:root {
      --text-color: #333;
      --bg-color: #fff;
      --accent-color: #e74c3c;
      --light-bg: #f9f9f9;
      --border-color: #ddd;
    }

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

    .body-c {
      font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
      line-height: 1.6;
      color: var(--text-color);
      background-color: var(--bg-color);
      padding: 1rem;
    }

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

    h1 {
      font-size: 1.8rem;
      margin-bottom: 1.5rem;
      color: var(--accent-color);
      text-align: center;
    }

    h2 {
      font-size: 1.4rem;
      margin: 1.5rem 0 1rem;
      color: #2c3e50;
    }

    h3 {
      font-size: 1.2rem;
      margin: 1.25rem 0 0.75rem;
      color: #2c3e50;
    }

    p, ul, ol {
      margin-bottom: 1rem;
    }

    .instructions {
      background-color: var(--light-bg);
      padding: 1.25rem;
      border-radius: 8px;
      margin-bottom: 1.5rem;
      border-left: 4px solid var(--accent-color);
    }

    .exercise {
      margin-bottom: 1.5rem;
      padding: 1rem;
      border: 1px solid var(--border-color);
      border-radius: 6px;
      background-color: #fafafa;
    }

    .exercise-number {
      display: inline-block;
      width: 28px;
      height: 28px;
      background-color: var(--accent-color);
      color: white;
      text-align: center;
      line-height: 28px;
      border-radius: 50%;
      margin-right: 0.5rem;
      font-weight: bold;
    }

    .exercise-title {
      font-weight: bold;
      margin-bottom: 0.5rem;
    }

    .exercise-desc {
      margin-bottom: 0.5rem;
    }

    .exercise-tech {
      font-style: italic;
      color: #555;
    }

    .note {
      font-style: italic;
      color: var(--accent-color);
      margin-top: 0.5rem;
    }

    @media (max-width: 600px) {
      body {
        padding: 0.75rem;
      }

      h1 {
        font-size: 1.5rem;
      }

      h2 {
        font-size: 1.25rem;
      }

      .exercise-number {
        width: 24px;
        height: 24px;
        line-height: 24px;
        font-size: 0.9rem;
      }
    }
.header {
      text-align: center;
      margin-bottom: 2rem;
      padding: 1.5rem 0;
      border-bottom: 2px solid var(--accent);
    }

    .title-main {
      font-size: 2.2rem;
      font-weight: 900;
      color: var(--accent);
      text-transform: uppercase;
      letter-spacing: -0.5px;
      margin-bottom: 0.5rem;
      line-height: 1.1;
    }

    .subtitle {
      font-size: 1.4rem;
      font-weight: 700;
      margin-bottom: 1rem;
      color: #2c3e50;
    }

    .byline {
      font-style: italic;
      color: #666;
      margin-top: 1.5rem;
    }

    .intro {
      font-size: 1.1rem;
      margin-bottom: 1.5rem;
      background-color: var(--light);
      padding: 1.25rem;
      border-radius: 8px;
      border-left: 4px solid var(--accent);
    }

    .intro p {
      margin-bottom: 1rem;
    }

    .forward-run {
      font-style: italic;
      text-align: center;
      margin: 1.5rem 0;
      color: #777;
    }

    @media (max-width: 600px) {
      .title-main {
        font-size: 1.8rem;
      }
      .subtitle {
        font-size: 1.2rem;
      }
      body {
        padding: 0.75rem;
      }
      .exercise-number {
        width: 24px;
        height: 24px;
        font-size: 0.85rem;
      }
    }
 .tip-box {
      background-color: #e8f4f8;
      border-left: 4px solid #3498db;
      padding: 1rem;
      margin: 1.5rem 0;
      border-radius: 4px;
    }

    .tip-title {
      font-weight: bold;
      color: #2980b9;
      margin-bottom: 0.5rem;
    }