:root {
    --slate-50: #f8fafc;
    --slate-100: #f1f5f9;
    --slate-200: #e2e8f0;
    --slate-300: #cbd5e1;
    --slate-500: #64748b;
    --slate-700: #334155;
    --slate-800: #1e293b;
    --slate-900: #0f172a;
    
    --indigo-500: #6366f1;
    --indigo-600: #4f46e5;
    
    --emerald-500: #10b981;
    --emerald-600: #059669;
    
    --rose-500: #f43f5e;
    --rose-600: #e11d48;

    --bg-color: var(--slate-100);
    --sidebar-bg: #ffffff;
    --card-bg: #ffffff;
    --text-primary: var(--slate-900);
    --text-secondary: var(--slate-700);
    --border-color: var(--slate-200);

    --radius: 8px;
    --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

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

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.5;
}

.app-container {
    display: grid;
    grid-template-columns: 400px 1fr;
    grid-template-areas: 
        "sidebar metrics"
        "sidebar main";
    min-height: calc(100vh - 70px);
}

/* Sidebar */
.sidebar {
    grid-area: sidebar;
    background-color: var(--sidebar-bg);
    border-right: 1px solid var(--border-color);
    padding: 1.5rem;
    overflow-y: auto;
    position: sticky;
    top: 70px;
    height: calc(100vh - 70px);
    box-shadow: 2px 0 5px rgba(0,0,0,0.02);
    z-index: 10;
}

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

.sidebar header h1 {
    font-size: 1.5rem;
    color: var(--slate-900);
    font-weight: 700;
    margin-bottom: 0.25rem;
}

.sidebar header p {
    color: var(--slate-700);
    font-size: 0.875rem;
}

.control-group {
    margin-bottom: 2rem;
}

.control-group h3 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--slate-800);
}

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

.section-header h3 {
    margin-bottom: 0;
}

/* Inputs */
.input-group {
    margin-bottom: 1rem;
}

.input-group label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 0.25rem;
    color: var(--slate-700);
}

input[type="number"],
input[type="text"],
select {
    width: 100%;
    padding: 0.5rem 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    font-size: 0.875rem;
    font-family: inherit;
    transition: all 0.2s;
    background-color: #fafafa;
}

input:focus,
select:focus {
    outline: 2px solid var(--indigo-500);
    outline-offset: 2px;
    border-color: var(--indigo-500);
    background-color: #fff;
}

/* Ledger Items */
#ledgerContainer {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.ledger-item {
    background: var(--slate-50);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    padding: 1rem;
    position: relative;
    box-shadow: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    transition: transform 0.2s, box-shadow 0.2s;
}

.ledger-item:hover {
    box-shadow: var(--shadow);
    transform: translateY(-1px);
}

.ledger-item-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.75rem;
}

.ledger-item-header input {
    font-weight: 600;
    width: calc(100% - 30px);
    border-color: transparent;
    background: transparent;
    padding: 0.25rem 0;
    font-size: 1rem;
}

.ledger-item-header input:focus {
    border-color: var(--indigo-500);
    background: #fff;
    padding: 0.25rem 0.5rem;
}

.btn-delete {
    background: transparent;
    border: none;
    color: var(--rose-500);
    cursor: pointer;
    font-size: 1.25rem;
    line-height: 1;
    padding: 0.25rem;
    opacity: 0.6;
    transition: opacity 0.2s, color 0.2s;
}
.btn-delete:hover {
    color: var(--rose-600);
    opacity: 1;
}

.ledger-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0.75rem;
    margin-bottom: 0.75rem;
}
.ledger-row:last-child {
    margin-bottom: 0;
}

.ledger-row label {
    font-size: 0.75rem;
    color: var(--slate-500);
    margin-bottom: 0.25rem;
    display: block;
}

/* Buttons */
button {
    cursor: pointer;
    font-family: inherit;
    transition: all 0.2s;
}

.btn-small {
    background-color: var(--slate-200);
    color: var(--slate-800);
    border: none;
    padding: 0.25rem 0.75rem;
    border-radius: 4px;
    font-size: 0.75rem;
    font-weight: 500;
}
.btn-small:hover {
    background-color: var(--slate-300);
}

.btn-primary {
    background-color: var(--indigo-600);
    color: white;
    border: none;
    padding: 0.5rem 1rem;
    border-radius: var(--radius);
    font-weight: 500;
    box-shadow: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    text-decoration: none;   
}
.btn-primary:hover {
    background-color: var(--indigo-500);
    box-shadow: var(--shadow);
}

/* Main Content */
.main-content {
    grid-area: main;
    padding: 2rem;
    background-color: transparent;
}

.main-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
}
.main-header h2 {
    font-weight: 600;
    color: var(--slate-900);
}

.dashboard-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
    margin-bottom: 2rem;
}
.dashboard-grid .full-width {
    grid-column: 1 / -1;
}
.dashboard-grid .half-width {
    grid-column: span 1;
}

.card {
    background: var(--card-bg);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 1.5rem;
    border: 1px solid var(--border-color);
}

