*{box-sizing:border-box}body{margin:0;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen,Ubuntu,Cantarell,Open Sans,Helvetica Neue,sans-serif;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;background:#f5f5f5}a{color:inherit}button{font-family:inherit}.landing{min-height:100vh;display:flex;flex-direction:column;align-items:center;justify-content:center;padding:2rem}.landing h1{font-size:3rem;margin-bottom:.5rem;color:#1a1a2e}.subtitle{color:#666;margin-bottom:3rem;font-size:1.2rem}.role-cards{display:flex;gap:2rem;flex-wrap:wrap;justify-content:center}.role-card{display:flex;flex-direction:column;align-items:center;padding:2.5rem 3rem;border-radius:16px;text-decoration:none;transition:transform .2s,box-shadow .2s;min-width:280px}.role-card:hover{transform:translateY(-4px);box-shadow:0 12px 24px #00000026}.role-card.tutor{background:linear-gradient(135deg,#667eea,#764ba2);color:#fff}.role-card.tutee{background:linear-gradient(135deg,#11998e,#38ef7d);color:#fff}.role-icon{width:80px;height:80px;border-radius:50%;background:#fff3;display:flex;align-items:center;justify-content:center;font-size:2.5rem;font-weight:700;margin-bottom:1.5rem}.role-card h2{margin:0 0 .5rem;font-size:1.5rem}.role-card p{margin:0;opacity:.9;text-align:center}.video-container{display:flex;flex-direction:column;height:100vh;background:#1a1a2e;padding:1rem}.video-grid{flex:1;display:grid;grid-template-columns:repeat(auto-fit,minmax(400px,1fr));gap:1rem;padding:1rem}.video-tile{position:relative;background:#16213e;border-radius:12px;overflow:hidden;aspect-ratio:16 / 9;display:flex;align-items:center;justify-content:center}.video-tile.self{border:2px solid #667eea}.video-tile video,.video-tile canvas,.video-canvas{width:100%;height:100%;object-fit:cover}.video-canvas video-player,.video-canvas video-player-container{width:100%!important;height:100%!important}.video-placeholder{position:absolute;color:#666;font-size:1.2rem;z-index:1}.participant-name{position:absolute;bottom:.5rem;left:.5rem;background:#0009;color:#fff;padding:.25rem .75rem;border-radius:4px;font-size:.875rem}.remove-btn{position:absolute;top:.5rem;right:.5rem;width:28px;height:28px;border-radius:50%;border:none;background:#e74c3c;color:#fff;cursor:pointer;font-weight:700;opacity:0;transition:opacity .2s}.video-tile:hover .remove-btn{opacity:1}.controls{display:flex;justify-content:center;gap:1rem;padding:1rem;background:#16213e;border-radius:12px;margin-top:1rem}.control-btn{padding:.75rem 1.5rem;border:none;border-radius:8px;cursor:pointer;font-size:1rem;transition:background .2s,transform .1s;background:#3d5a80;color:#fff}.control-btn:hover{transform:scale(1.02)}.control-btn.active{background:#667eea}.control-btn.host-control{background:#f39c12}.control-btn.danger{background:#e74c3c}.participants-info{text-align:center;color:#888;padding:.5rem;font-size:.875rem}.session-page{min-height:100vh;display:flex;flex-direction:column;align-items:center;justify-content:center;padding:2rem;background:#f5f5f5}.back-link{position:absolute;top:2rem;left:2rem;color:#667eea;text-decoration:none;font-weight:500}.back-link:hover{text-decoration:underline}.join-card{background:#fff;padding:2.5rem;border-radius:16px;box-shadow:0 4px 24px #0000001a;width:100%;max-width:400px}.join-card h1{margin:0 0 .5rem;font-size:1.75rem;color:#1a1a2e}.join-card>p{color:#666;margin:0 0 2rem}.form-group{margin-bottom:1.5rem}.form-group label{display:block;margin-bottom:.5rem;font-weight:500;color:#333}.form-group input{width:100%;padding:.75rem;border:2px solid #e0e0e0;border-radius:8px;font-size:1rem;transition:border-color .2s}.form-group input:focus{outline:none;border-color:#667eea}.hint{display:block;margin-top:.25rem;font-size:.875rem;color:#888}.join-btn{width:100%;padding:1rem;border:none;border-radius:8px;font-size:1.1rem;font-weight:600;cursor:pointer;transition:opacity .2s,transform .1s;color:#fff}.join-btn:hover:not(:disabled){transform:scale(1.02)}.join-btn:disabled{opacity:.6;cursor:not-allowed}.tutor-btn{background:linear-gradient(135deg,#667eea,#764ba2)}.tutee-btn{background:linear-gradient(135deg,#11998e,#38ef7d)}.error-message{background:#fee;color:#c00;padding:.75rem;border-radius:8px;margin-bottom:1.5rem;font-size:.875rem}