:root {
    --bg: #f6f7fb;
    --surface: #ffffff;
    --surface-soft: #f0f1ff;
    --primary: #5b5bd6;
    --primary-dark: #4141ad;
    --navy: #171a2b;
    --text: #303348;
    --muted: #74788d;
    --border: #e4e6ef;
    --success: #16845b;
    --success-soft: #e8f7f0;
    --danger: #c94c5d;
    --danger-soft: #fff0f2;
    --shadow: 0 18px 45px rgba(32, 36, 67, .08);
    --radius-lg: 24px;
    --radius-md: 16px;
    --radius-sm: 10px;
}
* { box-sizing: border-box; }
html { color-scheme: light; }
body { margin: 0; min-height: 100vh; background: var(--bg); color: var(--text); font-family: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; line-height: 1.55; }
a { color: inherit; }
button, input, textarea, select { font: inherit; }
.app-header { position: sticky; top: 0; z-index: 20; background: rgba(246,247,251,.88); border-bottom: 1px solid rgba(228,230,239,.9); backdrop-filter: blur(18px); }
.nav-shell { max-width: 1120px; min-height: 72px; margin: 0 auto; padding: 0 24px; display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.brand { display: inline-flex; align-items: center; gap: 10px; color: var(--navy); text-decoration: none; font-size: 1.2rem; font-weight: 800; letter-spacing: -.03em; }
.brand-mark { display: grid; place-items: center; width: 36px; height: 36px; border-radius: 11px; background: var(--primary); color: white; box-shadow: 0 7px 16px rgba(91,91,214,.28); }
.nav-actions { display: flex; align-items: center; gap: 18px; }
.nav-link { color: var(--navy); text-decoration: none; font-weight: 650; font-size: .94rem; }
.nav-link--muted, .user-greeting { color: var(--muted); }
.user-greeting { font-size: .9rem; }
.page-shell { width: min(1120px, calc(100% - 48px)); margin: 0 auto; padding: 48px 0 72px; }
h1, h2, h3, p { margin-top: 0; }
h1 { margin-bottom: 14px; color: var(--navy); font-size: clamp(2rem, 5vw, 3.5rem); line-height: 1.04; letter-spacing: -.045em; }
h2 { margin-bottom: 0; color: var(--navy); font-size: clamp(1.45rem, 3vw, 2rem); line-height: 1.15; letter-spacing: -.03em; }
h3 { color: var(--navy); letter-spacing: -.02em; }
.eyebrow { display: block; margin-bottom: 10px; color: var(--primary); font-size: .76rem; font-weight: 800; letter-spacing: .1em; text-transform: uppercase; }
.page-intro, .form-heading p { max-width: 620px; margin-bottom: 0; color: var(--muted); font-size: 1.04rem; }
.hero, .group-hero { margin-bottom: 44px; display: flex; justify-content: space-between; align-items: flex-end; gap: 32px; }
.hero--dashboard { padding: 34px; border: 1px solid var(--border); border-radius: var(--radius-lg); background: linear-gradient(135deg, #fff 0%, #f0f1ff 100%); box-shadow: var(--shadow); }
.hero--dashboard h1, .group-hero h1 { font-size: clamp(2rem, 4vw, 3rem); }
.hero-actions, .button-row { display: flex; flex-wrap: wrap; gap: 12px; }
.btn { min-height: 48px; padding: 12px 20px; border: 1px solid transparent; border-radius: 13px; display: inline-flex; align-items: center; justify-content: center; text-decoration: none; font-weight: 750; cursor: pointer; transition: transform .18s, box-shadow .18s, background .18s; }
.btn:hover { transform: translateY(-2px); }
.btn-primary { background: var(--primary); color: white; box-shadow: 0 9px 20px rgba(91,91,214,.24); }
.btn-primary:hover { background: var(--primary-dark); }
.btn-secondary { border-color: var(--border); background: var(--surface); color: var(--navy); }
.btn-secondary:hover { box-shadow: 0 8px 18px rgba(32,36,67,.08); }
.btn-small { min-height: 40px; padding: 8px 15px; border-radius: 11px; font-size: .9rem; }
.section-heading { margin: 0 0 20px; display: flex; align-items: end; justify-content: space-between; gap: 20px; }
.section-heading--compact { margin-bottom: 20px; align-items: center; }
.section-heading--compact .eyebrow { margin-bottom: 5px; }
.count-pill, .role-pill { border-radius: 999px; padding: 6px 11px; background: var(--surface-soft); color: var(--primary-dark); font-size: .78rem; font-weight: 750; }
.group-grid { display: grid; grid-template-columns: repeat(2, minmax(0,1fr)); gap: 16px; }
.group-card { min-width: 0; padding: 22px; border: 1px solid var(--border); border-radius: var(--radius-md); background: var(--surface); display: grid; grid-template-columns: 48px minmax(0,1fr) auto; align-items: center; gap: 16px; color: inherit; text-decoration: none; transition: transform .18s, border-color .18s, box-shadow .18s; }
