/* ═══════════════════════════════════════════════════════════
   DiagramKit
   依赖：assets/fonts/fonts.css + assets/base.css
═══════════════════════════════════════════════════════════ */

:root {
  --app-font: var(--font-heading-cn);
  --app-font-display: var(--font-display-cn);
  --app-font-body: var(--font-body-cn);
  --app-font-mono: "JetBrains Mono", "SF Mono", Consolas, monospace;

  --app-ink: var(--color-text-primary);
  --app-ink-2: var(--color-text-secondary);
  --app-ink-3: var(--color-text-muted);

  --app-bg: var(--color-bg-base);
  --app-bg-raised: var(--color-bg-raised);
  --app-bg-overlay: var(--color-bg-overlay);

  --app-border: var(--color-border-subtle);
  --app-border-strong: var(--color-border-default);

  --app-accent: var(--color-accent-orange);
  --app-accent-warm: var(--color-accent-warm);
}

/* ═══════════════════════════════════════
   图表类型切换导航栏
═══════════════════════════════════════ */
.diagram-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 10000;
  background: color-mix(in srgb, var(--app-bg-overlay) 95%, transparent);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--app-border);
  box-shadow: 0 2px 8px rgba(20, 20, 19, 0.04);
}

.diagram-nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 20px;
  height: 52px;
  gap: 16px;
}

.diagram-nav-home {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--app-ink);
  font-weight: 500;
  font-size: 0.9rem;
  flex-shrink: 0;
  transition: color var(--duration-fast) var(--ease-default);
}

.diagram-nav-home:hover {
  color: var(--app-accent);
}

.diagram-nav-home svg {
  width: 18px;
  height: 18px;
}

.nav-home-label {
  font-family: var(--app-font);
}

.diagram-nav-tabs {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 4px;
  flex: 1;
  min-width: 0;
}

.diagram-nav-tab {
  padding: 8px 16px;
  color: var(--app-ink-2);
  font-size: 0.85rem;
  font-weight: 500;
  border-radius: 6px;
  transition:
    color var(--duration-fast) var(--ease-default),
    background var(--duration-fast) var(--ease-default);
}

.diagram-nav-tab:hover {
  color: var(--app-ink);
  background: color-mix(in srgb, var(--app-bg-overlay) 50%, transparent);
}

.diagram-nav-tab.active {
  color: var(--app-accent);
  background: color-mix(in srgb, var(--app-accent) 12%, transparent);
}

.diagram-nav-actions {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
}

/* 导航栏内的图标按钮样式（参考首页 .icon-btn）*/
.nav-icon-btn.icon-btn {
  width: 36px;
  height: 36px;
  border-radius: 999px;
  border: 1px solid var(--app-border-strong);
  color: var(--app-ink-2);
  background: transparent;
  display: grid;
  place-items: center;
  transition:
    color var(--duration-fast) var(--ease-default),
    border-color var(--duration-fast) var(--ease-default),
    background var(--duration-fast) var(--ease-default);
}

.nav-icon-btn.icon-btn:hover {
  color: var(--app-ink);
  border-color: var(--app-accent);
  background: var(--app-bg-raised);
}

.nav-icon-btn.icon-btn svg {
  width: 16px;
  height: 16px;
}

.nav-icon-btn.icon-btn:focus-visible {
  outline: 2px solid var(--app-accent);
  outline-offset: 2px;
}

@media (max-width: 900px) {
  .diagram-nav-inner {
    padding: 0 12px;
  }

  .diagram-nav-tabs {
    gap: 2px;
    overflow-x: auto;
    scrollbar-width: none;
  }

  .diagram-nav-tabs::-webkit-scrollbar {
    display: none;
  }

  .diagram-nav-tab {
    padding: 6px 10px;
    font-size: 0.78rem;
    white-space: nowrap;
  }

  .nav-home-label {
    display: none;
  }
}

@media (max-width: 500px) {
  .diagram-nav-inner {
    height: 44px;
  }

  .diagram-nav-tab {
    padding: 5px 8px;
    font-size: 0.72rem;
  }

  .nav-icon-btn.icon-btn {
    width: 30px;
    height: 30px;
  }

  .nav-icon-btn.icon-btn svg {
    width: 14px;
    height: 14px;
  }
}

/* 历史面板打开时隐藏导航栏 */
body.history-open .diagram-nav {
  opacity: 0;
  pointer-events: none;
}

/* 页面内容下移，避免被导航栏遮挡 */
.app-container {
  margin-top: 52px;
}

@media (max-width: 500px) {
  .app-container {
    margin-top: 44px;
  }
}

/* ═══════════════════════════════════════
   "正在开发中" 占位页面
═══════════════════════════════════════ */
.coming-soon {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 400px;
  padding: 60px 20px;
  text-align: center;
}

.coming-soon-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 24px;
  color: var(--app-accent);
}

.coming-soon h2 {
  font-family: var(--app-font);
  font-size: 1.8rem;
  font-weight: 600;
  color: var(--app-ink);
  margin-bottom: 16px;
}

.coming-soon p {
  font-size: 1rem;
  color: var(--app-ink-2);
  margin-bottom: 32px;
  max-width: 400px;
}

.coming-soon .btn {
  width: auto;
  min-width: 160px;
}

* {
  outline: none;
}

body {
  background-color: var(--app-bg);
  color: var(--app-ink);
  font-family: var(--app-font);
  font-size: var(--text-base);
  line-height: var(--leading-cn-normal);
  min-height: 100vh;
  margin: 0;
  padding: 0;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  position: relative;
}

/* 单一暖色晕染 + 角落冷色点缀，极克制 */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background:
    radial-gradient(
      ellipse 60% 50% at 12% 0%,
      rgba(217, 119, 87, 0.09) 0%,
      transparent 60%
    ),
    radial-gradient(
      ellipse 45% 45% at 100% 100%,
      rgba(106, 155, 204, 0.06) 0%,
      transparent 55%
    );
}

::selection {
  background: var(--app-accent);
  color: #fff;
}

.app-container {
  max-width: 1600px;
  margin: 0 auto;
  padding: clamp(32px, 4vw, 64px) clamp(12px, 1.5vw, 20px) clamp(32px, 4vw, 48px);
}

/* ═══════════════════════════════════════
   头部
═══════════════════════════════════════ */
.header {
  margin: 0 auto clamp(28px, 3.6vw, 48px);
  max-width: 860px;
  text-align: center;
  animation: fadeInDown 0.9s var(--ease-default);
}

.header-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--app-font);
  font-size: var(--text-xs);
  font-weight: var(--weight-medium);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--app-ink-2);
  margin-bottom: var(--space-4);
}

.header-eyebrow::before,
.header-eyebrow::after {
  content: "";
  width: 28px;
  height: 1px;
  background: var(--app-border-strong);
}

.header h1 {
  font-family: var(--app-font-display);
  font-weight: var(--weight-regular);
  font-size: clamp(2rem, 4.4vw, 3.4rem);
  line-height: var(--leading-cn-tight);
  letter-spacing: -0.015em;
  color: var(--app-ink);
  margin: 0 0 var(--space-4) 0;
}

