@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Mono:wght@500;600&family=Plus+Jakarta+Sans:wght@400;500;600;700&display=swap');

:root {
  --bg: #f4f5f7;
  --surface: #ffffff;
  --surface-subtle: #f8fafc;
  --surface-muted: #f1f5f9;
  --text: #0f172a;
  --text-secondary: #334155;
  --text-muted: #64748b;
  --border: #cbd5e1;
  --border-light: #e2e8f0;
  --primary: #0f3d3e;
  --primary-hover: #0a292a;
  --primary-subtle: #eef6f6;
  --accent-netto: #0d9488;
  --accent-inps: #d97706;
  --accent-tasse: #dc2626;
  --radius-xs: 4px;
  --radius-sm: 6px;
  --radius-md: 8px;
  --shadow-card: 0 1px 3px rgba(15, 23, 42, 0.05), 0 1px 2px rgba(15, 23, 42, 0.03);
  --font-sans: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: 'IBM Plex Mono', ui-monospace, SFMono-Regular, Menlo, monospace;
}

[data-theme="dark"] {
  --bg: #0b0f17;
  --surface: #111827;
  --surface-subtle: #161f30;
  --surface-muted: #1e293b;
  --text: #f1f5f9;
  --text-secondary: #cbd5e1;
  --text-muted: #94a3b8;
  --border: #334155;
  --border-light: #1e293b;
  --primary: #14b8a6;
  --primary-hover: #2dd4bf;
  --primary-subtle: rgba(20, 184, 166, 0.1);
  --accent-netto: #14b8a6;
  --accent-inps: #f59e0b;
  --accent-tasse: #f87171;
  --shadow-card: 0 2px 6px rgba(0, 0, 0, 0.35);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  font-family: var(--font-sans);
  line-height: 1.5;
  color: var(--text);
  background-color: var(--bg);
  -webkit-font-smoothing: antialiased;
}

body {
  margin: 0;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
}

:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

.container {
  width: min(1180px, 100% - 2.5rem);
  margin-inline: auto;
}

/* Top Institutional Bar & Header */
.top-meta-bar {
  background: #091e26;
  color: #cbd5e1;
  font-size: 0.75rem;
  padding-block: 0.4rem;
  border-block-end: 1px solid rgba(255, 255, 255, 0.08);
}

.top-meta-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.meta-ref {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: #94a3b8;
}

.site-header {
  background: var(--surface);
  border-block-end: 1px solid var(--border-light);
  position: sticky;
  inset-block-start: 0;
  z-index: 30;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding-block: 0.875rem;
}

.brand-link {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  text-decoration: none;
  color: var(--text);
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2rem;
  height: 2rem;
  border-radius: var(--radius-xs);
  background: var(--primary);
  color: #ffffff;
}

[data-theme="dark"] .brand-mark {
  color: #091e26;
}

.brand-text-group {
  display: flex;
  flex-direction: column;
}

.brand-name {
  font-weight: 700;
  font-size: 1.05rem;
  letter-spacing: -0.02em;
  line-height: 1.1;
}

.brand-sub {
  font-size: 0.72rem;
  color: var(--text-muted);
  font-weight: 500;
}

/* Intro & Navigation */
.page-intro {
  padding-block: 1.75rem 1.25rem;
  border-block-end: 1px solid var(--border-light);
  margin-block-end: 1.5rem;
}

h1 {
  font-size: clamp(1.35rem, 2.2vw, 1.75rem);
  font-weight: 700;
  letter-spacing: -0.025em;
  margin: 0 0 0.35rem 0;
  color: var(--text);
}

.intro-lead {
  color: var(--text-secondary);
  font-size: 0.9375rem;
  margin: 0 0 1.25rem 0;
  max-width: 78ch;
}

/* Editorial Segmented Tab Bar */
.tool-tabs {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 0.5rem;
}

.tool-tab-btn {
  width: 100%;
  min-height: 48px;
  border: 1px solid var(--border-light);
  background: var(--surface);
  color: var(--text-secondary);
  font-family: inherit;
  font-size: 0.875rem;
  font-weight: 600;
  padding: 0.65rem 0.9rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  text-align: start;
  transition: border-color 0.15s ease, background-color 0.15s ease, color 0.15s ease;
}

.tool-tab-btn:hover {
  border-color: var(--border);
  background: var(--surface-subtle);
  color: var(--text);
}

.tool-tab-btn[aria-selected="true"] {
  background: var(--primary);
  border-color: var(--primary);
  color: #ffffff;
}

