/* ============================================
   CAConverter — Industrial-Utilitarian Design
   ============================================ */

/* --- CSS Variables --- */
:root {
  /* Base palette */
  --bg-primary: #0a0a0c;
  --bg-secondary: #111114;
  --bg-tertiary: #18181c;
  --bg-card: #141418;
  --bg-card-hover: #1a1a1f;
  --bg-elevated: #1e1e24;

  /* Accent — electric blue */
  --accent: #00d4ff;
  --accent-dim: #0099bb;
  --accent-glow: rgba(0, 212, 255, 0.15);
  --accent-glow-strong: rgba(0, 212, 255, 0.3);

  /* Text */
  --text-primary: #e8e8ec;
  --text-secondary: #888894;
  --text-tertiary: #55555f;
  --text-accent: var(--accent);

  /* Borders */
  --border: #2a2a32;
  --border-light: #333340;
  --border-accent: rgba(0, 212, 255, 0.3);

  /* Status */
  --success: #00e676;
  --warning: #ffc400;
  --error: #ff5252;

  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.4);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.5);
  --shadow-lg: 0 8px 32px rgba(0,0,0,0.6);
  --shadow-accent: 0 0 20px rgba(0, 212, 255, 0.1);

  /* Typography */
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', monospace;
  --font-display: 'Space Grotesk', 'Inter', system-ui, sans-serif;

  /* Spacing */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;
  --space-3xl: 64px;

  /* Radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;

  /* Transitions */
  --transition-fast: 120ms ease;
  --transition-base: 200ms ease;
  --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);
}

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

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

body {
  font-family: var(--font-mono);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  position: relative;
  overflow-x: hidden;
}

/* --- Noise Overlay --- */
.noise-overlay {
  position: fixed;
  inset: 0;
  z-index: 9999;
  pointer-events: none;
  opacity: 0.035;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noiseFilter'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noiseFilter)'/%3E%3C/svg%3E");
  background-repeat: repeat;
  background-size: 256px 256px;
}

/* --- Header --- */
.header {
  border-bottom: 1px solid var(--border);
  background: var(--bg-secondary);
  padding: var(--space-lg) var(--space-xl);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(12px);
  background: rgba(17, 17, 20, 0.9);
}

.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-md);
}

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

.logo-icon {
  color: var(--accent);
  font-size: 1.5rem;
  line-height: 1;
}

.logo-text {
  font-family: var(--font-display);
  font-size: 1.4rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--text-primary);
}

.accent {
  color: var(--accent);
}

.tagline {
  font-size: 0.7rem;
  color: var(--text-tertiary);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

/* --- Main --- */
.main {
  max-width: 1200px;
  margin: 0 auto;
  padding: var(--space-2xl) var(--space-xl);
  display: flex;
  flex-direction: column;
  gap: var(--space-xl);
}

/* --- Section Titles --- */
.section-title {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--text-secondary);
  margin-bottom: var(--space-md);
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.section-marker {
  color: var(--accent);
  font-weight: 400;
}

/* --- Settings Panel --- */
.settings-panel {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
}

.settings-row {
  display: flex;
  gap: var(--space-xl);
  flex-wrap: wrap;
  align-items: flex-start;
}

.setting-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  min-width: 160px;
}

.quality-group {
  flex: 1;
  min-width: 240px;
}

.setting-label {
  font-size: 0.7rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-secondary);
}

.quality-value {
  color: var(--accent);
  font-weight: 600;
}

.setting-select {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  background: var(--bg-tertiary);
  color: var(--text-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: var(--space-sm) var(--space-md);
  cursor: pointer;
  outline: none;
  transition: border-color var(--transition-fast);
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg width='10' height='6' viewBox='0 0 10 6' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M1 1l4 4 4-4' stroke='%23888894' stroke-width='1.5' fill='none' stroke-linecap='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  padding-right: 36px;
}

.setting-select:hover,
.setting-select:focus {
  border-color: var(--accent-dim);
}

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

/* Quality Slider */
.quality-slider {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 6px;
  border-radius: 3px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  outline: none;
  cursor: pointer;
  margin-top: var(--space-xs);
}

.quality-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid var(--bg-primary);
  box-shadow: 0 0 8px rgba(0, 212, 255, 0.4);
  cursor: pointer;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.quality-slider::-webkit-slider-thumb:hover {
  transform: scale(1.15);
  box-shadow: 0 0 14px rgba(0, 212, 255, 0.6);
}

.quality-slider::-moz-range-thumb {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid var(--bg-primary);
  box-shadow: 0 0 8px rgba(0, 212, 255, 0.4);
  cursor: pointer;
}

.slider-ticks {
  display: flex;
  justify-content: space-between;
  font-size: 0.6rem;
  color: var(--text-tertiary);
  margin-top: var(--space-xs);
  padding: 0 2px;
}

