/* MasterConverter - Production CSS Design System */
:root {
  --color-primary: #4f46e5;
  --color-primary-hover: #4338ca;
  --color-primary-light: #eef2ff;
  --color-primary-dark: #3730a3;
  --color-text: #0f172a;
  --color-text-secondary: #475569;
  --color-text-muted: #64748b;
  --color-bg: #f8fafc;
  --color-surface: #ffffff;
  --color-border: #e2e8f0;
  --color-border-hover: #cbd5e1;
  --color-success: #10b981;
  --color-success-bg: #ecfdf5;
  --color-error: #ef4444;
  --color-error-bg: #fef2f2;
  --color-warning: #f59e0b;
  --color-warning-bg: #fffbeb;
  
  --font-sans: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -1px rgba(0, 0, 0, 0.04);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -2px rgba(0, 0, 0, 0.03);
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --radius-xl: 18px;
  --max-width: 1200px;
  --transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
  font-family: var(--font-sans);
  background-color: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

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

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

.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
}

/* Header & Navigation */
.site-header {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 50;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-text);
  text-decoration: none;
}

.brand-icon {
  width: 34px;
  height: 34px;
  background: var(--color-primary);
  color: #fff;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 24px;
  list-style: none;
}

.nav-link {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  padding: 6px 10px;
  border-radius: var(--radius-sm);
}

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

.mobile-nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
  color: var(--color-text);
}

/* Hero Section */
.hero {
  padding: 60px 0 40px;
  text-align: center;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  background: var(--color-primary-light);
  color: var(--color-primary);
  border-radius: 9999px;
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 20px;
}

.hero h1 {
  font-size: 2.75rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--color-text);
  line-height: 1.2;
  margin-bottom: 16px;
}

.hero-p {
  font-size: 1.15rem;
  color: var(--color-text-secondary);
  max-width: 680px;
  margin: 0 auto 32px;
}

/* Search Input */
.search-wrapper {
  max-width: 580px;
  margin: 0 auto 40px;
  position: relative;
}

.search-input {
  width: 100%;
  padding: 16px 20px 16px 48px;
  font-size: 1rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  outline: none;
  transition: var(--transition);
}

.search-input:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 4px rgba(79, 70, 229, 0.12);
}

.search-icon {
  position: absolute;
  left: 18px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--color-text-muted);
  pointer-events: none;
}

/* Category Cards */
.categories-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 16px;
  margin-bottom: 60px;
}

.category-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 24px 20px;
  text-align: center;
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
}

.category-card:hover {
  transform: translateY(-3px);
  border-color: var(--color-primary);
  box-shadow: var(--shadow-md);
}

.category-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  background: var(--color-primary-light);
  color: var(--color-primary);
  display: flex;
  align-items: center;
  justify-content: center;
}

.category-name {
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--color-text);
}

.category-desc {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  line-height: 1.4;
}

/* Section Titles */
.section-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin-bottom: 24px;
}

.section-title {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-text);
}

.section-link {
  font-size: 0.9rem;
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 4px;
}

/* Tools Grid */
.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
  margin-bottom: 60px;
}

.tool-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 22px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: var(--transition);
}

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

.tool-header {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 12px;
}

.tool-badge {
  font-size: 0.75rem;
  text-transform: uppercase;
  font-weight: 700;
  padding: 4px 8px;
  background: #f1f5f9;
  color: var(--color-text-secondary);
  border-radius: var(--radius-sm);
}

.tool-title {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--color-text);
}

.tool-desc {
  font-size: 0.88rem;
  color: var(--color-text-secondary);
  line-height: 1.5;
  margin-bottom: 16px;
}

.tool-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 14px;
  border-top: 1px solid var(--color-border);
  font-size: 0.85rem;
}

.format-pill {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--color-primary);
  background: var(--color-primary-light);
  padding: 2px 8px;
  border-radius: 9999px;
}

/* Breadcrumbs */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.88rem;
  color: var(--color-text-muted);
  margin: 24px 0 16px;
}

.breadcrumb-sep {
  color: #cbd5e1;
}

/* Converter Tool Page Interface */
.converter-container {
  max-width: 840px;
  margin: 0 auto 60px;
}

.tool-page-header {
  text-align: center;
  margin-bottom: 32px;
}

.tool-page-header h1 {
  font-size: 2.25rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 12px;
}

.tool-page-header p {
  font-size: 1.1rem;
  color: var(--color-text-secondary);
  max-width: 640px;
  margin: 0 auto;
}

/* Upload Dropzone */
.dropzone-card {
  background: var(--color-surface);
  border: 2px dashed var(--color-border);
  border-radius: var(--radius-xl);
  padding: 48px 24px;
  text-align: center;
  cursor: pointer;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.dropzone-card:hover, .dropzone-card.dragover {
  border-color: var(--color-primary);
  background: #fbfbfe;
}

.dropzone-icon {
  width: 64px;
  height: 64px;
  margin: 0 auto 16px;
  color: var(--color-primary);
  background: var(--color-primary-light);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
}

.dropzone-title {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.dropzone-subtitle {
  font-size: 0.95rem;
  color: var(--color-text-muted);
  margin-bottom: 20px;
}

.file-limits-text {
  font-size: 0.8rem;
  color: var(--color-text-muted);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  transition: var(--transition);
  text-decoration: none;
}

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

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

.btn-secondary {
  background: #f1f5f9;
  color: var(--color-text);
}

.btn-secondary:hover {
  background: #e2e8f0;
}

.btn-success {
  background: var(--color-success);
  color: #fff;
}

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

/* File Selected / Staged State */
.staged-file-card {
  display: none;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 20px;
  margin-top: 20px;
}

