:root{--color-primary: #4f6ef7;--color-primary-dark: #3a55d4;--color-danger: #e53e3e;--color-danger-dark: #c53030;--color-success: #38a169;--color-text: #1a202c;--color-text-muted: #718096;--color-border: #e2e8f0;--color-bg: #f7fafc;--color-surface: #ffffff;--color-header-bg: #ffffff;--radius: 8px;--shadow: 0 1px 3px rgba(0, 0, 0, .1), 0 1px 2px rgba(0, 0, 0, .06);--shadow-md: 0 4px 6px rgba(0, 0, 0, .07), 0 2px 4px rgba(0, 0, 0, .06)}*,*:before,*:after{box-sizing:border-box;margin:0;padding:0}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif;background:var(--color-bg);color:var(--color-text);line-height:1.5;min-height:100vh}.app-layout{display:flex;flex-direction:column;min-height:100vh}.app-header{position:sticky;top:0;z-index:10;display:flex;align-items:center;gap:12px;padding:0 20px;height:60px;background:var(--color-header-bg);border-bottom:1px solid var(--color-border);box-shadow:var(--shadow)}.app-brand{font-size:1.25rem;font-weight:700;color:var(--color-primary);flex:1}.group-title{font-size:1rem;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;max-width:200px}.header-actions{display:flex;align-items:center;gap:8px;margin-left:auto}.user-name{font-size:.875rem;color:var(--color-text-muted);max-width:120px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.main-content{flex:1;max-width:720px;width:100%;margin:0 auto;padding:24px 16px}.section-header{display:flex;align-items:center;justify-content:space-between;margin-bottom:16px}.section-header h2{font-size:1.1rem;font-weight:600}.btn{display:inline-flex;align-items:center;gap:6px;padding:8px 16px;border:none;border-radius:var(--radius);font-size:.875rem;font-weight:500;cursor:pointer;transition:background .15s,opacity .15s;white-space:nowrap}.btn:disabled{opacity:.6;cursor:not-allowed}.btn-primary{background:var(--color-primary);color:#fff}.btn-primary:hover:not(:disabled){background:var(--color-primary-dark)}.btn-secondary{background:var(--color-border);color:var(--color-text)}.btn-secondary:hover:not(:disabled){background:#cbd5e0}.btn-ghost{background:transparent;color:var(--color-text-muted)}.btn-ghost:hover:not(:disabled){background:var(--color-border)}.btn-danger{background:var(--color-danger);color:#fff}.btn-danger:hover:not(:disabled){background:var(--color-danger-dark)}.btn-sm{padding:4px 10px;font-size:.75rem}.btn-close{background:none;border:none;font-size:1.5rem;cursor:pointer;color:var(--color-text-muted);line-height:1;padding:2px 6px}.btn-close:hover{color:var(--color-text)}.input{width:100%;padding:10px 12px;border:1px solid var(--color-border);border-radius:var(--radius);font-size:.9375rem;background:var(--color-surface);color:var(--color-text);transition:border-color .15s}.input:focus{outline:none;border-color:var(--color-primary)}.form-field{display:flex;flex-direction:column;gap:6px;margin-bottom:16px}.form-field label{font-size:.875rem;font-weight:500;color:var(--color-text)}.checkbox-group{display:flex;flex-direction:column;gap:8px}.checkbox-label{display:flex;align-items:center;gap:8px;font-size:.9rem;cursor:pointer}.modal-overlay{position:fixed;top:0;right:0;bottom:0;left:0;background:#00000073;display:flex;align-items:center;justify-content:center;z-index:100;padding:16px}.modal{background:var(--color-surface);border-radius:12px;box-shadow:var(--shadow-md);width:100%;max-width:440px;max-height:90vh;overflow:hidden;display:flex;flex-direction:column}.modal-header{display:flex;align-items:center;justify-content:space-between;padding:16px 20px;border-bottom:1px solid var(--color-border)}.modal-header h3{font-size:1rem;font-weight:600}.modal-body{padding:20px;overflow-y:auto}.modal-footer{display:flex;justify-content:flex-end;gap:8px;padding-top:8px}.group-list{list-style:none;display:flex;flex-direction:column;gap:10px}.group-item{display:flex;align-items:center;justify-content:space-between;padding:14px 16px;background:var(--color-surface);border:1px solid var(--color-border);border-radius:var(--radius);box-shadow:var(--shadow)}.group-item-info{display:flex;flex-direction:column;gap:2px}.group-name{font-weight:600}.group-members{font-size:.8rem;color:var(--color-text-muted)}.group-item-actions{display:flex;gap:8px}.member-chips{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:4px}.member-chip{display:flex;align-items:center;gap:6px;padding:4px 10px 4px 4px;background:var(--color-surface);border:1px