[data-theme="dark"] .tool-tab-btn[aria-selected="true"] {
  color: #091e26;
}

.tab-label-wrap {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.tab-code {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 500;
  opacity: 0.75;
}

/* Main Workspace Grid */
.calculator-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
  align-items: start;
  margin-block-end: 2.5rem;
}

@media (min-width: 920px) {
  .calculator-grid {
    grid-template-columns: 5fr 7fr;
  }
}

.panel {
  background: var(--surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-card);
  overflow: hidden;
}

.panel-header {
  padding: 1rem 1.35rem;
  border-block-end: 1px solid var(--border-light);
  background: var(--surface-subtle);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
}

.panel-header h2 {
  margin: 0;
  font-size: 0.9375rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-secondary);
}

.panel-meta {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
}

.panel-body {
  padding: 1.35rem;
}

/* Forms */
fieldset {
  border: 0;
  padding: 0;
  margin: 0 0 1.35rem 0;
  border-block-end: 1px solid var(--border-light);
  padding-block-end: 1.25rem;
}

fieldset:last-child {
  border-block-end: 0;
  margin-block-end: 0;
  padding-block-end: 0;
}

legend {
  font-weight: 700;
  font-size: 0.8125rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-muted);
  margin-block-end: 0.875rem;
  padding: 0;
}

.form-group {
  margin-block-end: 1.125rem;
}

.form-group:last-child {
  margin-block-end: 0;
}

label {
  display: block;
  font-weight: 600;
  font-size: 0.875rem;
  margin-block-end: 0.35rem;
  color: var(--text);
}

.field-hint {
  display: block;
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-block-start: 0.3rem;
  line-height: 1.4;
}

.input-with-unit {
  position: relative;
  display: flex;
  align-items: center;
}

.input-unit {
  position: absolute;
  inset-inline-end: 0.85rem;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--text-muted);
  pointer-events: none;
}

input[type="text"],
input[type="number"],
select {
  width: 100%;
  font-family: var(--font-sans);
  font-size: 1rem;
  font-variant-numeric: tabular-nums;
  padding: 0.65rem 0.85rem;
  min-height: 48px;
  border-radius: var(--radius-xs);
  border: 1px solid var(--border);
  background-color: var(--surface);
  color: var(--text);
  accent-color: var(--primary);
  transition: border-color 0.15s ease;
}

.input-with-unit input {
  padding-inline-end: 3rem;
  font-family: var(--font-mono);
  font-weight: 500;
}

@media (pointer: coarse) {
  input[type="text"],
  input[type="number"],
  select,
  .btn {
    min-height: 52px;
  }
}

input[type="range"] {
  width: 100%;
  margin-block-start: 0.5rem;
  accent-color: var(--primary);
  cursor: pointer;
}

.radio-pills {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(105px, 1fr));
  gap: 0.45rem;
}

.radio-pill-label {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  min-height: 48px;
  padding: 0.45rem 0.65rem;
  margin: 0;
  border: 1px solid var(--border);
  border-radius: var(--radius-xs);
  background: var(--surface);
  cursor: pointer;
  font-weight: 600;
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.radio-pill-label:has(input:checked) {
  border-color: var(--primary);
  background: var(--primary-subtle);
  color: var(--primary);
}

.radio-pill-label input[type="radio"] {
  accent-color: var(--primary);
  margin: 0;
}

/* Accounting Results Area */
.summary-strip {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
  padding: 1.25rem;
  background: var(--surface-subtle);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  margin-block-end: 1.25rem;
}

@media (min-width: 560px) {
  .summary-strip {
    grid-template-columns: 1.2fr 1fr;
    align-items: center;
  }
}

.primary-figure-label {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
}

.primary-figure-value {
  font-family: var(--font-mono);
  font-size: clamp(1.75rem, 3vw, 2.25rem);
  font-weight: 600;
  color: var(--text);
  line-height: 1.2;
  margin-block: 0.2rem;
  font-variant-numeric: tabular-nums;
}

.primary-figure-sub {
  font-size: 0.82rem;
  color: var(--text-secondary);
}

.secondary-figures {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
  border-inline-start: 1px solid var(--border-light);
  padding-inline-start: 1rem;
}

@media (max-width: 559px) {
  .secondary-figures {
    border-inline-start: 0;
    border-block-start: 1px solid var(--border-light);
    padding-inline-start: 0;
    padding-block-start: 0.75rem;
  }
}

.mini-stat-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  display: block;
}

.mini-stat-val {
  font-family: var(--font-mono);
  font-size: 0.98rem;
  font-weight: 600;
  color: var(--text);
  font-variant-numeric: tabular-nums;
}

