@import "https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap";*{box-sizing:border-box;margin:0;padding:0}body{color:#334155;-webkit-font-smoothing:antialiased;background-color:#f8fafc;font-family:Inter,sans-serif;line-height:1.8}.app-container{flex-direction:column;min-height:100vh;display:flex}.header{color:#fff;background-color:#0f172a;justify-content:space-between;align-items:center;padding:1.2rem 2rem;display:flex;box-shadow:0 2px 10px #0000001a}.logo{color:#38bdf8;cursor:pointer;letter-spacing:-.5px;font-size:1.5rem;font-weight:700}.top-nav{gap:1.5rem;display:flex}.top-nav button{color:#cbd5e1;cursor:pointer;background:0 0;border:none;border-radius:6px;padding:.5rem .8rem;font-family:inherit;font-size:.95rem;font-weight:600;transition:all .3s}.top-nav button:hover,.top-nav button.active-nav{color:#38bdf8;background-color:#ffffff0d}.main-layout{flex:1;gap:2.5rem;width:100%;max-width:1250px;margin:0 auto;padding:2.5rem 1.5rem;display:flex}.sidebar{background:#fff;border-radius:12px;flex-direction:column;flex:0 0 320px;align-self:flex-start;padding:2rem 1.5rem;display:flex;position:sticky;top:2rem;box-shadow:0 4px 15px -3px #0000000d}.sidebar h3{color:#0f172a;border-bottom:1px solid #e2e8f0;margin-bottom:1.5rem;padding-bottom:1rem;font-size:1.2rem}.lesson-list{flex-direction:column;gap:.6rem;list-style:none;display:flex}.lesson-list li{cursor:pointer;color:#475569;background-color:#f8fafc;border-left:4px solid #0000;border-radius:8px;padding:.8rem 1.2rem;font-size:.95rem;transition:all .2s}.lesson-list li:hover{background-color:#f1f5f9}.lesson-list li.active{color:#0369a1;background-color:#e0f2fe;border-left:4px solid #0284c7;font-weight:600}.content-area{background:#fff;border-radius:12px;flex-direction:column;flex:1;min-width:0;padding:3rem 4rem;display:flex;box-shadow:0 4px 15px -3px #0000000d}.content-area h1{color:#0f172a;letter-spacing:-.5px;margin-bottom:2rem;font-size:2.4rem;line-height:1.2}.lesson-content h2{color:#1e293b;border-bottom:2px solid #f1f5f9;margin-top:3.5rem;margin-bottom:1.5rem;padding-bottom:.5rem;font-size:1.8rem}.lesson-content h3{color:#334155;margin-top:2.5rem;margin-bottom:1rem;font-size:1.4rem}.lesson-content p{color:#475569;margin-bottom:1.5rem;font-size:1.1rem}.lesson-content ul,.lesson-content ol{color:#475569;background-color:#f8fafc;border-radius:8px;margin-bottom:2rem;padding:1.5rem 1.5rem 1.5rem 3rem}.lesson-content li{margin-bottom:.8rem;padding-left:.5rem}.info-box{color:#92400e;background-color:#fef3c7;border-left:5px solid #f59e0b;border-radius:0 8px 8px 0;margin:2.5rem 0;padding:1.5rem;font-size:1.05rem}.info-box strong{color:#b45309}.content-img{object-fit:cover;border-radius:12px;width:100%;max-width:100%;max-height:450px;margin:2.5rem 0;display:block;box-shadow:0 10px 25px #00000014}.contact-form{flex-direction:column;gap:1.5rem;max-width:600px;margin-top:2rem;display:flex}.form-group{flex-direction:column;gap:.5rem;display:flex}.form-group label{color:#334155;font-weight:600}.form-group input,.form-group textarea{border:1px solid #cbd5e1;border-radius:8px;padding:1rem;font-family:inherit;font-size:1rem;transition:border-color .3s}.form-group input:focus,.form-group textarea:focus{border-color:#38bdf8;outline:none;box-shadow:0 0 0 3px #38bdf833}.contact-form button{color:#fff;cursor:pointer;background-color:#0284c7;border:none;border-radius:8px;margin-top:1rem;padding:1rem;font-size:1.1rem;font-weight:600;transition:background .3s}.contact-form button:hover{background-color:#0369a1}.adsense-banner,.adsense-in-article{color:#94a3b8;text-align:center;background-color:#f1f5f9;border:2px dashed #cbd5e1;border-radius:8px;justify-content:center;align-items:center;margin:2rem auto;font-size:.9rem;display:flex}.adsense-banner{width:100%;max-width:728px;height:90px}.adsense-in-article{width:100%;height:250px;margin:3rem 0}.footer{color:#94a3b8;text-align:center;background-color:#0f172a;margin-top:auto;padding:2.5rem 1.5rem;font-size:.9rem}@media (width<=1024px){.main-layout{gap:1.5rem;padding:2rem 1rem}.sidebar{flex:0 0 280px}.content-area{padding:2.5rem 2rem}}@media (width<=768px){.header{flex-direction:column;gap:1rem;padding:1.2rem 1rem}.top-nav{flex-wrap:wrap;justify-content:center;gap:.5rem;width:100%}.top-nav button{background-color:#ffffff0d;flex:auto;padding:.6rem 1rem;font-size:.85rem}.main-layout{flex-direction:column;gap:1.5rem;padding:1rem}.sidebar{width:100%;box-shadow:none;border:1px solid #e2e8f0;border-radius:12px;padding:1.2rem;position:static}.sidebar h3{border-bottom:none;margin-bottom:1rem;padding-bottom:0;font-size:1.1rem}.lesson-list{scroll-snap-type:x mandatory;flex-direction:row;align-items:stretch;gap:1rem;padding-bottom:.5rem;overflow-x:auto}.lesson-list::-webkit-scrollbar{display:none}.lesson-list{-ms-overflow-style:none;scrollbar-width:none}.lesson-list li{scroll-snap-align:start;white-space:normal;color:#475569;background-color:#f8fafc;border-bottom:4px solid #0000;border-left:none;border-radius:8px;flex:0 0 240px;align-items:center;padding:1rem 1.2rem;font-size:.95rem;display:flex}.lesson-list li.active{color:#0369a1;background-color:#e0f2fe;border-bottom:4px solid #0284c7;font-weight:600}.content-area{padding:1.5rem 1.2rem}.content-area h1{margin-bottom:1.5rem;font-size:1.8rem}.lesson-content h2{margin-top:2rem;font-size:1.5rem}.lesson-content h3{font-size:1.25rem}.lesson-content p{font-size:1rem}.lesson-content ul,.lesson-content ol{padding:1.2rem 1.2rem 1.2rem 2.2rem}.info-box{margin:2rem 0;padding:1.2rem;font-size:.95rem}.adsense-banner{height:50px;margin:1rem auto}}