.header h1 em {
  font-style: normal;
  color: var(--app-accent-warm);
  font-weight: var(--weight-regular);
}

.header p {
  font-family: var(--app-font-body);
  font-size: clamp(1rem, 1.15vw, 1.12rem);
  color: var(--app-ink-2);
  line-height: var(--leading-cn-loose);
  margin: 0 auto;
  max-width: 48em;
}

.header-hint {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  font-family: var(--app-font) !important;
  font-size: var(--text-xs) !important;
  font-weight: var(--weight-medium);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--app-ink-3) !important;
  margin: var(--space-5) auto 0 !important;
  line-height: 1 !important;
}

.header-hint-row {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  /* 不主动断行 —— 否则英文那行被 .header(max-width:860px) 收窄后会被
     拆成两段；溢出由 align-items:center 自然两侧扩展 */
  white-space: nowrap;
}

/* 装饰短横线只挂在第一行的左右两端 */
.header-hint-row:first-child::before,
.header-hint-row:first-child::after {
  content: "";
  width: 22px;
  height: 1px;
  background: var(--app-border-strong);
}

.header-hint-row--secondary {
  color: var(--app-ink-3);
  opacity: 0.85;
}

/* ═══════════════════════════════════════
   主布局
═══════════════════════════════════════ */
.main-content {
  display: grid;
  grid-template-columns: 440px 1fr;
  gap: clamp(20px, 2.4vw, 32px);
  align-items: stretch;
  animation: fadeInUp 0.9s var(--ease-default) 0.15s backwards;
}

/* ═══════════════════════════════════════
   卡片
═══════════════════════════════════════ */
.card {
  background: var(--app-bg-raised);
  border: 1px solid var(--app-border);
  border-radius: var(--radius-xl);
  box-shadow: 0 2px 12px rgba(20, 20, 19, 0.05);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  height: 100%;
  transition:
    border-color var(--duration-normal) var(--ease-default),
    box-shadow var(--duration-normal) var(--ease-default);
}

.card:hover {
  border-color: var(--app-border-strong);
  box-shadow: 0 8px 28px rgba(20, 20, 19, 0.07);
}

.card-header {
  padding: 18px 24px;
  border-bottom: 1px solid var(--app-border);
  background: var(--app-bg-overlay);
  display: flex;
  justify-content: space-between;
  align-items: center;
  min-height: 66px;
}

.card-title {
  font-family: var(--app-font-display);
  font-weight: var(--weight-medium);
  font-size: 1.18rem;
  color: var(--app-ink);
  letter-spacing: -0.01em;
  margin: 0;
  display: flex;
  align-items: center;
  gap: 10px;
}

.card-title span {
  font-size: 1.2rem;
}

.card-content {
  padding: 24px;
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.inline-label {
  font-family: var(--app-font);
  font-size: var(--text-sm);
  color: var(--app-ink-2);
  letter-spacing: 0.01em;
}

/* ═══════════════════════════════════════
   输入框（textarea fallback）
═══════════════════════════════════════ */
.input-textarea {
  width: 100%;
  min-height: 480px;
  border: 1px solid var(--app-border);
  border-radius: var(--radius-md);
  padding: 18px;
  font-family: var(--app-font-mono);
  font-size: 13.5px;
  line-height: 1.65;
  background: var(--app-bg-overlay);
  color: var(--app-ink);
  resize: none;
  flex: 1;
  transition:
    border-color var(--duration-normal) var(--ease-default),
    box-shadow var(--duration-normal) var(--ease-default);
}

.input-textarea:focus {
  border-color: var(--app-accent);
  box-shadow: 0 0 0 3px rgba(217, 119, 87, 0.2);
}

/* ═══════════════════════════════════════
   按钮
═══════════════════════════════════════ */
.btn {
  height: 46px;
  padding: 0 18px;
  border: 1px solid transparent;
  border-radius: var(--radius-full);
  font-family: var(--app-font);
  font-size: 0.92rem;
  font-weight: var(--weight-medium);
  letter-spacing: 0.01em;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  width: 100%;
  white-space: nowrap;
  transition:
    transform var(--duration-fast) var(--ease-default),
    background var(--duration-normal) var(--ease-default),
    color var(--duration-normal) var(--ease-default),
    border-color var(--duration-normal) var(--ease-default),
    box-shadow var(--duration-normal) var(--ease-default);
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none !important;
  box-shadow: none !important;
}

.btn-primary {
  background: var(--app-accent);
  color: #fff;
  box-shadow: 0 6px 18px rgba(217, 119, 87, 0.3);
}

.btn-primary:hover {
  transform: translateY(-2px);
  background: var(--app-accent-warm);
  box-shadow: 0 10px 26px rgba(201, 100, 66, 0.38);
}

.btn-primary:active {
  transform: translateY(0);
}

.btn-secondary {
  background: transparent;
  color: var(--app-ink);
  border-color: var(--app-border-strong);
}

.btn-secondary:hover {
  transform: translateY(-2px);
  background: var(--app-bg-overlay);
  border-color: var(--app-ink);
}

.btn-secondary:active {
  transform: translateY(0);
  background: var(--app-bg-raised);
}

.btn-sm {
  height: 36px;
  padding: 0 16px;
  font-size: 0.82rem;
  width: auto;
}

.btn-accent {
  background: rgba(217, 119, 87, 0.08);
  color: var(--app-accent-warm);
  border: 1px solid rgba(217, 119, 87, 0.22);
}

.btn-accent:hover {
  background: rgba(217, 119, 87, 0.14);
  border-color: rgba(217, 119, 87, 0.38);
  transform: translateY(-1px);
}

.btn-accent:active {
  transform: translateY(0);
  background: rgba(217, 119, 87, 0.18);
}

.button-group {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  margin-top: auto;
}

.button-group .btn-primary {
  flex: 1 1 0;
  width: auto;
  min-width: 0;
  overflow: hidden;
}

.button-group .btn-secondary {
  flex: 1;
  min-width: 140px;
}

/* 主按钮标签在导出按钮展开时平滑收缩为短标签；
   切换动效与导出按钮的 .export-view 完全一致（同一组 transition） */
.btn-primary-label-stack {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  line-height: 1;
  pointer-events: none;
  white-space: nowrap;
}
.btn-primary-label-stack .label-long,
.btn-primary-label-stack .label-short {
  transition:
    opacity 240ms ease,
    transform 340ms cubic-bezier(0.32, 0.72, 0, 1);
  will-change: opacity, transform;
}
.btn-primary-label-stack .label-short {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
}
/* 默认：长标签在位，短标签下移并透明 */
.btn-primary-label-stack .label-long {
  opacity: 1;
  transform: translateY(0);
}
.btn-primary-label-stack .label-short {
  opacity: 0;
  transform: translateY(6px);
}
/* compact：长标签下移并透明，短标签归位 */
.btn-primary-label-stack[data-compact="true"] .label-long {
  opacity: 0;
  transform: translateY(6px);
}
.btn-primary-label-stack[data-compact="true"] .label-short {
  opacity: 1;
  transform: translateY(0);
}

