:root {
      /* Green Chalkboard Theme (Default) */
      --board-bg: #1e3b2b;
      --board-texture: radial-gradient(circle, rgba(255,255,255,0.05) 0%, rgba(0,0,0,0.3) 100%);
      --chalk-white: #f8f9fa;
      --chalk-yellow: #fff3a0;
      --chalk-green: #a8ffb2;
      --chalk-blue: #9ee2ff;
      --chalk-orange: #ffd09e;
      --chalk-pink: #ffb3d9;
      --chalk-purple: #e3bfff;
      --chalk-dim: rgba(248, 249, 250, 0.4);
      --wood-border: #5c3a21;
      --wood-inner: #3d2312;
      --font-chalk-heading: 'Fredericka the Great', cursive;
      --font-chalk-hand: 'Cabin Sketch', cursive;
      --font-chalk-sub: 'Patrick Hand', cursive;
    }

    [data-theme="dark"] {
      /* Black Chalkboard Theme */
      --board-bg: #17181c;
      --board-texture: radial-gradient(circle, rgba(255,255,255,0.03) 0%, rgba(0,0,0,0.5) 100%);
      --wood-border: #3a2213;
      --wood-inner: #241308;
    }

    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
      user-select: none;
    }

    body {
      background-color: #0b0d0e;
      background-image: repeating-linear-gradient(45deg, #111 0, #111 10px, #0b0d0e 10px, #0b0d0e 20px);
      color: var(--chalk-white);
      font-family: var(--font-chalk-sub);
      min-height: 100vh;
      display: flex;
      flex-direction: column;
      justify-content: center;
      align-items: center;
      padding: 1.5rem;
      overflow-x: hidden;
    }

    .board-frame {
      width: 100%;
      max-width: 900px;
      background: var(--wood-border);
      border: 6px solid var(--wood-inner);
      border-radius: 16px;
      padding: 18px;
      box-shadow: 0 20px 50px rgba(0, 0, 0, 0.7), inset 0 0 10px rgba(0, 0, 0, 0.8);
      position: relative;
    }

    .blackboard {
      background-color: var(--board-bg);
      background-image: var(--board-texture);
      border-radius: 8px;
      border: 3px dashed rgba(255, 255, 255, 0.15);
      padding: 2rem;
      box-shadow: inset 0 0 80px rgba(0, 0, 0, 0.6);
      position: relative;
      display: flex;
      flex-direction: column;
      gap: 1.5rem;
    }

    .blackboard::before {
      content: "";
      position: absolute;
      top: 0; left: 0; right: 0; bottom: 0;
      background: repeating-radial-gradient(circle at 50% 50%, rgba(255,255,255,0.02), rgba(255,255,255,0.02) 2px, transparent 2px, transparent 4px);
      pointer-events: none;
      opacity: 0.7;
    }

    header {
      display: flex;
      justify-content: space-between;
      align-items: center;
      border-bottom: 2px dashed var(--chalk-dim);
      padding-bottom: 1rem;
      position: relative;
      z-index: 2;
    }

    .brand {
      display: flex;
      align-items: center;
      gap: 0.75rem;
      font-family: var(--font-chalk-heading);
      font-size: 1.5rem;
      letter-spacing: 2px;
      text-decoration: none;
      color: var(--chalk-white);
      text-shadow: 2px 2px 0px rgba(0, 0, 0, 0.4);
    }

    .brand-icon {
      width: 16px;
      height: 16px;
      background-color: var(--chalk-orange);
      display: inline-block;
      transform: rotate(-8deg);
      box-shadow: 2px 2px 0px rgba(0,0,0,0.5);
    }

    .controls-right {
      display: flex;
      align-items: center;
      gap: 0.75rem;
    }

    .eraser-btn {
      background: #c29b68;
      border: 2px solid #5c3a21;
      border-bottom: 6px solid #3d2312;
      color: #2b1a0e;
      padding: 0.35rem 0.8rem;
      border-radius: 6px;
      cursor: pointer;
      font-family: var(--font-chalk-hand);
      font-size: 1rem;
      font-weight: 700;
      display: flex;
      align-items: center;
      gap: 0.4rem;
      box-shadow: 0 4px 10px rgba(0,0,0,0.4);
      transition: transform 0.1s ease;
    }

