/* ============================================
   BiharTools (बिहार टूल्स) — Design System
   Simple, Clean, Mobile-First, Hindi-First
   ============================================ */

/* --- CSS Custom Properties --- */
:root {
  /* Colors */
  --primary: #FF6B35;
  --primary-dark: #E85D26;
  --primary-light: #FFF3EE;
  --primary-gradient: linear-gradient(135deg, #FF6B35, #F7931E);

  --secondary: #1B2845;
  --secondary-light: #2D3F5E;

  --bg: #F5F7FA;
  --card: #FFFFFF;
  --text: #1A1A2E;
  --text-secondary: #6B7280;
  --text-light: #9CA3AF;

  --success: #10B981;
  --success-light: #ECFDF5;
  --success-dark: #059669;

  --warning: #F59E0B;
  --warning-light: #FFFBEB;

  --info: #3B82F6;
  --info-light: #EFF6FF;

  --border: #E5E7EB;
  --border-focus: #FF6B35;

  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.08);
  --shadow-lg: 0 8px 32px rgba(0,0,0,0.12);
  --shadow-primary: 0 4px 16px rgba(255,107,53,0.3);

  /* Typography */
  --font-hindi: 'Noto Sans Devanagari', 'Segoe UI', sans-serif;
  --font-english: 'Inter', 'Segoe UI', sans-serif;

  /* Spacing */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;
  --space-3xl: 64px;

  /* Border Radius */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 50px;

  /* Transitions */
  --transition: all 0.3s ease;
  --transition-fast: all 0.15s ease;
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  scroll-padding-top: 80px;
}

body {
  font-family: var(--font-hindi);
  background-color: var(--bg);
  color: var(--text);
  line-height: 1.7;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

img {
  max-width: 100%;
  height: auto;
}

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

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

/* --- Container --- */
.container {
  width: 100%;
  max-width: 900px;
  margin: 0 auto;
  padding: 0 var(--space-md);
}

/* --- Header / Navigation --- */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  transition: var(--transition);
}

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

.logo {
  font-family: var(--font-hindi);
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--secondary);
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  cursor: pointer;
}

.logo span {
  color: var(--primary);
}

.logo-icon {
  font-size: 1.6rem;
}

.nav-links {
  display: flex;
  gap: var(--space-xs);
}

.nav-link {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-secondary);
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius-full);
  transition: var(--transition-fast);
  white-space: nowrap;
}

.nav-link:hover,
.nav-link.active {
  color: var(--primary);
  background: var(--primary-light);
}

.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  color: var(--text);
  cursor: pointer;
  padding: var(--space-sm);
  border-radius: var(--radius-sm);
  transition: var(--transition-fast);
}

.mobile-menu-btn:hover {
  background: var(--bg);
}

/* Mobile Menu */
.mobile-menu {
  display: none;
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  background: var(--card);
  border-bottom: 1px solid var(--border);
  box-shadow: var(--shadow-md);
  padding: var(--space-sm);
}

.mobile-menu.show {
  display: block;
}

.mobile-menu .nav-link {
  display: block;
  padding: var(--space-md);
  font-size: 1rem;
  border-radius: var(--radius-md);
}

/* --- Hero Section --- */
.hero {
  background: var(--primary-gradient);
  padding: var(--space-3xl) 0 var(--space-2xl);
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 500px;
  height: 500px;
  background: rgba(255,255,255,0.08);
  border-radius: 50%;
}

.hero::after {
  content: '';
  position: absolute;
  bottom: -30%;
  left: -10%;
  width: 300px;
  height: 300px;
  background: rgba(255,255,255,0.05);
  border-radius: 50%;
}

.hero-content {
  position: relative;
  z-index: 2;
}

.hero h1 {
  font-size: 1.8rem;
  font-weight: 800;
  color: #FFFFFF;
  margin-bottom: var(--space-md);
  line-height: 1.3;
}

.hero-subtitle {
  font-size: 1rem;
  color: rgba(255,255,255,0.9);
  margin-bottom: var(--space-xl);
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

/* Hero Tool Cards */
.hero-tools {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-md);
  max-width: 700px;
  margin: 0 auto;
}

.hero-tool-card {
  background: rgba(255,255,255,0.15);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid rgba(255,255,255,0.2);
  border-radius: var(--radius-lg);
  padding: var(--space-lg) var(--space-md);
  cursor: pointer;
  transition: var(--transition);
  color: #fff;
  text-align: center;
}

.hero-tool-card:hover {
  background: rgba(255,255,255,0.25);
  transform: translateY(-4px);
  color: #fff;
}

.hero-tool-icon {
  font-size: 2rem;
  margin-bottom: var(--space-sm);
  display: block;
}

