/* ==========================================================================
   SEO META PREVIEWER — DESIGN SYSTEM & COMPONENT STYLES
   Features: Glassmorphism, Container Queries, :has() Parent Highlighting,
             Dark Mode Toggle, Pixel-Accurate Google SERP Tokens
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. Design Tokens & Theme Variables
   -------------------------------------------------------------------------- */
:root {
  color-scheme: light;

  /* Google Brand Colors */
  --google-blue: #1a0dab;
  --google-blue-hover: #170bb5;
  --google-text: #202124;
  --google-muted: #4d5156;
  --google-green: #34a853;
  --google-amber: #fbbc04;
  --google-amber-text: #b06000;
  --google-red: #d93025;
  --google-red-bg: rgba(217, 48, 37, 0.06);
  --google-red-border: rgba(217, 48, 37, 0.35);

  /* Light Theme Interface Tokens (Glassmorphic) */
  --bg-app: linear-gradient(135deg, #f5f7fa 0%, #e4e8f0 100%);
  --bg-panel: rgba(255, 255, 255, 0.72);
  --bg-panel-border: rgba(255, 255, 255, 0.6);
  --panel-blur: blur(14px);
  --text-main: #1e293b;
  --text-secondary: #64748b;
  --panel-shadow: 0 10px 30px -5px rgba(0, 0, 0, 0.06), 0 4px 10px -2px rgba(0, 0, 0, 0.04);
  --input-bg: rgba(255, 255, 255, 0.9);
  --input-border: #cbd5e1;
  --input-focus: #3b82f6;
  --track-bg: #e2e8f0;
  --btn-toggle-bg: rgba(241, 245, 249, 0.85);
  --btn-toggle-active-bg: #ffffff;
  --btn-toggle-active-color: #1e293b;
  --btn-toggle-active-shadow: 0 2px 6px rgba(0, 0, 0, 0.1);
}

/* Dark Theme Overrides for App Interface */
body.dark {
  color-scheme: dark;

  --bg-app: linear-gradient(135deg, #090d16 0%, #0f172a 50%, #111827 100%);
  --bg-panel: rgba(15, 23, 42, 0.65);
  --bg-panel-border: rgba(255, 255, 255, 0.12);
  --panel-blur: blur(24px);
  --text-main: #f8fafc;
  --text-secondary: #94a3b8;
  --panel-shadow: 0 20px 48px -10px rgba(0, 0, 0, 0.5), 0 8px 20px -4px rgba(0, 0, 0, 0.35), inset 0 1px 0 0 rgba(255, 255, 255, 0.1);
  --input-bg: rgba(15, 23, 42, 0.75);
  --input-border: #334155;
  --input-focus: #60a5fa;
  --track-bg: #334155;
  --btn-toggle-bg: rgba(15, 23, 42, 0.6);
  --btn-toggle-active-bg: #334155;
  --btn-toggle-active-color: #f8fafc;
  --btn-toggle-active-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
  --google-green: #4ade80;
  --google-amber: #f59e0b;
  --google-amber-text: #fbbf24;
  --google-red-bg: rgba(217, 48, 37, 0.15);
  --google-red-border: rgba(239, 68, 68, 0.5);
}

/* Graceful fallback when backdrop-filter is unsupported */
@supports not ((backdrop-filter: blur(24px)) or (-webkit-backdrop-filter: blur(24px))) {
  :root {
    --bg-panel: rgba(255, 255, 255, 0.96);
  }
  body.dark {
    --bg-panel: rgba(30, 41, 59, 0.96);
  }
}

/* --------------------------------------------------------------------------
   2. Base & Layout
   -------------------------------------------------------------------------- */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg-app);
  background-color: #090d16;
  color: var(--text-main);
  min-height: 100vh;
  line-height: 1.5;
  transition: background 0.3s ease, color 0.3s ease;
  padding: 24px 16px 60px 16px;
  position: relative;
  overflow-x: hidden;
  isolation: isolate;
}

