:root {
    --primary-color: #2563eb;
    --secondary-color: #1e40af;
    --background-color: #f3f4f6;
    --text-color: #1f2937;
    --white: #ffffff;
    --success: #10b981;
    --danger: #ef4444;
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

header {
    background-color: var(--white);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    padding: 1rem 0;
    margin-bottom: 2rem;
}

header nav ul {
    list-style: none;
    display: flex;
    justify-content: flex-end;
    gap: 20px;
    padding-right: 20px;
}

.sidebar-menu {
    display: block;
    list-style: none;
    padding: 0;
}

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

nav a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
}

nav a:hover {
    color: var(--primary-color);
}

.card {
    background: var(--white);
    border-radius: 8px;
    padding: 20px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    margin-bottom: 20px;
}

.btn {
    display: inline-block;
    padding: 10px 20px;
    background-color: var(--primary-color);
    color: var(--white);
    text-decoration: none;
    border-radius: 5px;
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

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

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

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

.form-group label {
    display: block;
    margin-bottom: 5px;
    font-weight: 500;
}

.form-group input,
.form-group select {
    width: 100%;
    padding: 10px;
    border: 1px solid #d1d5db;
    border-radius: 4px;
}

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

th,
td {
    padding: 12px;
    text-align: left;
    border-bottom: 1px solid #e5e7eb;
}

th {
    background-color: #f9fafb;
}

.alert {
    padding: 10px;
    border-radius: 4px;
    margin-bottom: 15px;
}

.alert-error {
    background-color: #fee2e2;
    color: #b91c1c;
}

.alert-success {
    background-color: #d1fae5;
    color: #065f46;
}

/* Dashboard Layout */
.dashboard-grid {
    display: grid;
    grid-template-columns: 250px 1fr;
    gap: 20px;
}

.sidebar {
    background: #fff;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

.sidebar-menu {
    display: block;
    list-style: none;
    padding: 0;
}

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

.sidebar-menu a {
    display: block;
    padding: 10px;
    color: #374151;
    text-decoration: none;
    border-radius: 4px;
}

.sidebar-menu a:hover,
.sidebar-menu a.active {
    background: #eff6ff;
    color: #2563eb;
}

.form-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
}

/* Responsive Design */
@media (max-width: 768px) {
    .dashboard-grid {
        grid-template-columns: 1fr;
    }

    header nav ul {
        flex-direction: row;
        /* Keep horizontal but wrap or shrink */
        justify-content: center;
        flex-wrap: wrap;
        padding-right: 0;
    }

    .form-grid {
        grid-template-columns: 1fr;
    }

    /* Make tables scrollable manually if container is small */
    table {
        display: block;
        overflow-x: auto;
        white-space: nowrap;
    }

    .sidebar {
        margin-bottom: 20px;
    }
}