/* BẢNG MÀU SIGNATURE */
:root {
    --bg-dark: #151515;
    --silver-white: #FFFFFF;
    --grad-bronze: linear-gradient(135deg, #6B4E2E 0%, #B08D57 50%, #F2E1B8 100%);
    --grad-gold: linear-gradient(135deg, #A67C40 0%, #F4D068 100%);
}

/* RESET & CƠ BẢN */
* { margin: 0; padding: 0; box-sizing: border-box; }
body {
    background-color: var(--bg-dark);
    color: var(--silver-white);
    font-family: 'Montserrat', sans-serif;
    line-height: 1.8;
    overflow-x: hidden;
}

h1, h2, h3, .brand { font-family: 'Playfair Display', serif; }

	/* =========================================
   TÙY CHỈNH THANH CUỘN (CUSTOM SCROLLBAR)
   ========================================= */

/* Dành cho Firefox */
html {
    scrollbar-width: thin;
    scrollbar-color: #A67C40 var(--bg-dark); /* Màu thanh cuộn và màu nền */
}

/* Dành cho Chrome, Edge, Safari */
::-webkit-scrollbar {
    width: 10px; /* Độ rộng của thanh cuộn dọc */
    height: 10px; /* Độ cao của thanh cuộn ngang (nếu có) */
}

/* Phần rãnh trượt (Track) */
::-webkit-scrollbar-track {
    background: var(--bg-dark);
    border-left: 1px solid rgba(176, 141, 87, 0.15); /* Đường viền nhẹ tạo độ sâu */
}

/* Phần thanh nắm (Thumb) */
::-webkit-scrollbar-thumb {
    /* Sử dụng dải màu gradient dọc theo tông vàng đồng của web */
    background: linear-gradient(180deg, #A67C40 0%, #F4D068 100%);
    border-radius: 6px; /* Bo góc cho thanh cuộn */
    border: 2px solid var(--bg-dark); /* Tạo khoảng cách giả giữa thumb và track */
}

/* Hiệu ứng khi di chuột lên thanh nắm */
::-webkit-scrollbar-thumb:hover {
    background: linear-gradient(180deg, #6B4E2E 0%, #B08D57 50%, #F2E1B8 100%);
}

/* GRADIENT TEXT CLASSES */
.text-bronze {
    background: var(--grad-bronze);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}
.text-gold {
    background: var(--grad-gold);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* BACKGROUND RỒNG CỐ ĐỊNH KHI CUỘN */
.dragon-bg-fixed {
    position: fixed;
    top: 100px;
    left: 0;
    width: 100vw;
    height: calc(100vh - 100px);
    z-index: -2;
    display: flex;
    justify-content: center;
    align-items: center;
    pointer-events: none;
}
.dragon-bg-fixed img {
    width: 80%;
    max-width: 850px;
    opacity: 0.2;
    object-fit: contain;
}

/* LỚP SƯƠNG MỜ BAO PHỦ NỀN CỐ ĐỊNH */
.overlay-fixed {
    position: fixed;
    top: 0; left: 0; width: 100vw; height: 100vh;
    background: radial-gradient(circle, rgba(21,21,21,0.1) 20%, rgba(21,21,21,1) 85%);
    z-index: -1;
    pointer-events: none;
}

/* HEADER */
header {
    padding: 20px 50px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid rgba(176, 141, 87, 0.15);
    position: fixed;
    width: 100%;
    top: 0;
    background: rgba(21, 21, 21, 0.9);
    backdrop-filter: blur(12px);
    z-index: 1000;
    height: 80px;
}
.logo { font-size: 22px; font-weight: 700; letter-spacing: 2px; text-transform: uppercase; z-index: 1001;}

/* Nút menu mobile */
.mobile-menu-btn {
    display: none;
    font-size: 28px;
    color: var(--silver-white);
    cursor: pointer;
    z-index: 1001;
    user-select: none;
}

nav ul { list-style: none; display: flex; gap: 40px; margin: 0; padding: 0; }

nav a {
    background: var(--grad-gold);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-decoration: none;
    font-size: 13px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 2px;
    transition: 0.3s ease;
}
nav a:hover {
    background: var(--grad-bronze);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* HERO SECTION */
.hero {
    height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    position: relative;
    padding: 0 20px;
    z-index: 1;
}
.hero-content { max-width: 800px; }
.hero h1 {
    font-size: 4.5rem;
    margin-bottom: 25px;
    letter-spacing: 4px;
    text-shadow: 0 5px 15px rgba(0,0,0,0.8);
}
.hero p {
    font-size: 1.1rem;
    color: #ccc;
    margin-bottom: 40px;
    letter-spacing: 1px;
    font-weight: 300;
}
.btn-primary {
    background: var(--grad-gold);
    color: var(--bg-dark);
    padding: 16px 45px;
    text-decoration: none;
    font-weight: 600;
    border-radius: 3px;
    font-size: 0.95rem;
    letter-spacing: 2px;
    transition: all 0.3s ease;
    text-transform: uppercase;
    display: inline-block;
}
.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(244, 208, 104, 0.25);
    background: var(--silver-white);
}

