/* ========================================
   Pixel Snapper - Retro Pixel Art Style
   ======================================== */

:root {
  /* Color Palette - CRT Monitor Inspired */
  --bg-dark: #0a0a0f;
  --bg-panel: #12121a;
  --bg-surface: #1a1a26;
  --bg-elevated: #222233;
  
  --accent-primary: #00ff88;
  --accent-secondary: #00ccff;
  --accent-tertiary: #ff6b9d;
  --accent-warning: #ffcc00;
  
  --text-primary: #e8e8f0;
  --text-secondary: #a0a0b8;
  --text-muted: #606080;
  
  --border-color: #2a2a3f;
  --border-glow: rgba(0, 255, 136, 0.3);
  
  /* Typography */
  --font-mono: 'JetBrains Mono', 'Consolas', monospace;
  --font-sans: 'Noto Sans JP', system-ui, sans-serif;
  
  /* Spacing */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  
  /* Effects */
  --shadow-glow: 0 0 20px rgba(0, 255, 136, 0.15);
  --shadow-panel: 0 4px 24px rgba(0, 0, 0, 0.5);
  --transition: 0.2s 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;
}

[hidden] {
  display: none !important;
}

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

/* ========================================
   Background Effects
   ======================================== */

.scanlines {
  pointer-events: none;
  position: fixed;
  inset: 0;
  background: repeating-linear-gradient(
    0deg,
    transparent,
    transparent 2px,
    rgba(0, 0, 0, 0.1) 2px,
    rgba(0, 0, 0, 0.1) 4px
  );
  z-index: 1000;
  opacity: 0.3;
}

.grid-bg {
  pointer-events: none;
  position: fixed;
  inset: 0;
  background-image: 
    linear-gradient(rgba(0, 255, 136, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 255, 136, 0.03) 1px, transparent 1px);
  background-size: 32px 32px;
  z-index: -1;
}

/* ========================================
   Header
   ======================================== */

.header {
  text-align: center;
  padding: var(--space-xl) var(--space-md);
  background: linear-gradient(180deg, var(--bg-panel) 0%, transparent 100%);
  border-bottom: 1px solid var(--border-color);
}

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

.logo-icon {
  font-size: 2rem;
  animation: pulse 2s infinite;
}

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

.logo-text {
  font-family: var(--font-mono);
  font-size: 2rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  text-shadow: 0 0 30px rgba(0, 255, 136, 0.5);
}

.tagline {
  font-size: 0.95rem;
  color: var(--text-secondary);
  font-weight: 400;
}

/* ========================================
   Container
   ======================================== */

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: var(--space-xl) var(--space-md);
  position: relative;
}

/* ========================================
   Upload Section
   ======================================== */

.upload-section {
  margin-bottom: var(--space-xl);
}

.drop-zone {
  border: 2px dashed var(--border-color);
  border-radius: 12px;
  padding: var(--space-2xl);
  text-align: center;
  background: var(--bg-surface);
  transition: var(--transition);
  cursor: pointer;
}

.drop-zone:hover,
.drop-zone.drag-over {
  border-color: var(--accent-primary);
  background: rgba(0, 255, 136, 0.05);
  box-shadow: var(--shadow-glow);
}

.drop-icon {
  color: var(--text-muted);
  margin-bottom: var(--space-md);
  transition: var(--transition);
}

.drop-zone:hover .drop-icon {
  color: var(--accent-primary);
  transform: translateY(-4px);
}

.drop-text {
  font-size: 1.25rem;
  font-weight: 500;
  margin-bottom: var(--space-sm);
}

.drop-subtext {
  color: var(--text-muted);
  margin-bottom: var(--space-md);
}

.file-btn {
  display: inline-block;
  padding: var(--space-sm) var(--space-lg);
  background: var(--bg-elevated);
  border: 1px solid var(--border-color);
  border-radius: 6px;
  color: var(--text-primary);
  font-family: var(--font-mono);
  font-size: 0.9rem;
  cursor: pointer;
  transition: var(--transition);
}

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

.file-types {
  margin-top: var(--space-md);
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* ========================================
   Editor Section
   ======================================== */

.editor-section {
  animation: fadeIn 0.4s ease-out;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

.controls {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  gap: var(--space-lg);
  padding: var(--space-lg);
  background: var(--bg-panel);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  margin-bottom: var(--space-xl);
}

.control-group {
  flex: 1;
  min-width: 200px;
}

.control-label {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: var(--space-sm);
}

.label-icon {
  font-size: 1rem;
}

.value-badge {
  margin-left: auto;
  padding: 2px 8px;
  background: var(--accent-primary);
  color: var(--bg-dark);
  font-weight: 600;
  border-radius: 4px;
  font-size: 0.8rem;
}

.slider {
  width: 100%;
  height: 8px;
  -webkit-appearance: none;
  appearance: none;
  background: var(--bg-surface);
  border-radius: 4px;
  outline: none;
  cursor: pointer;
}

.slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 20px;
  height: 20px;
  background: var(--accent-primary);
  border-radius: 4px;
  cursor: grab;
  box-shadow: 0 0 10px var(--accent-primary);
  transition: var(--transition);
}

.slider::-webkit-slider-thumb:hover {
  transform: scale(1.1);
}

.slider::-webkit-slider-thumb:active {
  cursor: grabbing;
}

.slider::-moz-range-thumb {
  width: 20px;
  height: 20px;
  background: var(--accent-primary);
  border: none;
  border-radius: 4px;
  cursor: grab;
  box-shadow: 0 0 10px var(--accent-primary);
}

.slider-labels {
  display: flex;
  justify-content: space-between;
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: var(--space-xs);
  font-family: var(--font-mono);
}

