:root{--color-violet-50: #eeecff;--color-violet-100: #d6d1ff;--color-violet-200: #bbb3ff;--color-violet-300: #9f94ff;--color-violet-400: #8b7dff;--color-violet-500: #7d6fff;--color-violet-600: #6c5cff;--color-violet-700: #5b4edb;--color-violet-800: #4a3fb8;--color-cyan-50: #e0f7fb;--color-cyan-100: #b3ebf7;--color-cyan-200: #80dff2;--color-cyan-300: #4dd3ed;--color-cyan-400: #4cc9f0;--color-cyan-500: #00b4d8;--color-cyan-600: #0096b6;--color-cyan-700: #007a94;--color-green-50: #e6f7f0;--color-green-100: #bfead6;--color-green-200: #95deb9;--color-green-300: #68d29b;--color-green-400: #2dc98a;--color-green-500: #0a9d63;--color-green-600: #078b56;--color-green-700: #05643e;--color-coral-50: #fdecea;--color-coral-100: #f9cbc4;--color-coral-200: #f5a79d;--color-coral-300: #f18376;--color-coral-400: #ff6b57;--color-coral-500: #e0533d;--color-coral-600: #c94531;--color-coral-700: #9f2e20;--color-navy-900: #0a0e27;--color-navy-800: #10163a;--color-navy-700: #161d4d;--color-navy-600: #1d2661;--color-navy-500: #253060;--color-white: #ffffff;--color-neutral-50: #f9fafb;--color-neutral-100: #f3f4f6;--color-neutral-200: #e5e7eb;--color-neutral-300: #d1d5db;--color-neutral-400: #9ca3af;--color-neutral-500: #6b7280;--color-neutral-600: #4b5563;--color-neutral-700: #374151;--color-neutral-800: #1f2937;--color-neutral-900: #111827;--color-text: var(--color-neutral-900);--color-text-muted: var(--color-neutral-600);--color-background: var(--color-white);--color-surface: var(--color-violet-50);--color-border: var(--color-neutral-200);--color-primary: var(--color-violet-600);--color-primary-hover: var(--color-violet-700);--color-primary-text: var(--color-white);--color-secondary: var(--color-cyan-50);--color-secondary-hover: var(--color-cyan-100);--color-secondary-text: var(--color-cyan-700);--color-positive: var(--color-green-500);--color-positive-bg: var(--color-green-50);--color-positive-text: var(--color-green-700);--color-owes: var(--color-coral-500);--color-owes-bg: var(--color-coral-50);--color-owes-text: var(--color-coral-700);--color-error: var(--color-coral-600);--font-display: "Fraunces", "Instrument Serif", Georgia, "Times New Roman", serif;--font-sans: "Inter", "SF Pro Display", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", "Noto Sans Arabic", sans-serif;--font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;--font-cjk: "Noto Sans SC", "Noto Sans TC", "Noto Sans JP", "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "WenQuanYi Micro Hei", sans-serif;--font-weight-normal: 400;--font-weight-medium: 500;--font-weight-semibold: 600;--font-weight-bold: 700;--line-height-tight: 1.2;--line-height-normal: 1.5;--line-height-relaxed: 1.65;--text-xs: .75rem;--text-sm: .875rem;--text-base: 1rem;--text-lg: 1.125rem;--text-xl: 1.25rem;--text-2xl: 1.5rem;--text-3xl: 1.875rem;--text-4xl: 2.25rem;--text-5xl: 3rem;--space-0: 0;--space-1: .25rem;--space-2: .5rem;--space-3: .75rem;--space-4: 1rem;--space-5: 1.25rem;--space-6: 1.5rem;--space-8: 2rem;--space-10: 2.5rem;--space-12: 3rem;--space-16: 4rem;--space-20: 5rem;--container-max-width: 75rem;--container-padding: var(--space-4);--radius-sm: .25rem;--radius-md: .5rem;--radius-lg: .75rem;--radius-xl: 1rem;--radius-full: 9999px;--shadow-sm: 0 1px 2px 0 rgb(76 73 130 / .05);--shadow-md: 0 4px 6px -1px rgb(76 73 130 / .07), 0 2px 4px -2px rgb(76 73 130 / .05);--shadow-lg: 0 10px 15px -3px rgb(76 73 130 / .09), 0 4px 6px -4px rgb(76 73 130 / .07);--transition-fast: .15s ease;--transition-base: .2s ease;--breakpoint-sm: 40rem;--breakpoint-md: 48rem;--breakpoint-lg: 64rem;--breakpoint-xl: 80rem}html[data-theme=dark],html.dark{--color-text: #f7f7ff;--color-text-muted: #a0a8d9;--color-background: var(--color-navy-900);--color-surface: var(--color-navy-800);--color-border: var(--color-navy-600);--color-primary: var(--color-violet-500);--color-primary-hover: var(--color-violet-400);--color-primary-text: var(--color-navy-900);--color-secondary: rgb(0 180 216 / .12);--color-secondary-hover: rgb(0 180 216 / .2);--color-secondary-text: var(--color-cyan-400);--color-positive: var(--color-green-400);--color-positive-bg: rgb(45 201 138 / .12);--color-positive-text: var(--color-green-300);--color-owes: var(--color-coral-400);--color-owes-bg: rgb(255 107 87 / .12);--color-owes-text: var(--color-coral-300);--color-error: var(--color-coral-400);--shadow-sm: 0 1px 2px 0 rgb(0 0 0 / .25);--shadow-md: 0 4px 6px -1px rgb(0 0 0 / .35), 0 2px 4px -2px rgb(0 0 0 / .3);--shadow-lg: 0 10px 15px -3px rgb(0 0 0 / .45), 0 4px 6px -4px rgb(0 0 0 / .35)}*,*:before,*:after{box-sizing:border-box}*{margin:0}html{font-size:100%;-webkit-text-size-adjust:100%;text-size-adjust:100%;text-align:start}html:lang(zh){font-family:var(--font-cjk)}body{font-family:var(--font-sans);font-size:var(--text-base);line-height:var(--line-height-normal);color:var(--color-text);background-color:var(--color-background)}#root{min-block-size:100vh;display:flex;flex-direction:column}.hero-title,.section-title,.closing-cta-title{font-family:var(--font-display);letter-spacing:-.02em}.container{inline-size:100%;max-inline-size:var(--container-max-width);margin-inline:auto;padding-inline:var(--container-padding)}.site-main{flex:1}.site-header{position:sticky;inset-block-start:0;z-index:50;background-color:var(--color-background);border-block-end:1px solid var(--color-border);box-shadow:var(--shadow-sm);padding-block:var(--space-3)}.nav-bar{display:flex;align-items:center;justify-content:space-between;gap:var(--space-3);min-block-size:3rem}.brand-link{color:var(--color-text);font-weight:var(--font-weight-bold);font-size:var(--text-lg);line-height:var(--line-height-tight);text-decoration:none;transition:color var(--transition-fast)}.brand-link:hover,.brand-link:focus-visible{color:var(--color-primary)}.brand-link:focus-visible{outline:2px solid var(--color-primary);outline-offset:2px;border-radius:var(--radius-sm)}.nav-links{display:flex;flex-wrap:wrap;align-items:center;justify-content:flex-end;gap:var(--space-2)}@media(min-width:48rem){.site-header{padding-block:var(--space-4)}.nav-bar{gap:var(--space-4)}.nav-links{gap:var(--space-3)}}:root{--header-height: calc(var(--space-3) * 2 + 3rem + 1px)}@media(min-width:48rem){:root{--header-height: calc(var(--space-4) * 2 + 3rem + 1px)}}.theme-toggle{display:inline-flex;align-items:center;justify-content:center;inline-size:2.25rem;block-size:2.25rem;padding:0;border:1px solid var(--color-border);border-radius:var(--radius-full);background-color:var(--color-surface);color:var(--color-text);cursor:pointer;transition:background-color var(--transition-fast),border-color var(--transition-fast),color var(--transition-fast)}.theme-toggle:hover{background-color:var(--color-secondary);border-color:var(--color-secondary-hover);color:var(--color-secondary-text)}.theme-toggle:focus-visible{outline:2px solid var(--color-primary);outline-offset:2px}.theme-toggle