/* ==========================================================================
   Gravel & Landscape Material Calculators — Production Stylesheet
   Architecture: Clean Static CSS3 | Mobile-First | Print-Ready | WCAG AA
   ========================================================================== */

:root {
  /* 60% Dominant Neutral Canvas (Warm Quarry Stone Neutral) */
  --bg-canvas: #f7f6f2;
  --bg-surface: #ffffff;
  --bg-subtle: #efede7;
  --bg-muted: #e5e2d9;

  /* 30% Structural Surfaces & High-Contrast Typography */
  --text-primary: #14171a;
  --text-secondary: #384047;
  --text-muted: #5c6670;
  --border-color: #d5d1c8;
  --border-strong: #9e988c;
  --panel-dark: #181c20;
  --panel-dark-elevated: #22282e;
  --panel-dark-border: #333b44;
  --panel-dark-text: #f9fafb;
  --panel-dark-muted: #cbd5e1;

  /* 10% Accent Budget (Contractor Safety Amber & Field Green) */
  --accent-primary: #b45309;
  --accent-primary-hover: #92400e;
  --accent-bright: #f59e0b;
  --accent-tint: #fef3c7;
  --accent-border: #f59e0b;

  --status-success: #15803d;
  --status-success-bg: #f0fdf4;
  --status-success-border: #86efac;

  --status-error: #b91c1c;
  --status-error-bg: #fef2f2;
  --status-error-border: #fca5a5;

  --status-info-bg: #f8fafc;
  --status-info-border: #cbd5e1;

  /* Typography */
  --font-sans: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;

  /* Layout & Spacing */
  --container-max: 1200px;
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --shadow-card: 0 1px 3px rgba(20, 23, 26, 0.06);
}

/* Reset & Base */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.65;
  color: var(--text-primary);
  background-color: var(--bg-canvas);
  -webkit-font-smoothing: antialiased;
}

/* Focus Accessibility */
:focus-visible {
  outline: 3px solid var(--accent-bright);
  outline-offset: 2px;
}

/* Skip Link */
.skip-link {
  position: absolute;
  top: -100px;
  left: 1rem;
  z-index: 1000;
  padding: 0.75rem 1.25rem;
  background: var(--panel-dark);
  color: #ffffff;
  font-weight: 600;
  text-decoration: none;
  border-radius: var(--radius-md);
}

.skip-link:focus {
  top: 0.75rem;
}

/* Typography Rules */
h1, h2, h3, h4 {
  margin-top: 0;
  color: var(--text-primary);
  font-weight: 700;
  line-height: 1.22;
  letter-spacing: -0.02em;
  text-wrap: balance;
}

h1 {
  font-size: clamp(1.75rem, 3.2vw, 2.5rem);
  margin-bottom: 0.75rem;
}

h2 {
  font-size: clamp(1.35rem, 2.2vw, 1.75rem);
  margin-bottom: 0.85rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border-color);
}

h3 {
  font-size: clamp(1.125rem, 1.6vw, 1.3rem);
  margin-bottom: 0.5rem;
}

p {
  margin-top: 0;
  margin-bottom: 1.15rem;
  max-width: 72ch;
  color: var(--text-secondary);
}

a {
  color: var(--accent-primary);
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: color 150ms ease;
}

a:hover {
  color: var(--accent-primary-hover);
}

.tabular-nums {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
}

/* Container */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 1.25rem;
}

@media (min-width: 768px) {
  .container {
    padding: 0 2rem;
  }
}

/* ==========================================================================
   Top Bar Contract (3-Zone Header, <15% Mobile Viewport Height)
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background-color: var(--bg-surface);
  border-bottom: 1px solid var(--border-color);
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 60px;
  gap: 1rem;
}

/* Zone 1: Single text element Brand Wordmark */
.site-brand {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-primary);
  text-decoration: none;
  letter-spacing: -0.02em;
  white-space: nowrap;
  padding: 0.35rem 0;
}

.site-logo {
  height: 40px;
  width: auto;
  max-width: 260px;
  display: block;
}

@media (max-width: 480px) {
  .site-logo {
    height: 34px;
    max-width: 210px;
  }
}

.site-brand:hover {
  opacity: 0.92;
}

.diagram-container {
  margin: 1.75rem 0;
  text-align: center;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1rem;
  overflow: hidden;
}

.diagram-img {
  max-width: 100%;
  height: auto;
  display: inline-block;
  vertical-align: middle;
  border-radius: var(--radius-sm);
}