/* Stacked Distribution Bar + Legend */
.distribution-wrap {
  margin-block-end: 1.35rem;
}

.distribution-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  font-size: 0.78rem;
  color: var(--text-secondary);
  margin-block-end: 0.45rem;
}

.legend-item {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}

.legend-dot {
  width: 8px;
  height: 8px;
  border-radius: 2px;
}

.dot-netto { background: var(--accent-netto); }
.dot-inps { background: var(--accent-inps); }
.dot-tasse { background: var(--accent-tasse); }

.breakdown-bar {
  height: 8px;
  border-radius: 2px;
  background: var(--surface-muted);
  overflow: hidden;
  display: flex;
}

.bar-segment {
  height: 100%;
  transition: width 0.25s ease;
}

.bar-netto { background: var(--accent-netto); }
.bar-inps { background: var(--accent-inps); }
.bar-tasse { background: var(--accent-tasse); }

/* Analytical Accounting Table (Prospetto Contabile) */
.accounting-table-wrap {
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  overflow-x: auto;
  margin-block-end: 1.25rem;
}

.accounting-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.85rem;
  text-align: start;
}

.accounting-table th,
.accounting-table td {
  padding: 0.65rem 0.85rem;
  border-block-end: 1px solid var(--border-light);
}

.accounting-table th {
  background: var(--surface-subtle);
  font-size: 0.73rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-muted);
}

.accounting-table td.num,
.accounting-table th.num {
  text-align: end;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
}

.accounting-table tr:last-child td {
  border-block-end: 0;
  font-weight: 700;
  background: var(--surface-subtle);
}

/* Resource / Spreadsheet Download Box */
.resource-box {
  background: var(--surface-subtle);
  border: 1px solid var(--border);
  border-inline-start: 3px solid var(--primary);
  border-radius: var(--radius-xs);
  padding: 1rem 1.15rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.resource-info {
  flex: 1 1 280px;
}

.resource-kicker {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--primary);
  font-weight: 600;
  display: block;
  margin-block-end: 0.15rem;
}

.resource-title {
  font-size: 0.92rem;
  font-weight: 700;
  margin: 0 0 0.2rem 0;
  color: var(--text);
}

.resource-desc {
  font-size: 0.8125rem;
  color: var(--text-secondary);
  margin: 0;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  min-height: 44px;
  padding: 0.55rem 1rem;
  border-radius: var(--radius-xs);
  font-family: inherit;
  font-size: 0.85rem;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  border: 1px solid transparent;
  transition: background-color 0.15s ease, border-color 0.15s ease;
}

.btn-primary {
  background: var(--primary);
  color: #ffffff;
}

[data-theme="dark"] .btn-primary {
  color: #091e26;
}

.btn-primary:hover {
  background: var(--primary-hover);
}

.btn-outline {
  background: var(--surface);
  color: var(--text-secondary);
  border-color: var(--border);
}

.btn-outline:hover {
  background: var(--surface-subtle);
  color: var(--text);
}

.btn-sm {
  min-height: 36px;
  padding: 0.35rem 0.7rem;
  font-size: 0.8rem;
}

.panel-footer-actions {
  display: flex;
  justify-content: flex-end;
  margin-block-top: 1rem;
}

/* Editorial Methodology & FAQ Section */
.faq-section {
  margin-block: 1rem 3rem;
  border-block-start: 1px solid var(--border-light);
  padding-block-start: 2rem;
}

.faq-section h2 {
  font-size: 1.15rem;
  margin: 0 0 1rem 0;
}

details {
  background: var(--surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-xs);
  margin-block-end: 0.5rem;
  padding: 0 1.1rem;
}

summary {
  font-weight: 600;
  font-size: 0.92rem;
  padding-block: 0.85rem;
  cursor: pointer;
  color: var(--text);
}

details[open] summary {
  border-block-end: 1px solid var(--border-light);
  margin-block-end: 0.75rem;
}

details p {
  margin-block: 0 0.95rem;
  color: var(--text-secondary);
  font-size: 0.875rem;
  line-height: 1.6;
}

/* Footer */
.site-footer {
  margin-block-start: auto;
  background: var(--surface);
  border-block-start: 1px solid var(--border-light);
  padding-block: 1.5rem;
  color: var(--text-muted);
  font-size: 0.8rem;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

@media print {
  .top-meta-bar,
  .site-header,
  .page-intro,
  .resource-box,
  .panel-footer-actions,
  .faq-section,
  .site-footer {
    display: none !important;
  }
  .calculator-grid {
    grid-template-columns: 1fr 1fr;
  }
}