/* ===================================
   CalcTools - Main Stylesheet
   Color Scheme: Black & White
   =================================== */

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

:root {
  --primary: #000000;
  --secondary: #ffffff;
  --accent: #222222;
  --gray-100: #f5f5f5;
  --gray-200: #e0e0e0;
  --gray-300: #cccccc;
  --gray-400: #999999;
  --gray-500: #666666;
  --gray-600: #444444;
  --gray-700: #333333;
  --gray-800: #222222;
  --gray-900: #111111;
  --font-main: 'Inter', 'Segoe UI', sans-serif;
  --border-radius: 12px;
  --border-radius-sm: 8px;
  --border-radius-lg: 20px;
  --shadow-sm: 0 2px 8px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 20px rgba(0,0,0,0.12);
  --shadow-lg: 0 8px 40px rgba(0,0,0,0.18);
  --shadow-xl: 0 16px 60px rgba(0,0,0,0.25);
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-fast: all 0.15s ease;
  --max-width: 1200px;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-main);
  color: var(--primary);
  background: var(--secondary);
  line-height: 1.6;
  overflow-x: hidden;
}

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

ul { list-style: none; }

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

/* ===================================
   TYPOGRAPHY
   =================================== */

h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.3;
}

h1 { font-size: clamp(2rem, 5vw, 3.5rem); }
h2 { font-size: clamp(1.5rem, 3.5vw, 2.5rem); }
h3 { font-size: clamp(1.2rem, 2.5vw, 1.8rem); }
h4 { font-size: 1.2rem; }

p { color: var(--gray-600); }

/* ===================================
   LAYOUT UTILITIES
   =================================== */

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.section {
  padding: 80px 0;
}

.section-sm {
  padding: 50px 0;
}

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

.flex { display: flex; }
.flex-center { display: flex; align-items: center; justify-content: center; }
.grid { display: grid; }

/* ===================================
   HEADER / NAVIGATION
   =================================== */

.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--gray-200);
  transition: var(--transition);
}

.site-header.scrolled {
  box-shadow: var(--shadow-md);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 1.5rem;
  max-width: var(--max-width);
  margin: 0 auto;
}

/* Logo */
.logo {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--primary);
  letter-spacing: -0.5px;
}

.logo span {
  display: inline-block;
  background: var(--primary);
  color: var(--secondary);
  padding: 2px 8px;
  border-radius: 6px;
  margin-left: 2px;
}

/* Main Navigation */
.main-nav {
  display: flex;
  align-items: center;
  gap: 2rem;
}

.nav-link {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--gray-700);
  padding: 0.4rem 0;
  position: relative;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--primary);
  transition: var(--transition);
}

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

.nav-link:hover::after,
.nav-link.active::after {
  width: 100%;
}

/* Dropdown */
.nav-dropdown {
  position: relative;
}

.dropdown-toggle {
  display: flex;
  align-items: center;
  gap: 0.3rem;
  cursor: pointer;
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--gray-700);
  padding: 0.4rem 0;
  border: none;
  background: none;
  font-family: inherit;
  transition: var(--transition-fast);
}

.dropdown-toggle:hover {
  color: var(--primary);
}

.dropdown-toggle svg {
  transition: transform 0.3s ease;
}

.nav-dropdown:hover .dropdown-toggle svg {
  transform: rotate(180deg);
}

.dropdown-menu {
  position: absolute;
  top: calc(100% + 0.5rem);
  left: 50%;
  transform: translateX(-50%);
  background: white;
  border: 1px solid var(--gray-200);
  border-radius: var(--border-radius);
  box-shadow: var(--shadow-xl);
  min-width: 500px;
  padding: 1rem;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.25rem;
  opacity: 0;
  visibility: hidden;
  transform: translateX(-50%) translateY(-10px);
  transition: all 0.25s ease;
  pointer-events: none;
}

.nav-dropdown:hover .dropdown-menu {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(0);
  pointer-events: all;
}

.dropdown-item {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.6rem 0.8rem;
  border-radius: var(--border-radius-sm);
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--gray-700);
  transition: var(--transition-fast);
}

