:root {
    --table-header-bg: #e9ecef; /* Slightly darker grey than --table-striped-bg (#f8f9fa) */
    --card-header-gradient-start: var(--tab-active-bg);
    --card-bg: #fff;
    --card-header-bg: var(--tab-active-bg);
    --primary-color: #2c3e50;
    --secondary-color: #3498db;
    --accent-color: #4A7043;
    --roth-color: #4682B4;
    --traditional-color: #D2691E;
    --roth-spouse-color: #87CEEB;
    --traditional-spouse-color: #FFA07A;
    --tax-color: #CD5C5C;
    --brokerage-color: #9370DB;
    --body-bg: #f5f7fa;
    --shadow-color: rgba(0, 0, 0, 0.1);
    --tab-active-bg: #d3e3f3;
    --input-bg: #fff;
    --input-border: #dee2e6;
    --focus-shadow: rgba(52, 152, 219, 0.25);
    --focus-border: var(--secondary-color);
    --chart-bg: #fff;
    --table-resp-bg: #fff;
    --btn-hover: #2980b9;
    --table-bg: transparent;
    --table-striped-bg: #f8f9fa;
    --table-border-color: #dee2e6;
    --tab-border: #dee2e6;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background-color: var(--body-bg);
    color: var(--primary-color);
    padding-top: 70px; /* Space for fixed navbar */
}

.container {
    max-width: 1200px;
}

h1 {
    font-family: 'Oxanium', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    color: var(--primary-color);
}

.highlighterPen {
    border: 3px solid var(--bs-warning);
    border-radius: 4px;
    padding: 0 2px;
    display: inline-block;
}

.card {
    border: none;
    border-radius: 0.5rem;
    box-shadow: 0 2px 8px var(--shadow-color);
    background-color: var(--card-bg);
}

.card-header {
    background: linear-gradient(to right, var(--card-header-gradient-start), transparent);
    color: var(--primary-color);
    font-size: 1.1rem;
    font-weight: 600;
    padding: 10px 15px;
    border-radius: 5px 5px 0 0;
}

.accordion-item .accordion-button:not(.collapsed) {
    background: linear-gradient(to right, var(--card-header-gradient-start), transparent);
    color: var(--primary-color);
}

.accordion-button {
    font-weight: 600;
    color: var(--primary-color);
}

.accordion-button:not(.collapsed) {
    background-color: var(--tab-active-bg);
    color: var(--secondary-color);
}

.accordion-body {
    color: var(--primary-color);
}

.nav-tabs {
    white-space: nowrap;
    overflow-y: hidden; /* Prevent vertical scrollbars */
}

.nav-tabs .nav-link {
    color: var(--primary-color);
    border-radius: 0.25rem 0.25rem 0 0;
    padding: 0.5rem 0.75rem;
    font-size: 1rem;
}

.nav-tabs .nav-link.active {
    background-color: var(--tab-active-bg);
    border-color: var(--tab-border) var(--tab-border) var(--tab-active-bg);
    color: var(--secondary-color);
    font-weight: 600;
}

.nav-tabs .nav-item.disabled .nav-link {
    opacity: 0.5;
    cursor: not-allowed;
}

.form-label {
    font-weight: 500;
    color: var(--primary-color);
    margin-bottom: 0.25rem;
}

.form-control:not(textarea), .form-select {
    border-radius: 0.375rem;
    transition: border-color 0.3s ease;
    background-color: var(--input-bg);
    border: 1px solid var(--input-border);
    color: var(--primary-color);
    padding: 0.5rem 0.75rem;
    height: calc(2.25rem + 2px);
    touch-action: manipulation;
}

.form-control:focus, .form-select:focus {
    border-color: var(--focus-border);
    box-shadow: 0 0 0 0.2rem var(--focus-shadow);
}

.form-check-input {
    width: 1.25rem;
    height: 1.25rem;
    margin-top: 0.25rem;
}

.form-check-label {
    padding-left: 0.5rem;
    line-height: 1.5;
}

.spouse-field.disabled {
    opacity: 0.6;
}

.spouse-field.disabled input,
.spouse-field.disabled select {
    background-color: #e9ecef;
    cursor: not-allowed;
}

.chart-container {
    height: 400px;
    background: var(--chart-bg);
    border-radius: 0.5rem;
    padding: 1rem;
    box-shadow: 0 2px 8px var(--shadow-color);
    position: relative;
}

.btn-primary {
    background-color: var(--secondary-color);
    border-color: var(--secondary-color);
    padding: 0.75rem 1.5rem;
    font-weight: 500;
    transition: all 0.3s ease;
    font-size: 1rem;
}

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

.next-btn {
    width: 100%;
}

.regular-savings-input {
    border-left: 4px solid var(--accent-color);
}

.roth-input {
    border-left: 4px solid var(--roth-color);
}

.traditional-input {
    border-left: 4px solid var(--traditional-color);
}

.roth-spouse-input {
    border-left: 4px solid var(--roth-spouse-color);
}

.traditional-spouse-input {
    border-left: 4px solid var(--traditional-spouse-color);
}