.diagram-caption {
  margin-top: 0.75rem;
  font-size: 0.85rem;
  color: var(--text-muted);
  font-weight: 500;
}

/* Zone 2: Clean Typography Nav Links */
.site-nav {
  display: none;
  align-items: center;
  gap: 1.5rem;
}

@media (min-width: 960px) {
  .site-nav {
    display: flex;
  }
}

.site-nav__link {
  font-size: 0.925rem;
  font-weight: 600;
  color: var(--text-secondary);
  text-decoration: none;
  padding: 0.5rem 0;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  white-space: nowrap;
  border-bottom: 2px solid transparent;
}

.site-nav__link:hover,
.site-nav__link[aria-current="page"] {
  color: var(--text-primary);
  border-bottom-color: var(--accent-primary);
}

/* Zone 3: Primary Action & Mobile Trigger */
.site-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.btn-header-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 40px;
  padding: 0.45rem 0.95rem;
  font-size: 0.875rem;
  font-weight: 600;
  color: #ffffff;
  background-color: var(--panel-dark);
  border-radius: var(--radius-md);
  text-decoration: none;
  white-space: nowrap;
  transition: background-color 150ms ease;
}

.btn-header-cta:hover {
  background-color: var(--accent-primary);
  color: #ffffff;
}

.mobile-menu-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 44px;
  min-height: 44px;
  padding: 0.5rem;
  background: transparent;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-size: 0.875rem;
  font-weight: 600;
  cursor: pointer;
}

@media (min-width: 960px) {
  .mobile-menu-toggle {
    display: none;
  }
}

.mobile-drawer {
  display: none;
  background: var(--bg-surface);
  border-bottom: 2px solid var(--border-color);
  padding: 1rem 1.25rem 1.5rem;
}

.mobile-drawer.is-open {
  display: block;
}

.mobile-drawer__grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 0.5rem;
}

.mobile-drawer__link {
  display: flex;
  align-items: center;
  min-height: 44px;
  padding: 0.5rem 0.75rem;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
  text-decoration: none;
  border-radius: var(--radius-sm);
  background: var(--bg-canvas);
}

.mobile-drawer__link:hover,
.mobile-drawer__link[aria-current="page"] {
  background: var(--accent-tint);
  color: var(--accent-primary-hover);
}

/* ==========================================================================
   Breadcrumbs
   ========================================================================== */
.breadcrumbs {
  padding: 0.85rem 0 0.25rem;
  font-size: 0.875rem;
  color: var(--text-muted);
}

.breadcrumbs__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.45rem;
}

.breadcrumbs__item {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
}

.breadcrumbs__link {
  color: var(--text-secondary);
  text-decoration: none;
  font-weight: 500;
}

.breadcrumbs__link:hover {
  color: var(--accent-primary);
  text-decoration: underline;
}

.breadcrumbs__sep {
  color: var(--text-muted);
  user-select: none;
}

.breadcrumbs__current {
  color: var(--text-primary);
  font-weight: 600;
}

/* ==========================================================================
   Page Hero & Intro
   ========================================================================== */
.page-hero {
  padding: 1.5rem 0 1.25rem;
}

.page-hero__kicker {
  font-size: 0.825rem;
  font-weight: 600;
  color: var(--text-muted);
  margin-bottom: 0.4rem;
}

.page-hero__lead {
  font-size: 1.075rem;
  color: var(--text-secondary);
  max-width: 75ch;
  margin-bottom: 0.5rem;
}

.page-hero__meta {
  font-size: 0.85rem;
  color: var(--text-muted);
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  align-items: center;
}

/* ==========================================================================
   Core Calculator Workbench Layout
   ========================================================================== */
.calculator-section {
  margin: 1rem 0 2.75rem;
}

.calculator-workbench {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
  align-items: start;
}

@media (min-width: 960px) {
  .calculator-workbench {
    grid-template-columns: 7fr 5fr;
    gap: 1.75rem;
  }
}

/* Left Column: Input Form Card */
.calc-form-panel {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.25rem;
  box-shadow: var(--shadow-card);
}

@media (min-width: 640px) {
  .calc-form-panel {
    padding: 1.75rem;
  }
}

.calc-panel-header {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.5rem;
  padding-bottom: 1rem;
  margin-bottom: 1.25rem;
  border-bottom: 1px solid var(--border-color);
}

