text-decoration:none;display:inline-flex;align-items:center;justify-content:center;white-space:nowrap}.nav a:hover{color:#fff;border-color:rgba(13,212,196,.3);background:rgba(13,212,196,.12);transform:translateY(-1px)}.nav a.active{color:#fff;border-color:rgba(13,212,196,.5);background:linear-gradient(135deg,rgba(13,212,196,.2),rgba(10,180,164,.25));box-shadow:0 4px 12px rgba(13,212,196,.25),inset 0 1px 0 hsla(0,0%,100%,.1);font-weight:700}:root[data-theme=light] .nav a{color:rgba(71,85,105,.8)}:root[data-theme=light] .nav a:hover{color:#0f172a;border-color:rgba(5,156,142,.3);background:rgba(5,156,142,.1)}:root[data-theme=light] .nav a.active{color:#047a6e;border-color:rgba(5,156,142,.5);background:linear-gradient(135deg,rgba(5,156,142,.15),rgba(10,180,164,.2));box-shadow:0 4px 12px rgba(5,156,142,.2),inset 0 1px 0 hsla(0,0%,100%,.5)}.theme-toggle{background:rgba(13,212,196,.1);border:1px solid rgba(13,212,196,.2);font-size:20px;cursor:pointer;padding:8px 10px;border-radius:10px;transition:all .2s ease;display:flex;align-items:center;justify-content:center;min-width:42px;min-height:42px}.theme-toggle:hover{background:rgba(13,212,196,.18);border-color:rgba(13,212,196,.4);transform:translateY(-2px) scale(1.05);box-shadow:0 4px 12px rgba(13,212,196,.3)}.theme-toggle:active{transform:translateY(0) scale(.98)}:root[data-theme=light] .theme-toggle{background:rgba(5,156,142,.08);border-color:rgba(5,156,142,.2)}:root[data-theme=light] .theme-toggle:hover{background:rgba(5,156,142,.15);border-color:rgba(5,156,142,.4);box-shadow:0 4px 12px rgba(5,156,142,.2)}.promo-banner{animation:fadeInUp .6s ease-out}@keyframes fadeInUp{0%{opacity:0;transform:translateY(20px)}to{opacity:1;transform:translateY(0)}}@keyframes pulse{0%,to{transform:scale(1)}50%{transform:scale(1.05)}}.promo-cta{position:relative;z-index:1;display:inline-flex;align-items:center;gap:10px;font-size:20px;font-weight:800;padding:18px 40px;background:#fff;color:#059c8e;border-radius:16px;box-shadow:0 8px 24px rgba(0,0,0,.25),0 0 0 4px hsla(0,0%,100%,.3);transition:all .3s ease;cursor:pointer;text-decoration:none;border:none}.promo-cta:hover{transform:translateY(-4px) scale(1.05);box-shadow:0 12px 32px rgba(0,0,0,.3),0 0 0 6px hsla(0,0%,100%,.4)}.promo-cta:active{transform:translateY(-2px) scale(1.02)!important}.page{position:relative;z-index:10;display:flex;flex-direction:column;gap:24px}@media (max-width:768px){.page{padding:20px 20px 0}}.section{background:var(--card);border:1px solid var(--border);border-radius:18px;padding:24px;box-shadow:var(--shadow)}.stack{display:flex;flex-direction:column;gap:12px}.grid{display:grid;grid-gap:16px;gap:16px}.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:12px 16px;border-radius:12px;border:1px solid transparent;font-weight:700;cursor:pointer;transition:all .15s ease;color:#0b1021;background:linear-gradient(135deg,var(--primary),var(--primary-2));box-shadow:0 10px 30px rgba(77,215,255,.25)}.btn:hover{transform:translateY(-1px);box-shadow:0 12px 32px rgba(77,215,255,.35)}.btn.secondary{background:transparent;color:var(--fg);border-color:var(--border);box-shadow:none}:root[data-theme=light] .btn{color:#fff;background:linear-gradient(135deg,#059c8e,#0ab4a4);box-shadow:0 8px 24px rgba(5,156,142,.35)}:root[data-theme=light] .btn:hover{box-shadow:0 10px 28px rgba(5,156,142,.45)}:root[data-theme=light] .btn.secondary{background:transparent;color:var(--fg);border-color:var(--border)}.pill{display:inline-flex;padding:12px 