.dropdown-item:hover {
  background: var(--gray-100);
  color: var(--primary);
}

.dropdown-item .item-icon {
  font-size: 1.1rem;
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--gray-100);
  border-radius: 6px;
  flex-shrink: 0;
}

/* Hamburger Menu */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 4px;
  background: none;
  border: none;
}

.hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--primary);
  border-radius: 2px;
  transition: var(--transition);
}

.hamburger.active span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.hamburger.active span:nth-child(2) {
  opacity: 0;
}
.hamburger.active span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* Mobile Nav */
.mobile-nav {
  display: none;
  background: white;
  border-top: 1px solid var(--gray-200);
  padding: 1rem 1.5rem;
  flex-direction: column;
  gap: 0.5rem;
}

.mobile-nav.open {
  display: flex;
}

.mobile-nav a {
  padding: 0.6rem 0;
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--gray-700);
  border-bottom: 1px solid var(--gray-100);
}

.mobile-nav a:last-child {
  border-bottom: none;
}

.mobile-nav a:hover {
  color: var(--primary);
}

/* ===================================
   AD BANNERS
   =================================== */

.ad-banner {
  background: var(--gray-100);
  border: 1px dashed var(--gray-300);
  border-radius: var(--border-radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.8rem;
  color: var(--gray-400);
  font-style: italic;
  text-align: center;
  overflow: hidden;
}

.ad-banner-header {
  width: 100%;
  height: 90px;
  margin: 0.5rem 0;
}

.ad-banner-leaderboard {
  width: 100%;
  height: 90px;
  margin: 2rem 0;
}

.ad-banner-rectangle {
  width: 100%;
  max-width: 336px;
  height: 280px;
  margin: 0 auto;
}

.ad-banner-sidebar {
  width: 160px;
  height: 600px;
}

.ad-label {
  font-size: 0.65rem;
  color: var(--gray-400);
  text-align: center;
  display: block;
  margin-bottom: 2px;
  letter-spacing: 0.5px;
  text-transform: uppercase;
}

/* ===================================
   HERO SECTION
   =================================== */

.hero {
  position: relative;
  min-height: 90vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  background: var(--primary);
  color: var(--secondary);
}

#particles-canvas {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
}

.hero-content {
  position: relative;
  z-index: 2;
  text-align: center;
  max-width: 800px;
  padding: 2rem 1.5rem;
  animation: fadeInUp 0.8s ease forwards;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  background: rgba(255,255,255,0.1);
  border: 1px solid rgba(255,255,255,0.2);
  color: rgba(255,255,255,0.9);
  padding: 0.4rem 1rem;
  border-radius: 50px;
  font-size: 0.85rem;
  font-weight: 500;
  margin-bottom: 1.5rem;
}

.hero h1 {
  color: var(--secondary);
  margin-bottom: 1.2rem;
  font-size: clamp(2.2rem, 5vw, 4rem);
  font-weight: 800;
  letter-spacing: -1px;
}

.hero h1 .highlight {
  position: relative;
  display: inline-block;
}

.hero h1 .highlight::after {
  content: '';
  position: absolute;
  bottom: 4px;
  left: 0;
  width: 100%;
  height: 4px;
  background: rgba(255,255,255,0.4);
  border-radius: 2px;
}

.hero p {
  color: rgba(255,255,255,0.75);
  font-size: clamp(1rem, 2vw, 1.2rem);
  max-width: 600px;
  margin: 0 auto 2.5rem;
}

.hero-btns {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

.hero-stats {
  display: flex;
  gap: 3rem;
  justify-content: center;
  margin-top: 4rem;
  padding-top: 2rem;
  border-top: 1px solid rgba(255,255,255,0.15);
}

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

.stat-number {
  display: block;
  font-size: 2rem;
  font-weight: 800;
  color: white;
  line-height: 1;
}

.stat-label {
  font-size: 0.8rem;
  color: rgba(255,255,255,0.6);
  margin-top: 0.3rem;
}

/* ===================================
   BUTTONS
   =================================== */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.8rem 2rem;
  border-radius: 50px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  border: 2px solid transparent;
  transition: var(--transition);
  font-family: inherit;
  text-decoration: none;
  white-space: nowrap;
}

