* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
}

.screen {
    display: none;
}

.screen.active {
    display: flex;
}

/* Login Screen */
#loginScreen {
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

.login-container {
    background: white;
    padding: 40px;
    border-radius: 16px;
    box-shadow: 0 20px 60px rgba(0,0,0,0.3);
    width: 100%;
    max-width: 400px;
}

.login-container h1 {
    text-align: center;
    margin-bottom: 30px;
    color: #333;
}

.login-container form {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.login-container input {
    padding: 12px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 16px;
}

.login-container button {
    padding: 14px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.2s;
}

.login-container button:hover {
    transform: translateY(-2px);
}

.error {
    color: #ef4444;
    text-align: center;
    margin-top: 10px;
}

.success {
    color: #10b981;
    text-align: center;
    margin-top: 10px;
}

/* Dashboard Screen */
#dashboardScreen {
    min-height: 100vh;
}

.sidebar {
    width: 250px;
    background: white;
    padding: 30px 0;
    box-shadow: 2px 0 10px rgba(0,0,0,0.1);
}

.sidebar h2 {
    padding: 0 20px;
    margin-bottom: 30px;
    color: #333;
}

.sidebar ul {
    list-style: none;
}

.sidebar li {
    margin-bottom: 5px;
}

.sidebar a {
    display: block;
    padding: 12px 20px;
    color: #666;
    text-decoration: none;
    transition: all 0.3s;
}

.sidebar a:hover,
.sidebar a.active {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.content {
    flex: 1;
    padding: 40px;
    overflow-y: auto;
}

.page {
    display: none;
}

.page.active {
    display: block;
}

.content h1 {
    color: white;
    margin-bottom: 30px;
    font-size: 32px;
}

/* Stats Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.stat-card {
    background: white;
    padding: 30px;
    border-radius: 16px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
}

.stat-card h3 {
    color: #666;
    font-size: 14px;
    margin-bottom: 10px;
    text-transform: uppercase;
}

.stat-value {
    font-size: 36px;
    font-weight: bold;
    color: #667eea;
}

/* Forms */
.config-form,
.notification-form {
    background: white;
    padding: 30px;
    border-radius: 16px;
    max-width: 600px;
}

.config-form h3 {
    margin: 20px 0 15px 0;
    color: #333;
}

.config-form h3:first-child {
    margin-top: 0;
}

.config-form label,
.notification-form label {
    display: block;
    margin-bottom: 15px;
    color: #333;
}

.config-form input,
.config-form textarea,
.notification-form input,
.notification-form textarea {
    width: 100%;
    padding: 10px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    margin-top: 5px;
    font-size: 14px;
}

.config-form input[type="checkbox"] {
    width: auto;
    margin-right: 8px;
}

.config-form textarea,
.notification-form textarea {
    min-height: 100px;
    resize: vertical;
}

.config-form button,
.notification-form button {
    margin-top: 20px;
    padding: 14px 30px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.2s;
}

.config-form button:hover,
.notification-form button:hover {
    transform: translateY(-2px);
}

/* Users Table */
#usersTable {
    background: white;
    padding: 20px;
    border-radius: 16px;
    overflow-x: auto;
}

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

th, td {
    padding: 12px;
    text-align: left;
    border-bottom: 1px solid #e0e0e0;
}

th {
    background: #f9fafb;
    font-weight: 600;
    color: #333;
}

tr:hover {
    background: #f9fafb;
}