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

/* body */
body {
    font-family: 'Segoe UI', Tahoma, sans-serif;
    background-color: #f4f4f9;
    color: #333;
    line-height: 1.6;
}

/* Header */

header {
    background: linear-gradient(rgba(0, 0, 0, 0.6), rgba(0, 0, 0, 0.6)), url('img/hoian.jpg') center/cover no-repeat;
    color: white;
    height: 75vh;
    display: flex;
    justify-content: center;
    align-items: center;
    text-align: center;
    flex-direction: column;
    padding: 0 20px;
    box-shadow: inset 0 0 15px rgba(0, 0, 0, 0.7); 
}

header h1 {
    font-family: "Anton", sans-serif;
    font-size: 6.5rem; 
    text-shadow: 4px 4px 15px rgba(0, 0, 0, 0.8); 
    letter-spacing: 3.5px; 
    margin-bottom: 5px;
}

header p {
    font-family: 'Anton', sans-serif; 
    font-size: 2rem; 
    margin-top: 5px;
    color: #d1f4f6; 
    letter-spacing: 2px;
}

/* Thanh điều hướng */

nav {
    position: sticky; 
    top: 0;
    background: linear-gradient(135deg, #13b3be, #0f7c80);
    padding: 12px 40px;
    text-align: center;
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    z-index: 1000; 
}

nav a {
    color: white;
    margin: 0 20px;
    font-size: 1.3rem;
    padding: 10px 20px;
    border-radius: 40px;
    text-decoration: none;
    transition: background-color 0.3s, color 0.3s;
}

nav a:hover {
    background-color: white; 
    color: #0d7377; 
    box-shadow: 0 8px 15px rgba(0, 0, 0, 0.1); 
}

/* Main */
main {
    max-width: 1200px;
    margin: 40px auto;
    padding: 20px;
    background-color: white;
    border-radius: 10px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.05);
}

/* các section */
section {
    margin-bottom: 60px;
    padding: 20px;
    background-color: #f4f4f9;
    border-radius: 10px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.05);
    transition: 0.3s;
}

section h2 {
    font-size: 2.5rem;
    color: #13b3be;
    border-bottom: 3px solid #4CAF50;
    padding-bottom: 15px;
    margin-bottom: 30px;
    text-transform: uppercase;
    letter-spacing: 2px;
}

section p {
    font-size: 1.15rem;
    line-height: 1.9;
    margin-bottom: 20px;
    color: #666;
}

section ul {
    font-size: 1.1rem;
    line-height: 1.9;
    margin-bottom: 20px;
    color: #000;
}

section strong {
    font-size: 1.35rem;
    color: #0d7377;
}

/* Image Gallery */
.image-gallery {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-around;
    gap: 20px;
}

.image-gallery img {
    width: 80%;
    border-radius: 12px;
    box-shadow: 0 8px 15px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.image-gallery img:hover {
    transform: scale(1.035);
    box-shadow: 0 12px 20px rgba(0, 0, 0, 0.2);
}
/*điều chỉnh khoảng cách */
li {
    margin-bottom: 40px; 
    line-height: 1.6;
}
/* hình ảnh trong list */
.anhdiadiem {
    display: flex;
    justify-content: space-between;
    gap: 20px;
    margin: 20px 0;
}

.anhdiadiem img {
    width: 50%;
    border-radius: 10px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.anhdiadiem img:hover {
    transform: scale(1.023);
    box-shadow: 0 12px 20px rgba(0, 0, 0, 0.2);
}

.anhvanhoa {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin: 20px 0;
}

.anhvanhoa img {
    width: 85%;
    border-radius: 10px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

/* Footer */
footer {
    background-color: #13b3be;
    color: white;
    padding: 40px 20px;
    text-align: center;
}

.footer-container {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
}

.footer-col {
    flex: 1;
    margin: 20px;
}

.footer-col h3 {
    font-size: 1.5rem;
    margin-bottom: 20px;
}

.footer-col ul {
    list-style: none;
    padding: 0;
}

.footer-col ul li {
    margin-bottom: 10px;
}

.footer-col ul li a {
    color: white;
    text-decoration: none;
}

.footer-col ul li a:hover {
    text-decoration: underline;
}

/* Social Icons */
.social-icons a {
    margin-right: 10px;
}

.social-icons img {
    width: 24px;
}

/* Footer Bottom */
.footer-bottom {
    padding: 10px 0;
    border-top: 1px solid white;
    font-size: 0.9rem;
}

/* Back to Top Button */
.back-to-top {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background-color:#13b3be;
    color: white;
    padding: 10px 15px;
    border-radius: 50%;
    font-size: 20px;
    cursor: pointer;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.back-to-top:hover {
    background-color:#6cdf6c;
    transform: scale(1.03);
    box-shadow: 0 12px 20px rgba(0, 0, 0, 0.2);
}

/* Responsive Styles */
@media (max-width: 768px) {
    nav {
        flex-direction: column;
    }

    .image-gallery,
    .anhdiadiem,
    .anhvanhoa {
        display: flex;
        flex-direction: column;
    }

    .image-gallery img,
    .anhdiadiem img,
    .anhvanhoa img {
        width: 100%;
        margin-bottom: 10px; 
    }

    .footer-container {
        flex-direction: column;
        text-align: center;
    }

    header h1 {
        font-size: 5rem;
    }
}

@media (max-width: 480px) {
    header h1 {
        font-size: 3rem;
    }

    nav a {
        font-size: 0.9rem;
    }
}