/* ==========================================================================
   GulfCalc (gulfcalc.tech): Master Fintech Design System & Utilities
   Aesthetic: Ultra-Clean European Fintech (Slate Neutrals, Emerald/Indigo Accents)
   ========================================================================== */

:root {
  /* Slate Color Scale */
  --slate-50:  #f8fafc;
  --slate-100: #f1f5f9;
  --slate-200: #e2e8f0;
  --slate-300: #cbd5e1;
  --slate-400: #94a3b8;
  --slate-500: #64748b;
  --slate-600: #475569;
  --slate-700: #334155;
  --slate-800: #1e293b;
  --slate-900: #0f172a;
  --slate-950: #020617;

  /* Functional Accents */
  --emerald-50:  #ecfdf5;
  --emerald-100: #d1fae5;
  --emerald-600: #047857;
  --emerald-700: #047857;
  --emerald-800: #065f46;

  --indigo-50:  #eef2ff;
  --indigo-100: #e0e7ff;
  --indigo-600: #4f46e5;
  --indigo-700: #4338ca;

  --amber-50:  #fffbeb;
  --amber-100: #fef3c7;
  --amber-600: #d97706;

  /* Semantic Variables */
  --bg-body: #f8fafc;
  --bg-card: #ffffff;
  --border-subtle: #e2e8f0;
  --border-hover: #cbd5e1;
  --text-main: #0f172a;
  --text-muted: #64748b;
  --text-subtle: #94a3b8;

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

  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-card: 0 4px 6px -1px rgb(0 0 0 / 0.04), 0 2px 4px -2px rgb(0 0 0 / 0.04);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.07), 0 4px 6px -4px rgb(0 0 0 / 0.03);

  /* Radius */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 20px;
}

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

html {
  font-family: var(--font-sans);
  background-color: var(--bg-body);
  color: var(--text-main);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  scroll-behavior: smooth;
}

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

a {
  color: inherit;
  text-decoration: none;
}

button, input, select, textarea {
  font: inherit;
}

/* Layout Utilities */
.container {
  width: 100%;
  max-width: 1200px;
  margin-left: auto;
  margin-right: auto;
  padding-left: clamp(1rem, 3vw, 2rem);
  padding-right: clamp(1rem, 3vw, 2rem);
}

/* Sticky Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background-color: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-subtle);
  transition: border-color 0.2s ease;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.625rem;
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--slate-900);
  letter-spacing: -0.02em;
}

.brand-badge {
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  background-color: var(--emerald-50);
  color: var(--emerald-700);
  border: 1px solid var(--emerald-100);
  padding: 0.125rem 0.45rem;
  border-radius: var(--radius-sm);
}

.nav-links {
  display: none;
  align-items: center;
  gap: 1.5rem;
}

@media (min-width: 860px) {
  .nav-links {
    display: flex;
  }
}

.nav-link {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--slate-600);
  transition: color 0.15s ease;
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
}

.nav-link:hover, .nav-link.active {
  color: var(--slate-900);
}

.mobile-menu-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background: transparent;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  cursor: pointer;
  color: var(--slate-700);
}

@media (min-width: 860px) {
  .mobile-menu-btn {
    display: none;
  }
}

/* Mobile Drawer */
.mobile-drawer {
  display: none;
  position: fixed;
  inset: 64px 0 0 0;
  background-color: var(--bg-card);
  padding: 1.5rem;
  overflow-y: auto;
  border-top: 1px solid var(--border-subtle);
  z-index: 49;
}

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

.mobile-nav-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  list-style: none;
}

.mobile-nav-item a {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.875rem 1rem;
  border-radius: var(--radius-md);
  font-weight: 500;
  color: var(--slate-800);
  background-color: var(--slate-50);
  border: 1px solid var(--border-subtle);
}

/* Page Header & Breadcrumbs */
.page-header {
  padding-top: 2rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--border-subtle);
  background-color: #ffffff;
}

