@charset "utf-8";
/* CSS Document */
  * { box-sizing: border-box; margin: 0; padding: 0; }

    body {
      font-family: Arial, Helvetica, sans-serif;
      background-color: #f4f4f4;
      color: #333;
      line-height: 1.6;
      padding-bottom: 3rem;
    }

    .header {
      background-color: #2c3e50;
      padding: 20px;
      text-align: center;
    }

    .header img {
      max-width: 100%;
      height: auto;
      max-height: 80px;
    }

    .nav {
      background-color: #34495e;
      padding: 10px 0;
      text-align: center;
    }

    .nav a {
      color: #fff;
      text-decoration: none;
      padding: 10px 20px;
      margin: 0 10px;
      font-weight: 700;
      transition: background-color 0.3s;
    }

    .nav a:hover {
      background-color: #2c3e50;
      border-radius: 5px;
    }

    .container-wrapper {
      max-width: 1240px;
      margin: 20px auto;
      padding: 0 20px;
    }

    .section {
      background: #ffffff;
      border-radius: 10px;
      padding: 1.5rem;
      box-shadow: 0 4px 8px rgba(0,0,0,0.1);
      margin-bottom: 1.5rem;
    }

    .section-header {
      font-size: 1.3rem;
      font-weight: bold;
      margin-bottom: 1rem;
      border-bottom: 2px solid #ecf0f1;
      padding-bottom: 0.5rem;
      color: #2c3e50;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }

    .section-header::after {
      content: '▼';
      font-size: 0.9rem;
      transition: transform 0.3s ease;
    }

    .section-header.collapsed::after {
      transform: rotate(-180deg);
    }

    .section-content {
      display: none;
      transition: max-height 0.3s ease, opacity 0.3s ease;
    }

    .section-content:not(.collapsed) {
      display: block;
    }

    .link-item {
      background: #ecf0f1;
      border-radius: 8px;
      padding: 1rem;
      margin-bottom: 1rem;
      transition: background 0.3s ease;
    }

    .link-item:hover {
      background: #dfe6e9;
    }

    .description {
      font-size: 0.9rem;
      color: #34495e;
      margin-top: 0.5rem;
    }

    ul {
      margin-top: 0.5rem;
      padding-left: 1.25rem;
    }

    .video-container {
      position: relative;
      padding-bottom: 56.25%;
      height: 0;
      overflow: hidden;
      background: #ecf0f1;
      border-radius: 8px;
      margin-bottom: 1rem;
    }

    .video-container iframe {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      border: none;
    }

    .bottom-links {
      background-color: #ecf0f1;
      text-align: center;
      padding: 15px 0;
      font-size: 0.95rem;
      border-top: 1px solid #ccc;
      border-bottom: 1px solid #ccc;
    }

    .bottom-links a {
      margin: 0 15px;
      color: #2c3e50;
      text-decoration: none;
      font-weight: 500;
    }

    .bottom-links a:hover {
      text-decoration: underline;
    }

    .footer {
      background-color: #2c3e50;
      color: #fff;
      text-align: center;
      padding: 20px;
    }