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

:root {
  --bg: #0a0a0b;
  --bg2: #141416;
  --bg3: #1e1e22;
  --bg4: #28282e;
  --text: #e4e4e7;
  --text2: #888;
  --text3: #555;
  --border: #2a2a30;
  --primary: #7c3aed;
  --primary-h: #8b5cf6;
  --accent: #06b6d4;
  --danger: #ef4444;
  --success: #22c55e;
  --r: 10px;
  --sidebar-w: 260px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'SF Pro', 'Segoe UI', sans-serif;
  background: var(--bg);
  color: var(--text);
  height: 100vh;
  overflow: hidden;
}

#app { display: flex; height: 100vh; }

/* === Sidebar === */
#sidebar {
  width: var(--sidebar-w);
  background: var(--bg2);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  flex-shrink: 0;
  overflow-y: auto;
}

.sidebar-header {
  padding: 18px 16px;
  border-bottom: 1px solid var(--border);
}
.sidebar-header h2 { font-size: 18px; font-weight: 700; }
.sidebar-header .subtitle { font-size: 11px; color: var(--text3); }

.sidebar-section {
  padding: 12px 14px;
  border-bottom: 1px solid var(--border);
}
.section-title {
  font-size: 11px;
  color: var(--text3);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 8px;
  font-weight: 600;
}

.size-options, .quality-options { display: flex; gap: 6px; }
.size-btn, .quality-btn {
  flex: 1;
  background: var(--bg3);
  border: 1px solid var(--border);
  color: var(--text2);
  padding: 8px 4px;
  border-radius: var(--r);
  cursor: pointer;
  font-size: 12px;
  text-align: center;
  transition: all 0.15s;
}
.size-btn small { display: block; font-size: 10px; color: var(--text3); margin-top: 2px; }
.size-btn:hover, .quality-btn:hover { background: var(--bg4); color: var(--text); }
.size-btn.active, .quality-btn.active {
  background: var(--primary);
  border-color: var(--primary);
  color: #fff;
}
.size-btn.active small { color: rgba(255,255,255,0.7); }

.preset-list { display: flex; flex-wrap: wrap; gap: 4px; }
.preset-btn {
  background: var(--bg3);
  border: 1px solid var(--border);
  color: var(--text2);
  padding: 5px 10px;
  border-radius: 16px;
  cursor: pointer;
  font-size: 11px;
  transition: all 0.15s;
}
.preset-btn:hover { background: var(--bg4); color: var(--text); }
.preset-btn.active {
  background: var(--primary);
  border-color: var(--primary);
  color: #fff;
}

#history-list {
  flex: 1;
  padding: 12px 14px;
  overflow-y: auto;
}

.history-item {
  padding: 8px 10px;
  border-radius: 6px;
  font-size: 12px;
  color: var(--text3);
  margin-bottom: 2px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.sidebar-footer {
  padding: 10px 14px;
  border-top: 1px solid var(--border);
}

/* === Main === */
#main {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
}

/* === Canvas === */
#canvas-area {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

#placeholder {
  text-align: center;
  color: var(--text3);
}
.placeholder-icon { font-size: 56px; margin-bottom: 14px; }
#placeholder p { font-size: 15px; margin-bottom: 6px; color: var(--text2); }
#placeholder .hint { font-size: 12px; color: var(--text3); }

#image-container {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  max-width: 92%;
  max-height: 92%;
}
#image-container.hidden { display: none; }

#main-image {
  max-width: 100%;
  max-height: calc(100vh - 180px);
  border-radius: var(--r);
  display: block;
  box-shadow: 0 8px 40px rgba(0,0,0,0.5);
}

#mask-canvas {
  position: absolute;
  top: 0; left: 0;
  border-radius: var(--r);
  pointer-events: none;
  opacity: 0;
  transition: opacity 0.2s;
}
#mask-canvas.active {
  pointer-events: auto;
  cursor: crosshair;
  opacity: 1;
}

#canvas-toolbar {
  position: absolute;
  bottom: -48px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 6px;
  align-items: center;
  background: var(--bg2);
  padding: 6px 14px;
  border-radius: 24px;
  border: 1px solid var(--border);
  white-space: nowrap;
}

