/* ═══════════════════════════════════════════════════════════════════════════
   Code Review Assistant — Design System & Styles
   High-contrast Light/Dark themes with micro-animations
   ═══════════════════════════════════════════════════════════════════════════ */

/* ── CSS Custom Properties ─────────────────────────────────────────────── */
:root,
[data-theme="dark"] {
  /* High Contrast Dark Mode Background */
  --bg-gradient-start: #000000;
  --bg-gradient-mid: #0a0a0a;
  --bg-gradient-end: #111111;

  /* Surfaces (glassmorphism) */
  --surface: rgba(255, 255, 255, 0.03);
  --surface-hover: rgba(255, 255, 255, 0.08);
  --surface-border: rgba(255, 255, 255, 0.12);
  --surface-border-hover: rgba(255, 255, 255, 0.2);

  /* Text */
  --text-primary: #ededed;
  --text-secondary: #a1a1aa;
  --text-muted: #71717a;

  /* Accent – electric purple to bright blue */
  --accent-start: #a855f7;
  --accent-end: #3b82f6;
  --accent-gradient: linear-gradient(
    135deg,
    var(--accent-start),
    var(--accent-end)
  );
  --accent-glow: rgba(168, 85, 247, 0.35);

  /* Semantic colors */
  --positive: #10b981;
  --positive-bg: rgba(16, 185, 129, 0.1);
  --positive-border: rgba(16, 185, 129, 0.25);

  --error: #ef4444;
  --error-bg: rgba(239, 68, 68, 0.1);
  --error-border: rgba(239, 68, 68, 0.25);

  --warning: #f59e0b;

  /* Grain/Effect Colors */
  --grain-color-1: rgba(168, 85, 247, 0.1);
  --grain-color-2: rgba(59, 130, 246, 0.08);

  /* Component-specific overrides */
  --select-bg: #111111;
  --sidebar-bg: rgba(10, 10, 10, 0.95);
  --toast-bg: rgba(20, 20, 20, 0.95);
  --code-bg: rgba(0, 0, 0, 0.5);

  /* Spacing */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;

  /* Radii */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 20px;

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
  --transition-slow: 400ms ease;

  /* Typography */
  --font-ui: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-code: "JetBrains Mono", "Fira Code", "Cascadia Code", monospace;

  /* Z-index layers */
  --z-sidebar: 100;
  --z-overlay: 90;
  --z-toast: 200;
}

[data-theme="light"] {
  /* High Contrast Light Mode Background */
  --bg-gradient-start: #f8fafc;
  --bg-gradient-mid: #f1f5f9;
  --bg-gradient-end: #e2e8f0;

  /* Surfaces (solid vs glass) */
  --surface: #ffffff;
  --surface-hover: #f1f5f9;
  --surface-border: #cbd5e1;
  --surface-border-hover: #94a3b8;

  /* Text */
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #64748b;

  /* Accent – deeper purple to blue to maintain contrast */
  --accent-start: #7e22ce;
  --accent-end: #2563eb;
  --accent-gradient: linear-gradient(
    135deg,
    var(--accent-start),
    var(--accent-end)
  );
  --accent-glow: rgba(126, 34, 206, 0.25);

  /* Semantic colors */
  --positive: #059669;
  --positive-bg: rgba(5, 150, 105, 0.1);
  --positive-border: rgba(5, 150, 105, 0.3);

  --error: #dc2626;
  --error-bg: rgba(220, 38, 38, 0.1);
  --error-border: rgba(220, 38, 38, 0.3);

  --warning: #d97706;

  /* Grain/Effect Colors */
  --grain-color-1: rgba(126, 34, 206, 0.04);
  --grain-color-2: rgba(37, 99, 235, 0.03);

  /* Component-specific overrides */
  --select-bg: #ffffff;
  --sidebar-bg: rgba(255, 255, 255, 0.95);
  --toast-bg: #ffffff;
  --code-bg: #f8fafc;
}

