:root {
    /* dark (default) */
    --bg: #0d1117;
    --sidebar: #161b22;
    --panel: #1c2128;
    --panel-2: #22272e;
    --border: #30363d;
    --border-soft: #21262d;
    --text: #e6edf3;
    --subtext: #8b949e;
    --muted: #6e7681;
    --accent: #859f92;
    --accent-soft: rgba(133, 159, 146, 0.14);
    --accent-strong: #9bb5a8;
    --danger: #f85149;
    --gutter: #6e7681;
    --selection: rgba(133, 159, 146, 0.30);
    --shadow: 0 1px 0 rgba(255,255,255,0.02) inset, 0 0 0 1px var(--border);
  }

  [data-theme="light"] {
    --bg: #ffffff;
    --sidebar: #f6f8fa;
    --panel: #ffffff;
    --panel-2: #f6f8fa;
    --border: #d0d7de;
    --border-soft: #d8dee4;
    --text: #1f2328;
    --subtext: #59636e;
    --muted: #818b98;
    --accent: #5d7e6f;
    --accent-soft: rgba(93, 126, 111, 0.12);
    --accent-strong: #4d6c5e;
    --danger: #cf222e;
    --gutter: #afb8c1;
    --selection: rgba(93, 126, 111, 0.20);
  }

  * { box-sizing: border-box; }
  html, body {
    margin: 0; padding: 0; height: 100%;
    background: var(--bg);
    color: var(--text);
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    font-size: 13px;
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
  }
  ::selection { background: var(--selection); }

  /* ========== Layout ========== */
  .app {
    display: grid;
    grid-template-columns: 240px 1fr;
    height: 100vh;
    overflow: hidden;
  }

  /* ========== Sidebar ========== */
  .sidebar {
    background: var(--sidebar);
    border-right: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    overflow: hidden;
  }
  .brand {
    padding: 14px 16px;
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    gap: 10px;
  }
  .brand-link {
    display: flex;
    align-items: center;
    gap: 10px;
    color: inherit;
    text-decoration: none;
  }
  .brand-mark {
    width: 26px; height: 26px;
    border: 1px solid var(--border);
    background: var(--panel);
    border-radius: 4px;
    display: grid;
    place-items: center;
    font-family: 'JetBrains Mono', monospace;
    font-weight: 600;
    color: var(--accent);
    font-size: 12px;
  }
  .brand-name {
    font-weight: 600;
    font-size: 14px;
    letter-spacing: -0.01em;
  }
  .brand-name .accent { color: var(--accent); }
  .brand-tag {
    margin-left: auto;
    font-family: 'JetBrains Mono', monospace;
    font-size: 10px;
    color: var(--muted);
    border: 1px solid var(--border);
    border-radius: 3px;
    padding: 1px 5px;
  }

  .search {
    padding: 10px 12px;
    border-bottom: 1px solid var(--border);
    position: relative;
  }
  .search input {
    width: 100%;
    background: var(--bg);
    border: 1px solid var(--border);
    color: var(--text);
    border-radius: 4px;
    padding: 6px 10px 6px 28px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 12px;
    outline: none;
    transition: border-color .15s, box-shadow .15s;
  }
  [data-theme="light"] .search input { background: #fff; }
  .search input:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--accent-soft);
  }
  .search input::placeholder { color: var(--muted); }
  .search-icon {
    position: absolute;
    left: 21px; top: 50%;
    transform: translateY(-50%);
    color: var(--muted);
    pointer-events: none;
  }
  .search-kbd {
    position: absolute;
    right: 19px; top: 50%;
    transform: translateY(-50%);
    font-family: 'JetBrains Mono', monospace;
    font-size: 10px;
    color: var(--muted);
    border: 1px solid var(--border);
    border-radius: 3px;
    padding: 0 4px;
    background: var(--panel);
  }

  .nav {
    flex: 1;
    overflow-y: auto;
    padding: 6px 6px 16px;
  }
  .nav::-webkit-scrollbar { width: 8px; }
  .nav::-webkit-scrollbar-thumb { background: var(--border); border-radius: 4px; }
  .nav::-webkit-scrollbar-track { background: transparent; }