.calc-panel-title {
  font-size: 1.15rem;
  font-weight: 700;
  margin: 0;
}

.calc-panel-subtitle {
  font-size: 0.825rem;
  color: var(--text-muted);
}

/* Mode Switcher (Dimensions vs Direct Volume) */
.calc-mode-tabs {
  display: flex;
  gap: 0.35rem;
  padding: 0.3rem;
  background: var(--bg-subtle);
  border-radius: var(--radius-md);
  margin-bottom: 1.25rem;
}

.calc-mode-tab {
  flex: 1;
  min-height: 44px;
  padding: 0.5rem 0.75rem;
  border: none;
  border-radius: var(--radius-sm);
  background: transparent;
  color: var(--text-secondary);
  font-family: var(--font-sans);
  font-size: 0.875rem;
  font-weight: 600;
  cursor: pointer;
  white-space: nowrap;
  transition: background-color 150ms ease, color 150ms ease;
}

.calc-mode-tab[aria-selected="true"] {
  background: var(--bg-surface);
  color: var(--text-primary);
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.08);
}

/* Quick Presets Bar */
.calc-presets {
  margin-bottom: 1.25rem;
}

.calc-presets__label {
  display: block;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-muted);
  margin-bottom: 0.45rem;
}

.calc-presets__list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
}

.btn-preset {
  min-height: 40px;
  padding: 0.4rem 0.75rem;
  font-family: var(--font-sans);
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--text-secondary);
  background: var(--bg-canvas);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  cursor: pointer;
  white-space: nowrap;
  transition: border-color 150ms ease, background-color 150ms ease;
}

.btn-preset:hover {
  border-color: var(--accent-primary);
  background: var(--accent-tint);
  color: var(--text-primary);
}

.btn-preset.is-active {
  background: var(--panel-dark);
  color: #ffffff;
  border-color: var(--panel-dark);
}

/* Form Field Groups */
.calc-field-group {
  margin-bottom: 1.15rem;
}

.calc-label-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.5rem;
  margin-bottom: 0.35rem;
}

.calc-label {
  font-size: 0.925rem;
  font-weight: 700;
  color: var(--text-primary);
}

.calc-hint {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* Input + Unit Combo Row */
.calc-input-row {
  display: grid;
  grid-template-columns: 1fr 130px;
  gap: 0.5rem;
}

@media (min-width: 480px) {
  .calc-input-row {
    grid-template-columns: 1fr 150px;
  }
}

.calc-input,
.calc-select {
  width: 100%;
  min-height: 48px;
  padding: 0.625rem 0.85rem;
  font-family: var(--font-mono);
  font-size: 1rem;
  font-weight: 500;
  color: var(--text-primary);
  background-color: var(--bg-surface);
  border: 1.5px solid var(--border-strong);
  border-radius: var(--radius-md);
  transition: border-color 150ms ease;
}

.calc-select {
  font-family: var(--font-sans);
  font-size: 0.925rem;
  font-weight: 600;
  background-color: var(--bg-canvas);
  cursor: pointer;
}

.calc-input:hover,
.calc-select:hover {
  border-color: var(--text-primary);
}

.calc-input:focus,
.calc-select:focus {
  border-color: var(--accent-primary);
  outline: 2px solid var(--accent-bright);
  outline-offset: 1px;
}

.calc-input[aria-invalid="true"] {
  border-color: var(--status-error);
  background-color: var(--status-error-bg);
}

/* Validation Error Alert */
.calc-field-error {
  display: none;
  margin-top: 0.35rem;
  padding: 0.4rem 0.65rem;
  font-size: 0.825rem;
  font-weight: 600;
  color: var(--status-error);
  background-color: var(--status-error-bg);
  border-left: 3px solid var(--status-error);
  border-radius: 2px;
}

.calc-field-error.is-visible {
  display: block;
}

/* Material & Density Box */
.calc-material-box {
  background: var(--bg-canvas);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1rem;
  margin-bottom: 1.25rem;
}

.calc-density-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  margin-top: 0.65rem;
  padding-top: 0.65rem;
  border-top: 1px solid var(--border-color);
  font-size: 0.825rem;
  color: var(--text-secondary);
}

.btn-link-inline {
  background: none;
  border: none;
  padding: 0.25rem 0;
  font-family: var(--font-sans);
  font-size: 0.825rem;
  font-weight: 600;
  color: var(--accent-primary);
  text-decoration: underline;
  cursor: pointer;
}

/* Waste Factor Controls */
.waste-presets-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 0.4rem;
  margin-bottom: 0.65rem;
}