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

.btn-primary:hover {
  background: transparent;
  color: var(--secondary);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(255,255,255,0.25);
}

.btn-outline {
  background: transparent;
  color: var(--secondary);
  border-color: rgba(255,255,255,0.5);
}

.btn-outline:hover {
  background: rgba(255,255,255,0.1);
  border-color: var(--secondary);
  transform: translateY(-2px);
}

.btn-dark {
  background: var(--primary);
  color: var(--secondary);
  border-color: var(--primary);
}

.btn-dark:hover {
  background: var(--gray-800);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

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

.btn-dark-outline:hover {
  background: var(--primary);
  color: var(--secondary);
  transform: translateY(-2px);
}

.btn-sm {
  padding: 0.5rem 1.2rem;
  font-size: 0.85rem;
}

.btn-lg {
  padding: 1rem 2.5rem;
  font-size: 1.05rem;
}

.btn-black {
  background: #000;
  color: #fff;
  border-color: #000;
}

.btn-black:hover {
  background: #333;
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

/* ===================================
   SECTION HEADERS
   =================================== */

.section-header {
  text-align: center;
  margin-bottom: 3.5rem;
}

.section-tag {
  display: inline-block;
  background: var(--gray-100);
  color: var(--gray-600);
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  padding: 0.35rem 1rem;
  border-radius: 50px;
  margin-bottom: 1rem;
}

.section-header h2 {
  margin-bottom: 1rem;
  color: var(--primary);
}

.section-header p {
  max-width: 600px;
  margin: 0 auto;
  font-size: 1.05rem;
}

/* ===================================
   TOOL CARDS
   =================================== */

.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1.5rem;
}

.tool-card {
  background: white;
  border: 1px solid var(--gray-200);
  border-radius: var(--border-radius);
  padding: 1.8rem;
  transition: var(--transition);
  cursor: pointer;
  text-decoration: none;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.tool-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-xl);
  border-color: var(--gray-300);
}

.tool-icon {
  width: 56px;
  height: 56px;
  background: var(--gray-100);
  border-radius: var(--border-radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  transition: var(--transition);
}

.tool-card:hover .tool-icon {
  background: var(--primary);
  transform: scale(1.1);
}

.tool-card:hover .tool-icon span {
  filter: invert(1);
}

.tool-card h3 {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--primary);
  margin: 0;
}

.tool-card p {
  font-size: 0.88rem;
  color: var(--gray-500);
  flex-grow: 1;
  margin: 0;
}

.tool-card .card-link {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--primary);
  transition: var(--transition-fast);
}

.tool-card:hover .card-link {
  gap: 0.6rem;
}

/* ===================================
   FEATURES SECTION
   =================================== */

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.5rem;
}

.feature-card {
  text-align: center;
  padding: 2rem 1.5rem;
  border: 1px solid var(--gray-200);
  border-radius: var(--border-radius);
  transition: var(--transition);
}

.feature-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-4px);
}

.feature-icon {
  width: 64px;
  height: 64px;
  background: var(--gray-100);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.8rem;
  margin: 0 auto 1rem;
  transition: var(--transition);
}

.feature-card:hover .feature-icon {
  background: var(--primary);
}

.feature-card:hover .feature-icon span {
  filter: invert(1);
}

.feature-card h3 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.feature-card p {
  font-size: 0.88rem;
}

/* ===================================
   SEO CONTENT SECTION
   =================================== */

.seo-section {
  background: var(--gray-100);
}

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

.seo-content h2 {
  margin-bottom: 1.5rem;
  color: var(--primary);
}

.seo-content h3 {
  font-size: 1.2rem;
  margin: 1.8rem 0 0.8rem;
  color: var(--primary);
}

.seo-content p {
  margin-bottom: 1rem;
  color: var(--gray-600);
  line-height: 1.8;
}

.seo-content ul {
  list-style: disc;
  padding-left: 1.5rem;
  margin-bottom: 1rem;
}