.hero-tool-title {
  font-size: 0.9rem;
  font-weight: 600;
}

/* --- Tool Sections --- */
.tool-section {
  padding: var(--space-3xl) 0 var(--space-2xl);
}

.tool-section:nth-child(even) {
  background: var(--card);
}

.section-header {
  text-align: center;
  margin-bottom: var(--space-xl);
}

.section-header h2 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--secondary);
  margin-bottom: var(--space-sm);
}

.section-header p {
  font-size: 0.95rem;
  color: var(--text-secondary);
  max-width: 500px;
  margin: 0 auto;
}

.section-badge {
  display: inline-block;
  background: var(--primary-light);
  color: var(--primary);
  font-size: 0.75rem;
  font-weight: 600;
  padding: var(--space-xs) var(--space-md);
  border-radius: var(--radius-full);
  margin-bottom: var(--space-md);
  letter-spacing: 0.5px;
}

/* --- Tool Card (Main calculator container) --- */
.tool-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  box-shadow: var(--shadow-sm);
  max-width: 700px;
  margin: 0 auto;
}

.tool-section:nth-child(even) .tool-card {
  border-color: var(--bg);
  background: var(--bg);
}

/* --- Form Inputs --- */
.input-row {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-md);
  margin-bottom: var(--space-lg);
}

.input-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}

.input-label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text);
}

.input-field,
.select-field {
  width: 100%;
  height: 48px;
  padding: 0 var(--space-md);
  font-family: var(--font-hindi);
  font-size: 1rem;
  color: var(--text);
  background: var(--card);
  border: 2px solid var(--border);
  border-radius: var(--radius-md);
  transition: var(--transition-fast);
  appearance: none;
  -webkit-appearance: none;
}

.input-field:focus,
.select-field:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(255,107,53,0.15);
}

.input-field::placeholder {
  color: var(--text-light);
}

/* Select arrow */
.select-wrapper {
  position: relative;
}

.select-wrapper::after {
  content: '▾';
  position: absolute;
  right: 16px;
  top: 50%;
  transform: translateY(-50%);
  pointer-events: none;
  color: var(--text-secondary);
  font-size: 1rem;
}

.select-wrapper .select-field {
  padding-right: 40px;
}

/* --- Buttons --- */
.btn-primary {
  display: block;
  width: 100%;
  height: 52px;
  background: var(--primary-gradient);
  color: #FFFFFF;
  font-family: var(--font-hindi);
  font-size: 1.05rem;
  font-weight: 700;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: var(--transition);
  box-shadow: var(--shadow-primary);
  margin-bottom: var(--space-lg);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(255,107,53,0.4);
}

.btn-primary:active {
  transform: translateY(0);
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-md);
  font-family: var(--font-hindi);
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--primary);
  background: var(--primary-light);
  border: none;
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: var(--transition-fast);
}

.btn-secondary:hover {
  background: var(--primary);
  color: #fff;
}

/* --- Result Card --- */
.result-card {
  background: var(--success-light);
  border: 2px solid var(--success);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  text-align: center;
  animation: slideUp 0.4s ease;
}

.result-card.hidden {
  display: none;
}

.result-main {
  margin-bottom: var(--space-md);
}

.result-value {
  font-family: var(--font-english);
  font-size: 2.2rem;
  font-weight: 800;
  color: var(--success-dark);
  line-height: 1.2;
}

.result-label {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-top: var(--space-xs);
}

.result-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-md);
  margin-bottom: var(--space-md);
}

.result-item {
  padding: var(--space-md);
  background: rgba(255,255,255,0.7);
  border-radius: var(--radius-md);
}

/* --- All Conversions Grid --- */
.all-results-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-sm);
  margin-top: var(--space-md);
}

.all-results-grid.hidden {
  display: none;
}

.all-result-item {
  background: var(--info-light);
  border: 1px solid #DBEAFE;
  border-radius: var(--radius-md);
  padding: var(--space-md);
  text-align: center;
}

.all-result-item .value {
  font-family: var(--font-english);
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--info);
  display: block;
}

.all-result-item .unit {
  font-size: 0.8rem;
  color: var(--text-secondary);
  margin-top: 2px;
}

/* --- Breakdown Table --- */
.breakdown-table {
  width: 100%;
  margin-top: var(--space-md);
  border-collapse: collapse;
  font-size: 0.9rem;
  text-align: left;
}

.breakdown-table th {
  background: rgba(255,255,255,0.6);
  padding: var(--space-sm) var(--space-md);
  font-weight: 600;
  color: var(--text);
  border-bottom: 2px solid var(--success);
}