/* Smooth transition when swapping themes */
html.theme-transition,
html.theme-transition *,
html.theme-transition *::before,
html.theme-transition *::after {
  transition: all 400ms ease !important;
  transition-delay: 0 !important;
}

/* ── Reset & Base ──────────────────────────────────────────────────────── */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-ui);
  color: var(--text-primary);
  background: var(--bg-gradient-start);
  background-image: linear-gradient(
    160deg,
    var(--bg-gradient-start) 0%,
    var(--bg-gradient-mid) 40%,
    var(--bg-gradient-end) 100%
  );
  min-height: 100vh;
  line-height: 1.6;
  overflow-x: hidden;
}

/* Subtle animated background grain */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  background:
    radial-gradient(
      ellipse 600px 400px at 20% 30%,
      var(--grain-color-1) 0%,
      transparent 70%
    ),
    radial-gradient(
      ellipse 500px 350px at 80% 70%,
      var(--grain-color-2) 0%,
      transparent 70%
    );
  pointer-events: none;
  z-index: 0;
}

/* ── Scrollbar ─────────────────────────────────────────────────────────── */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}
::-webkit-scrollbar-track {
  background: transparent;
}
::-webkit-scrollbar-thumb {
  background: var(--surface-border-hover);
  border-radius: 3px;
}
::-webkit-scrollbar-thumb:hover {
  background: var(--text-muted);
}

/* ── Header ────────────────────────────────────────────────────────────── */
.header {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-md) var(--space-xl);
  background: var(--sidebar-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--surface-border);
  box-shadow:
    0 4px 6px -1px rgba(0, 0, 0, 0.05),
    0 2px 4px -1px rgba(0, 0, 0, 0.03);
}

.header-left {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.header-icon {
  font-size: 1.4rem;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: pulse-glow 3s ease-in-out infinite;
}

.header-title-container {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.header-title {
  font-size: 1.1rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.header-subtitle {
  font-size: 0.8rem;
  font-weight: 400;
  color: var(--text-secondary);
}

.header-right {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

/* ── Icon Button ───────────────────────────────────────────────────────── */
.btn-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  border: 1px solid var(--surface-border);
  border-radius: var(--radius-sm);
  background: var(--surface);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.btn-icon:hover {
  background: var(--surface-hover);
  border-color: var(--surface-border-hover);
  color: var(--text-primary);
  transform: translateY(-1px);
}

.theme-toggle-btn.light-mode-active .icon-sun {
  display: none;
}
.theme-toggle-btn.light-mode-active .icon-moon {
  display: block !important;
}

/* ── Main Layout ───────────────────────────────────────────────────────── */
.main {
  position: relative;
  z-index: 1;
  max-width: 820px;
  margin: 0 auto;
  padding: var(--space-xl) var(--space-lg);
}

/* ── Editor Section ────────────────────────────────────────────────────── */
.editor-section {
  background: var(--surface);
  backdrop-filter: blur(24px);
  -webkit-backdrop-filter: blur(24px);
  border: 1px solid var(--surface-border);
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: 0 10px 30px -5px rgba(0, 0, 0, 0.1);
  transition:
    border-color var(--transition-base),
    box-shadow var(--transition-base);
}

.editor-section:focus-within {
  border-color: var(--accent-start);
  box-shadow:
    0 0 0 1px var(--accent-glow),
    0 10px 30px -5px rgba(0, 0, 0, 0.1);
}

.editor-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-md) var(--space-lg);
  border-bottom: 1px solid var(--surface-border);
}

.editor-controls {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.language-select {
  font-family: var(--font-ui);
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-primary);
  background: transparent;
  border: 1px solid var(--surface-border);
  border-radius: var(--radius-sm);
  padding: 6px 12px;
  cursor: pointer;
  transition: all var(--transition-fast);
  appearance: none;
  -webkit-appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%238585a8' stroke-width='2'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 8px center;
  padding-right: 28px;
}

