:root{--color-primary:#4b6cb7;--color-accent:#007bff;--color-accent-dark:#0056b3;--color-danger:#dc3545;--color-success:#198754;--color-bg:#f4f7f6;--color-main:#f5f5f5;--color-text:#333;--color-muted:#6c757d;--color-border:#ccc}*{box-sizing:border-box}html,body{margin:0;padding:0}body{background-color:var(--color-bg);color:var(--color-text);font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica,Arial,sans-serif;line-height:1.5}.app{flex-direction:column;min-height:100vh;display:flex}.app-header{z-index:10;background-color:var(--color-primary);color:#fff;justify-content:space-between;align-items:center;padding:20px;display:flex;position:sticky;top:0;box-shadow:0 2px 4px #0000001a}.nav-list{flex-wrap:wrap;justify-content:center;align-items:center;margin:0;padding:0;list-style:none;display:flex}.nav-item{margin:0 15px}.nav-link{color:#fff;font-weight:700;text-decoration:none}.nav-button{cursor:pointer;font:inherit;background:0 0;border:none;padding:0;font-weight:700}.nav-user{color:#ffffffd9;font-style:italic}.app-main{background:var(--color-main);flex:1;justify-content:center;align-items:center;padding:20px;display:flex}.app-footer{background-color:var(--color-primary);color:#fff;text-align:center;padding:16px 0}.app-footer p{margin:0}.container{background:#fff;border-radius:8px;width:100%;max-width:500px;padding:40px;box-shadow:0 4px 12px #0000001a}h1{text-align:center;color:var(--color-text);margin-top:0}.form-group{margin-bottom:20px}.form-group label{color:#555;margin-bottom:8px;font-weight:600;display:block}.form-group input{border:1px solid var(--color-border);width:100%;font:inherit;border-radius:4px;padding:10px}.form-group input:focus{outline:2px solid var(--color-accent);outline-offset:1px}.form-group input[aria-invalid=true]{border-color:var(--color-danger)}.form-footer{text-align:center;color:var(--color-muted);margin:20px 0 0}.form-footer a{color:var(--color-accent)}.btn{background-color:var(--color-accent);color:#fff;cursor:pointer;border:none;border-radius:4px;width:100%;padding:12px;font-family:inherit;font-size:16px;transition:background-color .2s}.btn:hover:not(:disabled){background-color:var(--color-accent-dark)}.btn:disabled{opacity:.6;cursor:not-allowed}.task-form-btn{margin-top:10px}.btn-small{width:auto;padding:5px 10px;font-size:14px}.btn-secondary{color:var(--color-text);background-color:#e9ecef}.btn-secondary:hover:not(:disabled){background-color:#d6dbe0}.btn-danger{background-color:var(--color-danger)}.btn-danger:hover:not(:disabled){background-color:#b02a37}.alert{border:1px solid #0000;border-radius:4px;justify-content:space-between;align-items:flex-start;gap:12px;margin-bottom:16px;padding:12px 14px;display:flex}.alert-error{color:#7f1d1d;background:#fdecea;border-color:#f5c2c7}.alert-success{color:#14532d;background:#e6f4ea;border-color:#badbcc}.alert-info{color:#084298;background:#e7f1ff;border-color:#b6d4fe}.alert-close{cursor:pointer;color:inherit;background:0 0;border:none;padding:0 4px;font-size:1.2rem;line-height:1}.loading,.task-empty{text-align:center;color:var(--color-muted)}.task-list{margin:0;padding:0;list-style:none}.task-item{border-bottom:1px solid #eee;align-items:center;gap:12px;padding:15px 0;display:flex}.task-item:last-child{border-bottom:none}.task-check{cursor:pointer;width:18px;height:18px;accent-color:var(--color-success);flex-shrink:0}.task-body{flex-direction:column;flex:1;gap:2px;min-width:0;display:flex}.task-title{word-break:break-word}.task-description{color:var(--color-muted);word-break:break-word;font-size:.9rem}.task-item.completed .task-title{color:#aaa;text-decoration:line-through}.task-actions{flex-shrink:0;gap:8px;display:flex}.task-edit{flex-wrap:wrap;flex:1;align-items:center;gap:8px;display:flex}.task-edit input{border:1px solid var(--color-border);min-width:140px;font:inherit;border-radius:4px;flex:1;padding:8px 10px}@media (width<=600px){.container{padding:20px}.app-main{align-items:flex-start;padding:12px}.task-item{flex-wrap:wrap}.task-actions{justify-content:flex-end;width:100%}}