/* 1. Designvariablen: helles Erscheinungsbild und gemeinsame Größen. */
:root {
  color-scheme: light;
  --page: #f6f8f7;
  --surface: #ffffff;
  --soft: #edf3ef;
  --text: #1b3028;
  --muted: #53665b;
  --border: #d4dfd8;
  --control-border: #7a8c80;
  --accent: #286044;
  --accent-soft: #e1eee5;
  --focus: #246bdb;
  --result: #eaf2ed;
  --result-top: #deece2;
  --shadow: 0 4px 24px #17372705;
  --radius: 1.125rem;
  --content-width: 74rem;
}

/* 2. Dunkles Erscheinungsbild: System ohne manuelle Auswahl. */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) {
    color-scheme: dark;
    --page: #111b17;
    --surface: #19261f;
    --soft: #24352b;
    --text: #edf4ef;
    --muted: #b2c3b8;
    --border: #3b5143;
    --control-border: #7d9786;
    --accent: #a0d7b3;
    --accent-soft: #2a4333;
    --focus: #9bc2ff;
    --result: #1d3025;
    --result-top: #253e2e;
    --shadow: 0 4px 24px #0000000d;
  }
}

/* Explizite Auswahl hat Vorrang vor dem System. Hell nutzt die Wurzelwerte. */
:root[data-theme="dark"] {
  color-scheme: dark;
  --page: #111b17;
  --surface: #19261f;
  --soft: #24352b;
  --text: #edf4ef;
  --muted: #b2c3b8;
  --border: #3b5143;
  --control-border: #7d9786;
  --accent: #a0d7b3;
  --accent-soft: #2a4333;
  --focus: #9bc2ff;
  --result: #1d3025;
  --result-top: #253e2e;
  --shadow: 0 4px 24px #0000000d;
}

/* 3. Grundelemente und Typografie. Keine Animationen oder Farbtransitionen. */
* { box-sizing: border-box; }
[hidden] { display: none !important; }
html { background: var(--page); color: var(--text); font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; line-height: 1.65; font-synthesis: none; }
body { margin: 0; }
h1, h2, h3, h4, p { margin: 0; }
h1, h2, h3, h4 { text-wrap: balance; }
h1 { max-width: 22ch; font-size: clamp(2rem, 4.4vw, 3.6rem); line-height: 1.1; letter-spacing: -.045em; font-weight: 750; }
h2 { font-size: clamp(1.4rem, 2.5vw, 1.85rem); line-height: 1.3; letter-spacing: -.025em; }
h3 { font-size: 1.15rem; line-height: 1.4; letter-spacing: -.015em; }
h4 { font-size: .94rem; line-height: 1.4; font-weight: 650; }
a { color: var(--accent); text-underline-offset: .2em; }
:focus-visible { outline: 3px solid var(--focus); outline-offset: 4px; }
main:focus-visible { outline: 3px solid var(--focus); outline-offset: 4px; }

/* 4. Layout: ein gemeinsamer Lesefluss für alle Geräte. */
.container { width: min(calc(100% - 2rem), var(--content-width)); margin-inline: auto; }
.header-content { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 1rem; padding-block: 1.1rem; }
.identity { display: flex; flex-wrap: wrap; align-items: baseline; gap: .15rem 1.25rem; }
.intro { padding-block: 2.5rem 2rem; max-width: 53rem; }
.intro-meta { display: flex; flex-wrap: wrap; align-items: center; gap: .75rem 1.25rem; margin-bottom: 1.5rem; }
.calculator-section { padding-block: 2rem 2.5rem; }
.section-heading { display: flex; flex-wrap: wrap; align-items: flex-end; justify-content: space-between; gap: .75rem 1.5rem; margin-bottom: 1.5rem; }
.section-heading .eyebrow { margin-bottom: .35rem; }
.calculator-layout, .input-cards { display: grid; gap: 1rem; align-items: start; }
.calculator-layout > *, .card-content, .method > * { min-width: 0; }
.method { display: grid; gap: 1.25rem; border-top: 1px solid var(--border); padding-block: 2rem 3rem; }
.method .eyebrow { margin-bottom: .5rem; }
.method-content { color: var(--muted); max-width: 65ch; }
.method-content p + p { margin-top: .75rem; }