24px;border-radius:999px;background:linear-gradient(135deg,rgba(77,215,255,.15),rgba(77,215,255,.08));color:var(--primary);border:1.5px solid rgba(77,215,255,.4);font-weight:800;font-size:18px;letter-spacing:.3px;box-shadow:0 4px 12px rgba(77,215,255,.15);-webkit-backdrop-filter:blur(8px);backdrop-filter:blur(8px)}:root[data-theme=light] .pill{background:linear-gradient(135deg,rgba(5,156,142,.12),rgba(5,156,142,.06));color:#059c8e;border-color:rgba(5,156,142,.35);box-shadow:0 4px 12px rgba(5,156,142,.12)}.card{border:1px solid var(--border);border-radius:16px;padding:16px;background:rgba(12,22,43,.9);box-shadow:var(--shadow)}:root[data-theme=light] .card,:root[data-theme=light] .section{background:#fff;border-color:#cbd5e1;box-shadow:0 4px 16px rgba(0,0,0,.08)}:root[data-theme=light] h1,:root[data-theme=light] h2,:root[data-theme=light] h3{color:#0f172a;font-weight:800}:root[data-theme=light] .nav-logo{color:#0f172a}:root[data-theme=light] .promo-banner{background:linear-gradient(135deg,#0ab4a4,#059c8e,#047a6e)!important}:root[data-theme=light] .promo-cta{background:#fff!important;color:#047a6e!important;box-shadow:0 8px 24px rgba(4,122,110,.3),0 0 0 4px hsla(0,0%,100%,.4)!important}:root[data-theme=light] .promo-cta:hover{box-shadow:0 12px 32px rgba(4,122,110,.4),0 0 0 6px hsla(0,0%,100%,.5)!important}.auth-link{color:var(--primary);font-weight:600;text-decoration:none;border-bottom:2px solid transparent;transition:all .2s ease;padding-bottom:2px}.auth-link:hover{border-bottom-color:var(--primary);color:var(--primary-2)}.hero-title{margin:0;font-size:clamp(28px,4vw,40px)}.hero-sub{margin:0;max-width:680px}.hero-sub,.muted{color:var(--muted)}.glass{border:1px solid var(--border);background:rgba(12,22,43,.82);border-radius:16px;padding:16px;-webkit-backdrop-filter:blur(8px);backdrop-filter:blur(8px)}.plan-card{position:relative;overflow:hidden;transition:all .3s ease}.plan-card:after{content:"";position:absolute;inset:0;pointer-events:none;background:radial-gradient(circle at 80% 20%,rgba(77,215,255,.15),transparent 45%)}.plan-card:hover{transform:translateY(-8px);box-shadow:0 16px 48px rgba(13,212,196,.25)}.popular-plan{box-shadow:0 12px 40px rgba(13,212,196,.35),0 0 0 2px var(--primary)}.popular-plan:hover{box-shadow:0 20px 60px rgba(13,212,196,.4),0 0 0 2px var(--primary)}:root[data-theme=light] .popular-plan{box-shadow:0 12px 40px rgba(5,156,142,.3),0 0 0 2px #059c8e}:root[data-theme=light] .popular-plan:hover{box-shadow:0 20px 60px rgba(5,156,142,.35),0 0 0 2px #059c8e}@media (max-width:768px){.nav{position:static!important;padding:14px 18px;gap:0;border-radius:0!important;margin:0 0 20px!important;z-index:1400!important;width:100%}.nav-left{display:flex;align-items:center;gap:12px;position:relative;z-index:1500}.nav-logo{font-size:18px;gap:6px}.nav-logo img{width:34px;height:34px}.menu-toggle{display:inline-flex!important;position:relative;z-index:1500}.mobile-menu-overlay{display:none;position:fixed;inset:0;background:rgba(0,0,0,.6);-webkit-backdrop-filter:blur(4px);backdrop-filter:blur(4px);z-index:1300}.mobile-menu-checkbox:checked~.mobile-menu-overlay{display:block}.nav-center{position:fixed;top:62px;right:0;height:calc(100vh - 62px);width:75vw;max-width:280px;display:flex;flex-direction:column;justify-content:flex-start;align-items:stretch;gap:4px;padding:20px 