:root{--color-background: #f8fafc;--color-surface: #ffffff;--color-surfaceHover: #f1f5f9;--color-primary: #4f46e5;--color-primaryHover: #4338ca;--color-secondary: #64748b;--color-text: #1e293b;--color-textMuted: #64748b;--color-textInverse: #ffffff;--color-border: #e2e8f0;--color-success: #22c55e;--color-danger: #ef4444;--color-dangerHover: #dc2626;--color-warning: #f59e0b;--color-shadow: rgba(0, 0, 0, .1);--font-family: system-ui, -apple-system, sans-serif}*,*:before,*:after{box-sizing:border-box;margin:0;padding:0}html{font-size:16px;-webkit-text-size-adjust:100%}body{font-family:var(--font-family);background:var(--color-background);color:var(--color-text);line-height:1.5;min-height:100vh}.app{min-height:100vh}.btn{display:inline-flex;align-items:center;justify-content:center;gap:.5rem;padding:.625rem 1.25rem;font-size:.9375rem;font-weight:500;font-family:inherit;border:none;border-radius:.5rem;cursor:pointer;transition:all .15s ease;white-space:nowrap}.btn:disabled{opacity:.6;cursor:not-allowed}.btn-primary{background:var(--color-primary);color:var(--color-textInverse)}.btn-primary:hover:not(:disabled){background:var(--color-primaryHover)}.btn-secondary{background:var(--color-surface);color:var(--color-text);border:1px solid var(--color-border)}.btn-secondary:hover:not(:disabled){background:var(--color-surfaceHover)}.btn-danger{background:var(--color-danger);color:var(--color-textInverse)}.btn-danger:hover:not(:disabled){background:var(--color-dangerHover)}.btn-small{padding:.375rem .75rem;font-size:.8125rem}.btn-large{padding:.875rem 2rem;font-size:1.125rem}.input{width:100%;padding:.625rem .875rem;font-size:1rem;font-family:inherit;color:var(--color-text);background:var(--color-surface);border:1px solid var(--color-border);border-radius:.5rem;transition:border-color .15s ease,box-shadow .15s ease}.input:focus{outline:none;border-color:var(--color-primary);box-shadow:0 0 0 3px var(--color-shadow)}.input::placeholder{color:var(--color-textMuted)}.input-small{width:6rem;text-align:right}.input-amount{font-size:1.25rem;text-align:right}select.input{cursor:pointer}.landing{min-height:100vh;display:flex;align-items:center;justify-content:center;padding:2rem}.landing-content{max-width:28rem;text-align:center}.landing-header{margin-bottom:2.5rem}.landing-title{font-size:3rem;font-weight:800;color:var(--color-primary);margin-bottom:.75rem}.landing-subtitle{font-size:1.25rem;color:var(--color-textMuted)}.landing-features{display:flex;flex-direction:column;gap:1rem;margin-bottom:2.5rem;text-align:left}.feature{display:flex;align-items:center;gap:1rem;padding:1rem;background:var(--color-surface);border-radius:.75rem;box-shadow:0 1px 3px var(--color-shadow)}.feature-icon{display:flex;align-items:center;justify-content:center;width:2rem;height:2rem;background:var(--color-primary);color:var(--color-textInverse);border-radius:50%;font-weight:600;font-size:.875rem}.landing-footer{margin-top:3rem}.error-message{color:var(--color-danger);font-size:.875rem;margin-top:.75rem}.loading-container,.error-container{display:flex;flex-direction:column;align-items:center;justify-content:center;min-height:100vh;padding:2rem;text-align:center;gap:1rem}.loading-spinner{width:3rem;height:3rem;border:3px solid var(--color-border);border-top-color:var(--color-primary);border-radius:50%;animation:spin .8s linear infinite}@keyframes spin{to{transform:rotate(360deg)}}.empty-message{color:var(--color-textMuted);font-style:italic;padding:1.5rem;text-align:center}.empty-message.all-settled{font-style:normal;font-weight:500;color:var(--color-success)}.group-view{max-width:48rem;margin:0 auto;padding:1rem 1rem 6rem}.group-header{display:flex;flex-direction:column;gap:1rem;margin-bottom:1.5rem;padding:1rem;background:var(--color-surface);border-radius:.75rem;box-shadow:0 1px 3px