/* 5. Komponenten. */
.skip-link { position: absolute; top: .75rem; left: 1rem; padding: .75rem 1rem; z-index: 2; background: var(--surface); transform: translateY(-200%); border: 1px solid var(--control-border); border-radius: .4rem; }
.skip-link:focus { transform: none; }
.site-header { background: var(--surface); border-bottom: 1px solid var(--border); }
.brand { font-size: 1.75rem; font-weight: 800; letter-spacing: -.065em; line-height: 1.2; }
.brand span { color: var(--accent); }
.project-label { color: var(--muted); font-size: .85rem; }
.theme-control { display: flex; flex-wrap: wrap; align-items: center; gap: .5rem .75rem; }
.theme-control label { font-size: .8rem; color: var(--muted); }
.theme-control select { min-height: 44px; padding: .5rem .6rem; border: 1px solid var(--control-border); border-radius: .5rem; background: var(--surface); color: var(--text); font: inherit; font-size: .9rem; cursor: pointer; }
.eyebrow { color: var(--accent); font-size: .75rem; font-weight: 700; letter-spacing: .085em; text-transform: uppercase; }
.status { display: inline-flex; align-items: center; gap: .4rem; border: 1px solid var(--border); border-radius: 2rem; padding: .2rem .7rem; color: var(--muted); background: var(--surface); font-size: .75rem; font-weight: 600; }
.status::before { content: ""; width: .4rem; height: .4rem; background: var(--accent); border-radius: 50%; }
.lead { max-width: 62ch; margin-top: 1.25rem; font-size: clamp(1rem, 1.6vw, 1.15rem); color: var(--muted); }
.benefits { display: flex; flex-wrap: wrap; gap: .5rem 1.5rem; margin: 1.5rem 0 0; padding: 0; list-style: none; font-size: .85rem; font-weight: 550; }
.benefits li::before { content: "✓"; margin-right: .5rem; color: var(--accent); }
.development-note { display: flex; gap: .85rem; align-items: flex-start; background: var(--soft); border: 1px solid var(--border); border-radius: .65rem; padding: 1rem 1.15rem; font-size: .875rem; color: var(--muted); }
.development-note strong { color: var(--text); font-weight: 650; }
.note-mark { flex: 0 0 1.25rem; display: grid; place-items: center; height: 1.25rem; margin-top: .1rem; border: 1px solid var(--accent); border-radius: 50%; color: var(--accent); font-size: .75rem; font-weight: 700; }
noscript .development-note { margin-top: 1rem; }
.section-caption { font-size: .75rem; color: var(--muted); }
.planning-card { display: flex; align-items: flex-start; gap: 1rem; padding: 1.25rem; border: 1px solid var(--border); border-radius: var(--radius); background: var(--surface); box-shadow: var(--shadow); }
.step-number { flex: 0 0 2.25rem; width: 2.25rem; height: 2.25rem; display: grid; place-items: center; border-radius: .7rem; background: var(--accent-soft); color: var(--accent); font-size: .8rem; font-weight: 700; font-variant-numeric: tabular-nums; }
.planning-card p { margin-top: .5rem; color: var(--muted); font-size: .925rem; }
.card-caption { display: block; border-top: 1px solid var(--border); margin-top: 1rem; padding-top: .75rem; font-size: .75rem; color: var(--muted); }
.results-card { border: 1px solid var(--border); border-radius: var(--radius); background: var(--result); overflow-wrap: anywhere; }
.results-header { padding: 1.5rem; background: var(--result-top); border-radius: var(--radius) var(--radius) 0 0; }
.results-header h3 { margin-top: .45rem; font-size: 1.35rem; }
.results-header > p:last-child { margin-top: .75rem; font-size: .875rem; color: var(--muted); }
.result-types { list-style: none; margin: 0; padding: .25rem 1.5rem; }
.result-types li { display: flex; align-items: flex-start; gap: .7rem; padding-block: 1rem; }
.result-types li + li { border-top: 1px solid var(--border); }
.result-types p { font-size: .8rem; color: var(--muted); margin-top: .2rem; }
.result-dot { flex: 0 0 .4rem; height: .4rem; margin-top: .45rem; background: var(--accent); border-radius: 50%; }
.results-footnote { padding: .5rem 1.5rem 1.25rem; font-size: .75rem; color: var(--muted); }
.site-footer { border-top: 1px solid var(--border); }
.footer-content { display: flex; flex-wrap: wrap; justify-content: space-between; gap: .75rem 2rem; padding-block: 1.5rem; color: var(--muted); font-size: .75rem; }
.footer-content strong { color: var(--text); font-size: 1rem; letter-spacing: -.04em; margin-right: .75rem; }
.footer-content p:first-child { display: flex; flex-wrap: wrap; align-items: baseline; gap: .25rem; }
.footer-links { display: flex; flex-wrap: wrap; gap: .25rem 1.25rem; min-width: 0; }
.footer-links a { display: inline-flex; align-items: center; min-height: 44px; overflow-wrap: anywhere; }

