/* ========================================================================
   R2 Manager — Modern CSS
   Features: CSS nesting, light-dark(), color-mix(), @starting-style,
             Popover API, range media queries, text-wrap: balance
   ======================================================================== */

@layer reset, tokens, base, layout, components, utilities, animations;

/* --- Reset --- */
@layer reset {
  *, *::before, *::after { box-sizing: border-box; }
  * { margin: 0; padding: 0; }
  html { -webkit-text-size-adjust: 100%; }
  body { min-height: 100dvh; }
  img, svg, video, canvas { display: block; max-width: 100%; }
  button, input, select, textarea { font: inherit; color: inherit; }
  button { cursor: pointer; border: none; background: none; }
  a { color: inherit; text-decoration: none; }
  ul, ol { list-style: none; }
  [hidden] { display: none !important; }
  dialog { border: none; padding: 0; max-width: unset; max-height: unset; }
  dialog::backdrop { background: transparent; }
}

/* --- Design Tokens --- */
@layer tokens {
  :root {
    color-scheme: light dark;

    /* Spacing */
    --sp-1: 4px;
    --sp-2: 8px;
    --sp-3: 12px;
    --sp-4: 16px;
    --sp-5: 20px;
    --sp-6: 24px;
    --sp-8: 32px;
    --sp-10: 40px;
    --sp-12: 48px;

    /* Typography */
    --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    --font-mono: "SF Mono", SFMono-Regular, Consolas, "Liberation Mono", Menlo, monospace;
    --text-xs: 11px;
    --text-sm: 12px;
    --text-base: 13px;
    --text-md: 14px;
    --text-lg: 16px;

    /* Radii */
    --radius-sm: 4px;
    --radius-md: 6px;
    --radius-lg: 8px;
    --radius-xl: 12px;

    /* Accent */
    --accent: #F6821F;
    --accent-hover: color-mix(in oklch, var(--accent) 82%, black);
    --accent-subtle: color-mix(in oklch, var(--accent) 12%, transparent);

    /* Transitions */
    --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
    --duration-fast: 120ms;
    --duration-normal: 200ms;
    --duration-slow: 300ms;

    /* Z-index */
    --z-dropzone: 100;
    --z-upload-panel: 90;
    --z-context-menu: 200;
    --z-dialog: 300;
    --z-toast: 400;

    /* Theme colors — single declaration via light-dark() */
    --bg-primary: light-dark(#ffffff, #1a1a1a);
    --bg-secondary: light-dark(#f5f5f5, #222222);
    --bg-tertiary: light-dark(#ebebeb, #2a2a2a);
    --bg-hover: light-dark(
      color-mix(in oklch, black 4%, transparent),
      color-mix(in oklch, white 5%, transparent)
    );
    --bg-active: light-dark(
      color-mix(in oklch, black 7%, transparent),
      color-mix(in oklch, white 8%, transparent)
    );
    --border: light-dark(#e0e0e0, #333333);
    --border-subtle: light-dark(#eeeeee, #2a2a2a);
    --text-primary: light-dark(#1a1a1a, #e8e8e8);
    --text-secondary: light-dark(#666666, #999999);
    --text-tertiary: light-dark(#999999, #666666);
    --text-danger: light-dark(#d32f2f, #ef5350);
    --backdrop: light-dark(
      color-mix(in oklch, black 30%, transparent),
      color-mix(in oklch, black 50%, transparent)
    );
  }

  /* Explicit theme override */
  [data-theme="light"] { color-scheme: light; }
  [data-theme="dark"] { color-scheme: dark; }
}

/* --- Base --- */
@layer base {
  html {
    font-family: var(--font-sans);
    font-size: var(--text-base);
    line-height: 1.5;
    color: var(--text-primary);
    background: var(--bg-primary);
  }

  h1, h2, h3 {
    font-weight: 600;
    line-height: 1.3;
    text-wrap: balance;
  }

  h2 { font-size: var(--text-lg); }

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

  :focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
  }

  /* Scrollbar */
  ::-webkit-scrollbar { width: 6px; height: 6px; }
  ::-webkit-scrollbar-track { background: transparent; }
  ::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: 3px;

