:root {
    --bg: #f4f5f2;
    --surface: #ffffff;
    --surface-muted: #f7f8f5;
    --ink: #17221b;
    --muted: #667168;
    --line: #dfe4de;
    --accent: #17633a;
    --accent-hover: #104c2b;
    --accent-soft: #e3f0e7;
    --danger: #b42318;
    --danger-soft: #fef3f2;
    --radius-sm: 8px;
    --radius-md: 14px;
    --radius-lg: 22px;
    --shadow: 0 18px 55px rgba(35, 50, 41, 0.09);
}

* { box-sizing: border-box; }

html { color-scheme: light; }

body {
    margin: 0;
    min-width: 320px;
    background: var(--bg);
    color: var(--ink);
    font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    font-size: 16px;
    line-height: 1.5;
}

button, input { font: inherit; }

.site-header,
main,
footer {
    width: min(1180px, calc(100% - 48px));
    margin-inline: auto;
}

.site-header {
    min-height: 78px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    border-bottom: 1px solid var(--line);
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    color: var(--ink);
    font-size: 15px;
    font-weight: 700;
    letter-spacing: -0.01em;
    text-decoration: none;
}

.brand-mark {
    width: 30px;
    height: 30px;
    display: grid;
    place-items: center;
    border-radius: 50%;
    background: var(--ink);
}

.brand-mark::before,
.brand-mark::after,
.brand-mark span {
    content: "";
    position: absolute;
    width: 3px;
    background: var(--surface);
    border-radius: 99px;
    transform-origin: bottom;
}

.brand-mark { position: relative; }
.brand-mark::before { height: 7px; transform: translate(-5px, 3px); }
.brand-mark span { height: 11px; transform: translate(0, 1px); }
.brand-mark::after { height: 15px; transform: translate(5px, -1px); }

.header-note {
    color: var(--muted);
    font-size: 13px;
}

.intro {
    max-width: 790px;
    padding: 76px 0 42px;
}

.eyebrow,
.step-label {
    margin: 0 0 14px;
    color: var(--accent);
    font-size: 11px;
    font-weight: 700;
    letter-spacing: .13em;
    text-transform: uppercase;
}

h1 {
    max-width: 760px;
    margin: 0;
    font-family: Georgia, "Times New Roman", serif;
    font-size: clamp(42px, 6vw, 70px);
    font-weight: 400;
    letter-spacing: -0.045em;
    line-height: 1.02;
}

.intro > p:last-child {
    max-width: 610px;
    margin: 24px 0 0;
    color: var(--muted);
    font-size: 18px;
}

.calculator-shell {
    display: grid;
    grid-template-columns: minmax(0, 1.1fr) minmax(360px, .9fr);
    overflow: hidden;
    border: 1px solid var(--line);
    border-radius: var(--radius-lg);
    background: var(--surface);
    box-shadow: var(--shadow);
}

.calculator-form,
.results { padding: 44px; }

.form-heading {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 24px;
    margin-bottom: 34px;
}

.form-heading .step-label { margin-bottom: 7px; }

h2 { margin: 0; font-size: 24px; letter-spacing: -0.025em; }

.secure-note {
    padding: 7px 10px;
    border-radius: 999px;
    background: var(--surface-muted);
    color: var(--muted);
    font-size: 11px;
    font-weight: 600;
}

.error-summary {
    display: flex;
    flex-direction: column;
    gap: 2px;
    margin: -10px 0 24px;
    padding: 14px 16px;
    border: 1px solid #fecdca;
    border-radius: var(--radius-sm);
    background: var(--danger-soft);
    color: var(--danger);
    font-size: 13px;
}

.field-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 22px 16px;
}

.field-wide { grid-column: 1 / -1; }
.field { display: flex; flex-direction: column; gap: 8px; }
.field label, legend { color: var(--ink); font-size: 13px; font-weight: 650; }
.field small, .choice-card small { color: var(--muted); font-size: 12px; }
.field .field-error { color: var(--danger); }

.input-wrap {
    min-height: 50px;
    display: flex;
    align-items: center;
    border: 1px solid var(--line);
    border-radius: var(--radius-sm);
    background: var(--surface);
    transition: border-color .16s ease, box-shadow .16s ease;
}

.input-wrap:focus-within {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(23, 99, 58, .12);
}