  .group { margin-top: 6px; }
  .group-header {
    width: 100%;
    text-align: left;
    background: transparent;
    border: 0;
    color: var(--subtext);
    padding: 8px 10px;
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    font-family: 'JetBrains Mono', monospace;
    font-size: 11px;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    border-radius: 4px;
  }
  .group-header:hover { color: var(--text); }
  .group-icon {
    font-size: 12px;
    width: 14px;
    display: inline-block;
    text-align: center;
    filter: grayscale(0.2);
  }
  .group-caret {
    margin-left: auto;
    transition: transform .15s ease;
    color: var(--muted);
    font-size: 10px;
  }
  .group.collapsed .group-caret { transform: rotate(-90deg); }
  .group.collapsed .group-list { display: none; }

  .group-list {
    list-style: none;
    margin: 2px 0 4px;
    padding: 0 0 0 6px;
    border-left: 1px dashed var(--border-soft);
    margin-left: 16px;
  }
  .tool-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    width: 100%;
    text-align: left;
    background: transparent;
    border: 0;
    color: var(--text);
    padding: 5px 10px;
    border-radius: 4px;
    cursor: pointer;
    font-size: 12.5px;
    font-family: inherit;
    border-left: 2px solid transparent;
    margin-left: -2px;
  }
  .tool-btn:hover { background: var(--panel); }
  .tool-btn.active {
    background: var(--accent-soft);
    color: var(--text);
    border-left-color: var(--accent);
    font-weight: 500;
  }
  .tool-btn .dot {
    width: 5px; height: 5px;
    border-radius: 50%;
    background: var(--muted);
    flex-shrink: 0;
  }
  .tool-btn.active .dot { background: var(--accent); box-shadow: 0 0 6px var(--accent); }
  .tool-btn .name { flex: 1; }
  .tool-btn .hint {
    font-family: 'JetBrains Mono', monospace;
    font-size: 9.5px;
    color: var(--muted);
    text-transform: uppercase;
    letter-spacing: 0.04em;
  }

  .sidebar-footer {
    border-top: 1px solid var(--border);
    padding: 10px 14px;
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--muted);
    font-family: 'JetBrains Mono', monospace;
    font-size: 10.5px;
  }

  /* ========== Ad slots ========== */
  .ad-slot {
    border: 1px dashed var(--border);
    background: repeating-linear-gradient(
      45deg,
      transparent 0,
      transparent 8px,
      var(--border-soft) 8px,
      var(--border-soft) 9px
    );
    color: var(--muted);
    font-family: 'JetBrains Mono', monospace;
    border-radius: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    gap: 2px;
    text-align: center;
    user-select: none;
  }
  .ad-slot .ad-tag {
    font-size: 9px;
    text-transform: uppercase;
    letter-spacing: 0.12em;
    color: var(--muted);
    opacity: 0.7;
  }
  .ad-slot .ad-size {
    font-size: 10.5px;
    color: var(--subtext);
  }
  .ad-slot .ad-label {
    font-size: 11px;
    color: var(--subtext);
  }
  .ad-slot .ad-note {
    font-size: 9.5px;
    color: var(--muted);
  }
  .ad-preview-slot {
    border-color: color-mix(in srgb, var(--accent) 45%, var(--border));
    background:
      linear-gradient(180deg, color-mix(in srgb, var(--accent) 8%, transparent), transparent),
      repeating-linear-gradient(
        45deg,
        transparent 0,
        transparent 8px,
        var(--border-soft) 8px,
        var(--border-soft) 9px
      );
  }
  .ad-preview-slot .ad-label {
    color: var(--accent-strong);
  }
  .adsense-slot {
    display: block;
    background: transparent;
    border-style: solid;
    overflow: hidden;
  }
  .adsense-slot .adsbygoogle {
    display: block;
    width: 100%;
    min-width: 1px;
    min-height: 90px;
  }
  .sidebar-ad {
    margin: 10px 12px;
    padding: 18px 8px;
    min-height: 90px;
  }
  .main-ad {
    margin-top: 18px;
    padding: 26px 16px;
    min-height: 92px;
    flex-shrink: 0;
  }
  .main-ad-wrap {
    border-top: 1px solid var(--border);
    padding: 14px 24px 18px;
    background: var(--bg);
    flex-shrink: 0;
  }
  .status-dot {
    width: 6px; height: 6px;
    border-radius: 50%;
    background: var(--accent);
    box-shadow: 0 0 8px var(--accent);
    animation: pulse 2s infinite;
  }
  @keyframes pulse { 50% { opacity: 0.4; } }

