:root{--bg: #f4f6fa;--surface: #ffffff;--border: #e3e8f0;--text: #1f2733;--text-secondary: #64748b;--primary: #4f6ef7;--primary-dark: #3b55d6;--success: #16a34a;--danger: #dc2626;--warning: #d97706;--radius: 12px;--shadow: 0 1px 3px rgba(15, 23, 42, .08), 0 4px 16px rgba(15, 23, 42, .06)}*{box-sizing:border-box;margin:0;padding:0}html,body{height:100%}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,PingFang SC,Hiragino Sans GB,Microsoft YaHei,sans-serif;background:var(--bg);color:var(--text);line-height:1.6}#app{min-height:100%}.app-shell{max-width:960px;margin:0 auto;padding:32px 20px 48px}.app-header{text-align:center;margin-bottom:24px}.app-title{font-size:28px;font-weight:700;letter-spacing:.5px}.app-subtitle{color:var(--text-secondary);margin-top:4px;font-size:14px}.perm-banner{display:flex;align-items:center;gap:12px;background:#fff7ed;border:1px solid #fed7aa;border-radius:var(--radius);padding:10px 16px;margin-bottom:20px;font-size:14px;color:#9a3412}.perm-banner .btn{margin-left:auto}.btn{border:none;border-radius:8px;cursor:pointer;font-size:14px;padding:8px 16px;transition:background .15s ease,transform .1s ease;font-family:inherit}.btn:active{transform:scale(.98)}.btn-primary{background:var(--primary);color:#fff}.btn-primary:hover{background:var(--primary-dark)}.btn-ghost{background:transparent;color:var(--text-secondary);border:1px solid var(--border)}.btn-ghost:hover{background:#f1f5f9}.btn-danger{color:var(--danger)}.btn-danger:hover{background:#fef2f2}.btn-block{width:100%;padding:12px;font-size:15px}.btn-small{padding:4px 12px;font-size:13px}.btn-icon{width:32px;height:32px;padding:0;display:inline-flex;align-items:center;justify-content:center;background:transparent;color:var(--text-secondary);border-radius:8px}.btn-icon:hover{background:#f1f5f9}.card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow)}.stats-bar{display:grid;grid-template-columns:repeat(4,1fr);gap:12px;margin-bottom:20px}.stat{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:14px;text-align:center}.stat-num{display:block;font-size:26px;font-weight:700;color:var(--primary)}.stat-num.stat-overdue{color:var(--danger)}.stat-label{font-size:12px;color:var(--text-secondary)}.content-grid{display:grid;grid-template-columns:320px 1fr;gap:20px;align-items:start}.side-col{position:sticky;top:20px}.list-col{min-width:0}.task-form-section{margin-bottom:20px}.task-form{padding:20px}.form-title{font-size:16px;margin-bottom:16px}.form-field{margin-bottom:14px}.form-field label{display:block;font-size:13px;color:var(--text-secondary);margin-bottom:6px}.required{color:var(--danger)}.form-field input[type=text],.form-field input[type=search],.form-field input[type=datetime-local],.form-field textarea{width:100%;border:1px solid var(--border);border-radius:8px;padding:9px 12px;font-size:14px;font-family:inherit;background:#fff;color:var(--text);transition:border-color .15s ease}.form-field input:focus,.form-field textarea:focus{outline:none;border-color:var(--primary)}.form-row{display:grid;grid-template-columns:1fr 1fr;gap:12px}.priority-select{display:flex;gap:8px}.priority-option{flex:1;padding:8px;border:1px solid var(--border);border-radius:8px;background:#fff;cursor:pointer;font-size:13px;color:var(--text-secondary);font-family:inherit}.priority-option.active{border-color:var(--primary);color:var(--primary);background:#eef2ff;font-weight:600}.form-error{color:var(--danger);font-size:13px;margin-bottom:12px}.form-actions{display:flex;justify-content:flex-end;gap:8px;margin-top:4px}.filter-bar{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-bottom:16px;flex-wrap:wrap}.view-tabs{display:flex;background:var(--surface);border:1px solid var(--border);border-radius:10px;overflow:hidden}.view-tab{border:none;background:transparent;padding:8px 16px;font-size:14px;cursor:pointer;color:var(--text-secondary);font-family:inherit}.view-tab.active{background:var(--primary);color:#fff}.search-box{display:flex;align-items:center;gap:6px;background:var(--surface);border:1px solid var(--border);border-radius:10px;padding:0 12px;flex:0 1 260px}.search-box input{border:none;outline:none;padding:8px 0;font-size:14px;width:100%;background:transparent;color:var(--text);font-family:inherit}.search-icon{font-size:14px}.task-list{list-style:none;display:flex;flex-direction:column;gap:10px}.task-item{display:flex;align-items:flex-start;gap:12px;padding:14px 16px;transition:border-color .15s ease}.task-item.priority-high{border-left:4px solid var(--danger)}.task-check{width:22px;height:22px;min-width:22px;border-radius:50%;border:2px solid var(--border);background:#fff;cursor:pointer;color:#fff;font-size:12px;display:flex;align-items:center;justify-content:center;margin-top:2px}.task-check.checked{background:var(--success);border-color:var(--success)}.task-content{flex:1;min-width:0}.task-head{display:flex;align-items:center;gap:8px}.task-title{font-size:15px;font-weight:600;word-break:break-all}.task-item.completed .task-title{text-decoration:line-through;color:var(--text-secondary)}.priority-badge{font-size:11px;padding:1px 8px;border-radius:999px;font-weight:600}.priority-badge.low{background:#ecfdf5;color:#047857}.priority-badge.medium{background:#fef9c3;color:#a16207}.priority-badge.high{background:#fee2e2;color:#b91c1c}.task-desc{font-size:13px;color:var(--text-secondary);margin-top:4px;word-break:break-all}.task-meta{display:flex;flex-wrap:wrap;gap:10px;margin-top:6px}.meta-time{font-size:12px;color:var(--text-secondary)}.overdue-badge{display:inline-block;font-size:11px;background:#fee2e2;color:var(--danger);border-radius:999px;padding:0 8px;margin-left:6px;font-weight:600}.done-badge{font-size:11px;background:#dcfce7;color:var(--success);border-radius:999px;padding:0 8px;font-weight:600}.task-actions{display:flex;gap:4px}.empty-tip{text-align:center;color:var(--text-secondary);padding:48px 16px;border:1px dashed var(--border);border-radius:var(--radius);font-size:14px}.app-footer{text-align:center;color:var(--text-secondary);font-size:12px;margin-top:40px}@media (max-width: 720px){.content-grid{grid-template-columns:1fr}.side-col{position:static}.stats-bar{grid-template-columns:repeat(2,1fr)}.form-row{grid-template-columns:1fr}}