.hero {
      background: linear-gradient(rgba(0,0,0,0.5), rgba(0,0,0,0.5)), 
      url("./bg/bg_web.jpg") center/cover no-repeat;
      color: white;
      background-size: cover; /* giúp responsive */
      height: 90vh; /* full màn hình */

      display: flex;
      justify-content: center;
      align-items: center;
      text-align: center;
      position: relative;
      overflow: hidden; /* đảm bảo overlay không tràn ra ngoài */
      padding: 2rem;
    }
/* Overlay mờ cho chữ nổi bật hơn */
.hero::before {
   content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.4); /* màu overlay */
    z-index: 0; /* luôn nằm dưới */
}

.hero .container {
  position: relative; /* để chữ nằm trên overlay */
  z-index: 1;
}
@media (max-width: 768px) {
  .hero {
    background: url("./bg/bg_web.jpg") no-repeat center center;
    background-size: cover;
    height: 70vh; /* bớt cao trên mobile */
  }
}
.btn-muahang {
      background: #e63946;
      color: #fff;
    }
.btn-hocthu {
    background: #ffb703;
    color: #000;
    font-weight: 600;
}
#ageNote {
  border-radius: 12px;
  font-size: 0.95rem;
  line-height: 1.4;
}
.cta-section {
    background: #f8f9fa;
    padding: 50px 20px;
    text-align: center;
}
.hero h1 { font-size: 3rem; font-weight: bold; }
.feature-icon { font-size: 2rem; color: #0d6efd; }
.header { background: #0068ff;  }
footer { background: #f8f9fa; padding: 20px 0; text-align: center; margin-top: 40px; }
#hotline-btn {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background: #0068ff;
    border-radius: 50%;
    width: 60px;
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 10px rgba(0,0,0,0.3);
    z-index: 9999;
    transition: transform 0.2s;
}
#hotline-btn:hover {
    transform: scale(1.1);
}
#hotline-btn img {
    width: 35px;
    height: 35px;
}
.buy-btn {
    padding: 10px 20px;
    background: #28a745;
    color: white;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}
.buy-btn:disabled {
    background: #aaa;
    cursor: not-allowed;
}

/* Spinner tròn xoay */
.spinner {
    border: 3px solid #f3f3f3;
    border-top: 3px solid white;
    border-radius: 50%;
    width: 16px;
    height: 16px;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}
.course-card {
    background: #fff;
    padding: 20px;
    border-radius: 12px;
    transition: all 0.3s ease;
    height: 100%;
}
.course-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.15);
}
.course-title {
    color: #d32f2f;
    font-weight: 600;
    margin-top: 15px;
    margin-bottom: 10px;
}
.course-img {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    object-fit: cover;
    margin-bottom: 10px;
    box-shadow: 0 4px 10px rgba(0,0,0,.1);
}
.btn-custom {
    background-color: #1e88e5;
    border: none;
    font-weight: 600;
    padding: 12px 24px;
    border-radius: 8px;
}
.btn-custom:hover {
    background-color: #1565c0;
}
.section-title {
  text-align: center;
  border-bottom: 1px solid #ccc;
  line-height: 0.1em;
  margin: 30px 0 40px;
}

.section-title span {
  background: #fff; /* màu nền trùng với nền website */
  font-size: 32px; /* mặc định desktop */
  color: #004a99; /* xanh đậm nhấn mạnh */
  font-weight: 700;
  padding: 0 15px;
  font-weight: bold;
  
}

@media (max-width: 991px) {
  .section-title span {
    font-size: 26px;
  }
}

@media (max-width: 767px) {
  .section-title span {
    font-size: 22px;
  }
}


.card-title {
  color: #007bff;   /* xanh dương đậm */
  font-weight: 600;
  font-size: 18px;
  margin-bottom: 8px;
}
.product-price {
  font-size: 16px;
  font-weight: bold;
}

.product-price .old-price {
  color: #ff80aa;         /* hồng nhạt */
  text-decoration: line-through;
  margin-right: 8px;
  font-weight: normal;
}

.product-price .new-price {
  color: #e60073;         /* hồng đậm nổi bật */
}
.footer {
  background-color: #004a99; /* xanh đậm */
  text-align: left;
}

.footer p, 
.footer a {
  color: #fff;
  font-size: 15px;
}

.footer a.footer-link {
  text-decoration: none;
  color: #fff;
}

.footer a.footer-link:hover {
  text-decoration: underline;
  color: #ffd700; /* vàng nhấn khi hover */
}

.social-icons a {
  display: inline-block;
  width: 38px;
  height: 38px;
  line-height: 38px;
  border-radius: 50%;
  background: #fff;
  color: #004a99;
  text-align: center;
  margin-right: 8px;
  font-size: 18px;
  transition: 0.3s;
}

.social-icons a:hover {
  background: #ffd700;
  color: #004a99;
}
 
 
.hotline  {
  
  text-decoration: none;
  font-weight: bold;
}
.hotline .text a {
  
  text-decoration: none;
  font-weight: bold;
}

.hotline .text a:hover {
  color: #ff6600; /* hover đổi sang cam */
}
.video-wrapper {
  max-width: 800px;   /* Chiều rộng tối đa */
  margin: 0 auto;     /* Căn giữa */
  position: relative;
}
.video-thumbnail {
  position: relative;
  cursor: pointer;
  padding-bottom: 56.25%; /* Tỷ lệ 16:9 */
  height: 0;
  overflow: hidden;
  border-radius: 16px;
  box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}
.video-thumbnail img {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: 16px;
}
.play-button {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-size: 48px;
  background: rgba(0,0,0,0.5);
  color: white;
  padding: 20px 30px;
  border-radius: 50%;
  transition: 0.3s;
}
.play-button:hover {
  background: rgba(0,0,0,0.8);
}
.video-thumbnail iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border-radius: 16px;
}