/* ============================================================
   HALFTONE GENERATOR 4.0 — STYLESHEET
   Dark, premium, professional UI
   ============================================================ */

:root {
  --bg-base:       #0a0a0f;
  --bg-surface:    #12121a;
  --bg-panel:      #16161f;
  --bg-card:       #1c1c28;
  --bg-hover:      #24243a;
  --border:        rgba(255,255,255,0.07);
  --border-strong: rgba(255,255,255,0.12);

  --accent:        #a78bfa;
  --accent-dim:    #7c3aed;
  --accent-glow:   rgba(167,139,250,0.15);
  --accent2:       #34d399;
  --accent3:       #f97316;

  --text-primary:  #f0f0f8;
  --text-secondary:#9090b0;
  --text-muted:    #505070;

  --sidebar-w:     280px;
  --toolbar-h:     48px;
  --infobar-h:     32px;
  --radius-sm:     6px;
  --radius-md:     10px;
  --radius-lg:     14px;

  --trans-fast:    120ms ease;
  --trans-med:     220ms ease;
  --trans-slow:    400ms cubic-bezier(.4,0,.2,1);

  font-size: 13px;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

body {
  font-family: 'Inter', system-ui, sans-serif;
  background: var(--bg-base);
  color: var(--text-primary);
  height: 100dvh;
  overflow: hidden;
  -webkit-font-smoothing: antialiased;
}

/* ── Layout ─────────────────────────────────────────────── */
#app {
  display: grid;
  grid-template-columns: var(--sidebar-w) 1fr;
  height: 100dvh;
}

/* ── Sidebar ─────────────────────────────────────────────── */
#sidebar {
  background: var(--bg-panel);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  height: 100dvh;
  overflow: hidden;
  position: relative;
  z-index: 10;
}

#sidebar::after {
  content: '';
  position: absolute;
  inset: 0 0 0 auto;
  width: 1px;
  background: linear-gradient(to bottom, transparent, var(--accent) 30%, var(--accent-dim) 70%, transparent);
  opacity: 0.3;
  pointer-events: none;
}

#sidebar-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 18px;
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}

#logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 16px;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text-primary);
}

#version-badge {
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.1em;
  background: linear-gradient(135deg, var(--accent-dim), var(--accent));
  color: white;
  padding: 2px 8px;
  border-radius: 20px;
}

#sidebar-content {
  flex: 1;
  overflow-y: auto;
  overflow-x: hidden;
  padding: 8px 0 16px;
  scrollbar-width: thin;
  scrollbar-color: var(--bg-hover) transparent;
}

#sidebar-content::-webkit-scrollbar { width: 4px; }
#sidebar-content::-webkit-scrollbar-thumb { background: var(--bg-hover); border-radius: 4px; }

.panel-section {
  padding: 12px 16px;
  border-bottom: 1px solid var(--border);
}

.panel-section:last-child { border-bottom: none; }

.section-label {
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 10px;
}

/* ── Drop Zone ───────────────────────────────────────────── */
.drop-zone {
  position: relative;
  border: 1.5px dashed var(--border-strong);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: border-color var(--trans-med), background var(--trans-med);
  overflow: hidden;
}

.drop-zone:hover, .drop-zone.dragover {
  border-color: var(--accent);
  background: var(--accent-glow);
}

.drop-zone-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 20px 16px;
  gap: 4px;
  pointer-events: none;
}

.upload-icon {
  width: 36px;
  height: 36px;
  color: var(--accent);
  margin-bottom: 4px;
  opacity: 0.8;
}

.drop-label {
  font-weight: 600;
  color: var(--text-secondary);
  font-size: 13px;
}

.drop-sub {
  font-size: 11px;
  color: var(--text-muted);
}

.drop-formats {
  margin-top: 6px;
  font-size: 10px;
  color: var(--text-muted);
  letter-spacing: 0.05em;
  font-family: 'JetBrains Mono', monospace;
}

#file-input {
  position: absolute;
  inset: 0;
  opacity: 0;
  cursor: pointer;
  width: 100%;
  height: 100%;
}