  /* ========== Main ========== */
  .main {
    display: flex;
    flex-direction: column;
    overflow: hidden;
    background: var(--bg);
    min-width: 0;
  }
  .topbar {
    height: 44px;
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    padding: 0 16px;
    gap: 14px;
    background: var(--bg);
    flex-shrink: 0;
  }
  .breadcrumb {
    font-family: 'JetBrains Mono', monospace;
    font-size: 12px;
    color: var(--subtext);
    display: flex;
    align-items: center;
    gap: 6px;
  }
  .breadcrumb .sep { color: var(--muted); }
  .breadcrumb .current { color: var(--text); }

  .topbar-actions {
    margin-left: auto;
    display: flex;
    align-items: center;
    gap: 6px;
  }
  .icon-btn {
    width: 28px; height: 28px;
    background: transparent;
    border: 1px solid transparent;
    border-radius: 4px;
    color: var(--subtext);
    cursor: pointer;
    display: grid; place-items: center;
    transition: all .15s;
  }
  .icon-btn:hover {
    background: var(--panel);
    color: var(--text);
    border-color: var(--border);
  }
  .icon-btn[aria-expanded="true"] {
    background: var(--panel);
    color: var(--text);
    border-color: var(--border);
  }

  .settings-menu {
    position: relative;
  }
  .settings-panel {
    position: absolute;
    top: calc(100% + 8px);
    right: 0;
    z-index: 30;
    width: 190px;
    padding: 10px;
    background: var(--panel);
    border: 1px solid var(--border);
    border-radius: 6px;
    box-shadow: 0 12px 28px rgba(0, 0, 0, .24);
  }
  .settings-panel[hidden] {
    display: none;
  }
  .settings-field {
    display: grid;
    gap: 6px;
    color: var(--subtext);
    font-size: 11px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0;
  }
  .settings-field select {
    width: 100%;
    height: 30px;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 4px;
    color: var(--text);
    font: inherit;
    text-transform: none;
    padding: 0 8px;
  }

  .theme-toggle {
    display: flex;
    align-items: center;
    background: var(--panel);
    border: 1px solid var(--border);
    border-radius: 4px;
    padding: 2px;
    gap: 0;
  }
  .theme-toggle button {
    background: transparent;
    border: 0;
    color: var(--subtext);
    cursor: pointer;
    padding: 3px 8px;
    border-radius: 3px;
    font-size: 11px;
    display: flex;
    align-items: center;
    gap: 4px;
    font-family: inherit;
  }
  .theme-toggle button.active {
    background: var(--bg);
    color: var(--text);
    box-shadow: 0 0 0 1px var(--border);
  }

  /* ========== Tool body ========== */
  .tool-body {
    flex: 1;
    overflow-y: auto;
    padding: 20px 24px 24px;
  }

  .tool-header {
    margin-bottom: 16px;
    display: flex;
    align-items: flex-start;
    gap: 14px;
  }
  .tool-icon {
    width: 38px; height: 38px;
    background: var(--panel);
    border: 1px solid var(--border);
    border-radius: 6px;
    display: grid; place-items: center;
    color: var(--accent);
    font-size: 18px;
    flex-shrink: 0;
  }
  .tool-title {
    font-size: 18px;
    font-weight: 600;
    letter-spacing: -0.01em;
    margin: 0 0 2px;
    color: var(--text);
    display: flex; align-items: center; gap: 8px;
  }
  .tool-tag {
    font-family: 'JetBrains Mono', monospace;
    font-size: 10px;
    color: var(--accent);
    background: var(--accent-soft);
    padding: 2px 6px;
    border-radius: 3px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    font-weight: 500;
  }
  .tool-desc {
    color: var(--subtext);
    font-size: 12.5px;
    margin: 0;
  }

