/* ==========================================================================
   ProfitPilot Tools - Design System & Global Stylesheet
   Modern, accessible, fast, clean productivity UI
   ========================================================================== */

:root {
  /* Color Palette */
  --color-primary: #0d9488;          /* Teal 600 */
  --color-primary-hover: #0f766e;    /* Teal 700 */
  --color-primary-light: #f0fdfa;    /* Teal 50 */
  --color-primary-border: #99f6e4;   /* Teal 200 */
  --color-secondary: #0284c7;        /* Sky 600 */

  --color-text-main: #0f172a;        /* Dark Navy / Slate 900 */
  --color-text-muted: #475569;       /* Slate 600 */
  --color-text-light: #64748b;       /* Slate 500 */
  --color-bg-body: #f8fafc;          /* Slate 50 */
  --color-bg-card: #ffffff;          /* Pure White */
  --color-bg-subtle: #f1f5f9;        /* Slate 100 */

  --color-border: #e2e8f0;          /* Slate 200 */
  --color-border-focus: #0d9488;
  
  --color-success: #15803d;         /* Green 700 */
  --color-success-bg: #f0fdf4;
  --color-danger: #b91c1c;          /* Red 700 (Loss/Error) */
  --color-danger-bg: #fef2f2;
  --color-danger-border: #fecaca;
  --color-warning: #b45309;         /* Amber 700 */
  --color-warning-bg: #fffbeb;

  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;

  /* Spacing */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;

  /* Borders & Shadows */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.04);

  /* Container */
  --max-width: 1200px;
  --transition-fast: 150ms ease-in-out;
}

/* Reset & Base */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.5;
  color: var(--color-text-main);
  background-color: var(--color-bg-body);
  -webkit-text-size-adjust: 100%;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover, a:focus-visible {
  color: var(--color-primary-hover);
  text-decoration: underline;
}

/* Accessibility Focus Ring */
:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* Skip link */
.skip-link {
  position: absolute;
  top: -100px;
  left: 1rem;
  background: var(--color-primary);
  color: #fff;
  padding: 0.75rem 1.25rem;
  border-radius: var(--radius-md);
  z-index: 9999;
  font-weight: 600;
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: 1rem;
}

/* Containers */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--space-md);
  padding-right: var(--space-md);
}

/* Header & Navigation */
.site-header {
  background-color: var(--color-bg-card);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: var(--shadow-sm);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 4.25rem;
  gap: var(--space-md);
}

.brand-link {
  display: flex;
  align-items: center;
  gap: 0.625rem;
  text-decoration: none;
}

.brand-logo {
  height: 38px;
  width: auto;
  display: block;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
}

.nav-list {
  display: flex;
  align-items: center;
  list-style: none;
  gap: var(--space-lg);
}

.nav-link {
  color: var(--color-text-main);
  font-weight: 500;
  font-size: 0.95rem;
  padding: 0.375rem 0.125rem;
  border-bottom: 2px solid transparent;
  transition: all var(--transition-fast);
}

.nav-link:hover, .nav-link:focus-visible, .nav-link.active {
  color: var(--color-primary);
  text-decoration: none;
  border-bottom-color: var(--color-primary);
}

.header-search {
  display: flex;
  align-items: center;
  position: relative;
}

.header-search-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  background-color: var(--color-bg-subtle);
  border: 1px solid var(--color-border);
  color: var(--color-text-muted);
  font-size: 0.875rem;
  padding: 0.5rem 0.875rem;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.header-search-btn:hover {
  background-color: #e2e8f0;
  color: var(--color-text-main);
}

/* Mobile Nav Toggle */
.mobile-nav-toggle {
  display: none;
  background: transparent;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 0.5rem;
  color: var(--color-text-main);
  cursor: pointer;
}

/* Breadcrumbs */
.breadcrumb-nav {
  padding: var(--space-md) 0;
  font-size: 0.875rem;
  color: var(--color-text-light);
}

.breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  list-style: none;
  gap: 0.375rem;
}

.breadcrumb-item a {
  color: var(--color-text-muted);
}

.breadcrumb-item a:hover {
  color: var(--color-primary);
}

.breadcrumb-item.current {
  color: var(--color-text-main);
  font-weight: 600;
}