    &:hover { background: var(--text-tertiary); }
  }
}

/* --- Layout --- */
@layer layout {
  #app {
    display: grid;
    grid-template-rows: auto auto 1fr;
    min-height: 100dvh;
  }

  .topbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--sp-2) var(--sp-4);
    border-bottom: 1px solid var(--border);
    background: color-mix(in oklch, var(--bg-primary) 80%, transparent);
    backdrop-filter: blur(12px) saturate(180%);
    -webkit-backdrop-filter: blur(12px) saturate(180%);
    position: sticky;
    top: 0;
    z-index: 10;

    & h1 {
      font-size: var(--text-md);
      font-weight: 600;
    }
  }

  .topbar-logo {
    width: 20px;
    height: 20px;
    object-fit: contain;
  }

  .toolbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--sp-2) var(--sp-4);
    border-bottom: 1px solid var(--border-subtle);
    background: var(--bg-primary);
    gap: var(--sp-2);
    flex-wrap: wrap;

    @media (width <= 640px) {
      flex-direction: column;
      align-items: stretch;

      & > .flex { justify-content: flex-end; }
    }
  }

  .file-browser {
    padding: var(--sp-4);
    overflow-y: auto;

    /* Density tokens */
    --fb-grid-min: 160px;
    --fb-gap: var(--sp-3);
    --fb-pad: var(--sp-3);
    --fb-icon: 40px;
    --fb-name: var(--text-sm);

    &[data-density="compact"] {
      --fb-grid-min: 120px;
      --fb-gap: var(--sp-2);
      --fb-pad: var(--sp-2);
      --fb-icon: 32px;
      --fb-name: var(--text-xs);
    }

    &[data-density="loose"] {
      --fb-grid-min: 200px;
      --fb-gap: var(--sp-4);
      --fb-pad: var(--sp-4);
      --fb-icon: 48px;
      --fb-name: var(--text-base);
    }
  }

  .file-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(var(--fb-grid-min), 1fr));
    gap: var(--fb-gap);

    [data-view="list"] > & { grid-template-columns: 1fr; }

    @media (width <= 640px) {
      grid-template-columns: 1fr;
    }
  }
}

/* --- Components --- */
@layer components {

  /* Buttons */
  .btn {
    display: inline-flex;
    align-items: center;
    gap: var(--sp-1);
    padding: var(--sp-2) var(--sp-3);
    font-size: var(--text-base);
    font-weight: 500;
    border-radius: var(--radius-md);
    transition: background var(--duration-fast), color var(--duration-fast);
    white-space: nowrap;

    &.primary {
      background: var(--accent);
      color: #fff;

      &:hover { background: var(--accent-hover); }
    }

    &.secondary {
      background: var(--bg-tertiary);
      color: var(--text-primary);

      &:hover { background: var(--bg-active); }
    }

    &.danger {
      background: var(--text-danger);
      color: #fff;

      &:hover { opacity: 0.9; }
    }

    &.sm {
      padding: var(--sp-1) var(--sp-2);
      font-size: var(--text-sm);
    }
  }

  .icon-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    border-radius: var(--radius-md);
    transition: background var(--duration-fast);
    color: var(--text-secondary);
    flex-shrink: 0;

    &:hover { background: var(--bg-hover); color: var(--text-primary); }
    &.sm { width: 24px; height: 24px; }
  }

  /* Icons */
  .icon { width: 16px; height: 16px; flex-shrink: 0; }
  .icon-lg { width: 20px; height: 20px; }
  .icon-xl { width: 48px; height: 48px; }

  /* Theme toggle icons */
  [data-theme="light"] .icon-moon,
  [data-theme="dark"] .icon-sun { display: none; }

  /* Form Fields */
  .field {
    display: flex;
    flex-direction: column;
    gap: var(--sp-1);
    margin-bottom: var(--sp-3);

    & label {
      font-size: var(--text-sm);
      font-weight: 500;
      color: var(--text-secondary);
    }