.group-card:hover { transform: translateY(-3px); border-color: #c9c9ef; box-shadow: var(--shadow); }
.group-card__icon, .expense-icon, .transaction-avatar { display: grid; place-items: center; flex: 0 0 auto; border-radius: 14px; background: var(--surface-soft); color: var(--primary); font-weight: 850; }
.group-card__icon { width: 48px; height: 48px; }
.group-card__body { min-width: 0; }
.group-card h3 { margin-bottom: 3px; font-size: 1.08rem; }
.group-card p { margin-bottom: 7px; overflow: hidden; color: var(--muted); font-size: .9rem; text-overflow: ellipsis; white-space: nowrap; }
.group-card__meta { color: var(--muted); font-size: .78rem; }
.group-card__arrow { color: var(--primary); font-size: 1.35rem; }
.empty-state { padding: 60px 24px; border: 1px dashed #cfd1df; border-radius: var(--radius-lg); background: var(--surface); text-align: center; }
.empty-state__icon { width: 54px; height: 54px; margin: 0 auto 18px; border-radius: 17px; display: grid; place-items: center; background: var(--surface-soft); color: var(--primary); font-size: 1.7rem; }
.empty-state p { margin: 10px auto 22px; color: var(--muted); }
.landing-hero { min-height: 520px; display: grid; grid-template-columns: 1.2fr .8fr; align-items: center; gap: clamp(40px,8vw,100px); }
.landing-hero__copy > p { max-width: 640px; margin-bottom: 28px; color: var(--muted); font-size: 1.15rem; }
.balance-preview { padding: 32px; border-radius: 30px; background: var(--navy); color: white; box-shadow: 0 30px 70px rgba(23,26,43,.22); transform: rotate(2deg); }
.balance-preview__label { display: block; margin-bottom: 38px; color: #b9bdd0; }
.balance-preview strong { display: block; font-size: .9rem; }
.balance-preview__amount { display: block; margin: 4px 0 34px; font-size: 3rem; font-weight: 850; letter-spacing: -.05em; }
.avatar-row { display: flex; align-items: center; }
.avatar-row span { width: 38px; height: 38px; margin-right: -8px; border: 3px solid var(--navy); border-radius: 50%; display: grid; place-items: center; background: var(--primary); font-size: .8rem; font-weight: 800; }
.avatar-row small { margin-left: 20px; color: #b9bdd0; }
.breadcrumb { margin-bottom: 24px; display: flex; gap: 9px; align-items: center; color: var(--muted); font-size: .88rem; }
.breadcrumb a { color: var(--primary); text-decoration: none; }
.summary-grid { margin-bottom: 24px; display: grid; grid-template-columns: repeat(3,1fr); gap: 16px; }
.metric-card, .share-card { min-height: 150px; padding: 22px; border: 1px solid var(--border); border-radius: var(--radius-md); background: var(--surface); text-align: left; }
.metric-card > span, .share-card > span { display: block; margin-bottom: 18px; color: var(--muted); font-size: .85rem; }
.metric-card > strong, .share-card > strong { display: block; color: var(--navy); font-size: 1.65rem; letter-spacing: -.04em; }
.metric-card small { color: var(--muted); font-size: .78rem; letter-spacing: 0; }
.metric-card--positive { background: var(--success-soft); border-color: #ccebdd; }
.metric-card--positive > strong { color: var(--success); }
.metric-card--negative { background: var(--danger-soft); border-color: #f1d1d6; }
.metric-card--negative > strong { color: var(--danger); }
.share-card { cursor: pointer; color: inherit; }
.share-card:hover { border-color: var(--primary); }
.copy-hint { display: block; margin-top: 5px; color: var(--primary) !important; }
.copied { background: var(--success-soft); border-color: var(--success); }
.content-grid { display: grid; grid-template-columns: .85fr 1.15fr; align-items: start; gap: 20px; }
.content-card, .form-shell { padding: 28px; border: 1px solid var(--border); border-radius: var(--radius-lg); background: var(--surface); box-shadow: 0 10px 30px rgba(32,36,67,.05); }
.transaction-list, .expense-list, .member-list { display: grid; gap: 4px; }
.transaction-row, .expense-row, .member-row { min-width: 0; padding: 13px 0; border-bottom: 1px solid var(--border); display: flex; align-items: center; gap: 12px; }
.transaction-row:last-child, .expense-row:last-child, .member-row:last-child { border-bottom: 0; }
.transaction-avatar, .expense-icon { width: 42px; height: 42px; }
.transaction-row p { flex: 1; margin: 0; font-size: .9rem; }