svg{inline-size:1.125rem;block-size:1.125rem;flex-shrink:0}.button{display:inline-flex;align-items:center;justify-content:center;gap:var(--space-2);padding-inline:var(--space-4);padding-block:var(--space-3);border-radius:var(--radius-lg);border:1px solid transparent;font-family:inherit;font-size:var(--text-base);font-weight:var(--font-weight-semibold);line-height:var(--line-height-tight);text-decoration:none;cursor:pointer;transition:background-color var(--transition-fast),border-color var(--transition-fast),color var(--transition-fast),box-shadow var(--transition-fast),transform var(--transition-fast)}.button:focus-visible{outline:2px solid var(--color-primary);outline-offset:2px}.button:disabled,.button[aria-disabled=true]{cursor:not-allowed;opacity:.65}.button--primary{background-color:var(--color-primary);color:var(--color-primary-text);border-color:var(--color-primary);box-shadow:var(--shadow-sm)}.button--primary:hover:not(:disabled):not([aria-disabled=true]){background-color:var(--color-primary-hover);border-color:var(--color-primary-hover);box-shadow:var(--shadow-md);transform:translateY(-1px)}.button--secondary{background-color:var(--color-secondary);color:var(--color-secondary-text);border-color:var(--color-border)}.button--secondary:hover:not(:disabled):not([aria-disabled=true]){background-color:var(--color-secondary-hover)}.button--outline{background-color:transparent;color:var(--color-text);border-color:var(--color-border)}.button--outline:hover{background-color:var(--color-surface);border-color:var(--color-primary);color:var(--color-primary)}.button--oauth{background-color:var(--color-background);color:var(--color-text);border-color:var(--color-border);box-shadow:var(--shadow-sm)}.button--oauth:hover:not(:disabled):not([aria-disabled=true]){border-color:var(--color-primary);color:var(--color-primary);box-shadow:var(--shadow-md)}.button--large{padding-inline:var(--space-6);padding-block:var(--space-3);font-size:var(--text-lg)}.button--full{inline-size:100%}.hero{padding-block:var(--space-16) var(--space-12);text-align:center}.hero-inner{display:flex;flex-direction:column;align-items:center;gap:var(--space-12)}.hero-text{max-inline-size:55ch}.hero-badge{display:inline-flex;align-items:center;gap:var(--space-2);padding-inline:var(--space-4);padding-block:var(--space-1);background-color:var(--color-positive-bg);color:var(--color-positive-text);border:1px solid var(--color-green-100);border-radius:var(--radius-full);font-size:var(--text-sm);font-weight:var(--font-weight-semibold);margin-block-end:var(--space-6)}.hero-title{font-family:var(--font-display);font-size:var(--text-4xl);line-height:var(--line-height-tight);font-weight:var(--font-weight-bold);letter-spacing:-.03em;margin-block-end:var(--space-6)}.hero-title-accent{color:var(--color-primary);font-style:italic}@media(min-width:48rem){.hero-title{font-size:var(--text-5xl)}}.hero-subtitle{font-size:var(--text-lg);color:var(--color-text-muted);max-inline-size:50ch;margin-inline:auto;margin-block-end:var(--space-8)}.hero-actions{display:flex;flex-wrap:wrap;justify-content:center;gap:var(--space-4);margin-block-end:var(--space-4)}.hero-reassurance{font-size:var(--text-sm);color:var(--color-text-muted)}@media(min-width:64rem){.hero{padding-block:var(--space-20);text-align:start}.hero-inner{display:grid;grid-template-columns:1fr 1fr;align-items:center;gap:var(--space-16)}.hero-subtitle{margin-inline:0}.hero-actions{justify-content:flex-start}}.field-label{display:block;font-size:var(--text-sm);font-weight:var(--font-weight-semibold);color:var(--color-text);margin-block-end:var(--space-2)}.field-input{display:block;inline-size:100%;padding-inline:var(--space-4);padding-block:var(--space-3);border:1px