:root{--bg-app:#0a0f1e;--bg-panel:#0f172a;--bg-deep:#0b1220;--bg-elevated:#172033;--bg-surface:#1e293b;--bg-hover:#273449;--bg-accent:#1e3a5f;--bg-success:#0d2d1a;--border:#1e293b;--border-strong:#334155;--text-1:#f1f5f9;--text-2:#e2e8f0;--text-3:#94a3b8;--text-4:#8494a9;--text-5:#64748b;--text-6:#475569;--text-primary:var(--text-1);--text-secondary:var(--text-2);--text-muted:var(--text-4);--text-disabled:var(--text-5);--text-on-accent:#fff;--accent-blue-text:#60a5fa;--accent-blue-solid:#2563eb;--accent-blue-bg:#1e3a5f;--accent-blue-border:#3b82f6;--accent-green-text:#4ade80;--accent-green-solid:#15803d;--accent-green-bg:#0d2d1a;--accent-green-border:#22c55e;--accent-purple-text:#c084fc;--accent-purple-solid:#7c3aed;--accent-purple-bg:#2e1065;--accent-purple-border:#a855f7;--accent-amber-text:#fbbf24;--accent-amber-solid:#b45309;--accent-amber-bg:#2a2008;--accent-amber-border:#f59e0b;--accent-red-text:#f87171;--accent-red-solid:#dc2626;--accent-red-bg:#2a1014;--accent-red-border:#ef4444;--focus-ring:var(--accent-blue-border);--bg-success-tint:#22c55e14;--overlay:#0009;--tooltip-bg:#0d1b2e;--tooltip-border:#1e3a5f;--tooltip-shadow:0 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var(--border);flex-shrink:0;align-items:center;gap:10px;padding:6px 12px;display:flex}.run-tests-btn{background:var(--bg-success);color:#4ade80;cursor:pointer;letter-spacing:.3px;border:1px solid #22c55e66;border-radius:6px;align-items:center;gap:5px;padding:4px 14px;font-family:inherit;font-size:11.5px;font-weight:700;transition:background .15s,border-color .15s,box-shadow .15s;display:inline-flex}.run-tests-btn:hover{background:#14391f;border-color:#22c55e;box-shadow:0 0 8px #22c55e30}.test-toolbar-hint{color:var(--text-disabled);align-items:center;gap:7px;font-size:11px;display:inline-flex}.run-tests-kbd{color:var(--text-4);background:var(--bg-deep);border:1px solid var(--border);white-space:nowrap;border-bottom-width:2px;border-radius:4px;padding:3px 6px;font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:11px;line-height:1}.submit-btn{background:var(--submit-btn-bg);border:1px solid 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strong{color:#22c55e;font-weight:600}.practice-num-badge{letter-spacing:0;border-radius:50%;flex-shrink:0;justify-content:center;align-items:center;width:20px;min-width:20px;height:20px;font-size:11px;font-weight:700;line-height:1;display:inline-flex}.practice-num-badge--unseen{background:var(--bg-surface);color:var(--text-muted);border:1px solid var(--border-strong)}.practice-num-badge--attempted{background:var(--num-badge-attempted-bg);color:var(--num-badge-attempted-text);border:1px solid var(--num-badge-attempted-border);box-shadow:var(--num-badge-attempted-shadow)}.practice-num-badge--solved{background:var(--num-badge-solved-bg);color:var(--num-badge-solved-text);border:1px solid var(--num-badge-solved-border);box-shadow:var(--num-badge-solved-shadow)}.completion-overlay{z-index:400;cursor:pointer;background:#0000008c;justify-content:center;align-items:center;animation:.25s overlayFadeIn;display:flex;position:fixed;inset:0}@keyframes 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var(--border-strong);color:var(--text-3);cursor:pointer;background:0 0;border-radius:5px;align-items:center;gap:5px;padding:4px 10px;font-size:12px;transition:color .15s,border-color .15s,background .15s;display:inline-flex}.solution-drawer-copy:hover{color:var(--text-2);border-color:var(--text-muted);background:var(--bg-surface)}.solution-drawer-copy--copied{color:#4ade80;background:#052e16;border-color:#166534}.sandbox-boot-hint{background:var(--bg-panel);border:1px