:root{--bg: #f8f9fa;--card-bg: #ffffff;--text: #333333;--accent: #4361ee;--border: #dee2e6;--input-bg: #ffffff;--radius: 10px}*{margin:0;padding:0;box-sizing:border-box}body{font-family:Segoe UI,system-ui,-apple-system,sans-serif;background:var(--bg);color:var(--text);min-height:100vh}.container{max-width:720px;margin:0 auto;padding:2rem 1rem}h1{text-align:center;margin-bottom:2rem;font-size:2rem;color:var(--accent)}.card{background:var(--card-bg);border:1px solid var(--border);border-radius:var(--radius);padding:1rem;margin-bottom:.75rem;display:flex;align-items:center;gap:1rem;transition:box-shadow .2s}.card:hover{box-shadow:0 2px 12px #0000001a}.card .text{flex:1}.card .text.done{text-decoration:line-through;opacity:.5}.form-row{display:flex;gap:.5rem;margin-bottom:1.5rem}input[type=text]{flex:1;padding:.65rem 1rem;border:1px solid var(--border);border-radius:var(--radius);font-size:1rem;background:var(--input-bg);color:var(--text)}input:focus{outline:2px solid var(--accent);border-color:transparent}button{padding:.65rem 1.2rem;border:none;border-radius:var(--radius);cursor:pointer;font-size:.95rem;font-weight:600;transition:opacity .2s}button:hover{opacity:.85}.btn-add{background:var(--accent);color:#fff}.btn-toggle{background:transparent;color:var(--accent);text-decoration:underline;font-size:.85rem}.btn-delete{background:transparent;color:#e74c3c;font-size:.85rem}.empty{text-align:center;padding:2rem;opacity:.5}