  /* ========== Home ========== */
  .home-hero {
    display: grid;
    grid-template-columns: 58px minmax(0, 1fr);
    gap: 16px;
    align-items: start;
    margin-bottom: 22px;
    padding-bottom: 18px;
    border-bottom: 1px solid var(--border);
  }
  .home-mark {
    width: 58px;
    height: 58px;
    display: grid;
    place-items: center;
    border-radius: 8px;
    border: 1px solid var(--border);
    background: var(--panel);
    color: var(--accent);
    font-family: 'JetBrains Mono', monospace;
    font-size: 24px;
    font-weight: 700;
  }
  .home-hero h1,
  .home-section h2,
  .home-category h3,
  .tool-doc-section h2 {
    letter-spacing: 0;
  }
  .home-hero h1 {
    margin: 0 0 8px;
    color: var(--text);
    font-size: 26px;
    line-height: 1.15;
  }
  .home-hero p,
  .home-section p,
  .home-category p,
  .home-category li span {
    color: var(--subtext);
    line-height: 1.65;
  }
  .home-hero p,
  .home-section p {
    margin: 0;
    max-width: 860px;
    font-size: 14px;
  }
  .home-content {
    display: grid;
    gap: 22px;
  }
  .home-section h2 {
    margin: 0 0 10px;
    color: var(--text);
    font-size: 16px;
    font-weight: 650;
  }
  .home-category-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 12px;
  }
  .home-category {
    border: 1px solid var(--border);
    border-radius: 6px;
    background: var(--panel);
    padding: 14px;
  }
  .home-category-title {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 8px;
  }
  .home-category h3 {
    margin: 0;
    color: var(--text);
    font-size: 14px;
  }
  .home-category p {
    margin: 0 0 10px;
    font-size: 12.5px;
  }
  .home-category ul {
    list-style: none;
    margin: 0;
    padding: 0;
    display: grid;
    gap: 8px;
  }
  .home-category li {
    display: grid;
    gap: 2px;
  }
  .home-category a {
    color: var(--text);
    text-decoration: none;
    font-weight: 600;
    font-size: 13px;
  }
  .home-category a:hover {
    color: var(--accent);
  }
  .home-category li span {
    font-size: 12px;
  }

  /* Mode pill / options row */
  .options-row {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 12px;
    flex-wrap: wrap;
  }
  .seg {
    display: inline-flex;
    background: var(--panel);
    border: 1px solid var(--border);
    border-radius: 4px;
    padding: 2px;
  }
  .seg button {
    background: transparent;
    border: 0;
    color: var(--subtext);
    cursor: pointer;
    padding: 4px 12px;
    border-radius: 3px;
    font-size: 11.5px;
    font-family: 'JetBrains Mono', monospace;
    font-weight: 500;
  }
  .seg button.active {
    background: var(--accent-soft);
    color: var(--accent-strong);
  }
  [data-theme="light"] .seg button.active { color: var(--accent); }

  .opt-label {
    font-family: 'JetBrains Mono', monospace;
    font-size: 11px;
    color: var(--muted);
    text-transform: uppercase;
    letter-spacing: 0.06em;
  }
  .check-option {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    color: var(--subtext);
    cursor: pointer;
    font-family: 'JetBrains Mono', monospace;
    font-size: 11.5px;
  }
  .check-option input {
    accent-color: var(--accent);
  }

  /* ========== Editor panes ========== */
  .panes {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 14px;
    min-height: 0;
  }
  .panes.stacked { grid-template-columns: 1fr; grid-template-rows: 1fr 1fr; }