/* ==========================================================================
   REQUIREMENT R2: Animated Mesh Gradient Background
   Flows vibrant gradients behind frosted glass panels
   ========================================================================== */
.mesh-gradient-bg {
  position: fixed;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  z-index: -1;
  pointer-events: none;
  background:
    radial-gradient(circle at 18% 22%, rgba(99, 102, 241, 0.35) 0%, transparent 45%),
    radial-gradient(circle at 82% 18%, rgba(168, 85, 247, 0.3) 0%, transparent 45%),
    radial-gradient(circle at 78% 78%, rgba(59, 130, 246, 0.35) 0%, transparent 45%),
    radial-gradient(circle at 22% 82%, rgba(236, 72, 153, 0.28) 0%, transparent 45%),
    radial-gradient(circle at 50% 50%, rgba(14, 165, 233, 0.22) 0%, transparent 50%);
  filter: blur(60px);
  animation: meshGradientAnimation 18s ease-in-out infinite alternate;
  will-change: transform;
}

@keyframes meshGradientAnimation {
  0% {
    transform: translate3d(0, 0, 0) rotate(0deg) scale(1);
  }
  33% {
    transform: translate3d(-3%, 4%, 0) rotate(60deg) scale(1.08);
  }
  66% {
    transform: translate3d(4%, -3%, 0) rotate(120deg) scale(0.95);
  }
  100% {
    transform: translate3d(-2%, 2%, 0) rotate(180deg) scale(1.04);
  }
}

@media (prefers-reduced-motion: reduce) {
  .mesh-gradient-bg {
    animation: none !important;
  }
}

.app-wrapper {
  max-width: 1320px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

/* Header */
.app-header {
  border-radius: 16px;
  background: var(--bg-panel);
  border: 1px solid var(--bg-panel-border);
  -webkit-backdrop-filter: var(--panel-blur);
  backdrop-filter: var(--panel-blur);
  box-shadow: var(--panel-shadow);
  padding: 16px 24px;
  transition: all 0.3s ease;
}

.header-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
}

.brand-group {
  display: flex;
  align-items: center;
  gap: 14px;
}

.brand-logo {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: linear-gradient(135deg, #3b82f6 0%, #2563eb 100%);
  color: #ffffff;
  box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
}

.brand-title {
  font-size: 20px;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text-main);
}

.brand-subtitle {
  font-size: 13px;
  color: var(--text-secondary);
}


/* Main Grid Layout */
.app-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  align-items: start;
}

@media (max-width: 980px) {
  .app-layout {
    grid-template-columns: 1fr;
  }
}

/* --------------------------------------------------------------------------
   3. Glassmorphism Configuration Panels
   -------------------------------------------------------------------------- */
.controls-panel,
.preview-panel {
  background: var(--bg-panel);
  border: 1px solid var(--bg-panel-border);
  border-radius: 20px;
  -webkit-backdrop-filter: var(--panel-blur);
  backdrop-filter: var(--panel-blur);
  box-shadow: var(--panel-shadow);
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 20px;
  transition: all 0.3s ease;
}

.panel-heading {
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--text-main);
}

/* Form Groups & Parent Validation Highlighting via :has() */
.snippet-form {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 16px;
  border-radius: 14px;
  background: rgba(255, 255, 255, 0.4);
  border: 1px solid transparent;
  transition: border-color 0.25s ease, background-color 0.25s ease, box-shadow 0.25s ease;
}

