:root {
    --sidebar-bg: #2C3E50;
    --main-bg: #f0f2f5;
    --white: #ffffff;
    --primary-blue: #0ea5e9;
    --text-dark: #1e293b;
    --text-light: #64748b;
    --success: #22c55e;
    --warning: #f59e0b;
    --danger: #ef4444;
    --border-color: #e2e8f0;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
}

body {
    background-color: var(--main-bg);
    min-height: 100vh;
    display: flex;
}

/* Sidebar Styles */
.sidebar {
    width: 260px;
    background-color: var(--sidebar-bg);
    padding: 24px 0;
    height: 100vh;
    position: fixed;
    display: flex;
    flex-direction: column;
}

.sidebar-brand {
    color: var(--white);
    font-size: 24px;
    font-weight: 600;
    padding: 0 24px;
    margin-bottom: 40px;
}

.nav-menu {
    list-style: none;
    flex-grow: 1;
}

.nav-item {
    padding: 12px 24px;
    margin: 4px 0;
}

.nav-item a {
    color: var(--white);
    text-decoration: none;
    font-size: 16px;
    opacity: 0.8;
    transition: opacity 0.3s;
    display: block;
}

.nav-item:hover a {
    opacity: 1;
}

.nav-item.active {
    background-color: rgba(255, 255, 255, 0.1);
}

.nav-item.active a {
    opacity: 1;
}

.logout-item {
    padding: 12px 24px;
    margin-top: auto;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.logout-item a {
    color: var(--white);
    text-decoration: none;
    font-size: 16px;
    opacity: 0.8;
    transition: opacity 0.3s;
    display: flex;
    align-items: center;
}

.logout-item:hover a {
    opacity: 1;
    color: var(--danger);
}

/* Main Content Styles */
.main-content {
    flex: 1;
    margin-left: 260px;
    padding: 24px;
}

.container {
    max-width: 800px;
    margin: 2rem auto;
    padding: 2rem;
    background: var(--white);
    border-radius: 10px;
    box-shadow: 0 0 20px rgba(0,0,0,0.1);
}

/* Form Styles */
.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    color: var(--text-dark);
    margin-bottom: 0.5rem;
    font-weight: 500;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 1rem;
    transition: all 0.3s ease;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-blue);
    box-shadow: 0 0 0 2px rgba(14, 165, 233, 0.1);
}

/* Button Styles */
.btn {
    padding: 0.75rem 1.5rem;
    border-radius: 4px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    border: none;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

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

.btn-secondary {
    background-color: var(--text-light);
    color: var(--white);
}

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

.btn:hover {
    opacity: 0.9;
    transform: translateY(-1px);
}

/* Message Styles */
.message {
    padding: 1rem;
    margin-bottom: 1rem;
    border-radius: 4px;
    background-color: var(--success);
    color: var(--white);
    transition: opacity 0.3s ease;
}

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

.message.warning {
    background-color: var(--warning);
}

/* Card Styles */
.card {
    background: var(--white);
    border-radius: 8px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

/* Table Styles */
.table {
    width: 100%;
    border-collapse: collapse;
}

.table th,
.table td {
    padding: 0.75rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.table th {
    font-weight: 600;
    background-color: #f8fafc;
}

/* Status Badge Styles */
.status {
    padding: 0.25rem 0.75rem;
    border-radius: 9999px;
    font-size: 0.875rem;
    font-weight: 500;
}

.status-pending {
    background-color: #fef3c7;
    color: #92400e;
}

.status-approved {
    background-color: #dcfce7;
    color: #166534;
}

.status-rejected {
    background-color: #fee2e2;
    color: #991b1b;
}

/* Responsive Design */
@media (max-width: 768px) {
    .sidebar {
        width: 200px;
    }

    .main-content {
        margin-left: 200px;
        padding: 1rem;
    }

    .container {
        margin: 1rem;
        padding: 1rem;
    }
}

@media (max-width: 640px) {
    .sidebar {
        display: none;
    }

    .main-content {
        margin-left: 0;
        width: 100%;
    }
}