/* ==================== Base & Reset ==================== */
.overflow-hidden { overflow: hidden; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); border: 0; }
.hidden { display: none !important; }

/* Utility classes */
.mb-2 { margin-bottom: .5rem; }
.mb-4 { margin-bottom: 1rem; }
.mb-6 { margin-bottom: 1.5rem; }
.mt-4 { margin-top: 1rem; }
.pt-4 { padding-top: 1rem; }
.border-t { border-top-width: 1px; border-top-style: solid; }
.border-gray-200 { border-color: var(--border-color); }
.w-full { width: 100%; }
.w-16 { width: 4rem; }
.text-center { text-align: center; }
.text-sm { font-size: .875rem; line-height: 1.25rem; }
.text-muted { color: var(--text-muted); }
.p-1 { padding: .25rem; }
.p-2 { padding: .5rem; }
.border { border-width: 1px; border-style: solid; border-color: var(--border-color); }
.rounded { border-radius: var(--radius-sm); }
.font-medium { font-weight: 500; }
.font-bold { font-weight: 700; }
.grid { display: grid; }
.grid-cols-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid-cols-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid-cols-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.grid-cols-5 { grid-template-columns: repeat(5, minmax(0, 1fr)); }
.gap-2 { gap: .5rem; }
.gap-3 { gap: .75rem; }
.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.space-y-3 > :not([hidden]) ~ :not([hidden]) { margin-top: .75rem; }
.space-y-4 > * + * { margin-top: 1rem; }
.cursor-pointer { cursor: pointer; }
.select-none { user-select: none; }
.block { display: block; }

/* ==================== CSS Variables ==================== */
:root {
  --font-sans: "Sora", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: "JetBrains Mono", "SF Mono", "Consolas", monospace;
  --bg-main: #f5f3fa;
  --bg-deep: #edeaf5;
  --bg-sidebar: rgba(255, 255, 255, 0.75);
  --bg-nav: rgba(255, 255, 255, 0.85);
  --bg-panel: rgba(139, 92, 246, 0.02);
  --bg-card: rgba(139, 92, 246, 0.04);
  --bg-input: rgba(139, 92, 246, 0.04);
  --text-primary: #1a1a2e;
  --text-secondary: #4a4a6a;
  --text-muted: #94a3b8;
  --border-color: rgba(139, 92, 246, 0.14);
  --border-hover: rgba(139, 92, 246, 0.3);
  --primary-accent: #8b5cf6;
  --primary-accent-hover: #7c3aed;
  --secondary-accent: #ec4899;
  --accent-gradient: linear-gradient(135deg, #8b5cf6, #ec4899);
  --accent-glow: 0 0 20px rgba(139, 92, 246, 0.25);
  --danger: #ef4444;
  --danger-bg: rgba(239, 68, 68, 0.08);
  --success: #10b981;
  --nav-height: 64px;
  --sidebar-width: 320px;
  --shadow-sm: 0 2px 8px rgba(139, 92, 246, 0.08);
  --shadow-md: 0 8px 32px rgba(139, 92, 246, 0.12);
  --shadow-glow: 0 0 30px rgba(139, 92, 246, 0.1);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 20px;
  --glass-blur: blur(24px);
}

/* ==================== Global ==================== */
*, *:before, *:after { box-sizing: border-box; }

body {
  font-family: var(--font-sans);
  background-color: var(--bg-main);
  color: var(--text-secondary);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  margin: 0;
  padding: 0;
  background-image:
    radial-gradient(ellipse at 20% 0%, rgba(139, 92, 246, 0.06) 0%, transparent 50%),
    radial-gradient(ellipse at 80% 100%, rgba(236, 72, 153, 0.05) 0%, transparent 50%);
}

body.overflow-hidden { overflow: hidden; }

input[type=file] { display: none; }

/* Scrollbar styling */
::-webkit-scrollbar { width: 8px; height: 8px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: rgba(139, 92, 246, 0.15); border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: rgba(139, 92, 246, 0.3); }

