:root {
      --bg: #081224;
      --bg2: #0d172b;
      --panel: #1b2738;
      --panel2: #101a2a;
      --border: #2e4057;
      --text: #e7edf6;
      --muted: #9bb0c8;
      --accent: #69a7ff;
      --light: #f0d9b5;
      --dark: #b58863;
      --move: rgba(255, 212, 59, 0.34);
      --select: rgba(95, 171, 255, 0.38);
      --legal: rgba(38, 211, 102, 0.26);
      --body-gradient: radial-gradient(circle at top, #10203a 0%, var(--bg) 42%, #050c18 100%);
      --surface: rgba(27, 39, 56, 0.9);
      --shadow: 0 18px 40px rgba(0,0,0,0.22);
      --button-start: #25344a;
      --button-end: #1b2738;
      --header-bg: #162235;
      --row-hover: rgba(105, 167, 255, 0.08);
      --row-active-start: rgba(49, 72, 104, 0.95);
      --row-active-end: rgba(36, 56, 82, 0.95);
      --variation-border: rgba(105,167,255,.45);
      --variation-bg: rgba(27, 46, 72, 0.42);
      --variation-text: #8fc1ff;
      --variation-text-hover: #bddbff;
    }
    body[data-theme="blue"] {
      --bg: #061726;
      --bg2: #0c2236;
      --panel: #15324b;
      --panel2: #0d263b;
      --border: #2b5d87;
      --text: #eaf7ff;
      --muted: #9fc8e4;
      --accent: #58c2ff;
      --light: #d8eef8;
      --dark: #6da8c4;
      --move: rgba(255, 224, 102, 0.32);
      --select: rgba(88, 194, 255, 0.30);
      --legal: rgba(73, 214, 172, 0.28);
      --body-gradient: radial-gradient(circle at top, #0f4161 0%, #0a2942 34%, #061726 100%);
      --surface: rgba(16, 44, 68, 0.9);
      --shadow: 0 18px 40px rgba(2, 18, 29, 0.34);
      --button-start: #1d4c70;
      --button-end: #13344d;
      --header-bg: #143554;
      --row-hover: rgba(88, 194, 255, 0.10);
      --row-active-start: rgba(33, 84, 122, 0.95);
      --row-active-end: rgba(23, 62, 92, 0.95);
      --variation-border: rgba(88,194,255,.46);
      --variation-bg: rgba(18, 62, 92, 0.46);
      --variation-text: #92ddff;
      --variation-text-hover: #d7f3ff;
    }
    * { box-sizing: border-box; }
    html, body { margin: 0; padding: 0; }
    html {
      scrollbar-gutter: stable;
    }
    body {
      min-height: 100vh;
      overflow-y: scroll;
      font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
      background: var(--body-gradient);
      color: var(--text);
    }
    .app {
      max-width: 1680px;
      margin: 0 auto;
      padding: 18px;
      display: grid;
      gap: 18px;
    }
    .topbar, .panel {
      background: var(--surface);
      border: 1px solid var(--border);
      border-radius: 20px;
      box-shadow: var(--shadow);
      backdrop-filter: blur(10px);
    }
    .topbar {
      position: relative;
      z-index: 30;
      padding: 18px 20px;
      display: flex;
      align-items: flex-start;
      justify-content: space-between;
      gap: 16px;
    }
    .topbar h1 { margin: 0; font-size: 28px; }
    .topbar p { margin: 4px 0 0; color: var(--muted); }
    .theme-switcher {
      position: relative;
      margin-left: auto;
      flex-shrink: 0;
    }
    .theme-toggle-btn {
      min-width: 148px;
      justify-content: center;
    }
    .theme-menu {
      position: absolute;
      top: calc(100% + 10px);
      right: 0;
      width: 180px;
      padding: 8px;
      display: grid;
      gap: 6px;
      background: var(--surface);
      border: 1px solid var(--border);
      border-radius: 16px;
      box-shadow: var(--shadow);
      backdrop-filter: blur(10px);
      z-index: 200;
    }
    .theme-menu[hidden] {
      display: none;
    }
    .theme-option {
      width: 100%;
      justify-content: flex-start;
    }
    .theme-option.active {
      border-color: var(--accent);