    & input,
    & select {
      padding: var(--sp-2) var(--sp-3);
      border: 1px solid var(--border);
      border-radius: var(--radius-md);
      background: var(--bg-primary);
      font-size: var(--text-base);
      transition: border-color var(--duration-fast);

      &:focus {
        outline: none;
        border-color: var(--accent);
      }
    }
  }

  /* Dialogs — entry via @starting-style, centered with inset:0 + margin:auto */
  dialog[open] {
    display: flex;
    flex-direction: column;
    position: fixed;
    inset: 0;
    margin: auto;
    background: color-mix(in oklch, var(--bg-primary) 85%, transparent);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
    border-radius: var(--radius-xl);
    padding: var(--sp-6);
    width: min(440px, calc(100vw - 32px));
    max-height: calc(100dvh - 64px);
    overflow-y: auto;
    z-index: var(--z-dialog);
    opacity: 1;
    transform: scale(1);
    transition:
      opacity var(--duration-normal) var(--ease-out),
      transform var(--duration-normal) var(--ease-out),
      display var(--duration-normal) allow-discrete,
      overlay var(--duration-normal) allow-discrete;

    @starting-style {
      opacity: 0;
      transform: scale(0.96);
    }

    &::backdrop {
      background: var(--backdrop);
      opacity: 1;
      transition:
        opacity var(--duration-normal),
        display var(--duration-normal) allow-discrete,
        overlay var(--duration-normal) allow-discrete;

      @starting-style { opacity: 0; }
    }

    & h2 { margin-bottom: var(--sp-2); }
    & p { margin-bottom: var(--sp-4); font-size: var(--text-sm); }
  }

  /* Breadcrumb */
  .breadcrumb {
    display: flex;
    align-items: center;
    gap: var(--sp-1);
    flex-wrap: wrap;
    min-height: 28px;

    & li {
      display: flex;
      align-items: center;
      gap: var(--sp-1);

      &:not(:last-child)::after {
        content: '';
        display: inline-block;
        width: 12px;
        height: 12px;
        background: currentColor;
        opacity: 0.3;
        mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='currentColor' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='9 18 15 12 9 6'/%3E%3C/svg%3E") center / contain no-repeat;
      }

      &:last-child .breadcrumb-btn {
        color: var(--text-primary);
        font-weight: 500;
      }
    }
  }

  .breadcrumb-btn {
    font-size: var(--text-sm);
    padding: var(--sp-1);
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    transition: color var(--duration-fast), background var(--duration-fast);

    &:hover { color: var(--text-primary); background: var(--bg-hover); }
  }

  /* File Card */
  .file-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: var(--sp-2);
    padding: var(--fb-pad);
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: background var(--duration-fast);
    position: relative;
    min-height: 100px;

    &:hover { background: var(--bg-hover); }
    &:active { background: var(--bg-active); }
    &:hover .file-card-actions { opacity: 1; }
  }

  /* List view card */
  [data-view="list"] .file-card {
    flex-direction: row;
    justify-content: flex-start;
    min-height: unset;
    border-radius: var(--radius-sm);
    gap: var(--sp-3);

    & .file-card-icon,
    & .file-card-thumb { flex-shrink: 0; }
    & .file-card-thumb { width: var(--fb-icon); height: var(--fb-icon); }
    & .file-card-name { flex: 1; min-width: 0; text-align: left; -webkit-line-clamp: 1; line-clamp: 1; }
    & .file-card-size { flex-shrink: 0; width: 72px; text-align: right; }
    & .file-card-date { display: block; flex-shrink: 0; width: 140px; text-align: right; }
    & .file-card-actions { position: static; opacity: 1; }
  }

  /* Grid view mobile → collapse to rows */
  @media (width <= 640px) {
    [data-view="grid"] .file-card {
      flex-direction: row;
      min-height: unset;
      justify-content: flex-start;

