:root {
      --bg: #0d121f;
      --card-bg: #151d2a;
      --card-inner: #1c2738;
      --text: #e2e8f0;
      --text-muted: #8b9bb4;
      --border: #2a374e;
      --primary: #3b82f6;
      --primary-hover: #2563eb;
      --accent: #8b5cf6;
      --success: #10b981;
      --success-bg: rgba(16, 185, 129, 0.15);
      --success-border: #10b981;
      --error: #ef4444;
      --error-bg: rgba(239, 68, 68, 0.18);
      --error-border: #ef4444;
      --warning: #f59e0b;
    }

    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    body {
      background-color: var(--bg);
      color: var(--text);
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
      line-height: 1.5;
      padding: 24px 16px;
    }

    .wrap {
      max-width: 800px;
      margin: 0 auto;
    }

    header {
      display: flex;
      justify-content: space-between;
      align-items: center;
      margin-bottom: 24px;
    }

    h1 {
      font-size: 22px;
      font-weight: 600;
      color: var(--text);
    }

    nav {
      display: flex;
      gap: 8px;
      margin-bottom: 20px;
    }

    button,
    .btn {
      font: inherit;
      border: 1px solid var(--border);
      background: var(--card-bg);
      color: var(--text);
      padding: 8px 16px;
      border-radius: 6px;
      cursor: pointer;
      transition: all 0.2s ease;
    }

    button:hover {
      background: var(--card-inner);
      border-color: var(--primary);
    }

    button.active,
    button.primary {
      background: var(--primary);
      color: #ffffff;
      border-color: var(--primary);
    }

    button.primary:hover {
      background: var(--primary-hover);
    }

    button:disabled {
      opacity: 0.5;
      cursor: not-allowed;
    }

    .card {
      background: var(--card-bg);
      border: 1px solid var(--border);
      border-radius: 10px;
      padding: 20px;
      margin-bottom: 16px;
    }

    .muted {
      color: var(--text-muted);
      font-size: 14px;
    }

    .row {
      display: flex;
      gap: 10px;
      flex-wrap: wrap;
      align-items: center;
    }

    .big-text {
      font-size: 26px;
      font-weight: 600;
      text-align: center;
      padding: 32px 12px;
      word-break: break-word;
    }

    .flashcard {
      cursor: pointer;
      min-height: 160px;
      display: flex;
      align-items: center;
      justify-content: center;
      flex-direction: column;
      user-select: none;
      background: var(--card-inner);
      border: 1px solid var(--border);
      border-radius: 8px;
    }

    .option-btn {
      display: block;
      width: 100%;
      text-align: left;
      margin-bottom: 10px;
      padding: 12px 16px;
      background: var(--card-inner);
      border: 1px solid var(--border);
      border-radius: 8px;
      color: var(--text);
    }

    .option-btn.correct {
      background: var(--success-bg);
      border-color: var(--success-border);
      color: #34d399;
    }

    .option-btn.wrong {
      background: var(--error-bg);
      border-color: var(--error-border);
      color: #fca5a5;
    }

    input[type="text"],
    textarea,
    select {
      font: inherit;
      width: 100%;
      padding: 10px 14px;
      border: 1px solid var(--border);
      border-radius: 6px;
      background: var(--card-inner);
      color: var(--text);
    }

    textarea {
      min-height: 110px;
      resize: vertical;
    }

    .progress-bar {
      height: 6px;
      background: var(--card-inner);
      border-radius: 3px;
      overflow: hidden;
      margin-bottom: 16px;
    }

    .progress-bar span {
      display: block;
      height: 100%;
      background: var(--primary);
      transition: width 0.3s ease;
    }

    .table-container {
      overflow-x: auto;
      margin-top: 12px;
    }

    table {
      width: 100%;
      border-collapse: collapse;
      font-size: 14px;
    }

    th,
    td {
      text-align: left;
      padding: 10px 12px;
      border-bottom: 1px solid var(--border);
    }

    th {
      color: var(--text-muted);
      font-weight: 600;
    }

    .feedback {
      padding: 14px;
      border-radius: 8px;
      margin: 12px 0;
      font-weight: 500;
    }

    .feedback.correct {
      background: var(--success-bg);
      border: 1px solid var(--success-border);
      color: #34d399;
    }

    .feedback.wrong {
      background: var(--error-bg);
      border: 1px solid var(--error-border);
      color: #fca5a5;
    }

    .tag {
      font-size: 11px;
      padding: 2px 6px;
      border-radius: 4px;
      background: var(--card-inner);
      border: 1px solid var(--border);
      color: var(--text-muted);
      margin-left: 6px;
    }

    .dropdown-multiselect {
      position: relative;
      display: inline-block;
    }

    .dropdown-toggle {
      background: var(--card-inner);
      border: 1px solid var(--border);
      padding: 8px 12px;
      border-radius: 6px;
      cursor: pointer;
      color: var(--text);
      font: inherit;
      display: inline-flex;
      align-items: center;
      justify-content: space-between;
      min-width: 140px;
    }

    .dropdown-content {
      display: none;
      position: absolute;
      background: var(--card-inner);
      border: 1px solid var(--border);
      border-radius: 6px;
      padding: 10px;
      z-index: 10;
      min-width: 160px;
      max-height: 200px;
      overflow-y: auto;
      margin-top: 4px;
      box-shadow: 0 4px 6px rgba(0, 0, 0, 0.3);
    }

    .dropdown-content.show {
      display: block;
    }

    .dropdown-content label {
      display: flex;
      align-items: center;
      gap: 8px;
      padding: 4px 0;
      cursor: pointer;
      font-size: 14px;
    }

    .table-controls {
      display: flex;
      gap: 10px;
      flex-wrap: wrap;
      margin-bottom: 12px;
      align-items: center;
    }

    .pagination-bar {
      display: flex;
      gap: 6px;
      align-items: center;
      margin-top: 14px;
      justify-content: space-between;
      flex-wrap: wrap;
    }