@view-transition {
  navigation: auto;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  padding: 0;
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: linear-gradient(135deg, #f5f7fa 0%, #e2e8f0 100%);
}

/* ===== Header ===== */

.header {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  box-shadow: 0 4px 20px rgba(76, 81, 191, 0.3);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.site-logo {
  height: 40px;
  width: auto;
  display: block;
}

.site-title-link {
  text-decoration: none;
}

.site-title-text {
  color: #ffffff;
  font-size: 1.25rem;
  font-weight: 700;
  white-space: nowrap;
}

.nav-link {
  color: #ffffff;
  text-decoration: none;
  font-weight: 500;
  transition: all 0.25s ease;
  display: inline-block;
}

.nav-link:hover {
  color: #e5e7eb;
  transform: scale(1.05);
}

.main-nav-center {
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
}

/* Dropdown (desktop) */
.dropdown {
  position: relative;
}

.dropdown-toggle {
  background: none;
  border: none;
  color: #ffffff;
  cursor: pointer;
  font-weight: 500;
  transition: color 0.25s ease;
}

.dropdown-toggle:hover {
  color: #e5e7eb;
}

.dropdown-content {
  display: none;
  position: absolute;
  right: 0;
  top: 100%;
  margin-top: 8px;
  min-width: 220px;
  background: #ffffff;
  border-radius: 12px;
  box-shadow: 0 10px 35px rgba(0, 0, 0, 0.16);
  overflow: hidden;
  z-index: 1001;
}

.dropdown.open .dropdown-content {
  display: block;
}

.dropdown-content a {
  display: block;
  padding: 12px 20px;
  color: #374151;
  text-decoration: none;
  font-size: 14px;
  transition: background 0.25s ease, padding-left 0.25s ease;
}

.dropdown-content a:hover {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: #ffffff;
  padding-left: 26px;
}

/* Mobile header controls */
.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  color: #ffffff;
  font-size: 24px;
  cursor: pointer;
}

/* Mobile Nav Overlay */
.mobile-nav-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.45);
  z-index: 900;
}

.mobile-nav-overlay.active {
  display: block;
}

.mobile-nav-panel {
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  margin-top: 64px;
  background: linear-gradient(135deg, #059669 0%, #047857 100%);
  padding: 16px 24px 24px;
  transform: translateY(-100%);
  transition: transform 0.3s ease;
}

.mobile-nav-overlay.active .mobile-nav-panel {
  transform: translateY(0);
}

.mobile-nav-links a {
  display: block;
  color: #ffffff;
  text-decoration: none;
  padding: 10px 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.16);
  font-size: 15px;
}

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

.mobile-nav-links a:hover {
  opacity: 0.9;
}

.mobile-nav-label {
  display: block;
  color: #bbf7d0;
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin: 12px 0 4px;
}

/* ===== Calculator Card ===== */

.calculator-container {
  max-width: 1200px;
  margin: 40px auto;
  padding: 0 20px;
}

.calc-card {
  background: #ffffff;
  border-radius: 20px;
  box-shadow: 0 18px 50px rgba(0, 0, 0, 0.12);
  padding: 40px;
  animation: fadeInUp 0.6s ease-out;
}

.calc-title {
  font-size: 42px;
  font-weight: 700;
  color: #1f2933;
  margin-bottom: 12px;
  text-align: center;
}

.calc-description {
  text-align: center;
  color: #4b5563;
  font-size: 18px;
  margin-bottom: 36px;
  max-width: 800px;
  margin-left: auto;
  margin-right: auto;
}

.input-group {
  margin-bottom: 24px;
  animation: slideIn 0.5s ease-out;
}

.input-group label {
  display: block;
  font-weight: 600;
  color: #2d3748;
  margin-bottom: 8px;
  font-size: 16px;
}

.input-group input {
  width: 100%;
  padding: 14px 18px;
  border: 2px solid #e2e8f0;
  border-radius: 10px;
  font-size: 16px;
  transition: all 0.3s;
  font-family: 'Inter', sans-serif;
}

.input-group input:focus {
  outline: none;
  border-color: #667eea;
  box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.15);
}

.operations-wrapper {
  background: linear-gradient(135deg, #f0fff4 0%, #c6f6d5 100%);
  padding: 24px;
  border-radius: 14px;
  margin-top: 28px;
}

.operations-wrapper h3 {
  color: #22543d;
  font-size: 20px;
  margin-bottom: 8px;
}

.operations-note {
  color: #276749;
  font-size: 14px;
  margin-bottom: 20px;
}

.operations-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 12px;
}

.op-btn {
  background: linear-gradient(135deg, #48bb78 0%, #38a169 100%);
  color: #ffffff;
  border: none;
  padding: 14px;
  border-radius: 10px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.25s ease;
  box-shadow: 0 4px 8px rgba(56, 161, 105, 0.35);
}

.op-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 16px rgba(56, 161, 105, 0.45);
}

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

/* Result box */
.result-box {
  background: linear-gradient(135deg, #f7fafc 0%, #edf2f7 100%);
  border: 2px solid #667eea;
  border-radius: 12px;
  padding: 24px;
  margin-top: 30px;
  min-height: 80px;
  animation: pulse 0.5s ease-out;
}

