/* CalcHub - Professional Calculator Hub */
:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --primary-light: #3b82f6;
  --secondary: #64748b;
  --success: #10b981;
  --warning: #f59e0b;
  --danger: #ef4444;
  --bg: #f8fafc;
  --bg-card: #ffffff;
  --text: #1e293b;
  --text-muted: #64748b;
  --border: #e2e8f0;
  --shadow: 0 1px 3px rgba(0,0,0,0.1), 0 1px 2px rgba(0,0,0,0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.1), 0 4px 6px -2px rgba(0,0,0,0.05);
  --radius: 12px;
  --radius-sm: 8px;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
}

/* Header */
.header {
  background: var(--bg-card);
  border-bottom: 1px solid var(--border);
  padding: 1rem 0;
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-content {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  text-decoration: none;
  color: var(--text);
  font-weight: 700;
  font-size: 1.5rem;
}

.logo-icon {
  width: 40px;
  height: 40px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 1.25rem;
}

.nav {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.nav a {
  text-decoration: none;
  color: var(--text-muted);
  padding: 0.5rem 1rem;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 500;
  transition: all 0.2s;
}

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

/* Mobile menu */
.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--text);
}

@media (max-width: 768px) {
  .mobile-menu-btn { display: block; }
  .nav {
    display: none;
    width: 100%;
    flex-direction: column;
  }
  .nav.open { display: flex; }
}

/* Main Content */
.main {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem 1.5rem;
}

/* Hero Section */
.hero {
  text-align: center;
  padding: 3rem 1rem;
  margin-bottom: 2rem;
}

.hero h1 {
  font-size: 2.5rem;
  font-weight: 800;
  margin-bottom: 1rem;
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero p {
  color: var(--text-muted);
  font-size: 1.1rem;
  max-width: 600px;
  margin: 0 auto;
}

/* Categories */
.category-section {
  margin-bottom: 3rem;
}

.category-title {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 1.25rem;
  color: var(--text);
}

.category-icon {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
}

.category-icon.finance { background: #dbeafe; color: #2563eb; }
.category-icon.math { background: #dcfce7; color: #16a34a; }
.category-icon.health { background: #fce7f3; color: #db2777; }
.category-icon.shopping { background: #fef3c7; color: #d97706; }
.category-icon.time { background: #e0e7ff; color: #4f46e5; }

/* Calculator Grid */
.calc-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.25rem;
}

.calc-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  text-decoration: none;
  color: var(--text);
  transition: all 0.2s;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

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

.calc-card-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  background: var(--bg);
}

.calc-card h3 {
  font-size: 1.1rem;
  font-weight: 600;
}

.calc-card p {
  color: var(--text-muted);
  font-size: 0.9rem;
  line-height: 1.5;
}

/* Calculator Page Layout */
.calc-page {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
}

@media (min-width: 900px) {
  .calc-page {
    grid-template-columns: 2fr 1fr;
  }
}

.calc-container {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem;
  box-shadow: var(--shadow);
}

.calc-header {
  margin-bottom: 1.5rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--border);
}

.calc-header h1 {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.calc-header p {
  color: var(--text-muted);
}

/* Form Elements */
.form-group {
  margin-bottom: 1.25rem;
}

.form-label {
  display: block;
  font-weight: 500;
  margin-bottom: 0.5rem;
  font-size: 0.9rem;
}

.form-input, .form-select {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 1rem;
  transition: all 0.2s;
  background: var(--bg-card);
}

.form-input:focus, .form-select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.input-group {
  display: flex;
  gap: 0.5rem;
}

.input-group .form-input {
  flex: 1;
}

.input-addon {
  padding: 0.75rem 1rem;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-weight: 500;
  color: var(--text-muted);
  display: flex;
  align-items: center;
}

/* Buttons */
.btn {
  padding: 0.75rem 1.5rem;
  border: none;
  border-radius: var(--radius-sm);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  color: white;
}

.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

.btn-secondary {
  background: var(--bg);
  color: var(--text);
  border: 1px solid var(--border);
}