16px;background:rgba(13,27,42,.98);-webkit-backdrop-filter:blur(20px);backdrop-filter:blur(20px);border-left:1px solid rgba(13,212,196,.2);box-shadow:none;z-index:1500;transform:translateX(100%);opacity:0;pointer-events:none;transition:transform .28s cubic-bezier(.4,0,.2,1),opacity .28s ease;overflow-y:auto}.mobile-menu-checkbox:checked~.mobile-menu-overlay{display:block!important}.nav:has(.mobile-menu-checkbox:checked) .nav-center{transform:translateX(0);opacity:1;pointer-events:auto;box-shadow:-16px 0 40px rgba(0,0,0,.5)}.nav-links a{width:100%;padding:14px 16px;font-size:15px;justify-content:flex-start;border-radius:10px}.nav-actions{-webkit-margin-start:auto;margin-inline-start:auto;flex-shrink:0;gap:6px}.nav-actions a{padding:8px 14px;font-size:13px;white-space:nowrap}.theme-toggle{display:none!important}.grid{gap:32px!important}.section{border-radius:12px;padding:24px 16px!important}.grid{grid-template-columns:1fr!important}.page{padding:20px 16px 0!important}.lesson-content{padding:0!important;background:transparent!important;border:none!important;box-shadow:none!important;font-size:16px!important;margin-top:16px!important;border-radius:0!important}.lesson-content h2,.lesson-content h3,.lesson-content li,.lesson-content p{word-break:break-word;overflow-wrap:break-word}.premium-card-container{width:100%!important;max-width:100%!important;aspect-ratio:1/1.15!important;height:auto!important;max-height:65vh!important}.card-scroll-area{padding:60px 16px 20px!important}.premium-answer,.premium-question{font-size:18px!important}.eval-actions{flex-direction:column!important;gap:12px!important;align-items:stretch!important;margin-top:20px!important}.eval-btn{padding:14px 16px!important;font-size:15px!important;justify-content:center!important;border-radius:14px!important}.eval-btn .icon{font-size:18px!important}}.social-icon{display:inline-flex;align-items:center;justify-content:center;font-size:28px;color:var(--fg);opacity:.8;transition:all .2s ease;text-decoration:none}.social-icon:hover{opacity:1;transform:scale(1.15);color:var(--primary)}:root[data-theme=light] .social-icon:hover{color:#059c8e}footer a{transition:all .2s ease}footer a:hover{color:var(--primary)!important;text-decoration:underline!important}.footer-legal-link{font-size:13px;color:var(--muted);text-decoration:none;transition:color .2s ease}.footer-legal-link:hover{color:var(--primary)!important}:root[data-theme=light] footer a:hover{color:#059c8e!important}.store-badge{display:inline-flex;border-radius:12px;overflow:hidden;background:#000;border:1px solid hsla(0,0%,100%,.12);box-shadow:0 4px 12px rgba(0,0,0,.25);transition:transform .2s ease,box-shadow .2s ease}.store-badge:hover{transform:scale(1.05);box-shadow:0 6px 16px rgba(0,0,0,.35)}.premium-card-container{perspective:1500px;width:100%;max-width:900px;aspect-ratio:2/1;min-height:350px;margin:0 auto;position:relative}.card-glow-backdrop{position:absolute;inset:-10%;background:radial-gradient(circle at 50% 50%,rgba(13,212,196,.15) 0,transparent 60%);filter:blur(40px);z-index:-1;pointer-events:none}.flashcard{width:100%;height:100%;cursor:pointer}.flashcard-inner{position:relative;width:100%;height:100%;text-align:center;transition:transform .7s cubic-bezier(.175,.885,.32,1.275);transform-style:preserve-3d}.flashcard.flipped .flashcard-inner{transform:rotateY(180deg)}.premium-face{-webkit-backface-visibility:hidden;backface-visibility:hidden;border-radius:32px;background:linear-gradient(145deg,rgba(22,28,45,.95),rgba(13,17,28,.98));border:1px