:root {
    --primary-color: #4CAF50;
    --primary-hover: #45a049;
    --bg-color: #f4f4f9;
    --card-bg: #ffffff;
    --text-color: #333333;
    --border-color: #dddddd;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    display: flex;
    flex-direction: column;
    align-items: center;
    min-height: 100vh;
}

nav {
    width: 100%;
    background-color: var(--primary-color);
    color: white;
    padding: 15px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

nav a {
    color: white;
    text-decoration: none;
    margin-left: 15px;
    font-weight: bold;
}

.container {
    width: 100%;
    max-width: 400px;
    margin-top: 50px;
    padding: 20px;
}

.card {
    background: var(--card-bg);
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

h2 {
    text-align: center;
    margin-bottom: 20px;
}

.form-group {
    margin-bottom: 15px;
}

.form-group label {
    display: block;
    margin-bottom: 5px;
    font-weight: bold;
}

.form-group input {
    width: 100%;
    padding: 10px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 16px;
}

.btn {
    width: 100%;
    padding: 12px;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: 4px;
    font-size: 16px;
    cursor: pointer;
    transition: background 0.3s;
    font-weight: bold;
}

.btn:hover {
    background-color: var(--primary-hover);
}

.btn:disabled {
    background-color: #9e9e9e;
    cursor: not-allowed;
}

.error-message {
    color: red;
    text-align: center;
    margin-bottom: 15px;
}

.success-message {
    color: green;
    text-align: center;
    margin-bottom: 15px;
}

/* Admin Table */
.admin-container {
    width: 100%;
    max-width: 900px;
    margin-top: 30px;
    padding: 20px;
    overflow-x: auto;
}

table {
    width: 100%;
    border-collapse: collapse;
    background: var(--card-bg);
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

th, td {
    padding: 12px 15px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

th {
    background-color: #f8f9fa;
    font-weight: bold;
}

td img {
    max-width: 100px;
    border-radius: 4px;
}

/* Preview Image in punch page */
#photo-preview {
    max-width: 100%;
    margin-top: 10px;
    border-radius: 4px;
    display: none;
}