/* Căn giữa trang */
body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
}

/* Khung menu */
.menu {
    margin-top: 150px;
    display: flex;
    justify-content: center;
}

/* Menu chính */
.menu-list {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    background: blue;
}

/* Các mục menu */
.menu-list > li {
    position: relative;
    border-right: 1px solid white; /* phân cách */
}

/* Bỏ đường phân cách cuối */
.menu-list > li:last-child {
    border-right: none;
}

/* Link menu */
.menu-list > li > a {
    display: block;
    padding: 15px 30px;
    color: white;
    text-decoration: none;
    background: blue;
}

/* Hover menu chính */
.menu-list > li > a:hover {
    background: oldlace;
    color: black;
}

/* Menu con */
.submenu {
    list-style: none;
    margin: 0;
    padding: 0;
    position: absolute;
    top: 100%;
    left: 0;
    display: none;
    min-width: 180px;
}

/* Bài tập 1 */
/* Các item menu con */
.submenu li {
    border-bottom: 1px solid white;
}

/* Link menu con */
.submenu li a {
    display: block;
    padding: 12px 15px;
    background: blue;
    color: white;
    text-decoration: none;
}

/* Hover menu con */
.submenu li a:hover {
    background: oldlace;
    color: black;
}

/* Hiện menu con khi rê chuột */
.dropdown:hover .submenu {
    display: block;
}

/* Xóa dấu chấm và khoảng cách mặc định */
ul {
    list-style: none;
    margin: 0;
    padding: 0;
}

/* MENU CẤP 1 */
#menu {
    width: 150px;
    background: #000000;
}

/* Các mục menu */
#menu li {
    position: relative;
}

/* Link trong menu */
#menu li a {
    display: block;
    width: 150px;
    padding: 12px 15px;
    background: #000000;
    color: #FFF;
    text-decoration: none;
    border-bottom: 1px solid #FFF;
}

/* Hover menu cấp 1 */
#menu li a:hover {
    background: darkgray;
    color: #000;
}

/* MENU CẤP 2 */
#submenu1 {
    position: absolute;
    top: 0;
    left: 150px;
    display: none;
    width: max-content;
    background: #000000;
}

/* Hiện menu cấp 2 khi hover */
#menu li:hover > #submenu1 {
    display: block;
}

/* Menu cấp 2 link */
#submenu1 li a {
    width: max-content;
    min-width: 150px;
    padding: 12px 15px;
    background: #000000;
    color: #FFF;
    text-decoration: none;
    border-bottom: 1px solid #FFF;
}

/* Hover menu cấp 2 */
#submenu1 li a:hover {
    background: darkgray;
    color: #000;
}

/* MENU CẤP 3 */
#submenu2 {
    position: absolute;
    top: 0;
    left: 100%;
    display: none;
    width: max-content;
    background: #000000;
}

/* Hiện menu cấp 3 khi hover */
#submenu1 li:hover > #submenu2 {
    display: block;
}

/* Menu cấp 3 kế thừa menu cấp 2 */
#submenu2 li a {
    width: max-content;
    min-width: 150px;
    padding: 12px 15px;
    background: #000000;
    color: #FFF;
    text-decoration: none;
    border-bottom: 1px solid #FFF;
}

/* Hover menu cấp 3 */
#submenu2 li a:hover {
    background: darkgray;
    color: #000;
}

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

body {
    font-family: Arial, sans-serif;
    background: linear-gradient(to right, #dbeafe, #eff6ff);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
}

.home-container {
    width: 90%;
    max-width: 1000px;
    text-align: center;
    background: white;
    padding: 50px 30px;
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
}

.home-container h1 {
    font-size: 40px;
    color: #1e3a8a;
    margin-bottom: 10px;
}

.subtitle {
    font-size: 18px;
    color: #555;
    margin-bottom: 40px;
}

.task-list {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 25px;
}

.task-card {
    display: block;
    text-decoration: none;
    background: #2563eb;
    color: white;
    padding: 30px 20px;
    border-radius: 18px;
    transition: 0.3s;
    box-shadow: 0 10px 20px rgba(37, 99, 235, 0.2);
}

.task-card:hover {
    background: #1d4ed8;
    transform: translateY(-8px);
    box-shadow: 0 16px 28px rgba(37, 99, 235, 0.3);
}

.task-card h2 {
    font-size: 24px;
    margin-bottom: 12px;
}

.task-card p {
    font-size: 16px;
    color: #e0e7ff;
}

/* Responsive */
@media (max-width: 768px) {
    .task-list {
        grid-template-columns: 1fr;
    }

    .home-container h1 {
        font-size: 30px;
    }
}