.input-wrap span { flex: 0 0 auto; color: var(--muted); font-size: 14px; }
.input-wrap.prefix span { padding-left: 15px; }
.input-wrap.suffix span { padding-right: 15px; }
.input-wrap input {
    width: 100%;
    min-width: 0;
    padding: 12px 14px;
    border: 0;
    outline: 0;
    background: transparent;
    color: var(--ink);
    font-weight: 600;
}

fieldset { margin: 30px 0 0; padding: 0; border: 0; }
legend { margin-bottom: 10px; }

.segmented {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 4px;
    padding: 4px;
    border-radius: 10px;
    background: var(--surface-muted);
}

.segmented label { position: relative; }
.segmented input { position: absolute; opacity: 0; pointer-events: none; }
.segmented span {
    min-height: 40px;
    display: grid;
    place-items: center;
    border-radius: 7px;
    color: var(--muted);
    cursor: pointer;
    font-size: 13px;
    font-weight: 600;
}
.segmented input:checked + span { background: var(--surface); color: var(--ink); box-shadow: 0 1px 3px rgba(0,0,0,.08); }
.segmented input:focus-visible + span { outline: 3px solid rgba(23, 99, 58, .22); }

.choice-row { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.choice-card {
    min-height: 74px;
    display: flex;
    align-items: flex-start;
    gap: 10px;
    padding: 14px;
    border: 1px solid var(--line);
    border-radius: var(--radius-sm);
    cursor: pointer;
}
.choice-card:has(input:checked) { border-color: var(--accent); background: var(--accent-soft); }
.choice-card input { margin: 4px 0 0; accent-color: var(--accent); }
.choice-card span { display: flex; flex-direction: column; gap: 2px; }
.choice-card strong { font-size: 13px; }

.primary-button {
    width: 100%;
    min-height: 52px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-top: 32px;
    padding: 0 18px;
    border: 0;
    border-radius: var(--radius-sm);
    background: var(--accent);
    color: var(--surface);
    cursor: pointer;
    font-size: 14px;
    font-weight: 700;
    transition: background .16s ease, transform .16s ease;
}
.primary-button:hover { background: var(--accent-hover); }
.primary-button:active { transform: translateY(1px); }
.primary-button:focus-visible { outline: 3px solid rgba(23, 99, 58, .28); outline-offset: 3px; }
.primary-button span { font-size: 19px; }

.results {
    display: flex;
    flex-direction: column;
    background: var(--ink);
    color: var(--surface);
}
.results .step-label { color: #9fcaae; }
.result-kicker { margin: 48px 0 2px; color: #bac5bd; font-size: 13px; }
.payment-amount {
    margin: 0;
    font-family: Georgia, "Times New Roman", serif;
    font-size: clamp(52px, 6vw, 74px);
    letter-spacing: -0.055em;
    line-height: 1.1;
}
.result-caption { max-width: 350px; margin: 12px 0 34px; color: #aebbb2; font-size: 13px; }
.result-details { margin: 0; border-top: 1px solid rgba(255,255,255,.14); }
.result-details div {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
    padding: 14px 0;
    border-bottom: 1px solid rgba(255,255,255,.14);
}
.result-details dt { color: #aebbb2; font-size: 13px; }
.result-details dd { margin: 0; font-size: 14px; font-weight: 650; }
.insight {
    display: flex;
    gap: 12px;
    margin-top: auto;
    padding-top: 34px;
    color: #aebbb2;
}
.insight-icon {
    width: 24px;
    height: 24px;
    flex: 0 0 auto;
    display: grid;
    place-items: center;
    border: 1px solid rgba(255,255,255,.24);
    border-radius: 50%;
    font-family: Georgia, serif;
    font-size: 13px;
}
.insight p { margin: 0; font-size: 12px; }
.insight strong { display: block; margin-bottom: 3px; color: var(--surface); font-size: 13px; }

.result-empty { margin: auto; max-width: 310px; text-align: center; }
.result-empty > span { display: block; margin-bottom: 18px; color: #9fcaae; font-size: 38px; }
.result-empty h2 { margin-bottom: 10px; }
.result-empty p { margin: 0; color: #aebbb2; font-size: 13px; }

.trust-strip {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    padding: 34px 0 72px;
}
.trust-strip > div { display: flex; gap: 14px; }
.trust-strip span { padding-top: 2px; color: var(--accent); font-size: 11px; font-weight: 700; }
.trust-strip p { margin: 0; color: var(--muted); font-size: 12px; }
.trust-strip strong { display: block; margin-bottom: 3px; color: var(--ink); font-size: 13px; }

.guide-section,
.faq-section {
    padding: 76px 0;
    border-top: 1px solid var(--line);
}