solid var(--color-border);border-radius:var(--radius-lg);background-color:var(--color-background);color:var(--color-text);font-family:inherit;font-size:var(--text-base);line-height:var(--line-height-tight);margin-block-end:var(--space-5);transition:border-color var(--transition-fast),box-shadow var(--transition-fast)}.field-input:hover{border-color:var(--color-neutral-300)}.field-input:focus{outline:none;border-color:var(--color-primary);box-shadow:0 0 0 3px color-mix(in srgb,var(--color-primary) 18%,transparent)}.auth-section,.checkout-section{display:flex;align-items:center;justify-content:center;min-block-size:calc(100vh - 8rem);padding-block:var(--space-12);padding-inline:var(--container-padding)}.auth-card,.checkout-card{inline-size:100%;max-inline-size:26rem;margin-inline:auto;padding:var(--space-8);background-color:var(--color-surface);border:1px solid var(--color-border);border-radius:var(--radius-xl);box-shadow:var(--shadow-lg)}@media(min-width:48rem){.auth-card,.checkout-card{padding:var(--space-10)}}.auth-header,.checkout-header{display:flex;flex-direction:column;align-items:center;gap:var(--space-4);margin-block-end:var(--space-8)}.auth-title,.checkout-title{font-size:var(--text-3xl);font-weight:var(--font-weight-bold);line-height:var(--line-height-tight);text-align:center;margin-block:0}.auth-subtitle{color:var(--color-text-muted);text-align:center;margin-block:0}.auth-form{display:flex;flex-direction:column}.auth-form .button{margin-block-start:var(--space-2)}.auth-divider{display:flex;align-items:center;gap:var(--space-4);margin-block:var(--space-6);color:var(--color-text-muted);font-size:var(--text-sm);font-weight:var(--font-weight-medium)}.auth-divider:before,.auth-divider:after{content:"";flex:1;block-size:1px;background-color:var(--color-border)}.auth-error,.checkout-error{display:flex;align-items:flex-start;gap:var(--space-3);padding:var(--space-4);border:1px solid var(--color-owes);border-radius:var(--radius-lg);background-color:var(--color-owes-bg);color:var(--color-owes-text);margin-block-end:var(--space-6);font-size:var(--text-sm);font-weight:var(--font-weight-medium);line-height:var(--line-height-normal)}.auth-error svg,.checkout-error svg{flex-shrink:0;inline-size:1.125rem;block-size:1.125rem;margin-block-start:.125rem}.checkout-loading{display:flex;align-items:center;justify-content:center;gap:var(--space-3);color:var(--color-text-muted);font-size:var(--text-lg);font-weight:var(--font-weight-medium);text-align:center}.spin{animation:spin 1s linear infinite}@keyframes spin{0%{transform:rotate(0)}to{transform:rotate(360deg)}}.checkout-lead{text-align:center;color:var(--color-text-muted);margin-block:0}.plans{display:grid;grid-template-columns:1fr;gap:var(--space-6)}@media(min-width:48rem){.plans{grid-template-columns:repeat(2,1fr)}}.plan{padding:var(--space-6);border:1px solid var(--color-border);border-radius:var(--radius-lg);background-color:var(--color-background)}.plan--featured{border-color:var(--color-primary);box-shadow:var(--shadow-md)}.plan-name{font-size:var(--text-xl);font-weight:var(--font-weight-semibold);margin-block-end:var(--space-2)}.plan-price{font-size:var(--text-3xl);font-weight:var(--font-weight-bold);margin-block-end:var(--space-4)}.plan-features{list-style:none;padding-inline-start:0;margin-block-end:var(--space-6)}.plan-features