:root {
  --bg-900: #0a0f1a; /* very dark edge */
  --bg-800: #121a2c; /* dark */
  --bg-700: #1b2742; /* less dark center */
  --text-100: #f3f5f9;
  --text-300: #c9d3ea;
  --primary-500: #5b8cff;
  --primary-600: #3f73ff;
  --border-700: #233253;
  /* Light theme surface for main content */
  --light-bg: #ffffff;
  --light-card: #ffffff;
  --light-text: #0b1220;
  --light-muted: #475569;
  --light-border: #e2e8f0;
}

* { box-sizing: border-box; }
html, body { 
  height: 100%; 
  margin: 0;
}
body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  font-family: 'Inter', system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  color: var(--light-text);
  background: var(--light-bg);
}

main {
  flex: 1 0 auto;
}

.container {
  width: 100%;
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 16px;
}

@media (min-width: 768px) {
  .container {
    padding: 0 20px;
  }
}

/* Tool pages container */
.tool-page-container {
  padding: 24px 16px 56px 16px;
}

.tool-page-container > h1 {
  font-size: 24px;
  line-height: 1.3;
  margin-bottom: 12px;
  padding: 0 4px;
}

.tool-page-container > .subtitle {
  padding: 0 4px;
}

@media (min-width: 768px) {
  .tool-page-container {
    padding: 32px 20px 56px 20px;
  }
  
  .tool-page-container > h1 {
    font-size: 36px;
    padding: 0;
  }
  
  .tool-page-container > .subtitle {
    padding: 0;
  }
}

/* View routing system */
.view {
  display: none;
}

.view.active {
  display: block;
}

/* Header with dark edges and softer middle */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  border-bottom: 1px solid var(--border-700);
  background: radial-gradient(800px 160px at 50% 50%,
              #1e2a44 0%, #141c2e 60%, #0b1221 100%);
  flex-shrink: 0;
}
.header-inner {
  display: flex;
  align-items: center;
  gap: 12px;
  height: 64px;
  padding: 0 16px;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--text-100);
  text-decoration: none;
  font-weight: 700;
  flex-shrink: 0;
}
.brand-mark {
  width: 28px;
  height: 28px;
  display: inline-block;
  object-fit: contain;
}
.brand-name { font-size: 18px; letter-spacing: 0.2px; }

.main-nav {
  margin-left: 12px;
  display: none;
  gap: 18px;
  transition: all 0.3s ease;
}
.main-nav a {
  color: var(--text-300);
  text-decoration: none;
  font-weight: 600;
  font-size: 16px;
}
.main-nav a:hover { color: var(--text-100); }

.header-cta {
  margin-left: auto;
  display: none;
  gap: 12px;
  align-items: center;
  transition: all 0.3s ease;
}

/* Mobile menu styles */
@media (max-width: 899px) {
  .site-header {
    position: relative;
  }

  /* Mobile menu container */
  .main-nav {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    width: 280px;
    max-width: 85vw;
    background: linear-gradient(180deg, #1a2438 0%, #0f1623 100%);
    transform: translateX(100%);
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    z-index: 1000;
    box-shadow: -4px 0 24px rgba(0, 0, 0, 0.5);
    overflow-y: auto;
    margin-left: 0;
  }

  .main-nav[data-open] {
    display: flex;
    flex-direction: column;
    transform: translateX(0);
    padding: 70px 0 20px 0;
    gap: 4px;
  }

  /* Close button for mobile menu */
  .mobile-menu-close {
    position: absolute;
    top: 20px;
    right: 20px;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    color: var(--text-100);
    background: rgba(255, 255, 255, 0.1);
    border: none;
    border-radius: 50%;
    cursor: pointer;
    transition: all 0.2s;
    z-index: 10;
  }

  .mobile-menu-close:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: rotate(90deg);
  }
  
  .main-nav[data-open] a {
    padding: 16px 24px;
    border-radius: 0;
    transition: background 0.2s;
    display: block;
    border-left: 3px solid transparent;
  }
  
  .main-nav[data-open] a:hover,
  .main-nav[data-open] a:active {
    background: rgba(91, 140, 255, 0.15);
    border-left-color: var(--primary-500);
  }
  
  .header-cta {
    position: fixed;
    top: auto;
    right: 0;
    bottom: 0;
    width: 280px;
    max-width: 85vw;
    background: #0a0f1a;
    transform: translateX(100%);
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    z-index: 1000;
    margin-left: 0;
  }
  