  .pane {
    background: var(--panel);
    border: 1px solid var(--border);
    border-radius: 6px;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    min-width: 0;
  }
  .pane-header {
    height: 32px;
    background: var(--panel-2);
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    padding: 0 10px;
    gap: 8px;
    flex-shrink: 0;
  }
  .pane-title {
    font-family: 'JetBrains Mono', monospace;
    font-size: 11px;
    color: var(--subtext);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    font-weight: 500;
  }
  .pane-title .role {
    color: var(--accent);
    margin-right: 6px;
  }
  .pane-meta {
    margin-left: auto;
    font-family: 'JetBrains Mono', monospace;
    font-size: 10.5px;
    color: var(--muted);
    display: flex;
    gap: 10px;
  }
  .pane-meta span b {
    color: var(--subtext);
    font-weight: 500;
  }

  .pane-toolbar {
    display: flex;
    gap: 4px;
    margin-left: 8px;
  }
  .pane-toolbar .icon-btn { width: 22px; height: 22px; font-size: 11px; }

  /* Editor (textarea + line numbers) */
  .editor {
    position: relative;
    flex: 1;
    display: flex;
    overflow: hidden;
    min-height: 240px;
  }
  .gutter {
    background: var(--panel);
    border-right: 1px solid var(--border-soft);
    color: var(--gutter);
    font-family: 'JetBrains Mono', 'Fira Code', monospace;
    font-size: 12.5px;
    line-height: 1.55;
    padding: 10px 8px 10px 10px;
    text-align: right;
    user-select: none;
    overflow: hidden;
    min-width: 38px;
    white-space: pre;
  }
  .editor textarea {
    flex: 1;
    background: var(--panel);
    border: 0;
    outline: 0;
    resize: none;
    color: var(--text);
    font-family: 'JetBrains Mono', 'Fira Code', monospace;
    font-size: 12.5px;
    line-height: 1.55;
    padding: 10px 12px;
    tab-size: 2;
    white-space: pre;
    overflow: auto;
    caret-color: var(--accent);
  }
  .editor textarea::placeholder { color: var(--muted); }
  .editor textarea[readonly] {
    background: var(--panel);
    cursor: text;
  }
  .editor textarea::-webkit-scrollbar,
  .gutter::-webkit-scrollbar { width: 10px; height: 10px; }
  .editor textarea::-webkit-scrollbar-thumb { background: var(--border); border-radius: 4px; }
  .editor textarea::-webkit-scrollbar-track { background: transparent; }

  .pane-footer {
    border-top: 1px solid var(--border-soft);
    background: var(--panel-2);
    padding: 6px 10px;
    display: flex;
    align-items: center;
    gap: 6px;
    flex-shrink: 0;
    font-family: 'JetBrains Mono', monospace;
    font-size: 10.5px;
    color: var(--muted);
    min-height: 30px;
  }
  .pane-footer .err { color: var(--danger); }
  .pane-footer .ok { color: var(--accent); }

  .diff-view {
    max-height: 420px;
    overflow: auto;
    background: var(--panel);
    font-family: 'JetBrains Mono', monospace;
    font-size: 12px;
    line-height: 1.55;
  }
  .diff-line {
    display: grid;
    grid-template-columns: 22px 42px minmax(0, 1fr);
    gap: 8px;
    padding: 3px 10px;
    border-bottom: 1px solid var(--border-soft);
    min-width: 0;
  }
  .diff-mark,
  .diff-no {
    color: var(--muted);
    user-select: none;
  }
  .diff-text {
    white-space: pre-wrap;
    overflow-wrap: anywhere;
  }
  .diff-add {
    background: rgba(68, 179, 127, .10);
  }
  .diff-add .diff-mark {
    color: var(--accent);
  }
  .diff-del {
    background: rgba(255, 107, 107, .10);
  }
  .diff-del .diff-mark {
    color: var(--danger);
  }