var(--color-shadow)}.group-title-row{display:flex;align-items:center}.group-name{font-size:1.75rem;font-weight:700;cursor:pointer;display:flex;align-items:center;gap:.5rem}.group-name:hover .edit-icon{opacity:1}.edit-icon{font-size:1rem;opacity:.3;transition:opacity .15s}.group-name-input{font-size:1.75rem;font-weight:700}.group-actions{display:flex;flex-wrap:wrap;gap:.5rem}.section{margin-bottom:1rem;padding:.75rem;background:var(--color-surface);border-radius:.5rem;box-shadow:0 1px 3px var(--color-shadow)}.section-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:.75rem}.section-header h2{font-size:1rem;font-weight:600}.add-member-form{display:flex;gap:.5rem;margin-bottom:.75rem}.add-member-form .input{flex:1}.member-items{list-style:none}.member-item{display:flex;align-items:center;justify-content:space-between;padding:.5rem .25rem;border-bottom:1px solid var(--color-border)}.member-item:last-child{border-bottom:none}.member-info{display:flex;align-items:center;gap:1rem}.member-name{font-weight:500}.member-balance{font-size:.875rem;font-weight:600}.member-balance.positive{color:var(--color-success)}.member-balance.negative{color:var(--color-danger)}.balance-summary h2{font-size:1rem;font-weight:600;margin-bottom:.75rem}.debt-list{list-style:none}.debt-item{display:flex;align-items:center;gap:.5rem;padding:.5rem .25rem;border-bottom:1px solid var(--color-border);flex-wrap:wrap}.debt-item:last-child{border-bottom:none}.btn-square-up{padding:.25rem .5rem;font-size:.75rem;margin-left:.5rem}.debt-from{font-weight:600;color:var(--color-danger)}.debt-arrow{color:var(--color-textMuted)}.debt-to{font-weight:600;color:var(--color-success)}.debt-amount{margin-left:auto;font-weight:600;color:var(--color-text)}.transaction-list{list-style:none}.transaction-item{padding:.625rem .25rem;border-bottom:1px solid var(--color-border)}.transaction-item:last-child{border-bottom:none}.transaction-main{display:flex;justify-content:space-between;align-items:flex-start;gap:.75rem;margin-bottom:.375rem}.transaction-info{display:flex;flex-direction:column;gap:.25rem}.transaction-description{font-weight:500}.transaction-meta{font-size:.8125rem;color:var(--color-textMuted)}.transaction-amount{font-size:1.125rem;font-weight:600;white-space:nowrap}.transaction-splits{display:flex;flex-wrap:wrap;gap:.375rem;margin-bottom:.5rem}.split-chip{font-size:.75rem;padding:.25rem .5rem;background:var(--color-surfaceHover);border-radius:1rem;color:var(--color-textMuted)}.transaction-actions{display:flex;gap:.5rem}.modal-overlay{position:fixed;top:0;right:0;bottom:0;left:0;background:#00000080;display:flex;align-items:center;justify-content:center;padding:1rem;z-index:100}.modal{width:100%;max-width:28rem;max-height:90vh;overflow-y:auto;background:var(--color-surface);border-radius:.75rem;box-shadow:0 10px 40px var(--color-shadow)}.modal-confirm{max-width:24rem}.confirm-message{color:var(--color-text);line-height:1.5;margin-bottom:1.5rem}.toast{position:fixed;bottom:5rem;left:50%;transform:translate(-50%);background:var(--color-text);color:var(--color-background);padding:.75rem 1.5rem;border-radius:.5rem;font-size:.875rem;font-weight:500;box-shadow:0 4px 12px var(--color-shadow);z-index:200;animation:toast-in .2s ease-out}@keyframes toast-in{0%{opacity:0;transform:translate(-50%) translateY(1rem)}to{opacity:1;transform:translate(-50%) translateY(0)}}.modal-header{display:flex;justify-content:space-between;align-items:center;padding:1rem 1.25rem;border-bottom:1px solid var(--color-border)}.modal-header h2{font-size:1.25rem;font-weight:600}.modal-close{background:none;border:none;font-size:1.5rem;color:var(--color-textMuted);cursor:pointer;padding:.25rem;line-height:1}.modal-close:hover{color:var(--color-text)}.modal-body{padding:1.25rem}.form-group{margin-bottom:1.25rem}.form-group