/* Common reset and body */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #2c3e50;
    background-color: #ecf0f1;
}

/* Navbar / Header */
.navbar {
    background: linear-gradient(135deg, #2c3e50 0%, #34495e 100%);
    padding: 0;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 32px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 28.8px;
    font-weight: bold;
    color: #ffffff;
}

.logo i {
    font-size: 32px;
    color: #3498db;
}

.nav-menu ul {
    display: flex;
    list-style: none;
    gap: 32px;
}

.nav-link {
    color: #ffffff;
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
    padding: 8px 0;
}

.nav-link:hover {
    color: #3498db;
    border-bottom: 2px solid #3498db;
}

/* Table Section */
.table-section {
    max-width: 900px;
    margin: 30px auto;
    background: white;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 3px 8px rgba(0,0,0,0.1);
}

.table-section h2 {
    text-align: center;
    margin-bottom: 20px;
    color: #34495e;
}

table {
    width: 100%;
    border-collapse: collapse;
}

thead {
    background: #34495e;
    color: white;
}

th, td {
    padding: 12px 15px;
    border-bottom: 1px solid #ddd;
    text-align: center;
}


td.available {
    color: green;
    font-weight: bold;
}

td.issued {
    color: red;
    font-weight: bold;
}

button {
    padding: 6px 12px;
    border-radius: 5px;
    border: none;
    cursor: pointer;
    font-weight: bold;
}

button:hover {
    opacity: 0.85;
}

button:active {
    transform: translateY(1px);
}

button.issue {
    background-color: #3498db;
    color: #fff;
}

button.return {
    background-color: #e74c3c;
    color: #fff;
}

/* Footer */
footer {
    background-color: #1a252f;
    color: #ffffff;
    padding: 32px;
    text-align: center;
    margin-top: 48px;
}

/* Responsive */
@media (max-width: 768px) {
    .nav-menu ul {
        flex-direction: column;
        gap: 16px;
    }
}