*{margin:0;padding:0;box-sizing:border-box;}body{background:linear-gradient(145deg,#f9f3e8 0%,#fef7ef 100%);font-family:'Segoe UI','PingFang SC',Roboto,'Helvetica Neue',sans-serif;min-height:100vh;display:flex;flex-direction:column;align-items:center;padding:2rem 1.5rem 0 1.5rem;color:#2e3b4e;}.course-wrapper{max-width:1280px;width:100%;background:rgba(255,250,240,0.7);backdrop-filter:blur(2px);border-radius:48px 48px 32px 32px;padding:2rem 2rem 1.5rem 2rem;box-shadow:0 20px 40px -12px rgba(0,20,30,0.15),0 8px 24px -6px rgba(255,215,150,0.2);border:1px solid rgba(255,235,200,0.5);}.header-title{display:flex;align-items:baseline;justify-content:space-between;flex-wrap:wrap;margin-bottom:2rem;border-bottom:3px dashed #fbcb9a;padding-bottom:0.75rem;}.header-title h1{font-size:2.4rem;font-weight:700;letter-spacing:-0.3px;background:linear-gradient(135deg,#f78b6b,#f7b26b);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text;text-shadow:0 2px 8px rgba(247,139,107,0.2);display:inline-flex;align-items:center;gap:0.5rem;}.header-title h1::before{content:"📘";font-size:2.2rem;-webkit-text-fill-color:initial;background:none;}.header-badge{background:#ffe6c7;padding:0.4rem 1.2rem;border-radius:40px;font-weight:600;font-size:0.9rem;color:#a55f3a;box-shadow:inset 0 -2px 0 #eebb8b;border:1px solid #fad6ae;backdrop-filter:blur(2px);}.header-badge span{background:#f7b26b;color:#2e2b26;border-radius:30px;padding:0.1rem 0.7rem;margin-left:0.4rem;font-weight:700;}.catalog-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:1rem;margin:1.2rem 0 1.8rem 0;}.chapter-card{background:#fffffffa;border-radius:28px;padding:1rem 1.2rem 1rem 1.2rem;box-shadow:0 6px 14px rgba(235,195,145,0.15),0 2px 4px rgba(0,0,0,0.02);transition:all 0.2s ease;border:1px solid #f7e3cf;display:flex;flex-direction:column;backdrop-filter:blur(2px);background:rgba(255,250,242,0.9);}.chapter-card:hover{transform:translateY(-4px);box-shadow:0 14px 24px -8px rgba(215,150,90,0.25);border-color:#fbc28b;background:#fffcf5;}.chapter-card a{text-decoration:none;color:inherit;display:flex;flex-direction:column;height:100%;}.chapter-number{font-size:0.8rem;font-weight:700;color:#d68f5c;letter-spacing:0.3px;background:#f7e5d4;display:inline-block;width:fit-content;padding:0.1rem 0.9rem;border-radius:30px;margin-bottom:0.5rem;border:1px solid #efd5bb;}.chapter-title{font-weight:700;font-size:1.1rem;line-height:1.3;color:#2c3a4a;margin-bottom:0.3rem;display:flex;align-items:center;gap:6px;}.chapter-title .emoji-bullet{font-size:1.2rem;filter:drop-shadow(0 2px 2px rgba(247,150,70,0.2));}.chapter-topics{font-size:0.8rem;color:#5f6b7a;line-height:1.4;margin-top:0.2rem;padding-left:0.2rem;border-left:3px solid #fad2ae;padding-left:0.6rem;opacity:0.85;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden;}.footer-area{margin-top:1.2rem;padding:1rem 0 0.2rem 0;border-top:2px dotted #f5cfb0;display:flex;justify-content:center;font-size:1rem;font-weight:500;color:#7f6a58;letter-spacing:1px;}.footer-area span{background:#faeadc;padding:0.2rem 2rem;border-radius:40px;box-shadow:inset 0 -1px 0 #eacbad;}@media (max-width:640px){.course-wrapper{padding:1.5rem 1rem;}.header-title h1{font-size:1.8rem;}.catalog-grid{grid-template-columns:1fr;}.chapter-card{padding:0.9rem 1rem;}}.chapter-card:nth-child(5n+1) .chapter-number{background:#fde3c0;color:#9f6a3e;}.chapter-card:nth-child(5n+2) .chapter-number{background:#d9ecdc;color:#3f7856;}.chapter-card:nth-child(5n+3) .chapter-number{background:#f9d9d9;color:#b14f4f;}.chapter-card:nth-child(5n+4) .chapter-number{background:#d5e4f0;color:#2a6b8a;}.chapter-card:nth-child(5n+5) .chapter-number{background:#f7e0b0;color:#8f6f3a;}.chapter-card a:active{opacity:0.7;}