[data-theme="light"] .language-select {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%23475569' stroke-width='2'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
}

.language-select:hover {
  border-color: var(--surface-border-hover);
}

.language-select:focus {
  outline: none;
  border-color: var(--accent-start);
}

.language-select option {
  background: var(--select-bg);
  color: var(--text-primary);
}

.line-count {
  font-size: 0.75rem;
  color: var(--text-muted);
  font-weight: 500;
  font-variant-numeric: tabular-nums;
}

/* CodeMirror container */
.editor-container {
  min-height: 240px;
  max-height: 450px;
  overflow: auto;
}

/* Editor loading skeleton — visible until CodeMirror mounts */
.editor-placeholder {
  padding: var(--space-md) var(--space-lg);
  display: flex;
  flex-direction: column;
  gap: 12px;
  min-height: 240px;
  justify-content: center;
}

.editor-placeholder-line {
  height: 13px;
  border-radius: 6px;
  background: linear-gradient(
    90deg,
    var(--surface-hover) 25%,
    var(--surface-border) 50%,
    var(--surface-hover) 75%
  );
  background-size: 200% 100%;
  animation: shimmer 1.5s ease-in-out infinite;
}

/* CodeMirror theme overrides */
.editor-container .cm-editor {
  background: transparent !important;
  font-family: var(--font-code) !important;
  font-size: 0.875rem !important;
}

.editor-container .cm-editor.cm-focused {
  outline: none !important;
}

.editor-container .cm-gutters {
  background: transparent !important;
  border-right: 1px solid var(--surface-border) !important;
  color: var(--text-muted) !important;
}

.editor-container .cm-activeLineGutter,
.editor-container .cm-activeLine {
  background: var(--surface-hover) !important;
}

.editor-container .cm-scroller {
  font-family: var(--font-code) !important;
  line-height: 1.65 !important;
}

.editor-container .cm-cursor {
  border-left-color: var(--accent-start) !important;
  border-left-width: 2px !important;
}

.editor-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-md) var(--space-lg);
  border-top: 1px solid var(--surface-border);
}

.editor-hint {
  font-size: 0.75rem;
  color: var(--text-muted);
  font-weight: 500;
}

/* ── Clear Editor Button ───────────────────────────────────────────────── */
.btn-clear-editor {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 5px 12px;
  font-family: var(--font-ui);
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-muted);
  background: transparent;
  border: 1px solid var(--surface-border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.btn-clear-editor:hover:not(:disabled) {
  color: var(--error);
  border-color: var(--error-border);
  background: var(--error-bg);
}

.btn-clear-editor:disabled {
  opacity: 0.35;
  cursor: not-allowed;
}

/* ── Review Button ─────────────────────────────────────────────────────── */
.btn-review {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: 10px 22px;
  font-family: var(--font-ui);
  font-size: 0.85rem;
  font-weight: 600;
  color: #fff;
  background: var(--accent-gradient);
  border: 2px solid transparent;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
}

.btn-review::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(255, 255, 255, 0.2), transparent);
  opacity: 0;
  transition: opacity var(--transition-fast);
}

.btn-review:hover:not(:disabled)::before {
  opacity: 1;
}

.btn-review:hover:not(:disabled) {
  box-shadow:
    0 4px 20px var(--accent-glow),
    0 0 40px rgba(139, 92, 246, 0.15);
  transform: translateY(-2px);
}

.btn-review:active:not(:disabled) {
  transform: translateY(0);
}

.btn-review:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  filter: grayscale(0.5);
  box-shadow: none;
}

.btn-review.loading {
  pointer-events: none;
}

.btn-review.loading svg {
  display: none;
}

.btn-spinner {
  display: none;
  width: 16px;
  height: 16px;
  border: 2px solid rgba(255, 255, 255, 0.35);
  border-top-color: #fff;
  border-radius: 50%;
  flex-shrink: 0;
}