solid var(--border);max-width:calc(100% - 32px);color:var(--text-4);text-align:center;white-space:normal;pointer-events:none;z-index:5;border-radius:14px;padding:6px 14px;font-size:12px;position:absolute;bottom:14px;left:50%;transform:translate(-50%)}.preview-stale-overlay{-webkit-backdrop-filter:blur(3px);backdrop-filter:blur(3px);z-index:10;cursor:pointer;background:#080c18c7;justify-content:center;align-items:center;display:flex;position:absolute;inset:0}.preview-stale-card{background:var(--bg-panel);border:1px solid 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8px}.practice-filter-row1{align-items:center;gap:4px;display:flex}.practice-filter-toggle{border:1px solid var(--border);color:var(--text-muted);cursor:pointer;background:0 0;border-radius:5px;flex-shrink:0;justify-content:center;align-items:center;margin-left:auto;padding:4px 6px;transition:color .15s,border-color .15s,background .15s;display:inline-flex}.practice-filter-toggle:hover{border-color:var(--border-strong);color:var(--text-3)}.practice-filter-toggle--open{background:var(--bg-surface);border-color:var(--border-strong);color:var(--text-2)}.practice-filter-status{flex:1;gap:3px;display:flex}.practice-filter-status-btn{text-transform:uppercase;letter-spacing:.4px;color:var(--filter-status-text);cursor:pointer;background:0 0;border:1px solid #0000;border-radius:5px;flex-direction:column;flex:1;align-items:center;gap:1px;padding:4px 2px;font-size:11px;font-weight:600;line-height:1;transition:background .15s,color .15s,border-color .15s;display:flex}.practice-filter-count{letter-spacing:0;text-transform:none;color:inherit;opacity:.8;font-size:11px;font-weight:700}.practice-filter-status-btn:hover{background:var(--bg-surface);color:var(--text-3)}.practice-filter-status-btn--all.practice-filter-status-btn--active{background:var(--bg-surface);border-color:var(--border-strong);color:var(--text-2)}.practice-filter-status-btn--unseen.practice-filter-status-btn--active{border-color:var(--border-strong);color:var(--text-3);background:#1c2533}.practice-filter-status-btn--attempted.practice-filter-status-btn--active{color:#f59e0b;background:#1f1a0e;border-color:#78350f}.practice-filter-status-btn--solved.practice-filter-status-btn--active{color:#22c55e;background:#0d1f12;border-color:#166534}.practice-filter-diff{gap:4px;display:flex}.practice-filter-diff-chip{border:1px solid var(--border);color:var(--filter-diff-text);cursor:pointer;opacity:.45;background:0 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0;border:none;align-items:center;gap:7px;padding:2px 0;font-family:inherit;font-size:11px;font-weight:600;transition:color .15s;display:inline-flex}.practice-hide-solved:hover:not(:disabled){color:var(--text-3)}.practice-hide-solved--on{color:var(--text-1)}.practice-hide-solved:disabled{opacity:.4;cursor:not-allowed}.practice-hide-solved-box{background:var(--bg-panel);border:1.5px solid #334155;border-radius:4px;justify-content:center;align-items:center;width:14px;height:14px;transition:background .15s,border-color .15s;display:inline-flex}.practice-hide-solved--on .practice-hide-solved-box{background:#22c55e;border-color:#22c55e}.practice-hide-solved--on .practice-hide-solved-box:after{content:"";border:2px solid #07140c;border-width:0 2px 2px 0;width:4px;height:8px;margin-top:-1px;transform:rotate(45deg)}.hints-panel{margin-top:8px;padding-bottom:16px}.hints-divider{background:var(--bg-surface);height:1px;margin-bottom:16px}.hints-list{flex-direction:column;gap:10px;margin-bottom:14px;display:flex}.hint-item{background:var(--bg-panel);border:1px solid var(--border);border-left:3px