.transaction-row > span { color: var(--navy); font-weight: 800; }
.expense-row__body, .member-row__body { min-width: 0; flex: 1; display: grid; }
.expense-row__body span, .member-row__body span { color: var(--muted); font-size: .8rem; }
.expense-row__amount { display: grid; text-align: right; }
.expense-row__amount span { color: var(--muted); font-size: .72rem; }
.icon-action { width: 34px; height: 34px; border-radius: 10px; display: grid; place-items: center; text-decoration: none; font-size: 1.25rem; }
.icon-action--danger { color: var(--danger); }
.icon-action--danger:hover { background: var(--danger-soft); }
.inline-empty { padding: 22px 0; display: flex; align-items: center; gap: 14px; color: var(--muted); }
.inline-empty > span { width: 42px; height: 42px; border-radius: 50%; display: grid; place-items: center; background: var(--surface-soft); color: var(--primary); }
.inline-empty strong { color: var(--navy); }
.inline-empty p { margin: 2px 0 0; font-size: .85rem; }
.text-link { color: var(--primary); text-decoration: none; font-size: .88rem; font-weight: 750; }
.text-link--danger { color: var(--danger); }
.form-shell { max-width: 760px; margin: 0 auto; }
.form-shell--narrow { max-width: 660px; }
.form-heading { margin-bottom: 28px; }
.form-heading h1 { font-size: clamp(2rem,4vw,2.8rem); }
.stack-form { display: grid; gap: 21px; }
.field { display: grid; gap: 8px; }
.field label, .stack-form > p > label { color: var(--navy); font-size: .88rem; font-weight: 750; }
.form-control { width: 100%; padding: 14px 15px; border: 1px solid #d9dce8; border-radius: 12px; background: white; color: var(--text); outline: none; transition: border .18s, box-shadow .18s; }
textarea.form-control { resize: vertical; }
.form-control:focus { border-color: var(--primary); box-shadow: 0 0 0 4px rgba(91,91,214,.12); }
.amount-input { font-size: 1.65rem; font-weight: 800; letter-spacing: -.03em; }
.member-select { min-height: 130px; }
.field-suffix { margin-left: 6px; color: var(--muted); font-weight: 500; }
.field-note { padding: 14px; border-radius: 12px; background: var(--surface-soft); display: grid; }
.field-note span { color: var(--muted); font-size: .82rem; }
.form-error { color: var(--danger); font-size: .8rem; }
.members-card { max-width: 760px; margin: 20px auto 0; }
.role-pill { background: var(--success-soft); color: var(--success); }
.flash-stack { margin-bottom: 20px; display: grid; gap: 8px; }
.alert { padding: 13px 16px; border: 1px solid var(--border); border-radius: 12px; background: var(--surface); }
.alert-success { border-color: #ccebdd; background: var(--success-soft); color: var(--success); }
.alert-danger { border-color: #f1d1d6; background: var(--danger-soft); color: var(--danger); }
.alert-info { background: var(--surface-soft); color: var(--primary-dark); }
.muted { color: var(--muted); }

@media (max-width: 820px) {
    .page-shell { width: min(100% - 28px, 680px); padding: 28px 0 48px; }
    .nav-shell { min-height: 64px; padding: 0 14px; }
    .user-greeting, .nav-actions .nav-link:first-of-type { display: none; }
    .hero, .group-hero { align-items: flex-start; flex-direction: column; }
    .hero--dashboard { padding: 24px; }
    .group-grid, .summary-grid, .content-grid, .landing-hero { grid-template-columns: 1fr; }
    .landing-hero { min-height: auto; gap: 44px; }
    .balance-preview { max-width: 460px; transform: none; }
    .summary-grid { gap: 10px; }
    .metric-card, .share-card { min-height: auto; }
    .content-grid { gap: 14px; }
}
@media (max-width: 520px) {
    .brand { font-size: 1.08rem; }
    .brand-mark { width: 34px; height: 34px; }
    .nav-actions { gap: 10px; }
    .nav-actions .btn { min-height: 40px; padding: 8px 12px; }
    .page-shell { width: calc(100% - 24px); }
    h1 { font-size: 2.25rem; }
    .hero--dashboard, .content-card, .form-shell { padding: 20px; border-radius: 18px; }
    .hero-actions, .button-row { width: 100%; }
    .hero-actions .btn, .button-row .btn, .button-row input { flex: 1; }
    .group-grid { gap: 10px; }
    .group-card { padding: 16px; grid-template-columns: 42px minmax(0,1fr) auto; gap: 12px; }
    .group-card__icon { width: 42px; height: 42px; border-radius: 12px; }
    .group-card p { display: none; }
    .group-card__meta { font-size: .72rem; }
