:root {
      --bg: #0f172a;
      --panel: #111827;
      --border: #1f2937;
      --text: #e5e7eb;
      --muted: #94a3b8;
      --accent: #f97316;
    }

    * {
      box-sizing: border-box;
    }

    body {
      margin: 0;
      font-family: Arial, sans-serif;
      background: linear-gradient(180deg, #0b1220 0%, var(--bg) 100%);
      color: var(--text);
      line-height: 1.7;
    }

    .container {
      max-width: 980px;
      margin: 0 auto;
      padding: 32px 20px 56px;
    }

    .card {
      background: var(--panel);
      border: 1px solid var(--border);
      border-radius: 18px;
      padding: 32px;
      box-shadow: 0 20px 40px rgba(0, 0, 0, 0.18);
    }

    .topbar {
      display: flex;
      justify-content: space-between;
      align-items: center;
      gap: 16px;
      flex-wrap: wrap;
      margin-bottom: 24px;
    }

    .brand {
      font-size: 24px;
      font-weight: 700;
      color: #fff;
    }

    .nav {
      display: flex;
      gap: 12px;
      flex-wrap: wrap;
    }

    .nav a {
      color: var(--accent);
      text-decoration: none;
      font-weight: 600;
    }

    h1, h2 {
      color: #fff;
      margin-top: 0;
    }

    h2 {
      margin-top: 28px;
      font-size: 20px;
    }

    p, li {
      color: var(--text);
    }

    .muted {
      color: var(--muted);
    }

    ul {
      padding-left: 20px;
    }

    @media (max-width: 560px) {
      .container {
        padding: 20px 14px 32px;
      }

      .card {
        border-radius: 16px;
        padding: 20px 16px;
      }

      .topbar {
        margin-bottom: 18px;
      }

      .brand {
        font-size: 20px;
      }

      .nav {
        gap: 8px 10px;
      }

      .nav a {
        font-size: 14px;
      }

      h1 {
        font-size: 28px;
      }

      h2 {
        font-size: 18px;
        margin-top: 24px;
      }

      p,
      li {
        font-size: 15px;
        line-height: 1.65;
      }
    }