.btn-review.loading .btn-spinner {
  display: block;
  animation: btn-spin 0.7s linear infinite;
}

@keyframes btn-spin {
  to {
    transform: rotate(360deg);
  }
}

/* New Review (reset) mode — ghost/outline style */
.btn-review.reset-mode {
  background: transparent;
  background-image: none;
  color: var(--accent-start);
  border: 2px solid var(--accent-start);
  box-shadow: none;
}

.btn-review.reset-mode::before {
  display: none;
}

.btn-review.reset-mode:hover:not(:disabled) {
  background: var(--accent-start);
  background-image: none;
  color: #fff;
  box-shadow: 0 4px 20px var(--accent-glow);
  transform: translateY(-2px);
}

.btn-review.reset-mode svg {
  transition: transform var(--transition-base);
}

.btn-review.reset-mode:hover:not(:disabled) svg {
  transform: rotate(-45deg);
}

/* ── Results Section ───────────────────────────────────────────────────── */
.results-section {
  margin-top: var(--space-xl);
}

.results-section.hidden {
  display: none;
}

.results-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-lg);
}

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

.btn-copy {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 7px 14px;
  font-family: var(--font-ui);
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--text-secondary);
  background: var(--surface);
  border: 1px solid var(--surface-border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.btn-copy:hover {
  color: var(--text-primary);
  background: var(--surface-hover);
  border-color: var(--surface-border-hover);
  transform: translateY(-1px);
}

.btn-copy.copied {
  color: var(--positive);
  border-color: var(--positive-border);
  background: var(--positive-bg);
}

/* ── Review Cards ──────────────────────────────────────────────────────── */
.results-cards {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.review-card {
  background: var(--surface);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--surface-border);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  opacity: 0;
  transform: translateY(16px);
  animation: card-enter 0.5s cubic-bezier(0.16, 1, 0.3, 1) forwards;
  box-shadow:
    0 4px 6px -1px rgba(0, 0, 0, 0.02),
    0 2px 4px -1px rgba(0, 0, 0, 0.02);
  transition:
    border-color var(--transition-fast),
    transform var(--transition-fast);
}

.review-card:hover {
  border-color: var(--surface-border-hover);
  transform: translateY(-2px);
}

.review-card:nth-child(1) {
  animation-delay: 0.05s;
}
.review-card:nth-child(2) {
  animation-delay: 0.15s;
}
.review-card:nth-child(3) {
  animation-delay: 0.25s;
}
.review-card:nth-child(4) {
  animation-delay: 0.35s;
}

/* Positive card */
.review-card.positive {
  border-color: var(--positive-border);
  background: var(--positive-bg);
}

.review-card.positive .card-icon {
  color: var(--positive);
}

/* Improvement card */
.review-card.improvement {
  border-left: 4px solid;
  border-image: var(--accent-gradient) 1;
}

.card-header {
  display: flex;
  align-items: flex-start;
  gap: var(--space-sm);
  margin-bottom: var(--space-sm);
}

.card-icon {
  font-size: 1.1rem;
  flex-shrink: 0;
  margin-top: 1px;
}

.card-label {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
  margin-bottom: 4px;
}

.card-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-primary);
}

.card-description {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-top: var(--space-xs);
  padding-left: 28px;
}

/* Before / After code blocks */
.code-comparison {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-md);
  margin-top: var(--space-md);
  padding-left: 28px;
}

.code-block {
  border-radius: var(--radius-sm);
  overflow: hidden;
  border: 1px solid var(--surface-border);
}

.code-block-label {
  font-size: 0.65rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 8px 12px;
  display: flex;
  align-items: center;
  gap: 6px;
  background: var(--surface-hover);
  border-bottom: 1px solid var(--surface-border);
}

.code-block.before .code-block-label {
  background: var(--error-bg);
  color: var(--error);
  border-bottom-color: var(--error-border);
}