/* ==================== Decorative Background Glows ==================== */
.bg-glow {
  position: fixed;
  border-radius: 50%;
  filter: blur(100px);
  z-index: 0;
  pointer-events: none;
  opacity: 0.3;
}
.glow-1 {
  width: 500px; height: 500px;
  top: -200px; left: -100px;
  background: radial-gradient(circle, rgba(139, 92, 246, 0.25), transparent 70%);
  animation: glow-float-1 12s ease-in-out infinite alternate;
}
.glow-2 {
  width: 400px; height: 400px;
  bottom: -150px; right: -100px;
  background: radial-gradient(circle, rgba(236, 72, 153, 0.15), transparent 70%);
  animation: glow-float-2 15s ease-in-out infinite alternate;
}
@keyframes glow-float-1 {
  0% { transform: translate(0, 0); }
  100% { transform: translate(100px, 80px); }
}
@keyframes glow-float-2 {
  0% { transform: translate(0, 0); }
  100% { transform: translate(-80px, -60px); }
}

/* ==================== Toast ==================== */
#toast {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 9999;
  padding: 14px 24px;
  border-radius: var(--radius-md);
  box-shadow: 0 8px 32px rgba(139, 92, 246, .2);
  font-size: 14px;
  font-weight: 500;
  opacity: 0;
  visibility: hidden;
  transition: opacity .3s ease, visibility .3s linear .3s, transform .3s ease;
  transform: translateY(20px);
  pointer-events: none;
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--border-color);
}
#toast.show {
  opacity: 1; visibility: visible;
  transition: opacity .3s ease, visibility 0s, transform .3s ease;
  transform: translateY(0);
}
#toast.success { background-color: rgba(16, 185, 129, 0.92); color: #fff; }
#toast.info { background-color: rgba(139, 92, 246, 0.92); color: #fff; }
#toast.error { background-color: rgba(239, 68, 68, 0.92); color: #fff; }
#toast.warning { background-color: rgba(245, 158, 11, 0.92); color: #1a1a2e; }

/* ==================== Navigation ==================== */
.glass-nav {
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  background-color: var(--bg-nav) !important;
  border-bottom: 1px solid var(--border-color) !important;
}

#app-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--nav-height);
  padding: 0 28px;
  background-color: var(--bg-nav);
  width: 100%;
  position: fixed;
  top: 0;
  left: 0;
  z-index: 1001;
  box-shadow: 0 4px 24px rgba(139, 92, 246, 0.06);
  border-bottom: 1px solid var(--border-color);
}

.nav-title {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text-primary);
}
.nav-title a {
  color: var(--text-primary);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 10px;
}
.nav-title svg { flex-shrink: 0; }
.nav-brand-text {
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.nav-links {
  display: flex;
  gap: 24px;
  align-items: center;
}
.nav-links a {
  font-size: .875rem;
  font-weight: 500;
  color: var(--text-secondary);
  text-decoration: none;
  transition: color .2s ease;
  position: relative;
}
.nav-links a:hover { color: var(--text-primary); }
.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px; left: 0;
  width: 0; height: 2px;
  background: var(--accent-gradient);
  border-radius: 2px;
  transition: width .25s ease;
}
.nav-links a:hover::after { width: 100%; }

.nav-pro-link {
  padding: 4px 12px !important;
  background: var(--accent-gradient);
  color: #fff !important;
  border-radius: 20px;
  font-weight: 600;
  font-size: .75rem !important;
  letter-spacing: 0.05em;
}
.nav-pro-link::after { display: none; }

/* Tools dropdown */
.tools-link-btn {
  display: flex;
  align-items: center;
  padding: 8px 14px;
  cursor: pointer;
  background: rgba(139, 92, 246, 0.06);
  color: var(--text-primary) !important;
  border: 1px solid var(--border-color);
  border-radius: 20px;
  font-weight: 600;
  text-decoration: none;
  transition: all .2s ease;
  font-size: .85rem;
}
.tools-link-btn:hover {
  background: rgba(139, 92, 246, 0.1);
  border-color: var(--primary-accent);
  box-shadow: var(--accent-glow);
}
.tools-link-btn svg { width: 1rem; height: 1rem; margin-right: 6px; stroke: currentColor; stroke-width: 2.5; }

#tools-dropdown-container { position: relative; height: 100%; display: flex; align-items: center; }

.dropdown-menu {
  position: absolute;
  top: calc(var(--nav-height) - 1px);
  right: 0;
  width: 380px;
  max-height: calc(100vh - var(--nav-height) - 2rem);
  overflow-y: auto;
  background-color: rgba(255, 255, 255, 0.92);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  z-index: 1000;
  padding: 1rem;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-10px);
  transition: opacity .2s ease, transform .2s ease, visibility .2s;
}
.dropdown-menu.visible { opacity: 1; visibility: visible; transform: translateY(0); }

