/* ===== Theme Variables ===== */
:root,
[data-theme="light"] {
  --bg-primary: #ffffff;
  --bg-secondary: #f3f4f6;
  --bg-toolbar: rgba(255, 255, 255, 0.72);
  --bg-toolbar-solid: #ffffff;
  --text-primary: #1a1a2e;
  --text-secondary: #6b7280;
  --border-color: #e5e7eb;
  --divider-color: #d1d5db;
  --divider-hover: #9ca3af;
  --btn-bg: #ffffff;
  --btn-hover: #f9fafb;
  --btn-active: #f3f4f6;
  --btn-border: #e5e7eb;
  --toast-bg: #1f2937;
  --toast-text: #f9fafb;
  --pane-header-bg: #f9fafb;
  --error-color: #ef4444;
  --error-bg: #fef2f2;
  --accent: #6366f1;
  --accent-hover: #4f46e5;
  --accent-light: rgba(99, 102, 241, 0.08);
  --accent-glow: rgba(99, 102, 241, 0.35);
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.08), 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.08), 0 2px 4px -1px rgba(0, 0, 0, 0.04);
  --shadow-lg: 0 10px 25px -3px rgba(0, 0, 0, 0.1), 0 4px 10px -2px rgba(0, 0, 0, 0.04);
  --shadow-glow: 0 0 0 3px var(--accent-glow);
}

[data-theme="dark"] {
  --bg-primary: #0f1117;
  --bg-secondary: #1a1c25;
  --bg-toolbar: rgba(26, 28, 37, 0.78);
  --bg-toolbar-solid: #1a1c25;
  --text-primary: #e5e7eb;
  --text-secondary: #9ca3af;
  --border-color: #2d3040;
  --divider-color: #374151;
  --divider-hover: #6b7280;
  --btn-bg: #1e2030;
  --btn-hover: #262940;
  --btn-active: #2e3150;
  --btn-border: #2d3040;
  --toast-bg: #f3f4f6;
  --toast-text: #111827;
  --pane-header-bg: #161825;
  --error-color: #f87171;
  --error-bg: #1f1215;
  --accent: #818cf8;
  --accent-hover: #6366f1;
  --accent-light: rgba(129, 140, 248, 0.1);
  --accent-glow: rgba(129, 140, 248, 0.3);
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.2);
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.3), 0 1px 2px rgba(0, 0, 0, 0.2);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -1px rgba(0, 0, 0, 0.2);
  --shadow-lg: 0 10px 25px -3px rgba(0, 0, 0, 0.4), 0 4px 10px -2px rgba(0, 0, 0, 0.2);
  --shadow-glow: 0 0 0 3px var(--accent-glow);
}

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

html, body {
  height: 100%;
  overflow: hidden;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  transition: background 0.2s, color 0.2s;
}

/* ===== Toolbar ===== */
.toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 52px;
  padding: 0 16px;
  background: var(--bg-toolbar);
  backdrop-filter: blur(12px) saturate(180%);
  -webkit-backdrop-filter: blur(12px) saturate(180%);
  border-bottom: 1px solid var(--border-color);
  box-shadow: var(--shadow);
  z-index: 10;
  gap: 8px;
}

.toolbar-left {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}

.logo {
  font-size: 16px;
  font-weight: 700;
  white-space: nowrap;
  background: linear-gradient(135deg, #6366f1, #a78bfa);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.toolbar-right {
  display: flex;
  align-items: center;
  gap: 4px;
  flex-wrap: nowrap;
  overflow-x: auto;
}

.toolbar-right::-webkit-scrollbar {
  display: none;
}

.toolbar-divider {
  width: 1px;
  height: 24px;
  background: var(--border-color);
  margin: 0 4px;
  flex-shrink: 0;
}

.toolbar button {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 10px;
  border: 1px solid var(--btn-border);
  border-radius: 6px;
  background: var(--btn-bg);
  color: var(--text-primary);
  font-size: 13px;
  cursor: pointer;
  white-space: nowrap;
  transition: background 0.2s cubic-bezier(0.4, 0, 0.2, 1),
              border-color 0.2s cubic-bezier(0.4, 0, 0.2, 1),
              color 0.2s cubic-bezier(0.4, 0, 0.2, 1),
              transform 0.2s cubic-bezier(0.4, 0, 0.2, 1),
              box-shadow 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  flex-shrink: 0;
}

.toolbar button:hover {
  background: var(--btn-hover);
  border-color: var(--accent);
  color: var(--accent);
  transform: translateY(-1px);
}

.toolbar button:hover svg {
  transform: scale(1.1);
  transition: transform 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

.toolbar button:active {
  background: var(--btn-active);
  transform: translateY(0);
}

.toolbar button:focus-visible {
  outline: none;
  box-shadow: var(--shadow-glow);
}

.toolbar button svg {
  flex-shrink: 0;
  transition: transform 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

.toolbar select {
  padding: 6px 28px 6px 10px;
  border: 1px solid var(--btn-border);
  border-radius: 6px;
  background: var(--btn-bg);
  color: var(--text-primary);
  font-size: 13px;
  cursor: pointer;
  outline: none;
  appearance: none;
  -webkit-appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%236b7280' stroke-width='2'%3E%3Cpolyline points='6 9 12 15 18 9'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 8px center;
  transition: background-color 0.2s cubic-bezier(0.4, 0, 0.2, 1),
              border-color 0.2s cubic-bezier(0.4, 0, 0.2, 1),
              box-shadow 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  flex-shrink: 0;
}

.toolbar select:hover {
  background-color: var(--btn-hover);
}

.toolbar select:focus {
  border-color: var(--accent);
  box-shadow: var(--shadow-glow);
}