.section-heading { max-width: 680px; }
.section-heading h2,
.formula-section h2,
.disclaimer h2 {
    font-family: Georgia, "Times New Roman", serif;
    font-size: clamp(30px, 4vw, 45px);
    font-weight: 400;
    letter-spacing: -0.035em;
    line-height: 1.08;
}
.section-heading > p:last-child,
.formula-section > div > p:last-child { margin: 18px 0 0; color: var(--muted); }
.section-heading.compact { margin-bottom: 30px; }

.guide-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 18px;
    margin-top: 38px;
}
.guide-grid article { min-height: 230px; padding: 26px; border: 1px solid var(--line); border-radius: var(--radius-md); background: var(--surface); }
.article-number { color: var(--accent); font-size: 11px; font-weight: 700; letter-spacing: .1em; }
.guide-grid h3 { margin: 38px 0 10px; font-size: 16px; letter-spacing: -0.015em; }
.guide-grid p { margin: 0; color: var(--muted); font-size: 13px; }

.formula-section {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(320px, .9fr);
    gap: 64px;
    align-items: center;
    padding: 72px 0;
    border-top: 1px solid var(--line);
}
.formula-card { padding: 30px; border-radius: var(--radius-md); background: var(--accent-soft); }
.formula-label { margin: 0; color: var(--accent); font-size: 11px; font-weight: 700; letter-spacing: .1em; text-transform: uppercase; }
.formula { margin: 22px 0 26px; color: var(--ink); font-family: Georgia, "Times New Roman", serif; font-size: 24px; letter-spacing: -0.025em; line-height: 1.25; }
.formula-card dl { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; margin: 0; }
.formula-card dl div { padding-top: 12px; border-top: 1px solid rgba(23,99,58,.18); }
.formula-card dt { color: var(--accent); font-size: 14px; font-weight: 700; }
.formula-card dd { margin: 3px 0 0; color: var(--muted); font-size: 11px; }

.faq-list { max-width: 820px; }
.faq-list details { border-top: 1px solid var(--line); }
.faq-list details:last-child { border-bottom: 1px solid var(--line); }
.faq-list summary { position: relative; padding: 20px 36px 20px 0; cursor: pointer; font-size: 16px; font-weight: 650; list-style: none; }
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list summary::after { content: "+"; position: absolute; right: 4px; color: var(--accent); font-size: 24px; font-weight: 400; line-height: 1; }
.faq-list details[open] summary::after { content: "−"; }
.faq-list summary:focus-visible { outline: 3px solid rgba(23, 99, 58, .22); outline-offset: -3px; }
.faq-list p { max-width: 720px; margin: -2px 0 22px; color: var(--muted); font-size: 14px; }

.disclaimer { margin-bottom: 76px; padding: 28px 32px; border-left: 3px solid var(--accent); background: var(--surface-muted); }
.disclaimer h2 { font-family: inherit; font-size: 16px; font-weight: 700; letter-spacing: 0; }
.disclaimer p { max-width: 860px; margin: 9px 0 0; color: var(--muted); font-size: 13px; }

footer {
    display: flex;
    justify-content: space-between;
    gap: 32px;
    padding: 26px 0 34px;
    border-top: 1px solid var(--line);
    color: var(--muted);
    font-size: 11px;
}
footer p { margin: 0; }

@media (max-width: 840px) {
    .calculator-shell { grid-template-columns: 1fr; }
    .results { min-height: 600px; }
    .trust-strip { grid-template-columns: 1fr; }
    .guide-grid { grid-template-columns: 1fr; }
    .formula-section { grid-template-columns: 1fr; gap: 34px; }
}

@media (max-width: 560px) {
    .site-header, main, footer { width: min(100% - 28px, 1180px); }
    .header-note { display: none; }
    .intro { padding: 48px 0 30px; }
    .intro > p:last-child { font-size: 16px; }
    .calculator-form, .results { padding: 28px 20px; }
    .field-grid, .choice-row { grid-template-columns: 1fr; }
    .field-wide { grid-column: auto; }
    .form-heading { display: block; }
    .secure-note { display: inline-block; margin-top: 12px; }
    .payment-amount { font-size: 50px; }
    .guide-section, .faq-section { padding: 52px 0; }
    .formula-section { padding: 52px 0; }
    .formula-card { padding: 24px 18px; }
    .formula { font-size: 21px; }
    .formula-card dl { grid-template-columns: 1fr; gap: 8px; }
    .disclaimer { margin-bottom: 52px; padding: 22px; }
    footer { flex-direction: column; gap: 10px; }
}