/* ── Presets ─────────────────────────────────────────────── */
#preset-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 6px;
}

.preset-btn {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-size: 11px;
  font-weight: 500;
  font-family: 'Inter', sans-serif;
  padding: 7px 8px;
  cursor: pointer;
  transition: all var(--trans-fast);
  text-align: center;
}

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

.preset-btn.active {
  background: var(--accent-glow);
  border-color: var(--accent);
  color: var(--accent);
}

/* ── Mode Toggle ─────────────────────────────────────────── */
#mode-toggle {
  display: flex;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.mode-btn {
  flex: 1;
  background: none;
  border: none;
  color: var(--text-muted);
  font-family: 'Inter', sans-serif;
  font-size: 12px;
  font-weight: 500;
  padding: 7px 4px;
  cursor: pointer;
  transition: all var(--trans-fast);
}

.mode-btn:hover { color: var(--text-primary); }
.mode-btn.active {
  background: var(--accent-dim);
  color: white;
}

/* ── Shape Grid ──────────────────────────────────────────── */
#shape-grid {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 4px;
}

.shape-btn {
  aspect-ratio: 1;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 6px;
  transition: all var(--trans-fast);
}

.shape-btn svg { width: 100%; height: 100%; }

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

.shape-btn.active {
  background: var(--accent-glow);
  border-color: var(--accent);
  color: var(--accent);
}

/* ── Controls ────────────────────────────────────────────── */
.controls-stack { display: flex; flex-direction: column; gap: 10px; }

.control-row {
  display: flex;
  flex-direction: column;
  gap: 5px;
}

.control-row label {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 12px;
  color: var(--text-secondary);
}

.ctrl-val {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  color: var(--accent);
  min-width: 32px;
  text-align: right;
}

input[type="range"] {
  -webkit-appearance: none;
  width: 100%;
  height: 4px;
  background: var(--bg-card);
  border-radius: 2px;
  outline: none;
  cursor: pointer;
  border: 1px solid var(--border);
  position: relative;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--accent);
  cursor: pointer;
  box-shadow: 0 0 8px var(--accent-glow);
  transition: transform var(--trans-fast);
}

input[type="range"]::-webkit-slider-thumb:hover {
  transform: scale(1.2);
}

input[type="range"]::-moz-range-thumb {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--accent);
  cursor: pointer;
  border: none;
}

/* ── Toggle ──────────────────────────────────────────────── */
.toggle-row {
  flex-direction: row !important;
  align-items: center;
  justify-content: space-between;
}

.toggle-row label:first-child {
  display: block;
  font-size: 12px;
  color: var(--text-secondary);
  justify-content: flex-start;
}

.toggle-switch {
  position: relative;
  display: inline-block;
  width: 36px;
  height: 20px;
  flex-shrink: 0;
}

.toggle-switch input { opacity: 0; width: 0; height: 0; }

.toggle-slider {
  position: absolute;
  inset: 0;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 20px;
  cursor: pointer;
  transition: background var(--trans-med);
}

.toggle-slider::before {
  content: '';
  position: absolute;
  width: 14px;
  height: 14px;
  left: 2px;
  top: 2px;
  background: var(--text-muted);
  border-radius: 50%;
  transition: transform var(--trans-med), background var(--trans-med);
}

.toggle-switch input:checked + .toggle-slider {
  background: var(--accent-glow);
  border-color: var(--accent);
}

.toggle-switch input:checked + .toggle-slider::before {
  transform: translateX(16px);
  background: var(--accent);
}

/* ── Color Rows ──────────────────────────────────────────── */
.color-row {
  flex-direction: row !important;
  align-items: center;
  justify-content: space-between;
}

.color-row label {
  font-size: 12px;
  color: var(--text-secondary);
  justify-content: flex-start;
}

input[type="color"] {
  width: 36px;
  height: 28px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: none;
  cursor: pointer;
  padding: 2px;
}

/* ── Export Buttons ──────────────────────────────────────── */
#export-btns {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 6px;
}