solid #7c3aed;border-radius:6px;padding:10px 12px;animation:.25s hintReveal}@keyframes hintReveal{0%{opacity:0;transform:translateY(-6px)}to{opacity:1;transform:translateY(0)}}.hint-label{text-transform:uppercase;letter-spacing:.8px;color:#7c3aed;margin-bottom:5px;font-size:11px;font-weight:700}.hint-text{color:var(--text-3);white-space:pre-wrap;margin:0;font-family:inherit;font-size:12.5px;line-height:1.6}.hint-get-btn{color:#a78bfa;cursor:pointer;letter-spacing:.2px;background:0 0;border:1px dashed #4c1d95;border-radius:7px;justify-content:center;align-items:center;gap:6px;width:100%;padding:8px 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form{flex-direction:column;gap:12px;display:flex}.auth-notice{background:var(--bg-accent);color:#93c5fd;border:1px solid #2563eb;border-radius:8px;padding:10px 12px;font-size:12px;line-height:1.5}.auth-notice code{background:#0f2547;border-radius:4px;padding:1px 5px;font-family:monospace}.auth-btn-google{color:#1a1a1a;cursor:pointer;background:#fff;border:none;border-radius:12px;justify-content:center;align-items:center;gap:10px;width:100%;padding:10px 16px;font-size:14px;font-weight:500;transition:background .15s,box-shadow .15s;display:flex}.auth-btn-google:hover:not(:disabled){background:#f5f5f5;box-shadow:0 1px 4px #0003}.auth-btn-google:disabled{opacity:.5;cursor:not-allowed}.auth-divider{color:#4b5563;align-items:center;gap:12px;font-size:12px;display:flex}.auth-divider:before,.auth-divider:after{content:"";background:#2d3748;flex:1;height:1px}.auth-form-group{flex-direction:column;gap:6px;display:flex}.auth-form-label{color:var(--text-3);font-size:12px;font-weight:500}.auth-form-input{background:var(--bg-panel);color:var(--text-1);box-sizing:border-box;border:1px solid #2d3748;border-radius:11px;outline:none;width:100%;padding:11px 13px;font-size:14px;transition:border-color .15s,box-shadow .15s,background .15s}.auth-form-input:focus{background:var(--bg-deep);border-color:#60a5fa;box-shadow:0 0 0 3px #3b82f633,0 0 18px #60a5fa33}.auth-form-input:disabled{opacity:.5;cursor:not-allowed}.auth-msg{border-radius:7px;padding:9px 12px;font-size:13px;line-height:1.4}.auth-msg--error{color:#fca5a5;background:#450a0a;border:1px solid #991b1b}.auth-msg--success{color:#86efac;background:#052e16;border:1px solid #166534}.auth-btn-primary{color:#fff;cursor:pointer;background:linear-gradient(135deg,#60a5fa 0%,#4f7df3 100%);border:none;border-radius:12px;width:100%;margin-top:2px;padding:12px 16px;font-size:14px;font-weight:600;transition:transform .15s,filter .15s,box-shadow .15s;box-shadow:0 14px 28px #3b82f63d}.auth-btn-primary:hover:not(:disabled){filter:brightness(1.04);transform:translateY(-1px)}.auth-btn-primary:disabled{opacity:.5;cursor:not-allowed}.auth-switch{text-align:center;color:var(--text-4);font-size:12px}.auth-switch-link{cursor:pointer;color:#3b82f6;background:0 0;border:none;padding:0;font-size:12px;text-decoration:underline}.auth-switch-link:hover{color:#60a5fa}.auth-forgot-link{cursor:pointer;color:var(--text-4);text-align:right;background:0 0;border:none;width:100%;margin:-6px 0 12px;padding:0;font-size:11.5px;text-decoration:underline;display:block}.auth-forgot-link:hover{color:#60a5fa}.sidebar-auth{border-top:1px solid var(--border);flex-direction:column;gap:6px;padding:10px 8px;display:flex}.sidebar-auth-row{align-items:center;gap:8px;display:flex}.sidebar-auth-row .sidebar-auth-signin,.sidebar-auth-row .sidebar-auth-signout{flex:1;width:auto;min-width:0}.sidebar-auth-settings{width:30px;color:var(--text-4);cursor:pointer;background:0 0;border:1px solid #2d3748;border-radius:6px;flex-shrink:0;justify-content:center;align-self:stretch;align-items:center;transition:background .15s,border-color .15s,color .15s;display:inline-flex}.sidebar-auth-settings:hover{background:var(--bg-surface);border-color:var(--border-strong);color:var(--text-1)}.sidebar-auth-email{align-items:center;gap:8px;padding:4px 6px;display:flex}.sidebar-auth-avatar{color:#fff;background:#3b82f6;border-radius:50%;flex-shrink:0;justify-content:center;align-items:center;width:24px;height:24px;font-size:11px;font-weight:700;display:flex}.sidebar-auth-email-text{color:var(--text-4);text-overflow:ellipsis;white-space:nowrap;flex:1;font-size:11px;overflow:hidden}.sync-status-dot{color:var(--sync-dot-text);flex-shrink:0;align-items:center;display:inline-flex}.sync-status-dot--syncing{color:var(--sync-dot-syncing-text);animation:1s ease-in-out infinite sync-status-pulse}.sync-status-dot--offline{color:var(--text-4)}.sync-status-dot--error{color:var(--sync-dot-error-text)}@keyframes sync-status-pulse{0%,to{opacity:1}50%{opacity:.35}}.sidebar-auth-signout{color:var(--text-4);cursor:pointer;background:0 0;border:1px solid #2d3748;border-radius:6px;align-items:center;gap:6px;width:100%;padding:6px 10px;font-size:12px;transition:color .15s,border-color .15s;display:flex}.sidebar-auth-signout:hover{color:var(--text-3);border-color:#4b5563}.sidebar-auth-signin{color:#60a5fa;cursor:pointer;background:0 0;border:1px solid #2563eb;border-radius:6px;align-items:center;gap:6px;width:100%;padding:7px 10px;font-size:12px;transition:background .15s,color .15s;display:flex}.sidebar-auth-signin:hover{color:#93c5fd;background:#3b82f614}.completion-nudge{background:#3b82f614;border:1px solid #3b82f640;border-radius:8px;align-items:center;gap:8px;margin-top:16px;padding:10px 14px;font-size:13px;display:flex}.completion-nudge-icon{flex-shrink:0;font-size:16px}.completion-nudge-text{color:var(--text-3);text-align:left;flex:1}.completion-dismiss-btn{cursor:pointer;color:#4b5563;background:0 0;border:none;border-radius:4px;padding:4px;font-size:14px;line-height:1;transition:color .15s;position:absolute;top:10px;right:12px}.completion-dismiss-btn:hover{color:var(--text-3)}.completion-card{position:relative}.pw-nudge-banner{background:#3b82f612;border:1px solid #3b82f633;border-radius:10px;align-items:center;gap:10px;margin-bottom:4px;padding:12px 16px;display:flex}.pw-nudge-icon{flex-shrink:0;font-size:18px}.pw-nudge-text{color:var(--text-3);flex:1;font-size:13px}.cmdk-overlay{z-index:1000;-webkit-backdrop-filter:blur(2px);backdrop-filter:blur(2px);background:#02061799;justify-content:center;align-items:flex-start;padding-top:12vh;display:flex;position:fixed;inset:0}.cmdk-panel{background:var(--bg-panel);border:1px solid var(--border);border-radius:12px;flex-direction:column;width:min(560px,92vw);max-height:64vh;display:flex;overflow:hidden;box-shadow:0 20px 60px #00000080}.cmdk-input-wrap{border-bottom:1px solid var(--border);align-items:center;gap:8px;padding:12px 14px;display:flex}.cmdk-input{color:var(--text-1);background:0 0;border:none;outline:none;flex:1;font-family:inherit;font-size:15px}.cmdk-input::placeholder{color:var(--text-muted)}.cmdk-esc{color:var(--text-4);background:var(--bg-deep);border:1px solid var(--border);border-radius:4px;padding:2px 6px;font-size:11px}.cmdk-results{margin:0;padding:6px;list-style:none;overflow-y:auto}.cmdk-item{width:100%;color:var(--text-1);text-align:left;cursor:pointer;background:0 0;border:none;border-radius:8px;align-items:center;gap:10px;padding:9px 10px;font-size:13px;display:flex}.cmdk-item--active{background:var(--bg-surface)}.cmdk-kind{letter-spacing:.5px;text-transform:uppercase;text-align:center;border:1px