.tool-btn {
  background: var(--bg3);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 5px 10px;
  border-radius: 16px;
  cursor: pointer;
  font-size: 12px;
  transition: all 0.15s;
  display: flex;
  align-items: center;
  gap: 4px;
}
.tool-btn:hover { background: var(--bg4); }
.tool-btn.active { background: var(--primary); border-color: var(--primary); }
.tool-slider input[type="range"] { width: 50px; accent-color: var(--primary); }
#brush-size-label { font-size: 10px; color: var(--text2); min-width: 20px; }
.tool-separator { width: 1px; height: 20px; background: var(--border); }

#mask-status { color: var(--accent); font-size: 11px; }
#mask-status.hidden { display: none; }

/* === Before/After === */
#compare-container {
  position: absolute;
  bottom: 60px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 8px;
  background: var(--bg2);
  padding: 8px;
  border-radius: var(--r);
  border: 1px solid var(--border);
  box-shadow: 0 4px 20px rgba(0,0,0,0.5);
  animation: fadeIn 0.3s;
}
#compare-container.hidden { display: none; }
#compare-container img { height: 120px; border-radius: 6px; }
.compare-label {
  position: absolute;
  top: 4px;
  font-size: 9px;
  padding: 2px 6px;
  border-radius: 4px;
  background: rgba(0,0,0,0.7);
}
.compare-before { left: 12px; color: var(--text2); }
.compare-after { right: 12px; color: var(--accent); }

/* === Chat === */
#chat-area {
  border-top: 1px solid var(--border);
  background: var(--bg2);
  max-height: 280px;
  display: flex;
  flex-direction: column;
}

#chat-messages {
  flex: 1;
  overflow-y: auto;
  padding: 10px 18px;
  display: none;
}
#chat-messages.visible { display: block; }

.chat-msg {
  margin-bottom: 8px;
  font-size: 13px;
  line-height: 1.4;
  display: flex;
  gap: 8px;
  align-items: flex-start;
}
.chat-msg .avatar {
  width: 24px; height: 24px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  flex-shrink: 0;
}
.chat-msg.user .avatar { background: var(--primary); }
.chat-msg.assistant .avatar { background: var(--accent); }
.chat-msg .content { flex: 1; color: var(--text); }

#input-area { padding: 10px 18px 14px; }

#preset-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--bg3);
  padding: 3px 10px;
  border-radius: 12px;
  font-size: 11px;
  color: var(--primary-h);
  margin-bottom: 6px;
}
#preset-badge.hidden { display: none; }
.preset-clear {
  background: none;
  border: none;
  color: var(--text3);
  cursor: pointer;
  font-size: 11px;
  padding: 0 2px;
}
.preset-clear:hover { color: var(--danger); }

.input-wrapper { display: flex; gap: 6px; align-items: flex-end; }

#prompt-input {
  flex: 1;
  background: var(--bg3);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 9px 14px;
  border-radius: 20px;
  font-size: 13px;
  resize: none;
  outline: none;
  font-family: inherit;
  max-height: 100px;
  min-height: 38px;
  line-height: 1.4;
}
#prompt-input:focus { border-color: var(--primary); }
#prompt-input::placeholder { color: var(--text3); }

.btn {
  border: none;
  padding: 7px 14px;
  border-radius: 18px;
  font-size: 13px;
  cursor: pointer;
  transition: all 0.15s;
  white-space: nowrap;
  height: 38px;
}
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-h); }
.btn-primary:disabled { opacity: 0.4; cursor: not-allowed; }
.btn-secondary { background: var(--bg3); color: var(--text2); border: 1px solid var(--border); }
.btn-secondary:hover { background: var(--bg4); color: var(--text); }
.btn-block { width: 100%; }

#mode-hint {
  font-size: 10px;
  color: var(--text3);
  margin-top: 5px;
  padding-left: 2px;
}

.hidden { display: none !important; }

@keyframes fadeIn { from { opacity: 0; transform: translateX(-50%) translateY(10px); } to { opacity: 1; transform: translateX(-50%) translateY(0); } }

::-webkit-scrollbar { width: 5px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }

@media (max-width: 768px) {
  #sidebar { display: none; }
  #canvas-toolbar { bottom: -42px; }
}