    .eraser-btn:active {
      transform: translateY(3px);
      border-bottom-width: 3px;
    }

    .chalk-link-btn {
      background: transparent;
      border: 2px solid var(--chalk-white);
      border-radius: 255px 15px 225px 15px/15px 225px 15px 255px;
      color: var(--chalk-white);
      padding: 0.35rem 0.8rem;
      font-family: var(--font-chalk-hand);
      font-size: 1.1rem;
      text-decoration: none;
      display: flex;
      align-items: center;
      gap: 0.4rem;
    }

    .chalk-link-btn:hover {
      color: var(--chalk-yellow);
      border-color: var(--chalk-yellow);
    }

    main {
      position: relative;
      z-index: 2;
      display: flex;
      flex-direction: column;
      gap: 1.25rem;
      width: 100%;
    }

    .mode-bar {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
      background: rgba(0, 0, 0, 0.2);
      padding: 0.75rem 1rem;
      border-radius: 255px 15px 225px 15px/15px 225px 15px 255px;
      border: 2px solid var(--chalk-dim);
      gap: 1rem;
      flex-wrap: wrap;
    }

    .mode-toggle {
      display: flex;
      gap: 0.5rem;
    }

    .toggle-btn {
      padding: 0.35rem 0.8rem;
      border: 2px solid var(--chalk-dim);
      background: transparent;
      color: var(--chalk-white);
      border-radius: 255px 15px 225px 15px/15px 225px 15px 255px;
      cursor: pointer;
      font-family: var(--font-chalk-hand);
      font-size: 1.1rem;
    }

    .toggle-btn.active {
      background: var(--chalk-orange);
      color: #17181c;
      border-color: var(--chalk-orange);
      font-weight: 700;
    }

    .room-actions {
      display: flex;
      gap: 0.5rem;
      align-items: center;
    }

    .room-input {
      padding: 0.35rem 0.6rem;
      border: 2px solid var(--chalk-white);
      border-radius: 6px;
      background: rgba(0,0,0,0.3);
      color: var(--chalk-green);
      font-family: var(--font-chalk-hand);
      font-size: 1.2rem;
      width: 100px;
      text-transform: uppercase;
      outline: none;
    }

    .peer-status-badge {
      font-family: var(--font-chalk-hand);
      font-size: 0.95rem;
      padding: 0.25rem 0.6rem;
      border-radius: 12px;
      border: 1px dashed var(--chalk-dim);
      color: var(--chalk-yellow);
      display: inline-flex;
      align-items: center;
      gap: 0.3rem;
    }

    .status-dot {
      width: 8px;
      height: 8px;
      border-radius: 50%;
      background: #ff4d4d;
      display: inline-block;
    }

    .status-dot.online {
      background: var(--chalk-green);
      box-shadow: 0 0 6px var(--chalk-green);
    }

    .host-crown {
      color: var(--chalk-yellow);
      margin-left: 0.2rem;
    }

    .scoreboard {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
      background: rgba(0, 0, 0, 0.25);
      padding: 0.75rem 1.25rem;
      border-radius: 8px;
      border: 2px dashed var(--chalk-dim);
      font-family: var(--font-chalk-hand);
      font-size: 1.3rem;
      color: var(--chalk-white);
    }

    .letter-display {
      font-family: var(--font-chalk-heading);
      font-size: 2rem;
      text-align: center;
      color: var(--chalk-yellow);
      text-shadow: 2px 2px 4px rgba(0,0,0,0.6);
    }

    .letter-display span {
      font-size: 3rem;
      color: var(--chalk-orange);
      text-transform: uppercase;
      margin-left: 0.5rem;
    }

    .timer-badge {
      font-family: var(--font-chalk-hand);
      font-size: 1.3rem;
      color: var(--chalk-pink);
    }

    .category-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 1.25rem;
      width: 100%;
    }

    @media (max-width: 600px) {
      .category-grid {
        grid-template-columns: 1fr;
      }
    }

    .category-field {
      display: flex;
      flex-direction: column;
      gap: 0.4rem;
      text-align: left;
    }

    .category-label {
      font-family: var(--font-chalk-hand);
      font-size: 1.3rem;
      color: var(--chalk-yellow);
      letter-spacing: 1px;
    }