.breadcrumb-sep {
  user-select: none;
  color: var(--color-border);
}

/* Typography Hierarchy */
h1, h2, h3, h4 {
  color: var(--color-text-main);
  font-weight: 700;
  line-height: 1.25;
}

h1 { font-size: 2.25rem; letter-spacing: -0.025em; margin-bottom: var(--space-sm); }
h2 { font-size: 1.5rem; letter-spacing: -0.015em; margin-bottom: var(--space-sm); }
h3 { font-size: 1.25rem; margin-bottom: var(--space-xs); }
h4 { font-size: 1.1rem; }

p {
  color: var(--color-text-muted);
  line-height: 1.6;
  margin-bottom: var(--space-md);
}

/* Hero Section */
.hero-section {
  background: linear-gradient(180deg, #ffffff 0%, var(--color-bg-body) 100%);
  border-bottom: 1px solid var(--color-border);
  padding: var(--space-3xl) 0 var(--space-2xl);
  text-align: center;
}

.hero-title {
  font-size: 2.75rem;
  font-weight: 800;
  color: var(--color-text-main);
  max-width: 800px;
  margin: 0 auto var(--space-md);
  letter-spacing: -0.03em;
}

.hero-subtitle {
  font-size: 1.2rem;
  color: var(--color-text-muted);
  max-width: 680px;
  margin: 0 auto var(--space-xl);
}

.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-md);
  flex-wrap: wrap;
  margin-bottom: var(--space-xl);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.375rem;
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
  border: 1px solid transparent;
  text-decoration: none;
}

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

.btn-primary:hover, .btn-primary:focus-visible {
  background-color: var(--color-primary-hover);
  color: #ffffff;
  text-decoration: none;
}

.btn-secondary {
  background-color: var(--color-bg-card);
  color: var(--color-text-main);
  border-color: var(--color-border);
}

.btn-secondary:hover, .btn-secondary:focus-visible {
  background-color: var(--color-bg-subtle);
  color: var(--color-text-main);
  text-decoration: none;
}

.btn-outline {
  background: transparent;
  border-color: var(--color-primary);
  color: var(--color-primary);
}

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

.btn-sm {
  padding: 0.4rem 0.8rem;
  font-size: 0.875rem;
}

/* Quick Search Box (Hero / All Tools) */
.search-widget {
  max-width: 640px;
  margin: 0 auto;
  position: relative;
}

.search-input-wrapper {
  position: relative;
  display: flex;
  align-items: center;
}

.search-icon {
  position: absolute;
  left: 1rem;
  color: var(--color-text-light);
  pointer-events: none;
}

.search-input {
  width: 100%;
  padding: 0.875rem 1rem 0.875rem 2.75rem;
  font-size: 1rem;
  border: 2px solid var(--color-border);
  border-radius: var(--radius-lg);
  background-color: #ffffff;
  color: var(--color-text-main);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-fast);
}

.search-input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(13, 148, 136, 0.15);
}

.search-clear-btn {
  position: absolute;
  right: 0.75rem;
  background: transparent;
  border: none;
  color: var(--color-text-light);
  cursor: pointer;
  padding: 0.375rem;
  display: none;
}

.search-results-dropdown {
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  margin-top: 0.5rem;
  box-shadow: var(--shadow-lg);
  max-height: 380px;
  overflow-y: auto;
  z-index: 100;
  display: none;
  text-align: left;
}

.search-result-item {
  display: block;
  padding: 0.75rem 1rem;
  border-bottom: 1px solid var(--color-bg-subtle);
  color: var(--color-text-main);
  text-decoration: none;
  transition: background var(--transition-fast);
}

.search-result-item:hover, .search-result-item:focus {
  background-color: var(--color-primary-light);
  text-decoration: none;
}

.search-result-item:last-child {
  border-bottom: none;
}

.search-result-title {
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 0.2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.search-result-cat {
  font-size: 0.75rem;
  text-transform: uppercase;
  color: var(--color-text-light);
  background: var(--color-bg-subtle);
  padding: 0.125rem 0.375rem;
  border-radius: var(--radius-sm);
}