.btn-waste {
  min-height: 44px;
  padding: 0.4rem 0.25rem;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  font-weight: 600;
  background: var(--bg-canvas);
  color: var(--text-primary);
  border: 1.5px solid var(--border-color);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all 150ms ease;
}

.btn-waste:hover {
  border-color: var(--accent-primary);
}

.btn-waste[aria-pressed="true"] {
  background: var(--panel-dark);
  color: #ffffff;
  border-color: var(--panel-dark);
}

.waste-custom-row {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.waste-custom-row .calc-input {
  max-width: 120px;
  min-height: 44px;
}

/* Optional Cost Estimation Sub-Panel */
.calc-cost-box {
  margin-top: 1.25rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--border-color);
}

.calc-cost-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.85rem;
}

@media (min-width: 540px) {
  .calc-cost-grid {
    grid-template-columns: 1fr 1fr;
  }
}

.input-currency-wrap {
  position: relative;
  display: flex;
  align-items: center;
}

.input-currency-prefix {
  position: absolute;
  left: 0.85rem;
  font-family: var(--font-mono);
  font-weight: 600;
  color: var(--text-muted);
  pointer-events: none;
}

.input-currency-wrap .calc-input {
  padding-left: 1.85rem;
}

/* Primary Calculate & Reset Buttons */
.calc-submit-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1.5rem;
}

.btn-calculate {
  flex: 1;
  min-height: 48px;
  padding: 0.75rem 1.5rem;
  font-family: var(--font-sans);
  font-size: 1rem;
  font-weight: 700;
  color: #ffffff;
  background-color: var(--accent-primary);
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  white-space: nowrap;
  transition: background-color 150ms ease;
}

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

.btn-reset {
  min-height: 48px;
  padding: 0.75rem 1.15rem;
  font-family: var(--font-sans);
  font-size: 0.925rem;
  font-weight: 600;
  color: var(--text-secondary);
  background-color: var(--bg-canvas);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  cursor: pointer;
  white-space: nowrap;
}

.btn-reset:hover {
  background-color: var(--bg-subtle);
  color: var(--text-primary);
}

/* ==========================================================================
   Right Column: High-Contrast Job-Site Results Ticket
   ========================================================================== */
.calc-results-panel {
  background-color: var(--panel-dark);
  color: var(--panel-dark-text);
  border-radius: var(--radius-lg);
  padding: 1.35rem;
  box-shadow: var(--shadow-card);
}

@media (min-width: 640px) {
  .calc-results-panel {
    padding: 1.75rem;
  }
}

.results-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  padding-bottom: 0.9rem;
  margin-bottom: 1.15rem;
  border-bottom: 1px solid var(--panel-dark-border);
}

.results-header__title {
  font-size: 1.05rem;
  font-weight: 700;
  color: #ffffff;
  margin: 0;
}

.results-header__badge {
  font-family: var(--font-mono);
  font-size: 0.775rem;
  color: var(--accent-bright);
}

/* Primary Comparison Cards: Recommended (With Waste) vs Base */
.results-primary-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.85rem;
  margin-bottom: 1.25rem;
}

.result-highlight-box {
  background: var(--panel-dark-elevated);
  border: 1px solid var(--panel-dark-border);
  border-radius: var(--radius-md);
  padding: 1rem 1.15rem;
}

.result-highlight-box--recommended {
  border-left: 4px solid var(--accent-bright);
  background: rgba(245, 158, 11, 0.08);
}

.result-highlight-box__kicker {
  font-size: 0.775rem;
  font-weight: 600;
  color: var(--panel-dark-muted);
  margin-bottom: 0.35rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.result-highlight-box__main {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.75rem;
}

.result-big-metric {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(1.55rem, 2.5vw, 2rem);
  font-weight: 700;
  color: #ffffff;
  line-height: 1.15;
}

.result-big-metric--accent {
  color: #fbbf24;
}

.result-big-unit {
  font-family: var(--font-sans);
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--panel-dark-muted);
  margin-left: 0.25rem;
}

.result-secondary-metric {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 1.15rem;
  font-weight: 600;
  color: #e2e8f0;
}

/* Complete Unit Breakdown Table (Base vs Adjustment vs Recommended) */
.results-table-wrap {
  width: 100%;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  margin-bottom: 1.25rem;
}

.results-breakdown-table {
  width: 100%;
  min-width: 320px;
  border-collapse: collapse;
  font-size: 0.85rem;
}

.results-breakdown-table th {
  text-align: left;
  font-weight: 600;
  color: var(--panel-dark-muted);
  padding: 0.5rem 0.4rem;
  border-bottom: 1px solid var(--panel-dark-border);
  font-size: 0.775rem;
}