.breadcrumb-nav {
  margin-bottom: 0.75rem;
}

.breadcrumbs {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.8125rem;
  color: var(--slate-500);
  list-style: none;
}

.breadcrumb-item a {
  color: var(--slate-600);
  transition: color 0.15s;
}

.breadcrumb-item a:hover {
  color: var(--slate-900);
}

.breadcrumb-separator {
  color: var(--slate-400);
}

.page-title {
  font-size: clamp(1.75rem, 3.5vw, 2.5rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--slate-900);
  line-height: 1.2;
  margin-bottom: 0.75rem;
}

/* 50-word Direct Summary Answer Block (SEO / AIO) */
.direct-answer-callout {
  background: var(--slate-50);
  border: 1px solid var(--border-subtle);
  border-left: 4px solid var(--emerald-600);
  border-radius: var(--radius-md);
  padding: 1rem 1.25rem;
  font-size: 0.9375rem;
  color: var(--slate-700);
  line-height: 1.6;
  margin-top: 1rem;
}

.direct-answer-callout strong {
  color: var(--slate-900);
}

/* Calculator Grid (7-col engine + 5-col sticky result) */
.calculator-workspace {
  padding-top: 2.5rem;
  padding-bottom: 4rem;
}

.workspace-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
  align-items: start;
}

@media (min-width: 1024px) {
  .workspace-grid {
    grid-template-columns: 7fr 5fr;
  }
}

/* Input Form Card */
.calc-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-xl);
  padding: clamp(1.25rem, 2.5vw, 2rem);
  box-shadow: var(--shadow-card);
}

.card-heading {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--slate-900);
  margin-bottom: 0.375rem;
  display: flex;
  align-items: center;
  gap: 0.625rem;
}

.card-subtext {
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-bottom: 1.75rem;
}

/* Form Controls & Dual Inputs */
.form-group {
  margin-bottom: 1.75rem;
}

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

.form-label {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--slate-800);
}

.form-help {
  font-size: 0.75rem;
  color: var(--slate-500);
}

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

.input-prefix {
  position: absolute;
  left: 1rem;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--slate-500);
  pointer-events: none;
  font-family: var(--font-mono);
}

.form-input {
  width: 100%;
  height: 50px;
  background-color: var(--slate-50);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 0 1rem 0 3.25rem;
  font-size: 1.0625rem;
  font-weight: 600;
  color: var(--slate-900);
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  transition: all 0.15s ease;
}

.form-input.no-prefix {
  padding-left: 1rem;
}

.form-input:focus {
  outline: none;
  border-color: var(--indigo-600);
  background-color: #ffffff;
  box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.12);
}

/* Dual Range Slider */
.slider-container {
  margin-top: 0.75rem;
}

.range-slider {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 6px;
  border-radius: 9999px;
  background: var(--slate-200);
  outline: none;
  cursor: pointer;
}

.range-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: var(--indigo-600);
  border: 3px solid #ffffff;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.25);
  cursor: grab;
  transition: transform 0.1s ease;
}

.range-slider::-webkit-slider-thumb:hover {
  transform: scale(1.15);
}

.range-slider::-moz-range-thumb {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--indigo-600);
  border: 3px solid #ffffff;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.25);
  cursor: grab;
}

.slider-scale-labels {
  display: flex;
  justify-content: space-between;
  margin-top: 0.375rem;
  font-size: 0.6875rem;
  color: var(--slate-400);
  font-family: var(--font-mono);
}

/* Segmented Toggle Control */
.segmented-control {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(130px, 1fr));
  gap: 0.375rem;
  background-color: var(--slate-100);
  padding: 0.375rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
}

.segmented-option {
  position: relative;
}

.segmented-option input[type="radio"] {
  position: absolute;
  opacity: 0;
  width: 0;
  height: 0;
}

