/* Root variables for light theme */
:root {
    --bg-color: #f7f7f7;
    --bg-secondary: #ffffff;
    --text-color: #333333;
    --primary-color: #007acc;
    --secondary-color: #2c3e50;
    --border-color: #e0e0e0;
    --link-color: #007acc;
    --alert-error: #e74c3c;
    --alert-warning: #f39c12;
    --alert-info: #3498db;
}

/* Override variables for dark theme */
body.dark {
    --bg-color: #1e1e1e;
    --bg-secondary: #2a2a2a;
    --text-color: #e0e0e0;
    --primary-color: #3399ff;
    --secondary-color: #141414;
    --border-color: #444444;
    --link-color: #3399ff;
    --alert-error: #e74c3c;
    --alert-warning: #f39c12;
    --alert-info: #3498db;
}

/* Global styles */
body {
    margin: 0;
    font-family: Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    min-height: 100vh;
    display: flex;
}

/* Sidebar */
.sidebar {
    width: 220px;
    background-color: var(--secondary-color);
    color: var(--text-color);
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    position: fixed;
    top: 0;
    left: 0;
    overflow-y: auto;
}

.sidebar-header {
    padding: 1rem;
    border-bottom: 1px solid var(--border-color);
}
.sidebar-header h1 {
    margin: 0;
    font-size: 1.2rem;
    color: var(--primary-color);
}
.sidebar-nav {
    flex: 1;
    display: flex;
    flex-direction: column;
}
.nav-link {
    padding: 0.8rem 1rem;
    text-decoration: none;
    color: var(--text-color);
    border-left: 4px solid transparent;
    transition: background-color 0.2s, border-color 0.2s;
}
.nav-link:hover {
    background-color: var(--bg-secondary);
    border-left-color: var(--primary-color);
}

/* Main content area */
.main-content {
    flex: 1;
    margin-left: 220px;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}
.topbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.5rem 1rem;
    background-color: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
}
.topbar .button {
    padding: 0.4rem 0.8rem;
    background-color: var(--primary-color);
    color: #fff;
    border: none;
    border-radius: 3px;
    cursor: pointer;
}
.topbar .button:hover {
    opacity: 0.9;
}
.topbar .username {
    margin-right: 1rem;
}
.logout-link {
    color: var(--link-color);
    text-decoration: none;
}

.content {
    flex: 1;
    padding: 1rem;
}
.footer {
    padding: 0.8rem 1rem;
    text-align: center;
    background-color: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
}

/* Table styles */
table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 1rem;
}
th, td {
    padding: 0.6rem;
    border: 1px solid var(--border-color);
    text-align: left;
}
th {
    background-color: var(--bg-secondary);
}
tr:nth-child(even) {
    background-color: var(--bg-secondary);
}

/* Alerts */
.alert {
    padding: 0.5rem 0.8rem;
    border-radius: 3px;
    margin-bottom: 0.5rem;
}
.alert.error {
    background-color: var(--alert-error);
    color: #fff;
}
.alert.warning {
    background-color: var(--alert-warning);
    color: #fff;
}
.alert.info {
    background-color: var(--alert-info);
    color: #fff;
}

/* Forms */
form {
    margin-bottom: 1rem;
}
label {
    display: block;
    margin-bottom: 0.2rem;
}
input[type="text"],
input[type="email"],
input[type="password"],
select,
textarea {
    width: 100%;
    padding: 0.5rem;
    margin-bottom: 0.8rem;
    border: 1px solid var(--border-color);
    border-radius: 3px;
    background-color: var(--bg-secondary);
    color: var(--text-color);
}
input[type="submit"],
button {
    padding: 0.5rem 1rem;
    background-color: var(--primary-color);
    border: none;
    border-radius: 3px;
    color: #fff;
    cursor: pointer;
}
input[type="submit"]:hover,
button:hover {
    opacity: 0.9;
}

/* Responsive adjustments */
@media (max-width: 768px) {
    .sidebar {
        width: 180px;
    }
    .main-content {
        margin-left: 180px;
    }
}

@media (max-width: 576px) {
    .sidebar {
        position: static;
        width: 100%;
        height: auto;
    }
    .main-content {
        margin-left: 0;
    }
    .topbar {
        flex-direction: column;
        align-items: flex-start;
    }
    .topbar .username {
        margin-bottom: 0.5rem;
    }
}