/* ═══════════════════════════════════════
   ER 图示容器
═══════════════════════════════════════ */
.diagram-container {
  width: 100%;
  flex: 1;
  min-height: 600px;
  background-color: #ffffff;
  background-image: radial-gradient(
    rgba(20, 20, 19, 0.14) 1.5px,
    transparent 1.5px
  );
  background-size: 24px 24px;
  border: none;
  border-radius: 0;
  position: relative;
  overflow: hidden;
  box-shadow: inset 0 1px 0 rgba(20, 20, 19, 0.02);
  transition: background-image var(--duration-normal) var(--ease-default);
}

.diagram-container.no-grid {
  background-image: none;
  background-color: #ffffff;
}

/* ═══════════════════════════════════════
   浮动按钮
═══════════════════════════════════════ */
.background-toggle,
.colorize-toggle,
.attrs-toggle,
.history-toggle {
  position: absolute;
  left: 16px;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: 1px solid var(--app-border);
  background: color-mix(in srgb, var(--app-bg-overlay) 92%, transparent);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  box-shadow: 0 2px 8px rgba(20, 20, 19, 0.06);
  display: grid;
  place-items: center;
  cursor: pointer;
  z-index: 100;
  transition:
    transform var(--duration-fast) var(--ease-default),
    background var(--duration-normal) var(--ease-default),
    border-color var(--duration-normal) var(--ease-default),
    box-shadow var(--duration-normal) var(--ease-default);
}

.background-toggle {
  top: 16px;
}

.colorize-toggle {
  top: 64px;
}

.attrs-toggle {
  top: 112px;
}

.history-toggle {
  top: 160px;
}

.background-toggle:hover,
.colorize-toggle:hover,
.attrs-toggle:hover,
.history-toggle:hover {
  transform: scale(1.06);
  border-color: var(--app-accent);
  box-shadow: 0 6px 16px rgba(20, 20, 19, 0.1);
}

.background-toggle:active,
.colorize-toggle:active,
.attrs-toggle:active,
.history-toggle:active {
  transform: scale(0.95);
}

.background-toggle > svg,
.colorize-toggle > svg,
.attrs-toggle > svg,
.history-toggle > svg {
  font-size: 16px;
  color: var(--app-ink-2);
  display: block;
  transition: color var(--duration-fast) var(--ease-default);
}

.background-toggle:hover > svg,
.colorize-toggle:hover > svg,
.attrs-toggle:hover > svg,
.history-toggle:hover > svg {
  color: var(--app-accent-warm);
}

.colorize-toggle.active {
  background: linear-gradient(135deg, #dbeafe 0%, #f3e8ff 50%, #ffe4e6 100%);
  border-color: rgba(14, 165, 233, 0.3);
  box-shadow: 0 4px 14px rgba(139, 92, 246, 0.18);
}

.colorize-toggle.active > svg {
  color: #0ea5e9;
}

.colorize-toggle.active:hover {
  background: linear-gradient(135deg, #bfdbfe 0%, #e9d5ff 50%, #fecdd3 100%);
  border-color: rgba(14, 165, 233, 0.45);
}

.colorize-toggle.active:hover > svg {
  color: #0284c7;
}

.attrs-toggle,
.colorize-toggle {
  overflow: hidden;
}

.attrs-toggle::after,
.colorize-toggle::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 50%;
  width: 28px;
  height: 2px;
  background: var(--app-ink-2);
  border-radius: 2px;
  transform: translate(-50%, -50%) rotate(-45deg) scaleX(0);
  transform-origin: center;
  transition:
    transform var(--duration-normal) var(--ease-default),
    background var(--duration-fast) var(--ease-default);
  pointer-events: none;
}

.attrs-toggle.active::after {
  transform: translate(-50%, -50%) rotate(-45deg) scaleX(1);
}

.colorize-toggle:not(.active)::after {
  transform: translate(-50%, -50%) rotate(-45deg) scaleX(1);
}

.attrs-toggle:hover::after,
.colorize-toggle:hover::after {
  background: var(--app-accent-warm);
}

/* ═══════════════════════════════════════
   加载与错误
═══════════════════════════════════════ */
.loading-overlay {
  position: absolute;
  inset: 0;
  background: color-mix(in srgb, var(--app-bg-overlay) 78%, transparent);
  display: grid;
  place-items: center;
  z-index: 10;
  -webkit-backdrop-filter: blur(4px);
  backdrop-filter: blur(4px);
}

.spinner {
  width: 44px;
  height: 44px;
  border: 3px solid rgba(217, 119, 87, 0.18);
  border-top-color: var(--app-accent);
  border-radius: 50%;
  animation: spin 1s var(--ease-gentle) infinite;
}

.error-message {
  background: rgba(192, 69, 58, 0.08);
  color: var(--color-error);
  padding: 14px 18px;
  border-radius: var(--radius-md);
  border: 1px solid rgba(192, 69, 58, 0.22);
  font-size: 0.95rem;
  display: flex;
  align-items: center;
  gap: 10px;
}

/* ═══════════════════════════════════════
   图例
═══════════════════════════════════════ */
.legend-item {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  background: var(--app-bg-overlay);
  border: 1px solid var(--app-border);
  border-radius: 999px;
  font-family: var(--app-font);
  font-size: 0.78rem;
  color: var(--app-ink-2);
  transition:
    color var(--duration-fast) var(--ease-default),
    border-color var(--duration-fast) var(--ease-default);
}

.legend-item:hover {
  color: var(--app-ink);
  border-color: var(--app-border-strong);
}

/* ═══════════════════════════════════════
   CodeMirror 6
   宿主 div 用 .cm-host 提供盒模型；CM6 自身渲染
   `.cm-editor` / `.cm-content` / `.cm-gutters` 等。
═══════════════════════════════════════ */
.cm-host {
  height: 480px;
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: 0 0 0 1px var(--app-border);
  transition: box-shadow var(--duration-normal) var(--ease-default);
  background: var(--app-bg-overlay);
}

.cm-host:focus-within {
  box-shadow:
    0 0 0 1.5px var(--app-accent),
    0 0 0 4.5px rgba(217, 119, 87, 0.22);
}

.cm-host .cm-editor {
  height: 100%;
  font-family: var(--app-font-mono);
  font-size: 13.5px;
  background: transparent;
  color: var(--app-ink);
}

.cm-host .cm-editor.cm-focused {
  outline: none;
}

.cm-host .cm-scroller {
  font-family: inherit;
  line-height: 1.65;
}

.cm-host .cm-gutters {
  background: var(--app-bg-raised);
  border-right: 1px solid var(--app-border);
  color: var(--app-ink-3);
}

.cm-host .cm-lineNumbers .cm-gutterElement {
  color: var(--app-ink-3);
}

.cm-host .cm-cursor,
.cm-host .cm-dropCursor {
  border-left: 1.5px solid var(--app-accent-warm);
}

