body {
  margin: 0;
  background: #0d0d0d;
  font-family: 'Segoe UI', sans-serif;
  overflow: hidden;
}

/* Khung chính */
.center-box {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 560px;
  height: 280px;
  padding: 30px 50px;
  border-radius: 16px;
  overflow: hidden;
  z-index: 1;

  background: #1a1a1a; /* fallback khi chưa load gradient */
  box-shadow: 0 0 30px rgba(0, 255, 255, 0.1);
  backdrop-filter: blur(5px);
  transition: transform 0.3s ease;

  /* Thêm lớp phủ gradient xoay bên trong */
}
.center-box::before {
  content: '';
  position: absolute;
  inset: 0;
  background: conic-gradient(
    from 0deg,
    #1f1f1f,
    #3a3a3a,
    #1f1f1f
  );
  animation: spinGradient 8s linear infinite;
  z-index: 0;
  opacity: 0.4; /* Có thể tăng opacity để rõ hơn */
}

@keyframes spinGradient {
  from {
    transform: rotate(0deg);
  }
  to {
    transform: rotate(360deg);
  }
}

.center-box:hover {
  transform: translate(-50%, -50%) scale(1.05);
  
}
.site-title {
  position: absolute;
  top: 40px;
  left: 50%;
  transform: translateX(-50%);
  font-size: 36px;
  font-weight: bold;
  color: #00ffff;
  text-shadow: 0 0 10px #00ffff, 0 0 20px #00ffff;
  opacity: 0;
  animation: fadeInTitle 1.5s ease-out forwards;
}

@keyframes fadeInTitle {
  from {
    opacity: 0;
    transform: translateX(-50%) translateY(-10px);
  }
  to {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
  }
}

/* Particles */
.particles-container {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 2;
  pointer-events: none;
}

/* Nội dung */
.content {
  position: relative;
  z-index: 3;
  text-align: center;
}
.download-button {
  display: inline-block;
  padding: 15px 35px;
  font-size: 20px;
  font-weight: bold;
  color: white;
  background: transparent; /* nền trong suốt */
  border: 2px solid #00ffff; /* viền cyan */
  border-radius: 12px;
  box-shadow: none; /* bỏ shadow */
  text-shadow: 0 0 8px white;
  text-decoration: none;
  margin-top: 25px;
  transition: 0.3s;
}

.download-button i {
  margin-right: 10px;
}

.download-button:hover {
  transform: scale(1.05);
  box-shadow: 0 0 20px #00ffff; /* thêm glow khi hover */
  background: rgba(0, 255, 255, 0.1); /* hover có nền mờ nhẹ */
}

.glow-text-white {
  color: white;
  font-size: 34px;
  font-weight: bold;
  text-shadow: 0 0 12px white, 0 0 24px white;
  margin-bottom: 10px;
}
.glow-text-blue {
  color: #00bfff;
  font-size: 20px;
  font-weight: bold;
  text-shadow: 0 0 4px #00bfff;
  margin: 8px 0;
}
.glow-text-main {
  color: #ffffff;
  font-size: 40px;
  font-weight: bold;
  margin: 20px 0;
  text-shadow: 0 0 12px #00ffff, 0 0 28px #00ffff;
}

.links a {
  color: #00bfff;
  text-decoration: none;
  margin: 0 10px;
  font-size: 18px;
  font-weight: bold;
  text-shadow: 0 0 6px #00bfff;
  transition: 0.3s;
  cursor: pointer;
}
.links a:hover {
  color: #ffffff;
}
/* Nút settings */
.settings-icon {
  position: absolute;
  top: 10px;
  right: 10px;
  width: 28px;
  height: 28px;
  cursor: pointer;
  z-index: 4;
  transition: transform 0.2s ease;
}

.settings-icon:hover {
  transform: scale(1.2) rotate(30deg);
}

/* Hộp settings */
.settings-box {
  position: absolute;
  top: 50px;
  right: 50px;
  width: 300px;
  padding: 15px 20px;
  background: rgba(46, 43, 43, 0.8);
  border: 2px solid #00ffff;
  border-radius: 10px;
  box-shadow: 0 0 15px rgba(0, 255, 255, 0.5);
  color: #ffffff;
  z-index: 5;
  cursor: move;
  display: none;
  user-select: none;
}

/* Hiệu ứng text chạy ra từ từ  */
    .settings-box p {
      opacity: 0;
      transform: translateX(-30px);
      color: #ffffff;
      text-shadow: 0 0 8px rgba(0, 255, 255, 0.6);
      margin: 15px 0;
      font-size: 16px;
      font-weight: 500;
      padding: 8px 0;
      border-left: 3px solid transparent;
      padding-left: 10px;
      transition: all 0.3s ease;
    }
.settings-box p:hover {
      border-left-color: #00ffff;
      background: rgba(0, 255, 255, 0.1);
      transform: translateX(5px);
    }

    /* Animation cho từng dòng */
    .settings-box p:nth-child(2) { animation: slideInLeft 0.6s ease-out 0.1s forwards; }
    .settings-box p:nth-child(3) { animation: slideInLeft 0.6s ease-out 0.3s forwards; }
    .settings-box p:nth-child(4) { animation: slideInLeft 0.6s ease-out 0.5s forwards; }
    .settings-box p:nth-child(5) { animation: slideInLeft 0.6s ease-out 0.7s forwards; }
    .settings-box p:nth-child(6) { animation: slideInLeft 0.6s ease-out 0.9s forwards; }
    .settings-box p:nth-child(7) { animation: slideInLeft 0.6s ease-out 0.11s forwards; }


@keyframes slideInLeft {
      from {
        opacity: 0;
        transform: translateX(-30px);
      }
      to {
        opacity: 1;
        transform: translateX(0);
      }
    }

    /* Reset animation khi mở lại */
    .settings-box.reset-animation p {
      animation: none;
      opacity: 0;
      transform: translateX(-30px);
    }