.export-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-family: 'Inter', sans-serif;
  font-size: 11px;
  font-weight: 600;
  padding: 10px 6px;
  cursor: pointer;
  transition: all var(--trans-fast);
}

.export-btn svg {
  width: 20px;
  height: 20px;
}

.export-btn:hover {
  border-color: var(--accent2);
  color: var(--accent2);
  background: rgba(52,211,153,0.08);
}

.export-btn:active { transform: scale(0.97); }

/* ── Export Name Preview ─────────────────────────────────── */
#filename-toggle-row {
  margin-bottom: 6px;
}

#export-name-row {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-bottom: 10px;
  font-size: 11px;
  color: var(--text-muted);
  font-family: 'JetBrains Mono', monospace;
  min-height: 20px;
}

#export-name-label {
  flex-shrink: 0;
}

#export-name-preview {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 2px 8px;
  color: var(--accent);
  font-size: 11px;
  font-family: 'JetBrains Mono', monospace;
  max-width: 140px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  transition: color var(--trans-fast), border-color var(--trans-fast);
}

#ctrl-keep-filename:checked ~ * #export-name-preview,
.toggle-switch input:checked ~ .toggle-slider {
  border-color: var(--accent);
}

/* ── Main Area ───────────────────────────────────────────── */
#main {
  display: flex;
  flex-direction: column;
  height: 100dvh;
  overflow: hidden;
  background: var(--bg-base);
}

/* ── Toolbar ─────────────────────────────────────────────── */
#toolbar {
  height: var(--toolbar-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 16px;
  border-bottom: 1px solid var(--border);
  background: var(--bg-surface);
  flex-shrink: 0;
  gap: 12px;
}

#toolbar-left, #toolbar-right {
  display: flex;
  align-items: center;
  gap: 12px;
}

#status-indicator {
  display: flex;
  align-items: center;
  gap: 7px;
  font-size: 12px;
  color: var(--text-secondary);
}

.dot-idle    { width:7px;height:7px;border-radius:50%;background:var(--text-muted); }
.dot-active  { width:7px;height:7px;border-radius:50%;background:var(--accent3);
               box-shadow:0 0 6px var(--accent3);animation:pulse 1s infinite; }
.dot-done    { width:7px;height:7px;border-radius:50%;background:var(--accent2);
               box-shadow:0 0 6px rgba(52,211,153,.5); }
.dot-error   { width:7px;height:7px;border-radius:50%;background:#f87171; }

@keyframes pulse {
  0%,100% { opacity:1; }
  50%      { opacity:.4; }
}

#zoom-controls {
  display: flex;
  align-items: center;
  gap: 4px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 2px;
}

.zoom-btn {
  background: none;
  border: none;
  color: var(--text-secondary);
  font-size: 16px;
  width: 26px;
  height: 26px;
  cursor: pointer;
  border-radius: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--trans-fast);
  font-family: monospace;
}

.zoom-btn:hover { background: var(--bg-hover); color: var(--text-primary); }

#zoom-label {
  font-size: 11px;
  font-family: 'JetBrains Mono', monospace;
  color: var(--text-secondary);
  min-width: 42px;
  text-align: center;
}

#view-toggle {
  display: flex;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.view-btn {
  background: none;
  border: none;
  color: var(--text-muted);
  font-family: 'Inter', sans-serif;
  font-size: 11px;
  font-weight: 500;
  padding: 5px 10px;
  cursor: pointer;
  transition: all var(--trans-fast);
}

.view-btn:hover { color: var(--text-primary); }
.view-btn.active {
  background: var(--accent-glow);
  color: var(--accent);
}

/* ── Canvas Wrap ─────────────────────────────────────────── */
#canvas-wrap {
  flex: 1;
  overflow: hidden;
  position: relative;
  cursor: grab;
  background:
    radial-gradient(circle at 20% 20%, rgba(124,58,237,.06) 0%, transparent 50%),
    radial-gradient(circle at 80% 80%, rgba(167,139,250,.04) 0%, transparent 50%),
    repeating-linear-gradient(
      0deg,
      transparent,
      transparent 24px,
      rgba(255,255,255,.015) 24px,
      rgba(255,255,255,.015) 25px
    ),
    repeating-linear-gradient(
      90deg,
      transparent,
      transparent 24px,
      rgba(255,255,255,.015) 24px,
      rgba(255,255,255,.015) 25px
    );
}