solid #0000;border-radius:5px;flex-shrink:0;width:58px;padding:3px 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0;border:none;border-radius:6px;justify-content:center;align-items:center;padding:2px;display:inline-flex}.shk-close:hover{color:var(--text-2);background:var(--bg-surface)}.shk-section{padding:10px 16px 14px}.shk-section-label{letter-spacing:1px;text-transform:uppercase;color:var(--text-muted);margin-bottom:8px;font-size:11px;font-weight:700}.shk-row{justify-content:space-between;align-items:center;gap:12px;padding:5px 0;display:flex}.shk-row-label{color:var(--text-1);font-size:13px}.shk-row-keys{flex-shrink:0;gap:4px;display:inline-flex}.shk-kbd{color:var(--text-3);background:var(--bg-deep);border:1px solid var(--border);text-align:center;border-bottom-width:2px;border-radius:5px;min-width:18px;padding:2px 7px;font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:11px}.pane-tab{position:relative}.pane-tab-dot{vertical-align:middle;background:#fbbf24;border-radius:50%;width:6px;height:6px;margin-left:6px;display:inline-block}.notes-pane{flex-direction:column;height:100%;display:flex}.notes-textarea{resize:none;background:var(--notes-textarea-bg);width:100%;color:var(--text-2);border:none;outline:none;flex:1;padding:14px 16px;font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:13px;line-height:1.6}.notes-textarea::placeholder{color:var(--text-muted)}.zen-exit{z-index:900;color:var(--text-1);background:var(--bg-surface);border:1px solid var(--border-strong);cursor:pointer;opacity:.85;border-radius:999px;align-items:center;gap:7px;padding:6px 12px;font-family:inherit;font-size:12px;font-weight:600;transition:opacity .15s,background .15s;display:inline-flex;position:fixed;bottom:20px;right:20px;box-shadow:0 6px 20px #0006}.zen-exit:hover{opacity:1;background:var(--bg-hover)}.zen-exit kbd{color:var(--text-3);background:var(--bg-deep);border:1px solid var(--border-strong);border-radius:4px;padding:1px 5px;font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:11px}.pw-daily{align-items:center;gap:10px;margin-left:auto;display:inline-flex}.pw-daily-ring{flex-shrink:0}.pw-daily-text{flex-direction:column;line-height:1.1;display:flex}.pw-daily-count{color:var(--text-1);font-variant-numeric:tabular-nums;font-size:16px;font-weight:800}.pw-daily-label{letter-spacing:.5px;text-transform:uppercase;color:var(--text-4);font-size:11px;font-weight:600}.editor-format-btn{border:1px solid var(--editor-btn-border);height:20px;color:var(--editor-btn-text);cursor:pointer;background:0 0;border-radius:4px;align-items:center;margin-right:4px;padding:0 9px;font-family:inherit;font-size:11px;font-weight:600;transition:background .15s,border-color .15s,color 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#0000004d}.consent-banner-text{min-width:240px;color:var(--text-2);flex:1;margin:0;font-size:13px}.consent-banner-actions{flex-shrink:0;gap:8px;display:flex}.practice-tag-row{gap:6px;margin-top:8px;display:flex}.practice-tag-row .practice-tag-select{flex:1;min-width:0;margin-top:0}.practice-shuffle-btn{background:var(--practice-shuffle-bg);border:1px solid var(--practice-shuffle-border);color:#64748b;cursor:pointer;border-radius:6px;flex-shrink:0;justify-content:center;align-items:center;width:28px;transition:color .15s,border-color .15s;display:inline-flex}.practice-shuffle-btn:hover:not(:disabled){color:var(--practice-shuffle-hover-text);border-color:#3b82f6}.practice-shuffle-btn:disabled{opacity:.4;cursor:not-allowed}.practice-tag-select{appearance:none;width:100%;color:var(--practice-tag-select-text);background:var(--practice-tag-select-bg);border:1px