:root {
    /* Light Theme (Default) */
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --text-color: #1e293b;
    --text-muted: #64748b;
    --primary-color: #2563eb;
    --secondary-color: #1e40af;
    --accent-color: #3b82f6;
    --border-color: #cbd5e1;
    --input-bg: #ffffff;
    --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1);
    --transition: all 0.2s ease;
}

[data-theme="dark"] {
    /* Dark Theme */
    --bg-color: #0f172a;
    --card-bg: #1e293b;
    --text-color: #f8fafc;
    --text-muted: #94a3b8;
    --primary-color: #38bdf8;
    --secondary-color: #0ea5e9;
    --accent-color: #7dd3fc;
    --border-color: #334155;
    --input-bg: #0f172a;
    --shadow: 0 10px 15px -3px rgb(0 0 0 / 0.4);
}

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

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: var(--font-family, 'Inter', sans-serif);
    font-size: var(--font-size, 16px);
    line-height: 1.6;
    transition: background-color 0.3s, color 0.3s;
    min-height: 100vh;
    width: 100%;
}

.container {
    max-width: 1200px;
    width: 100%;
    margin: 0 auto;
    padding: 1.5rem;
}

.card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 1rem;
    padding: 2rem;
    box-shadow: var(--shadow);
}

h1, h2, h3 {
    margin-bottom: 1.5rem;
    font-weight: 800;
    color: var(--text-color);
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border-radius: 0.5rem;
    border: 1px solid transparent;
    background: var(--primary-color);
    color: #ffffff;
    cursor: pointer;
    font-weight: 600;
    transition: var(--transition);
    text-decoration: none;
    text-align: center;
}

.btn:hover {
    filter: brightness(1.1);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.2);
}

input, select, textarea, option {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    background-color: var(--input-bg);
    color: var(--text-color);
    outline: none;
    font-family: inherit;
    font-size: 0.9rem;
    transition: var(--transition);
}

select option {
    background-color: var(--card-bg);
    color: var(--text-color);
}

input:focus, select:focus, textarea:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

.form-group {
    margin-bottom: 1.5rem;
}

label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    font-size: 0.85rem;
    color: var(--text-color);
    opacity: 0.9;
}

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

th {
    text-align: left;
    padding: 1rem;
    font-weight: 700;
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
    border-bottom: 2px solid var(--border-color);
}

td {
    padding: 1rem;
    border-bottom: 1px solid var(--border-color);
}

tr:last-child td {
    border-bottom: none;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}
::-webkit-scrollbar-track {
    background: var(--bg-color);
}
::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}

/* Helper Classes */
@media (max-width: 768px) {
    .desktop-only { display: none !important; }
}
@media (min-width: 769px) {
    .mobile-only { display: none !important; }
    .mobile-nav-fixed { display: none !important; }
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 1rem;
    }

    .card {
        padding: 1.25rem;
    }

    h1 { font-size: 1.75rem !important; }
    h2 { font-size: 1.5rem !important; }
    h3 { font-size: 1.25rem !important; }

    /* Responsive Table Wrapper */
    .table-responsive {
        width: 100%;
        overflow-x: auto;
        -webkit-overflow-scrolling: touch;
        margin-bottom: 1rem;
        border-radius: 0.5rem;
    }

    table {
        min-width: 600px; /* Ensure table doesn't squish too much */
    }

    .btn {
        padding: 0.6rem 1rem;
        font-size: 0.9rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0.75rem;
    }
    
    .card {
        padding: 1rem;
    }

    input, select, .btn {
        font-size: 1rem; /* Better for mobile inputs */
    }
}