.staged-file-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.staged-file-info {
  display: flex;
  align-items: center;
  gap: 16px;
}

.staged-file-icon {
  width: 44px;
  height: 44px;
  background: var(--color-primary-light);
  color: var(--color-primary);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
}

.staged-filename {
  font-weight: 600;
  font-size: 1rem;
  max-width: 320px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.staged-filesize {
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

.btn-remove {
  background: none;
  border: none;
  color: var(--color-error);
  cursor: pointer;
  padding: 8px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
}

.btn-remove:hover {
  background: var(--color-error-bg);
}

/* Options Box */
.options-box {
  background: #f8fafc;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 20px;
  margin: 20px 0;
}

.options-title {
  font-size: 0.95rem;
  font-weight: 700;
  margin-bottom: 14px;
  color: var(--color-text);
  display: flex;
  align-items: center;
  gap: 6px;
}

.form-group {
  margin-bottom: 14px;
}

.form-label {
  display: block;
  font-size: 0.88rem;
  font-weight: 600;
  margin-bottom: 6px;
}

.form-control {
  width: 100%;
  padding: 10px 14px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: #fff;
  font-size: 0.95rem;
}

.form-range {
  width: 100%;
  accent-color: var(--color-primary);
}

/* Progress & Status */
.progress-card {
  display: none;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 28px;
  text-align: center;
  margin-top: 20px;
}

.progress-bar-container {
  height: 8px;
  width: 100%;
  background: #e2e8f0;
  border-radius: 9999px;
  overflow: hidden;
  margin: 16px 0;
}

.progress-bar-fill {
  height: 100%;
  width: 0%;
  background: var(--color-primary);
  transition: width 0.2s ease;
}

.progress-bar-fill.indeterminate {
  width: 40%;
  animation: pulse-indeterminate 1.5s infinite ease-in-out;
}

@keyframes pulse-indeterminate {
  0% { transform: translateX(-100%); }
  100% { transform: translateX(300%); }
}

.progress-status-text {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--color-text-secondary);
}

/* Success Card */
.success-card {
  display: none;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 32px;
  text-align: center;
  margin-top: 20px;
}

.success-icon {
  width: 60px;
  height: 60px;
  background: var(--color-success-bg);
  color: var(--color-success);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 16px;
}

.success-title {
  font-size: 1.35rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.success-meta {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  margin-bottom: 24px;
}

.success-actions {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}

/* Error Alert */
.alert-error {
  display: none;
  background: var(--color-error-bg);
  border: 1px solid #fecaca;
  color: #b91c1c;
  padding: 16px;
  border-radius: var(--radius-md);
  margin-top: 20px;
  font-size: 0.95rem;
  text-align: left;
}

/* Unavailable Notice */
.alert-warning {
  background: var(--color-warning-bg);
  border: 1px solid #fde68a;
  color: #92400e;
  padding: 16px 20px;
  border-radius: var(--radius-md);
  margin-bottom: 24px;
  font-size: 0.95rem;
  display: flex;
  align-items: flex-start;
  gap: 12px;
}

/* Content & FAQ sections */
.content-section {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 36px;
  margin-bottom: 40px;
}

.content-section h2 {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 16px;
  color: var(--color-text);
}

.content-section p {
  color: var(--color-text-secondary);
  line-height: 1.7;
  margin-bottom: 16px;
}

.how-to-steps {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 20px;
  margin: 24px 0 10px;
}

.step-card {
  background: #f8fafc;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 20px;
}

.step-num {
  width: 28px;
  height: 28px;
  background: var(--color-primary);
  color: #fff;
  border-radius: 50%;
  font-weight: 700;
  font-size: 0.85rem;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 12px;
}

.step-text {
  font-size: 0.92rem;
  color: var(--color-text-secondary);
  line-height: 1.5;
}

/* Accordion FAQs */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-top: 20px;
}

.faq-item {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.faq-question {
  width: 100%;
  text-align: left;
  padding: 16px 20px;
  background: #fff;
  border: none;
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-text);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  transition: var(--transition);
}

.faq-question:hover {
  background: #f8fafc;
}

.faq-answer {
  padding: 0 20px 16px;
  font-size: 0.92rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
  background: #fff;
}

/* Footer */
.site-footer {
  margin-top: auto;
  background: #0f172a;
  color: #94a3b8;
  padding: 50px 0 30px;
  font-size: 0.9rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 32px;
  margin-bottom: 40px;
}

.footer-brand {
  font-size: 1.25rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 12px;
}

.footer-desc {
  line-height: 1.6;
  max-width: 320px;
}

.footer-col h4 {
  color: #fff;
  font-size: 0.95rem;
  font-weight: 700;
  margin-bottom: 16px;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-link {
  color: #94a3b8;
  text-decoration: none;
}

.footer-link:hover {
  color: #fff;
}

.footer-bottom {
  padding-top: 24px;
  border-top: 1px solid #1e293b;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
  font-size: 0.85rem;
}

/* Responsive Breakpoints */
@media (max-width: 768px) {
  .hero h1 {
    font-size: 2rem;
  }
  .header-inner {
    height: 60px;
  }
  .nav-links {
    display: none;
  }
  .mobile-nav-toggle {
    display: block;
  }
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 24px;
  }
  .content-section {
    padding: 24px;
  }
  .dropzone-card {
    padding: 32px 16px;
  }
}