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

.btn-block {
  width: 100%;
}

/* Result Display */
.result-box {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  color: white;
  padding: 1.5rem;
  border-radius: var(--radius);
  margin-top: 1.5rem;
  text-align: center;
}

.result-label {
  font-size: 0.9rem;
  opacity: 0.9;
  margin-bottom: 0.5rem;
}

.result-value {
  font-size: 2rem;
  font-weight: 700;
}

.result-secondary {
  font-size: 1rem;
  opacity: 0.9;
  margin-top: 0.5rem;
}

/* Multiple Results */
.results-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 1rem;
  margin-top: 1.5rem;
}

.result-card {
  background: var(--bg);
  padding: 1rem;
  border-radius: var(--radius-sm);
  text-align: center;
}

.result-card-label {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 0.25rem;
}

.result-card-value {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--primary);
}

/* Sidebar */
.sidebar {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.sidebar-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
}

.sidebar-card h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

/* Ad Placeholder */
.ad-placeholder {
  background: linear-gradient(135deg, #f1f5f9 0%, #e2e8f0 100%);
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  padding: 2rem;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.9rem;
}

/* Related Calculators */
.related-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.related-link {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.75rem;
  background: var(--bg);
  border-radius: var(--radius-sm);
  text-decoration: none;
  color: var(--text);
  font-size: 0.9rem;
  transition: all 0.2s;
}

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

.related-icon {
  font-size: 1.1rem;
}

/* Tabs */
.tabs {
  display: flex;
  gap: 0.25rem;
  background: var(--bg);
  padding: 0.25rem;
  border-radius: var(--radius-sm);
  margin-bottom: 1.5rem;
}

.tab {
  flex: 1;
  padding: 0.75rem 1rem;
  background: transparent;
  border: none;
  border-radius: 6px;
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s;
  color: var(--text-muted);
}

.tab.active {
  background: var(--bg-card);
  color: var(--primary);
  box-shadow: var(--shadow);
}

.tab-content {
  display: none;
}

.tab-content.active {
  display: block;
}

/* Tables */
.data-table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 1rem;
  font-size: 0.9rem;
}

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

.data-table th {
  background: var(--bg);
  font-weight: 600;
}

.data-table tr:hover td {
  background: var(--bg);
}

/* Footer */
.footer {
  background: var(--bg-card);
  border-top: 1px solid var(--border);
  padding: 3rem 0 2rem;
  margin-top: 4rem;
}

.footer-content {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 2rem;
}

.footer-section h4 {
  font-weight: 600;
  margin-bottom: 1rem;
}

.footer-links {
  list-style: none;
}

.footer-links li {
  margin-bottom: 0.5rem;
}

.footer-links a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.9rem;
  transition: color 0.2s;
}

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

.footer-bottom {
  max-width: 1200px;
  margin: 2rem auto 0;
  padding: 1.5rem 1.5rem 0;
  border-top: 1px solid var(--border);
  text-align: center;
  color: var(--text-muted);
  font-size: 0.9rem;
}

/* Breadcrumb */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
  font-size: 0.9rem;
}

.breadcrumb a {
  color: var(--text-muted);
  text-decoration: none;
}

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

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

/* Info Box */
.info-box {
  background: #eff6ff;
  border: 1px solid #bfdbfe;
  border-radius: var(--radius-sm);
  padding: 1rem;
  margin-top: 1.5rem;
  font-size: 0.9rem;
  color: #1e40af;
}

.info-box h4 {
  font-weight: 600;
  margin-bottom: 0.5rem;
}

/* Range Slider */
.range-container {
  position: relative;
}

.range-input {
  width: 100%;
  height: 8px;
  background: var(--border);
  border-radius: 4px;
  outline: none;
  -webkit-appearance: none;
}

.range-input::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 20px;
  height: 20px;
  background: var(--primary);
  border-radius: 50%;
  cursor: pointer;
}

.range-value {
  text-align: center;
  font-weight: 600;
  margin-top: 0.5rem;
  color: var(--primary);
}

/* Animations */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.animate-in {
  animation: fadeIn 0.3s ease-out;
}

/* Utility Classes */
.text-center { text-align: center; }
.text-muted { color: var(--text-muted); }
.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.hidden { display: none; }