  .header-cta[data-open] {
    display: flex;
    flex-direction: column;
    transform: translateX(0);
    border-top: 1px solid var(--border-700);
    padding: 20px 24px;
    gap: 12px;
  }
  
  .header-cta[data-open] .btn {
    width: 100%;
    justify-content: center;
    height: 44px;
  }
  
  /* Menu backdrop overlay */
  .nav-toggle[aria-expanded="true"]::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.6);
    z-index: 999;
    animation: fadeIn 0.3s ease;
  }
  
  @keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
  }
}

.link-muted { color: var(--text-300); text-decoration: none; font-size: 14px; }
.link-muted:hover { color: var(--text-100); }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 36px;
  padding: 0 14px;
  border-radius: 8px;
  border: 1px solid transparent;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  font-size: 14px;
  white-space: nowrap;
}
.btn-primary { background: var(--primary-500); color: #0b1120; border-color: #6b91ff; }
.btn-primary:hover { background: var(--primary-600); }
.btn.btn-ghost { background: transparent; border-color: var(--light-border); color: var(--light-text); }
.btn.btn-ghost:hover { background: rgba(15,23,42,0.05); }
.btn.btn-primary { color: #0b1120; }

@media (min-width: 768px) {
  .btn {
    font-size: 16px;
    padding: 0 16px;
    height: 40px;
  }
}

/* Header-specific ghost button: header is dark even in light theme */
.site-header .btn.btn-ghost { color: var(--text-100); border-color: rgba(255,255,255,0.35); }
.site-header .btn.btn-ghost:hover { background: rgba(255,255,255,0.08); }

.nav-toggle {
  margin-left: auto;
  background: transparent;
  color: var(--text-100);
  border: 0;
  font-size: 24px;
  display: inline-flex;
  cursor: pointer;
  padding: 8px;
  line-height: 1;
  flex-shrink: 0;
  transition: transform 0.2s ease;
}

.nav-toggle[aria-expanded="true"] {
  transform: rotate(90deg);
}

@media (min-width: 768px) {
  .header-inner {
    gap: 16px;
    height: 72px;
  }
  .brand-mark { width: 32px; height: 32px; }
  .brand-name { font-size: 22px; }
}

@media (min-width: 900px) {
  .main-nav { display: flex; }
  .header-cta { display: flex; }
  .nav-toggle { display: none; }
  .mobile-menu-close { display: none !important; }
}

/* Hero */
.hero { padding: 40px 20px 24px 20px; }
.hero-inner { text-align: center; }
.hero h1 { margin: 0 0 10px; font-size: 28px; line-height: 1.2; padding: 0 8px; }
.subtitle { margin: 0 auto 20px; max-width: 720px; color: var(--light-muted); font-size: 16px; padding: 0 8px; }
.hero-actions { display: inline-flex; gap: 12px; flex-wrap: wrap; justify-content: center; }

@media (min-width: 768px) {
  .hero { padding: 56px 20px 24px 20px; }
  .hero h1 { font-size: 42px; padding: 0; }
  .subtitle { font-size: 18px; padding: 0; }
}

/* Features grid */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 16px;
  padding: 32px 16px 56px 16px;
}

@media (min-width: 768px) {
  .features-grid {
    padding: 32px 20px 56px 20px;
  }
}
.feature {
  border: 1px solid var(--light-border);
  border-radius: 12px;
  padding: 16px;
  text-decoration: none;
  color: var(--light-text);
  background: var(--light-card);
  display: grid;
  grid-template-columns: 44px 1fr;
  align-items: center;
  gap: 12px;
}

@media (min-width: 768px) {
  .feature {
    padding: 18px;
    gap: 14px;
  }
}
.features-grid a.feature,
.features-grid a.feature:link,
.features-grid a.feature:visited,
.features-grid a.feature:hover,
.features-grid a.feature:active,
.features-grid a.feature:focus { color: var(--light-text); text-decoration: none; }
.features-grid a.feature h3 { margin: 0 0 6px; font-size: 18px; color: var(--light-text); }
.feature p { margin: 0; color: var(--light-muted); font-size: 14px; }
.feature:hover { border-color: #c7d2fe; box-shadow: 0 4px 14px rgba(17,24,39,0.06); }

.feature-icon {
  width: 44px;
  height: 44px;
  border-radius: 10px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: #1f2937;
  background: #ffffff;
  border: 1.5px solid var(--light-border);
  box-shadow: 0 1px 0 rgba(17,24,39,0.02);
}
.feature-copy { display: flex; flex-direction: column; }