body.dark .form-group {
  background: rgba(15, 23, 42, 0.4);
}

/* ==========================================================================
   REQUIREMENT R3: Parent Validation Highlighting via CSS :has()
   Highlights the entire input group with red border, background tint & ring
   when the child title exceeds 600px (causing .error / .truncated classes)
   ========================================================================== */
.form-group:has(#input-title.error),
.form-group:has(#input-description.error),
.form-group:has(#title-counter.error),
.form-group:has(#title-counter.truncated),
.form-group:has(#desc-counter.error),
.form-group:has(#desc-counter.truncated),
.form-group:has(#title-progress.error),
.form-group:has(#title-progress.truncated),
.form-group:has(#desc-progress.error),
.form-group:has(#desc-progress.truncated),
.form-group:has(input.error),
.form-group:has(textarea.error),
.form-group:has(.counter-badge.error),
.form-group:has(.counter-badge.truncated),
.form-group:has(.progress-bar.error),
.form-group:has(.progress-bar.truncated),
.form-group:has(.error),
.form-group:has(.truncated),
.form-group:has([aria-invalid="true"]) {
  border-color: var(--google-red, #d93025);
  background-color: var(--google-red-bg);
  box-shadow: 0 0 0 3px rgba(217, 48, 37, 0.16);
}

body.dark .form-group:has(#input-title.error),
body.dark .form-group:has(#input-description.error),
body.dark .form-group:has(#title-counter.error),
body.dark .form-group:has(#title-counter.truncated),
body.dark .form-group:has(#desc-counter.error),
body.dark .form-group:has(#desc-counter.truncated),
body.dark .form-group:has(#title-progress.error),
body.dark .form-group:has(#title-progress.truncated),
body.dark .form-group:has(#desc-progress.error),
body.dark .form-group:has(#desc-progress.truncated),
body.dark .form-group:has(input.error),
body.dark .form-group:has(textarea.error),
body.dark .form-group:has(.counter-badge.error),
body.dark .form-group:has(.counter-badge.truncated),
body.dark .form-group:has(.progress-bar.error),
body.dark .form-group:has(.progress-bar.truncated),
body.dark .form-group:has(.error),
body.dark .form-group:has(.truncated),
body.dark .form-group:has([aria-invalid="true"]) {
  border-color: #ef4444;
  background-color: rgba(239, 68, 68, 0.12);
  box-shadow: 0 0 0 3px rgba(239, 68, 68, 0.25);
}

.label-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
  row-gap: 6px;
}

label {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-main);
}

/* ==========================================================================
   REQUIREMENT R3: Copy to Clipboard Buttons
   ========================================================================== */
.field-controls {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.btn-copy {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 3px 8px;
  min-height: 24px;
  font-size: 11px;
  font-weight: 600;
  font-family: inherit;
  border-radius: 6px;
  border: 1px solid var(--input-border);
  background: var(--btn-toggle-bg);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.2s ease;
  line-height: 1.2;
  user-select: none;
  -webkit-user-select: none;
  touch-action: manipulation;
}

.btn-copy:hover {
  background: var(--input-bg);
  color: var(--text-main);
  border-color: var(--input-focus);
  transform: translateY(-1px);
}

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

.btn-copy:focus-visible {
  outline: 2px solid var(--input-focus);
  outline-offset: 2px;
}

.btn-copy.copied {
  background: rgba(34, 197, 94, 0.18);
  color: #4ade80;
  border-color: rgba(74, 222, 128, 0.4);
}

.btn-copy.copy-error {
  background: rgba(239, 68, 68, 0.18);
  color: #ef4444;
  border-color: rgba(239, 68, 68, 0.4);
}

.btn-copy .copy-icon {
  flex-shrink: 0;
  width: 12px;
  height: 12px;
}

/* Counters & Badges */
.counter-badge {
  font-size: 12px;
  font-weight: 600;
  padding: 3px 8px;
  border-radius: 6px;
  background: var(--track-bg);
  color: var(--text-secondary);
  transition: all 0.2s ease;
  white-space: nowrap;
}

.counter-badge.safe {
  color: var(--google-green);
}

.counter-badge.warning {
  color: var(--google-amber-text);
  background: rgba(251, 188, 4, 0.15);
}

/* Error / Truncated State: Strict Google Red (#d93025) */
.counter-badge.error,
.counter-badge.truncated,
#title-counter.error,
#title-counter.truncated,
#desc-counter.error,
#desc-counter.truncated {
  color: var(--google-red, #d93025) !important;
  background-color: var(--google-red-bg);
  border: 1px solid var(--google-red-border);
  font-weight: 700;
}