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

.results-breakdown-table td {
  padding: 0.55rem 0.4rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.07);
  color: #e2e8f0;
}

.results-breakdown-table td.rec-col {
  color: #fde68a;
  font-weight: 700;
}

/* Estimated Cost Output Box */
.results-cost-panel {
  background: var(--panel-dark-elevated);
  border: 1px solid var(--panel-dark-border);
  border-radius: var(--radius-md);
  padding: 1rem;
  margin-bottom: 1.15rem;
}

.results-cost-panel__title {
  font-size: 0.825rem;
  font-weight: 600;
  color: var(--accent-bright);
  margin-bottom: 0.5rem;
}

.results-cost-row {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding: 0.3rem 0;
  font-size: 0.9rem;
}

.results-cost-row--total {
  border-top: 1px solid var(--panel-dark-border);
  margin-top: 0.35rem;
  padding-top: 0.55rem;
  font-weight: 700;
  font-size: 1.05rem;
  color: #ffffff;
}

.results-cost-disclaimer {
  margin-top: 0.5rem;
  font-size: 0.75rem;
  color: var(--panel-dark-muted);
  line-height: 1.45;
}

/* Practical Job-Site Summary Strip */
.results-jobsite-meta {
  background: rgba(255, 255, 255, 0.04);
  border-radius: var(--radius-sm);
  padding: 0.75rem 0.9rem;
  margin-bottom: 1.15rem;
  font-size: 0.8125rem;
  color: var(--panel-dark-muted);
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.5rem;
}

.results-jobsite-meta strong {
  color: #ffffff;
  font-family: var(--font-mono);
}

/* Mandatory Density Disclaimer */
.density-disclaimer {
  background: rgba(255, 255, 255, 0.05);
  border-left: 3px solid var(--accent-bright);
  padding: 0.75rem 0.9rem;
  font-size: 0.78rem;
  line-height: 1.5;
  color: var(--panel-dark-muted);
  margin-bottom: 1.15rem;
}

/* Utility Actions (Print & Copy) */
.results-actions {
  display: flex;
  gap: 0.65rem;
}

.btn-result-action {
  flex: 1;
  min-height: 44px;
  padding: 0.5rem 0.85rem;
  font-family: var(--font-sans);
  font-size: 0.85rem;
  font-weight: 600;
  color: #ffffff;
  background: var(--panel-dark-elevated);
  border: 1px solid var(--panel-dark-border);
  border-radius: var(--radius-md);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  white-space: nowrap;
}

.btn-result-action:hover {
  border-color: var(--accent-bright);
  background: #2c343c;
}

/* ==========================================================================
   Content Sections, Tables, Formula Boxes & Examples
   ========================================================================== */
.content-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2.25rem;
  margin-bottom: 3rem;
}

@media (min-width: 960px) {
  .content-grid--sidebar {
    grid-template-columns: 8fr 4fr;
    gap: 2.5rem;
  }
}

.content-section {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  margin-bottom: 1.75rem;
}

@media (min-width: 640px) {
  .content-section {
    padding: 2rem;
  }
}

.formula-card {
  background: var(--bg-canvas);
  border-left: 4px solid var(--accent-primary);
  padding: 1.15rem 1.25rem;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  margin: 1.25rem 0;
  font-family: var(--font-mono);
  font-size: 0.925rem;
  color: var(--text-primary);
  overflow-x: auto;
}

.formula-card strong {
  display: block;
  font-family: var(--font-sans);
  font-size: 0.825rem;
  color: var(--text-muted);
  margin-bottom: 0.35rem;
}

.example-box {
  background: var(--bg-subtle);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  margin: 1.25rem 0;
}

.example-box__title {
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.65rem;
  font-size: 1.05rem;
}

.example-steps {
  margin: 0;
  padding-left: 1.25rem;
  color: var(--text-secondary);
}

.example-steps li {
  margin-bottom: 0.45rem;
}

/* Data Tables */
.table-responsive {
  width: 100%;
  overflow-x: auto;
  margin: 1.25rem 0;
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.925rem;
}

.data-table th,
.data-table td {
  padding: 0.75rem 0.9rem;
  text-align: left;
  border-bottom: 1px solid var(--border-color);
}

.data-table th {
  background: var(--bg-subtle);
  font-weight: 700;
  color: var(--text-primary);
}