/* ===== Split Pane ===== */
.split-pane {
  display: flex;
  height: calc(100vh - 52px);
}

.pane {
  display: flex;
  flex-direction: column;
  min-width: 0;
  overflow: hidden;
}

.editor-pane {
  flex: 1 1 50%;
}

.preview-pane {
  flex: 1 1 50%;
}

.pane-header {
  display: flex;
  align-items: center;
  height: 32px;
  padding: 0 12px;
  font-size: 12px;
  font-weight: 600;
  color: var(--text-secondary);
  background: var(--pane-header-bg);
  border-bottom: 1px solid var(--border-color);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  flex-shrink: 0;
  position: relative;
}

.pane-header::after {
  content: '';
  position: absolute;
  bottom: -1px;
  left: 12px;
  width: 24px;
  height: 2px;
  background: var(--accent);
  opacity: 0.6;
  border-radius: 1px;
}

#editor {
  flex: 1;
  overflow: auto;
}

#editor .cm-editor {
  height: 100%;
}

#editor .cm-scroller {
  overflow: auto;
}

#preview {
  flex: 1;
  overflow: hidden;
  padding: 24px;
  position: relative;
  cursor: grab;
  background-color: var(--bg-primary);
  background-image:
    repeating-conic-gradient(var(--bg-secondary) 0% 25%, transparent 0% 50%);
  background-size: 20px 20px;
}

#preview.panning {
  cursor: grabbing;
}

#preview svg {
  transform-origin: 0 0;
}

#preview .error-message {
  color: var(--error-color);
  background: var(--error-bg);
  border: 1px solid var(--error-color);
  border-radius: 6px;
  padding: 16px;
  font-family: monospace;
  font-size: 13px;
  white-space: pre-wrap;
  word-break: break-word;
  width: 100%;
  max-width: 600px;
}

/* ===== Divider ===== */
.divider {
  width: 3px;
  cursor: col-resize;
  background: var(--divider-color);
  transition: background 0.2s cubic-bezier(0.4, 0, 0.2, 1),
              width 0.2s cubic-bezier(0.4, 0, 0.2, 1),
              box-shadow 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  flex-shrink: 0;
  position: relative;
}

.divider::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 3px;
  height: 24px;
  border-radius: 2px;
  background: rgba(255, 255, 255, 0.4);
  opacity: 0;
  transition: opacity 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  pointer-events: none;
}

.divider:hover,
.divider.active {
  background: var(--accent);
  width: 5px;
  box-shadow: 0 0 8px var(--accent-glow);
}

.divider:hover::after,
.divider.active::after {
  opacity: 1;
}

/* ===== Toast ===== */
.toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%) translateY(80px);
  background: var(--toast-bg);
  color: var(--toast-text);
  padding: 10px 20px;
  border-radius: 10px;
  font-size: 14px;
  pointer-events: none;
  opacity: 0;
  transition: transform 0.35s cubic-bezier(0.4, 0, 0.2, 1),
              opacity 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  z-index: 100;
  box-shadow: var(--shadow-lg);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* ===== PNG Size Inline Controls ===== */
.png-size-group {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
}

.png-size-label {
  font-size: 13px;
  color: var(--text-secondary);
  white-space: nowrap;
  font-weight: 500;
}

.png-size-toggle {
  display: flex;
  border: 1px solid var(--btn-border);
  border-radius: 6px;
  overflow: hidden;
}

.png-size-toggle .toggle-btn {
  padding: 4px 10px;
  font-size: 12px;
  font-weight: 500;
  border: none;
  border-radius: 0;
  background: var(--btn-bg);
  color: var(--text-secondary);
  cursor: pointer;
  transition: background 0.15s, color 0.15s;
  white-space: nowrap;
}

.png-size-toggle .toggle-btn:not(:last-child) {
  border-right: 1px solid var(--btn-border);
}

.png-size-toggle .toggle-btn:hover {
  background: var(--btn-hover);
  color: var(--text-primary);
  transform: none;
  border-color: transparent;
}

.png-size-toggle .toggle-btn.active {
  background: var(--accent);
  color: #ffffff;
}

.png-size-toggle .toggle-btn.active:hover {
  background: var(--accent-hover);
  color: #ffffff;
}

.png-size-input {
  width: 80px;
  padding: 4px 8px;
  border: 1px solid var(--btn-border);
  border-radius: 6px;
  background: var(--btn-bg);
  color: var(--text-primary);
  font-size: 13px;
  outline: none;
  transition: border-color 0.2s cubic-bezier(0.4, 0, 0.2, 1),
              box-shadow 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  flex-shrink: 0;
}

.png-size-input:focus {
  border-color: var(--accent);
  box-shadow: var(--shadow-glow);
}

/* Hide number input spin buttons */
.png-size-input::-webkit-outer-spin-button,
.png-size-input::-webkit-inner-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

.png-size-input {
  -moz-appearance: textfield;
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .toolbar {
    height: auto;
    min-height: 52px;
    flex-wrap: wrap;
    padding: 8px 16px;
    gap: 8px;
  }

  .toolbar button span {
    display: none;
  }

  .toolbar button {
    padding: 8px;
  }

  .split-pane {
    flex-direction: column;
    height: calc(100vh - 68px);
  }

  .divider {
    width: 100%;
    height: 3px;
    cursor: row-resize;
  }

  .divider:hover,
  .divider.active {
    width: 100%;
    height: 4px;
  }

  .divider::after {
    width: 24px;
    height: 3px;
    transform: translate(-50%, -50%);
  }

  .editor-pane,
  .preview-pane {
    flex: 1 1 50%;
  }

  .png-size-label {
    display: none;
  }
}