      & .file-card-icon { width: 28px; height: 28px; flex-shrink: 0; }
      & .file-card-name { text-align: left; -webkit-line-clamp: 1; line-clamp: 1; }
      & .file-card-size { display: none; }
      & .file-card-actions { opacity: 1; position: static; }
      & .file-card-thumb { width: 40px; aspect-ratio: 1; flex-shrink: 0; }
    }

    [data-view="list"] .file-card .file-card-date { display: none; }
  }

  .file-card-icon {
    width: var(--fb-icon);
    height: var(--fb-icon);
    color: var(--text-tertiary);
    display: flex;
    align-items: center;
    justify-content: center;

    &.folder { color: var(--accent); }
    & svg { width: 100%; height: 100%; }
  }

  .file-card-thumb {
    width: 100%;
    aspect-ratio: 1;
    object-fit: cover;
    border-radius: var(--radius-sm);
    background: var(--bg-secondary);
  }

  .file-card-name {
    font-size: var(--fb-name);
    text-align: center;
    word-break: break-all;
    display: -webkit-box;
    line-clamp: 2;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    width: 100%;
  }

  .file-card-size,
  .file-card-date {
    font-size: var(--text-xs);
    color: var(--text-tertiary);
  }

  .file-card-date { display: none; }

  .file-card-actions {
    position: absolute;
    top: var(--sp-1);
    right: var(--sp-1);
    opacity: 0;
    transition: opacity var(--duration-fast);
  }

  /* Button Group (view toggle) */
  .btn-group {
    display: inline-flex;
    border: 1px solid var(--border);
    border-radius: var(--radius-md);

    & > .icon-btn {
      border-radius: 0;

      &:first-child { border-radius: var(--radius-sm) 0 0 var(--radius-sm); }
      &:last-child { border-radius: 0 var(--radius-sm) var(--radius-sm) 0; }
      &[aria-pressed="true"] { background: var(--bg-active); color: var(--text-primary); }
    }
  }

  /* List view skeleton */
  [data-view="list"] .skeleton-card { min-height: 40px; }

  /* Toast */
  .toast-container {
    position: fixed;
    bottom: var(--sp-4);
    right: var(--sp-4);
    display: flex;
    flex-direction: column;
    gap: var(--sp-2);
    z-index: var(--z-toast);
    pointer-events: none;
  }

  .toast {
    display: flex;
    align-items: center;
    gap: var(--sp-2);
    padding: var(--sp-3) var(--sp-4);
    background: color-mix(in oklch, var(--bg-primary) 85%, transparent);
    backdrop-filter: blur(12px) saturate(180%);
    -webkit-backdrop-filter: blur(12px) saturate(180%);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    font-size: var(--text-sm);
    color: var(--text-secondary);
    max-width: 360px;
    pointer-events: auto;
    animation: toast-in var(--duration-normal) var(--ease-out);

    &.success { color: var(--text-primary); }
    &.error { color: var(--text-danger); }
    &.info { color: var(--text-primary); }
    &.removing { animation: toast-out var(--duration-normal) var(--ease-out) forwards; }
  }

  /* Context Menu — Popover API with @starting-style */
  .context-menu {
    position: fixed;
    inset: unset;
    margin: 0;
    background: color-mix(in oklch, var(--bg-primary) 85%, transparent);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: var(--sp-1);
    min-width: 160px;
    opacity: 1;
    transform: scale(1);
    transition:
      opacity var(--duration-fast) var(--ease-out),
      transform var(--duration-fast) var(--ease-out),
      display var(--duration-fast) allow-discrete,
      overlay var(--duration-fast) allow-discrete;

    @starting-style {
      opacity: 0;
      transform: scale(0.95);
    }
  }

  .context-menu-item {
    display: flex;
    align-items: center;
    gap: var(--sp-2);
    width: 100%;
    padding: var(--sp-2) var(--sp-3);
    font-size: var(--text-sm);
    border-radius: var(--radius-sm);
    transition: background var(--duration-fast);
    text-align: left;

    &:hover { background: var(--bg-hover); }

    &.danger {
      color: var(--text-danger);

      &:hover { background: color-mix(in oklch, var(--text-danger) 8%, transparent); }
    }
  }

