/* BANNER */
/* CARD DESKTOP */
.desktop-course-card {
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.15);
    background-color: white;
    margin-top: -160px;
    position: sticky;
    top: 20px;
    z-index: 10;
}

.desktop-course-card img {
    width: 100%;
    height: 220px;
    object-fit: cover;
}

/* FIXED BOTTOM BAR (MOBILE) */
.mobile-fixed-bar {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: white;
    box-shadow: 0 -5px 20px rgba(0, 0, 0, 0.1);
    padding: 12px 20px;
    display: none;
    align-items: center;
    justify-content: space-between;
    z-index: 1000;
}

.mobile-fixed-bar .price {
    font-size: 1.4rem;
    font-weight: 800;
    color: #d63031;
    margin: 0;
}

.btn-buy-mobile {
    background-color: #ffc107 !important;
    border: none;
    font-weight: bold;
    padding: 10px 25px;
    border-radius: 5px;
}

/* RESPONSIVE LOGIC */
@media (max-width: 991.98px) {
    .desktop-course-card {
        display: none !important;
    }

    .mobile-fixed-bar {
        display: flex;
    }

    body {
        padding-bottom: 80px;
    }

    .header-section {
        padding: 40px 0;
    }

    .mobile-thumb-container {
        display: block !important;
    }
}

.mobile-thumb-container {
    display: none;
    margin-bottom: 25px;
    background: white;
}

.mobile-thumb-container img {
    width: 100%;
}

/* NỘI DUNG VÀ NÚT XEM THÊM */
.info-content {
    position: relative;
    max-height: 250px;
    overflow: hidden;
    transition: max-height 0.3s ease;
}

.info-content.expanded {
    max-height: none;
}

.read-more-overlay {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 80px;
    background: linear-gradient(transparent, white);
    display: flex;
    align-items: flex-end;
    justify-content: flex-start;
}

.info-content.expanded .read-more-overlay {
    display: none;
}

.btn-toggle-content {
    background: none;
    border: none;
    color: #ffc107;
    font-weight: bold;
    padding: 0;
    cursor: pointer;
    font-size: 0.9rem;
}

/* TABS */
.nav-tabs .nav-link {
    color: #666;
    font-weight: 600;
    border: none;
    padding: 15px 15px;
    font-size: 0.9rem;
}

.nav-tabs .nav-link.active {
    color: #ffc107;
    border-bottom: 3px solid #ffc107;
    background: none;
}

.curriculum-title {
    font-size: 1.5rem;
    font-weight: bold;
    margin: 30px 0 15px;
}

.accordion-button {
    background-color: #fef5d9 !important;
    font-weight: 600;
}

.curriculum-title {
    font-size: 1.6rem;
    font-weight: bold;
    margin: 30px 0 20px 0;
    color: #222;
}

.accordion-item {
    border: none;
    margin-bottom: 10px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.05);
}

.accordion-button {
    background-color: #fef5d9 !important;
    color: #333 !important;
    font-weight: 600;
    border-radius: 8px !important;
}

.accordion-button:not(.collapsed) {
    box-shadow: none;
}

.lesson-item {
    padding: 12px 20px;
    border-bottom: 1px solid #f8f9fa;
    display: flex;
    align-items: center;
    transition: background 0.2s;
}

.lesson-item:hover {
    background-color: #fffdf5;
}

.lesson-item i {
    font-size: 10px;
    color: #ffc107;
    margin-right: 15px;
}

.contact-section {
    font-family: Arial, sans-serif;
    padding: 20px;
    background-color: #f9f9f9;
    border-radius: 8px;
    max-width: 100%;
    border-left: 5px solid #ff4d4d; /* Màu nhấn */
    margin: 10px 0;
}
.contact-title {
    margin-top: 0;
    color: #333;
}
.contact-item {
    margin-bottom: 10px;
    line-height: 1.6;
    display: flex;
    align-items: center;
}
.icon {
    margin-right: 10px;
    font-size: 1.2em;
}
.contact-link {
    color: #ff4d4d;
    text-decoration: none;
    font-weight: bold;
}
.contact-link:hover {
    text-decoration: underline;
}