/* CÁC SECTION NỘI DUNG */
.section {
    padding: 120px 10%;
    position: relative;
    z-index: 2;
}
.section:nth-child(even) {
    background-color: transparent; 
    /*border-top: 1px solid rgba(176, 141, 87, 0.1);
    border-bottom: 1px solid rgba(176, 141, 87, 0.1);*/
    backdrop-filter: none; 
}

.content-block {
    max-width: 900px;
    margin: 0 auto;
    text-align: center;
}

.section-title { font-size: 2.8rem; margin-bottom: 20px; letter-spacing: 2px; }
.section-subtitle { font-size: 1rem; color: #888; text-transform: uppercase; letter-spacing: 4px; margin-bottom: 30px; }
.section-divider { width: 80px; height: 2px; background: var(--grad-bronze); margin: 0 auto 50px; }

.content-text {
    font-size: 1.15rem;
    color: #d1d1d1;
    text-align: justify;
    text-align-last: center;
    margin-bottom: 30px;
    line-height: 2;
}

/* KHỐI NỘI DUNG CỐT CÁCH */
.pillar-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
    margin-top: 70px;
    text-align: left;
}
.pillar-box {
    padding: 40px 30px;
    background: transparent; 
    /*border-top: 3px solid rgba(107, 78, 46, 0.5);*/ 
    transition: 0.4s ease;
    position: relative;
}
.pillar-box:hover {
    background: rgba(176, 141, 87, 0.05); 
    border-top-color: #F4D068;
    transform: translateY(-5px);
}
.pillar-box h3 {
    font-size: 1.6rem;
    margin-bottom: 20px;
    padding-bottom: 15px;
    border-bottom: 1px solid rgba(255,255,255,0.05);
}
.pillar-box p { color: #aaa; font-size: 0.95rem; text-align: justify; line-height: 1.8; }

/* KHỐI GIA PHẢ TRỌNG TÂM */
.genealogy-focus {
    margin-top: 80px;
    padding: 60px;
    background: linear-gradient(to right, rgba(21,21,21,0.8), rgba(107, 78, 46, 0.1), rgba(21,21,21,0.8)); 
    border: 1px solid rgba(176, 141, 87, 0.2);
    border-radius: 4px;
}
.genealogy-focus blockquote {
    font-family: 'Playfair Display', serif;
    font-size: 1.6rem;
    color: #F2E1B8;
    font-style: italic;
    line-height: 1.6;
    margin-bottom: 30px;
}

/* FOOTER */
footer {
    text-align: center;
    padding: 60px 20px;
    background: #090909;
    position: relative;
    z-index: 2;
    border-top: 1px solid rgba(176, 141, 87, 0.3);
}
footer h2 { font-size: 1.5rem; letter-spacing: 3px; margin-bottom: 15px; }
footer p { font-size: 0.9rem; color: #666; }

/* =========================================
   RESPONSIVE MOBILE STYLES (Cập nhật mới)
   ========================================= */
@media (max-width: 768px) {
    /* Header & Nav Menu */
    header { padding: 15px 20px; height: 70px; }
    .logo { font-size: 18px; }
    .mobile-menu-btn { display: block; } /* Hiện nút menu */
    nav {
        position: absolute;
        top: 70px;
        left: 0;
        width: 100%;
        background: rgba(21, 21, 21, 0.98);
        display: none; /* Ẩn menu mặc định */
        flex-direction: column;
        text-align: center;
        padding: 20px 0;
        border-bottom: 1px solid rgba(176, 141, 87, 0.2);
        box-shadow: 0 10px 30px rgba(0,0,0,0.5);
    }
    nav.active { display: flex; } /* Hiện menu khi bấm */
    nav ul { flex-direction: column; gap: 20px; }
    nav a { font-size: 15px; }

    /* Rồng Mobile - Hiển thị toàn vẹn */
    .dragon-bg-fixed { top: 70px; height: calc(100vh - 70px); }
    .dragon-bg-fixed img { 
        width: 95vw; /* Giới hạn chiều rộng */
        max-height: 60vh; /* Giới hạn chiều cao để không bị tràn */
        opacity: 0.15;
    } 

    /* Typography & Padding rút gọn */
    .hero { padding-top: 70px; }
    .hero h1 { font-size: 2.5rem; letter-spacing: 2px; }
    .hero p { font-size: 1rem; padding: 0 10px; }
    .section { padding: 80px 5%; }
    .section-title { font-size: 2.2rem; margin-bottom: 15px; }
    .content-text { text-align-last: left; font-size: 1.05rem; }
    
    /* Lưới nội dung */
    .pillar-grid { grid-template-columns: 1fr; gap: 30px; margin-top: 40px; }
    .pillar-box { padding: 25px 20px; }
    
    /* Khối gia phả */
    .genealogy-focus { padding: 40px 20px; margin-top: 50px; }
    .genealogy-focus blockquote { font-size: 1.2rem; }
    
    footer { padding: 40px 20px; }
}