/* CSS Reset & Base Styles */
:root {
    --sand-primary: #c2b280; /* Màu cát chính */
    --sand-dark: #8c7853;    /* Màu cát đậm */
    --text-dark: #3a3a3a;   /* Màu chữ chính */
    --text-light: #f5f5f5;
    --background-light: #fffaf0; /* Màu nền hơi ngà */
    --shadow: 0 10px 20px rgba(0,0,0,0.1);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Montserrat', sans-serif;
    line-height: 1.6;
    background-color: var(--background-light);
    color: var(--text-dark);
}

.container {
    max-width: 1200px;
    margin: auto;
    padding: 0 20px;
}

h1, h2, h3 {
    font-family: 'Playfair Display', serif;
    font-weight: 700;
}

h1 { font-size: 3.5rem; }
h2 { font-size: 2.5rem; color: var(--sand-dark); margin-bottom: 1rem; text-align: center; }
h3 { font-size: 1.5rem; color: var(--sand-primary); }

section {
    padding: 80px 0;
}

/* Animation on Scroll */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* --- Components --- */
.btn {
    display: inline-block;
    padding: 12px 30px;
    background-color: var(--sand-primary);
    color: white;
    text-decoration: none;
    border-radius: 50px;
    font-weight: bold;
    transition: background-color 0.3s, transform 0.3s;
    box-shadow: 0 4px 10px rgba(0,0,0,0.15);
}

.btn:hover {
    background-color: var(--sand-dark);
    transform: translateY(-3px);
}

/* --- Header & Hero Section --- */
#hero {
    /* === UPDATED CODE START === */
    background: linear-gradient(rgba(0, 0, 0, 0.5), rgba(0, 0, 0, 0.5)), url('https://tranhcatdong.com/uploads/news/2025_10/hoa-si-nguyen-the-nhan.jpg') no-repeat center center/cover;
    /* === UPDATED CODE END === */
    height: 100vh;
    color: white;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    position: relative;
}
#hero::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 100px;
    background: linear-gradient(to top, var(--background-light), transparent);
}

#hero h1 {
    margin-bottom: 20px;
    text-shadow: 2px 2px 8px rgba(0,0,0,0.7);
}

#hero p {
    font-size: 1.2rem;
    max-width: 600px;
    margin-bottom: 30px;
    text-shadow: 1px 1px 4px rgba(0,0,0,0.7);
}

/* --- Introduction Section --- */
#intro .container {
    display: flex;
    align-items: center;
    gap: 50px;
}
#intro .intro-text { flex: 1; }
#intro .intro-image { flex: 1; text-align: center; }
#intro .intro-image img {
    width: 350px;
    height: 350px;
    object-fit: cover;
    border-radius: 50%;
    border: 8px solid var(--sand-primary);
    box-shadow: var(--shadow);
}

/* --- Services Section --- */
#services {
    background-color: #fff;
}
.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-top: 40px;
}
.service-card {
    background: var(--background-light);
    padding: 30px;
    text-align: center;
    border-radius: 10px;
    box-shadow: var(--shadow);
    transition: transform 0.3s, box-shadow 0.3s;
}
.service-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0,0,0,0.15);
}
.service-card .icon {
    font-size: 3rem;
    color: var(--sand-primary);
    margin-bottom: 15px;
}

/* --- Portfolio Section --- */
.portfolio-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 20px;
    margin-top: 40px;
}
.portfolio-item {
    position: relative;
    overflow: hidden;
    border-radius: 10px;
    box-shadow: var(--shadow);
}
.portfolio-item img {
    width: 100%;
    display: block;
    transition: transform 0.4s;
}
.portfolio-item:hover img {
    transform: scale(1.1);
}
.portfolio-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.7);
    color: white;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    opacity: 0;
    transition: opacity 0.4s;
    text-align: center;
    padding: 20px;
}
.portfolio-item:hover .portfolio-overlay {
    opacity: 1;
}
.video-wrapper {
    position: relative;
    padding-bottom: 56.25%; /* 16:9 Aspect Ratio */
    height: 0;
    overflow: hidden;
    border-radius: 10px;
    box-shadow: var(--shadow);
    margin-top: 40px;
}
.video-wrapper iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}


/* --- CTA Section --- */
#cta {
    background: var(--sand-dark);
    color: var(--text-light);
    text-align: center;
}
#cta h2 { color: white; }
#cta p {
    max-width: 700px;
    margin: 0 auto 30px;
}

/* --- Footer --- */
footer {
    background: var(--text-dark);
    color: var(--text-light);
    text-align: center;
    padding: 40px 0;
}
.social-links a {
    color: white;
    margin: 0 15px;
    font-size: 1.5rem;
    transition: color 0.3s;
}
.social-links a:hover {
    color: var(--sand-primary);
}
footer p {
    margin-top: 20px;
}

/* --- Zalo Float Button --- */
.zalo-float {
    position: fixed;
    bottom: 25px;
    right: 25px;
    z-index: 1000;
}
.zalo-float img {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    box-shadow: 0 4px 10px rgba(0,0,0,0.3);
    transition: transform 0.3s;
}
.zalo-float:hover img {
    transform: scale(1.1);
}

/* Responsive Design */
@media (max-width: 768px) {
    h1 { font-size: 2.5rem; }
    h2 { font-size: 2rem; }
    section { padding: 60px 0; }
    #intro .container { flex-direction: column; }
    #intro .intro-image img { width: 250px; height: 250px; }
}