  /* ========== Action bar ========== */
  .actions {
    margin-top: 14px;
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
  }
  .btn {
    background: var(--panel);
    border: 1px solid var(--border);
    color: var(--text);
    padding: 7px 14px;
    border-radius: 4px;
    font-size: 12px;
    font-family: 'JetBrains Mono', monospace;
    font-weight: 500;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 6px;
    transition: all .12s;
  }
  .btn:hover {
    border-color: var(--accent);
    color: var(--text);
  }
  .btn:active { transform: translateY(1px); }
  .btn.primary {
    background: var(--accent);
    border-color: var(--accent);
    color: #0d1117;
  }
  .btn.primary:hover {
    background: var(--accent-strong);
    border-color: var(--accent-strong);
  }
  [data-theme="light"] .btn.primary { color: #fff; }
  .btn.ghost { background: transparent; }
  .btn .kbd {
    color: var(--muted);
    font-size: 10px;
    border: 1px solid var(--border);
    border-radius: 2px;
    padding: 0 4px;
    margin-left: 4px;
  }
  .btn.primary .kbd { color: rgba(13,17,23,0.6); border-color: rgba(13,17,23,0.3); }

  .actions-spacer { flex: 1; }
  .actions-meta {
    font-family: 'JetBrains Mono', monospace;
    font-size: 10.5px;
    color: var(--muted);
  }
  .actions-meta b { color: var(--accent); font-weight: 500; }

  /* Toast */
  .toast {
    position: fixed;
    bottom: 20px; left: 50%;
    transform: translateX(-50%) translateY(20px);
    background: var(--panel);
    border: 1px solid var(--accent);
    color: var(--text);
    padding: 8px 14px;
    border-radius: 4px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 12px;
    box-shadow: 0 8px 24px rgba(0,0,0,0.4);
    opacity: 0;
    pointer-events: none;
    transition: all .2s ease;
    z-index: 100;
    display: flex;
    align-items: center;
    gap: 8px;
  }
  .toast.show {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
  }
  .toast .check { color: var(--accent); }

  /* hash output grid */
  .hash-grid {
    display: grid;
    grid-template-columns: 110px 1fr auto;
    gap: 0;
    font-family: 'JetBrains Mono', monospace;
    font-size: 12.5px;
  }
  .hash-row {
    display: contents;
  }
  .hash-row > div {
    padding: 10px 12px;
    border-bottom: 1px solid var(--border-soft);
  }
  .hash-row:last-child > div { border-bottom: 0; }
  .hash-label { color: var(--accent); font-weight: 500; }
  .hash-value {
    color: var(--text);
    word-break: break-all;
    user-select: all;
  }
  .hash-value.empty { color: var(--muted); font-style: italic; }
  .hash-copy {
    color: var(--muted);
    cursor: pointer;
    display: grid; place-items: center;
    padding: 0 12px !important;
    border-bottom: 1px solid var(--border-soft);
  }
  .hash-copy:hover { color: var(--accent); }

  /* Inspector grid (string inspector) */
  .inspector {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1px;
    background: var(--border-soft);
    margin: 0;
  }
  .inspector .stat {
    background: var(--panel);
    padding: 14px 14px;
  }
  .inspector .stat-label {
    font-family: 'JetBrains Mono', monospace;
    font-size: 10.5px;
    color: var(--muted);
    text-transform: uppercase;
    letter-spacing: 0.06em;
    margin-bottom: 4px;
  }
  .inspector .stat-value {
    font-family: 'JetBrains Mono', monospace;
    font-size: 18px;
    color: var(--text);
    font-weight: 500;
  }
  .inspector .stat-value .unit { color: var(--muted); font-size: 11px; margin-left: 3px; }

  /* Case converter button grid in output */
  .case-grid {
    padding: 4px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1px;
    background: var(--border-soft);
  }
  .case-row {
    background: var(--panel);
    padding: 10px 12px;
    display: flex;
    align-items: flex-start;
    gap: 10px;
    cursor: pointer;
    min-width: 0;
  }
  .case-row:hover { background: var(--panel-2); }
  .case-row .case-label {
    font-family: 'JetBrains Mono', monospace;
    font-size: 10.5px;
    color: var(--muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    width: 90px;
    flex-shrink: 0;
  }
  .case-row .case-val {
    font-family: 'JetBrains Mono', monospace;
    font-size: 12.5px;
    color: var(--text);
    flex: 1;
    min-width: 0;
    white-space: pre-wrap;
    overflow-wrap: anywhere;
    word-break: break-word;
  }
  .case-row .case-val.empty { color: var(--muted); }
  .case-row-single {
    grid-column: 1 / -1;
    min-height: 160px;
    cursor: text;
  }
  .case-row-single .case-val {
    font-size: 13px;
    line-height: 1.7;
    width: 100%;
    user-select: text;
  }

