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

body {
    min-height: 100vh;
    padding: 50px 20px;
    font-family: Arial, sans-serif;
    color: white;
    background: linear-gradient(135deg, #102a43, #155a8a);
}

h1 {
    margin-bottom: 25px;
    color: #33a9dc;
    font-size: 42px;
    text-align: center;
}

/* Nút về trang chủ */
.home-link {
    display: block;
    width: fit-content;
    margin: 0 auto 30px;
    padding: 10px 20px;
    border: 2px solid #33a9dc;
    border-radius: 8px;
    color: #33a9dc;
    font-weight: bold;
    text-decoration: none;
    transition: 0.3s;
}

.home-link:hover {
    color: white;
    background-color: #1572b6;
}

ol {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 18px;
    max-width: 900px;
    margin: auto;
    list-style-position: inside;
}

li {
    padding: 20px;
    border-left: 5px solid #1572b6;
    border-radius: 10px;
    color: #333;
    background-color: white;
    font-weight: bold;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.25);
    transition: 0.3s;
}

li:hover {
    transform: translateY(-5px);
    background-color: #a8ddf0;
    box-shadow: 0 10px 22px rgba(0, 0, 0, 0.35);
}

li a {
    color: #1572b6;
    text-decoration: none;
}

li:hover a {
    color: #102a43;
}