/* 6. Responsive Anpassungen: Tablet ab 44rem, zwei Bereiche ab 62rem. */
@media (min-width: 44rem) {
  .container { width: min(calc(100% - 4rem), var(--content-width)); }
  .intro { padding-block: 3.5rem 2.25rem; }
  .planning-card { padding: 1.5rem; }
  .method { grid-template-columns: 1fr 1.3fr; gap: 3rem; padding-block: 2.5rem 3.5rem; }
}
@media (min-width: 62rem) {
  .calculator-layout { grid-template-columns: minmax(0, 1.45fr) minmax(0, 1fr); gap: 1.5rem; }
  .intro { padding-top: 4rem; }
}
/* Schmale Karten bleiben ohne seitliche Nummernspalte besser lesbar. */
@media (max-width: 23rem) {
  .planning-card { flex-direction: column; }
  .theme-control { width: 100%; justify-content: space-between; }
  .theme-control select { min-width: 7rem; }
}
@media (forced-colors: active) {
  .status, .planning-card, .results-card, .development-note { border-color: CanvasText; }
  .result-dot, .status::before { background: CanvasText; }
}


/* 7. Phase 3: zugängliche Formulare und flexible Meldungen. */
:root { --error: #a12a24; --warning: #795100; --error-surface: #fff3f1; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) { --error: #ffb3aa; --warning: #efcf81; --error-surface: #362622; }
}
:root[data-theme="dark"] { --error: #ffb3aa; --warning: #efcf81; --error-surface: #362622; }
#planning-form { display: grid; gap: 1.25rem; min-width: 0; }
.form-intro { color: var(--muted); font-size: .875rem; }
.form-card { display: block; min-inline-size: 0; margin: 0; padding: 1.25rem; }
.form-card legend { display: flex; align-items: center; gap: .75rem; padding-inline: .25rem; font-size: 1.1rem; line-height: 1.4; font-weight: 700; max-width: 100%; }
.form-card legend .step-number { flex-shrink: 0; }
.field-grid { display: grid; gap: 1.5rem; padding-top: .5rem; }
.form-field { min-width: 0; }
.form-field > label { display: block; font-size: .925rem; line-height: 1.5; font-weight: 650; margin-bottom: .5rem; }
.field-requirement { color: var(--muted); font-size: .75rem; font-weight: 400; }
.amount-row { display: grid; grid-template-columns: minmax(0, 1fr); gap: .65rem; align-items: end; }
.input-wrap { position: relative; min-width: 0; }
.form-field input, .form-field select { display: block; min-width: 0; width: 100%; min-height: 48px; border: 1px solid var(--control-border); border-radius: .5rem; color: var(--text); background: var(--surface); font: inherit; padding: .65rem .75rem; }
.form-field input { padding-right: 3.5rem; font-variant-numeric: tabular-nums; }
.form-field input[aria-invalid="true"] { border: 2px solid var(--error); }
.input-unit { position: absolute; top: 50%; right: .75rem; transform: translateY(-50%); color: var(--muted); pointer-events: none; font-size: .8rem; }
.period-control label { display: block; font-size: .75rem; color: var(--muted); margin-bottom: .25rem; }
.planning-card .field-help, .planning-card .field-error, .planning-card .field-warning { font-size: .8rem; margin-top: .5rem; }
.planning-card .field-error { color: var(--error); font-weight: 550; }
.planning-card .field-warning { color: var(--warning); }
.error-summary { border: 2px solid var(--error); border-radius: .75rem; background: var(--error-surface); padding: 1.1rem; overflow-wrap: anywhere; }
.error-summary h3, .error-summary a { color: var(--error); }
.error-summary p, .error-summary ul { font-size: .875rem; margin-top: .65rem; }
.error-summary ul { padding-left: 1.25rem; margin-bottom: 0; }
.error-summary li + li { margin-top: .6rem; }
.error-summary a { display: inline-block; padding-block: .2rem; }
.form-actions { display: grid; gap: .75rem; }
.primary-button { min-height: 48px; border: 1px solid var(--accent); border-radius: .6rem; padding: .75rem 1.25rem; background: var(--accent); color: var(--surface); font: inherit; font-weight: 650; cursor: pointer; }
.primary-button:hover { text-decoration: underline; text-underline-offset: .2em; }
.form-actions p { font-size: .8rem; color: var(--muted); }
#form-status:not(:empty) { border-left: 3px solid var(--accent); border-radius: .25rem; padding: 1rem; background: var(--soft); color: var(--text); font-size: .9rem; }
#form-status.is-success { font-weight: 600; }
@media (min-width: 30rem) {
  .amount-row { grid-template-columns: minmax(0, 1fr) minmax(8rem, .65fr); }
  .form-card { padding: 1.5rem; }
  .primary-button { justify-self: start; }
}
@media (forced-colors: active) {
  .form-field input[aria-invalid="true"], .error-summary { border-color: CanvasText; }
}

