*{margin:0;padding:0;box-sizing:border-box}body{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,sans-serif;background:#f5f5f5;color:#333;transition:background .3s,color .3s}body.dark{background:#1a1a1a;color:#e0e0e0}.theme-toggle{position:fixed;bottom:30px;right:30px;width:50px;height:50px;border-radius:50%;background:#0096c8;color:#fff;display:flex;align-items:center;justify-content:center;cursor:pointer;z-index:100}.activity-layout{display:flex;max-width:1000px;margin:30px auto;padding:0 20px;gap:30px}.activity-sidebar{flex:0 0 220px}.activity-nav{display:flex;flex-direction:column;gap:8px}.nav-btn{background:#fff;border:2px solid #eee;padding:14px;border-radius:8px;text-align:left;font-size:.95rem;font-weight:600;color:#333;cursor:pointer;display:flex;align-items:center;gap:10px}.dark .nav-btn{background:#2a2a2a;border-color:#444;color:#e0e0e0}.nav-btn.active{background:linear-gradient(90deg,#0096c8,#00d4aa);color:#fff;border-color:#0096c8}.activity-content{flex:1}.activity-card{background:#fff;border:2px solid #eee;border-radius:8px;padding:2rem;display:none}.dark .activity-card{background:#2a2a2a;border-color:#444}.activity-card.active{display:block}.card-title{font-size:1.8rem;margin-bottom:1rem;color:#333}.dark .card-title{color:#e0e0e0}.card-desc{color:#666;margin-bottom:1.5rem}.dark .card-desc{color:#aaa}.card-content{color:#555}.dark .card-content{color:#ccc}.action-btn{display:inline-block;padding:10px 22px;background:linear-gradient(90deg,#0096c8,#00d4aa);color:#fff;text-decoration:none;border-radius:6px;border:none;cursor:pointer;margin-top:15px}.search-main{max-width:800px;margin:60px auto;padding:0 20px}.search-header{text-align:center;margin-bottom:40px}.search-header h1{font-size:2.8rem;margin-bottom:15px;background:linear-gradient(90deg,#0096c8,#00d4aa);-webkit-background-clip:text;-webkit-text-fill-color:transparent}.search-box{display:flex;gap:10px;margin:30px 0}.search-box input{flex:1;padding:15px;border:2px solid #0096c8;border-radius:8px;font-size:1.1rem;background:#fff;color:#333}.dark .search-box input{background:#2a2a2a;color:#e0e0e0}.search-btn{background:linear-gradient(90deg,#0096c8,#00d4aa);color:#fff;border:none;padding:15px 30px;border-radius:8px;cursor:pointer}.search-keys{display:flex;flex-wrap:wrap;gap:10px;margin:15px 0;justify-content:center}.key-btn{padding:6px 12px;background:rgba(0,150,200,0.1);color:#0096c8;border-radius:6px;cursor:pointer}.search-results{margin-top:40px}.result-item{background:#fff;padding:20px;border-radius:12px;margin-bottom:15px;border:2px solid #eee}.dark .result-item{background:#2a2a2a;border-color:#444}.result-item:hover{border-color:#0096c8}.result-title{font-size:1.2rem;margin-bottom:8px;color:#0096c8}.result-desc{color:#333;margin-bottom:10px}.dark .result-desc{color:#e0e0e0}.result-link{color:#0096c8;text-decoration:none}.no-results{padding:40px;text-align:center;color:#888}.main-container{max-width:900px;margin:120px auto 60px;padding:0 20px}.page-header{text-align:center;margin-bottom:40px}.page-header h1{font-size:2.8rem;margin-bottom:15px;background:linear-gradient(90deg,#0096c8,#00d4aa);-webkit-background-clip:text;-webkit-text-fill-color:transparent}.page-header p{color:#666;font-size:1.1rem}.platform-card{background:#fff;padding:1.5rem;border-radius:8px;margin-bottom:1.5rem;border:2px solid #eee;display:flex;align-items:center;gap:1rem}.dark .platform-card{background:#2a2a2a;border-color:#444}.platform-logo{width:48px;height:48px;object-fit:contain;flex-shrink:0}.platform-content{flex:1}.platform-title{font-size:1.4rem;margin-bottom:.3rem;color:#333}.dark .platform-title{color:#e0e0e0}.platform-desc{color:#666;margin-bottom:.5rem}.dark .platform-desc{color:#aaa}.platform-btn{display:inline-block;padding:6px 16px;background:linear-gradient(90deg,#0096c8,#00d4aa);color:#fff;text-decoration:none;border-radius:6px;font-weight:500;font-size:.9rem}.tutorial-card{background:#fff;padding:1.5rem;border-radius:8px;margin-bottom:1.5rem;border:2px solid #eee}.dark .tutorial-card{background:#2a2a2a;border-color:#444}.tutorial-icon{font-size:2rem;color:#0096c8;margin-bottom:.8rem}.tutorial-name{font-size:1.3rem;margin-bottom:.8rem;color:#333}.dark .tutorial-name{color:#e0e0e0}.tutorial-desc{color:#666;margin-bottom:1rem}.dark .tutorial-desc{color:#aaa}.tutorial-btn{display:inline-block;padding:6px 18px;background:linear-gradient(90deg,#0096c8,#00d4aa);color:#fff;text-decoration:none;border-radius:6px;font-weight:500}.section-title{font-size:2.8rem;margin-bottom:15px;background:linear-gradient(90deg,#0096c8,#00d4aa);-webkit-background-clip:text;-webkit-text-fill-color:transparent;text-align:center}.section-subtitle{color:#666;font-size:1.1rem;text-align:center;margin-bottom:2rem}@media(max-width:900px){.activity-layout{flex-direction:column}.activity-sidebar{width:100%}.activity-nav{flex-direction:row;flex-wrap:wrap}.nav-btn{flex:1;min-width:140px}}@media(max-width:600px){.activity-nav{flex-direction:column}.nav-btn{min-width:100%}}