/* 自绘黑色 I-beam，规避 Windows + Chromium GPU 合成层下
   系统光标位图时黑时白的问题（白色主题缓存会在刷新后误取） */
.cm-host,
.cm-host .cm-editor,
.cm-host .cm-scroller,
.cm-host .cm-content,
.cm-host .cm-line {
  cursor:
    url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='13' height='20' viewBox='0 0 13 20'><g fill='none' stroke-linecap='round'><g stroke='white' stroke-width='2.6'><line x1='6.5' y1='2.5' x2='6.5' y2='17.5'/><line x1='3.5' y1='2.75' x2='9.5' y2='2.75'/><line x1='3.5' y1='17.25' x2='9.5' y2='17.25'/></g><g stroke='black' stroke-width='1.2'><line x1='6.5' y1='2.5' x2='6.5' y2='17.5'/><line x1='3.5' y1='2.75' x2='9.5' y2='2.75'/><line x1='3.5' y1='17.25' x2='9.5' y2='17.25'/></g></g></svg>")
      6 10,
    text;
}

/* 选区颜色：CM6 默认两条路径同时画选区 ——
     a) drawSelection 扩展插入 .cm-selectionBackground 矩形（默认 #d7d4f0 浅紫）
     b) 浏览器原生 ::selection 由我们全局规则上色（暖橙 + 白字）
   两层叠加导致字符上一种色、空白处另一种色；原生那层还会把字色强制成白。
   彻底修法：把 CM6 的矩形隐去，只留原生 ::selection 一条路径，并就近
   覆盖背景色与字色。currentColor 比 inherit 在 ::selection 内更可靠 ——
   旧版本 Chrome 对 ::selection { color: inherit } 有计算时机的 bug。 */
.cm-host .cm-selectionBackground,
.cm-host .cm-editor .cm-selectionLayer .cm-selectionBackground,
.cm-host .cm-editor.cm-focused
  > .cm-scroller
  > .cm-selectionLayer
  .cm-selectionBackground {
  background: transparent !important;
}

/* CM6 的 hideNativeSelection 把 .cm-line ::selection 的 background-color 强制
   置为 transparent；要 override 需要更高的特异性。.cm-host .cm-content ::selection
   = (0,2,1)，胜过 .cm-line ::selection = (0,1,1)。!important 锁死。
   ::selection / ::-moz-selection 必须分两条规则，否则任一未识别的伪元素
   会让整条规则被浏览器丢弃。 */
.cm-host .cm-content ::selection,
.cm-host .cm-content::selection,
.cm-host .cm-line ::selection,
.cm-host .cm-line::selection {
  background-color: rgba(217, 119, 87, 0.28) !important;
  color: currentColor !important;
}
.cm-host .cm-content ::-moz-selection,
.cm-host .cm-content::-moz-selection,
.cm-host .cm-line ::-moz-selection,
.cm-host .cm-line::-moz-selection {
  background-color: rgba(217, 119, 87, 0.28) !important;
  color: currentColor !important;
}

.cm-host .cm-activeLine {
  background: rgba(217, 119, 87, 0.05);
}

.cm-host .cm-activeLineGutter {
  background: rgba(217, 119, 87, 0.08);
  color: var(--app-ink-2);
}

/* ═══════════════════════════════════════
   SwitchControl —— 原生 checkbox + 暖橙轨道
═══════════════════════════════════════ */
.switch-control {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  cursor: pointer;
  user-select: none;
}

.switch-control.is-disabled {
  cursor: not-allowed;
  opacity: 0.55;
}

/* 真正的 checkbox 视觉上隐藏，仅供 a11y / 键盘聚焦 */
.switch-control-input {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  border: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

.switch-control-track {
  position: relative;
  display: inline-block;
  width: 30px;
  height: 18px;
  border-radius: 999px;
  background: rgba(15, 23, 42, 0.18);
  transition: background var(--duration-normal) var(--ease-default);
  flex: none;
}

.switch-control-thumb {
  position: absolute;
  top: 2px;
  left: 2px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: #ffffff;
  box-shadow: 0 1px 2px rgba(15, 23, 42, 0.18);
  transition: transform var(--duration-normal) var(--ease-default);
}

.switch-control-input:checked + .switch-control-track {
  background: var(--app-accent);
}

.switch-control-input:checked + .switch-control-track .switch-control-thumb {
  transform: translateX(12px);
}

.switch-control:hover .switch-control-input:checked + .switch-control-track {
  background: var(--app-accent-warm);
}

/* 键盘聚焦环 —— 落在 track 上而不是隐藏的 input */
.switch-control-input:focus-visible + .switch-control-track {
  box-shadow:
    0 0 0 2px var(--app-bg-overlay),
    0 0 0 4px rgba(217, 119, 87, 0.45);
}

/* ═══════════════════════════════════════
   滚动条
═══════════════════════════════════════ */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

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

::-webkit-scrollbar-thumb {
  background: var(--app-border-strong);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--color-border-strong);
}

/* ═══════════════════════════════════════
   动画
═══════════════════════════════════════ */
@keyframes fadeInDown {
  from {
    opacity: 0;
    transform: translateY(-24px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(24px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

/* ═══════════════════════════════════════
   响应式
═══════════════════════════════════════ */
@media (max-width: 1200px) {
  .main-content {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .btn-primary:hover,
  .btn-secondary:hover,
  .btn-accent:hover {
    transform: none;
  }

  .btn-primary:hover {
    background: var(--app-accent);
    box-shadow: 0 6px 18px rgba(217, 119, 87, 0.3);
  }

  .btn-secondary:hover {
    background: transparent;
    border-color: var(--app-border-strong);
  }

  .btn-accent:hover {
    background: rgba(217, 119, 87, 0.08);
    border-color: rgba(217, 119, 87, 0.22);
  }

  .background-toggle:hover,
  .colorize-toggle:hover,
  .attrs-toggle:hover,
  .history-toggle:hover {
    transform: none;
    border-color: var(--app-border);
    box-shadow: 0 2px 8px rgba(20, 20, 19, 0.06);
  }

  .btn-primary:active {
    transform: scale(1.04);
  }

  .btn-secondary:active,
  .btn-accent:active {
    transform: scale(1.04);
  }

  .background-toggle:active,
  .colorize-toggle:active,
  .attrs-toggle:active,
  .history-toggle:active {
    transform: scale(1.1);
  }

  .app-container {
    padding: 20px 16px 24px;
  }

  .header {
    margin-bottom: 28px;
  }

  .header h1 {
    font-size: clamp(1.8rem, 6vw, 2.4rem);
  }

  .header p {
    font-size: 0.96rem;
  }

  /* 移动端窄屏：让长行可以折回，避免横向溢出屏幕 */
  .header-hint-row {
    white-space: normal;
  }

  .main-content {
    gap: 20px;
  }

  .card-header {
    padding: 14px 18px;
    min-height: 56px;
  }

  .card-content {
    padding: 18px;
    gap: 16px;
  }

  .card-title {
    font-size: 1.02rem;
  }

  .cm-host {
    height: 320px;
  }
  .cm-host .cm-editor {
    font-size: 13px;
  }