.site-footer { 
  border-top: 1px solid var(--light-border); 
  padding: 20px 16px; 
  background: var(--light-bg);
  flex-shrink: 0;
  margin-top: auto;
}
.footer-inner { text-align: center; color: var(--light-muted); font-size: 14px; }

@media (min-width: 768px) {
  .site-footer { padding: 20px 0; }
}

/* Theme: Dark overrides */
  color: var(--text-100);
  background: radial-gradient(1200px 220px at 50% 0,
              var(--bg-700) 0%, var(--bg-800) 55%, var(--bg-900) 100%) fixed;
}
  border-color: var(--border-700);
  color: var(--text-100);
  background: linear-gradient(180deg, rgba(255,255,255,0.03), rgba(255,255,255,0.01));
}
  color: var(--text-100);
  background: radial-gradient(22px 16px at 50% 30%, rgba(91,140,255,0.35), rgba(255,255,255,0.02));
  border-color: var(--border-700);
}

/* Convert Page Styles */
.tool-header {
  text-align: center;
  margin-bottom: 32px;
  padding: 0 16px;
}

.tool-header h1 {
  font-size: 24px;
  margin: 0 0 12px;
  color: var(--light-text);
  line-height: 1.3;
}

.tool-header .subtitle {
  font-size: 16px;
  color: var(--light-muted);
  margin: 0 auto;
  max-width: 680px;
}

@media (min-width: 768px) {
  .tool-header {
    padding: 0;
  }
  
  .tool-header h1 {
    font-size: 36px;
  }
  
  .tool-header .subtitle {
    font-size: 18px;
  }
}

.card {
  background: var(--light-card);
  border: 1px solid var(--light-border);
  border-radius: 16px;
  padding: 20px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
}

@media (min-width: 768px) {
  .card {
    padding: 32px;
  }
}

.upload-area {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 280px;
  border: 2px dashed var(--light-border);
  border-radius: 12px;
  background: var(--light-bg);
  cursor: pointer;
  transition: all 0.2s ease;
  padding: 30px 16px;
}

@media (min-width: 768px) {
  .upload-area {
    min-height: 320px;
    padding: 40px 20px;
  }
}

.upload-area:hover {
  border-color: var(--primary-500);
  background: rgba(91, 140, 255, 0.03);
}

.upload-icon {
  color: var(--light-muted);
  margin-bottom: 20px;
}

.upload-text {
  font-size: 18px;
  color: var(--light-text);
  margin: 0 0 8px;
  padding-top: 12px;
}

.upload-hint {
  font-size: 14px;
  color: var(--light-muted);
  margin: 0;
  padding-top: 4px;
}

.preview-box {
  background: var(--light-bg);
  border: 1px solid var(--light-border);
  border-radius: 12px;
  padding: 12px;
  height: 100%;
}

@media (min-width: 768px) {
  .preview-box {
    padding: 20px;
  }
}

.preview-title {
  font-size: 18px;
  font-weight: 600;
  margin: 0 0 16px;
  color: var(--light-text);
}

.preview-container {
  position: relative;
  width: 100%;
  min-height: 280px;
  background: #f8fafc;
  border: 1px solid var(--light-border);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.preview-container img {
  max-width: 100%;
  max-height: 280px;
  object-fit: contain;
}

.loading-spinner {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  color: var(--light-muted);
}

.image-info {
  margin-top: 12px;
  padding: 12px;
  background: var(--light-card);
  border: 1px solid var(--light-border);
  border-radius: 8px;
  font-size: 14px;
  color: var(--light-text);
}

.info-label {
  font-weight: 600;
  color: var(--light-muted);
}

.controls-section {
  background: var(--light-bg);
  border: 1px solid var(--light-border);
  border-radius: 12px;
  padding: 16px;
}

@media (min-width: 768px) {
  .controls-section {
    padding: 24px;
  }
}

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

.btn-lg {
  height: 48px;
  padding: 0 24px;
  font-size: 16px;
}

.btn-success {
  background: #10b981;
  color: white;
  border-color: #059669;
}

.btn-success:hover {
  background: #059669;
}

.btn-outline-primary {
  background: transparent;
  color: var(--primary-500);
  border-color: var(--primary-500);
}

.btn-outline-primary:hover {
  background: var(--primary-500);
  color: #0b1120;
}

/* SEO Content Section */
.seo-content {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 16px;
}

.seo-content h2 {
  font-size: 22px;
  margin: 0 0 16px;
  color: var(--light-text);
  line-height: 1.3;
}

