:root {
    /* Color Palette - Premium Dark Theme */
    --bg-main: #0B0E14;
    --bg-card: #151A23;
    --bg-hover: #1E2532;
    
    --text-primary: #FFFFFF;
    --text-secondary: #94A3B8;
    --text-muted: #64748B;
    
    --accent-primary: #3B82F6;
    --accent-hover: #2563EB;
    --accent-glow: rgba(59, 130, 246, 0.2);
    
    --success: #10B981;
    --warning: #F59E0B;
    --danger: #EF4444;

    /* Styling vars */
    --border-color: rgba(255, 255, 255, 0.08);
    --border-radius-lg: 16px;
    --border-radius-md: 12px;
    --border-radius-sm: 8px;
    
    --shadow-sm: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 10px 15px rgba(0, 0, 0, 0.2);
    --shadow-glow: 0 0 20px var(--accent-glow);
    
    --transition-fast: 0.2s ease;
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    background-color: var(--bg-main);
    color: var(--text-primary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

.hidden {
    display: none !important;
}

#app {
    max-width: 1400px;
    margin: 0 auto;
    padding: 2.5rem 2rem 2rem 2rem;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Toast */
.toast {
    position: fixed;
    top: 24px;
    right: 24px;
    background-color: #1E293B;
    border: 1px solid var(--accent-primary);
    color: #fff;
    padding: 12px 24px;
    border-radius: var(--border-radius-sm);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.5);
    z-index: 9999;
    font-size: 0.95rem;
    display: flex;
    align-items: center;
    gap: 10px;
    animation: slideIn 0.3s ease;
}

@keyframes slideIn {
    from { transform: translateX(100%); opacity: 0; }
    to { transform: translateX(0); opacity: 1; }
}

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

.logo-container {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.logo-icon {
    width: 36px;
    height: 36px;
    color: var(--accent-primary);
}

h1 {
    font-size: 1.5rem;
    font-weight: 600;
    letter-spacing: -0.02em;
}

.sync-badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 0.8rem;
    color: var(--text-secondary);
    margin-top: 2px;
}

.status-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background-color: var(--success);
    display: inline-block;
    box-shadow: 0 0 8px var(--success);
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.6rem 1.2rem;
    border-radius: var(--border-radius-sm);
    font-size: 0.95rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
    border: none;
    font-family: inherit;
    text-decoration: none;
}

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

.btn-primary:hover {
    background-color: var(--accent-hover);
    transform: translateY(-1px);
}

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

.btn-secondary:hover {
    background-color: #2A3441;
}

.btn-icon {
    padding: 0.6rem 0.8rem;
}

.btn-large {
    padding: 1rem 2rem;
    font-size: 1.1rem;
}

/* Loading State */
.loading-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 300px;
    gap: 1rem;
    color: var(--text-secondary);
}

.spinner {
    width: 40px;
    height: 40px;
    border: 3px solid rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    border-top-color: var(--accent-primary);
    animation: spin 1s ease-in-out infinite;
}

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

/* Upload Section */
.upload-section {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 400px;
}

.upload-card {
    background-color: var(--bg-card);
    border: 1px dashed var(--border-color);
    border-radius: var(--border-radius-lg);
    padding: 4rem 3rem;
    text-align: center;
    max-width: 540px;
    width: 100%;
    transition: all var(--transition-fast);
}

.upload-card:hover {
    border-color: var(--accent-primary);
    box-shadow: var(--shadow-glow);
}

.upload-icon-wrapper {
    width: 80px;
    height: 80px;
    background-color: var(--bg-hover);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
}

.upload-icon {
    width: 40px;
    height: 40px;
    color: var(--accent-primary);
}

.upload-card h2 {
    margin-bottom: 0.5rem;
    font-size: 1.5rem;
}

.upload-card p {
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

.upload-hint {
    margin-top: 1.2rem;
    font-size: 0.85rem;
    color: var(--text-muted);
}

/* Dashboard Section */
.dashboard-section {
    display: flex;
    flex-direction: column;
    gap: 2rem;
    animation: fadeIn 0.4s ease;
}

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

/* Summary Cards */
.summary-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1.25rem;
}

.summary-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-md);
    padding: 1.25rem;
    display: flex;
    align-items: center;
    gap: 1rem;
    box-shadow: var(--shadow-sm);
    transition: transform var(--transition-fast), border-color var(--transition-fast);
}

.summary-card:hover {
    transform: translateY(-2px);
    border-color: rgba(255, 255, 255, 0.15);
}

.summary-icon {
    width: 46px;
    height: 46px;
    border-radius: var(--border-radius-sm);
    background-color: var(--bg-hover);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent-primary);
}

.summary-info h3 {
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 0.2rem;
}

.summary-value {
    font-size: 1.35rem;
    font-weight: 600;
    color: var(--text-primary);
}

/* Charts Grid */
.charts-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 1.5rem;
}

.chart-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-md);
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
}

.chart-header {
    margin-bottom: 1rem;
}

.chart-header h3 {
    font-size: 1.05rem;
    font-weight: 600;
}

.chart-container {
    position: relative;
    height: 260px;
    width: 100%;
}

/* Table Card */
.trips-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-md);
    overflow: hidden;
}

.trips-header {
    padding: 1.25rem 1.5rem;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.trips-header h3 {
    font-size: 1.15rem;
    font-weight: 600;
}

.table-subtitle {
    font-size: 0.85rem;
    color: var(--text-muted);
}

.table-container {
    overflow-x: auto;
    max-height: 600px;
}

.trips-table {
    width: 100%;
    border-collapse: collapse;
    text-align: left;
    font-size: 0.9rem;
}

.trips-table th {
    background-color: rgba(0, 0, 0, 0.2);
    padding: 0.9rem 1rem;
    font-weight: 600;
    color: var(--text-secondary);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 10;
}

.column-filter {
    display: block;
    width: 100%;
    margin-top: 0.4rem;
    padding: 0.35rem 0.5rem;
    background-color: var(--bg-hover);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    color: var(--text-primary);
    font-size: 0.8rem;
    font-family: inherit;
    outline: none;
}

.column-filter:focus {
    border-color: var(--accent-primary);
}

.trips-table td {
    padding: 0.9rem 1rem;
    border-bottom: 1px solid var(--border-color);
    color: var(--text-primary);
}

.trips-table tr:hover td {
    background-color: var(--bg-hover);
}

.address-cell {
    max-width: 200px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

@media (max-width: 768px) {
    #app {
        padding: 1rem;
    }
    .header {
        flex-direction: column;
        align-items: flex-start;
    }
    .header-actions {
        width: 100%;
        justify-content: space-between;
    }
    .charts-grid {
        grid-template-columns: 1fr;
    }
}