  .button-group {
    gap: 10px;
  }

  .btn {
    height: 44px;
    font-size: 0.9rem;
  }

  .btn-sm {
    height: 36px;
    font-size: 0.78rem;
  }

  .diagram-container {
    min-height: 420px;
  }
}

@media (max-width: 480px) {
  .app-container {
    padding: 16px 12px 24px;
  }

  .header {
    margin-bottom: 22px;
  }

  .header-eyebrow {
    font-size: 0.68rem;
  }

  .header h1 {
    font-size: 1.7rem;
    letter-spacing: -0.02em;
  }

  .header p {
    font-size: 0.88rem;
  }

  .main-content {
    gap: 16px;
  }

  .card {
    border-radius: var(--radius-lg);
  }

  .card-header {
    padding: 12px 14px;
  }

  .card-content {
    padding: 14px;
    gap: 12px;
  }

  .card-title {
    font-size: 0.96rem;
  }

  .cm-host {
    height: 260px;
  }
  .cm-host .cm-editor {
    font-size: 12px;
  }

  .diagram-container {
    min-height: 320px;
    background-size: 18px 18px;
  }

  .legend-item {
    font-size: 0.72rem;
    padding: 3px 9px;
  }

  .btn {
    height: 42px;
    font-size: 0.85rem;
    padding: 0 14px;
  }

  .btn-sm {
    height: 32px;
    font-size: 0.72rem;
    padding: 0 12px;
  }

  /* 手机版：隐藏图例，居中控制区 */
  .output-section .card-header > div:first-child > div:last-child {
    display: none !important;
  }

  .output-section .card-header {
    justify-content: center !important;
    flex-wrap: wrap;
  }

  .output-section .card-header > div:last-child {
    margin: 0 !important;
    justify-content: center;
    flex-wrap: wrap;
    gap: 8px !important;
  }

  .card-header > div:last-child .switch-control {
    transform: scale(0.92);
  }
}

/* ═══════════════════════════════════════
   返回主页按钮（右上胶囊）
═══════════════════════════════════════ */
.back-home {
  position: absolute;
  top: 20px;
  right: 160px;
  z-index: 9999;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: color-mix(in srgb, var(--app-bg-overlay) 92%, transparent);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  border: 1px solid var(--app-border);
  border-radius: 999px;
  box-shadow: 0 2px 10px rgba(20, 20, 19, 0.06);
  color: var(--app-ink-2);
  text-decoration: none;
  transition:
    opacity var(--duration-slow) var(--ease-default),
    border-color var(--duration-normal) var(--ease-default),
    box-shadow var(--duration-normal) var(--ease-default),
    color var(--duration-normal) var(--ease-default),
    transform var(--duration-normal) var(--ease-default);
}

.back-home:hover {
  color: var(--app-ink);
  border-color: var(--app-border-strong);
  box-shadow: 0 4px 12px rgba(20, 20, 19, 0.1);
  transform: translateY(-1px);
}

.back-home svg {
  width: 18px;
  height: 18px;
}

.back-home:focus-visible {
  outline: 2px solid var(--app-accent);
  outline-offset: 3px;
}

/* 历史面板打开时淡出返回按钮 */
body.history-open .back-home {
  opacity: 0;
  pointer-events: none;
}

@media (max-width: 500px) {
  .back-home {
    top: 14px;
    right: 128px;
    width: 36px;
    height: 36px;
  }

  .back-home svg {
    width: 16px;
    height: 16px;
  }
}

/* ═══════════════════════════════════════
   主题切换按钮（右上胶囊）
═══════════════════════════════════════ */
.theme-toggle {
  position: absolute;
  top: 20px;
  right: 100px;
  z-index: 9999;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: color-mix(in srgb, var(--app-bg-overlay) 92%, transparent);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  border: 1px solid var(--app-border);
  border-radius: 999px;
  box-shadow: 0 2px 10px rgba(20, 20, 19, 0.06);
  color: var(--app-ink-2);
  cursor: pointer;
  transition:
    opacity var(--duration-slow) var(--ease-default),
    border-color var(--duration-normal) var(--ease-default),
    box-shadow var(--duration-normal) var(--ease-default),
    color var(--duration-normal) var(--ease-default),
    transform var(--duration-normal) var(--ease-default);
}

.theme-toggle:hover {
  color: var(--app-ink);
  border-color: var(--app-border-strong);
  box-shadow: 0 4px 12px rgba(20, 20, 19, 0.1);
  transform: translateY(-1px);
}

.theme-toggle svg {
  width: 18px;
  height: 18px;
}

.theme-toggle:focus-visible {
  outline: 2px solid var(--app-accent);
  outline-offset: 3px;
}

/* 历史面板打开时淡出主题切换按钮 */
body.history-open .theme-toggle {
  opacity: 0;
  pointer-events: none;
}

@media (max-width: 500px) {
  .theme-toggle {
    top: 14px;
    right: 76px;
    width: 36px;
    height: 36px;
  }

  .theme-toggle svg {
    width: 16px;
    height: 16px;
  }
}

/* ═══════════════════════════════════════
   语言切换器（右上胶囊）
═══════════════════════════════════════ */
.lang-switch {
  position: absolute;
  top: 20px;
  right: 20px;
  z-index: 9999;
  display: inline-flex;
  align-items: center;
  padding: 4px;
  gap: 0;
  background: color-mix(in srgb, var(--app-bg-overlay) 92%, transparent);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  border: 1px solid var(--app-border);
  border-radius: 999px;
  box-shadow: 0 2px 10px rgba(20, 20, 19, 0.06);
  transition:
    opacity var(--duration-slow) var(--ease-default),
    border-color var(--duration-normal) var(--ease-default),
    box-shadow var(--duration-normal) var(--ease-default);
}

/* 历史面板打开时淡出语言胶囊 —— 它 z-index:9999 比覆盖层高，
   不隐藏会一直浮在 3D 卡片之上 */
body.history-open .lang-switch {
  opacity: 0;
  pointer-events: none;
}

.lang-switch:hover {
  border-color: var(--app-border-strong);
  box-shadow: 0 6px 16px rgba(20, 20, 19, 0.08);
}

.lang-switch .lang-option {
  position: relative;
  z-index: 1;
  width: 32px;
  height: 32px;
  border: 0;
  padding: 0;
  margin: 0;
  background: transparent;
  cursor: pointer;
  font-family: var(--app-font);
  font-size: 0.78rem;
  font-weight: var(--weight-medium);
  letter-spacing: 0.02em;
  color: var(--app-ink-3);
  border-radius: 50%;
  display: grid;
  place-items: center;
  transition: color 260ms var(--ease-default);
}

.lang-switch .lang-option:hover {
  color: var(--app-ink-2);
}

.lang-switch .lang-option.is-active {
  color: var(--app-ink);
}

.lang-switch .lang-thumb {
  position: absolute;
  top: 4px;
  left: 4px;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--app-bg-raised);
  box-shadow:
    0 1.5px 4px rgba(20, 20, 19, 0.1),
    0 0 0 1px var(--app-border);
  transition: transform 380ms cubic-bezier(0.32, 0.72, 0.28, 1);
  pointer-events: none;
}

