html, body {
    height: 100%;
    margin: 0;
}

body {
    display: flex;
    flex-direction: column;
    font-family: Arial, sans-serif;
    background-color: #d7d7d7;
}

main {
    flex: 1;
    padding: 20px;
    max-width: 1200px;
    margin: 0 auto;
}

header {
    background-color: #222;
    padding: 15px 0;
}

nav {
    display: flex;
    justify-content: center;
    gap: 30px;
}

nav a {
    color: white;
    text-decoration: none;
    font-weight: bold;
    transition: 0.3s;
}

nav a:hover {
    color: #00bcd4;
}

footer {
    text-align: center;
    padding: 15px;
    background-color: #222;
    color: white;
}

table {
    border-collapse: separate;
    border-spacing: 0;
    width: 100%;
    background-color: #fff;
    box-shadow: 0 4px 10px rgba(0,0,0,0.1);
    border-radius: 10px;
    overflow: hidden;
}

th, td {
    padding: 12px 15px;
    text-align: center;
}

th {
    background-color: #00bcd4;
    color: white;
    font-weight: bold;
    text-transform: uppercase;
}

tr:nth-child(even) td {
    background-color: #f9f9f9;
}

tr:hover td {
    background-color: #e0f7fa;
}

img {
    width: 50px;
    border-radius: 5px;
}

.back-btn {
    display: inline-block;
    padding: 10px 20px;
    background-color: #00bcd4;
    color: white;
    text-decoration: none;
    font-weight: bold;
    border-radius: 8px;
    transition: background 0.3s, transform 0.2s;
    margin-bottom: 20px;
}

.back-btn:hover {
    background-color: #0091a3;
    transform: translateY(-2px);
}

h1 {
    text-align: center;
}