/* --- Drop Zone --- */
.drop-zone-wrapper {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-md);
}

.drop-zone {
  position: relative;
  border: 2px dashed var(--border-light);
  border-radius: var(--radius-lg);
  padding: var(--space-3xl) var(--space-xl);
  text-align: center;
  cursor: pointer;
  transition: all var(--transition-base);
  background: var(--bg-secondary);
  overflow: hidden;
}

.drop-zone::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse at center, var(--accent-glow) 0%, transparent 70%);
  opacity: 0;
  transition: opacity var(--transition-slow);
  pointer-events: none;
}

.drop-zone:hover,
.drop-zone.drag-over {
  border-color: var(--accent-dim);
  background: var(--bg-tertiary);
}

.drop-zone:hover::before,
.drop-zone.drag-over::before {
  opacity: 1;
}

.drop-zone:focus-visible {
  border-color: var(--accent);
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.file-input {
  position: absolute;
  inset: 0;
  opacity: 0;
  cursor: pointer;
  z-index: 1;
}

.drop-zone-content {
  position: relative;
  z-index: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-sm);
}

.drop-icon {
  color: var(--accent);
  margin-bottom: var(--space-sm);
  opacity: 0.7;
  transition: opacity var(--transition-base), transform var(--transition-base);
}

.drop-zone:hover .drop-icon {
  opacity: 1;
  transform: translateY(-2px);
}

.drop-text {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-primary);
}

.drop-subtext {
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.drop-browse {
  color: var(--accent);
  text-decoration: underline;
  text-underline-offset: 2px;
}

.drop-formats {
  font-size: 0.65rem;
  color: var(--text-tertiary);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-top: var(--space-sm);
}

/* --- Open Folder Button --- */
.btn-folder {
  background: var(--bg-secondary);
  border: 1px solid var(--border-light);
  color: var(--accent);
  padding: var(--space-sm) var(--space-lg);
  font-size: 0.78rem;
  letter-spacing: 0.06em;
}

.btn-folder:hover:not(:disabled) {
  background: var(--accent-glow);
  border-color: var(--accent);
  color: var(--accent);
  box-shadow: var(--shadow-accent);
}

/* --- Image Grid Section --- */
.section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-md);
}

.section-header .section-title {
  margin-bottom: 0;
}

.count-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 22px;
  height: 20px;
  padding: 0 6px;
  background: var(--accent-glow);
  color: var(--accent);
  border: 1px solid var(--border-accent);
  border-radius: 10px;
  font-size: 0.65rem;
  font-weight: 600;
}

/* --- Buttons --- */
.action-buttons {
  display: flex;
  gap: var(--space-sm);
  flex-wrap: wrap;
}

.btn {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  padding: var(--space-sm) var(--space-md);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  transition: all var(--transition-fast);
  background: var(--bg-tertiary);
  color: var(--text-secondary);
  text-transform: uppercase;
  white-space: nowrap;
}

.btn:hover:not(:disabled) {
  border-color: var(--border-light);
  color: var(--text-primary);
  background: var(--bg-elevated);
}

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

.btn-icon {
  font-size: 0.8rem;
}

.btn-convert {
  background: var(--accent);
  color: var(--bg-primary);
  border-color: var(--accent);
}

.btn-convert:hover:not(:disabled) {
  background: var(--accent-dim);
  border-color: var(--accent-dim);
  color: var(--bg-primary);
  box-shadow: var(--shadow-accent);
}

.btn-download {
  border-color: var(--accent-dim);
  color: var(--accent);
}

.btn-download:hover:not(:disabled) {
  background: var(--accent-glow);
  border-color: var(--accent);
  color: var(--accent);
}

.btn-clear {
  border-color: var(--border);
}

.btn-clear:hover:not(:disabled) {
  border-color: var(--error);
  color: var(--error);
  background: rgba(255, 82, 82, 0.08);
}

.btn-card {
  font-size: 0.6rem;
  padding: 4px 8px;
}

.btn-card.btn-card-convert {
  border-color: var(--accent-dim);
  color: var(--accent);
}

.btn-card.btn-card-download {
  border-color: var(--success);
  color: var(--success);
}

.btn-card.btn-card-remove {
  border-color: var(--border);
  color: var(--text-tertiary);
}

.btn-card.btn-card-remove:hover:not(:disabled) {
  border-color: var(--error);
  color: var(--error);
  background: rgba(255, 82, 82, 0.08);
}

/* --- Progress --- */
.progress-wrapper {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  margin-bottom: var(--space-md);
}

.progress-bar {
  flex: 1;
  height: 4px;
  background: var(--bg-tertiary);
  border-radius: 2px;
  overflow: hidden;
  border: 1px solid var(--border);
}

