:root {
    --bg-color: #0f172a;
    --card-bg: #1e293b;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --accent-color: #3b82f6;
    --accent-hover: #2563eb;
    --danger: #ef4444;
    --success: #10b981;
    --border-color: #334155;
    --input-bg: #0f172a;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="light"] {
    --bg-color: #f1f5f9;
    --card-bg: #ffffff;
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --accent-color: #2563eb;
    --accent-hover: #1d4ed8;
    --border-color: #e2e8f0;
    --input-bg: #f8fafc;
}

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

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.6;
    transition: var(--transition);
    min-height: 100vh;
}

.app-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 3rem;
}

h1 {
    font-size: 1.875rem;
    font-weight: 700;
    letter-spacing: -0.025em;
    color: var(--text-primary);
}

.theme-toggle {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 0.5rem 1rem;
    border-radius: 0.5rem;
    cursor: pointer;
    font-weight: 500;
    transition: var(--transition);
}

.theme-toggle:hover {
    border-color: var(--accent-color);
}

/* Tabs Navigation */
.tabs-nav {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 2rem;
    overflow-x: auto;
    padding-bottom: 0.5rem;
    scrollbar-width: none;
}

.tabs-nav::-webkit-scrollbar {
    display: none;
}

.tab-btn {
    background: transparent;
    border: 1px solid transparent;
    color: var(--text-secondary);
    padding: 0.75rem 1.25rem;
    border-radius: 0.5rem;
    cursor: pointer;
    font-weight: 500;
    white-space: nowrap;
    transition: var(--transition);
}

.tab-btn:hover {
    color: var(--text-primary);
    background: var(--card-bg);
}

.tab-btn.active {
    background: var(--accent-color);
    color: white;
}

/* Main Content Area */
.tab-content {
    display: none;
    animation: fadeIn 0.4s ease-out;
}

.tab-content.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Forms */
.form-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 1rem;
    border: 1px solid var(--border-color);
    margin-bottom: 2rem;
}

.input-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

label {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
}

input, select {
    background: var(--input-bg);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 0.75rem;
    border-radius: 0.5rem;
    outline: none;
    transition: var(--transition);
}

input:focus, select:focus {
    border-color: var(--accent-color);
    box-shadow: 0 0 0 2px rgba(59, 130, 246, 0.1);
}

.button-group {
    grid-column: 1 / -1;
    display: flex;
    gap: 1rem;
    margin-top: 1rem;
}

.btn {
    padding: 0.75rem 1.5rem;
    border-radius: 0.5rem;
    cursor: pointer;
    font-weight: 600;
    border: none;
    transition: var(--transition);
}

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

.btn-primary:hover {
    background: var(--accent-hover);
}

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

.btn-secondary {
    background: var(--border-color);
    color: var(--text-primary);
}

/* Tables */
.table-container {
    background: var(--card-bg);
    border-radius: 1rem;
    border: 1px solid var(--border-color);
    overflow: hidden;
}

table {
    width: 100%;
    border-collapse: collapse;
    text-align: left;
}

th {
    background: rgba(0, 0, 0, 0.05);
    padding: 1rem;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-secondary);
    border-bottom: 1px solid var(--border-color);
}

td {
    padding: 1rem;
    font-size: 0.875rem;
    border-bottom: 1px solid var(--border-color);
}

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

tr:hover {
    background: rgba(59, 130, 246, 0.03);
}

/* Dashboard Stats */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1.5rem;
    margin-bottom: 3rem;
}

.stat-card {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 1rem;
    border: 1px solid var(--border-color);
    text-align: center;
    transition: var(--transition);
}

.stat-card:hover {
    transform: translateY(-5px);
    border-color: var(--accent-color);
}

.stat-card h3 {
    font-size: 0.875rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 0.5rem;
}

.stat-card p {
    font-size: 2rem;
    font-weight: 700;
    color: var(--accent-color);
}

.actions-cell {
    display: flex;
    gap: 0.5rem;
}

.badge {
    padding: 0.25rem 0.75rem;
    border-radius: 9999px;
    font-size: 0.75rem;
    font-weight: 600;
}

.badge-success { background: rgba(16, 185, 129, 0.1); color: var(--success); }
.badge-warning { background: rgba(245, 158, 11, 0.1); color: #f59e0b; }
.badge-danger { background: rgba(239, 68, 68, 0.1); color: var(--danger); }

@media (max-width: 768px) {
    .app-container {
        padding: 1rem;
    }
    
    header {
        flex-direction: column;
        gap: 1rem;
        align-items: flex-start;
    }
    
    .form-grid {
        grid-template-columns: 1fr;
    }
}