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

:root {
  --bg: #f5f5f5;
  --bg-panel: #ffffff;
  --bg-toolbar: #2c2c2c;
  --bg-status: #2c2c2c;
  --text: #333;
  --text-secondary: #666;
  --text-invert: #eee;
  --border: #ddd;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --accent-light: rgba(37, 99, 235, 0.08);
  --danger: #dc2626;
  --success: #16a34a;
  --shadow: 0 1px 4px rgba(0,0,0,0.1);
  --shadow-lg: 0 4px 16px rgba(0,0,0,0.12);
  --radius: 8px;
  --radius-sm: 4px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #1a1a2e;
    --bg-panel: #222244;
    --bg-toolbar: #111122;
    --bg-status: #111122;
    --text: #ddd;
    --text-secondary: #999;
    --text-invert: #eee;
    --border: #333366;
    --accent: #4f8cff;
    --accent-hover: #6aa0ff;
    --accent-light: rgba(79, 140, 255, 0.1);
    --shadow: 0 1px 4px rgba(0,0,0,0.3);
    --shadow-lg: 0 4px 16px rgba(0,0,0,0.4);
  }
}

html, body {
  height: 100%;
  font-family: -apple-system, "Segoe UI", "Noto Sans SC", sans-serif;
  background: var(--bg);
  color: var(--text);
}

body {
  display: grid;
  grid-template-rows: 44px 1fr 28px;
  grid-template-columns: 300px 1fr;
  overflow: hidden;
}

/* === Toolbar === */
#toolbar {
  grid-column: 1 / -1;
  background: var(--bg-toolbar);
  color: var(--text-invert);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 16px;
  font-size: 14px;
  z-index: 100;
}
#toolbar-title { font-weight: 600; font-size: 15px; }

/* === Sidebar === */
#sidebar {
  background: var(--bg-panel);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  z-index: 50;
}

#sidebar-tabs { display: flex; border-bottom: 1px solid var(--border); flex-shrink: 0; }
.sidebar-tab {
  flex: 1;
  padding: 10px 8px;
  border: none;
  background: transparent;
  color: var(--text-secondary);
  cursor: pointer;
  font-size: 12px;
  border-bottom: 2px solid transparent;
  transition: all .15s;
  white-space: nowrap;
}
.sidebar-tab.active { color: var(--accent); border-bottom-color: var(--accent); font-weight: 600; }
.sidebar-tab:hover { background: rgba(0,0,0,0.03); }

.sidebar-panel { display: none; flex: 1; overflow-y: auto; }
.sidebar-panel.active { display: flex; flex-direction: column; }

.panel-content { padding: 12px; display: flex; flex-direction: column; gap: 14px; }

.field-group { display: flex; flex-direction: column; gap: 6px; }
.field-group label { font-size: 13px; font-weight: 500; color: var(--text); }
.field-group input[type="number"],
.field-group select {
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 13px;
  background: var(--bg);
  color: var(--text);
  outline: none;
  width: 100%;
}
.field-group input[type="number"]:focus,
.field-group select:focus {
  border-color: var(--accent);
}
.field-group input[type="checkbox"] {
  width: 16px; height: 16px;
  accent-color: var(--accent);
}
.field-group input[type="range"] { accent-color: var(--accent); }

/* Buttons */
.btn-primary {
  padding: 10px 16px;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: background .15s;
  width: 100%;
}
.btn-primary:hover { background: var(--accent-hover); }
.btn-primary:disabled { opacity: 0.5; cursor: not-allowed; }

.btn-outline {
  padding: 10px 20px;
  background: transparent;
  color: var(--accent);
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  font-size: 14px;
  cursor: pointer;
  transition: all .15s;
}
.btn-outline:hover { border-color: var(--accent); background: var(--accent-light); }

/* Format options */
.format-options { display: flex; flex-direction: column; gap: 6px; }
.format-option {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 9px 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all .15s;
}
.format-option:hover { border-color: var(--accent); background: var(--accent-light); }
.format-option.selected { border-color: var(--accent); background: var(--accent-light); }
.format-option .format-icon { font-size: 20px; }
.format-option .format-name { font-weight: 600; font-size: 13px; }
.format-option .format-desc { font-size: 11px; color: var(--text-secondary); flex: 1; text-align: right; }

/* BG color options */
.bg-color-options { display: flex; gap: 8px; }
.bg-color-option {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: 13px;
  transition: all .15s;
}
.bg-color-option:hover { border-color: var(--accent); }
.bg-color-option.selected { border-color: var(--accent); background: var(--accent-light); }
.color-swatch {
  display: inline-block;
  width: 18px;
  height: 18px;
  border-radius: 50%;
}