solid var(--practice-tag-select-border);cursor:pointer;border-radius:7px;margin-top:8px;padding:5px 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.15s}.mock-banner-btn:hover{color:var(--mock-banner-btn-hover-text);border-color:var(--mock-banner-btn-hover-border)}.mock-banner-btn--next{color:var(--mock-banner-btn-next-text);border-color:var(--mock-banner-btn-next-border)}.mock-banner-btn--next:hover{color:#99f6e4;border-color:#14b8a6}.mock-summary-list{flex-direction:column;gap:8px;margin:14px 0;padding:0;list-style:none;display:flex}.mock-summary-row{align-items:center;gap:10px;font-size:13.5px;display:flex}.mock-summary-mark{background:var(--mock-summary-mark-bg);width:20px;height:20px;color:var(--mock-summary-mark-text);border-radius:50%;flex-shrink:0;justify-content:center;align-items:center;font-size:12px;font-weight:800;display:inline-flex}.mock-summary-mark--solved{background:var(--mock-summary-mark-solved-bg);color:var(--mock-summary-mark-solved-text)}.mock-summary-name{text-align:left;color:var(--mock-summary-name-text);flex:1}.mock-summary-time{font-variant-numeric:tabular-nums;color:#64748b;font-size:12.5px}.mock-summary-total{color:#94a3b8;text-align:center;margin:0 0 6px;font-size:13px;font-weight:600}.activity-day{background:var(--activity-day-bg);max-width:860px;margin:0 auto;padding:32px 24px 64px;font-family:inherit}.activity-day-header{align-items:center;gap:16px;margin-bottom:28px;display:flex}.activity-day-title{color:var(--activity-day-title-text);margin:0;font-size:20px;font-weight:700}.activity-stats{grid-template-columns:repeat(3,1fr);gap:16px;margin-bottom:28px;display:grid}.activity-stat-card{background:var(--activity-stat-card-bg);border:1px solid var(--activity-stat-card-border);border-radius:12px;flex-direction:column;gap:6px;padding:20px 20px 16px;display:flex}.activity-stat-card--accepted{border-left-color:var(--activity-stat-accepted-border-left)}.activity-stat-card--wrong{border-left-color:var(--activity-stat-wrong-border-left)}.activity-stat-num{color:var(--activity-stat-num-text);font-size:36px;font-weight:800;line-height:1}.activity-stat-card--accepted .activity-stat-num{color:var(--activity-stat-accepted-num-text)}.activity-stat-card--wrong .activity-stat-num{color:var(--activity-stat-wrong-num-text)}.activity-stat-lbl{letter-spacing:.8px;text-transform:uppercase;color:#64748b;font-size:11px;font-weight:700}.activity-stat-note{color:#475569;margin-top:2px;font-size:11px}.activity-table{border-collapse:collapse;width:100%;font-size:14px}.activity-table th{text-align:left;color:var(--activity-th-text);border-bottom:1px solid var(--activity-th-border);padding:10px 14px;font-size:12px;font-weight:600}.activity-row{cursor:pointer;transition:background .12s}.activity-row:hover{background:var(--activity-row-hover-bg)}.activity-row td{border-bottom:1px solid var(--activity-td-border);color:var(--activity-td-text);vertical-align:middle;padding:14px}.activity-problem{color:var(--activity-problem-text);font-weight:500}.activity-status{font-weight:600}.activity-status--accepted{color:var(--activity-status-accepted-text)}.activity-time{color:#64748b;font-variant-numeric:tabular-nums}.activity-empty{text-align:center;color:#475569;padding:48px 0;font-size:14px}.activity-empty-text{margin:0 0 16px}.hm-cell--l0{background:var(--hm-l0-bg)}.hints-actions{flex-wrap:wrap;gap:8px;padding:0 16px 14px;display:flex}.concept-topic-title{color:var(--text-1);margin:0;font-size:17px;font-weight:700;line-height:1.3}.settings-row-text{flex-direction:column;flex:1;gap:2px;display:flex}