.code-block.after .code-block-label {
  background: var(--positive-bg);
  color: var(--positive);
  border-bottom-color: var(--positive-border);
}

.code-block pre {
  margin: 0;
  padding: var(--space-sm) var(--space-md);
  background: var(--code-bg) !important;
  font-size: 0.825rem;
  line-height: 1.6;
  overflow-x: auto;
  font-family: var(--font-code);
}

.code-block pre code {
  font-family: var(--font-code);
  font-size: 0.825rem;
  background: transparent !important;
}

/* ── Loading Skeleton ──────────────────────────────────────────────────── */
.loading-section {
  margin-top: var(--space-xl);
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.loading-section.hidden {
  display: none;
}

.loading-card {
  background: var(--surface);
  border: 1px solid var(--surface-border);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  opacity: 0;
  animation: card-enter 0.4s ease forwards;
}

.loading-card:nth-child(1) {
  animation-delay: 0s;
}
.loading-card:nth-child(2) {
  animation-delay: 0.08s;
}
.loading-card:nth-child(3) {
  animation-delay: 0.16s;
}
.loading-card:nth-child(4) {
  animation-delay: 0.24s;
}

.skeleton-line {
  height: 12px;
  border-radius: 6px;
  background: linear-gradient(
    90deg,
    var(--surface-hover) 25%,
    var(--surface-border) 50%,
    var(--surface-hover) 75%
  );
  background-size: 200% 100%;
  animation: shimmer 1.5s ease-in-out infinite;
  margin-bottom: var(--space-sm);
}

.skeleton-line.short {
  width: 35%;
}
.skeleton-line.medium {
  width: 70%;
}

.skeleton-code {
  height: 60px;
  border-radius: var(--radius-sm);
  margin-top: var(--space-sm);
  background: linear-gradient(
    90deg,
    var(--surface-hover) 25%,
    var(--surface-border) 50%,
    var(--surface-hover) 75%
  );
  background-size: 200% 100%;
  animation: shimmer 1.5s ease-in-out infinite;
}

/* ── Error Message ─────────────────────────────────────────────────────── */
.error-message {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  margin-top: var(--space-lg);
  padding: var(--space-md) var(--space-lg);
  background: var(--error-bg);
  border: 1px solid var(--error-border);
  border-radius: var(--radius-md);
  color: var(--error);
  font-size: 0.9rem;
  font-weight: 500;
  animation: card-enter 0.3s ease forwards;
}

.error-message.hidden {
  display: none;
}

/* ── History Sidebar ───────────────────────────────────────────────────── */
.sidebar-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.4);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  z-index: var(--z-overlay);
  opacity: 0;
  transition: opacity var(--transition-base);
  pointer-events: none;
}

.sidebar-overlay.visible {
  opacity: 1;
  pointer-events: auto;
}

.sidebar-overlay.hidden {
  display: none;
}

.sidebar {
  position: fixed;
  top: 0;
  right: 0;
  width: 380px;
  max-width: 90vw;
  height: 100vh;
  background: var(--sidebar-bg);
  backdrop-filter: blur(30px);
  -webkit-backdrop-filter: blur(30px);
  border-left: 1px solid var(--surface-border);
  box-shadow: -10px 0 30px rgba(0, 0, 0, 0.1);
  z-index: var(--z-sidebar);
  display: flex;
  flex-direction: column;
  transform: translateX(100%);
  transition: transform var(--transition-slow) cubic-bezier(0.16, 1, 0.3, 1);
}

.sidebar.visible {
  transform: translateX(0);
}

.sidebar.hidden {
  display: none;
}

.sidebar-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-lg);
  border-bottom: 1px solid var(--surface-border);
  flex-shrink: 0;
}

.sidebar-title {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-primary);
}