.lang-switch[data-lang="en"] .lang-thumb {
  transform: translateX(32px);
}

.lang-switch:focus-within {
  border-color: var(--app-accent);
  box-shadow: 0 0 0 3px rgba(217, 119, 87, 0.18);
}

.lang-switch .lang-option:focus-visible {
  outline: none;
}

/* 语言切换：整页平滑过渡 */
.lang-fade-target {
  transition: opacity 220ms var(--ease-default);
}

body.is-lang-fading .lang-fade-target {
  opacity: 0.28;
}

@media (max-width: 500px) {
  .lang-switch {
    top: 14px;
    right: 14px;
  }

  .lang-switch .lang-option,
  .lang-switch .lang-thumb {
    width: 28px;
    height: 28px;
    font-size: 0.72rem;
  }

  .lang-switch[data-lang="en"] .lang-thumb {
    transform: translateX(28px);
  }
}

/* ═══════════════════════════════════════
   GitHub Corner（左上暖橙折角）
═══════════════════════════════════════ */
.github-corner {
  position: absolute;
  top: 0;
  left: 0;
  z-index: 9999;
  border: 0;
  width: 68px;
  height: 68px;
  overflow: hidden;
  display: block;
}

.github-corner svg {
  position: absolute;
  top: 0;
  left: 0;
  width: 68px;
  height: 68px;
  border: 0;
  fill: var(--app-accent);
  color: #faf9f5;
  transform: scaleX(-1);
  transition: fill var(--duration-normal) var(--ease-default);
}

.github-corner:hover svg {
  fill: var(--app-accent-warm);
}

.github-corner .octo-arm {
  transform-origin: 130px 106px;
}

.github-corner:hover .octo-arm {
  animation: octocat-wave 640ms var(--ease-default);
}

.github-corner:focus-visible {
  outline: none;
}

.github-corner:focus-visible svg {
  fill: var(--app-accent-warm);
}

@keyframes octocat-wave {
  0%,
  100% {
    transform: rotate(0);
  }

  20%,
  60% {
    transform: rotate(-25deg);
  }

  40%,
  80% {
    transform: rotate(10deg);
  }
}

@media (max-width: 500px) {
  .github-corner {
    width: 54px;
    height: 54px;
  }

  .github-corner svg {
    width: 54px;
    height: 54px;
  }

  .github-corner:hover .octo-arm {
    animation: none;
  }

  .github-corner .octo-arm {
    animation: octocat-wave 640ms var(--ease-default);
  }
}

/* ═══════════════════════════════════════
   深色模式（支持系统偏好和手动切换）
═══════════════════════════════════════ */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) body::before,
  :root:not([data-theme]) .input-textarea,
  :root:not([data-theme]) .cm-host,
  :root:not([data-theme]) .diagram-container {
    background:
      radial-gradient(
        ellipse 60% 50% at 12% 0%,
        rgba(217, 119, 87, 0.12) 0%,
        transparent 60%
      ),
      radial-gradient(
        ellipse 45% 45% at 100% 100%,
        rgba(106, 155, 204, 0.08) 0%,
        transparent 55%
      );
  }

  :root:not([data-theme]) .input-textarea,
  :root:not([data-theme]) .cm-host {
    background: var(--color-bg-overlay);
    color: var(--app-ink);
  }

  :root:not([data-theme]) .diagram-container {
    background-color: #ffffff;
  }

  :root:not([data-theme]) ::-webkit-scrollbar-thumb {
    background: var(--color-border-default);
  }
}

/* 手动切换深色模式 */
:root[data-theme="dark"] body::before {
  background:
    radial-gradient(
      ellipse 60% 50% at 12% 0%,
      rgba(217, 119, 87, 0.12) 0%,
      transparent 60%
    ),
    radial-gradient(
      ellipse 45% 45% at 100% 100%,
      rgba(106, 155, 204, 0.08) 0%,
      transparent 55%
    );
}

:root[data-theme="dark"] .input-textarea,
:root[data-theme="dark"] .cm-host {
  background: var(--color-bg-overlay);
  color: var(--app-ink);
}

:root[data-theme="dark"] .diagram-container {
  background-color: #ffffff;
}

:root[data-theme="dark"] ::-webkit-scrollbar-thumb {
  background: var(--color-border-default);
}

/* ═══════════════════════════════════════
   动效导出按钮
═══════════════════════════════════════ */
.export-btn-wrap {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  justify-content: flex-end;
}

.export-btn {
  position: relative;
  height: 52px;
  padding: 0;
  border: 0;
  border-radius: 9999px;
  color: #fff;
  background: linear-gradient(to bottom, #262626, #171717);
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.1),
    0 16px 32px -10px rgba(0, 0, 0, 0.3);
  cursor: pointer;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  white-space: nowrap;
  font-family: var(--app-font);
  transition:
    width 560ms cubic-bezier(0.32, 0.72, 0, 1),
    transform 560ms cubic-bezier(0.32, 0.72, 0, 1),
    box-shadow 560ms cubic-bezier(0.32, 0.72, 0, 1);
}

.export-btn[data-state="idle"] { width: 140px; }
.export-btn[data-state="open"] { width: 296px; cursor: default; }
.export-btn[data-state="loading"] { width: 200px; cursor: default; }
.export-btn[data-state="success"] { width: 180px; cursor: default; }

.export-btn[data-state="idle"]:hover {
  transform: scale(1.02);
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.1),
    0 20px 40px -10px rgba(0, 0, 0, 0.4);
}
.export-btn[data-state="idle"]:active {
  transform: scale(0.97);
}
.export-btn:focus-visible {
  outline: none;
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.1),
    0 16px 32px -10px rgba(0, 0, 0, 0.3),
    0 0 0 2px var(--app-bg),
    0 0 0 4px var(--app-accent);
}
.export-btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
  transform: none !important;
}

.export-progress {
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 0;
  background: rgba(255, 255, 255, 0.1);
  transition: width 300ms cubic-bezier(0, 0, 0.2, 1);
  pointer-events: none;
}

.export-view {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  width: 100%;
  opacity: 0;
  transform: translateY(6px);
  pointer-events: none;
  white-space: nowrap;
  transition:
    opacity 240ms ease,
    transform 340ms cubic-bezier(0.32, 0.72, 0, 1);
}
.export-view.is-on {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

.export-view-idle .idle-label {
  font-weight: 600;
  letter-spacing: 0.14em;
  font-size: 15px;
}
.export-view-idle .arrow-icon {
  color: #d4d4d4;
  transition: transform 340ms cubic-bezier(0.32, 0.72, 0, 1);
}
.export-btn[data-state="idle"]:hover .export-view-idle .arrow-icon {
  transform: translateY(2px);
}