  .context-menu-sep {
    height: 1px;
    background: var(--border-subtle);
    margin: var(--sp-1) var(--sp-2);
  }

  /* Dropzone */
  .dropzone {
    position: fixed;
    inset: 0;
    z-index: var(--z-dropzone);
    background: var(--backdrop);
    display: flex;
    align-items: center;
    justify-content: center;
    animation: fade-in var(--duration-fast) ease;

    & .dropzone-inner {
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: var(--sp-3);
      padding: var(--sp-12);
      border: 2px dashed var(--accent);
      border-radius: var(--radius-xl);
      background: var(--bg-primary);
      color: var(--text-secondary);
      font-size: var(--text-md);
      font-weight: 500;

      & .icon { color: var(--accent); }
    }
  }

  /* Upload Panel */
  .upload-panel {
    position: fixed;
    bottom: var(--sp-4);
    left: var(--sp-4);
    width: 320px;
    max-height: 300px;
    background: color-mix(in oklch, var(--bg-primary) 85%, transparent);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    z-index: var(--z-upload-panel);
    animation: slide-up var(--duration-normal) var(--ease-out);
    display: flex;
    flex-direction: column;
  }

  .upload-panel-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--sp-3) var(--sp-4);
    border-bottom: 1px solid var(--border-subtle);
    font-size: var(--text-sm);
    font-weight: 500;
  }

  .upload-panel-body {
    padding: var(--sp-2) var(--sp-4);
    overflow-y: auto;
    flex: 1;
  }

  .upload-item { padding: var(--sp-2) 0; }

  .upload-item-name {
    font-size: var(--text-xs);
    color: var(--text-secondary);
    margin-bottom: var(--sp-1);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }

  .upload-progress {
    width: 100%;
    height: 4px;
    background: var(--bg-tertiary);
    border-radius: 2px;
    overflow: hidden;
  }

  .upload-progress-bar {
    height: 100%;
    background: var(--accent);
    border-radius: 2px;
    transition: width var(--duration-fast);
    width: 0%;

    &.indeterminate {
      width: 100%;
      background: linear-gradient(90deg, transparent, var(--accent), transparent);
      background-size: 200% 100%;
      animation: indeterminate 1.5s ease-in-out infinite;
    }

    &.done { background: #4caf50; width: 100%; }
    &.error { background: var(--text-danger); width: 100%; }
  }

  /* Preview Dialog */
  .preview-dialog[open] {
    width: min(800px, calc(100vw - 32px));
    height: min(600px, calc(100dvh - 64px));
    padding: 0;
    overflow: hidden;
  }

  .preview-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--sp-3) var(--sp-4);
    border-bottom: 1px solid var(--border-subtle);
    gap: var(--sp-2);
  }

  .preview-filename {
    font-size: var(--text-sm);
    font-weight: 500;
    min-width: 0;
  }

  .preview-body {
    flex: 1;
    overflow: auto;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--sp-4);
    min-height: 0;

    & img,
    & video,
    & audio {
      max-width: 100%;
      max-height: 100%;
      border-radius: var(--radius-sm);
    }

    & pre {
      width: 100%;
      max-height: 100%;
      overflow: auto;
      padding: var(--sp-4);
      font-family: var(--font-mono);
      font-size: var(--text-sm);
      background: var(--bg-secondary);
      border-radius: var(--radius-md);
      white-space: pre-wrap;
      word-break: break-all;
      align-self: flex-start;
    }
  }

  .preview-footer {
    padding: var(--sp-2) var(--sp-4);
    border-top: 1px solid var(--border-subtle);
    font-size: var(--text-xs);
    color: var(--text-tertiary);
    display: flex;
    gap: var(--sp-4);
    flex-wrap: wrap;
  }

  /* Skeleton */
  .skeleton-card {
    border-radius: var(--radius-lg);
    background: var(--bg-secondary);
    min-height: 100px;
    animation: skeleton-pulse 1.5s ease-in-out infinite;
  }