.menu-title {
  font-size: .85rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: .75rem;
  padding-bottom: .5rem;
  border-bottom: 1px solid var(--border-color);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.tool-items-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: .75rem;
}
.tool-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 12px;
  background-color: rgba(139, 92, 246, 0.03);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  text-decoration: none;
  transition: all .2s ease;
  cursor: pointer;
}
.tool-item:hover {
  background-color: rgba(139, 92, 246, 0.06);
  border-color: var(--primary-accent);
  transform: translateY(-2px);
}
.tool-item span { font-size: .78rem; font-weight: 500; color: var(--text-secondary); margin-top: 6px; }
.tool-item svg { width: 28px; height: 28px; color: var(--primary-accent); stroke-width: 1.8; }
.tool-item.current-tool {
  background: rgba(139, 92, 246, 0.08);
  border-color: var(--primary-accent);
  box-shadow: var(--accent-glow);
}
.tool-item.current-tool span { color: var(--primary-accent); font-weight: 600; }

/* Mobile nav buttons */
.mobile-nav-btn { display: none; background: none; border: none; padding: 4px; color: var(--text-primary); cursor: pointer; }

/* ==================== App Container ==================== */
#app-container {
  display: flex;
  height: 100vh;
  padding-top: var(--nav-height);
  position: relative;
  overflow-x: hidden;
}

/* ==================== Sidebars ==================== */
.glass-panel {
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
}

#left-sidebar, #right-sidebar {
  width: var(--sidebar-width);
  flex-shrink: 0;
  background-color: var(--bg-sidebar);
  position: relative;
  transition: all .3s ease-in-out;
  height: calc(100vh - var(--nav-height));
  display: flex;
  flex-direction: column;
  z-index: 10;
}
#left-sidebar { border-right: 1px solid var(--border-color); }
#right-sidebar { border-left: 1px solid var(--border-color); }

.sidebar-content-wrapper {
  width: 100%;
  padding: 1.5rem;
  overflow-y: auto;
  flex: 1;
  min-height: 0;
  position: relative;
}

/* Reset button */
#reset-settings-btn {
  position: absolute;
  top: .75rem;
  right: .75rem;
  z-index: 10;
  background: rgba(139, 92, 246, 0.06);
  border: 1px solid var(--border-color);
  padding: 6px;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  transition: all .2s ease;
}
#reset-settings-btn:hover {
  color: var(--primary-accent);
  background: rgba(139, 92, 246, 0.1);
  border-color: var(--primary-accent);
  transform: rotate(-180deg);
}

/* ==================== Panel ==================== */
.panel { background-color: transparent; border: none; box-shadow: none; padding: 0; }

.panel-section-title {
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 1rem;
  padding-bottom: .75rem;
  border-bottom: 1px solid var(--border-color);
  font-size: .8rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  cursor: pointer;
  list-style: none;
  position: relative;
  padding-left: 14px;
}
.panel-section-title::before {
  content: '';
  position: absolute;
  left: 0; top: 2px;
  width: 3px; height: 16px;
  background: var(--accent-gradient);
  border-radius: 2px;
}
.panel-section-title::-webkit-details-marker { display: none; }
.panel-section-title::marker { display: none; }

/* Details/Summary */
.panel details > summary { position: relative; }
.panel details > summary::-webkit-details-marker { display: none; }

.panel details[open] > summary {
  margin-bottom: 0;
}
.panel details[open] > .pt-4 {
  animation: panel-fade-in .3s ease;
}
@keyframes panel-fade-in {
  from { opacity: 0; transform: translateY(-8px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ==================== Layout Thumbnails ==================== */
.layout-group-title {
  font-weight: 600;
  color: var(--text-secondary);
  margin-top: 1.5rem;
  margin-bottom: .75rem;
  padding-bottom: 0;
  border-bottom: none;
  font-size: .8rem;
  letter-spacing: 0.02em;
}
.layout-group-title:first-child { margin-top: 0; }

.layout-thumbnail-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: .75rem;
}

.layout-thumbnail {
  border-radius: var(--radius-sm);
  background-color: rgba(139, 92, 246, 0.03);
  border: 1px solid var(--border-color);
  cursor: pointer;
  padding: 6px;
  transition: all .2s ease;
  position: relative;
  overflow: hidden;
}