.export-view-open {
  padding: 0 6px;
  gap: 0;
  justify-content: space-between;
}
.export-opt {
  flex: 1;
  height: 40px;
  border-radius: 9999px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: background 200ms ease;
}
.export-opt:hover {
  background: rgba(64, 64, 64, 0.5);
}
.export-opt-label {
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: #d4d4d4;
  pointer-events: none;
  transition: color 200ms ease;
}
.export-opt[data-fmt="PNG"]:hover .export-opt-label { color: #60a5fa; }
.export-opt[data-fmt="SVG"]:hover .export-opt-label { color: #34d399; }
.export-opt[data-fmt="XML"]:hover .export-opt-label { color: #f59e0b; }

.export-sep {
  width: 1px;
  height: 18px;
  background: #404040;
  margin: 0 2px;
  transition: opacity 200ms ease;
  flex: 0 0 1px;
}
.export-view-open:hover .export-sep {
  opacity: 0.4;
}

.export-cancel {
  width: 40px;
  height: 40px;
  flex: 0 0 40px;
  border-radius: 9999px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #a3a3a3;
  cursor: pointer;
  transition: background 200ms ease, color 200ms ease;
}
.export-cancel:hover {
  background: rgba(64, 64, 64, 0.5);
  color: #fff;
}
.export-cancel svg {
  pointer-events: none;
}

.export-view-loading .export-spinner {
  width: 16px;
  height: 16px;
  color: #a3a3a3;
  animation: export-spin 800ms linear infinite;
}
@keyframes export-spin {
  to { transform: rotate(360deg); }
}
.export-view-loading .loading-label {
  font-size: 14px;
  color: #e5e5e5;
  font-weight: 500;
  letter-spacing: 0.02em;
}

.export-view-success .check-icon {
  width: 16px;
  height: 16px;
  color: #34d399;
}
.export-view-success .check-icon path {
  stroke-dasharray: 18;
  stroke-dashoffset: 18;
}
.export-view-success.is-on .check-icon path {
  animation: export-draw 460ms cubic-bezier(0.32, 0.72, 0, 1) 180ms forwards;
}
@keyframes export-draw {
  to { stroke-dashoffset: 0; }
}
.export-view-success .success-label {
  font-size: 14px;
  color: #34d399;
  font-weight: 500;
  letter-spacing: 0.02em;
}

/* ═══════════════════════════════════════
   焦点样式（可访问性）
═══════════════════════════════════════ */
.btn:focus-visible,
.background-toggle:focus-visible,
.colorize-toggle:focus-visible,
.attrs-toggle:focus-visible,
.history-toggle:focus-visible,
.github-corner:focus-visible {
  outline: 2px solid var(--app-accent);
  outline-offset: 3px;
}

/* ═══════════════════════════════════════
   生成历史（History Overlay）
   暖色玻璃磨砂层 + 3D 透视卡片轨道。
   - 拖拽 / 滚轮 / 吸附等动效逻辑由 JS 直接写入 .history-card 的 inline
     transform / opacity / zIndex；这里禁止给 .history-card 的 transform
     加 transition，否则会和 rAF 循环打架。
   - JS 还会在每张卡上写 --shift（0~1，焦点卡为 1），下面用它驱动
     覆盖层透明度和操作按钮的渐显。
═══════════════════════════════════════ */
.history-overlay {
  position: fixed;
  inset: 0;
  z-index: 1000;
  background: color-mix(in srgb, var(--app-bg) 68%, transparent);
  backdrop-filter: blur(28px) saturate(140%);
  -webkit-backdrop-filter: blur(28px) saturate(140%);
  color: var(--app-ink);
  overflow: hidden;
  user-select: none;
  -webkit-user-select: none;
  touch-action: none;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--duration-slow) var(--ease-default);
}
.history-overlay.is-open {
  opacity: 1;
  pointer-events: auto;
}
/* pointer-events 不会向子元素级联：父级 none 时，子元素显式 auto（如按钮、
   .history-card-actions）仍能收到点击。面板关闭时把所有后代一并屏蔽，
   否则恢复/删除按钮所在的位置在面板隐藏后还是可点。 */
.history-overlay:not(.is-open) * {
  pointer-events: none !important;
}
/* 左下暖橙晕染 + 右上浅沙色，营造温暖深度而非冷调 AI 感 */
.history-overlay::before {
  content: "";
  position: absolute;
  inset: auto auto -18% -10%;
  width: 55%;
  height: 70%;
  background: radial-gradient(
    ellipse at center,
    rgba(217, 119, 87, 0.18) 0%,
    transparent 65%
  );
  filter: blur(40px);
  pointer-events: none;
}
.history-overlay::after {
  content: "";
  position: absolute;
  inset: -10% -12% auto auto;
  width: 48%;
  height: 58%;
  background: radial-gradient(
    ellipse at center,
    rgba(196, 185, 154, 0.24) 0%,
    transparent 70%
  );
  filter: blur(40px);
  pointer-events: none;
}

/* ── Header ───────────────────────────────── */
.history-header {
  position: absolute;
  top: clamp(24px, 3vw, 36px);
  left: clamp(24px, 3vw, 40px);
  z-index: 5;
  pointer-events: none;
  display: flex;
  align-items: baseline;
  gap: 14px;
  font-family: var(--app-font-display);
  font-weight: var(--weight-regular);
  font-size: clamp(1.5rem, 2vw, 1.85rem);
  line-height: var(--leading-cn-tight);
  letter-spacing: -0.015em;
  color: var(--app-ink);
}
.history-header > svg {
  position: relative;
  top: 2px;
  width: 0.78em;
  height: 0.78em;
  color: var(--app-accent-warm);
}
.history-header .history-count {
  font-family: var(--app-font);
  font-weight: var(--weight-light);
  font-size: 0.72em;
  letter-spacing: 0.04em;
  color: var(--app-ink-2);
}

/* ── Close ───────────────────────────────── */
.history-close {
  position: absolute;
  top: clamp(20px, 2.4vw, 28px);
  right: clamp(20px, 2.4vw, 32px);
  z-index: 5;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: 1px solid var(--app-border);
  background: color-mix(in srgb, var(--app-bg-overlay) 85%, transparent);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
  color: var(--app-ink);
  display: grid;
  place-items: center;
  cursor: pointer;
  transition:
    transform var(--duration-fast) var(--ease-default),
    background var(--duration-normal) var(--ease-default),
    border-color var(--duration-normal) var(--ease-default),
    color var(--duration-normal) var(--ease-default);
}
.history-close:hover {
  transform: scale(1.06);
  background: var(--app-bg-overlay);
  border-color: var(--app-accent);
  color: var(--app-accent-warm);
}
.history-close:active {
  transform: scale(0.95);
}
.history-close:focus-visible {
  outline: 2px solid var(--app-accent);
  outline-offset: 3px;
}