.segmented-option label {
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 0.625rem 0.75rem;
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--slate-600);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all 0.15s ease;
  user-select: none;
  min-height: 44px;
}

.segmented-option input[type="radio"]:checked + label {
  background-color: #ffffff;
  color: var(--slate-900);
  box-shadow: var(--shadow-sm);
  border: 1px solid rgba(0, 0, 0, 0.04);
}

/* Live Result Sticky Card */
.result-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-xl);
  padding: clamp(1.25rem, 2.5vw, 2rem);
  box-shadow: var(--shadow-card);
  position: sticky;
  top: 84px;
}

.result-header {
  border-bottom: 1px solid var(--border-subtle);
  padding-bottom: 1.25rem;
  margin-bottom: 1.25rem;
}

.result-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  font-size: 0.6875rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--emerald-700);
  background-color: var(--emerald-50);
  border: 1px solid var(--emerald-100);
  padding: 0.25rem 0.5rem;
  border-radius: var(--radius-sm);
  margin-bottom: 0.75rem;
}

.result-amount-display {
  font-size: clamp(2rem, 3.5vw, 2.75rem);
  font-weight: 800;
  letter-spacing: -0.04em;
  color: var(--slate-950);
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  line-height: 1;
  margin-bottom: 0.5rem;
}

.result-currency {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--slate-500);
  margin-right: 0.25rem;
}

.result-caption {
  font-size: 0.8125rem;
  color: var(--text-muted);
}

/* Breakdown Rows */
.breakdown-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
}

.breakdown-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.875rem;
  padding-bottom: 0.625rem;
  border-bottom: 1px dashed var(--slate-200);
}

.breakdown-row:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.breakdown-label {
  color: var(--slate-600);
}

.breakdown-value {
  font-weight: 600;
  color: var(--slate-900);
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
}

/* Card Action Buttons */
.action-buttons {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  height: 48px;
  padding: 0 1rem;
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s ease;
  border: 1px solid transparent;
  user-select: none;
}

.btn-primary {
  background-color: var(--slate-900);
  color: #ffffff;
}

.btn-primary:hover {
  background-color: var(--slate-800);
}

.btn-secondary {
  background-color: #ffffff;
  color: var(--slate-700);
  border-color: var(--border-subtle);
}

.btn-secondary:hover {
  background-color: var(--slate-50);
  border-color: var(--border-hover);
  color: var(--slate-900);
}

/* Rich Editorial Content (AdSense Quality Defense) */
.content-section {
  padding-top: 3.5rem;
  padding-bottom: 3.5rem;
  border-top: 1px solid var(--border-subtle);
  background-color: #ffffff;
}

.content-article {
  max-width: 860px;
  margin: 0 auto;
}

.article-h2 {
  font-size: 1.625rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--slate-900);
  margin-top: 2.25rem;
  margin-bottom: 1rem;
}

.article-h2:first-child {
  margin-top: 0;
}

.article-h3 {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--slate-900);
  margin-top: 1.75rem;
  margin-bottom: 0.75rem;
}

.article-p {
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--slate-700);
  margin-bottom: 1.25rem;
}

.article-p strong {
  color: var(--slate-900);
}

/* Formula Mathematical Callout Box */
.formula-box {
  background: var(--slate-900);
  color: #ffffff;
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  margin: 1.5rem 0;
  font-family: var(--font-mono);
  font-size: 0.9375rem;
  line-height: 1.6;
  border: 1px solid var(--slate-800);
  overflow-x: auto;
}

.formula-title {
  color: var(--emerald-100);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  margin-bottom: 0.5rem;
  font-family: var(--font-sans);
}

/* Benchmark Tables */
.table-wrapper {
  overflow-x: auto;
  margin: 1.5rem 0;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  background-color: #ffffff;
}

.benchmark-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 0.875rem;
}

.benchmark-table th {
  background-color: var(--slate-50);
  padding: 0.875rem 1rem;
  font-weight: 600;
  color: var(--slate-700);
  border-bottom: 1px solid var(--border-subtle);
}

