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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    background-color: #f8f9fa;
    color: #333;
}

/* Header & Navigation */
header {
    background-color: #fff;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 5%;
    max-width: 1200px;
    margin: 0 auto;
}

nav .logo a {
    font-size: 1.5rem;
    font-weight: bold;
    text-decoration: none;
    color: #007bff;
}

nav ul {
    list-style: none;
    display: flex;
    gap: 1.5rem;
}

nav ul li a {
    text-decoration: none;
    color: #555;
    font-weight: 500;
    transition: color 0.3s ease;
}

nav ul li a:hover {
    color: #007bff;
}

/* Container chính */
main {
    max-width: 1200px;
    margin: 2rem auto;
    padding: 0 5%;
    min-height: 70vh;
}

/* Footer */
footer {
    text-align: center;
    padding: 1.5rem;
    background-color: #343a40;
    color: #fff;
    margin-top: auto;
}