solid var(--color-border);border-radius:20px;box-shadow:var(--shadow)}.member-chip-avatar{width:24px;height:24px;border-radius:50%;background:var(--color-primary);color:#fff;font-size:.7rem;font-weight:700;display:flex;align-items:center;justify-content:center;flex-shrink:0}.member-chip-name{font-size:.85rem;color:var(--color-text)}.member-chip-remove{width:18px;height:18px;border-radius:50%;border:none;background:transparent;color:var(--color-text-muted);font-size:1rem;line-height:1;cursor:pointer;display:flex;align-items:center;justify-content:center;padding:0;flex-shrink:0}.member-chip-remove:hover{background:var(--color-danger);color:#fff}.expense-filters{display:flex;gap:8px;margin-bottom:12px}.input-sm{padding:6px 10px;font-size:.875rem;height:auto}#expense-search{flex:1}#expense-filter-payer{flex-shrink:0;width:auto}.expense-list{list-style:none;display:flex;flex-direction:column;gap:10px}.expense-item{display:flex;align-items:center;justify-content:space-between;padding:12px 16px;background:var(--color-surface);border:1px solid var(--color-border);border-radius:var(--radius);box-shadow:var(--shadow);gap:12px}.expense-item-settlement{background:#ebf8ff;border-color:#bee3f8}.expense-info{display:flex;flex-direction:column;gap:2px;flex:1;min-width:0}.expense-desc{font-weight:500;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.expense-meta{font-size:.8rem;color:var(--color-text-muted)}.expense-right{display:flex;align-items:center;gap:10px;flex-shrink:0}.expense-amount{font-weight:700;font-size:1rem;color:var(--color-primary)}.expense-avatar{width:36px;height:36px;border-radius:50%;color:#fff;font-size:.9rem;font-weight:700;display:flex;align-items:center;justify-content:center;flex-shrink:0}.tab-bar{display:flex;border-bottom:2px solid var(--color-border);margin-bottom:12px}.tab-btn{padding:8px 20px;background:none;border:none;border-bottom:2px solid transparent;margin-bottom:-2px;font-size:.9rem;font-weight:500;color:var(--color-text-muted);cursor:pointer}.tab-btn.active{color:var(--color-primary);border-bottom-color:var(--color-primary)}.log-list{list-style:none;display:flex;flex-direction:column;gap:10px}.log-item{display:flex;align-items:flex-start;gap:12px;padding:12px 16px;background:var(--color-surface);border:1px solid var(--color-border);border-radius:var(--radius);box-shadow:var(--shadow)}.log-info{display:flex;flex-direction:column;gap:2px;flex:1;min-width:0}.log-desc{font-size:.9rem;color:var(--color-text)}.log-amount{font-weight:600;color:var(--color-primary)}.log-meta{font-size:.78rem;color:var(--color-text-muted)}.log-action{font-weight:600;border-radius:4px;padding:1px 6px;font-size:.75rem;text-transform:uppercase;letter-spacing:.03em}.log-action-added{background:#c6f6d5;color:#276749}.log-action-edited{background:#bee3f8;color:#2a69ac}.log-action-deleted{background:#fed7d7;color:#9b2c2c}.settlement-group-header{display:flex;align-items:center;gap:6px;margin-bottom:16px}.settlement-group-name{font-size:1.2rem;font-weight:700;color:var(--color-primary)}.settlement-section{background:var(--color-surface);border:1px solid var(--color-border);border-radius:var(--radius);padding:16px;margin-bottom:24px;box-shadow:var(--shadow)}.section-title{font-size:.875rem;font-weight:600;color:var(--color-text-muted);text-transform:uppercase;letter-spacing:.05em;margin-bottom:10px;margin-top:16px}.section-title:first-child{margin-top:0}.balance-list,.settlement-list{list-style:none;display:flex;flex-direction:column;gap:6px}.balance-item{display:flex;justify-content:space-between;align-items:center;font-size:.9rem}.balance-amount.positive{color:var(--color-success);font-weight:600}.balance-amount.negative{color:var(--color-danger);font-weight:600}.balance-amount.zero{color:var(--color-text-muted)}.settlement-item{display:flex;align-items:center;justify-content:space-between;gap:8px;font-size:.9rem}.settlement-info{display:flex;align-items:center;gap:8px;flex:1;min-width:0}.btn-confirm{background:#ebf8f0;color:var(--color-success);border:1px solid #9ae6b4;flex-shrink:0}.btn-confirm:hover:not(:disabled){background:#c6f6d5}.settlement-arrow{color:var(--color-text-muted)}.settlement-to{font-weight:600}.settlement-amount{margin-left:auto;font-weight:700;color:var(--color-primary)}.empty-state-text{font-size:.9rem;color:var(--color-text-muted);text-align:center;padding:8px 