/* ── Hint pill ───────────────────────────────── */
.history-hint {
  position: absolute;
  bottom: clamp(28px, 4vw, 44px);
  left: 50%;
  transform: translateX(-50%);
  z-index: 5;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 22px;
  border-radius: var(--radius-full);
  border: 1px solid var(--app-border);
  background: color-mix(in srgb, var(--app-bg-overlay) 88%, transparent);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  color: var(--app-ink-2);
  font-family: var(--app-font);
  font-size: var(--text-cn-sm);
  letter-spacing: 0.01em;
  pointer-events: none;
  transition: opacity 600ms var(--ease-default);
  box-shadow: 0 8px 24px rgba(20, 20, 19, 0.06);
}
.history-hint > svg {
  color: var(--app-accent);
  animation: history-bounce 1.4s ease-in-out infinite;
}
@keyframes history-bounce {
  0%,
  100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-3px);
  }
}

/* ── Empty state ───────────────────────────────── */
.history-empty {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  pointer-events: none;
  text-align: center;
}
.history-empty-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-8) var(--space-10);
  max-width: 360px;
}
.history-empty-icon-wrap {
  width: 88px;
  height: 88px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: color-mix(in srgb, var(--app-accent) 10%, var(--app-bg-overlay));
  border: 1px solid color-mix(in srgb, var(--app-accent) 28%, transparent);
  margin-bottom: var(--space-2);
  box-shadow: 0 8px 24px rgba(217, 119, 87, 0.12);
}
.history-empty-icon-wrap > svg {
  width: 30px;
  height: 30px;
  color: var(--app-accent-warm);
}
.history-empty-title {
  font-family: var(--app-font-display);
  font-weight: var(--weight-regular);
  font-size: var(--text-xl);
  line-height: var(--leading-cn-snug);
  letter-spacing: -0.01em;
  color: var(--app-ink);
}
.history-empty-hint {
  font-family: var(--app-font);
  font-size: var(--text-cn-sm);
  line-height: var(--leading-cn-normal);
  color: var(--app-ink-2);
}

/* ── Track + cards ───────────────────────────────── */
.history-track {
  position: absolute;
  inset: 0;
  perspective: 1400px;
  perspective-origin: 50% 50%;
  transform-style: preserve-3d;
  cursor: grab;
}
.history-track.is-dragging {
  cursor: grabbing;
}

/* JS 直接写 transform / opacity / zIndex；这里只过渡 box-shadow */
.history-card {
  position: absolute;
  left: 50%;
  top: 50%;
  width: 320px;
  height: 420px;
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--app-bg-overlay);
  box-shadow:
    0 30px 60px -16px rgba(20, 20, 19, 0.32),
    0 8px 16px -8px rgba(20, 20, 19, 0.18);
  transform-style: preserve-3d;
  will-change: transform;
  transition: box-shadow var(--duration-slow) var(--ease-default);
}
@media (max-width: 768px) {
  .history-card {
    width: 260px;
    height: 360px;
  }
}

.history-card-thumb {
  position: absolute;
  /* 给顶部留一点呼吸空间，缩略图整体上靠：底部交给 meta / shade */
  inset: 18px 16px 38% 16px;
  background-color: var(--app-bg-overlay);
  background-size: contain;
  background-position: center top;
  background-repeat: no-repeat;
  pointer-events: none;
}
.history-card-thumb.is-empty {
  background: linear-gradient(
    135deg,
    var(--app-bg-raised) 0%,
    color-mix(in srgb, var(--color-accent-sand) 22%, var(--app-bg-raised)) 100%
  );
  display: grid;
  place-items: center;
  color: var(--app-ink-3);
  font-size: 36px;
}

/* 非焦点卡：盖一层暖米色让背景里其它卡稍微"沉"下去；
   焦点卡 shift→1，覆盖层透明度趋近 0，缩略图更清晰 */
.history-card-track-overlay {
  position: absolute;
  inset: 0;
  background: color-mix(in srgb, var(--app-bg) 55%, transparent);
  pointer-events: none;
  opacity: calc(0.55 - var(--shift, 0) * 0.55);
}
/* 底部暖白渐变，给 meta 文字一个可读区域而不遮挡缩略图 */
.history-card-shade {
  position: absolute;
  inset: 0;
  background: linear-gradient(
    to top,
    var(--app-bg-overlay) 0%,
    color-mix(in srgb, var(--app-bg-overlay) 70%, transparent) 30%,
    transparent 58%
  );
  pointer-events: none;
}

.history-card-meta {
  position: absolute;
  inset: auto 0 0 0;
  z-index: 2;
  padding: 20px 22px 22px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  pointer-events: none;
  font-family: var(--app-font);
}
.history-card-eyebrow {
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  font-weight: var(--weight-semibold);
  color: var(--app-accent-warm);
}
.history-card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}
.history-card-tags span {
  display: inline-flex;
  align-items: center;
  padding: 3px 10px;
  border-radius: var(--radius-full);
  background: color-mix(in srgb, var(--app-bg-raised) 80%, transparent);
  border: 1px solid var(--app-border);
  color: var(--app-ink-2);
  font-size: 11px;
  letter-spacing: 0.02em;
}
.history-card-actions {
  margin-top: 4px;
  display: flex;
  align-items: center;
  gap: 12px;
  pointer-events: auto;
  opacity: var(--shift, 0);
  transform: translateY(calc((1 - var(--shift, 0)) * 16px));
}
.history-card-restore {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 9px 18px;
  border-radius: var(--radius-full);
  border: 1px solid var(--app-accent);
  background: var(--app-accent);
  color: #fff;
  font-family: var(--app-font);
  font-size: 13px;
  font-weight: var(--weight-medium);
  letter-spacing: 0.01em;
  cursor: pointer;
  transition:
    transform var(--duration-fast) var(--ease-default),
    background var(--duration-fast) var(--ease-default),
    border-color var(--duration-fast) var(--ease-default),
    box-shadow var(--duration-normal) var(--ease-default);
  box-shadow: 0 6px 16px rgba(217, 119, 87, 0.28);
}
.history-card-restore:hover {
  transform: translateY(-1px);
  background: var(--app-accent-warm);
  border-color: var(--app-accent-warm);
  box-shadow: 0 10px 22px rgba(201, 100, 66, 0.32);
}
.history-card-restore:active {
  transform: translateY(0) scale(0.97);
}
.history-card-delete {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 14px;
  border-radius: var(--radius-full);
  border: 1px solid var(--app-border);
  background: transparent;
  color: var(--app-ink-2);
  font-family: var(--app-font);
  font-size: 12px;
  cursor: pointer;
  transition:
    color var(--duration-fast) var(--ease-default),
    border-color var(--duration-fast) var(--ease-default),
    background var(--duration-fast) var(--ease-default);
}
.history-card-delete:hover {
  color: var(--color-error);
  border-color: color-mix(in srgb, var(--color-error) 45%, transparent);
  background: color-mix(in srgb, var(--color-error) 8%, transparent);
}
.history-card-restore:focus-visible,
.history-card-delete:focus-visible {
  outline: 2px solid var(--app-accent);
  outline-offset: 2px;
}

.history-card-frame {
  position: absolute;
  inset: 0;
  border-radius: var(--radius-lg);
  border: 1px solid color-mix(in srgb, var(--app-ink) 8%, transparent);
  pointer-events: none;
}