.chart-card {
    min-height: 400px;
    position: relative;
}

.summary-card h3 {
    margin-bottom: 1rem;
    color: var(--slate-800);
    font-weight: 600;
}

.summary-text {
    font-size: 1.125rem;
    line-height: 1.75;
    color: var(--slate-700);
}
.summary-text strong {
    color: var(--slate-900);
    font-weight: 600;
}

.metrics-grid {
    grid-area: metrics;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    padding: 2rem 2rem 0 2rem; /* align with main-content padding */
}

.metric-card {
    background: var(--card-bg);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 1.5rem;
    border: 1px solid var(--border-color);
    text-align: center;
    transition: transform 0.2s;
}
.metric-card:hover {
    transform: translateY(-2px);
}

.metric-card h4 {
    color: var(--slate-500);
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 0.75rem;
}

.metric-value {
    font-size: 2.25rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    letter-spacing: -0.02em;
}

.metric-margin {
    font-size: 0.875rem;
    font-weight: 500;
}

.vendor-value { color: var(--emerald-600); }
.platform-value { color: var(--indigo-600); }
.neutral-value { color: var(--slate-800); }

.alert {
    background-color: var(--rose-500);
    color: white;
    padding: 1rem 1.25rem;
    border-radius: var(--radius);
    margin-bottom: 1.5rem;
    font-weight: 500;
    box-shadow: 0 4px 6px -1px rgba(225, 29, 72, 0.2);
    display: flex;
    align-items: center;
}

/* Animations */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(5px); }
    to { opacity: 1; transform: translateY(0); }
}

.ledger-item {
    animation: fadeIn 0.3s ease-out;
}

/* Tooltips */
.label-with-info {
    display: flex;
    align-items: center;
    gap: 0.375rem;
    margin-bottom: 0.25rem;
}
.label-with-info label,
.label-with-info h4 {
    margin-bottom: 0 !important;
}
.info-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background-color: var(--slate-300);
    color: var(--slate-800);
    font-size: 11px;
    font-weight: 700;
    font-style: italic;
    cursor: help;
    position: relative;
    font-family: Georgia, serif;
}
.info-icon:hover::after {
    content: attr(data-tooltip);
    position: absolute;
    bottom: 150%;
    left: 50%;
    transform: translateX(-50%);
    background-color: var(--slate-800);
    color: var(--slate-50);
    padding: 0.5rem 0.75rem;
    border-radius: 4px;
    font-size: 0.75rem;
    font-weight: 400;
    font-family: 'Inter', sans-serif;
    white-space: normal;
    width: max-content;
    max-width: 220px;
    z-index: 100;
    box-shadow: var(--shadow);
    pointer-events: none;
    text-align: center;
    line-height: 1.4;
}
.info-icon:hover::before {
    content: '';
    position: absolute;
    bottom: 100%;
    left: 50%;
    transform: translateX(-50%);
    border-width: 5px;
    border-style: solid;
    border-color: var(--slate-800) transparent transparent transparent;
    z-index: 100;
    pointer-events: none;
}

/* Responsive Design */
@media (max-width: 992px) {
    .app-container {
        grid-template-columns: 1fr;
        grid-template-areas: 
            "metrics"
            "sidebar"
            "main";
    }

    .metrics-grid {
        position: sticky;
        top: 60px; /* Assuming navbar is ~60-70px */
        z-index: 40;
        background: rgba(248, 250, 252, 0.95);
        backdrop-filter: blur(8px);
        padding: 0.75rem 0.5rem;
        margin: 0;
        border-bottom: 1px solid var(--border-color);
        box-shadow: 0 4px 6px -1px rgb(0 0 0 / 0.05);
        
        /* Force compact 3-column layout */
        grid-template-columns: repeat(3, 1fr);
        gap: 0.5rem;
    }
    
    .metrics-grid .metric-card {
        padding: 0.5rem;
        border-radius: 6px;
        box-shadow: none;
        border: 1px solid var(--slate-200);
    }
    
    .metrics-grid .metric-card h4 {
        font-size: 0.75rem;
        line-height: 1.1;
        margin-bottom: 0.25rem;
    }
    
    .metrics-grid .metric-card .metric-value {
        font-size: 1rem;
    }
    
    .metrics-grid .metric-card .metric-margin {
        font-size: 0.65rem;
    }
    
    .sidebar {
        height: auto;
        position: static;
        border-right: none;
        border-bottom: 1px solid var(--border-color);
        box-shadow: none;
    }
    
    .dashboard-grid {
        grid-template-columns: 1fr;
    }
    .dashboard-grid .half-width {
        grid-column: 1 / -1;
    }
}

@media (max-width: 576px) {
    .ledger-row {
        grid-template-columns: 1fr;
    }

    .main-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 1rem;
    }

    .main-content {
        padding: 1.5rem 1rem;
    }

    .sidebar {
        padding: 1.5rem 1rem;
    }
    
    .chart-card {
        min-height: 300px;
    }
    
    .app-container {
        display: block;
    }
}

/* ==========================================================================
   Landing Page Styles
   ========================================================================== */