.layout-thumbnail:hover {
  border-color: var(--border-hover);
  background-color: rgba(139, 92, 246, 0.06);
  transform: translateY(-2px);
}
.layout-thumbnail.active {
  border-color: var(--primary-accent);
  background-color: rgba(139, 92, 246, 0.08);
  box-shadow: 0 0 12px rgba(139, 92, 246, 0.2);
}

.thumbnail-grid {
  display: grid;
  width: 100%;
  aspect-ratio: 1 / 1;
  gap: 3px;
}
.thumbnail-cell {
  background-color: rgba(139, 92, 246, 0.2);
  border-radius: 2px;
  transition: background-color .2s;
}
.layout-thumbnail:hover .thumbnail-cell { background-color: rgba(139, 92, 246, 0.35); }
.layout-thumbnail.active .thumbnail-cell {
  background: var(--accent-gradient);
}

/* ==================== Center Content ==================== */
#center-content {
  flex: 1;
  display: grid;
  grid-template-rows: auto 1fr;
  justify-items: center;
  padding: 1.5rem 2rem;
  height: calc(100vh - var(--nav-height));
  overflow: hidden;
  position: relative;
  z-index: 1;
}

#canvas-viewport {
  width: 100%;
  height: 100%;
  overflow: auto;
  display: grid;
  justify-items: center;
  align-items: center;
  position: relative;
  background-image: radial-gradient(circle at 1px 1px, rgba(139, 92, 246, 0.07) 1px, transparent 0);
  background-size: 24px 24px;
  border-radius: var(--radius-lg);
}

.collage-wrapper {
  background-color: #fff;
  border-radius: var(--radius-md);
  box-shadow: 0 8px 40px rgba(139, 92, 246, 0.1), 0 0 60px rgba(139, 92, 246, 0.05);
  position: relative;
  overflow: hidden;
}

#layout-wrapper {
  display: flex;
  width: 100%;
  max-height: 100%;
  position: relative;
}

#layout-grid {
  flex: 1;
  display: grid;
  position: relative;
}

#annotation-layer {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 5;
}
#annotation-layer > * { pointer-events: auto; }

/* ==================== Canvas Action Toolbar ==================== */
.glass-toolbar {
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  background-color: rgba(255, 255, 255, 0.7) !important;
  border: 1px solid var(--border-color) !important;
}

#canvas-action-toolbar {
  display: flex;
  justify-content: flex-start;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 16px;
  padding: 8px;
  background-color: rgba(255, 255, 255, 0.7);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
  width: 100%;
  max-width: 900px;
}

.toolbar-group-left { display: flex; align-items: center; gap: 8px; }
.toolbar-group-right { margin-left: auto; display: flex; align-items: center; gap: 8px; }
.toolbar-divider { width: 1px; height: 24px; background: var(--border-color); margin: 0 4px; flex-shrink: 0; }

#canvas-action-toolbar .action-button {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 8px 14px;
  font-size: 13px;
  font-weight: 500;
}

/* ==================== Action Buttons ==================== */
.action-button {
  font-size: .875rem;
  font-weight: 500;
  padding: .625rem 1rem;
  border-radius: var(--radius-sm);
  transition: all .2s ease;
  border: 1px solid var(--border-color);
  text-align: center;
  cursor: pointer;
  background: rgba(139, 92, 246, 0.04);
  color: var(--text-secondary);
  font-family: inherit;
  position: relative;
  overflow: hidden;
}
.action-button:hover {
  background: rgba(139, 92, 246, 0.08);
  border-color: var(--border-hover);
  color: var(--text-primary);
  transform: translateY(-1px);
}
.action-button:active { transform: translateY(0); }

.icon-btn {
  border-radius: 20px;
  padding: 8px 14px;
}

.gradient-btn {
  background: var(--accent-gradient);
  color: #fff;
  border: none;
  font-weight: 600;
}
.gradient-btn:hover {
  background: var(--accent-gradient);
  box-shadow: var(--accent-glow);
  transform: translateY(-1px);
  color: #fff;
}

#download-btn { background: var(--accent-gradient); color: #fff; border: none; font-weight: 600; }
#download-btn:hover { background: var(--accent-gradient); box-shadow: var(--accent-glow); color: #fff; }