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

/* ==========================================================================
   Calculator Cards Grid (Homepage & Related Calculators)
   ========================================================================== */
.calc-cards-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.15rem;
  margin: 1.25rem 0 2rem;
}

@media (min-width: 640px) {
  .calc-cards-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 960px) {
  .calc-cards-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.calc-card {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.35rem;
  text-decoration: none;
  color: var(--text-primary);
  transition: border-color 150ms ease, transform 150ms ease;
}

.calc-card:hover {
  border-color: var(--accent-primary);
  transform: translateY(-2px);
}

.calc-card__kicker {
  font-size: 0.775rem;
  color: var(--text-muted);
  margin-bottom: 0.35rem;
}

.calc-card__title {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}

.calc-card__desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 1rem;
  line-height: 1.5;
}

.calc-card__footer {
  font-size: 0.825rem;
  font-weight: 600;
  color: var(--accent-primary);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 0.75rem;
  border-top: 1px solid var(--bg-subtle);
}

/* ==========================================================================
   FAQ Section
   ========================================================================== */
.faq-list {
  display: grid;
  gap: 0.85rem;
}

.faq-item {
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  background: var(--bg-canvas);
  overflow: hidden;
}

.faq-question {
  width: 100%;
  min-height: 48px;
  padding: 1rem 1.25rem;
  font-family: var(--font-sans);
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-primary);
  background: none;
  border: none;
  text-align: left;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.faq-answer {
  padding: 0 1.25rem 1.15rem;
  color: var(--text-secondary);
  font-size: 0.95rem;
}

.faq-answer p:last-child {
  margin-bottom: 0;
}

/* ==========================================================================
   Monetization Preparation (Unobtrusive Ad Placement Slots)
   Collapsed by default so blank boxes never dominate the page.
   ========================================================================== */
.ad-slot {
  display: none;
  margin: 1.25rem 0;
  text-align: center;
  overflow: hidden;
}

.ad-slot--active {
  display: block;
  min-height: 90px;
  padding: 0.5rem;
  background: var(--bg-subtle);
  border: 1px dashed var(--border-color);
  border-radius: var(--radius-sm);
}

/* ==========================================================================
   Footer
   ========================================================================== */
.site-footer {
  background: var(--panel-dark);
  color: var(--panel-dark-muted);
  padding: 3rem 0 2.5rem;
  margin-top: 4rem;
  border-top: 3px solid var(--accent-primary);
}

.site-footer__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
  margin-bottom: 2.5rem;
}

@media (min-width: 768px) {
  .site-footer__grid {
    grid-template-columns: 2fr 1.5fr 1.5fr 1fr;
  }
}

.site-footer__heading {
  font-size: 0.95rem;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 0.85rem;
}

.site-footer__links {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 0.45rem;
}

.site-footer__links a {
  color: var(--panel-dark-muted);
  text-decoration: none;
  font-size: 0.875rem;
  display: inline-block;
  padding: 0.2rem 0;
}

.site-footer__links a:hover {
  color: #ffffff;
  text-decoration: underline;
}

.site-footer__bottom {
  padding-top: 1.5rem;
  border-top: 1px solid var(--panel-dark-border);
  font-size: 0.8125rem;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 1rem;
}

/* ==========================================================================
   Print Stylesheet (Clean Job-Site Estimate Printout)
   ========================================================================== */
@media print {
  body {
    background: #ffffff !important;
    color: #000000 !important;
    font-size: 11pt;
  }

  .site-header,
  .mobile-drawer,
  .breadcrumbs,
  .calc-presets,
  .calc-mode-tabs,
  .calc-submit-row,
  .results-actions,
  .ad-slot,
  .related-calculators-section,
  .site-footer,
  .no-print {
    display: none !important;
  }

  .container {
    max-width: 100% !important;
    padding: 0 !important;
  }

  .calculator-workbench {
    display: block !important;
  }

  .calc-form-panel,
  .calc-results-panel,
  .content-section {
    background: #ffffff !important;
    color: #000000 !important;
    border: 1px solid #000000 !important;
    box-shadow: none !important;
    margin-bottom: 1rem !important;
    page-break-inside: avoid;
  }

  .results-header__title,
  .result-big-metric,
  .result-secondary-metric,
  .results-breakdown-table td,
  .results-breakdown-table th,
  .results-cost-row--total,
  .results-jobsite-meta strong {
    color: #000000 !important;
  }

  .result-highlight-box {
    background: #f8f8f8 !important;
    border: 1px solid #444444 !important;
  }

  a {
    text-decoration: none !important;
    color: #000000 !important;
  }
}