.search-result-desc {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  line-height: 1.4;
  margin-bottom: 0;
}

.search-empty {
  padding: 1.25rem;
  text-align: center;
  color: var(--color-text-muted);
}

/* Cards & Grid */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--space-lg);
  margin-top: var(--space-lg);
  margin-bottom: var(--space-2xl);
}

.tool-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  display: flex;
  flex-direction: column;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast), border-color var(--transition-fast);
  box-shadow: var(--shadow-sm);
}

.tool-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  border-color: var(--color-primary-border);
}

.tool-card-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  background: var(--color-primary-light);
  color: var(--color-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--space-md);
}

.tool-card-title {
  font-size: 1.25rem;
  margin-bottom: 0.5rem;
}

.tool-card-title a {
  color: var(--color-text-main);
  text-decoration: none;
}

.tool-card-title a:hover {
  color: var(--color-primary);
}

.tool-card-desc {
  font-size: 0.925rem;
  color: var(--color-text-muted);
  flex-grow: 1;
  margin-bottom: var(--space-md);
}

.tool-card-usecase {
  font-size: 0.8rem;
  color: var(--color-text-light);
  background: var(--color-bg-subtle);
  padding: 0.375rem 0.625rem;
  border-radius: var(--radius-sm);
  margin-bottom: var(--space-md);
}

.tool-card-link {
  font-size: 0.9rem;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
}

/* Category Sections */
.section {
  padding: var(--space-3xl) 0;
}

.section-alt {
  background-color: #ffffff;
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}

.section-header {
  text-align: center;
  max-width: 720px;
  margin: 0 auto var(--space-xl);
}

/* Steps / How It Works */
.steps-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: var(--space-lg);
  margin-top: var(--space-xl);
}

.step-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  text-align: center;
}

.step-number {
  width: 40px;
  height: 40px;
  background: var(--color-primary);
  color: #fff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  margin: 0 auto var(--space-md);
}

/* Trust / Privacy Banner */
.trust-banner {
  background-color: var(--color-primary-light);
  border: 1px solid var(--color-primary-border);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  display: flex;
  align-items: center;
  gap: var(--space-lg);
  margin: var(--space-2xl) 0;
}

.trust-icon {
  flex-shrink: 0;
  color: var(--color-primary);
}

.trust-content h3 {
  color: var(--color-primary-hover);
}

.trust-content p {
  color: #134e4a;
  margin-bottom: 0;
}

/* ==========================================================================
   CALCULATOR APPLICATION LAYOUT
   ========================================================================== */

.calc-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-xl);
  margin-top: var(--space-lg);
  margin-bottom: var(--space-2xl);
}

.calc-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-xl);
  box-shadow: var(--shadow-sm);
}

.calc-card-header {
  margin-bottom: var(--space-lg);
  border-bottom: 1px solid var(--color-border);
  padding-bottom: var(--space-md);
}

/* Form Controls */
.form-group {
  margin-bottom: var(--space-lg);
}

.form-label {
  display: block;
  font-weight: 600;
  font-size: 0.95rem;
  margin-bottom: 0.375rem;
  color: var(--color-text-main);
}

.form-hint {
  font-size: 0.8rem;
  color: var(--color-text-light);
  margin-bottom: 0.375rem;
}

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

.input-symbol {
  position: absolute;
  left: 0.875rem;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--color-text-light);
  pointer-events: none;
}

.form-control {
  width: 100%;
  padding: 0.6875rem 0.875rem;
  font-size: 1rem;
  font-family: inherit;
  color: var(--color-text-main);
  background-color: #ffffff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.input-with-symbol .form-control {
  padding-left: 2rem;
}

.form-control:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(13, 148, 136, 0.15);
}

.form-control[aria-invalid="true"] {
  border-color: var(--color-danger);
  background-color: #fffafa;
}

.field-error {
  color: var(--color-danger);
  font-size: 0.85rem;
  font-weight: 500;
  margin-top: 0.25rem;
  display: none;
}

.field-error.active {
  display: block;
}

.calc-actions {
  display: flex;
  gap: var(--space-md);
  margin-top: var(--space-xl);
}