#batch-upload-btn {
  background: rgba(139, 92, 246, 0.08);
  color: var(--primary-accent);
  border: 1px solid var(--border-color);
  font-weight: 600;
}
#batch-upload-btn:hover {
  background: rgba(139, 92, 246, 0.12);
  border-color: var(--primary-accent);
  box-shadow: var(--accent-glow);
  color: var(--primary-accent);
}

#shuffle-btn, .action-button.secondary {
  background: rgba(139, 92, 246, 0.04);
  color: var(--text-secondary);
  border: 1px solid var(--border-color);
}
#shuffle-btn:hover, .action-button.secondary:hover {
  background: rgba(139, 92, 246, 0.08);
  border-color: var(--border-hover);
  color: var(--text-primary);
}

.action-button.danger {
  background: var(--danger-bg);
  color: var(--danger);
  border: 1px solid rgba(239, 68, 68, 0.2);
}
.action-button.danger:hover {
  background: rgba(239, 68, 68, 0.12);
  color: var(--danger);
  border-color: rgba(239, 68, 68, 0.4);
}

#right-sidebar button, #stitching-direction-btns button {
  padding: .5rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
  font-weight: 500;
  transition: all .2s ease;
  cursor: pointer;
  background: rgba(139, 92, 246, 0.03);
  color: var(--text-secondary);
  font-family: inherit;
  font-size: .875rem;
}
#right-sidebar button:hover {
  background: rgba(139, 92, 246, 0.07);
  border-color: var(--border-hover);
  color: var(--text-primary);
}
#right-sidebar button.active {
  background: rgba(139, 92, 246, 0.1);
  color: var(--primary-accent);
  border-color: var(--primary-accent);
  font-weight: 600;
  box-shadow: 0 0 12px rgba(139, 92, 246, 0.15);
}
#aspect-ratio-btns button:hover { background: rgba(139, 92, 246, 0.07); }

#aspect-ratio-btns button[data-print] {
  padding: .35rem .25rem;
  font-size: .8rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  line-height: 1.15;
}
#aspect-ratio-btns button[data-print] .ratio-sub { font-size: .58rem; font-weight: 400; color: var(--text-muted); }
#aspect-ratio-btns button[data-print].active .ratio-sub { color: var(--primary-accent); }

.print-ratio-divider {
  display: flex;
  align-items: center;
  gap: .5rem;
  font-size: .7rem;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: .2rem 0;
  margin-top: .15rem;
  user-select: none;
  pointer-events: none;
}
.print-ratio-divider:before, .print-ratio-divider:after {
  content: "";
  flex: 1;
  border-top: 1px dashed var(--border-color);
}

/* ==================== Inputs ==================== */
label { font-size: .875rem; font-weight: 500; color: var(--text-secondary); text-align: left; display: block; }

input[type=range] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 4px;
  background: rgba(139, 92, 246, 0.12);
  border-radius: 2px;
  outline: none;
}
input[type=range]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 18px;
  height: 18px;
  background: var(--accent-gradient);
  border: 2px solid #fff;
  border-radius: 50%;
  box-shadow: 0 2px 8px rgba(139, 92, 246, 0.3);
  cursor: pointer;
  transition: transform .15s;
}
input[type=range]::-webkit-slider-thumb:hover { transform: scale(1.2); }
input[type=range]::-moz-range-thumb {
  width: 18px;
  height: 18px;
  background: var(--primary-accent);
  border: 2px solid #fff;
  border-radius: 50%;
  box-shadow: 0 2px 8px rgba(139, 92, 246, 0.3);
  cursor: pointer;
}

input[type=color] {
  -webkit-appearance: none;
  -moz-appearance: none;
  appearance: none;
  width: 100%;
  height: 42px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
  padding: 0;
  background-color: rgba(139, 92, 246, 0.03);
  cursor: pointer;
}
input[type=color]::-webkit-color-swatch-wrapper { padding: 4px; }
input[type=color]::-webkit-color-swatch { border-radius: var(--radius-sm); border: none; }

#border-top-input, #border-right-input, #border-bottom-input, #border-left-input,
#custom-ratio-w, #custom-ratio-h {
  display: block;
  width: 100%;
  box-sizing: border-box;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  background-color: rgba(139, 92, 246, 0.03);
  transition: border-color .2s, box-shadow .2s;
  font-size: .875rem;
  padding: .5rem;
  color: var(--text-primary);
  text-align: center;
  font-family: var(--font-mono);
}
#border-top-input:focus, #border-right-input:focus, #border-bottom-input:focus, #border-left-input:focus,
#custom-ratio-w:focus, #custom-ratio-h:focus {
  outline: none;
  border-color: var(--primary-accent);
  box-shadow: 0 0 0 3px rgba(139, 92, 246, 0.1);
}

