body {
    font-family: Arial, sans-serif;
    background-color: #f4f4f9;
    color: #333;
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
    align-items: center; 
}

header {
    background-color: #2c3e50;
    color: white;
    width: 100%;
    padding: 20px 0;
    text-align: center;
    position: relative;
}

header h1 {
    margin: 0;
}

#user-info {
    margin-top: 10px;
    font-size: 0.9em;
}

#logout-btn {
    margin-left: 10px;
    padding: 5px 10px;
    cursor: pointer;
}

main {
    width: 90%;
    max-width: 800px;
    margin-top: 20px;
}

section {
    background: white;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    margin-bottom: 20px;
}

.hidden {
    display: none !important;
}

.auth-box {
    text-align: center;
}

.input-group {
    margin: 10px 0;
}

input {
    padding: 10px;
    width: 80%;
    max-width: 300px;
    border: 1px solid #ccc;
    border-radius: 4px;
}

button {
    padding: 10px 20px;
    background-color: #3498db;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 1em;
}

button:hover {
    background-color: #2980b9;
}

button:disabled {
    background-color: #bdc3c7;
    cursor: not-allowed;
}

#auth-message, #game-message {
    margin-top: 15px;
    color: #e74c3c;
    font-weight: bold;
}

#generated-password {
    margin-top: 20px;
    padding: 15px;
    background-color: #e8f8f5;
    border: 1px solid #1abc9c;
    border-radius: 4px;
}

#password-display {
    font-size: 1.2em;
    color: #16a085;
    display: block;
    margin: 10px 0;
}

.switch-auth {
    margin-top: 20px;
    font-size: 0.9em;
}

.game-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

#timer {
    color: #e74c3c;
    font-weight: bold;
}

.grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
}

.bingo-cell {
    background-color: #ecf0f1;
    border: 2px solid #bdc3c7;
    border-radius: 4px;
    padding: 20px 10px;
    text-align: center;
    cursor: pointer;
    user-select: none;
    min-height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.9em;
    transition: background-color 0.2s;
}

.bingo-cell:hover {
    background-color: #e0e6ed;
}

.bingo-cell.checked {
    background-color: #2ecc71;
    color: white;
    border-color: #27ae60;
    text-decoration: line-through;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 10px;
}

th, td {
    padding: 10px;
    text-align: left;
    border-bottom: 1px solid #ddd;
}

th {
    background-color: #f8f9fa;
}

@media (max-width: 600px) {
    .grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* Dark Mode */
body.dark-mode {
    background-color: #121212;
    color: #e0e0e0;
}
body.dark-mode header {
    background-color: #1f1f1f;
    border-bottom: 1px solid #333;
}
body.dark-mode section {
    background-color: #1e1e1e;
    color: #e0e0e0;
    box-shadow: 0 2px 5px rgba(0,0,0,0.5);
}
body.dark-mode input {
    background-color: #333;
    color: #fff;
    border-color: #444;
}
body.dark-mode .bingo-cell {
    background-color: #2c2c2c;
    border-color: #444;
    color: #e0e0e0;
}
body.dark-mode .bingo-cell:hover {
    background-color: #3c3c3c;
}
body.dark-mode .bingo-cell.checked {
    background-color: #27ae60;
    color: white;
    border-color: #1e8449;
}
body.dark-mode table, body.dark-mode th, body.dark-mode td {
    border-color: #444;
}
body.dark-mode th {
    background-color: #2a2a2a;
}
body.dark-mode .admin-controls {
    background-color: #252525;
    border-color: #333;
}
body.dark-mode #generated-password {
    background-color: #1b4f42;
    border-color: #1abc9c;
}
body.dark-mode #password-display {
    color: #1abc9c;
}

#theme-toggle {
    position: absolute;
    right: 20px;
    top: 20px;
    background: none;
    border: none;
    font-size: 1.5em;
    cursor: pointer;
    padding: 0;
}
#theme-toggle:hover {
    background: none;
    transform: scale(1.1);
}