.seo-content ul li {
  color: var(--gray-600);
  margin-bottom: 0.4rem;
  line-height: 1.7;
}

/* ===================================
   CTA SECTION
   =================================== */

.cta-section {
  background: var(--primary);
  color: var(--secondary);
  text-align: center;
  padding: 80px 0;
}

.cta-section h2 {
  color: var(--secondary);
  margin-bottom: 1rem;
}

.cta-section p {
  color: rgba(255,255,255,0.7);
  max-width: 550px;
  margin: 0 auto 2rem;
  font-size: 1.05rem;
}

/* ===================================
   TOOL PAGE LAYOUT
   =================================== */

.tool-hero {
  background: var(--primary);
  color: white;
  padding: 4rem 0 3rem;
  text-align: center;
}

.tool-hero h1 {
  color: white;
  margin-bottom: 0.8rem;
  font-size: clamp(1.8rem, 4vw, 3rem);
}

.tool-hero p {
  color: rgba(255,255,255,0.75);
  max-width: 600px;
  margin: 0 auto;
  font-size: 1.05rem;
}

.tool-breadcrumb {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.85rem;
  color: rgba(255,255,255,0.6);
  justify-content: center;
  margin-bottom: 1.5rem;
}

.tool-breadcrumb a {
  color: rgba(255,255,255,0.7);
}

.tool-breadcrumb a:hover {
  color: white;
}

.tool-layout {
  padding: 3rem 0;
}

.tool-main {
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: 2rem;
  align-items: start;
}

.tool-sidebar {
  position: sticky;
  top: 100px;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

/* Calculator Box */
.calculator-box {
  background: white;
  border: 1px solid var(--gray-200);
  border-radius: var(--border-radius-lg);
  padding: 2rem;
  margin-bottom: 2rem;
  box-shadow: var(--shadow-sm);
}

.calculator-box h2 {
  font-size: 1.3rem;
  margin-bottom: 1.5rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--gray-200);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

/* Form Styles */
.calc-form {
  display: flex;
  flex-direction: column;
  gap: 1.2rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

.form-group label {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--gray-700);
}

.form-group input,
.form-group select {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 1.5px solid var(--gray-200);
  border-radius: var(--border-radius-sm);
  font-size: 0.95rem;
  font-family: inherit;
  color: var(--primary);
  background: var(--secondary);
  transition: var(--transition-fast);
  outline: none;
}

.form-group input:focus,
.form-group select:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(0,0,0,0.08);
}

.form-group input.error {
  border-color: #dc2626;
}

.form-group .error-msg {
  font-size: 0.8rem;
  color: #dc2626;
  display: none;
}

.form-group .error-msg.show {
  display: block;
}

.input-hint {
  font-size: 0.78rem;
  color: var(--gray-400);
}

/* Result Box */
.result-box {
  background: var(--gray-100);
  border-radius: var(--border-radius);
  padding: 1.5rem;
  margin-top: 1.5rem;
  display: none;
  animation: fadeIn 0.4s ease;
}

.result-box.show {
  display: block;
}

.result-box h3 {
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--gray-500);
  margin-bottom: 1rem;
  font-weight: 600;
}

.result-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

.result-item {
  background: white;
  border-radius: var(--border-radius-sm);
  padding: 1rem;
  text-align: center;
  border: 1px solid var(--gray-200);
}

.result-item.primary {
  grid-column: span 2;
  background: var(--primary);
  color: white;
  border-color: var(--primary);
}

.result-item .result-label {
  font-size: 0.78rem;
  color: var(--gray-500);
  display: block;
  margin-bottom: 0.3rem;
}

.result-item.primary .result-label {
  color: rgba(255,255,255,0.7);
}

.result-item .result-value {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--primary);
  display: block;
  line-height: 1.2;
}

.result-item.primary .result-value {
  color: white;
  font-size: 2rem;
}

.calc-actions {
  display: flex;
  gap: 1rem;
  margin-top: 1rem;
}

/* Radio Group */
.radio-group {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

.radio-label {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  cursor: pointer;
  font-size: 0.9rem;
  color: var(--gray-700);
  padding: 0.5rem 1rem;
  border: 1.5px solid var(--gray-200);
  border-radius: 50px;
  transition: var(--transition-fast);
}