/* Inputs */
.input-wrapper input,
.input-wrapper textarea {
  width: 100%;
  padding: 10px 14px;
  border-radius: 10px;
  border: 1px solid var(--input-border);
  background: var(--input-bg);
  color: var(--text-main);
  font-size: 14px;
  font-family: inherit;
  outline: none;
  transition: border-color 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}

.input-wrapper input::placeholder,
.input-wrapper textarea::placeholder {
  color: var(--text-secondary);
  opacity: 0.85;
}

.input-wrapper input:focus,
.input-wrapper textarea:focus {
  border-color: var(--input-focus);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.18);
}

.input-wrapper input.error,
.input-wrapper textarea.error {
  border-color: var(--google-red, #d93025);
  box-shadow: 0 0 0 3px rgba(217, 48, 37, 0.16);
}

.input-wrapper input.error:focus,
.input-wrapper textarea.error:focus {
  border-color: var(--google-red, #d93025);
  box-shadow: 0 0 0 3px rgba(217, 48, 37, 0.28);
}

body.dark .input-wrapper input.error,
body.dark .input-wrapper textarea.error {
  border-color: #ef4444;
  box-shadow: 0 0 0 3px rgba(239, 68, 68, 0.2);
}

body.dark .input-wrapper input.error:focus,
body.dark .input-wrapper textarea.error:focus {
  border-color: #ef4444;
  box-shadow: 0 0 0 3px rgba(239, 68, 68, 0.35);
}

.field-hint {
  font-size: 11px;
  color: var(--text-secondary);
}

/* Progress Bars */
.progress-track {
  width: 100%;
  height: 6px;
  background: var(--track-bg);
  border-radius: 999px;
  overflow: hidden;
}

.progress-bar {
  height: 100%;
  border-radius: 999px;
  background: var(--google-green);
  transition: width 0.15s ease, background-color 0.2s ease;
}

.progress-bar.warning {
  background: var(--google-amber);
}

.progress-bar.error,
.progress-bar.truncated {
  background: var(--google-red, #d93025) !important;
}

/* --------------------------------------------------------------------------
   4. Preview Panel Header & Device Toggles
   -------------------------------------------------------------------------- */
.preview-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
}

.device-toggle {
  display: inline-flex;
  padding: 4px;
  background: var(--btn-toggle-bg);
  border: 1px solid var(--input-border);
  border-radius: 12px;
  gap: 4px;
}

.toggle-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  border-radius: 8px;
  border: none;
  background: transparent;
  color: var(--text-secondary);
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
}

.toggle-btn.active {
  background: var(--btn-toggle-active-bg);
  color: var(--btn-toggle-active-color);
  box-shadow: var(--btn-toggle-active-shadow);
}

/* --------------------------------------------------------------------------
   5. Google SERP Card Base Styling
   ==========================================================================
   CRITICAL REQUIREMENT R1: The Google SERP preview card MUST REMAIN LIGHT
   in both light and dark themes to reflect an authentic Google Search!
   -------------------------------------------------------------------------- */
.serp-card,
#serp-preview,
body.dark .serp-card,
body.dark #serp-preview {
  color-scheme: light !important;
  background-color: #ffffff !important;
  color: #202124 !important;
  border-radius: 8px;
  padding: 16px 20px;
  font-family: Arial, sans-serif;
  text-align: left;
  box-shadow: 0 1px 6px rgba(32, 33, 36, 0.12), 0 1px 1px rgba(0, 0, 0, 0.04);
  transition: all 0.25s ease;
}

/* Desktop Mode SERP Card Base */
.serp-card.mode-desktop,
#serp-preview.mode-desktop {
  width: 100%;
  max-width: 652px;
  border: 1px solid #dfe1e5;
  border-radius: 8px;
}

/* Mobile Mode SERP Card (Strict 375px Emulated Viewport) */
.serp-card.mode-mobile,
#serp-preview.mode-mobile {
  width: min(375px, 100%);
  max-width: min(375px, 100%);
  margin: 0 auto;
  border: 1px solid #dadce0;
  border-radius: 16px;
  box-shadow: 0 1px 6px rgba(32, 33, 36, 0.16);
  padding: 14px 16px;
}