0}.login-page{display:flex;align-items:center;justify-content:center;min-height:100vh;padding:16px}.login-card{background:var(--color-surface);border:1px solid var(--color-border);border-radius:16px;box-shadow:var(--shadow-md);padding:40px 32px;text-align:center;width:100%;max-width:360px;display:flex;flex-direction:column;align-items:center;gap:12px}.login-logo{margin-bottom:4px}.login-title{font-size:1.75rem;font-weight:800;color:var(--color-primary)}.login-subtitle{color:var(--color-text-muted);margin-bottom:8px}.auth-form{display:flex;flex-direction:column;gap:10px;width:100%;margin-bottom:4px}.btn-full{width:100%;justify-content:center;padding:12px;font-size:.9375rem}.auth-success{font-size:.85rem;color:var(--color-success);text-align:left;margin-bottom:8px}.auth-error{font-size:.85rem;color:var(--color-danger);text-align:left}.auth-toggle{font-size:.875rem;color:var(--color-text-muted)}.btn-link{background:none;border:none;color:var(--color-primary);cursor:pointer;font-size:inherit;padding:0;text-decoration:underline}.invite-success{font-size:.85rem;color:var(--color-success)}.contact-history{margin-bottom:4px}.contact-history-label{font-size:.75rem;font-weight:600;text-transform:uppercase;letter-spacing:.05em;color:var(--color-text-muted);margin-bottom:8px}.contact-list{list-style:none;display:flex;flex-direction:column;gap:6px;max-height:200px;overflow-y:auto;margin-bottom:4px}.contact-item{display:flex;align-items:center;gap:10px;padding:6px 8px;border-radius:var(--radius);background:var(--color-bg)}.contact-avatar{width:32px;height:32px;border-radius:50%;background:var(--color-primary);color:#fff;font-size:.875rem;font-weight:700;display:flex;align-items:center;justify-content:center;flex-shrink:0}.contact-name{flex:1;font-size:.9rem;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.contact-divider{font-size:.75rem;color:var(--color-text-muted);text-align:center;margin:12px 0 8px;position:relative}.contact-divider:before,.contact-divider:after{content:"";position:absolute;top:50%;width:30%;height:1px;background:var(--color-border)}.contact-divider:before{left:0}.contact-divider:after{right:0}.empty-state{text-align:center;padding:40px 16px;color:var(--color-text-muted)}.spinner{width:32px;height:32px;border:3px solid var(--color-border);border-top-color:var(--color-primary);border-radius:50%;animation:spin .7s linear infinite}.spinner-center{margin:80px auto}@keyframes spin{to{transform:rotate(360deg)}}.error-page{display:flex;align-items:center;justify-content:center;min-height:60vh;color:var(--color-text-muted);font-size:1.1rem}.back-btn{flex-shrink:0}.group-title-row{display:flex;align-items:center;gap:4px;flex:1;min-width:0}.btn-icon{background:none;border:none;cursor:pointer;font-size:1rem;color:var(--color-text-muted);padding:2px 4px;flex-shrink:0;line-height:1}.btn-icon:hover{color:var(--color-text)}.profile-card{background:var(--color-surface);border:1px solid var(--color-border);border-radius:var(--radius);box-shadow:var(--shadow);padding:32px 24px;display:flex;flex-direction:column;align-items:center;gap:8px}.profile-avatar{width:64px;height:64px;border-radius:50%;background:var(--color-primary);color:#fff;font-size:1.75rem;font-weight:700;display:flex;align-items:center;justify-content:center}.profile-name{font-size:1.2rem;font-weight:700;margin-bottom:8px}.profile-fields{width:100%;display:flex;flex-direction:column;gap:20px;margin-top:12px}.profile-field{display:flex;flex-direction:column;gap:4px}.profile-label{font-size:.75rem;font-weight:600;text-transform:uppercase;letter-spacing:.05em;color:var(--color-text-muted)}.profile-value{font-size:.9375rem;color:var(--color-text)}.profile-id{font-family:monospace;font-size:.8rem;word-break:break-all;color:var(--color-text-muted)}.profile-id-row{display:flex;align-items:center;gap:8px}.profile-hint{font-size:.8rem;color:var(--color-text-muted);margin-top:2px}.color-swatches{display:flex;gap:8px;flex-wrap:wrap;margin-top:4px}.color-swatch{width:32px;height:32px;border-radius:50%;border:3px solid transparent;cursor:pointer;outline:none;transition:transform .1s,border-color .1s}.color-swatch:hover{transform:scale(1.12)}.color-swatch.active{border-color:var(--color-text)}.username-form{display:flex;flex-direction:column;gap:8px}.username-actions{display:flex;justify-content:flex-end}