body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    overflow: hidden;
    background-color: #000;
  }
  .container {
    position: relative;
    text-align: center;
    z-index: 1;
    color: #fff;
  }
  h1 {
    font-size: 36px;
    margin-bottom: 20px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.5);
  }
  h2 {
    font-size: 16px;
    margin-bottom: 20px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.5);
  }
  #countdown {
    font-size: 40px;
    font-weight: bold;
    color: #ffcc00;
    margin-bottom: 40px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.5);
  }
  #logo {
    width: 200px;
    height: auto;
    border-radius: 50%;
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.1);
  }
  video {
    position:absolute;
    top: 50%;
    left: 50%;
    min-width: 100%;
    min-height: 100%;
    width: auto;
    height: auto;
    transform: translate(-50%, -50%);
    z-index: -1;
    opacity: 0.8;
  }

  .footer-buttons {
    color: #fff;
    padding: 20px;
    text-align: center;
  }
  .footer-buttons button {
    background-color: #d93838;
    color: #fff;
    border: none;
    padding: 10px 20px;
    margin: 0 10px;
    cursor: pointer;
    transition: background-color 0.3s;
  }
  .footer-buttons button:hover {
    background-color: #c72e2e;
  }
  .text1 {
    font-size: 25px;
    margin-bottom: 20px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.5);
  }
  .button {
    background-image: linear-gradient(to bottom, #ff4d4d, #ffa64d);
    border: 2px solid #e69900;
    transition: background-image 0.3s ease, border-color 0.3s ease;
  }
  .button {
    font-size: 1em;
    padding: 10px;
    color: #fff;
    border: 2px solid yellow;
    border-radius: 20px/50px;
    text-decoration: none;
    cursor: pointer;
    transition: all 0.3s ease-out;
  }
  .button:hover {
    background: #FFCC00;
  }
  .overlay {
    position: fixed;
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
    transition: opacity 500ms;
    visibility: hidden;
    opacity: 0;
  }
  .overlay:target {
    visibility: visible;
    opacity: 1;
  }

  @media screen and (max-width: 700px) {
    .box {
      width: 70%;
    }
    .popup {
      width: 70%;
    }
  }

  header {
    position: fixed; 
    top: 0; 
    left: 0;
    width: 100%;
    background-color: red;
    color: #fff;
    padding: 10px 0;
  }

  .running-text-container {
    overflow: hidden;
  }

  .running-text {
    display: inline-block;
    margin: 0;
    animation: running-text 30s linear infinite;
  }

  .donate-btn {
            display: inline-block;
            padding: 12px 30px;
            font-size: 18px;
            font-weight: bold;
            text-align: center;
            text-decoration: none;
            color: #fff;
            background-color: #0096a1;
            border-radius: 8px;
            transition: background-color 0.3s, transform 0.2s;
        }

        /* Hiệu ứng khi di chuột vào */
        .donate-btn:hover {
            background-color: #007f88;
            transform: scale(1.05);
        }

        /* Hiệu ứng khi nhấn nút */
        .donate-btn:active {
            transform: scale(1.02);
        }

  @keyframes running-text {
    0% {
      transform: translateX(100%);
    }
    100% {
      transform: translateX(-100%);
    }
  }