.result-label {
  font-weight: 600;
  color: #667eea;
  margin-bottom: 8px;
  font-size: 14px;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.result-value {
  font-size: 24px;
  font-weight: 700;
  color: #2d3748;
  word-break: break-all;
  font-family: 'Courier New', monospace;
}

.download-section {
  display: flex;
  gap: 12px;
  margin-top: 20px;
  flex-wrap: wrap;
}

.download-btn {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: #ffffff;
  border: none;
  padding: 10px 20px;
  border-radius: 8px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.25s ease;
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.download-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 14px rgba(102, 126, 234, 0.45);
}

/* ===== Blog Section ===== */

.blog-section {
  max-width: 900px;
  margin: 60px auto;
  padding: 0 20px;
}

.blog-content {
  background: #ffffff;
  border-radius: 18px;
  padding: 50px;
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.1);
  line-height: 1.8;
}

.blog-content h1 {
  color: #1f2933;
  font-size: 34px;
  margin-bottom: 20px;
  font-weight: 700;
}

.blog-content h2 {
  color: #4c51bf;
  font-size: 26px;
  margin-top: 36px;
  margin-bottom: 14px;
  font-weight: 600;
}

.blog-content h3 {
  color: #4a5568;
  font-size: 20px;
  margin-top: 26px;
  margin-bottom: 10px;
  font-weight: 600;
}

.blog-content p {
  color: #4a5568;
  font-size: 16.5px;
  margin-bottom: 18px;
  text-align: justify;
}

.blog-content ul,
.blog-content ol {
  color: #4a5568;
  font-size: 16px;
  margin-bottom: 18px;
  padding-left: 30px;
}

.blog-content li {
  margin-bottom: 8px;
}

.blog-content a {
  color: #2563eb;
  text-decoration: underline;
}

/* Powers table */
.powers-table {
  width: 100%;
  border-collapse: collapse;
  margin: 26px 0;
  background: #ffffff;
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.06);
}

.powers-table th {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: #ffffff;
  padding: 14px 16px;
  text-align: left;
  font-weight: 600;
  font-size: 15px;
}

.powers-table td {
  padding: 12px 16px;
  border-bottom: 1px solid #e2e8f0;
  color: #4a5568;
  font-size: 15px;
}

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

.powers-table tr:hover {
  background-color: #f7fafc;
}

.info-box {
  background: linear-gradient(135deg, #ebf4ff 0%, #e0e7ff 100%);
  border-left: 4px solid #667eea;
  padding: 18px 22px;
  border-radius: 10px;
  margin: 26px 0;
}

.info-box p {
  margin: 0;
  color: #2d3748;
}

/* ===== FAQ Section ===== */

.faq-section {
  max-width: 900px;
  margin: 0 auto 70px;
  padding: 0 20px;
}

.faq-inner {
  background: #ffffff;
  border-radius: 18px;
  padding: 32px 26px;
  box-shadow: 0 10px 32px rgba(0, 0, 0, 0.08);
}

.faq-inner h2 {
  font-size: 28px;
  font-weight: 700;
  margin-bottom: 20px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.faq-item + .faq-item {
  margin-top: 16px;
  padding-top: 14px;
  border-top: 1px solid #e5e7eb;
}

.faq-item h3 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 6px;
  color: #111827;
}

.faq-item p {
  font-size: 15px;
  color: #4b5563;
  margin: 0 0 4px;
}

/* ===== Footer ===== */

.footer {
  background: linear-gradient(135deg, #2d3748 0%, #1a202c 100%);
  color: #ffffff;
  padding: 60px 0 20px;
  margin-top: 80px;
}

.footer-column h3 {
  color: #a3bffa;
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 18px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.footer-column ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.footer-column ul li {
  margin-bottom: 10px;
}

.footer-column ul li a {
  color: #cbd5e0;
  text-decoration: none;
  transition: all 0.25s ease;
}

.footer-column ul li a:hover {
  color: #667eea;
  transform: translateX(4px);
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.16);
  margin-top: 36px;
  padding-top: 26px;
  text-align: center;
  color: #a0aec0;
}

/* ===== Animations ===== */

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

@keyframes slideIn {
  from {
    opacity: 0;
    transform: translateX(-18px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes pulse {
  0%, 100% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.02);
  }
}

/* ===== Responsive ===== */

@media (max-width: 1024px) {
  .main-nav-center {
    position: static;
    transform: none;
  }
}

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

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

  .calc-card {
    padding: 26px 20px 30px;
  }

  .calc-title {
    font-size: 32px;
  }

  .calc-description {
    font-size: 16px;
  }

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

  .blog-content {
    padding: 30px 22px;
  }

  .blog-content h1 {
    font-size: 28px;
  }

  .blog-content h2 {
    font-size: 22px;
  }

  .download-section {
    flex-direction: column;
  }

  .download-btn {
    width: 100%;
    justify-content: center;
  }
@media (max-width: 768px) {
  .main-nav-center {
    display: none !important;
  }
}