:root {
    color-scheme: light dark;
    --tool-background: #eef2f5;
    --tool-surface: #ffffff;
    --tool-surface-subtle: #f7f9fa;
    --tool-text: #17242e;
    --tool-muted: #65747f;
    --tool-border: #ccd7de;
    --tool-accent: #176b87;
    --tool-accent-strong: #0d536c;
    --tool-accent-soft: #dcecf2;
    --tool-positive: #18734a;
    --tool-negative: #b34339;
    --tool-shadow: 0 18px 50px rgba(23, 36, 46, 0.08);
}

@media (prefers-color-scheme: dark) {
    :root {
        --tool-background: #11191e;
        --tool-surface: #19242a;
        --tool-surface-subtle: #202d34;
        --tool-text: #edf4f6;
        --tool-muted: #a5b4bc;
        --tool-border: #35464f;
        --tool-accent: #73bfd6;
        --tool-accent-strong: #9bd5e5;
        --tool-accent-soft: #263f49;
        --tool-positive: #69c494;
        --tool-negative: #ef9188;
        --tool-shadow: 0 18px 50px rgba(0, 0, 0, 0.2);
    }
}

* {
    box-sizing: border-box;
}

body {
    min-height: 100vh;
    margin: 0;
    background: var(--tool-background);
    color: var(--tool-text);
    font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
    line-height: 1.5;
}

.tool-shell {
    width: min(calc(100% - 2rem), 760px);
    margin: 0 auto;
    padding: clamp(2.5rem, 8vw, 5rem) 0;
}

.tool-shell--compact {
    max-width: 560px;
}

.tool-eyebrow,
.tool-data {
    font-family: ui-monospace, "SFMono-Regular", Consolas, monospace;
}

.tool-eyebrow {
    margin: 0 0 0.5rem;
    color: var(--tool-accent);
    font-size: 0.78rem;
    font-weight: 700;
    letter-spacing: 0.12em;
    text-transform: uppercase;
}

.tool-title {
    max-width: 650px;
    margin: 0;
    font-size: clamp(2.35rem, 7vw, 4.75rem);
    line-height: 0.96;
    letter-spacing: -0.055em;
}

.tool-intro {
    max-width: 600px;
    margin: 1.25rem 0 2.5rem;
    color: var(--tool-muted);
    font-size: 1.05rem;
}

.tool-card {
    padding: clamp(1rem, 4vw, 2rem);
    border: 1px solid var(--tool-border);
    border-radius: 16px;
    background: var(--tool-surface);
    box-shadow: var(--tool-shadow);
}

.tool-label,
.column-labels {
    color: var(--tool-muted);
    font-size: 0.78rem;
    font-weight: 700;
    letter-spacing: 0.06em;
    text-transform: uppercase;
}

input,
button {
    font: inherit;
}

input {
    min-width: 0;
    width: 100%;
    padding: 0.75rem 0.85rem;
    border: 1px solid var(--tool-border);
    border-radius: 8px;
    background: var(--tool-surface-subtle);
    color: var(--tool-text);
}

input:focus-visible,
button:focus-visible {
    outline: 3px solid color-mix(in srgb, var(--tool-accent) 38%, transparent);
    outline-offset: 2px;
}

button {
    border: 0;
    border-radius: 8px;
    cursor: pointer;
}

.tool-field {
    display: grid;
    gap: 0.5rem;
}

.tool-readout {
    display: flex;
    min-height: 5rem;
    align-items: center;
    margin-top: 1.5rem;
    padding: 1rem 1.25rem;
    border-left: 4px solid var(--tool-accent);
    background: var(--tool-accent-soft);
    color: var(--tool-accent-strong);
    font-size: clamp(1.4rem, 5vw, 2rem);
    font-weight: 750;
}

.tool-note {
    margin: 0.75rem 0 0;
    color: var(--tool-muted);
    font-size: 0.82rem;
}

.column-labels,
.person-row {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(110px, 0.55fr) 42px;
    gap: 0.75rem;
    align-items: center;
}

.column-labels {
    margin-bottom: 0.45rem;
}

.person-row {
    margin-bottom: 0.75rem;
}

.money-field {
    position: relative;
}

.money-field input {
    padding-right: 2.3rem;
}

.currency {
    position: absolute;
    top: 50%;
    right: 0.85rem;
    color: var(--tool-muted);
    transform: translateY(-50%);
    pointer-events: none;
}

.remove-person {
    width: 42px;
    height: 42px;
    background: transparent;
    color: var(--tool-muted);
    font-size: 1.4rem;
}

.remove-person:hover {
    background: var(--tool-surface-subtle);
    color: var(--tool-negative);
}

.actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    margin-top: 1rem;
}

.add-person {
    padding: 0.75rem 1rem;
    background: var(--tool-accent-soft);
    color: var(--tool-accent-strong);
    font-weight: 700;
}

.calculate {
    flex: 1;
    min-width: 170px;
    padding: 0.75rem 1.2rem;
    background: var(--tool-accent);
    color: #ffffff;
    font-weight: 700;
}

@media (prefers-color-scheme: dark) {
    .calculate {
        color: #102129;
    }
}

.privacy {
    margin: 1rem 0 0;
    color: var(--tool-muted);
    font-size: 0.8rem;
}

.error {
    margin: 1rem 0 0;
    color: var(--tool-negative);
    font-weight: 600;
}

.results {
    margin-top: 1.5rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--tool-border);
}

.summary {
    display: flex;
    flex-wrap: wrap;
    gap: 0.4rem 1.5rem;
    margin-bottom: 1.25rem;
    color: var(--tool-muted);
    font-family: ui-monospace, "SFMono-Regular", Consolas, monospace;
    font-size: 0.9rem;
}

.summary strong {
    color: var(--tool-text);
}

.results h2 {
    margin: 0 0 0.75rem;
    font-size: 1.25rem;
}

.payments {
    margin: 0;
    padding: 0;
    list-style: none;
}

.payment {
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr);
    gap: 0.6rem;
    align-items: center;
    padding: 0.85rem 0;
    border-top: 1px solid var(--tool-border);
}

.payment:first-child {
    border-top: 0;
}

.payment strong:last-child {
    text-align: right;
}

.amount {
    padding: 0.25rem 0.5rem;
    border-radius: 999px;
    background: var(--tool-accent-soft);
    color: var(--tool-accent-strong);
    font-family: ui-monospace, "SFMono-Regular", Consolas, monospace;
    font-weight: 700;
    white-space: nowrap;
}

.settled {
    margin: 0;
    color: var(--tool-positive);
    font-weight: 700;
}

[hidden] {
    display: none !important;
}

@media (max-width: 520px) {
    .tool-shell {
        padding: 2.5rem 0;
    }

    .column-labels,
    .person-row {
        grid-template-columns: minmax(0, 1fr) minmax(95px, 0.65fr) 38px;
        gap: 0.5rem;
    }

    .remove-person {
        width: 38px;
    }

    .payment {
        grid-template-columns: 1fr auto;
    }

    .payment strong:last-child {
        grid-column: 1;
        text-align: left;
    }

    .payment .amount {
        grid-column: 2;
        grid-row: 1 / span 2;
    }
}

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        scroll-behavior: auto !important;
    }
}