/* Typography & Utilities */
.text-indigo { color: var(--indigo-500); }
.text-center { text-align: center; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 1.5rem; }
.container-fluid { max-width: 1600px; margin: 0 auto; padding: 0 1.5rem; }
.bg-slate { background-color: var(--slate-50); border-top: 1px solid var(--border-color); border-bottom: 1px solid var(--border-color); }
.shadow-container { box-shadow: var(--shadow); border-radius: var(--radius); overflow: hidden; background: var(--bg-color); border: 1px solid var(--border-color); }
.btn-large { padding: 0.75rem 1.5rem; font-size: 1.125rem; }

/* Navbar */
.navbar {
    position: sticky;
    top: 0;
    z-index: 50;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
}
.nav-brand { font-size: 1.5rem; font-weight: 700; color: var(--slate-900); }
.nav-links { display: flex; list-style: none; gap: 2rem; }
.nav-links a { text-decoration: none; color: var(--slate-700); font-weight: 500; transition: color 0.2s; }
.nav-links a:hover { color: var(--indigo-500); }

/* Hero Banner */
.hero-banner {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
    max-width: 1200px;
    margin: 4rem auto;
    padding: 0 1.5rem;
}
.hero-content h1 {
    font-size: 3.5rem;
    line-height: 1.2;
    font-weight: 800;
    margin-bottom: 1.5rem;
    background: -webkit-linear-gradient(45deg, var(--indigo-600), var(--emerald-500));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}
.hero-content p {
    font-size: 1.25rem;
    color: var(--slate-700);
    margin-bottom: 2rem;
    line-height: 1.6;
}
.floating-svg {
    width: 100%;
    height: auto;
    animation: float 6s ease-in-out infinite;
}
@keyframes float {
    0% { transform: translateY(0px); }
    50% { transform: translateY(-20px); }
    100% { transform: translateY(0px); }
}

/* Sections */
.landing-section { padding: 5rem 0; }
.landing-section h2 { font-size: 2.5rem; font-weight: 700; color: var(--slate-900); margin-bottom: 1rem; }
.section-subtitle { font-size: 1.125rem; color: var(--slate-700); margin-bottom: 3rem; max-width: 600px; margin-left: auto; margin-right: auto; }

/* Grids */
.about-grid, .features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    margin-top: 3rem;
}
.about-card, .feature-card {
    background: #fff;
    padding: 2rem;
    border-radius: var(--radius);
    box-shadow: 0 1px 3px rgba(0,0,0,0.05);
    border: 1px solid var(--border-color);
    transition: transform 0.2s, box-shadow 0.2s;
}
.about-card:hover, .feature-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow);
}
.about-card .icon { font-size: 2.5rem; margin-bottom: 1rem; }
.about-card h3, .feature-card h3 { font-size: 1.25rem; color: var(--slate-900); margin-bottom: 1rem; }
.about-card p, .feature-card p { color: var(--slate-700); line-height: 1.6; }

/* FAQ */
.faq-accordion { max-width: 800px; margin: 3rem auto 0; }
.faq-item {
    background: #fff;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    margin-bottom: 1rem;
    overflow: hidden;
}
.faq-item summary {
    padding: 1.25rem;
    font-weight: 600;
    cursor: pointer;
    background: var(--slate-50);
    list-style: none;
    position: relative;
}
.faq-item summary::after {
    content: '+';
    position: absolute;
    right: 1.25rem;
    font-size: 1.25rem;
    transition: transform 0.2s;
}
.faq-item[open] summary::after { transform: rotate(45deg); }
.faq-item p { padding: 1.25rem; color: var(--slate-700); border-top: 1px solid var(--border-color); }

/* Core Tool Adjustments */
.tool-section { padding: 2rem 0 5rem; }
.tool-wrapper { padding: 0 2rem; }
/* Fix sidebar stickiness under the new navbar */
.sidebar { top: 70px; height: calc(100vh - 70px); }

/* Footer */
.footer {
    background: var(--slate-900);
    color: var(--slate-300);
    padding: 4rem 0 2rem;
}
.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--slate-800);
    padding-bottom: 2rem;
    margin-bottom: 2rem;
}
.footer-brand { font-size: 1.5rem; font-weight: 700; color: #fff; }
.footer-links { display: flex; gap: 1.5rem; }
.footer-links a { color: var(--slate-300); text-decoration: none; transition: color 0.2s; }
.footer-links a:hover { color: #fff; }
.footer-copy { font-size: 0.875rem; color: var(--slate-500); }

.footer-copy a { font-size: 0.875rem; color: var(--slate-200); }


/* Responsive adjustments for Landing Page */
@media (max-width: 992px) {
    .hero-banner { grid-template-columns: 1fr; text-align: center; gap: 2rem; }
    .hero-content h1 { font-size: 2.75rem; }
    .about-grid, .features-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 768px) {
    .navbar { padding: 1rem; }
    .nav-links { display: none; /* simple mobile hide for now, standard practice */ }
    .hero-content h1 { font-size: 2.25rem; }
    .about-grid, .features-grid { grid-template-columns: 1fr; }
    .footer-content { flex-direction: column; gap: 1.5rem; }
    .tool-wrapper { padding: 0 1rem; }
}