:root {
      --bg: #0f172a;
      --card-bg: #1e293b;
      --card-border: #334155;
      --text-main: #f8fafc;
      --text-muted: #94a3b8;
      --primary: #2563eb;
      --primary-hover: #1d4ed8;
      --accent: #38bdf8;
      --success: #22c55e;
      --danger: #ef4444;
    }

    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      background-color: var(--bg);
      color: var(--text-main);
      padding: 24px 16px;
      line-height: 1.5;
    }

    .container {
      max-width: 840px;
      margin: 0 auto;
    }

    .header {
      display: flex;
      align-items: center;
      justify-content: space-between;
      margin-bottom: 24px;
      border-bottom: 1px solid var(--card-border);
      padding-bottom: 16px;
    }
    .brand-title {
      font-size: 20px;
      font-weight: 800;
      letter-spacing: 0.05em;
    }
    .brand-sub {
      font-size: 12px;
      color: var(--text-muted);
    }

    .card {
      background: var(--card-bg);
      border: 1px solid var(--card-border);
      border-radius: 12px;
      padding: 20px;
      margin-bottom: 24px;
    }

    .form-row {
      display: flex;
      gap: 10px;
      margin-top: 12px;
    }

    input[type="text"] {
      background: #0f172a;
      border: 1px solid var(--card-border);
      color: #fff;
      padding: 10px 14px;
      border-radius: 8px;
      font-size: 14px;
      flex: 1;
      outline: none;
    }
    input[type="text"]:focus { border-color: var(--accent); }

    .btn {
      padding: 10px 16px;
      border-radius: 8px;
      border: none;
      font-size: 13px;
      font-weight: 700;
      cursor: pointer;
      text-decoration: none;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      white-space: nowrap;
      transition: background-color 0.2s ease;
    }
    .btn-primary { background: var(--primary); color: #fff; }
    .btn-primary:hover { background: var(--primary-hover); }
    .btn-secondary { background: #334155; color: #fff; }
    .btn-secondary:hover { background: #475569; }
    .btn-copy { background: #0f766e; color: #fff; }
    .btn-copy:hover { background: #115e59; }
    .btn:disabled { opacity: 0.5; cursor: not-allowed; }

    .tournament-item {
      background: #0f172a;
      border: 1px solid var(--card-border);
      border-radius: 10px;
      padding: 16px;
      margin-bottom: 12px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      gap: 12px;
    }
    @media (max-width: 680px) {
      .tournament-item {
        flex-direction: column;
        align-items: flex-start;
      }
    }

    .t-title { font-size: 16px; font-weight: 800; }
    .t-meta { font-size: 12px; color: var(--text-muted); margin-top: 4px; }
    .actions { display: flex; gap: 8px; flex-wrap: wrap; }