.benchmark-table td {
  padding: 0.875rem 1rem;
  border-bottom: 1px solid var(--slate-100);
  color: var(--slate-800);
}

.benchmark-table tr:last-child td {
  border-bottom: none;
}

/* Scenario Cards */
.scenarios-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.25rem;
  margin: 1.5rem 0;
}

@media (min-width: 640px) {
  .scenarios-grid {
    grid-template-columns: 1fr 1fr;
  }
}

.scenario-card {
  background-color: var(--slate-50);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 1.25rem;
}

.scenario-badge {
  display: inline-block;
  font-size: 0.6875rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  padding: 0.2rem 0.5rem;
  border-radius: var(--radius-sm);
  margin-bottom: 0.75rem;
  background-color: var(--indigo-50);
  color: var(--indigo-700);
  border: 1px solid var(--indigo-100);
}

.scenario-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--slate-900);
  margin-bottom: 0.5rem;
}

.scenario-body {
  font-size: 0.875rem;
  line-height: 1.5;
  color: var(--slate-600);
}

/* FAQ Accordion */
.faq-accordion {
  margin: 1.5rem 0;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.faq-item {
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  background-color: #ffffff;
  overflow: hidden;
  transition: border-color 0.15s ease;
}

.faq-item[open] {
  border-color: var(--border-hover);
}

.faq-trigger {
  padding: 1.125rem 1.25rem;
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--slate-900);
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  user-select: none;
}

.faq-trigger::-webkit-details-marker {
  display: none;
}

.faq-icon {
  width: 18px;
  height: 18px;
  stroke: var(--slate-400);
  transition: transform 0.2s ease;
}

.faq-item[open] .faq-icon {
  transform: rotate(180deg);
  stroke: var(--slate-800);
}

.faq-content {
  padding: 0 1.25rem 1.25rem 1.25rem;
  font-size: 0.875rem;
  line-height: 1.6;
  color: var(--slate-600);
}

/* Institutional Footer */
.site-footer {
  background-color: #ffffff;
  border-top: 1px solid var(--border-subtle);
  margin-top: auto;
  padding-top: 3.5rem;
  padding-bottom: 2.5rem;
  font-size: 0.875rem;
  color: var(--slate-600);
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 2.5rem;
  margin-bottom: 3rem;
}

.footer-col-title {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--slate-900);
  margin-bottom: 1rem;
}

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

.footer-link {
  color: var(--slate-600);
  transition: color 0.15s ease;
}

.footer-link:hover {
  color: var(--slate-950);
}

.footer-bottom {
  border-top: 1px solid var(--slate-100);
  padding-top: 2rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  align-items: center;
  text-align: center;
  font-size: 0.8125rem;
  color: var(--slate-500);
}

@media (min-width: 640px) {
  .footer-bottom {
    flex-direction: row;
    justify-content: space-between;
    text-align: left;
  }
}

/* Print Stylesheet (Executive PDF Output) */
@media print {
  body {
    background: #ffffff !important;
    color: #000000 !important;
  }
  .site-header, .site-footer, .action-buttons, .slider-container, .mobile-menu-btn, .mobile-drawer, .nav-links {
    display: none !important;
  }
  .page-header {
    border-bottom: 2px solid #000000 !important;
    padding: 0 0 1rem 0 !important;
  }
  .page-header::before {
    content: "GulfCalc (gulfcalc.tech): Official Legal Calculation Record";
    display: block;
    font-size: 14pt;
    font-weight: bold;
    margin-bottom: 0.5rem;
  }
  .workspace-grid {
    display: block !important;
  }
  .calc-card, .result-card {
    border: 1px solid #999999 !important;
    box-shadow: none !important;
    page-break-inside: avoid;
    margin-bottom: 1.5rem;
  }
  .content-section {
    border-top: 1px solid #999999 !important;
  }
}