/* General Body Styles */
body {
    font-family: 'Helvetica Neue', Arial, sans-serif;
    background-color: #f4f7f6;
    color: #333;
    margin: 0;
    padding: 0;
    line-height: 1.6;
}

/* Navbar */
.navbar {
    background-color: #2c3e50;
    padding: 1rem 0;
    text-align: center;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.nav-link {
    color: #fff;
    text-decoration: none;
    padding: 0.8rem 1.5rem;
    margin: 0 0.5rem;
    border-radius: 5px;
    transition: background-color 0.3s;
}

.nav-link:hover {
    background-color: #34495e;
}

/* Container */
.container {
    max-width: 960px;
    margin: 2rem auto;
    padding: 2rem;
    background-color: #fff;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

/* Header */
h1, h2, h3 {
    color: #2c3e50;
    margin-bottom: 1rem;
}

h1 {
    font-size: 2.5rem;
    border-bottom: 2px solid #3498db;
    padding-bottom: 0.5rem;
}

h2 {
    font-size: 2rem;
}

/* Paragraphs and Links */
p {
    margin-bottom: 1rem;
}

a {
    color: #3498db;
    text-decoration: none;
    transition: color 0.3s;
}

a:hover {
    color: #2980b9;
}

/* Buttons */
.btn {
    display: inline-block;
    background-color: #3498db;
    color: #fff;
    padding: 10px 20px;
    border-radius: 5px;
    text-align: center;
    cursor: pointer;
    transition: background-color 0.3s;
    border: none;
}

.btn:hover {
    background-color: #2980b9;
}

.btn-danger {
    background-color: #e74c3c;
}

.btn-danger:hover {
    background-color: #c0392b;
}

/* Forms */
form {
    margin-top: 1.5rem;
}

input[type="text"],
input[type="password"],
input[type="email"],
textarea {
    width: 100%;
    padding: 10px;
    margin-bottom: 1rem;
    border: 1px solid #ddd;
    border-radius: 4px;
    box-sizing: border-box; /* Important */
}

/* Tables */
table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 1.5rem;
}

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

th {
    background-color: #3498db;
    color: white;
}

tr:nth-child(even) {
    background-color: #f2f2f2;
}

/* Footer */
.footer {
    text-align: center;
    margin-top: 2rem;
    padding: 1rem;
    color: #777;
    font-size: 0.9em;
}

/* Pop-up Modal */
.popup-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.6);
    z-index: 1000;
    justify-content: center;
    align-items: center;
}

.popup-content {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    width: 90%;
    max-width: 500px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.3);
}

#popup-error {
    color: #e74c3c;
    margin-bottom: 1rem;
}

#popup-example {
    color: #777;
    font-size: 0.9em;
    margin-top: -0.5rem;
    margin-bottom: 1rem;
}

/* Flash Messages */
.flash {
    padding: 1rem;
    margin-bottom: 1rem;
    border-radius: 4px;
}
.flash.success { background-color: #d4edda; color: #155724; }
.flash.danger { background-color: #f8d7da; color: #721c24; }
.flash.info { background-color: #d1ecf1; color: #0c5460; }
.flash.warning { background-color: #fff3cd; color: #856404; }