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

:root {
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --secondary: #ec4899;
    --accent: #10b981;
    --warning: #f59e0b;
    --error: #ef4444;
    
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --bg-card: #1e293b;
    
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-muted: #94a3b8;
    
    --border: #334155;
    --border-light: #475569;
    
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -1px rgba(0, 0, 0, 0.2);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.4), 0 4px 6px -2px rgba(0, 0, 0, 0.3);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.5), 0 10px 10px -5px rgba(0, 0, 0, 0.3);
    
    --radius: 16px;
    --radius-sm: 8px;
    --radius-lg: 24px;
    
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: linear-gradient(135deg, var(--bg-primary) 0%, #1a1f3a 50%, var(--bg-primary) 100%);
    background-attachment: fixed;
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    padding: 0;
    overflow-x: hidden;
}

/* Scrollbar Styling */
::-webkit-scrollbar {
    width: 10px;
}

::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
    background: var(--bg-tertiary);
    border-radius: 5px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--primary);
}

/* Layout Container */
.app-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 2rem;
    display: grid;
    grid-template-columns: 280px 1fr;
    gap: 2rem;
    min-height: 100vh;
}

/* Sidebar */
.sidebar {
    position: sticky;
    top: 2rem;
    height: fit-content;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 2rem;
    box-shadow: var(--shadow-xl);
    backdrop-filter: blur(10px);
}

.sidebar-header {
    margin-bottom: 2rem;
}

.sidebar-header h1 {
    font-size: 1.75rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 0.5rem;
}

.sidebar-header p {
    color: var(--text-muted);
    font-size: 0.875rem;
}

.stats-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1rem;
    margin-bottom: 2rem;
}

.stat-item {
    background: linear-gradient(135deg, var(--bg-tertiary) 0%, var(--bg-secondary) 100%);
    padding: 1.25rem;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    transition: var(--transition);
}

.stat-item:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow);
    border-color: var(--primary);
}

.stat-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-light);
    margin-bottom: 0.25rem;
}

.stat-label {
    font-size: 0.75rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    font-weight: 600;
}

/* Main Content */
.main-content {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

/* Navigation Tabs */
.nav-tabs {
    display: flex;
    gap: 0.5rem;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 0.5rem;
    box-shadow: var(--shadow);
}

.nav-tab {
    flex: 1;
    padding: 0.875rem 1.5rem;
    background: transparent;
    border: none;
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    font-weight: 600;
    font-size: 0.875rem;
    cursor: pointer;
    transition: var(--transition);
    position: relative;
    text-align: center;
}

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

.nav-tab.active {
    color: var(--text-primary);
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    box-shadow: var(--shadow);
}

.nav-tab.active::before {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 50%;
    transform: translateX(-50%);
    width: 40%;
    height: 2px;
    background: var(--accent);
    border-radius: 2px;
}

/* Tab Content */
.tab-panel {
    display: none;
    animation: fadeIn 0.3s ease-out;
}

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

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

/* Content Card */
.content-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 2rem;
    box-shadow: var(--shadow-xl);
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid var(--border);
}

.card-header h2 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
}

/* Buttons */
.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--radius);
    font-weight: 600;
    font-size: 0.875rem;
    cursor: pointer;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: white;
    box-shadow: var(--shadow);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    border: 1px solid var(--border);
}

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

.btn-icon {
    width: 1.25rem;
    height: 1.25rem;
}

/* Forms */
.form-container {
    background: linear-gradient(135deg, var(--bg-tertiary) 0%, var(--bg-secondary) 100%);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 2rem;
    margin-bottom: 2rem;
    animation: slideDown 0.3s ease-out;
}

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

.form-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-bottom: 1.5rem;
}

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

.form-group label {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.form-group input,
.form-group select,
.form-group textarea {
    padding: 0.875rem;
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-size: 1rem;
    transition: var(--transition);
    font-family: inherit;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.2);
}