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

.radio-label input {
  display: none;
}

/* Range Input */
.range-container {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.range-container input[type="range"] {
  flex: 1;
  appearance: none;
  height: 4px;
  background: var(--gray-200);
  border-radius: 2px;
  outline: none;
  border: none;
  padding: 0;
}

.range-container input[type="range"]::-webkit-slider-thumb {
  appearance: none;
  width: 18px;
  height: 18px;
  background: var(--primary);
  border-radius: 50%;
  cursor: pointer;
}

.range-value {
  min-width: 60px;
  text-align: center;
  font-weight: 700;
  font-size: 0.95rem;
  padding: 0.3rem 0.6rem;
  background: var(--gray-100);
  border-radius: 6px;
}

/* ===================================
   SEO CONTENT ON TOOL PAGES
   =================================== */

.tool-seo-content {
  background: white;
  border: 1px solid var(--gray-200);
  border-radius: var(--border-radius-lg);
  padding: 2rem;
  margin-bottom: 2rem;
}

.tool-seo-content h2 {
  font-size: 1.4rem;
  margin-bottom: 1.2rem;
  padding-bottom: 0.8rem;
  border-bottom: 1px solid var(--gray-200);
}

.tool-seo-content h3 {
  font-size: 1.1rem;
  margin: 1.5rem 0 0.6rem;
  color: var(--primary);
}

.tool-seo-content p {
  margin-bottom: 0.9rem;
  line-height: 1.8;
  color: var(--gray-600);
}

.tool-seo-content ul,
.tool-seo-content ol {
  padding-left: 1.5rem;
  margin-bottom: 1rem;
}

.tool-seo-content ul { list-style: disc; }
.tool-seo-content ol { list-style: decimal; }

.tool-seo-content li {
  color: var(--gray-600);
  margin-bottom: 0.4rem;
  line-height: 1.7;
}

.formula-box {
  background: var(--gray-100);
  border-left: 4px solid var(--primary);
  border-radius: 0 var(--border-radius-sm) var(--border-radius-sm) 0;
  padding: 1rem 1.5rem;
  margin: 1rem 0;
  font-family: 'Courier New', monospace;
  font-size: 0.9rem;
  color: var(--gray-800);
}

/* ===================================
   FAQ SECTION
   =================================== */

.faq-section {
  background: white;
  border: 1px solid var(--gray-200);
  border-radius: var(--border-radius-lg);
  padding: 2rem;
  margin-bottom: 2rem;
}

.faq-section h2 {
  font-size: 1.4rem;
  margin-bottom: 1.5rem;
  padding-bottom: 0.8rem;
  border-bottom: 1px solid var(--gray-200);
}

.faq-item {
  border-bottom: 1px solid var(--gray-100);
}

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

.faq-question {
  width: 100%;
  background: none;
  border: none;
  text-align: left;
  padding: 1rem 0;
  font-family: inherit;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--primary);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  transition: var(--transition-fast);
}

.faq-question:hover {
  color: var(--gray-600);
}

.faq-icon {
  width: 24px;
  height: 24px;
  background: var(--gray-100);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  font-size: 1rem;
  font-weight: 700;
  transition: var(--transition);
}

.faq-item.active .faq-icon {
  background: var(--primary);
  color: white;
  transform: rotate(45deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease, padding 0.35s ease;
}

.faq-item.active .faq-answer {
  max-height: 500px;
  padding-bottom: 1rem;
}

.faq-answer p {
  font-size: 0.9rem;
  color: var(--gray-600);
  line-height: 1.7;
}

/* ===================================
   RELATED TOOLS
   =================================== */

.related-tools {
  background: var(--gray-100);
  border-radius: var(--border-radius-lg);
  padding: 1.5rem;
}

.related-tools h3 {
  font-size: 1rem;
  margin-bottom: 1rem;
  color: var(--primary);
}