#canvas-wrap.grabbing { cursor: grabbing; }

#canvas-container {
  position: absolute;
  transform-origin: 0 0;
  will-change: transform;
}

#preview-canvas {
  display: block;
  image-rendering: pixelated;
}

#split-divider {
  position: absolute;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(to bottom, transparent, var(--accent), transparent);
  cursor: col-resize;
  z-index: 5;
}

#split-divider::before {
  content: '◀ ▶';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  background: var(--accent);
  color: white;
  font-size: 9px;
  padding: 4px 6px;
  border-radius: 20px;
  white-space: nowrap;
  letter-spacing: 0.05em;
}

/* ── Empty State ─────────────────────────────────────────── */
#empty-state {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
  pointer-events: none;
}

#empty-state.hidden { display: none; }

.empty-icon { margin-bottom: 8px; animation: float 4s ease-in-out infinite; }

@keyframes float {
  0%,100% { transform: translateY(0); }
  50%      { transform: translateY(-10px); }
}

#empty-state h2 {
  font-size: 22px;
  font-weight: 700;
  color: var(--text-secondary);
  letter-spacing: -0.03em;
}

#empty-state p {
  font-size: 13px;
  color: var(--text-muted);
  text-align: center;
  max-width: 300px;
  line-height: 1.6;
}

#empty-upload-btn {
  pointer-events: all;
  margin-top: 8px;
  background: linear-gradient(135deg, var(--accent-dim), var(--accent));
  border: none;
  border-radius: var(--radius-md);
  color: white;
  font-family: 'Inter', sans-serif;
  font-size: 13px;
  font-weight: 600;
  padding: 10px 24px;
  cursor: pointer;
  box-shadow: 0 4px 20px rgba(124,58,237,0.4);
  transition: all var(--trans-med);
}

#empty-upload-btn:hover {
  box-shadow: 0 6px 28px rgba(124,58,237,0.6);
  transform: translateY(-1px);
}

/* ── Info Bar ─────────────────────────────────────────────── */
#info-bar {
  height: var(--infobar-h);
  display: flex;
  align-items: center;
  padding: 0 16px;
  gap: 8px;
  border-top: 1px solid var(--border);
  background: var(--bg-surface);
  font-size: 11px;
  color: var(--text-muted);
  font-family: 'JetBrains Mono', monospace;
  flex-shrink: 0;
}

.info-sep { opacity: 0.4; }

/* ── Progress Overlay ────────────────────────────────────── */
#progress-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.6);
  backdrop-filter: blur(4px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
}

#progress-box {
  background: var(--bg-panel);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-lg);
  padding: 28px 36px;
  min-width: 320px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  box-shadow: 0 24px 60px rgba(0,0,0,0.5), 0 0 0 1px rgba(167,139,250,0.1);
}

#progress-title {
  font-size: 15px;
  font-weight: 600;
  color: var(--text-primary);
}

#progress-bar-wrap {
  height: 6px;
  background: var(--bg-card);
  border-radius: 3px;
  overflow: hidden;
}

#progress-bar {
  height: 100%;
  background: linear-gradient(90deg, var(--accent-dim), var(--accent));
  border-radius: 3px;
  width: 0%;
  transition: width 200ms ease;
  box-shadow: 0 0 12px var(--accent-glow);
}

#progress-sub {
  font-size: 12px;
  color: var(--text-muted);
  font-family: 'JetBrains Mono', monospace;
}

/* ── Responsive ──────────────────────────────────────────── */
@media (max-width: 700px) {
  :root { --sidebar-w: 100%; }
  #app { grid-template-columns: 1fr; grid-template-rows: auto 1fr; }
  #sidebar { height: auto; max-height: 40dvh; overflow-y: auto; }
}

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

/* ── Selection ───────────────────────────────────────────── */
::selection { background: var(--accent-glow); color: var(--accent); }