li{padding-block:var(--space-2);border-block-end:1px solid var(--color-border)}.plan-features li:last-child{border-block-end:none}.site-footer{background-color:var(--color-surface);border-block-start:1px solid var(--color-border);padding-block:var(--space-8);color:var(--color-text-muted);font-size:var(--text-sm)}.footer-inner{display:flex;flex-direction:column;flex-wrap:wrap;align-items:center;justify-content:center;gap:var(--space-3);text-align:center}.footer-inner p{max-inline-size:60ch}@media(min-width:48rem){.footer-inner{flex-direction:row;justify-content:space-between;text-align:start}}.language-picker{display:flex;align-items:center;gap:var(--space-2)}.language-picker label{font-size:var(--text-sm);color:var(--color-text-muted)}.language-picker select{inline-size:max-content;padding-inline:var(--space-3);padding-block:var(--space-1);border:1px solid var(--color-border);border-radius:var(--radius-md);background-color:var(--color-background);color:var(--color-text);font-family:inherit;font-size:var(--text-sm);cursor:pointer}.language-picker select:hover,.language-picker select:focus{border-color:var(--color-primary);outline:none}.hero-eyebrow{display:block;font-size:var(--text-sm);font-weight:var(--font-weight-semibold);color:var(--color-primary);text-transform:uppercase;letter-spacing:.05em;margin-block-end:var(--space-4)}.landing-section{padding-block:var(--space-16);scroll-margin-top:var(--header-height)}.section-header{text-align:center;margin-block-end:var(--space-12)}.section-title{font-size:var(--text-3xl);line-height:var(--line-height-tight);font-weight:var(--font-weight-bold);margin-block-end:var(--space-4)}.section-lead{font-size:var(--text-lg);color:var(--color-text-muted);max-inline-size:55ch;margin-inline:auto}.trust-section{background-color:var(--color-surface)}.trust-grid{display:grid;grid-template-columns:1fr;gap:var(--space-6)}@media(min-width:48rem){.trust-grid{grid-template-columns:repeat(2,1fr)}}@media(min-width:64rem){.trust-grid{grid-template-columns:repeat(4,1fr)}}.trust-card{padding:var(--space-6);background-color:var(--color-background);border:1px solid var(--color-border);border-radius:var(--radius-lg);box-shadow:var(--shadow-sm)}.trust-card-title{font-size:var(--text-lg);font-weight:var(--font-weight-semibold);line-height:var(--line-height-tight);margin-block-end:var(--space-2)}.trust-card p{color:var(--color-text-muted)}.icon-chip{display:inline-flex;align-items:center;justify-content:center;inline-size:2.5rem;block-size:2.5rem;border-radius:var(--radius-lg);flex-shrink:0}.icon-chip svg{inline-size:1.25rem;block-size:1.25rem}.icon-chip--violet{background-color:var(--color-violet-50);color:var(--color-violet-600)}.icon-chip--cyan{background-color:var(--color-cyan-50);color:var(--color-cyan-600)}.icon-chip--green{background-color:var(--color-green-50);color:var(--color-green-600)}.icon-chip--coral{background-color:var(--color-coral-50);color:var(--color-coral-600)}.features-grid{display:grid;grid-template-columns:1fr;gap:var(--space-6)}@media(min-width:48rem){.features-grid{grid-template-columns:repeat(2,1fr)}}@media(min-width:64rem){.features-grid{grid-template-columns:repeat(3,1fr)}}.feature-card{padding:var(--space-6);background-color:var(--color-surface);border:1px solid var(--color-border);border-radius:var(--radius-lg);box-shadow:var(--shadow-md)}.feature-card__title,.feature-card-title{font-size:var(--text-xl);font-weight:var(--font-weight-semibold);line-height:var(--line-height-tight);margin-block-end:var(--space-3)}.feature-card__description,.feature-card