    .section-heading { align-items: center; }
    .balance-preview { padding: 25px; border-radius: 22px; }
    .balance-preview__amount { font-size: 2.55rem; }
    .breadcrumb { overflow-x: auto; white-space: nowrap; }
    .transaction-row, .expense-row, .member-row { gap: 9px; }
    .transaction-avatar, .expense-icon { width: 38px; height: 38px; border-radius: 12px; }
    .expense-row__amount { font-size: .9rem; }
}

.form-footer { margin: 24px 0 0; padding-top: 20px; border-top: 1px solid var(--border); color: var(--muted); text-align: center; }
.code-input { text-align: center; text-transform: uppercase; letter-spacing: .16em; font-size: 1.35rem; font-weight: 800; }

.text-button { padding: 0; border: 0; background: transparent; font: inherit; cursor: pointer; }
.text-button--danger { color: var(--danger); font-size: .88rem; font-weight: 750; }
.nav-logout { margin: 0; }
.btn-danger { border-color: #f1d1d6; background: var(--danger-soft); color: var(--danger); }
.icon-action { border: 0; background: transparent; cursor: pointer; }
.expense-row form { margin: 0; }
.checkbox-panel, .split-options { padding: 14px 16px; border: 1px solid var(--border); border-radius: 12px; }
.checkbox-panel ul, .split-options ul { margin: 0; padding: 0; display: grid; gap: 10px; list-style: none; }
.checkbox-panel li label, .split-options li label { display: flex; align-items: center; gap: 9px; cursor: pointer; }
.checkbox-panel input, .split-options input { width: 18px; height: 18px; accent-color: var(--primary); }
.custom-splits { display: grid; gap: 10px; }
.custom-splits[hidden], .custom-row[hidden] { display: none; }
.custom-row { padding: 10px 0; display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.money-field { max-width: 180px; display: flex; align-items: center; gap: 8px; }
.money-field small { color: var(--muted); }
.split-total { margin: 6px 0 0; color: var(--muted); text-align: right; }
.repay-form { margin: 4px 0 12px 54px; display: grid; grid-template-columns: 1fr auto; gap: 8px; }
.history-card { margin-top: 20px; }
.repayment-row { padding: 13px 0; border-bottom: 1px solid var(--border); display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.repayment-row:last-child { border-bottom: 0; }
.repayment-row > div { display: grid; }
.repayment-row span { color: var(--muted); font-size: .82rem; }
.status-pill { border-radius: 999px; padding: 6px 10px; background: var(--surface-soft); font-size: .76rem !important; font-weight: 750; }
.status-pill--confirmed { background: var(--success-soft); color: var(--success) !important; }
.danger-zone { max-width: 760px; margin: 20px auto 0; padding: 22px; border: 1px solid #f1d1d6; border-radius: var(--radius-md); background: var(--danger-soft); display: flex; align-items: center; justify-content: space-between; gap: 20px; }
.danger-zone p { margin: 3px 0 0; color: var(--muted); font-size: .86rem; }
.login-shell { max-width: 460px; margin: 40px auto; padding: 36px; border: 1px solid var(--border); border-radius: var(--radius-lg); background: var(--surface); box-shadow: var(--shadow); text-align: center; }
.login-shell h1 { font-size: 2.25rem; }
.login-shell > p { margin-bottom: 26px; color: var(--muted); }
.login-shell .stack-form { text-align: left; }
.login-mark { width: 52px; height: 52px; margin: 0 auto 20px; border-radius: 16px; display: grid; place-items: center; background: var(--primary); color: white; font-size: 1.3rem; font-weight: 850; }
.google-button { min-height: 52px; padding: 12px 18px; border: 1px solid var(--border); border-radius: 13px; display: flex; align-items: center; justify-content: center; gap: 12px; color: var(--navy); text-decoration: none; font-weight: 750; }
.google-button:hover { border-color: #c9c9ef; box-shadow: 0 8px 20px rgba(32,36,67,.08); }
.google-g { color: #4285f4; font-size: 1.25rem; font-weight: 900; }
.dev-notice { margin-bottom: 22px; padding: 13px; border-radius: 12px; background: #fff8df; display: grid; color: #775d12; font-size: .82rem; text-align: left; }
@media (max-width:520px) {
 .custom-row { align-items: flex-start; flex-direction: column; }
 .money-field { max-width: none; width: 100%; }
 .repay-form { margin-left: 0; }
 .danger-zone, .repayment-row { align-items: stretch; flex-direction: column; }
 .login-shell { margin: 12px auto; padding: 25px 20px; }
}