.header-banner {
            display: flex;
            background: #000;
            color: white;
            overflow: hidden;
            border-radius: 8px;
            box-shadow: 0 4px 12px rgba(0,0,0,0.1);
            margin: 20px auto;
            max-width: 900px;
        }

        .left-panel {
            flex: 1;
            padding: 40px 20px;
            background: #000;
            display: flex;
            align-items: center;
            justify-content: center;
            text-align: center;
        }

        .left-panel h1 {
            font-size: 5rem;
            font-weight: bold;
            letter-spacing: -2px;
            text-transform: uppercase;
            line-height: 0.9;
            margin: 0;
        }

        .right-panel {
            flex: 1;
            padding: 30px;
            background: #fff;
            color: #333;
            display: flex;
            flex-direction: column;
            justify-content: center;
        }

        .right-panel p {
            font-size: 18px;
            color: #d32f2f;
            margin-bottom: 20px;
            font-weight: bold;
        }

        .right-panel .credits {
            font-size: 14px;
            color: #555;
            text-transform: uppercase;
            letter-spacing: 1px;
            font-weight: bold;
        }

        /* Адаптивность */
        @media (max-width: 768px) {
            .header-banner {
                flex-direction: column;
                border-radius: 0;
            }

            .left-panel {
                padding: 30px 20px;
            }

            .left-panel h1 {
                font-size: 3rem;
                letter-spacing: -1px;
            }

            .right-panel {
                padding: 20px;
            }

            .right-panel p {
                font-size: 16px;
            }
        }
.header {
      text-align: center;
      margin-bottom: 30px;
      padding-bottom: 20px;
      border-bottom: 2px solid #eee;
    }

    .header h1 {
      font-size: 32px;
      color: #d32f2f;
      margin-bottom: 10px;
      text-transform: uppercase;
      letter-spacing: 1px;
    }

    .header p.subtitle {
      font-size: 18px;
      color: #555;
      font-style: italic;
    }

    .intro {
      background: #f0f4f8;
      padding: 20px;
      border-radius: 8px;
      margin-bottom: 30px;
      border-left: 4px solid #1976d2;
    }

    .intro h2 {
      margin-bottom: 12px;
      color: #1976d2;
    }

    .intro p {
      margin: 10px 0;
    }

    .instructions {
      background: #fff8e1;
      padding: 18px;
      border-radius: 8px;
      margin: 20px 0;
      border-left: 4px solid #ffa000;
    }

    .instructions h3 {
      margin-bottom: 10px;
      color: #e65100;
    }

    .day {
      margin-bottom: 35px;
      padding-bottom: 20px;
      border-bottom: 1px dashed #ccc;
    }

    .day h2 {
      font-size: 26px;
      color: #333;
      margin-bottom: 20px;
      padding-bottom: 8px;
      border-bottom: 2px solid #d32f2f;
    }

    .exercise {
      background: #fafafa;
      padding: 18px;
      margin-bottom: 16px;
      border-radius: 8px;
      border-left: 4px solid #8bc34a;
    }

    .exercise h3 {
      font-size: 20px;
      margin-bottom: 10px;
      color: #2e7d32;
    }

    .meta {
      font-size: 14px;
      color: #666;
      margin-bottom: 12px;
      font-weight: bold;
    }

    .exercise p {
      font-size: 15px;
      color: #444;
    }

    table {
      width: 100%;
      border-collapse: collapse;
      margin: 20px 0;
    }

    th, td {
      text-align: left;
      padding: 12px;
      border-bottom: 1px solid #eee;
    }

    th {
      background: #333;
      color: white;
      font-weight: bold;
    }

    tr:last-child td {
      border-bottom: none;
    }
 @media (max-width: 768px) {
      

      .header h1 {
        font-size: 26px;
      }

      .header p.subtitle {
        font-size: 16px;
      }

      .day h2 {
        font-size: 22px;
      }

      .exercise h3 {
        font-size: 18px;
      }

      .meta {
        font-size: 13px;
      }

      .exercise p {
        font-size: 14px;
      }

      th, td {
        padding: 8px;
        font-size: 13px;
      }
    }