    .category-input {
      width: 100%;
      padding: 0.6rem 0.9rem;
      border: 2px solid var(--chalk-white);
      border-radius: 255px 15px 225px 15px/15px 225px 15px 255px;
      background: rgba(0, 0, 0, 0.25);
      color: var(--chalk-green);
      font-family: var(--font-chalk-hand);
      font-size: 1.4rem;
      outline: none;
    }

    .category-input:focus {
      border-color: var(--chalk-orange);
      box-shadow: 0 0 8px var(--chalk-orange);
    }

    .submit-btn {
      grid-column: 1 / -1;
      width: 100%;
      padding: 0.85rem;
      background-color: var(--chalk-orange);
      color: #17181c;
      border: 2px solid var(--wood-inner);
      border-radius: 255px 15px 225px 15px/15px 225px 15px 255px;
      font-family: var(--font-chalk-hand);
      font-size: 1.6rem;
      font-weight: 700;
      cursor: pointer;
      margin-top: 0.5rem;
      box-shadow: 0 4px 10px rgba(0,0,0,0.5);
    }

    .submit-btn:hover {
      transform: scale(1.02);
      background-color: var(--chalk-yellow);
    }

    .modal-overlay {
      display: none;
      position: absolute;
      top: 0; left: 0; width: 100%; height: 100%;
      background: rgba(0, 0, 0, 0.75);
      backdrop-filter: blur(3px);
      border-radius: 8px;
      justify-content: center;
      align-items: center;
      z-index: 100;
      padding: 1rem;
    }

    .modal-card {
      background-color: var(--board-bg);
      border: 3px dashed var(--chalk-orange);
      border-radius: 12px;
      padding: 1.75rem;
      width: 100%;
      max-width: 450px;
      text-align: center;
      display: flex;
      flex-direction: column;
      gap: 1.1rem;
      box-shadow: 0 0 30px rgba(0,0,0,0.8);
      font-family: var(--font-chalk-sub);
    }

    .modal-card h2 {
      font-family: var(--font-chalk-heading);
      color: var(--chalk-yellow);
      font-size: 2rem;
    }

    .modal-btn {
      padding: 0.65rem 1rem;
      border-radius: 255px 15px 225px 15px/15px 225px 15px 255px;
      font-family: var(--font-chalk-hand);
      font-size: 1.3rem;
      font-weight: 700;
      cursor: pointer;
      border: 2px solid var(--chalk-white);
      background-color: var(--chalk-orange);
      color: #17181c;
    }

    .breakdown-table {
      width: 100%;
      border-collapse: collapse;
      font-family: var(--font-chalk-sub);
      font-size: 1.1rem;
      margin: 0.5rem 0;
    }

    .breakdown-table th, .breakdown-table td {
      border: 1px dashed var(--chalk-dim);
      padding: 0.5rem;
      text-align: left;
    }

    .breakdown-table th {
      color: var(--chalk-yellow);
      font-family: var(--font-chalk-hand);
      font-size: 1.2rem;
    }

    .share-box {
      background: rgba(0,0,0,0.3);
      border: 1px dashed var(--chalk-white);
      padding: 0.85rem;
      border-radius: 8px;
      font-family: var(--font-chalk-hand);
      font-size: 1.2rem;
      color: var(--chalk-green);
      word-break: break-all;
    }

    .toast {
      position: fixed;
      bottom: 25px;
      left: 50%;
      transform: translateX(-50%);
      background: #c29b68;
      color: #2b1a0e;
      border: 2px solid #5c3a21;
      padding: 0.6rem 1.4rem;
      border-radius: 20px;
      font-family: var(--font-chalk-hand);
      font-size: 1.2rem;
      font-weight: 700;
      box-shadow: 0 4px 15px rgba(0,0,0,0.6);
      display: none;
      z-index: 200;
    }

    .chalk-tray {
      height: 18px;
      background: #4a2e18;
      border-top: 3px solid #2b1a0e;
      border-radius: 0 0 8px 8px;
      position: relative;
      display: flex;
      align-items: center;
      padding: 0 20px;
      gap: 15px;
    }

    .chalk-piece {
      width: 35px;
      height: 8px;
      border-radius: 3px;
      box-shadow: 1px 2px 3px rgba(0,0,0,0.5);
    }