      background: linear-gradient(180deg, var(--row-active-start), var(--row-active-end));
    }
    .toolbar { display: none; }
    button, .action-link {
      border: 1px solid var(--border);
      background: linear-gradient(180deg, var(--button-start), var(--button-end));
      color: var(--text);
      border-radius: 14px;
      padding: 11px 16px;
      font-size: 15px;
      cursor: pointer;
      text-decoration: none;
      display: inline-flex;
      align-items: center;
      gap: 8px;
      transition: .18s ease;
    }
    button:hover, .action-link:hover { border-color: var(--accent); transform: translateY(-1px); }
    button:disabled { opacity: .45; cursor: not-allowed; transform: none; }
    .layout {
      display: grid;
      grid-template-columns: minmax(520px, 1.35fr) minmax(420px, 760px) 420px;
      gap: 18px;
      align-items: start;
    }
    .panel { padding: 18px; min-width: 0; }
    .panel h2 { margin: 0 0 14px; font-size: 18px; }
    .games-list {
      max-height: calc(100vh - 180px);
      overflow: auto;
      border: 1px solid var(--border);
      border-radius: 16px;
      background: var(--panel2);
    }
    .games-table {
      width: max-content;
      min-width: 100%;
      border-collapse: collapse;
      font-size: 13px;
    }
    .games-table th,
    .games-table td {
      padding: 10px 12px;
      border-bottom: 1px solid rgba(46, 64, 87, 0.82);
      vertical-align: top;
      white-space: nowrap;
    }
    .games-table th {
      position: sticky;
      top: 0;
      z-index: 1;
      background: var(--header-bg);
      color: var(--muted);
      font-size: 12px;
      text-transform: uppercase;
      letter-spacing: .03em;
    }
    .games-table tbody tr {
      cursor: pointer;
      transition: background .18s ease;
    }
    .games-table tbody tr:hover {
      background: var(--row-hover);
    }
    .games-table tbody tr.active {
      background: linear-gradient(180deg, var(--row-active-start), var(--row-active-end));
      box-shadow: inset 0 0 0 1px rgba(105,167,255,.24);
    }
    .games-table td.numeric {
      text-align: right;
      font-variant-numeric: tabular-nums;
    }
    .games-table th:first-child,
    .games-table td.index-cell {
      width: 30px;
      min-width: 30px;
      padding-left: 4px;
      padding-right: 1px;
      text-align: left;
    }
    .games-table th:nth-child(2),
    .games-table td:nth-child(2) {
      padding-left: 5px;
    }
    .games-table td.event-cell {
      white-space: normal;
      min-width: 240px;
      line-height: 1.35;
    }
    .games-table th:nth-child(4),
    .games-table td:nth-child(4) {
      padding-right: 3px;
    }
    .games-table th:nth-child(5),
    .games-table td:nth-child(5) {
      padding-left: 3px;
    }
    .table-sort-btn {
      appearance: none;
      -webkit-appearance: none;
      background: none;
      border: none;
      border-radius: 0;
      box-shadow: none;
      color: inherit;
      padding: 0;
      min-width: 0;
      font: inherit;
      letter-spacing: inherit;
      text-transform: inherit;
      cursor: pointer;
      transform: none;
    }
    .table-sort-btn:hover {
      color: var(--text);
      background: none;
      border: none;
      transform: none;
    }
    .table-sort-btn.active {
      color: #cfe3ff;
      font-weight: 700;
    }
    .subline, .meta-line, .small-note { color: var(--muted); font-size: 13px; }
    .subline { margin-top: 5px; }
    .board-col { display: grid; gap: 14px; }
    .board-shell {
      position: relative;
      width: min(100%, 700px, calc(100vh - 340px));
      max-width: 100%;
      margin: 0 auto;
      padding-right: 28px;