  /* Empty State */
  .empty-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--sp-3);
    padding: var(--sp-12) var(--sp-4);
    color: var(--text-tertiary);
    text-align: center;

    & p { font-size: var(--text-md); }
  }

  /* Load More */
  .load-more {
    display: flex;
    justify-content: center;
    padding: var(--sp-6) 0 var(--sp-2);
  }

  /* Paste hint — fixed bottom, subtle */
  .paste-hint {
    position: fixed;
    bottom: var(--sp-3);
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    align-items: center;
    gap: var(--sp-1);
    font-size: var(--text-xs);
    color: var(--text-tertiary);
    opacity: 0.5;
    transition: opacity var(--duration-normal);
    pointer-events: none;
    z-index: 1;

    &:hover { opacity: 0.8; }

    & kbd {
      display: inline-block;
      padding: 1px 5px;
      font-family: var(--font-mono);
      font-size: 10px;
      line-height: 1.4;
      color: var(--text-tertiary);
      background: var(--bg-secondary);
      border: 1px solid var(--border-subtle);
      border-radius: var(--radius-sm);
    }
  }

  /* Config Dialog Sections */
  .config-section {
    margin-bottom: var(--sp-4);
    padding-bottom: var(--sp-3);
    border-bottom: 1px solid var(--border-subtle);

    &:last-of-type { border-bottom: none; padding-bottom: 0; }

    & h3 {
      font-size: var(--text-sm);
      font-weight: 600;
      color: var(--text-tertiary);
      text-transform: uppercase;
      letter-spacing: 0.05em;
      margin-bottom: var(--sp-3);
    }
  }

  .field-row {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--sp-3);

    @media (width <= 480px) {
      grid-template-columns: 1fr;
    }
  }

  /* Toolbar Select */
  .toolbar-select {
    padding: var(--sp-1) var(--sp-2);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    background: var(--bg-primary);
    color: var(--text-secondary);
    font-size: var(--text-sm);
    cursor: pointer;
    transition: border-color var(--duration-fast);

    &:focus { outline: none; border-color: var(--accent); }
    &:hover { border-color: var(--text-tertiary); }
  }
}

/* --- Utilities --- */
@layer utilities {
  .sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0,0,0,0);
    white-space: nowrap;
    border: 0;
  }

  .truncate {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }

  .text-secondary { color: var(--text-secondary); }
  .flex { display: flex; }
  .items-center { align-items: center; }
}

/* --- Animations --- */
@layer animations {
  @keyframes fade-in {
    from { opacity: 0; }
    to { opacity: 1; }
  }

  @keyframes toast-in {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
  }

  @keyframes toast-out {
    from { opacity: 1; transform: translateY(0); }
    to { opacity: 0; transform: translateY(-8px); }
  }

  @keyframes skeleton-pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.4; }
  }

  @keyframes slide-up {
    from { opacity: 0; transform: translateY(16px); }
    to { opacity: 1; transform: translateY(0); }
  }

  @keyframes spin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
  }

  @keyframes indeterminate {
    0% { background-position: -200% 0; }
    100% { background-position: 200% 0; }
  }

  /* Staggered file card entrance */
  .file-card {
    animation: fade-in var(--duration-normal) var(--ease-out) both;

    &:nth-child(1) { animation-delay: 0ms; }
    &:nth-child(2) { animation-delay: 20ms; }
    &:nth-child(3) { animation-delay: 40ms; }
    &:nth-child(4) { animation-delay: 60ms; }
    &:nth-child(5) { animation-delay: 80ms; }
    &:nth-child(6) { animation-delay: 100ms; }
    &:nth-child(7) { animation-delay: 120ms; }
    &:nth-child(8) { animation-delay: 140ms; }
    &:nth-child(9) { animation-delay: 160ms; }
    &:nth-child(10) { animation-delay: 180ms; }
    &:nth-child(11) { animation-delay: 200ms; }
    &:nth-child(12) { animation-delay: 220ms; }
  }

  /* View Transition customization */
  ::view-transition-old(root),
  ::view-transition-new(root) {
    animation-duration: var(--duration-normal);
  }
}