.progress-fill {
  height: 100%;
  width: 0%;
  background: var(--accent);
  border-radius: 2px;
  transition: width 200ms ease;
  box-shadow: 0 0 8px rgba(0, 212, 255, 0.4);
}

.progress-text {
  font-size: 0.68rem;
  color: var(--text-secondary);
  min-width: 50px;
  text-align: right;
}

/* --- Image Grid --- */
.image-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: var(--space-md);
}

/* --- Image Card --- */
.image-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: all var(--transition-base);
  position: relative;
  display: flex;
  flex-direction: column;
}

.image-card:hover {
  border-color: var(--border-light);
  box-shadow: var(--shadow-md);
}

.image-card.converted {
  border-color: var(--accent-dim);
}

.image-card.error {
  border-color: var(--error);
}

.card-preview {
  position: relative;
  width: 100%;
  aspect-ratio: 4/3;
  background: var(--bg-primary);
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}

.card-preview img {
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.card-preview .placeholder-icon {
  color: var(--text-tertiary);
  font-size: 2rem;
  opacity: 0.5;
}

.card-status {
  position: absolute;
  top: var(--space-sm);
  right: var(--space-sm);
  font-size: 0.55rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 2px 8px;
  border-radius: 3px;
  background: var(--bg-primary);
  border: 1px solid var(--border);
  color: var(--text-secondary);
}

.card-status.status-converting {
  border-color: var(--accent-dim);
  color: var(--accent);
  background: rgba(0, 212, 255, 0.1);
  animation: pulse 1s ease-in-out infinite;
}

.card-status.status-done {
  border-color: var(--success);
  color: var(--success);
  background: rgba(0, 230, 118, 0.1);
}

.card-status.status-error {
  border-color: var(--error);
  color: var(--error);
  background: rgba(255, 82, 82, 0.1);
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

.card-info {
  padding: var(--space-sm) var(--space-md);
  display: flex;
  flex-direction: column;
  gap: 2px;
  flex: 1;
}

.card-filename {
  font-size: 0.72rem;
  font-weight: 500;
  color: var(--text-primary);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.card-meta {
  font-size: 0.62rem;
  color: var(--text-tertiary);
  display: flex;
  gap: var(--space-sm);
  align-items: center;
}

.card-meta .separator {
  width: 3px;
  height: 3px;
  border-radius: 50%;
  background: var(--text-tertiary);
  display: inline-block;
}

.card-size-compare {
  font-size: 0.6rem;
  color: var(--text-secondary);
  padding: 2px 0;
  display: flex;
  gap: var(--space-xs);
  align-items: center;
}

.size-original {
  color: var(--text-tertiary);
  text-decoration: line-through;
}

.size-arrow {
  color: var(--accent);
  font-size: 0.55rem;
}

.size-converted {
  color: var(--accent);
  font-weight: 500;
}

.size-smaller {
  color: var(--success);
}

.size-larger {
  color: var(--warning);
}

.card-actions {
  padding: var(--space-sm) var(--space-md);
  border-top: 1px solid var(--border);
  display: flex;
  gap: var(--space-xs);
  flex-wrap: wrap;
}

/* --- Footer --- */
.footer {
  margin-top: var(--space-3xl);
  border-top: 1px solid var(--border);
  padding: var(--space-xl);
  text-align: center;
}

.footer-inner p {
  font-size: 0.65rem;
  color: var(--text-tertiary);
  letter-spacing: 0.04em;
}

.footer-tech {
  margin-top: var(--space-xs);
  font-size: 0.6rem !important;
  color: var(--text-tertiary) !important;
  opacity: 0.6;
}

/* --- Responsive --- */
@media (max-width: 768px) {
  .header-inner {
    flex-direction: column;
    align-items: flex-start;
  }

  .main {
    padding: var(--space-lg) var(--space-md);
  }

  .settings-row {
    flex-direction: column;
    gap: var(--space-md);
  }

  .setting-group {
    min-width: 100%;
  }

  .drop-zone {
    padding: var(--space-2xl) var(--space-md);
  }

  .section-header {
    flex-direction: column;
    align-items: flex-start;
  }

  .action-buttons {
    width: 100%;
    justify-content: flex-start;
  }

  .image-grid {
    grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  }
}

@media (max-width: 480px) {
  .image-grid {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-sm);
  }

  .card-info {
    padding: var(--space-xs) var(--space-sm);
  }

  .card-actions {
    padding: var(--space-xs) var(--space-sm);
  }

  .btn {
    font-size: 0.65rem;
    padding: 6px 10px;
  }

  .logo-text {
    font-size: 1.1rem;
  }
}

/* --- Utility --- */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
  border: 0;
}