/* ==========================================================================
   SLICE STYLING SYSTEM (Monochrome / Bauhaus / Glitch Grid)
   ========================================================================== */

:root {
  /* Colors */
  --bg-primary: #0a0a0a;
  --bg-secondary: #121212;
  --bg-tertiary: #1a1a1a;
  --fg-primary: #ffffff;
  --fg-secondary: #888888;
  --fg-tertiary: #555555;
  --border-color: #262626;
  --border-active: #ffffff;
  
  /* Typography */
  --font-sans: 'Outfit', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: 'Space Mono', monospace;
  
  /* Transitions */
  --transition-fast: 0.15s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-normal: 0.25s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-grid: 0.2s cubic-bezier(0.34, 1.56, 0.64, 1); /* Bouncy layout */
}

/* Base resets & theme */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  background-color: var(--bg-primary);
  color: var(--fg-primary);
  font-family: var(--font-sans);
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Custom scrollbars */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}
::-webkit-scrollbar-track {
  background: var(--bg-primary);
}
::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: 3px;
}
::-webkit-scrollbar-thumb:hover {
  background: var(--fg-tertiary);
}

/* Layout container */
.app-container {
  display: grid;
  grid-template-columns: 380px 1fr;
  width: 100%;
  min-height: 100vh;
  min-height: 100dvh;
}

@media (max-width: 900px) {
  .app-container {
    grid-template-columns: 1fr;
    grid-template-rows: auto 1fr;
  }
}

/* ==========================================================================
   LEFT PANEL: Controls
   ========================================================================== */
.controls-panel {
  background-color: var(--bg-secondary);
  border-right: 1px solid var(--border-color);
  padding: 40px;
  display: flex;
  flex-direction: column;
  gap: 32px;
  overflow-y: auto;
  max-height: 100vh;
  max-height: 100dvh;
}

@media (max-width: 900px) {
  .controls-panel {
    border-right: none;
    border-bottom: 1px solid var(--border-color);
    padding: 30px 20px;
    max-height: none;
  }
}

/* App Header */
.app-header {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.app-title {
  font-size: 2.2rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  line-height: 1;
}

.app-subtitle {
  font-size: 0.8rem;
  font-family: var(--font-mono);
  color: var(--fg-secondary);
  letter-spacing: 0.25em;
}

/* Upload Zone */
.upload-zone {
  border: 1px dashed var(--border-color);
  background-color: var(--bg-primary);
  border-radius: 4px;
  padding: 32px 20px;
  text-align: center;
  cursor: pointer;
  position: relative;
  transition: border-color var(--transition-normal), background-color var(--transition-normal);
}

.upload-zone:hover {
  border-color: var(--border-active);
  background-color: var(--bg-tertiary);
}

.upload-zone.dragover {
  border-color: var(--border-active);
  background-color: var(--bg-tertiary);
  transform: scale(0.98);
}

.file-input-hidden {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  opacity: 0;
  cursor: pointer;
}

.upload-prompt {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  pointer-events: none;
}

.upload-icon {
  width: 32px;
  height: 32px;
  color: var(--fg-secondary);
  transition: color var(--transition-normal), transform var(--transition-normal);
}

.upload-zone:hover .upload-icon {
  color: var(--fg-primary);
  transform: translateY(-2px);
}

.upload-text {
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0.1em;
}

.upload-subtext {
  font-size: 0.75rem;
  color: var(--fg-secondary);
  letter-spacing: 0.05em;
}

/* Dashboard Controls */
.dashboard {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.divider {
  border: none;
  border-top: 1px solid var(--border-color);
  margin: 4px 0;
}

.control-group {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.action-buttons {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

/* Buttons */
.btn {
  font-family: var(--font-sans);
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  padding: 14px 20px;
  border-radius: 4px;
  border: 1px solid transparent;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  transition: all var(--transition-normal);
  text-decoration: none;
  outline: none;
}

.btn-icon {
  font-size: 0.95rem;
}

.btn-primary {
  background-color: var(--fg-primary);
  color: var(--bg-primary);
}