.sidebar-content {
  flex: 1;
  overflow-y: auto;
  padding: var(--space-md);
}

.sidebar-footer {
  padding: var(--space-md) var(--space-lg);
  border-top: 1px solid var(--surface-border);
  flex-shrink: 0;
}

/* History items */
.history-item {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  padding: var(--space-md);
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  transition: all var(--transition-fast);
  margin-bottom: var(--space-sm);
  background: var(--surface);
}

.history-item:hover {
  background: var(--surface-hover);
  border-color: var(--surface-border-hover);
  transform: translateX(-2px);
}

.history-item-info {
  flex: 1;
  min-width: 0;
}

.history-item-lang {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--accent-start);
  margin-bottom: 4px;
}

.history-item-preview {
  font-size: 0.85rem;
  color: var(--text-secondary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  font-family: var(--font-code);
}

.history-item-time {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: 6px;
  font-weight: 500;
}

.history-delete {
  flex-shrink: 0;
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: none;
  background: transparent;
  color: var(--text-muted);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
  opacity: 0;
}

.history-item:hover .history-delete {
  opacity: 1;
}

.history-delete:hover {
  color: var(--error);
  background: var(--error-bg);
}

.history-empty {
  text-align: center;
  padding: var(--space-2xl) var(--space-lg);
  color: var(--text-muted);
  font-size: 0.95rem;
  font-weight: 500;
}

.btn-clear {
  width: 100%;
  padding: 12px;
  font-family: var(--font-ui);
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
  background: transparent;
  border: 1px solid var(--surface-border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
}

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

/* ── Toast Notifications ───────────────────────────────────────────────── */
.toast-container {
  position: fixed;
  top: var(--space-lg);
  right: var(--space-lg);
  z-index: var(--z-toast);
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.toast {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: 12px 16px;
  background: var(--toast-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--surface-border);
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-primary);
  animation: toast-enter 0.3s cubic-bezier(0.16, 1, 0.3, 1) forwards;
  max-width: 340px;
  box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

.toast.success {
  border-color: var(--positive-border);
}
.toast.error {
  border-color: var(--error-border);
}
.toast.exiting {
  animation: toast-exit 0.3s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

/* ── Keyframes ─────────────────────────────────────────────────────────── */
@keyframes card-enter {
  from {
    opacity: 0;
    transform: translateY(16px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes shimmer {
  0% {
    background-position: -200% 0;
  }
  100% {
    background-position: 200% 0;
  }
}

@keyframes spin {
  from {
    transform: rotate(0deg);
  }
  to {
    transform: rotate(360deg);
  }
}

@keyframes toast-enter {
  from {
    opacity: 0;
    transform: translateX(40px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes toast-exit {
  from {
    opacity: 1;
    transform: translateX(0);
  }
  to {
    opacity: 0;
    transform: translateX(40px);
  }
}

@keyframes pulse-glow {
  0%,
  100% {
    opacity: 1;
  }
  50% {
    opacity: 0.6;
  }
}

/* ── Responsive ────────────────────────────────────────────────────────── */
@media (max-width: 768px) {
  .main {
    padding: var(--space-md);
  }
  .header {
    padding: var(--space-md);
  }
  .header-title {
    font-size: 0.95rem;
  }
  .header-subtitle {
    font-size: 0.75rem;
  }
  .code-comparison {
    grid-template-columns: 1fr;
    padding-left: 0;
  }
  .card-description {
    padding-left: 0;
  }
  .editor-footer {
    flex-direction: column;
    gap: var(--space-sm);
    align-items: stretch;
  }
  .btn-review {
    justify-content: center;
  }
  .editor-hint {
    text-align: center;
  }
}

@media (max-width: 480px) {
  .editor-controls {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-xs);
  }
  .results-header {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-sm);
  }
}

/* ── Prism.js theme overrides ──────────────────────────────────────────── */
code[class*="language-"],
pre[class*="language-"] {
  font-family: var(--font-code) !important;
  font-size: 0.825rem !important;
  text-shadow: none !important;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}