*{box-sizing:border-box;padding:0;margin:0}body,html{max-width:100vw;overflow-x:hidden;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen,Ubuntu,Cantarell,Fira Sans,Droid Sans,Helvetica Neue,sans-serif;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}body{background:linear-gradient(135deg,#667eea,#764ba2);min-height:100vh;padding:2rem}.container{max-width:1300px;margin:0 auto;background:#fff;border-radius:12px;padding:2rem 2.5rem;box-shadow:0 20px 60px rgba(0,0,0,.3)}h1{color:#333;margin-bottom:2rem;text-align:center}.video-container{width:100%;max-width:800px;margin:0 auto;background:#000;border-radius:8px;overflow:hidden}video{width:100%;height:auto;display:block}.video-list{display:grid;grid-gap:.75rem;gap:.75rem;margin-top:1rem}.video-item{padding:.75rem 1rem;background:#f5f5f5;border-radius:8px;cursor:pointer;transition:all .3s ease;border:2px solid transparent}.video-item:hover{background:#e8e8e8;border-color:#667eea;transform:translateY(-2px)}.video-item.active{background:#667eea;color:#fff;border-color:#764ba2}.layout{display:grid;grid-template-columns:320px 1fr;grid-gap:1.5rem;gap:1.5rem;margin-top:1.5rem}.sidebar{background:#f7f7fa;border-radius:10px;padding:1.25rem;box-shadow:0 10px 30px rgba(0,0,0,.08);height:-moz-fit-content;height:fit-content;display:grid;grid-gap:1.25rem;gap:1.25rem}.main-panel{background:#fafafa;border-radius:10px;padding:1rem;box-shadow:inset 0 0 0 1px #eee,0 10px 30px rgba(0,0,0,.05)}.upload-card h2,.video-list h2{margin-bottom:.35rem}.upload-card p{color:#555;margin-bottom:.75rem;font-size:.95rem}.upload-card input[type=file]{width:100%}.notice{padding:1rem;border-radius:8px;margin:.75rem 0}.notice.success{background:#eefaf0;color:#1b7f3f;border:1px solid #c6e7d0}.empty-state{background:#fff;border-radius:8px;padding:2rem;text-align:center;color:#666;box-shadow:inset 0 0 0 1px #eee}@media (max-width:768px){body{padding:1rem}.layout{grid-template-columns:1fr}}.error{color:#e74c3c;padding:1rem;background:#fee;border-radius:8px;margin:1rem 0}.loading{text-align:center;padding:2rem;color:#666}