/* ========== CSS Variables & Theme ========== */
:root {
  --bg-primary: #f0f2f5;
  --bg-secondary: #ffffff;
  --bg-panel: #ffffff;
  --text-primary: #1a1a2e;
  --text-secondary: #555;
  --border-color: #e0e0e0;
  --accent: #4361ee;
  --accent-hover: #3a56d4;
  --accent-light: #eef0ff;
  --grid-line: #4361ee;
  --cell-hover: rgba(67, 97, 238, 0.15);
  --cell-selected: rgba(67, 97, 238, 0.3);
  --shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 4px 24px rgba(0, 0, 0, 0.12);
  --radius: 8px;
  --radius-sm: 4px;
  --transition: 0.2s ease;
  --item-colors: #4361ee, #f72585, #4cc9f0, #7209b7, #3a0ca3, #560bad,
    #480ca8, #b5179e, #f15bb5, #fee440, #00bbf9, #00f5d4;
  --header-bg: #ffffff;
  --code-bg: #1e1e2e;
  --code-text: #cdd6f4;
  --toast-bg: #323232;
  --toast-text: #fff;
  --footer-bg: #f5f5f5;
}

[data-theme="dark"] {
  --bg-primary: #1a1a2e;
  --bg-secondary: #16213e;
  --bg-panel: #1e2746;
  --text-primary: #e8e8e8;
  --text-secondary: #a0a0b0;
  --border-color: #2a2a4a;
  --accent: #6b83ff;
  --accent-hover: #5a70e8;
  --accent-light: #1e2746;
  --cell-hover: rgba(107, 131, 255, 0.2);
  --cell-selected: rgba(107, 131, 255, 0.35);
  --shadow: 0 2px 12px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 4px 24px rgba(0, 0, 0, 0.4);
  --header-bg: #16213e;
  --code-bg: #11111b;
  --code-text: #cdd6f4;
  --toast-bg: #45475a;
  --toast-text: #fff;
  --footer-bg: #16213e;
}

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

html {
  font-size: 14px;
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial,
    sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  transition: background var(--transition), color var(--transition);
}

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

/* ========== Header ========== */
.app-header {
  background: var(--header-bg);
  border-bottom: 1px solid var(--border-color);
  padding: 0.75rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  box-shadow: var(--shadow);
  position: sticky;
  top: 0;
  z-index: 100;
  transition: background var(--transition);
}

.header-left {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
}

.header-left h1 {
  font-size: 1.25rem;
  font-weight: 700;
  white-space: nowrap;
}

.subtitle {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.header-right {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.responsive-toggle {
  display: flex;
  gap: 2px;
  background: var(--bg-primary);
  border-radius: var(--radius);
  padding: 2px;
}

.resp-btn {
  padding: 0.4rem 0.75rem;
  border: none;
  background: transparent;
  border-radius: calc(var(--radius) - 2px);
  cursor: pointer;
  font-size: 0.8rem;
  color: var(--text-secondary);
  transition: all var(--transition);
  white-space: nowrap;
}

.resp-btn:hover {
  color: var(--text-primary);
}

.resp-btn.active {
  background: var(--accent);
  color: #fff;
  box-shadow: 0 2px 4px rgba(67, 97, 238, 0.3);
}

.theme-btn {
  width: 36px;
  height: 36px;
  border: 1px solid var(--border-color);
  border-radius: 50%;
  background: var(--bg-secondary);
  cursor: pointer;
  font-size: 1.1rem;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition);
}

.theme-btn:hover {
  transform: rotate(30deg);
  border-color: var(--accent);
}

/* ========== Main Layout ========== */
.app-main {
  flex: 1;
  display: grid;
  grid-template-columns: 260px 1fr 300px;
  gap: 0;
  overflow: hidden;
  height: calc(100vh - 110px);
}

/* ========== Sidebar ========== */
.sidebar {
  background: var(--bg-secondary);
  border-right: 1px solid var(--border-color);
  overflow-y: auto;
  padding: 0.75rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  transition: background var(--transition);
}

.sidebar-right {
  border-right: none;
  border-left: 1px solid var(--border-color);
}

.panel {
  background: var(--bg-panel);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 0.75rem;
  box-shadow: var(--shadow);
  transition: background var(--transition);
}

.panel-title {
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border-color);
}

.sub-title {
  font-size: 0.85rem;
  font-weight: 600;
  margin: 0.75rem 0 0.5rem;
  color: var(--text-secondary);
}