.related-tools-list {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.related-tool-link {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.6rem 0.8rem;
  background: white;
  border-radius: var(--border-radius-sm);
  border: 1px solid var(--gray-200);
  font-size: 0.88rem;
  color: var(--gray-700);
  font-weight: 500;
  transition: var(--transition-fast);
}

.related-tool-link:hover {
  background: var(--primary);
  color: white;
  border-color: var(--primary);
}

.related-tool-link span {
  font-size: 1rem;
}

/* ===================================
   FOOTER
   =================================== */

.site-footer {
  background: var(--gray-900);
  color: rgba(255,255,255,0.8);
  padding: 60px 0 0;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1fr;
  gap: 2.5rem;
  padding-bottom: 2.5rem;
  border-bottom: 1px solid rgba(255,255,255,0.1);
}

.footer-brand .logo {
  color: white;
  margin-bottom: 1rem;
  display: block;
}

.footer-brand .logo span {
  background: white;
  color: var(--gray-900);
}

.footer-brand p {
  color: rgba(255,255,255,0.6);
  font-size: 0.9rem;
  line-height: 1.7;
  margin-bottom: 1.2rem;
}

.social-links {
  display: flex;
  gap: 0.6rem;
}

.social-link {
  width: 36px;
  height: 36px;
  background: rgba(255,255,255,0.1);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: rgba(255,255,255,0.7);
  font-size: 0.9rem;
  transition: var(--transition-fast);
}

.social-link:hover {
  background: white;
  color: var(--gray-900);
}

.footer-col h4 {
  font-size: 0.9rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: white;
  margin-bottom: 1.2rem;
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.footer-links a {
  font-size: 0.88rem;
  color: rgba(255,255,255,0.6);
  transition: var(--transition-fast);
}

.footer-links a:hover {
  color: white;
  padding-left: 4px;
}

.footer-bottom {
  padding: 1.5rem 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}

.footer-bottom p {
  font-size: 0.85rem;
  color: rgba(255,255,255,0.5);
}

.footer-bottom-links {
  display: flex;
  gap: 1.5rem;
}

.footer-bottom-links a {
  font-size: 0.85rem;
  color: rgba(255,255,255,0.5);
}

.footer-bottom-links a:hover {
  color: white;
}

/* ===================================
   PAGE HERO (Inner Pages)
   =================================== */

.page-hero {
  background: var(--primary);
  color: white;
  padding: 4rem 0;
  text-align: center;
}

.page-hero h1 {
  color: white;
  margin-bottom: 0.8rem;
}

.page-hero p {
  color: rgba(255,255,255,0.7);
  max-width: 600px;
  margin: 0 auto;
}

/* ===================================
   CONTACT PAGE
   =================================== */

.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 3rem;
  align-items: start;
}

.contact-info {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.contact-item {
  display: flex;
  gap: 1rem;
  align-items: flex-start;
}

.contact-icon {
  width: 44px;
  height: 44px;
  background: var(--gray-100);
  border-radius: var(--border-radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  flex-shrink: 0;
}

.contact-item h4 {
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 0.3rem;
}

.contact-item p {
  font-size: 0.9rem;
}

.contact-form-box {
  background: white;
  border: 1px solid var(--gray-200);
  border-radius: var(--border-radius-lg);
  padding: 2rem;
}

.contact-form {
  display: flex;
  flex-direction: column;
  gap: 1.2rem;
}

.contact-form textarea {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 1.5px solid var(--gray-200);
  border-radius: var(--border-radius-sm);
  font-size: 0.95rem;
  font-family: inherit;
  color: var(--primary);
  resize: vertical;
  min-height: 130px;
  outline: none;
  transition: var(--transition-fast);
}

.contact-form textarea:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(0,0,0,0.08);
}

/* ===================================
   ABOUT PAGE
   =================================== */

.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: center;
}

.about-img {
  background: var(--gray-100);
  border-radius: var(--border-radius-lg);
  aspect-ratio: 4/3;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 5rem;
}

.about-content h2 {
  margin-bottom: 1rem;
}

.about-content p {
  margin-bottom: 1rem;
  line-height: 1.8;
}

.team-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1.5rem;
}

.team-card {
  text-align: center;
  padding: 2rem 1.5rem;
  border: 1px solid var(--gray-200);
  border-radius: var(--border-radius);
  transition: var(--transition);
}

