header {
        display: flex;
        justify-content: space-between;
        align-items: center;
        padding: 20px 50px;
        border-bottom: 1px solid #eee;
        background: #fff;
      }
      .logo {
        display: flex;
        align-items: center;
        gap: 10px;
      }
      .logo-box {
        width: 12px;
        height: 12px;
        background: blue;
        display: inline-block;
      }
      .name {
        font-weight: 800;
        font-size: 20px;
      }
      .title {
        font-weight: 400;
        font-size: 16px;
        color: #333;
      }

      /* NAVIGATION */
      nav a {
        margin-left: 25px;
        text-decoration: none;
        font-size: 15px;
        color: #000; /* chữ đen */
        transition: color 0.3s;
      }
      nav a:hover {
        color: blue;
      }
      nav a.active {
        color: blue; /* trang hiện tại thì xanh */
      }

      /* ====== CONTACT ====== */
      .contact-section {
        padding: 50px;
        text-align: center;
      }

      .form-container {
        max-width: 500px;
        margin: auto;
        background: #fafafa;
        padding: 30px;
        border-radius: 8px;
        box-shadow: 0 3px 10px rgba(0, 0, 0, 0.1);
      }

      .contact-form {
        display: flex;
        flex-direction: column;
        gap: 15px;
      }

      .contact-form input,
      .contact-form textarea {
        padding: 12px;
        border: 1px solid #ccc;
        border-radius: 5px;
        font-size: 16px;
      }

      .contact-form button {
        padding: 12px;
        background: blue;
        color: white;
        border: none;
        border-radius: 5px;
        font-weight: bold;
        cursor: pointer;
        transition: 0.3s;
      }
      .contact-form button:hover {
        background: #0044cc;
      }

      /* ====== FOOTER ====== */
      footer {
        background: #fff;
        padding: 30px 50px;
        font-size: 14px;
        border-top: 1px solid #eee;
        text-align: center;
      }

      .footer-info {
        display: flex;
        justify-content: center;
        text-align: center;
        gap: 60px;
        margin-top: 20px;
        flex-wrap: wrap;
      }

      .socials a {
        margin: 0 5px;
      }

      .copyright {
        margin-top: 30px;
        font-size: 14px;
        color: #555;
      }