:root {
    --primary-color: #2563eb;
    --secondary-color: #f3f4f6;
    --text-primary: #111827;
    --text-secondary: #6b7280;
    --border-color: #e5e7eb;
}

body {
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
}

input, textarea {
    -webkit-user-select: text;
    -moz-user-select: text;
    -ms-user-select: text;
    user-select: text;
}

.btn {
    padding: 0.75rem 1.25rem;
    border-radius: 0.5rem;
    font-weight: 500;
    transition: all 0.2s;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
    border: none;
    font-size: 1rem;
    min-height: 44px;
}

@media (min-width: 1024px) {
    .btn {
        font-size: 1.1rem;
        padding: 0.875rem 1.5rem;
        min-height: 48px;
    }
}

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

.btn-primary:hover {
    opacity: 0.9;
}

.btn-secondary {
    background-color: #e5e7eb;
    color: #374151;
}

.btn-danger {
    background-color: #ef4444;
    color: white;
}

.input-field {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: 0.5rem;
    background: white;
    font-size: 1rem;
    min-height: 44px;
}

.input-field:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

@media (min-width: 1024px) {
    .input-field {
        font-size: 1.1rem;
        padding: 0.875rem 1.125rem;
        min-height: 48px;
    }
}

.card {
    background: white;
    border-radius: 0.5rem;
    box-shadow: 0 1px 2px rgba(0,0,0,0.05);
    border: 1px solid var(--border-color);
    padding: 1.5rem;
}

.data-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.875rem;
}

@media (max-width: 768px) {
    .data-table {
        font-size: 0.75rem;
    }
    
    .data-table th,
    .data-table td {
        padding: 0.5rem;
    }
}

.data-table {
    font-size: 0.875rem;
}

@media (max-width: 768px) {
    .data-table {
        font-size: 0.75rem;
    }
    
    .data-table th,
    .data-table td {
        padding: 0.5rem !important;
    }
}

.data-table th {
    background: #f9fafb;
    padding: 0.75rem 1rem;
    text-align: left;
    font-size: 0.875rem;
    font-weight: 700;
    color: #1f2937;
    border-bottom: 2px solid #e5e7eb;
}

.data-table td {
    padding: 0.75rem 1rem;
    font-size: 0.875rem;
    color: #374151;
    border-bottom: 1px solid #f3f4f6;
    font-weight: 500;
}

.nav-item {
    width: 100%;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1rem;
    border-radius: 0.5rem;
    margin-bottom: 0.5rem;
    transition: all 0.2s;
    cursor: pointer;
    border: none;
    background: transparent;
    color: #374151;
    text-align: left;
}

.nav-item:hover {
    background: #f3f4f6;
}

.nav-item.active {
    background: var(--primary-color);
    color: white;
}

#nav-menu {
    max-height: calc(100vh - 120px);
    overflow-y: auto;
    overflow-x: hidden;
}

#nav-menu::-webkit-scrollbar {
    width: 6px;
}

#nav-menu::-webkit-scrollbar-track {
    background: #f1f1f1;
}

#nav-menu::-webkit-scrollbar-thumb {
    background: #888;
    border-radius: 3px;
}

#nav-menu::-webkit-scrollbar-thumb:hover {
    background: #555;
}

/* Dark Mode Styles */
body.dark-mode {
    background-color: #1a202c;
    color: #e2e8f0;
}

body.dark-mode .card {
    background-color: #2d3748;
    border-color: #4a5568;
}

body.dark-mode .input-field {
    background-color: #2d3748;
    border-color: #4a5568;
    color: #e2e8f0;
}

body.dark-mode .btn-primary {
    background-color: #4299e1;
}

body.dark-mode .data-table th {
    background-color: #2d3748;
    color: #e2e8f0;
}

body.dark-mode .data-table td {
    border-color: #4a5568;
    color: #e2e8f0;
}

body.dark-mode aside {
    background-color: #2d3748;
    border-color: #4a5568;
}

body.dark-mode #main-content {
    background-color: #1a202c;
}