:root {
    --sidebar-width: 260px;
    --bg-main: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --accent-blue: #38bdf8;
    --accent-green: #22c55e;
    --accent-red: #fb7185;
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --border: #334155;
}
[data-theme="light"] {
    --bg-main: #f8fafc; --bg-secondary: #ffffff; --text-main: #0f172a; --text-muted: #64748b; --border: #e2e8f0;
}
* { box-sizing: border-box; }
body { font-family: 'Inter', sans-serif; background: var(--bg-main); color: var(--text-main); margin: 0; overflow-x: hidden; }
.app-container { display: flex; width: 100%; }
.sidebar { width: var(--sidebar-width); height: 100vh; position: fixed; background: var(--bg-secondary); border-right: 1px solid var(--border); z-index: 10; }
.main-content { 
    flex: 1; 
    margin-left: var(--sidebar-width); 
    padding: 2rem; 
    max-width: calc(100vw - var(--sidebar-width));
    min-width: 0; /* important for flex items to shrink */
}
header {
    display: flex;
    justify-content: space-between;
    align-items: flex-end;
    margin-bottom: 2rem;
    flex-wrap: wrap;
    gap: 1rem;
}
.confidential-tag {
    color: var(--accent-blue);
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: 0.25rem;
}
.header-main h1 {
    margin: 0;
    font-size: 2.25rem;
    font-weight: 800;
    line-height: 1.2;
}
.top-actions {
    display: flex;
    gap: 0.75rem;
    align-items: center;
    flex-wrap: wrap;
}
.customer-grid {
    display: grid;
    grid-template-columns: 0.7fr 2fr;
    gap: 1.5rem;
    margin-bottom: 1.5rem;
}
.theme-toggle {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    color: var(--text-main);
    padding: 0.5rem;
    border-radius: 0.5rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
}
.card { background: var(--bg-secondary); border: 1px solid var(--border); border-radius: 0.75rem; padding: 1.5rem; margin-bottom: 1.5rem; transition: all 0.3s ease; }
.kpi-card:hover {
    transform: translateY(-4px);
    border-color: var(--accent-blue);
    box-shadow: 0 10px 25px -10px rgba(0, 0, 0, 0.4);
}
.section-title { font-size: 1.25rem; margin-bottom: 1.25rem; }
.fade-in { animation: fadeIn 0.5s ease-out; }
@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }

/* KPI Grid Styles */
.kpi-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1.5rem;
    margin-bottom: 1.5rem;
}
.kpi-card {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    margin-bottom: 0 !important;
    min-width: 0;
}
.kpi-value {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-main);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
.kpi-delta {
    font-size: 0.875rem;
    display: flex;
    align-items: center;
    gap: 0.25rem;
}
.delta-up { color: var(--accent-green); }
.delta-down { color: var(--accent-red); }

/* Responsive Media Queries */
@media (max-width: 1200px) {
    :root { --sidebar-width: 80px; }
    .sidebar-logo span, .logo-text, .nav-item span { display: none; }
    .main-content { margin-left: var(--sidebar-width); max-width: calc(100vw - var(--sidebar-width)); }
}

@media (max-width: 1024px) {
    .customer-grid { grid-template-columns: 1fr; }
}

@media (max-width: 768px) {
    :root { --sidebar-width: 64px; }
    .sidebar { 
        display: flex !important; 
        width: var(--sidebar-width); 
        padding: 1rem 0;
    }
    .sidebar-logo, .sidebar-footer { padding: 0; justify-content: center; }
    .sidebar-logo span, .logo-text, .nav-item span, .sidebar-footer span, .sidebar-footer .status-indicator span:last-child { 
        display: none !important; 
    }
    .nav-item { justify-content: center; padding: 0.75rem 0; }
    .main-content { 
        margin-left: var(--sidebar-width); 
        max-width: calc(100vw - var(--sidebar-width)); 
        padding: 1rem; 
    }
    .header-main h1 { font-size: 1.5rem; }
    
    header {
        display: flex;
        flex-direction: row;
        justify-content: space-between;
        align-items: flex-start;
        gap: 0.5rem;
    }
    
    .top-actions {
        flex-direction: column;
        align-items: flex-end;
        gap: 0.5rem;
    }
    
    .filter-bar {
        display: flex;
        flex-direction: column;
        align-items: flex-end;
        gap: 0.4rem;
    }
    
    .filter-select {
        width: 130px !important;
        font-size: 0.7rem !important;
        padding: 0.3rem 0.5rem !important;
    }

    .theme-toggle {
        padding: 0.4rem;
    }
    
    .kpi-grid { grid-template-columns: 1fr; }
    .card { padding: 1rem; }
}

@media (max-width: 480px) {
    .header-main h1 { font-size: 1.25rem; }
    .filter-select {
        width: 110px !important;
    }
}