.form-group textarea {
    resize: vertical;
    min-height: 100px;
}

.range-container {
    position: relative;
}

.range-display {
    display: flex;
    justify-content: space-between;
    margin-top: 0.5rem;
    font-size: 0.75rem;
    color: var(--text-muted);
}

.range-display span:first-child,
.range-display span:last-child {
    color: var(--text-secondary);
}

.range-display span:nth-child(2) {
    font-weight: 700;
    color: var(--primary-light);
    font-size: 1rem;
}

input[type="range"] {
    width: 100%;
    height: 8px;
    -webkit-appearance: none;
    appearance: none;
    background: var(--bg-primary);
    border-radius: 5px;
    outline: none;
    border: 1px solid var(--border);
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 20px;
    height: 20px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    cursor: pointer;
    border-radius: 50%;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

input[type="range"]::-webkit-slider-thumb:hover {
    transform: scale(1.2);
    box-shadow: var(--shadow-lg);
}

input[type="range"]::-moz-range-thumb {
    width: 20px;
    height: 20px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    cursor: pointer;
    border-radius: 50%;
    border: none;
    box-shadow: var(--shadow);
}

.form-actions {
    display: flex;
    gap: 1rem;
    margin-top: 1.5rem;
}

/* Lists */
.list-container {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.list-item {
    background: linear-gradient(135deg, var(--bg-tertiary) 0%, var(--bg-secondary) 100%);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.5rem;
    transition: var(--transition);
    animation: fadeIn 0.3s ease-out;
}

.list-item:hover {
    transform: translateX(4px);
    border-color: var(--primary);
    box-shadow: var(--shadow);
}

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

.item-date {
    font-size: 0.875rem;
    color: var(--text-muted);
}

.item-meta {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    margin-top: 1rem;
}

.meta-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.meta-badge {
    padding: 0.25rem 0.75rem;
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
}

.meta-badge.primary {
    background: rgba(99, 102, 241, 0.2);
    border-color: var(--primary);
    color: var(--primary-light);
}

.meta-badge.success {
    background: rgba(16, 185, 129, 0.2);
    border-color: var(--accent);
    color: var(--accent);
}

.meta-badge.warning {
    background: rgba(245, 158, 11, 0.2);
    border-color: var(--warning);
    color: var(--warning);
}

/* Empty States */
.empty-state {
    text-align: center;
    padding: 4rem 2rem;
    color: var(--text-muted);
}

.empty-state-icon {
    font-size: 4rem;
    margin-bottom: 1rem;
    opacity: 0.5;
}

.empty-state p {
    font-size: 1.125rem;
}

/* Loading */
.loading {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    padding: 3rem;
    color: var(--text-muted);
}

.loading::after {
    content: '';
    width: 20px;
    height: 20px;
    border: 3px solid var(--border);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

/* Messages */
.message {
    padding: 1rem 1.5rem;
    border-radius: var(--radius);
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-weight: 500;
    animation: slideDown 0.3s ease-out;
}

.message.success {
    background: rgba(16, 185, 129, 0.15);
    border: 1px solid var(--accent);
    color: var(--accent);
}

.message.error {
    background: rgba(239, 68, 68, 0.15);
    border: 1px solid var(--error);
    color: var(--error);
}

.hidden {
    display: none !important;
}

/* Responsive */
@media (max-width: 1024px) {
    .app-container {
        grid-template-columns: 1fr;
        padding: 1rem;
    }
    
    .sidebar {
        position: static;
        order: -1;
    }
    
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .nav-tabs {
        flex-wrap: wrap;
    }
    
    .nav-tab {
        flex: 1 1 calc(50% - 0.25rem);
        font-size: 0.75rem;
        padding: 0.75rem 1rem;
    }
    
    .content-card {
        padding: 1.5rem;
    }
    
    .card-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 1rem;
    }
    
    .form-grid {
        grid-template-columns: 1fr;
    }
    
    .form-actions {
        flex-direction: column;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
}