/* SERP Header Row: Favicon + Site Name + Breadcrumb */
.serp-header {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 8px;
}

.serp-favicon {
  width: 26px;
  height: 26px;
  border-radius: 50%;
  background: #f1f3f4;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.serp-site-info {
  display: flex;
  flex-direction: column;
  line-height: 1.3;
  overflow: hidden;
}

.serp-site-name,
#preview-site-name,
body.dark #preview-site-name {
  font-size: 14px !important;
  font-weight: 500 !important;
  color: #202124 !important;
}

.serp-breadcrumb,
#preview-breadcrumb,
body.dark #preview-breadcrumb {
  font-size: 12px !important;
  color: #4d5156 !important;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* SERP Title Heading & Anchor */
.serp-title {
  margin: 0 0 6px 0;
  font-weight: 400;
}

.serp-title a,
#preview-title,
body.dark #preview-title {
  font-family: 'Google Sans', Roboto, Arial, sans-serif !important;
  font-size: 20px !important;
  line-height: 26px !important;
  color: #1a0dab !important;
  text-decoration: none;
  cursor: pointer;
  display: inline-block;
  max-width: 600px;
  word-break: break-word;
}

.serp-title a:hover {
  text-decoration: underline !important;
}

.serp-title a:visited,
#preview-title:visited,
body.dark #preview-title:visited {
  color: #1a0dab !important;
}

/* Mode-specific Title Wrapping */
.serp-card.mode-desktop .serp-title a {
  white-space: normal;
}

.serp-card.mode-mobile .serp-title a {
  max-width: 100%;
  white-space: normal;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* SERP Description Snippet */
.serp-snippet,
#preview-description,
body.dark #preview-description {
  font-size: 14px !important;
  line-height: 20px !important;
  color: #4d5156 !important;
  margin: 0;
  max-width: 600px;
  word-break: break-word;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.serp-card.mode-mobile .serp-snippet {
  -webkit-line-clamp: 3;
}

/* --------------------------------------------------------------------------
   6. Container Queries Implementation for SERP Preview
   ==========================================================================
   REQUIREMENT R2: Replace old preview @media queries with @container queries
   The preview container responds to container width rather than viewport.
   Placed AFTER base SERP styles so container rules override base rules cleanly.
   -------------------------------------------------------------------------- */
.serp-viewport {
  container-type: inline-size;
  container-name: serp-viewport;
  display: flex;
  justify-content: flex-start;
  width: 100%;
  overflow-x: auto;
  padding: 8px 0;
}

/* Container Queries for Responsive Layout of the Preview Card */
@container serp-viewport (max-width: 680px) {
  .serp-card.mode-desktop,
  #serp-preview.mode-desktop {
    max-width: 100%;
  }
}

@container serp-viewport (max-width: 480px) {
  .serp-card.mode-desktop,
  #serp-preview.mode-desktop {
    max-width: 100%;
    padding: 12px 14px;
  }
  .serp-card .serp-title a,
  .serp-card #preview-title,
  #serp-preview #preview-title,
  body.dark .serp-card #preview-title,
  body.dark #serp-preview #preview-title {
    font-size: 18px !important;
    line-height: 24px !important;
  }
}

@container serp-viewport (max-width: 380px) {
  .serp-card.mode-mobile,
  #serp-preview.mode-mobile {
    width: 100%;
    max-width: 100%;
    padding: 12px 14px;
  }
}

@container serp-viewport (min-width: 680px) {
  .serp-card.mode-desktop,
  #serp-preview.mode-desktop {
    max-width: 652px;
  }
}

/* Footer */
.app-footer {
  position: absolute;
  bottom: 16px;
  left: 0;
  right: 0;
  text-align: center;
  font-size: 12px;
  color: var(--text-secondary);
  padding: 8px 0;
}