#watermark-text {
  padding: .5rem .75rem;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  width: 100%;
  font-size: .875rem;
  color: var(--text-primary);
  transition: border-color .2s, box-shadow .2s;
  box-sizing: border-box;
  background-color: rgba(139, 92, 246, 0.03);
}
#watermark-text:focus {
  outline: none;
  border-color: var(--primary-accent);
  box-shadow: 0 0 0 3px rgba(139, 92, 246, 0.1);
}
#watermark-text::placeholder { color: var(--text-muted); }

#watermark-density-btns .action-button { padding: .5rem; display: flex; align-items: center; justify-content: center; }
#watermark-density-btns .action-button.active {
  background: rgba(139, 92, 246, 0.1);
  color: var(--primary-accent);
  border-color: var(--primary-accent);
  font-weight: 600;
}

#quality-selector .action-button.active {
  background: rgba(139, 92, 246, 0.1);
  color: var(--primary-accent);
  border-color: var(--primary-accent);
  font-weight: 600;
}

/* Checkbox */
input[type=checkbox] {
  width: 20px;
  height: 20px;
  border-radius: 4px;
  cursor: pointer;
}

/* ==================== Grid Cells ==================== */
.grid-cell {
  background-color: rgba(139, 92, 246, 0.05);
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
  position: relative;
  overflow: hidden;
  cursor: pointer;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  touch-action: none;
  transition: box-shadow .2s;
}

.grid-cell.drag-over {
  box-shadow: inset 0 0 0 3px var(--primary-accent);
  background-color: rgba(139, 92, 246, 0.1);
}
.grid-cell.selected {
  outline: 3px solid var(--primary-accent);
  outline-offset: -3px;
  box-shadow: 0 0 20px rgba(139, 92, 246, 0.3);
}

.grid-cell.has-image { cursor: grab; }
.grid-cell.has-image.is-panning { cursor: grabbing; }

.cell-button-container {
  position: absolute;
  top: 5px;
  right: 5px;
  display: flex;
  gap: 5px;
  z-index: 10;
}

.cell-icon-btn {
  width: 28px;
  height: 28px;
  background-color: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(8px);
  color: #1a1a2e;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all .2s ease;
  opacity: 0;
  transform: scale(.8);
  pointer-events: none;
  border: none;
  font-size: 18px;
  line-height: 28px;
}
.cell-icon-btn svg { width: 16px; height: 16px; }

.grid-cell.has-image:hover .cell-icon-btn,
.grid-cell.selected .cell-icon-btn { opacity: 1; transform: scale(1); pointer-events: auto; }

.remove-btn:hover { background-color: #ef4444; color: #fff; }
.replace-btn:hover { background-color: var(--primary-accent); color: #fff; transform: scale(1.1) rotate(90deg); }
.zoom-in-btn:hover, .zoom-out-btn:hover { background-color: var(--success); color: #fff; transform: scale(1.2); }
.reset-btn:hover { background-color: #f59e0b; color: #fff; transform: scale(1.1) rotate(360deg); }

.upload-icon-container { display: flex; align-items: center; justify-content: center; width: 100%; height: 100%; }
.upload-icon { width: 36px; height: 36px; color: var(--primary-accent); opacity: .4; transition: opacity .2s; }
.grid-cell:hover .upload-icon { opacity: 0.7; }

/* Image transform inside cell */
.cell-image-wrapper {
  width: 100%;
  height: 100%;
  overflow: hidden;
  position: relative;
}
.cell-image-wrapper img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  pointer-events: none;
  user-select: none;
}

/* ==================== Canvas Hint ==================== */
#canvas-hint {
  position: absolute;
  bottom: 1.5rem;
  left: 50%;
  transform: translate(-50%, 10px);
  background-color: rgba(255, 255, 255, 0.9);
  backdrop-filter: var(--glass-blur);
  color: var(--text-primary);
  padding: .6rem 1.2rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  font-size: .78rem;
  white-space: nowrap;
  opacity: 0;
  transition: opacity .3s ease, transform .3s ease;
  pointer-events: none;
  z-index: 200;
  box-shadow: var(--shadow-md);
}
#canvas-hint.is-visible { opacity: 1; transform: translate(-50%, 0); }
#canvas-hint code {
  background: rgba(139, 92, 246, 0.1);
  color: var(--primary-accent);
  padding: 2px 6px;
  border-radius: 4px;
  font-family: var(--font-mono);
  font-size: .72rem;
}