.seo-content h3 {
  font-size: 18px;
  margin: 0 0 12px;
  color: var(--light-text);
}

.seo-content p {
  color: var(--light-muted);
  line-height: 1.7;
  margin-bottom: 16px;
}

/* Format cards - fix for dark mode and mobile */
.seo-content div[style*="background:var(--light-card)"] {
  background: var(--light-card) !important;
  border-color: var(--light-border) !important;
}

.seo-content div[style*="background:var(--light-card)"] h3 {
  color: var(--light-text) !important;
}

.seo-content div[style*="background:var(--light-card)"] p {
  color: var(--light-muted) !important;
}

/* Mobile padding for content cards */
@media (max-width: 767px) {
  .seo-content div[style*="padding:20px"],
  .seo-content div[style*="padding: 20px"] {
    padding: 16px !important;
  }
  
  .seo-content div[style*="padding:16px"],
  .seo-content div[style*="padding: 16px"] {
    padding: 14px !important;
  }
}

@media (min-width: 768px) {
  .seo-content {
    padding: 0 20px;
  }
  
  .seo-content h2 {
    font-size: 28px;
  }
  
  .seo-content h3 {
    font-size: 20px;
  }
}

.seo-content ul, .seo-content ol {
  color: var(--light-muted);
  line-height: 1.7;
}

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

/* Accordion */
.accordion-item {
  background: var(--light-card);
  border: 1px solid var(--light-border);
  margin-bottom: 8px;
  border-radius: 8px;
  overflow: hidden;
}

.accordion-button {
  background: var(--light-card);
  color: var(--light-text);
  font-weight: 600;
  padding: 14px 16px;
  width: 100%;
  text-align: left;
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 15px;
}

@media (min-width: 768px) {
  .accordion-button {
    padding: 16px 20px;
    font-size: 16px;
  }
}

.accordion-button:hover {
  background: var(--light-bg);
}

.accordion-button:not(.collapsed) {
  background: var(--light-bg);
  color: var(--primary-500);
}

.accordion-body {
  padding: 12px 16px;
  color: var(--light-muted);
  line-height: 1.6;
  font-size: 14px;
}

@media (min-width: 768px) {
  .accordion-body {
    padding: 16px 20px;
    font-size: 16px;
  }
}

/* Dark Mode Overrides for Convert Page */
  color: var(--text-100);
}

  color: var(--text-300);
}

  background: linear-gradient(180deg, rgba(255,255,255,0.04), rgba(255,255,255,0.02));
  border-color: var(--border-700);
  box-shadow: none;
}

  border-color: var(--border-700);
  background: rgba(255, 255, 255, 0.02);
}

  border-color: var(--primary-500);
  background: rgba(91, 140, 255, 0.08);
}

  color: var(--text-300);
}

  color: var(--text-100);
}

  color: var(--text-300);
}

  background: rgba(255, 255, 255, 0.02);
  border-color: var(--border-700);
}

  color: var(--text-100);
}

  background: rgba(0, 0, 0, 0.2);
  border-color: var(--border-700);
}

  color: var(--text-300);
}

  background: rgba(255, 255, 255, 0.03);
  border-color: var(--border-700);
  color: var(--text-100);
}

  color: var(--text-300);
}

  background: rgba(255, 255, 255, 0.02);
  border-color: var(--border-700);
}

  color: var(--primary-500);
  border-color: var(--primary-500);
}

  background: var(--primary-500);
  color: #0b1120;
}

  color: var(--text-100);
}

  color: var(--text-300);
}

/* Dark mode format cards */
  background: linear-gradient(180deg, rgba(255,255,255,0.04), rgba(255,255,255,0.02)) !important;
  border-color: var(--border-700) !important;
}

  color: var(--text-100) !important;
}

  color: var(--text-300) !important;
}

  background: rgba(255, 255, 255, 0.03);
  border-color: var(--border-700);
}

  background: rgba(255, 255, 255, 0.03);
  color: var(--text-100);
}

  background: rgba(255, 255, 255, 0.05);
}

  background: rgba(255, 255, 255, 0.05);
  color: var(--primary-500);
}

  color: var(--text-300);
}

/* Form controls dark mode */
  background: rgba(255, 255, 255, 0.05);
  border-color: var(--border-700);
  color: var(--text-100);
}

  background: rgba(255, 255, 255, 0.08);
  border-color: var(--primary-500);
  color: var(--text-100);
}

  color: var(--text-100);
}

  color: var(--text-300);
}