    }
    .board-head {
      display: grid;
      gap: 6px;
      min-height: 72px;
      align-content: start;
    }
    .board-title {
      font-size: 18px;
      font-weight: 700;
      line-height: 1.3;
      overflow-wrap: anywhere;
    }
    .board-subtitle { color: var(--muted); line-height: 1.45; }
    .board {
      width: 100%;
      max-width: 100%;
      aspect-ratio: 1 / 1;
      display: grid;
      grid-template-columns: repeat(8, 1fr);
      grid-template-rows: repeat(8, 1fr);
      border-radius: 22px;
      overflow: hidden;
      border: 1px solid var(--border);
      background: #20324c;
      touch-action: none;
      user-select: none;
      margin: 0 auto;
      align-self: start;
    }
    .board-resize-handle {
      position: absolute;
      right: 6px;
      bottom: -12px;
      width: 24px;
      height: 24px;
      min-width: 24px;
      padding: 0;
      border-radius: 999px;
      border: 1px solid rgba(105,167,255,.38);
      background: linear-gradient(180deg, #2a3c56, #1b2738);
      box-shadow: 0 8px 18px rgba(0,0,0,.24);
      cursor: nwse-resize;
      z-index: 3;
    }
    .board-resize-handle::before {
      content: "";
      width: 9px;
      height: 9px;
      border-right: 2px solid rgba(231,237,246,.88);
      border-bottom: 2px solid rgba(231,237,246,.88);
      transform: rotate(0deg);
      display: block;
      margin: 5px 0 0 5px;
    }
    .board-shell.resizing .board-resize-handle {
      border-color: var(--accent);
      box-shadow: 0 0 0 4px rgba(105,167,255,.14), 0 8px 18px rgba(0,0,0,.24);
    }
    .square {
      position: relative;
      display: flex;
      align-items: center;
      justify-content: center;
    }
    .square.light { background: var(--light); }
    .square.dark { background: var(--dark); }
    .square.last::before,
    .square.selected::before,
    .square.legal::after {
      content: "";
      position: absolute;
      inset: 0;
      pointer-events: none;
    }
    .square.last::before { background: var(--move); }
    .square.selected::before { background: var(--select); }
    .square.legal::after {
      inset: 28%;
      border-radius: 999px;
      background: var(--legal);
      box-shadow: inset 0 0 0 2px rgba(20,100,49,.18);
    }
    .coord {
      position: absolute;
      font-size: 11px;
      font-weight: 700;
      opacity: .85;
      pointer-events: none;
    }
    .coord.file { right: 5px; bottom: 4px; }
    .coord.rank { left: 5px; top: 4px; }
    .square.light .coord { color: rgba(105, 77, 48, 0.92); }
    .square.dark .coord { color: rgba(246, 230, 209, 0.95); }
    .piece {
      width: 84%;
      height: 84%;
      object-fit: contain;
      pointer-events: none;
      -webkit-user-drag: none;
      filter: drop-shadow(0 1px 1px rgba(0,0,0,.22));
    }
    .board-actions, .nav-actions {
      display: flex;
      gap: 10px;
      flex-wrap: wrap;
    }
    .status-grid {
      display: grid;
      grid-template-columns: repeat(2, minmax(0, 1fr));
      gap: 10px;
    }
    .status-card {
      background: var(--panel2);
      border: 1px solid var(--border);
      border-radius: 14px;
      padding: 10px 12px;
    }
    .status-card .label { color: var(--muted); font-size: 12px; margin-bottom: 4px; }
    .status-card .value { font-size: 14px; word-break: break-word; }
    .moves-col {
      display: grid;
      gap: 14px;
      align-content: start;
      min-width: 0;
    }
    .analysis-box {
      background: var(--panel2);
      border: 1px solid var(--border);
      border-radius: 16px;
      padding: 14px;
      display: grid;
      gap: 8px;
      align-content: start;