.breakdown-table td {
  padding: var(--space-sm) var(--space-md);
  border-bottom: 1px solid rgba(16,185,129,0.15);
  color: var(--text);
}

.breakdown-table tr:last-child td {
  border-bottom: none;
  font-weight: 700;
  color: var(--success-dark);
}

.breakdown-table .amount {
  font-family: var(--font-english);
  text-align: right;
  font-weight: 600;
}

/* --- Subsidy Progress Bar --- */
.subsidy-bar-container {
  margin-top: var(--space-md);
  margin-bottom: var(--space-md);
}

.subsidy-bar-label {
  display: flex;
  justify-content: space-between;
  font-size: 0.8rem;
  color: var(--text-secondary);
  margin-bottom: var(--space-xs);
}

.subsidy-bar {
  height: 12px;
  background: #DBEAFE;
  border-radius: var(--radius-full);
  overflow: hidden;
}

.subsidy-bar-fill {
  height: 100%;
  background: var(--success);
  border-radius: var(--radius-full);
  transition: width 0.6s ease;
}

/* --- Disclaimer --- */
.disclaimer {
  font-size: 0.8rem;
  color: var(--text-light);
  background: var(--warning-light);
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius-sm);
  margin-top: var(--space-md);
  border-left: 3px solid var(--warning);
}

/* --- Share Buttons --- */
.share-row {
  display: flex;
  gap: var(--space-sm);
  margin-top: var(--space-md);
  justify-content: center;
  flex-wrap: wrap;
}

.btn-whatsapp {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  background: #25D366;
  color: #fff;
  font-family: var(--font-hindi);
  font-size: 0.85rem;
  font-weight: 600;
  padding: var(--space-sm) var(--space-md);
  border: none;
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: var(--transition-fast);
}

.btn-whatsapp:hover {
  background: #1EBE57;
  transform: translateY(-1px);
}

.btn-copy {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-hindi);
  font-size: 0.85rem;
  font-weight: 600;
  padding: var(--space-sm) var(--space-md);
  border: 1px solid var(--border);
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: var(--transition-fast);
}

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

/* --- Info / SEO Text --- */
.info-section {
  max-width: 700px;
  margin: var(--space-xl) auto 0;
  padding: var(--space-lg);
  background: var(--info-light);
  border-radius: var(--radius-lg);
  border: 1px solid #DBEAFE;
}

.info-section h3 {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--secondary);
  margin-bottom: var(--space-sm);
}

.info-section p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: var(--space-sm);
}

.info-section p:last-child {
  margin-bottom: 0;
}

.info-table {
  width: 100%;
  border-collapse: collapse;
  margin-top: var(--space-md);
  font-size: 0.85rem;
}

.info-table th, .info-table td {
  padding: var(--space-sm) var(--space-md);
  text-align: left;
  border-bottom: 1px solid #DBEAFE;
}

.info-table th {
  background: rgba(59,130,246,0.08);
  font-weight: 600;
  color: var(--secondary);
}

.info-table td {
  font-family: var(--font-english);
  color: var(--text);
}

/* --- FAQ Section --- */
.faq-section {
  padding: var(--space-3xl) 0;
  background: var(--card);
}

.faq-list {
  max-width: 700px;
  margin: 0 auto;
}

.faq-item {
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  margin-bottom: var(--space-sm);
  overflow: hidden;
  transition: var(--transition-fast);
}

.faq-item:hover {
  border-color: var(--primary);
}

.faq-question {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-md) var(--space-lg);
  font-family: var(--font-hindi);
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text);
  background: none;
  border: none;
  cursor: pointer;
  text-align: left;
  transition: var(--transition-fast);
}

.faq-question:hover {
  color: var(--primary);
}

.faq-toggle {
  font-size: 1.2rem;
  color: var(--primary);
  transition: transform 0.3s ease;
  flex-shrink: 0;
  margin-left: var(--space-md);
}

.faq-item.active .faq-toggle {
  transform: rotate(180deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
}

.faq-item.active .faq-answer {
  max-height: 500px;
}

.faq-answer-inner {
  padding: 0 var(--space-lg) var(--space-lg);
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.8;
}

/* --- Footer --- */
.footer {
  background: var(--secondary);
  color: rgba(255,255,255,0.7);
  padding: var(--space-2xl) 0 var(--space-lg);
  text-align: center;
}

.footer-title {
  font-size: 1.3rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: var(--space-sm);
}

.footer-title span {
  color: var(--primary);
}

.footer-desc {
  font-size: 0.85rem;
  max-width: 500px;
  margin: 0 auto var(--space-lg);
  line-height: 1.7;
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: var(--space-lg);
  margin-bottom: var(--space-lg);
  flex-wrap: wrap;
}