/* ========== Controls ========== */
.control-group {
  margin-bottom: 0.6rem;
}

.control-group label {
  display: block;
  font-size: 0.8rem;
  color: var(--text-secondary);
  margin-bottom: 0.25rem;
  font-weight: 500;
}

.input-row {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

input[type="range"] {
  flex: 1;
  height: 4px;
  -webkit-appearance: none;
  appearance: none;
  background: var(--border-color);
  border-radius: 2px;
  outline: none;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--accent);
  cursor: pointer;
  box-shadow: 0 1px 4px rgba(67, 97, 238, 0.4);
}

.num-input,
.text-input {
  width: 56px;
  padding: 0.3rem 0.4rem;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  background: var(--bg-primary);
  color: var(--text-primary);
  font-size: 0.8rem;
  text-align: center;
  outline: none;
  transition: border-color var(--transition);
}

.num-input:focus,
.text-input:focus {
  border-color: var(--accent);
}

.text-input {
  width: 100%;
  text-align: left;
}

.unit {
  font-size: 0.75rem;
  color: var(--text-secondary);
}

select {
  width: 100%;
  padding: 0.35rem 0.5rem;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  background: var(--bg-primary);
  color: var(--text-primary);
  font-size: 0.8rem;
  cursor: pointer;
  outline: none;
  transition: border-color var(--transition);
}

select:focus {
  border-color: var(--accent);
}

.hidden {
  display: none !important;
}

/* ========== Presets ========== */
.presets-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.4rem;
}

.preset-btn {
  padding: 0.45rem 0.5rem;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  background: var(--bg-primary);
  color: var(--text-primary);
  font-size: 0.78rem;
  cursor: pointer;
  transition: all var(--transition);
  text-align: center;
}

.preset-btn:hover {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}

/* ========== Editor Area ========== */
.editor-area {
  display: flex;
  flex-direction: column;
  overflow: hidden;
  padding: 0.75rem;
  background: var(--bg-primary);
}

.editor-toolbar {
  margin-bottom: 0.5rem;
}

.editor-toolbar h2 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.15rem;
}

.editor-hint {
  font-size: 0.78rem;
  color: var(--text-secondary);
}

.viewport-frame {
  flex: 1;
  border: 2px solid var(--border-color);
  border-radius: var(--radius);
  background: var(--bg-secondary);
  overflow: auto;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding: 1.5rem;
  transition: max-width var(--transition), border-color var(--transition);
  margin: 0 auto;
  width: 100%;
}

.viewport-desktop {
  max-width: 100%;
}

.viewport-tablet {
  max-width: 768px;
}

.viewport-mobile {
  max-width: 375px;
}

/* ========== Grid Container ========== */
.grid-container {
  width: 100%;
  min-height: 400px;
  border: 2px dashed var(--border-color);
  border-radius: var(--radius);
  padding: 8px;
  position: relative;
  display: grid;
  transition: all var(--transition);
}

.grid-cell {
  border: 1px dashed var(--grid-line);
  border-radius: var(--radius-sm);
  min-height: 60px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  color: var(--text-secondary);
  cursor: pointer;
  transition: background var(--transition);
  position: relative;
  user-select: none;
}

.grid-cell:hover {
  background: var(--cell-hover);
}

.grid-cell.in-selection {
  background: var(--cell-selected);
}

.grid-cell.dragging {
  background: var(--cell-selected);
  border-color: var(--accent);
}

/* ========== Grid Items ========== */
.grid-item {
  border-radius: var(--radius-sm);
  padding: 0.4rem 0.6rem;
  font-size: 0.8rem;
  font-weight: 600;
  color: #fff;
  cursor: move;
  display: flex;
  align-items: center;
  justify-content: center;
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.3);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  min-height: 60px;
  transition: opacity var(--transition);
  position: relative;
  z-index: 2;
}

.grid-item .item-label {
  pointer-events: none;
}

/* ========== Items Panel ========== */
.items-header {
  display: flex;
  gap: 0.4rem;
  margin-bottom: 0.5rem;
}

.action-btn {
  flex: 1;
  padding: 0.45rem 0.5rem;
  border: 1px solid var(--accent);
  border-radius: var(--radius-sm);
  background: var(--accent);
  color: #fff;
  font-size: 0.78rem;
  cursor: pointer;
  transition: all var(--transition);
  text-align: center;
}

.action-btn:hover {
  background: var(--accent-hover);
}

.action-btn.secondary {
  background: transparent;
  color: var(--text-secondary);
  border-color: var(--border-color);
}