/* Info callout */
.info-callout {
  padding: 12px;
  background: var(--accent-light);
  border: 1px solid var(--accent);
  border-radius: var(--radius-sm);
  font-size: 13px;
  line-height: 1.5;
  color: var(--text);
}

/* === Main Area === */
#main-area {
  background: var(--bg);
  overflow: auto;
  display: flex;
  flex-direction: column;
  position: relative;
}

/* Drop zone */
#drop-zone {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 20px;
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  transition: all .2s;
}
#drop-zone.drag-over { border-color: var(--accent); background: var(--accent-light); }
.drop-zone-content { text-align: center; padding: 40px; }
.drop-icon { font-size: 64px; margin-bottom: 16px; }
.drop-text { font-size: 18px; font-weight: 500; margin-bottom: 8px; }
.drop-hint { font-size: 13px; color: var(--text-secondary); margin-bottom: 20px; }

/* Preview area */
#preview-area { flex: 1; display: flex; flex-direction: column; overflow: hidden; }
#preview-toolbar {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 10px 20px;
  background: var(--bg-panel);
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}
#preview-toolbar button {
  padding: 6px 14px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 13px;
  cursor: pointer;
  color: var(--text);
}
#preview-toolbar button:hover { background: var(--border); }
#preview-info {
  display: flex;
  gap: 16px;
  font-size: 12px;
  color: var(--text-secondary);
  flex: 1;
}
#preview-info span { white-space: nowrap; }

#preview-container {
  flex: 1;
  display: flex;
  gap: 20px;
  padding: 20px;
  overflow: auto;
  align-items: flex-start;
  justify-content: center;
}

#preview-original, #preview-result {
  flex: 1;
  max-width: 48%;
  display: flex;
  flex-direction: column;
  align-items: center;
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
  box-shadow: var(--shadow);
}

#preview-arrow {
  font-size: 28px;
  align-self: center;
  flex-shrink: 0;
  color: var(--text-secondary);
}

.preview-label {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 10px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.preview-img-wrap {
  width: 100%;
  text-align: center;
  background: repeating-conic-gradient(#f0f0f0 0% 25%, transparent 0% 50%) 50% / 16px 16px;
  border-radius: var(--radius-sm);
  overflow: hidden;
  min-height: 100px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.preview-img-wrap img {
  max-width: 100%;
  max-height: 50vh;
  object-fit: contain;
  display: block;
}

.img-info {
  font-size: 11px;
  color: var(--text-secondary);
  margin-top: 8px;
  text-align: center;
}

#result-actions { margin-top: 12px; }
#result-actions .btn-primary { padding: 8px 24px; width: auto; }

/* === ID Photo Panel === */
#id-photo-panel {
  position: fixed;
  bottom: 36px;
  right: 16px;
  width: 260px;
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  z-index: 200;
  overflow: hidden;
}
#id-photo-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 12px;
  background: var(--accent);
  color: #fff;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
}
#id-photo-header button {
  background: transparent;
  border: none;
  color: #fff;
  cursor: pointer;
  font-size: 12px;
  transition: transform .2s;
}
#id-photo-panel.collapsed #id-photo-header button { transform: rotate(-90deg); }
#id-photo-body {
  padding: 12px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}
#id-photo-panel.collapsed #id-photo-body { display: none; }

/* === Status bar === */
#status-bar {
  grid-column: 1 / -1;
  background: var(--bg-status);
  color: var(--text-invert);
  display: flex;
  align-items: center;
  padding: 0 16px;
  font-size: 12px;
  z-index: 100;
}
#status-bar span { opacity: 0.8; }

/* === Scrollbar === */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: rgba(128,128,128,0.4); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: rgba(128,128,128,0.6); }

/* === Loading state === */
.loading {
  opacity: 0.6;
  pointer-events: none;
}

/* === Toast notification === */
.toast {
  position: fixed;
  top: 56px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--bg-toolbar);
  color: var(--text-invert);
  padding: 10px 24px;
  border-radius: var(--radius);
  font-size: 14px;
  z-index: 999;
  box-shadow: var(--shadow-lg);
  animation: toast-in .3s ease-out;
}
.toast.error { border-left: 4px solid var(--danger); }
.toast.success { border-left: 4px solid var(--success); }
@keyframes toast-in {
  from { opacity: 0; transform: translateX(-50%) translateY(-10px); }
  to { opacity: 1; transform: translateX(-50%) translateY(0); }
}