/* ==================== Sidebar Toggles ==================== */
.pc-sidebar-toggle {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  width: 24px;
  height: 48px;
  background-color: rgba(255, 255, 255, 0.8);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  z-index: 50;
  color: var(--text-muted);
  transition: all .2s ease;
}
.pc-sidebar-toggle:hover {
  background: var(--primary-accent);
  color: #fff;
  border-color: var(--primary-accent);
  box-shadow: var(--accent-glow);
}
#pc-toggle-left { left: calc(var(--sidebar-width) - 2px); border-radius: 0 8px 8px 0; }
#pc-toggle-right { right: calc(var(--sidebar-width) - 2px); border-radius: 8px 0 0 8px; }

#left-sidebar, #right-sidebar, #pc-toggle-left, #pc-toggle-right { transition: all .3s ease-in-out; }

#app-container.left-sidebar-collapsed #left-sidebar { margin-left: calc(-1 * var(--sidebar-width)); }
#app-container.left-sidebar-collapsed #pc-toggle-left { left: -2px; }
#app-container.left-sidebar-collapsed #pc-toggle-left svg { transform: scaleX(-1); }
#app-container.right-sidebar-collapsed #right-sidebar { margin-right: calc(-1 * var(--sidebar-width)); }
#app-container.right-sidebar-collapsed #pc-toggle-right { right: -2px; }
#app-container.right-sidebar-collapsed #pc-toggle-right svg { transform: scaleX(-1); }

/* ==================== Drag Drop Overlay ==================== */
#drag-drop-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 9999;
  display: flex;
  justify-content: center;
  align-items: center;
  background-color: rgba(245, 243, 250, 0.92);
  backdrop-filter: var(--glass-blur);
  transition: opacity .2s ease-in-out;
}
#drag-drop-overlay .drag-drop-content { text-align: center; pointer-events: none; }
#drag-drop-overlay .drag-drop-content svg {
  color: var(--primary-accent);
  margin-bottom: 1rem;
  filter: drop-shadow(0 0 20px rgba(139, 92, 246, 0.3));
}
#drag-drop-overlay .drag-drop-content p {
  font-size: 1.5rem;
  font-weight: 600;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin: 0;
}

/* ==================== Mobile Overlay ==================== */
#mobile-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(26, 26, 46, 0.3);
  backdrop-filter: blur(4px);
  z-index: 999;
  transition: opacity .3s ease;
}
#mobile-overlay.hidden { opacity: 0; pointer-events: none; }
body.sidebar-open { overflow: hidden; }

/* ==================== Text Editor Modal ==================== */
#text-editor-modal {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(26, 26, 46, 0.3);
  backdrop-filter: blur(8px);
  z-index: 10000;
  display: flex;
  justify-content: center;
  align-items: center;
}
#text-editor-modal.hidden { display: none; }
.text-editor-content {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 28px;
  width: 420px;
  max-width: 90vw;
  box-shadow: var(--shadow-md);
}
.text-editor-content h3 {
  margin: 0 0 20px;
  font-size: 1.1rem;
  color: var(--text-primary);
  font-weight: 700;
}
#text-editor-input {
  width: 100%;
  min-height: 80px;
  padding: 12px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-family: inherit;
  resize: vertical;
  box-sizing: border-box;
  margin-bottom: 16px;
  background-color: rgba(139, 92, 246, 0.03);
  color: var(--text-primary);
}
#text-editor-input:focus {
  outline: none;
  border-color: var(--primary-accent);
  box-shadow: 0 0 0 3px rgba(139, 92, 246, 0.1);
}
#text-editor-input::placeholder { color: var(--text-muted); }
.text-editor-controls { display: flex; gap: 16px; margin-bottom: 16px; flex-wrap: wrap; }
.text-editor-controls label { display: flex; align-items: center; gap: 8px; font-size: .85rem; color: var(--text-secondary); }
.text-editor-controls input[type=number] {
  width: 60px;
  padding: 4px 8px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  background-color: rgba(139, 92, 246, 0.03);
  color: var(--text-primary);
}
.text-editor-controls input[type=color] { width: 40px; height: 32px; }
.text-editor-buttons { display: flex; justify-content: flex-end; gap: 12px; }