solid hsla(0,0%,100%,.05);box-shadow:0 30px 60px -12px rgba(0,0,0,.6),inset 0 1px 0 hsla(0,0%,100%,.08);transition:all .4s cubic-bezier(.175,.885,.32,1.275);overflow:hidden}.card-scroll-area,.premium-face{position:absolute;width:100%;height:100%}.card-scroll-area{inset:0;padding:80px 40px 40px;display:flex;flex-direction:column;justify-content:flex-start;align-items:center;overflow-y:auto}.card-scroll-area::-webkit-scrollbar{width:6px}.card-scroll-area::-webkit-scrollbar-track{background:transparent}.card-scroll-area::-webkit-scrollbar-thumb{background:rgba(13,212,196,.2);border-radius:10px}.card-scroll-area::-webkit-scrollbar-thumb:hover{background:rgba(13,212,196,.4)}.premium-face:hover{border-color:rgba(13,212,196,.3);box-shadow:0 40px 80px -10px rgba(13,212,196,.15),inset 0 1px 0 hsla(0,0%,100%,.1)}.premium-back{transform:rotateY(180deg);background:linear-gradient(145deg,rgba(13,17,28,.98),rgba(22,28,45,.95));border-color:rgba(13,212,196,.2)}.card-tag{position:absolute;top:24px;left:24px;z-index:10;font-size:13px;font-weight:700;letter-spacing:1.5px;padding:8px 20px;border-radius:99px;background:rgba(13,212,196,.1);color:var(--primary);border:1px solid rgba(13,212,196,.2);text-transform:uppercase;-webkit-backdrop-filter:blur(4px);backdrop-filter:blur(4px)}.premium-question{font-weight:500;line-height:1.6;color:hsla(0,0%,100%,.9)}.premium-answer,.premium-question{font-size:clamp(20px,2.5vw,26px);margin:auto 0;width:100%}.premium-answer{font-weight:600;line-height:1.7;color:var(--primary)}.click-hint{margin-top:32px;font-size:14px;color:var(--muted);font-weight:500;display:flex;align-items:center;gap:8px;opacity:.6;animation:pulse-slow 2s infinite}@keyframes pulse-slow{0%{opacity:.4}50%{opacity:.8}to{opacity:.4}}.eval-actions{display:flex;gap:24px;justify-content:center;margin-top:40px;opacity:0;pointer-events:none;transform:translateY(20px);transition:all .4s cubic-bezier(.4,0,.2,1)}.eval-actions.visible{opacity:1;pointer-events:auto;transform:translateY(0)}.eval-btn{display:flex;align-items:center;gap:12px;padding:16px 32px;border-radius:16px;font-size:18px;font-weight:700;cursor:pointer;border:1px solid transparent;transition:all .2s cubic-bezier(.175,.885,.32,1.275);box-shadow:0 10px 20px -5px rgba(0,0,0,.3)}.eval-btn .icon{font-size:24px}.eval-wrong{background:rgba(239,68,68,.1);color:#fca5a5;border-color:rgba(239,68,68,.3)}.eval-wrong:hover{background:rgba(239,68,68,.2);transform:translateY(-4px) scale(1.02);box-shadow:0 15px 30px -5px rgba(239,68,68,.25)}.eval-correct{background:rgba(34,197,94,.1);color:#86efac;border-color:rgba(34,197,94,.3)}.eval-correct:hover{background:rgba(34,197,94,.2);transform:translateY(-4px) scale(1.02);box-shadow:0 15px 30px -5px rgba(34,197,94,.25)}@keyframes bounce{0%,20%,50%,80%,to{transform:translateY(0)}40%{transform:translateY(-20px)}60%{transform:translateY(-10px)}}.glass-card{position:relative;background:rgba(12,22,43,.6);border:1px solid rgba(13,212,196,.15);border-radius:20px;padding:24px;-webkit-backdrop-filter:blur(12px);backdrop-filter:blur(12px);overflow:hidden;transition:all .3s cubic-bezier(.4,0,.2,1);display:flex;flex-direction:column;gap:16px;cursor:pointer;text-decoration:none;box-shadow:0 8px 32px rgba(0,0,0,.2)}.glass-card:before{content:"";position:absolute;inset:0;background:linear-gradient(135deg,hsla(0,0%,100%,.05),transparent);opacity:0;transition:opacity .3s ease}.glass-card:hover{transform:translateY(-6px) scale(1.02);border-color:rgba(13,212,196,.4);box-shadow:0 16px 48px rgba(13,212,196,.2)}.glass-card:hover:before{opacity:1}:root[data-theme=light] .glass-card{background:hsla(0,0%,100%,.8);border-color:rgba(5,156,142,.2);box-shadow:0 8px 24px rgba(0,0,0,.05)}:root[data-theme=light] .glass-card:hover{border-color:rgba(5,156,142,.5);box-shadow:0 16px 40px rgba(5,156,142,.15)}.lesson-timeline{display:flex;flex-direction:column;gap:24px;position:relative;max-width:800px;margin:0 auto}.lesson-item{display:flex;background:rgba(22,27,34,.8);border-radius:16px;padding:20px;border:1px solid hsla(0,0%,100%,.05);box-shadow:0 8px 24px rgba(0,0,0,.15);transition:all .2s ease;cursor:pointer;align-items:center;gap:20px;text-decoration:none}.lesson-item:hover{transform:translateX(-4px);border-color:rgba(13,212,196,.3);box-shadow:0 12px 32px rgba(13,212,196,.1)}.lesson-item.high-yield{border:1px solid rgba(234,179,8,.3);background:linear-gradient(90deg,rgba(234,179,8,.05),rgba(22,27,34,.8))}.lesson-item.high-yield:hover{border-color:rgba(234,179,8,.6);box-shadow:0 12px 32px rgba(234,179,8,.15)}:root[data-theme=light] .lesson-item{background:#fff;border-color:#e2e8f0}:root[data-theme=light] .lesson-item.high-yield{background:linear-gradient(90deg,rgba(234,179,8,.1),#fff);border-color:rgba(234,179,8,.4)}.lesson-badge{padding:6px 12px;border-radius:8px;font-size:13px;font-weight:700;letter-spacing:.5px;text-transform:uppercase}.badge-comparison{background:rgba(139,92,246,.15);color:#a78bfa;border:1px solid rgba(139,92,246,.3)}.badge-key_points{background:rgba(16,185,129,.15);color:#34d399;border:1px solid rgba(16,185,129,.3)}.badge-definition{background:rgba(56,189,248,.15);color:#7dd3fc;border:1px solid rgba(56,189,248,.3)}.lesson-content{background:var(--card);border:1px solid var(--border);border-radius:24px;padding:40px;margin-top:32px;box-shadow:var(--shadow);line-height:1.8;font-size:18px}.lesson-content h2{color:var(--primary);margin-bottom:20px;font-size:28px}.lesson-content hr{border:0;height:1px;background:var(--border);margin:32px 0}.tag-Diagnosis{color:#f472b6;border-color:rgba(244,114,182,.3);background:rgba(244,114,182,.1)}.tag-Management{color:#60a5fa;border-color:rgba(96,165,250,.3);background:rgba(96,165,250,.1)}.tag-Red-Flag{color:#ef4444;border-color:rgba(239,68,68,.3);background:rgba(239,68,68,.1)}.book-icon-card{flex-direction:column;justify-content:flex-start;gap:12px;width:140px;text-align:center;text-decoration:none;cursor:pointer;transition:transform .2s ease}.book-icon-card,.icon-wrapper{display:flex;align-items:center}.icon-wrapper{width:90px;height:90px;background:rgba(12,22,43,.6);border:1px solid rgba(13,212,196,.2);border-radius:20px;justify-content:center;font-size:44px;box-shadow:0 8px 24px rgba(0,0,0,.15);transition:all .3s cubic-bezier(.4,0,.2,1);-webkit-backdrop-filter:blur(12px);backdrop-filter:blur(12px)}.book-icon-card:hover .icon-wrapper{background:rgba(13,212,196,.1);border-color:rgba(13,212,196,.4);transform:translateY(-8px) scale(1.05);box-shadow:0 16px 32px rgba(13,212,196,.25)}.icon-title{font-size:15px;font-weight:700;color:var(--fg);line-height:1.4}.icon-subtitle{font-size:12px;color:var(--muted)}.tag-Number{color:#a78bfa;border-color:rgba(167,139,250,.3);background:rgba(167,139,250,.1)}.tag-First-Line{color:#34d399;border-color:rgba(52,211,153,.3);background:rgba(52,211,153,.1)}