/* Results Panel */
.results-panel {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-xl);
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
}

.results-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--color-border);
  padding-bottom: var(--space-md);
  margin-bottom: var(--space-lg);
}

.results-primary-card {
  background: var(--color-primary-light);
  border: 1px solid var(--color-primary-border);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  margin-bottom: var(--space-lg);
  text-align: center;
}

.results-primary-card.is-loss {
  background: var(--color-danger-bg);
  border-color: var(--color-danger-border);
}

.results-primary-label {
  font-size: 0.875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-muted);
  margin-bottom: 0.25rem;
}

.results-primary-value {
  font-size: 2.25rem;
  font-weight: 800;
  color: var(--color-primary-hover);
  line-height: 1.1;
  font-family: var(--font-sans);
}

.is-loss .results-primary-value {
  color: var(--color-danger);
}

.results-badge-loss {
  display: inline-block;
  background: var(--color-danger);
  color: #fff;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.15rem 0.5rem;
  border-radius: var(--radius-sm);
  margin-top: 0.5rem;
}

.results-breakdown-list {
  list-style: none;
  border-top: 1px solid var(--color-border);
  margin-bottom: var(--space-lg);
}

.results-breakdown-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.75rem 0;
  border-bottom: 1px solid var(--color-border);
  font-size: 0.95rem;
}

.breakdown-label {
  color: var(--color-text-muted);
}

.breakdown-val {
  font-weight: 600;
  color: var(--color-text-main);
  font-family: var(--font-sans);
}

.copy-feedback {
  font-size: 0.85rem;
  color: var(--color-success);
  margin-top: 0.5rem;
  font-weight: 500;
  display: none;
}

.copy-feedback.active {
  display: block;
}

/* Educational Explanations on Tool Pages */
.tool-content-section {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-xl);
  margin-bottom: var(--space-xl);
}

.formula-box {
  background: var(--color-bg-subtle);
  border-left: 4px solid var(--color-primary);
  padding: var(--space-md) var(--space-lg);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  font-family: var(--font-mono);
  font-size: 0.95rem;
  color: var(--color-text-main);
  margin: var(--space-md) 0;
  overflow-x: auto;
}

.example-box {
  background: #f8fafc;
  border: 1px dashed var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-md) var(--space-lg);
  margin: var(--space-md) 0;
}

.faq-accordion {
  margin-top: var(--space-md);
}

.faq-item {
  border-bottom: 1px solid var(--color-border);
  padding: var(--space-md) 0;
}

.faq-question {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--color-text-main);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  user-select: none;
}

.faq-answer {
  margin-top: var(--space-sm);
  font-size: 0.95rem;
  color: var(--color-text-muted);
}

/* Monetization / Future Ad Placeholder Container */
.ad-slot-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background-color: var(--color-bg-subtle);
  border: 1px dashed var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  margin: var(--space-2xl) 0;
  min-height: 100px;
  text-align: center;
}

.ad-slot-label {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-light);
}

/* Footer */
.site-footer {
  background-color: #0f172a;
  color: #94a3b8;
  padding: var(--space-3xl) 0 var(--space-xl);
  margin-top: auto;
  border-top: 1px solid #1e293b;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--space-xl);
  margin-bottom: var(--space-2xl);
}

.footer-brand h4 {
  color: #f8fafc;
  font-size: 1.25rem;
  margin-bottom: 0.5rem;
}

.footer-brand p {
  color: #94a3b8;
  font-size: 0.9rem;
  max-width: 320px;
}

.footer-col h5 {
  color: #f8fafc;
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: var(--space-md);
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.625rem;
}

.footer-links a {
  color: #94a3b8;
  font-size: 0.9rem;
  text-decoration: none;
  transition: color var(--transition-fast);
}

.footer-links a:hover, .footer-links a:focus-visible {
  color: #38bdf8;
  text-decoration: underline;
}

.footer-bottom {
  border-top: 1px solid #1e293b;
  padding-top: var(--space-lg);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.85rem;
}

.footer-bottom p {
  margin-bottom: 0;
  color: #64748b;
}

/* Screen Reader Only Utility */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}