* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    background-color: #000;
    color: #fff;
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    line-height: 1.6;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 40px 20px;
}

/* Navbar */
.nav-links {
    background: rgba(255, 255, 255, 0.05);
    padding: 4px;
    border-radius: 8px;
}

.nav-links a {
    color: var(--text-sub);
    text-decoration: none;
    padding: 6px 16px;
    font-size: 14px;
    transition: 0.2s;
}

.nav-links a.active {
    background: #222;
    color: #fff;
    border-radius: 6px;
}

.logo img {
    border-radius: 50%;
    background: #fff;
}

.nav-links {
    display: flex;
    list-style: none;
    align-items: center;
    gap: 25px;
}

.nav-links a {
    color: #a1a1aa;
    text-decoration: none;
    transition: 0.3s;
}

.nav-links a:hover {
    color: #fff;
}

.contact-btn {
    background: #18181b;
    padding: 8px 16px;
    border-radius: 8px;
    border: 1px solid #27272a;
    color: #fff !important;
}

/* Typography */
h1 { font-size: 2.5rem; margin-bottom: 5px; }
h2 { font-size: 1.5rem; margin-top: 40px; margin-bottom: 10px; }
.subtitle { color: #a1a1aa; font-size: 1.2rem; }
.description { color: #71717a; margin: 20px 0; }

/* Grid Systems */
.social-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 15px;
}

.booking-grid, .cert-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

/* Cards chung cho Social, Booking và Cert */
.social-card, .booking-card, .cert-card {
    background: #09090b;
    border: 1px solid #18181b;
    border-radius: 12px;
    padding: 20px;
    transition: 0.3s;
}

.social-card {
    display: flex;
    align-items: center;
    gap: 15px;
    cursor: pointer;
}

.social-card:hover, .booking-card:hover, .cert-card:hover {
    background: #18181b;
    border-color: #27272a;
}

/* --- PHẦN CHỈNH SỬA CHO CERTIFICATE NHỎ LẠI --- */
.cert-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    cursor: pointer;
}

.cert-thumb {
    width: 100%;       /* Chiều rộng bằng ô chứa */
    height: 150px;     /* Chiều cao cố định để nhỏ gọn */
    object-fit: cover; /* Cắt ảnh vừa khung không bị móp */
    border-radius: 8px;
    margin-bottom: 12px;
    border: 1px solid #18181b;
}

.cert-info {
    text-align: center;
}

.cert-info h3 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 4px;
}

.cert-info p {
    color: #71717a;
    font-size: 0.8rem;
}
/* ---------------------------------------------- */

.card-title { font-weight: 600; }
.card-detail { color: #71717a; font-size: 0.9rem; }

/* Booking Card Specifics */
.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 10px;
}

.badge {
    background: #18181b;
    color: #71717a;
    padding: 4px 8px;
    border-radius: 4px;
    font-size: 0.75rem;
}

.booking-card p {
    color: #71717a;
    margin-bottom: 25px;
}

/* Modal & Lightbox */
.modal {
    display: none;
    position: fixed;
    z-index: 9999;
    inset: 0;
    align-items: center;
    justify-content: center;
}

.modal-overlay {
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.85);
    backdrop-filter: blur(10px);
}

.modal-content {
    position: relative;
    z-index: 10001;
    max-width: 90%;
    max-height: 80vh;
    border-radius: 12px;
    transform: scale(0.9);
    transition: 0.3s;
}

.modal.active .modal-content { transform: scale(1); }

.nav-btn {
    position: absolute;
    z-index: 10002;
    top: 50%;
    transform: translateY(-50%);
    background: none;
    border: none;
    color: white;
    font-size: 2rem;
    cursor: pointer;
    padding: 20px;
}

.prev { left: 10px; }
.next { right: 10px; }

.close-btn {
    position: absolute;
    top: 20px;
    right: 30px;
    z-index: 10003;
    color: white;
    font-size: 3rem;
    cursor: pointer;
}

/* Responsive */
@media (max-width: 768px) {
    .social-grid, .booking-grid, .cert-grid {
        grid-template-columns: 1fr;
    }
}

/* ===== NAVBAR CENTER FIX ===== */
.navbar {
    position: relative;
    display: flex;
    justify-content: center; /* menu ra giữa */
    align-items: center;
    padding: 20px 0;
}

.navbar .logo {
    position: absolute;
    left: 32px; /* logo nằm trái */
}
/* ============================ */