.button-group {
  display: flex;
  gap: var(--space-sm);
}

/* ========================================
   Buttons
   ======================================== */

.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-lg);
  font-family: var(--font-mono);
  font-size: 0.9rem;
  font-weight: 600;
  border: 2px solid transparent;
  border-radius: 8px;
  cursor: pointer;
  transition: var(--transition);
  white-space: nowrap;
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn-icon {
  font-size: 1rem;
}

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

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

.btn-secondary {
  background: transparent;
  color: var(--text-secondary);
  border-color: var(--border-color);
}

.btn-secondary:hover:not(:disabled) {
  color: var(--accent-tertiary);
  border-color: var(--accent-tertiary);
}

.btn-download {
  background: linear-gradient(135deg, var(--accent-secondary), var(--accent-primary));
  color: var(--bg-dark);
  border: none;
  padding: var(--space-md) var(--space-xl);
  font-size: 1rem;
}

.btn-download:hover:not(:disabled) {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0, 204, 255, 0.3);
}

/* ========================================
   Preview Container
   ======================================== */

.preview-container {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: var(--space-lg);
  align-items: center;
}

@media (max-width: 768px) {
  .preview-container {
    grid-template-columns: 1fr;
  }
  
  .arrow-divider {
    transform: rotate(90deg);
  }
}

.preview-panel {
  background: var(--bg-panel);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  overflow: hidden;
}

.panel-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--space-sm) var(--space-md);
  background: var(--bg-surface);
  border-bottom: 1px solid var(--border-color);
}

.panel-title {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.panel-info {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
}

.preview-wrapper {
  aspect-ratio: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-md);
  background: 
    repeating-conic-gradient(
      var(--bg-surface) 0% 25%, 
      var(--bg-panel) 0% 50%
    ) 50% / 16px 16px;
  min-height: 300px;
  position: relative;
}

.preview-image {
  max-width: 100%;
  max-height: 100%;
  object-fit: contain;
  image-rendering: pixelated;
  image-rendering: crisp-edges;
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-panel);
}

.placeholder {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  height: 100%;
  min-height: 200px;
}

.placeholder-text {
  font-family: var(--font-mono);
  color: var(--text-muted);
  font-size: 0.9rem;
}

.arrow-divider {
  color: var(--accent-primary);
  animation: arrowPulse 1.5s infinite;
}

@keyframes arrowPulse {
  0%, 100% { opacity: 1; transform: translateX(0); }
  50% { opacity: 0.5; transform: translateX(4px); }
}

/* ========================================
   Download Section
   ======================================== */

.download-section {
  text-align: center;
  margin-top: var(--space-xl);
  animation: fadeIn 0.4s ease-out;
}

/* ========================================
   Loading Overlay
   ======================================== */

.loading-overlay {
  position: fixed;
  inset: 0;
  background: rgba(10, 10, 15, 0.9);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
  backdrop-filter: blur(8px);
}

.loading-content {
  text-align: center;
}

.loading-spinner {
  width: 64px;
  height: 64px;
  border: 4px solid var(--bg-surface);
  border-top-color: var(--accent-primary);
  border-radius: 50%;
  animation: spin 1s linear infinite;
  margin: 0 auto var(--space-lg);
}

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

.loading-text {
  font-family: var(--font-mono);
  font-size: 1.25rem;
  color: var(--accent-primary);
  margin-bottom: var(--space-sm);
}

.loading-subtext {
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* ========================================
   SEO Content Section
   ======================================== */

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

.seo-content {
  margin-bottom: var(--space-lg);
}

.features-brief {
  text-align: center;
}

.feature-tags {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-sm);
  list-style: none;
  padding: 0;
  margin: 0;
}

.feature-tags li {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: 20px;
  padding: var(--space-xs) var(--space-md);
  font-size: 0.85rem;
  color: var(--text-secondary);
  font-family: var(--font-mono);
}

.about-section {
  margin-top: var(--space-2xl);
  padding: var(--space-xl);
  background: var(--bg-panel);
  border: 1px solid var(--border-color);
  border-radius: 12px;
}

.about-section h2 {
  font-family: var(--font-mono);
  font-size: 1.5rem;
  color: var(--accent-primary);
  margin-bottom: var(--space-lg);
  text-align: center;
}

.about-content h3 {
  font-family: var(--font-mono);
  font-size: 1.1rem;
  color: var(--text-primary);
  margin: var(--space-lg) 0 var(--space-sm);
}

.about-content h3:first-child {
  margin-top: 0;
}

.about-content p {
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: var(--space-sm);
}

.about-content ul {
  color: var(--text-secondary);
  padding-left: var(--space-lg);
  margin-bottom: var(--space-md);
}

.about-content li {
  margin-bottom: var(--space-xs);
  line-height: 1.6;
}

.about-content strong {
  color: var(--accent-secondary);
}

/* ========================================
   Footer
   ======================================== */

.footer {
  text-align: center;
  padding: var(--space-xl) var(--space-md);
  border-top: 1px solid var(--border-color);
  margin-top: var(--space-2xl);
}

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

.footer a {
  color: var(--accent-secondary);
  text-decoration: none;
  transition: var(--transition);
}

.footer a:hover {
  color: var(--accent-primary);
  text-decoration: underline;
}

.footer .copyright {
  margin-top: var(--space-sm);
  opacity: 0.7;
}

.footer abbr {
  text-decoration: none;
  border-bottom: 1px dotted var(--text-muted);
  cursor: help;
}

/* ========================================
   Responsive
   ======================================== */

@media (max-width: 640px) {
  .logo-text {
    font-size: 1.5rem;
  }
  
  .controls {
    flex-direction: column;
    align-items: stretch;
  }
  
  .button-group {
    justify-content: center;
  }
  
  .preview-wrapper {
    min-height: 200px;
  }
}