      min-width: 0;
    }
    .analysis-head {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 12px;
      flex-wrap: nowrap;
      min-width: 0;
    }
    .analysis-head > * {
      min-width: 0;
    }
    .analysis-line {
      font-size: 15px;
      min-width: 0;
      overflow-wrap: anywhere;
    }
    .analysis-controls {
      display: inline-flex;
      gap: 10px;
      align-items: center;
      flex-wrap: nowrap;
      justify-content: flex-end;
      flex: 0 0 auto;
      min-width: 0;
    }
    .analysis-mode-grid {
      display: grid;
      grid-template-columns: repeat(2, minmax(44px, auto));
      gap: 8px;
      align-items: center;
    }
    .analysis-lines-control {
      display: grid;
      gap: 4px;
      min-width: 140px;
    }
    .analysis-lines-label {
      color: var(--muted);
      font-size: 12px;
      line-height: 1.2;
    }
    .analysis-lines-row {
      display: grid;
      grid-template-columns: 96px auto;
      gap: 8px;
      align-items: center;
    }
    .analysis-mode-btn,
    .analysis-icon-btn {
      min-width: 44px;
      padding: 8px 10px;
      justify-content: center;
      font-size: 14px;
      line-height: 1;
    }
    .analysis-icon-btn {
      font-size: 16px;
      padding-top: 7px;
      padding-bottom: 7px;
    }
    .analysis-lines-range {
      width: 100%;
      accent-color: var(--accent);
    }
    .analysis-lines-value {
      min-width: 22px;
      text-align: center;
      font-size: 13px;
      color: var(--text);
    }
    .analysis-mode-btn.active {
      border-color: var(--accent);
      background: linear-gradient(180deg, var(--row-active-start), var(--row-active-end));
    }
    .pv-line {
      color: var(--muted);
      line-height: 1.5;
      font-size: 13px;
      min-height: calc(1.5em * 4);
      max-height: calc(1.5em * 4);
      overflow: auto;
      white-space: pre-line;
      scrollbar-gutter: stable;
      overflow-wrap: anywhere;
    }
    .moves-wrap {
      background: var(--panel2);
      border: 1px solid var(--border);
      border-radius: 16px;
      padding: 10px;
      max-height: calc(100vh - 360px);
      overflow: auto;
      scrollbar-gutter: stable;
      min-width: 0;
    }
    .move-row {
      display: grid;
      grid-template-columns: 34px 1fr 1fr;
      gap: 8px;
      margin-bottom: 8px;
      align-items: center;
    }
    .move-no { color: var(--muted); text-align: right; padding-right: 4px; }
    .move-btn {
      width: 100%;
      justify-content: flex-start;
      padding: 9px 12px;
      border-radius: 12px;
      font-weight: 600;
    }
    .move-btn.current {
      border-color: var(--accent);
      background: linear-gradient(180deg, #314868, #243852);
    }
    .variation-block {
      margin: -2px 0 10px 42px;
      padding: 10px 12px;
      border-left: 3px solid var(--variation-border);
      background: var(--variation-bg);
      border-radius: 10px;
      line-height: 1.9;
      font-size: 0;
    }
    .variation-group {
      display: inline;
      white-space: normal;
    }
    .variation-paren,
    .variation-prefix {
      color: var(--muted);
      font-size: 13px;
      font-weight: 700;
      margin-right: 6px;
    }
    .variation-paren {
      margin-right: 4px;
    }
    .variation-btn {
      appearance: none;
      -webkit-appearance: none;
      background: none;
      border: none;
      border-radius: 0;
      box-shadow: none;
      display: inline;
      padding: 0;
      min-width: 0;
      margin: 0 6px 0 0;
      vertical-align: baseline;
      font-size: 14px;
      font-weight: 600;
      color: var(--variation-text);
      cursor: pointer;