label{display:block;font-size:.875rem;font-weight:500;margin-bottom:.5rem;color:var(--color-text)}.participant-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(8rem,1fr));gap:.5rem}.participant-toggle{padding:.5rem .75rem;font-size:.875rem;font-family:inherit;font-weight:500;text-align:center;background:var(--color-surface);color:var(--color-textMuted);border:2px solid var(--color-border);border-radius:.375rem;cursor:pointer;transition:all .15s ease}.participant-toggle:hover{border-color:var(--color-primary);color:var(--color-text)}.participant-toggle.active{background:var(--color-primary);color:var(--color-textInverse);border-color:var(--color-primary)}.split-toggle{display:flex;gap:.5rem}.split-btn{flex:1;padding:.5rem;font-size:.875rem;font-family:inherit;background:var(--color-surfaceHover);color:var(--color-textMuted);border:1px solid var(--color-border);border-radius:.375rem;cursor:pointer;transition:all .15s}.split-btn.active{background:var(--color-primary);color:var(--color-textInverse);border-color:var(--color-primary)}.split-preview{text-align:center;padding:1rem;background:var(--color-surfaceHover);border-radius:.5rem}.split-preview-label{font-size:.875rem;color:var(--color-textMuted);margin-bottom:.25rem}.split-preview-amount{font-size:1.5rem;font-weight:600}.custom-splits{display:flex;flex-direction:column;gap:.75rem}.custom-split-row{display:flex;justify-content:space-between;align-items:center}.custom-split-name{font-weight:500}.split-diff{text-align:right;font-size:.875rem;color:var(--color-warning)}.split-diff.error{color:var(--color-danger)}.modal-actions{display:flex;gap:.75rem;justify-content:flex-end;margin-top:1.5rem}.fab{position:fixed;bottom:1.5rem;right:1.5rem;width:3.5rem;height:3.5rem;border-radius:50%;background:var(--color-primary);color:var(--color-textInverse);font-size:2rem;font-weight:300;line-height:1;border:none;box-shadow:0 4px 12px var(--color-shadow);cursor:pointer;transition:all .15s;z-index:50}.fab:hover:not(:disabled){background:var(--color-primaryHover);transform:scale(1.05)}.fab:disabled{opacity:.5;cursor:not-allowed}.theme-picker{position:relative}.theme-picker-overlay{position:fixed;top:0;right:0;bottom:0;left:0;z-index:99}.theme-picker-menu{position:absolute;top:100%;right:0;margin-top:.5rem;background:#fff;border:1px solid #e2e8f0;border-radius:.5rem;box-shadow:0 4px 12px #00000026;min-width:12rem;z-index:100;overflow:hidden}.theme-option{display:flex;align-items:center;gap:.75rem;width:100%;padding:.75rem 1rem;font-size:.875rem;font-family:system-ui,-apple-system,sans-serif;text-align:left;text-transform:none;letter-spacing:normal;background:none;border:none;color:#1e293b;cursor:pointer;transition:background .15s}.theme-option:hover,.theme-option.active{background:#f1f5f9}.theme-preview{width:1.5rem;height:1.5rem;border-radius:50%;background:linear-gradient(135deg,var(--preview-bg) 50%,var(--preview-primary) 50%);border:2px solid var(--preview-text)}.theme-name{flex:1;color:#1e293b}.theme-check{color:#22c55e;font-weight:600}.theme-lovey .landing-title:after,.theme-lovey .group-name:after{content:" 💕"}.theme-hotdog{font-weight:600}.theme-hotdog .btn{border:2px solid #000;box-shadow:2px 2px #000}.theme-terminal{text-transform:uppercase;letter-spacing:.05em}.theme-terminal .landing-title:before{content:"> "}.theme-cyberpunk .btn-primary{box-shadow:0 0 20px var(--color-primary)}@media (max-width: 640px){.landing-title{font-size:2.25rem}.group-header{padding:.75rem}.group-name{font-size:1.5rem}.section{padding:.75rem}.transaction-main{flex-direction:column;gap:.5rem}.transaction-amount{font-size:1rem}.modal{max-height:100vh;border-radius:0}.modal-overlay{padding:0;align-items:flex-end}.fab{bottom:1rem;right:1rem}.add-member-form{flex-direction:column}.debt-item{flex-direction:row;flex-wrap:wrap;gap:.25rem .5rem}.debt-amount{margin-left:auto}.btn-square-up{margin-left:0;flex-basis:100%;margin-top:.25rem}}