.team-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-4px);
}

.team-avatar {
  width: 80px;
  height: 80px;
  background: var(--gray-200);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2.5rem;
  margin: 0 auto 1rem;
}

.team-card h4 {
  margin-bottom: 0.3rem;
}

.team-card p {
  font-size: 0.85rem;
}

/* ===================================
   LEGAL PAGES
   =================================== */

.legal-content {
  max-width: 860px;
  margin: 0 auto;
  padding: 3rem 1.5rem;
}

.legal-content h1 {
  font-size: 2rem;
  margin-bottom: 0.5rem;
}

.legal-content .last-updated {
  color: var(--gray-400);
  font-size: 0.88rem;
  margin-bottom: 2rem;
}

.legal-content h2 {
  font-size: 1.3rem;
  margin: 2rem 0 0.8rem;
  color: var(--primary);
}

.legal-content h3 {
  font-size: 1.1rem;
  margin: 1.5rem 0 0.6rem;
}

.legal-content p {
  margin-bottom: 1rem;
  line-height: 1.8;
}

.legal-content ul {
  list-style: disc;
  padding-left: 1.5rem;
  margin-bottom: 1rem;
}

.legal-content ul li {
  margin-bottom: 0.4rem;
  line-height: 1.7;
  color: var(--gray-600);
}

/* ===================================
   ANIMATIONS
   =================================== */

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

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

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

@keyframes slideInLeft {
  from { opacity: 0; transform: translateX(-30px); }
  to { opacity: 1; transform: translateX(0); }
}

@keyframes scaleIn {
  from { opacity: 0; transform: scale(0.9); }
  to { opacity: 1; transform: scale(1); }
}

.animate-fade-up {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

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

.animate-delay-1 { transition-delay: 0.1s; }
.animate-delay-2 { transition-delay: 0.2s; }
.animate-delay-3 { transition-delay: 0.3s; }
.animate-delay-4 { transition-delay: 0.4s; }

/* ===================================
   RESPONSIVE DESIGN
   =================================== */

@media (max-width: 1024px) {
  .tool-main {
    grid-template-columns: 1fr;
  }

  .tool-sidebar {
    position: static;
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
  }

  .contact-grid {
    grid-template-columns: 1fr;
  }

  .about-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .main-nav {
    display: none;
  }

  .hamburger {
    display: flex;
  }

  .hero-stats {
    gap: 1.5rem;
  }

  .stat-number {
    font-size: 1.5rem;
  }

  .tools-grid {
    grid-template-columns: 1fr 1fr;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

  .result-grid {
    grid-template-columns: 1fr;
  }

  .result-item.primary {
    grid-column: span 1;
  }

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

  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }

  .hero-stats {
    flex-direction: column;
    gap: 1rem;
    margin-top: 2rem;
  }
}

@media (max-width: 480px) {
  .tools-grid {
    grid-template-columns: 1fr;
  }

  .hero h1 {
    font-size: 2rem;
  }

  .calc-actions {
    flex-direction: column;
  }

  .section {
    padding: 50px 0;
  }
}

/* ===================================
   UTILITY CLASSES
   =================================== */

.d-none { display: none; }
.d-block { display: block; }
.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }
.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }
.py-2 { padding-top: 1rem; padding-bottom: 1rem; }

.text-muted { color: var(--gray-400); }
.text-sm { font-size: 0.85rem; }
.fw-bold { font-weight: 700; }

.divider {
  border: none;
  border-top: 1px solid var(--gray-200);
  margin: 1.5rem 0;
}

/* Notification Toast */
.toast {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  background: var(--primary);
  color: white;
  padding: 0.8rem 1.5rem;
  border-radius: var(--border-radius);
  font-size: 0.9rem;
  box-shadow: var(--shadow-lg);
  z-index: 9999;
  opacity: 0;
  transform: translateY(20px);
  transition: var(--transition);
  pointer-events: none;
}

.toast.show {
  opacity: 1;
  transform: translateY(0);
}