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

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

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

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

/* Range Sliders */
.slider-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.control-label {
  font-size: 0.75rem;
  font-family: var(--font-mono);
  color: var(--fg-secondary);
  letter-spacing: 0.1em;
}

.control-value {
  font-size: 0.8rem;
  font-family: var(--font-mono);
  color: var(--fg-primary);
}

.range-slider {
  -webkit-appearance: none;
  width: 100%;
  height: 4px;
  background: var(--border-color);
  border-radius: 2px;
  outline: none;
  transition: background var(--transition-normal);
}

.range-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--fg-primary);
  cursor: pointer;
  transition: transform var(--transition-fast);
}

.range-slider::-webkit-slider-thumb:hover {
  transform: scale(1.2);
}

.range-slider::-moz-range-thumb {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--fg-primary);
  cursor: pointer;
  border: none;
  transition: transform var(--transition-fast);
}

.range-slider::-moz-range-thumb:hover {
  transform: scale(1.2);
}

/* Grid Size Control */
.grid-size-control {
  display: flex;
  align-items: center;
  gap: 12px;
}

.grid-size-number-input {
  width: 64px;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  background-color: var(--bg-primary);
  border: 1px solid var(--border-color);
  color: var(--fg-primary);
  padding: 8px 10px;
  border-radius: 4px;
  outline: none;
  text-align: center;
  transition: border-color var(--transition-normal), box-shadow var(--transition-normal);
}

.grid-size-number-input:focus {
  border-color: var(--border-active);
  box-shadow: 0 0 0 2px rgba(255, 255, 255, 0.1);
}

/* Remove arrows from number input */
.grid-size-number-input::-webkit-outer-spin-button,
.grid-size-number-input::-webkit-inner-spin-button {
  -webkit-appearance: none;
  margin: 0;
}
.grid-size-number-input[type=number] {
  -moz-appearance: textfield;
}

/* Footer */
.app-footer {
  margin-top: auto;
  font-size: 0.65rem;
  font-family: var(--font-mono);
  color: var(--fg-tertiary);
  letter-spacing: 0.1em;
}

@media (max-width: 900px) {
  .app-footer {
    margin-top: 20px;
  }
}

/* ==========================================================================
   RIGHT PANEL: Grid Display
   ========================================================================== */
.grid-display {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 40px;
  background-color: var(--bg-primary);
  position: relative;
}

@media (max-width: 900px) {
  .grid-display {
    padding: 20px;
  }
}

.grid-wrapper {
  width: 100%;
  max-width: 600px;
  aspect-ratio: 1 / 1;
  border: 1px solid var(--border-color);
  padding: 8px;
  background-color: var(--bg-secondary);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
}

.grid-container {
  display: grid;
  /* Columns and rows will be set dynamically via JS */
  width: 100%;
  height: 100%;
  gap: 0;
  position: relative;
  background-color: var(--bg-primary);
  overflow: hidden;
}

/* Grid Cells */
.grid-cell {
  grid-column: var(--col);
  grid-row: var(--row);
  background-image: var(--img-url);
  background-size: var(--perfect-size) var(--perfect-size);
  background-position: calc(-1 * (var(--orig-col) - 1) * var(--cell-size)) calc(-1 * (var(--orig-row) - 1) * var(--cell-size));
  background-repeat: no-repeat;
  width: calc(100% + 1px);
  height: calc(100% + 1px);
  transform-origin: center center;
  transition: 
    transform var(--transition-grid),
    opacity var(--transition-normal),
    filter var(--transition-normal);
  will-change: transform, opacity, grid-column, grid-row;
}

/* Hidden cell state */
.grid-cell.hidden {
  opacity: 0;
  transform: scale(0.0) rotate(15deg);
  pointer-events: none;
}

/* Transition to scramble mode (no transition during rapid shuffle) */
.grid-container.scrambling .grid-cell {
  /* Remove transition of grid pos for instant performance updates */
  transition: transform 0.05s ease-out, opacity 0.05s ease-out;
}

/* Hover effects for grid cells when solved (idle) */
.grid-container.idle .grid-cell:hover {
  outline: 1px solid #ffffff;
  z-index: 10;
  transform: scale(1.05);
}