/* ==================== Annotation Elements ==================== */
.text-element-container {
  position: absolute;
  transform: translate(-50%, -50%);
  padding: 10px;
  border: 2px dashed transparent;
  transition: border-color .2s ease;
}
.text-element-container:hover { border-color: rgba(139, 92, 246, .4); }
.text-element-container.selected { border-color: var(--primary-accent); z-index: 10; }
.text-content {
  cursor: move;
  padding: 8px 12px;
  white-space: pre-wrap;
  outline: none;
  font-weight: 700;
  text-shadow: 1px 1px 2px rgba(0, 0, 0, .5);
  user-select: none;
}
.text-content:focus { cursor: text; }

.text-element-container .delete-text-button {
  display: none;
  position: absolute;
  top: -10px;
  right: -10px;
  width: 24px;
  height: 24px;
  background: var(--danger);
  color: #fff;
  border: 2px solid #fff;
  border-radius: 50%;
  cursor: pointer;
  font-family: sans-serif;
  font-weight: 700;
  align-items: center;
  justify-content: center;
  line-height: 1;
  z-index: 20;
  font-size: 14px;
}
.text-element-container.selected .delete-text-button { display: flex; }

.arrow-container {
  position: absolute;
  cursor: move;
  z-index: 5;
}
.arrow-container.selected { z-index: 15; }
.arrow-container svg { width: 100%; height: 100%; overflow: visible; }
.arrow-container .delete-text-button { display: none; }
.arrow-container.selected .delete-text-button { display: flex; }

.shape-container {
  position: absolute;
  border: 1px dashed transparent;
  transition: border-color .2s;
  z-index: 5;
}
.shape-container.selected { border-color: var(--primary-accent); z-index: 15; }
.shape-element { width: 100%; height: 100%; cursor: move; }
.shape-container .delete-text-button { display: none; }
.shape-container.selected .delete-text-button { display: flex; }

.resize-handle {
  display: none;
  position: absolute;
  width: 10px;
  height: 10px;
  background-color: #fff;
  border: 2px solid var(--primary-accent);
  border-radius: 50%;
  transform: translate(-50%, -50%);
  z-index: 25;
}
.shape-container.selected .resize-handle { display: block; }
.resize-handle.se { bottom: 0; right: 0; transform: translate(50%, 50%); cursor: nwse-resize; }
.resize-handle.sw { bottom: 0; left: 0; transform: translate(-50%, 50%); cursor: nesw-resize; }
.resize-handle.ne { top: 0; right: 0; transform: translate(50%, -50%); cursor: nesw-resize; }
.resize-handle.nw { top: 0; left: 0; cursor: nwse-resize; }

/* ==================== Responsive ==================== */
@media (max-width: 1024px) {
  .pc-sidebar-toggle { display: none; }
  #app-nav { padding: 0 16px; }
  .nav-title {
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    font-size: 1.1rem;
    max-width: calc(100% - 140px);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
  }
  .nav-title svg { width: 24px; height: 24px; }
  .nav-links { display: none; }
  .mobile-nav-btn { display: block; }
  #center-content { padding: 1rem; }
  #left-sidebar, #right-sidebar {
    width: 280px;
    height: 100%;
    position: fixed;
    top: 0;
    left: 0;
    z-index: 1000;
    border: none;
    padding-top: var(--nav-height);
    box-shadow: var(--shadow-md);
    transform: translate(-100%);
    transition: transform .3s ease-in-out;
  }
  #right-sidebar { left: auto; right: 0; transform: translate(100%); }
  #left-sidebar.is-open, #right-sidebar.is-open { transform: translate(0); }
  #canvas-action-toolbar { justify-content: center; flex-wrap: wrap; }
  .toolbar-group-right { margin-left: 0; }
  #canvas-action-toolbar .action-button span { display: none; }
  #canvas-action-toolbar .action-button { padding: 10px; justify-content: center; gap: 0; }
  #canvas-hint { display: none; }
  .dropdown-menu {
    position: fixed !important;
    top: var(--nav-height) !important;
    right: 0 !important;
    left: auto !important;
    width: min(300px, 90vw) !important;
    max-height: calc(100vh - var(--nav-height)) !important;
    overflow-y: auto !important;
    border-radius: var(--radius-md) !important;
  }
  .bg-glow { display: none; }
}