p{color:var(--color-text-muted)}.how-it-works-section{background-color:var(--color-surface)}.how-it-works-steps{display:grid;grid-template-columns:1fr;gap:var(--space-8);list-style:none;padding-inline-start:0;margin-block:0;counter-reset:step}@media(min-width:48rem){.how-it-works-steps{grid-template-columns:repeat(3,1fr)}}.how-it-works-step{display:flex;flex-direction:column;align-items:flex-start;gap:var(--space-4)}.how-it-works-step h3{font-size:var(--text-xl);font-weight:var(--font-weight-semibold);line-height:var(--line-height-tight)}.how-it-works-step p{color:var(--color-text-muted)}.social-proof-section{background-color:var(--color-surface);text-align:center}.social-proof-card{max-inline-size:60ch;margin-inline:auto;margin-block-start:var(--space-8)}.social-proof-quote{font-size:var(--text-2xl);line-height:var(--line-height-relaxed);font-weight:var(--font-weight-medium);color:var(--color-text);margin-block-end:var(--space-4)}.social-proof-attribution{font-size:var(--text-base);color:var(--color-text-muted)}.closing-cta-section{padding-block:var(--space-20);text-align:center}.closing-cta-inner{max-inline-size:55ch;margin-inline:auto}.closing-cta-title{font-size:var(--text-4xl);line-height:var(--line-height-tight);font-weight:var(--font-weight-bold);margin-block-end:var(--space-4)}@media(min-width:48rem){.closing-cta-title{font-size:var(--text-5xl)}}.closing-cta-lead{font-size:var(--text-xl);color:var(--color-text-muted);margin-block-end:var(--space-10)}.auth-subtitle{text-align:center;color:var(--color-text-muted);margin-block:0}.hero-mockup{inline-size:100%;max-inline-size:22rem;margin-inline:auto;padding:var(--space-6);background-color:var(--color-background);border:1px solid var(--color-border);border-radius:var(--radius-xl);box-shadow:var(--shadow-lg);text-align:start}@media(min-width:48rem){.hero-mockup{padding:var(--space-8)}}.hero-mockup-header{margin-block-end:var(--space-5)}.hero-mockup-title{font-family:var(--font-sans);font-size:var(--text-lg);font-weight:var(--font-weight-semibold);line-height:var(--line-height-tight);color:var(--color-text)}.hero-mockup-total{color:var(--color-text-muted);font-weight:var(--font-weight-normal)}.hero-mockup-avatars{display:flex;list-style:none;padding-inline-start:0;margin-block-end:var(--space-6);gap:var(--space-2)}.hero-mockup-avatar{display:inline-flex;align-items:center;justify-content:center;inline-size:2.5rem;block-size:2.5rem;border-radius:var(--radius-full);color:var(--color-white);font-size:var(--text-xs);font-weight:var(--font-weight-bold);flex-shrink:0}.hero-mockup-participants{display:flex;flex-direction:column;gap:var(--space-3);list-style:none;padding-inline-start:0;margin-block:0}.hero-mockup-participant{display:flex;align-items:center;justify-content:space-between;gap:var(--space-4);padding-block:var(--space-3);border-block-end:1px solid var(--color-border)}.hero-mockup-participant:last-child{border-block-end:none}.hero-mockup-name{color:var(--color-text);font-weight:var(--font-weight-medium)}.hero-mockup-owes{color:var(--color-owes);font-weight:var(--font-weight-semibold)}.hero-mockup-gets{color:var(--color-positive);font-weight:var(--font-weight-semibold)}.hero-mockup-footer{display:flex;align-items:center;justify-content:center;gap:var(--space-2);margin-block-start:var(--space-6);padding-block-start:var(--space-5);border-block-start:1px solid var(--color-border);color:var(--color-text-muted);font-size:var(--text-sm)}