/* 8. Ergebniszustände: vollständig fließend, ohne verdeckende feste Flächen. */
.results-navigation { margin-bottom: 1rem; }
.results-jump { display: inline-flex; align-items: center; gap: .75rem; min-height: 44px; font-size: .9rem; font-weight: 650; }
#ergebnis { scroll-margin-top: 1rem; min-width: 0; }
.results-placeholder { padding: 1.5rem; color: var(--muted); font-size: .9rem; }
.results-content { padding: 1.25rem; }
.rate-list, .metric-list { padding: 0; margin: 0; }
.rate-list > div { padding: 1rem; background: var(--surface); border: 1px solid var(--border); border-radius: .75rem; }
.rate-list > div + div { margin-top: .75rem; background: var(--result-top); }
.rate-list dt { font-weight: 650; font-size: .9rem; line-height: 1.45; }
.rate-list dd { margin: .5rem 0 0; }
.rate-list dd > .result-value { font-size: clamp(1.6rem, 2.6vw, 2.15rem); line-height: 1.25; letter-spacing: -.025em; }
.result-value { display: block; font-weight: 700; font-variant-numeric: tabular-nums; overflow-wrap: anywhere; }
.metric-hint, .metric-caption { color: var(--muted); font-size: .8rem; margin-top: .5rem; }
.result-section { margin-top: 1.5rem; }
.result-section > h4 { margin-bottom: .25rem; font-size: 1rem; }
.metric-list > div { display: grid; gap: .25rem .75rem; padding-block: .85rem; }
.metric-list > div + div { border-top: 1px solid var(--border); }
.metric-list dt { font-size: .85rem; color: var(--muted); }
.metric-list dd { margin: 0; min-width: 0; font-size: .95rem; }
.result-details { border-top: 1px solid var(--border); margin-top: 1rem; padding-top: .5rem; }
.result-details > summary, .number-detail > summary { min-height: 44px; align-content: center; padding-block: .65rem; cursor: pointer; color: var(--accent); font-weight: 650; font-size: .875rem; }
#calculation-steps { padding-left: 1.3rem; margin-block: .75rem; font-size: .85rem; }
#calculation-steps li { padding-left: .25rem; }
#calculation-steps li + li { margin-top: 1rem; }
#calculation-steps p { margin-top: .35rem; color: var(--muted); }
.result-notes { margin-top: 1.25rem; border-top: 1px solid var(--border); padding-top: 1rem; font-size: .775rem; color: var(--muted); }
.result-notes p + p { margin-top: .75rem; }
.result-warnings { font-size: .8rem; color: var(--warning); }
.result-warnings ul { padding-left: 1.1rem; margin-bottom: 0; }
.result-warnings li + li { margin-top: .5rem; }
.precision-note { font-size: .8rem; margin-top: 1rem; color: var(--muted); }
.number-detail { margin-top: .35rem; font-size: .75rem; font-weight: 400; }
.number-detail > summary { font-size: .75rem; font-weight: 500; }
.number-detail > p { overflow-wrap: anywhere; color: var(--muted); margin-block: .3rem; font-variant-numeric: tabular-nums; }
@media (min-width: 30rem) {
  .metric-list > div { grid-template-columns: minmax(0, 1.1fr) minmax(0, 1fr); align-items: baseline; }
}
.print-only { display: none; }
.utility-actions { display: grid; gap: 1rem; margin-block: 1.25rem; }
.utility-actions > div { min-width: 0; }
.utility-actions p, .print-actions p { font-size: .85rem; color: var(--muted); margin-top: .5rem; }
.secondary-button { min-height: 48px; max-width: 100%; padding: .7rem 1rem; border: 1px solid var(--control-border); border-radius: .65rem; background: var(--surface); color: var(--text); font: inherit; font-weight: 600; cursor: pointer; overflow-wrap: anywhere; }
.secondary-button:hover { background: var(--accent-soft); }
.secondary-button:focus-visible { outline: 3px solid var(--focus); outline-offset: 3px; }
.example-origin { padding: .85rem; border: 1px solid var(--border); border-radius: .65rem; background: var(--accent-soft); }
.print-actions { padding: 1rem; border-bottom: 1px solid var(--border); }
@media (min-width: 44rem) { .utility-actions { grid-template-columns: repeat(2, minmax(0, 1fr)); } }