.action-btn.secondary:hover {
  border-color: #e74c3c;
  color: #e74c3c;
  background: rgba(231, 76, 60, 0.08);
}

.items-list {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  max-height: 300px;
  overflow-y: auto;
}

.item-card {
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 0.5rem;
  font-size: 0.78rem;
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  transition: border-color var(--transition);
}

.item-card:hover {
  border-color: var(--accent);
}

.item-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.item-color-dot {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  display: inline-block;
  margin-right: 0.3rem;
  vertical-align: middle;
}

.item-name-input {
  width: 80px;
  padding: 0.2rem 0.3rem;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  background: var(--bg-secondary);
  color: var(--text-primary);
  font-size: 0.75rem;
  outline: none;
}

.item-name-input:focus {
  border-color: var(--accent);
}

.item-card-row {
  display: flex;
  align-items: center;
  gap: 0.3rem;
  font-size: 0.72rem;
  color: var(--text-secondary);
}

.item-card-row span {
  white-space: nowrap;
}

.item-card-row select,
.item-card-row input {
  font-size: 0.72rem;
  padding: 0.15rem 0.25rem;
}

.item-card-row select {
  flex: 1;
}

.item-card-row input {
  width: 36px;
}

.item-delete-btn {
  background: none;
  border: none;
  cursor: pointer;
  font-size: 0.85rem;
  padding: 0 0.2rem;
  color: var(--text-secondary);
  transition: color var(--transition);
}

.item-delete-btn:hover {
  color: #e74c3c;
}

.items-count {
  font-size: 0.75rem;
  color: var(--text-secondary);
  margin-top: 0.5rem;
  text-align: right;
}

/* ========== Code Output ========== */
.code-tabs {
  display: flex;
  gap: 2px;
  background: var(--bg-primary);
  border-radius: var(--radius-sm);
  padding: 2px;
  margin-bottom: 0.5rem;
}

.code-tab {
  flex: 1;
  padding: 0.35rem;
  border: none;
  background: transparent;
  border-radius: calc(var(--radius-sm) - 1px);
  cursor: pointer;
  font-size: 0.78rem;
  color: var(--text-secondary);
  transition: all var(--transition);
}

.code-tab:hover {
  color: var(--text-primary);
}

.code-tab.active {
  background: var(--accent);
  color: #fff;
}

.code-output {
  background: var(--code-bg);
  border-radius: var(--radius-sm);
  padding: 0.75rem;
  max-height: 350px;
  overflow: auto;
}

.code-output pre {
  margin: 0;
  white-space: pre-wrap;
  word-break: break-word;
}

.code-output code {
  font-family: "JetBrains Mono", "Fira Code", "Cascadia Code", Consolas,
    monospace;
  font-size: 0.72rem;
  line-height: 1.5;
  color: var(--code-text);
}

.copy-btn {
  margin-top: 0.5rem;
  width: 100%;
  background: transparent;
  color: var(--accent);
  border-color: var(--accent);
}

.copy-btn:hover {
  background: var(--accent);
  color: #fff;
}

/* ========== Toast ========== */
.toast {
  position: fixed;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  background: var(--toast-bg);
  color: var(--toast-text);
  padding: 0.6rem 1.5rem;
  border-radius: var(--radius);
  font-size: 0.85rem;
  box-shadow: var(--shadow-lg);
  z-index: 1000;
  opacity: 0;
  transition: all 0.3s ease;
  pointer-events: none;
}

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

/* ========== Footer ========== */
.app-footer {
  background: var(--footer-bg);
  border-top: 1px solid var(--border-color);
  padding: 0.5rem 1.5rem;
  text-align: center;
  font-size: 0.75rem;
  color: var(--text-secondary);
  transition: background var(--transition);
}

/* ========== Scrollbar ========== */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-secondary);
}

/* ========== Responsive ========== */
@media (max-width: 1100px) {
  .app-main {
    grid-template-columns: 1fr;
    height: auto;
  }

  .sidebar {
    border-right: none;
    border-bottom: 1px solid var(--border-color);
  }

  .sidebar-right {
    border-left: none;
    border-top: 1px solid var(--border-color);
  }

  .editor-area {
    min-height: 400px;
  }
}

@media (max-width: 600px) {
  .app-header {
    flex-direction: column;
    gap: 0.5rem;
    padding: 0.5rem;
  }

  .header-left h1 {
    font-size: 1rem;
  }

  .resp-btn {
    font-size: 0.72rem;
    padding: 0.3rem 0.5rem;
  }
}