      transform: none;
      text-decoration: none;
    }
    .variation-btn:hover {
      color: var(--variation-text-hover);
      transform: none;
      border: none;
      background: none;
    }
    .variation-btn.current {
      color: #ffffff;
      text-decoration: underline;
      text-underline-offset: 2px;
    }

    .turn-dot {
      position: absolute;
      right: 4px;
      width: 16px;
      height: 16px;
      border-radius: 999px;
      border: 2px solid rgba(255,255,255,.28);
      box-shadow: 0 0 0 1px rgba(0,0,0,.18);
      opacity: .38;
      transition: .18s ease;
      z-index: 2;
      pointer-events: none;
    }
    .turn-dot.white { top: 10px; background: #f6f7fb; }
    .turn-dot.black { bottom: 10px; background: #11161f; }
    .turn-dot.active {
      opacity: 1;
      box-shadow: 0 0 0 1px rgba(0,0,0,.22), 0 0 12px rgba(255,255,255,.18);
      transform: scale(1.06);
    }
    .board-footer-actions {
      display: grid;
      grid-template-columns: auto auto auto auto;
      grid-template-areas:
        "prev flip fen next"
        ". download-game download-all .";
      gap: 10px;
      justify-content: center;
      align-items: center;
    }
    .board-footer-actions #prevGameBtn { grid-area: prev; }
    .board-footer-actions #flipBtn { grid-area: flip; }
    .board-footer-actions #copyFenBtn { grid-area: fen; }
    .board-footer-actions #downloadGameBtn { grid-area: download-game; }
    .board-footer-actions #downloadAllGamesBtn { grid-area: download-all; }
    .board-footer-actions #nextGameBtn { grid-area: next; }
    .board-footer-actions #prevGameBtn,
    .board-footer-actions #nextGameBtn {
      min-width: 46px;
      padding-left: 12px;
      padding-right: 12px;
      justify-content: center;
      font-size: 18px;
      line-height: 1;
    }
    .moves-controls {
      display: grid;
      grid-template-columns: 1fr auto 1fr;
      gap: 10px;
      align-items: center;
    }
    .moves-controls button {
      min-width: 46px;
      justify-content: center;
      padding: 11px 12px;
    }
    .moves-nav-group {
      grid-column: 2;
      display: flex;
      gap: 10px;
      justify-content: center;
    }
    .analysis-return-btn {
      grid-column: 3;
      justify-self: end;
      display: none;
      animation: pulseGlow 1.5s ease-in-out infinite;
    }
    .analysis-return-btn.visible { display: inline-flex; }
    @keyframes pulseGlow {
      0%, 100% { box-shadow: 0 0 0 rgba(105,167,255,0); }
      50% { box-shadow: 0 0 0 4px rgba(105,167,255,.14); }
    }
    .footer-note { color: var(--muted); font-size: 13px; line-height: 1.45; }
    .notice {
      color: var(--muted);
      background: var(--panel2);
      border: 1px dashed var(--border);
      border-radius: 14px;
      padding: 12px 14px;
      line-height: 1.45;
      font-size: 13px;
    }
    @media (max-width: 1420px) {
      .layout { grid-template-columns: minmax(440px, 1.2fr) minmax(380px, 1fr) 360px; }
    }
    @media (max-width: 1180px) {
      .layout { grid-template-columns: 1fr; }
      .games-list, .moves-wrap { max-height: none; }
    }
    @media (max-width: 640px) {
      .topbar {
        flex-direction: column;
        align-items: stretch;
      }
      .theme-switcher {
        margin-left: 0;
      }
      .theme-toggle-btn {
        width: 100%;
      }
      .theme-menu {
        left: 0;
        right: auto;
        width: 100%;
      }
      .board-footer-actions {
        grid-template-columns: repeat(2, minmax(0, 1fr));
        grid-template-areas:
          "prev next"
          "flip fen"
          "download-game download-all";
      }
    }