/* Statische Anleitung: eigener Lesefluss unterhalb des Rechners. */
.guide { max-width: 76ch; margin-inline: auto; padding-bottom: 2rem; overflow-wrap: anywhere; }
.guide-nav { border-block: 1px solid var(--border); padding-block: .75rem; }
.guide-nav ul { display: flex; flex-wrap: wrap; gap: .25rem 1.25rem; list-style: none; padding: 0; margin: 0; }
.guide-nav a { display: inline-flex; align-items: center; min-height: 44px; }
.guide-section { padding-block: 2rem; }
.guide-section + .guide-section { border-top: 1px solid var(--border); }
.guide-section h2, .guide-section h3 { scroll-margin-top: 1rem; }
.guide-section h2 { margin-bottom: 1rem; }
.guide-section h3 { margin-block: 1.5rem .65rem; }
.guide-section p + p { margin-top: .85rem; }
.guide-section ol, .guide-section ul { padding-left: 1.4rem; margin-block: 1rem; }
.guide-section li + li { margin-top: .7rem; }
.guide-definitions, .example-values { margin-block: 1.25rem; }
.guide-definitions > div, .example-values > div { min-width: 0; border-bottom: 1px solid var(--border); padding-block: .75rem; }
.guide-section dt { font-weight: 650; }
.guide-section dd { min-width: 0; margin: .25rem 0 0; }
.formula-block { padding: 1rem; margin-block: 1.25rem; border: 1px solid var(--border); border-radius: var(--radius); background: var(--soft); }
.example-results { padding: .25rem 1rem; border: 1px solid var(--border); border-radius: var(--radius); background: var(--result); }
.example-results > div:last-child { border-bottom: 0; }
.example-values dd { font-variant-numeric: tabular-nums; }
.faq details { border-bottom: 1px solid var(--border); }
.faq summary { min-height: 44px; padding-block: .85rem; cursor: pointer; color: var(--text); font-weight: 650; }
.faq details p { padding-bottom: 1rem; }
@media (min-width: 44rem) {
  .example-values > div { display: grid; grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr); gap: 1rem; }
  .example-values dd { margin: 0; }
}