  /* Timestamp tool layout */
  .ts-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 14px;
  }
  .ts-card {
    background: var(--panel);
    border: 1px solid var(--border);
    border-radius: 6px;
    overflow: hidden;
  }
  .ts-card-header {
    background: var(--panel-2);
    border-bottom: 1px solid var(--border);
    padding: 8px 12px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 11px;
    text-transform: uppercase;
    color: var(--subtext);
    letter-spacing: 0.06em;
  }

  .tool-doc {
    margin: 28px 0 0;
    border: 1px solid var(--border);
    background: var(--panel);
    border-radius: 6px;
    overflow: hidden;
    width: 100%;
  }
  .tool-doc-heading {
    background: var(--panel-2);
    color: var(--text);
    padding: 12px 14px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 11px;
    text-transform: uppercase;
    letter-spacing: 0.06em;
  }
  .tool-doc-body {
    padding: 16px 18px;
    color: var(--subtext);
    font-size: 13px;
    line-height: 1.7;
    border-top: 1px solid var(--border);
    display: grid;
    gap: 16px;
  }
  .tool-doc-section h2 {
    margin: 0 0 6px;
    color: var(--text);
    font-size: 13px;
    font-weight: 650;
  }
  .tool-doc-body p {
    margin: 0;
  }
  .ts-card-body {
    padding: 14px 12px;
  }
  .ts-input {
    width: 100%;
    background: var(--bg);
    border: 1px solid var(--border);
    color: var(--text);
    padding: 8px 10px;
    border-radius: 4px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 13px;
    outline: none;
  }
  [data-theme="light"] .ts-input { background: #fff; }
  .ts-input:focus { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
  .ts-output {
    margin-top: 10px;
    display: grid;
    grid-template-columns: 90px 1fr;
    gap: 6px 12px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 12px;
  }
  .ts-output .k { color: var(--muted); text-transform: uppercase; font-size: 10.5px; letter-spacing: 0.05em; padding-top: 2px;}
  .ts-output .v { color: var(--text); user-select: all; }
  .ts-now {
    margin-top: 12px;
    padding: 10px;
    background: var(--panel-2);
    border: 1px dashed var(--border);
    border-radius: 4px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 11.5px;
    color: var(--subtext);
    display: flex;
    justify-content: space-between;
    align-items: center;
  }
  .ts-now b { color: var(--accent); font-weight: 500; }

  /* responsive collapse */
  @media (max-width: 880px) {
    .app {
      grid-template-columns: 1fr;
      grid-template-rows: auto 1fr;
    }
    .sidebar {
      max-height: 260px;
      border-right: 0;
      border-bottom: 1px solid var(--border);
    }
    .brand {
      padding: 10px 14px;
    }
    .search {
      padding: 8px 12px;
    }
    .nav {
      min-height: 110px;
      padding-bottom: 8px;
    }
    .sidebar-ad,
    .sidebar-footer {
      display: none;
    }
    .topbar {
      min-height: 44px;
      height: auto;
      padding: 8px 12px;
      align-items: flex-start;
    }
    .breadcrumb {
      min-width: 0;
      flex: 1;
      flex-wrap: wrap;
    }
    .topbar-actions {
      flex-shrink: 0;
    }
    .tool-body {
      padding: 16px 14px 18px;
    }
    .tool-doc {
      margin-top: 22px;
    }
    .tool-doc-body {
      padding: 14px;
    }
    .home-hero {
      grid-template-columns: 1fr;
    }
    .home-mark {
      width: 48px;
      height: 48px;
      font-size: 20px;
    }
    .tool-title {
      flex-wrap: wrap;
    }
    .panes { grid-template-columns: 1fr; }
    .editor { min-height: 180px; }
    .ts-grid { grid-template-columns: 1fr; }
    .inspector { grid-template-columns: repeat(2, 1fr); }
  }