.footer-links a {
  color: rgba(255,255,255,0.7);
  font-size: 0.85rem;
  transition: var(--transition-fast);
}

.footer-links a:hover {
  color: var(--primary);
}

.footer-copy {
  font-size: 0.8rem;
  color: rgba(255,255,255,0.4);
  padding-top: var(--space-lg);
  border-top: 1px solid rgba(255,255,255,0.1);
}

/* --- WhatsApp Float Button --- */
.whatsapp-float {
  position: fixed;
  bottom: 24px;
  right: 24px;
  width: 56px;
  height: 56px;
  background: #25D366;
  color: #fff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  box-shadow: 0 4px 16px rgba(37,211,102,0.4);
  z-index: 50;
  transition: var(--transition);
  text-decoration: none;
}

.whatsapp-float:hover {
  transform: scale(1.1);
  box-shadow: 0 6px 24px rgba(37,211,102,0.5);
  color: #fff;
}

/* --- Animations --- */
@keyframes slideUp {
  from {
    opacity: 0;
    transform: translateY(16px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* --- Responsive: Tablet --- */
@media (min-width: 600px) {
  .input-row {
    grid-template-columns: repeat(2, 1fr);
  }

  .hero h1 {
    font-size: 2.2rem;
  }

  .hero-subtitle {
    font-size: 1.1rem;
  }

  .all-results-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* --- Responsive: Desktop --- */
@media (min-width: 900px) {
  .container {
    max-width: 960px;
  }

  .hero h1 {
    font-size: 2.6rem;
  }

  .section-header h2 {
    font-size: 1.8rem;
  }

  .nav-links {
    gap: var(--space-sm);
  }

  .nav-link {
    font-size: 0.9rem;
  }
}

/* --- Responsive: Mobile --- */
@media (max-width: 599px) {
  .nav-links {
    display: none;
  }

  .mobile-menu-btn {
    display: block;
  }

  .hero {
    padding: var(--space-2xl) 0 var(--space-xl);
  }

  .hero h1 {
    font-size: 1.4rem;
  }

  .hero-tools {
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-sm);
  }

  .hero-tool-card {
    padding: var(--space-md) var(--space-sm);
  }

  .hero-tool-icon {
    font-size: 1.5rem;
  }

  .hero-tool-title {
    font-size: 0.75rem;
  }

  .tool-section {
    padding: var(--space-2xl) 0;
  }

  .tool-card {
    padding: var(--space-md);
  }

  .input-row {
    grid-template-columns: 1fr;
  }

  .result-value {
    font-size: 1.8rem;
  }

  .result-row {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-sm);
  }

  .all-results-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .info-section {
    padding: var(--space-md);
  }

  .faq-question {
    padding: var(--space-md);
    font-size: 0.88rem;
  }

  .breakdown-table {
    font-size: 0.82rem;
  }

  .breakdown-table th,
  .breakdown-table td {
    padding: var(--space-xs) var(--space-sm);
  }

  .footer-links {
    flex-direction: column;
    gap: var(--space-sm);
  }

  .whatsapp-float {
    bottom: 16px;
    right: 16px;
    width: 50px;
    height: 50px;
    font-size: 1.4rem;
  }
}

/* --- Utility --- */
.hidden {
  display: none !important;
}

.text-center {
  text-align: center;
}

.mt-md { margin-top: var(--space-md); }
.mt-lg { margin-top: var(--space-lg); }
.mb-md { margin-bottom: var(--space-md); }

/* --- Mobile Touch & Input Fixes --- */

/* Prevent iOS zoom on input focus (font-size must be >= 16px) */
@media (max-width: 599px) {
  .input-field,
  .select-field {
    font-size: 16px; /* Prevents auto-zoom on iOS */
  }
}

/* Remove number input spinners (cleaner look) */
input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button {
  -webkit-appearance: none;
  margin: 0;
}
input[type="number"] {
  -moz-appearance: textfield;
}

/* Safe area for notched phones (iPhone X+) */
@supports (padding: env(safe-area-inset-bottom)) {
  .footer {
    padding-bottom: calc(var(--space-lg) + env(safe-area-inset-bottom));
  }
  .whatsapp-float {
    bottom: calc(24px + env(safe-area-inset-bottom));
  }
}

/* Print styles */
@media print {
  .header, .hero, .whatsapp-float, .share-row, .mobile-menu, .btn-primary {
    display: none !important;
  }
  .result-card {
    border: 2px solid #000;
    break-inside: avoid;
  }
  .tool-section {
    padding: 16px 0;
  }
}