.brokerage-input {
    border-left: 4px solid var(--brokerage-color);
}

select[multiple] {
    height: 200px;
}

.navbar {
    box-shadow: 0 2px 4px var(--shadow-color);
    padding: 0.5rem 1rem;
}

.navbar-brand {
    font-family: Audiowide;
    font-size: 1.4rem;
}

.navbar .btn-outline-primary {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.theme-switcher {
    display: flex;
    align-items: center;
    cursor: pointer;
}

[data-bs-theme="light"] .theme-switcher .bi-sun-fill {
    display: none !important;
}

[data-bs-theme="light"] .theme-switcher .bi-moon-fill {
    display: inline-block !important;
}

[data-bs-theme="dark"] .theme-switcher .bi-moon-fill {
    display: none !important;
}

[data-bs-theme="dark"] .theme-switcher .bi-sun-fill {
    display: inline-block !important;
}

@media (max-width: 992px) {
    .chart-container {
        height: 350px;
    }

    select[multiple] {
        height: 180px;
    }

    .form-control, .form-select {
        font-size: 1rem;
        padding: 0.75rem 1rem;
        height: calc(2.5rem + 2px);
    }

    .card-header {
        font-size: 1.1rem;
    }

    .nav-tabs .nav-link {
        font-size: 0.9rem;
        padding: 0.5rem 0.6rem;
    }
}

@media (max-width: 768px) {
    .chart-container {
        height: 300px;
    }

    select[multiple] {
        height: 150px;
    }

    .form-control, .form-select {
        font-size: 1rem;
        padding: 0.75rem 1rem;
    }

    .card-header {
        font-size: 1rem;
    }

    .nav-tabs .nav-link {
        font-size: 0.8rem;
        padding: 0.4rem 0.5rem;
    }
}

@media (max-width: 576px) {
    .btn-primary {
        padding: 0.6rem 1.2rem;
        font-size: 0.9rem;
    }

    .navbar {
        padding: 0.4rem 0.8rem;
    }

    .form-control, .form-select {
        font-size: 0.95rem;
        padding: 0.6rem 0.9rem;
    }

    .card-header {
        font-size: 0.95rem;
        padding: 8px 12px;
    }
}

.nav-link.active.highlight {
    animation: tabHighlight 1s ease-in-out;
}

@keyframes tabHighlight {
    0%, 100% {
        box-shadow: none;
    }
    30% {
        box-shadow: 0 0 20px var(--secondary-color);
    }
}

canvas {
    max-width: 100%;
    height: 100%;
}

[data-bs-theme="dark"] {
    --table-header-bg: #2d2d2d; /* Darker than --table-striped-bg (#333333) */
    --card-header-gradient-start: var(--tab-active-bg);
    --accordion-header-gradient-start: var(--tab-active-bg);
    --primary-color: #e0e0e0;
    --secondary-color: #66b2ff;
    --accent-color: #6b8e23;
    --roth-color: #87ceeb;
    --traditional-color: #ff8c00;
    --roth-spouse-color: #add8e6;
    --traditional-spouse-color: #ffa07a;
    --tax-color: #ff6b6b;
    --brokerage-color: #ba55d3;
    --body-bg: #1a1a1a;
    --shadow-color: rgba(255, 255, 255, 0.1);
    --card-bg: #2a2a2a;
    --card-header-bg: var(--tab-active-bg);
    --tab-active-bg: #334353;
    --input-bg: #333333;
    --input-border: #444444;
    --focus-shadow: rgba(102, 178, 255, 0.25);
    --focus-border: var(--secondary-color);
    --chart-bg: #2a2a2a;
    --table-resp-bg: #2a2a2a;
    --btn-hover: #4a90e2;
    --table-bg: #2a2a2a;
    --table-striped-bg: #333333;
    --table-border-color: #444444;
    --tab-border: #444444;
}
/* Table theming for custom datatable */
#custom .datatable {
    --bs-table-color: var(--primary-color);
    --bs-table-bg: var(--table-bg);
    --bs-table-striped-bg: var(--table-striped-bg);
    --bs-table-border-color: var(--table-border-color);
}

#custom .datatable th,
#custom .datatable td {
    color: var(--primary-color) !important;
}

#custom .datatable thead.table-light {
    --bs-table-bg: var(--table-header-bg);
    --bs-table-color: var(--primary-color);
}

#custom .datatable thead.table-light th {
    position: sticky;
    top: -1px; /* Align headers exactly with container top, accounting for potential border */
    z-index: 10;
    background-color: var(--table-header-bg);
    padding: 0.75rem; /* Increase padding for taller headers */
    line-height: 1.5; /* Ensure consistent text height */
}

#custom .table-responsive {
    background-color: var(--table-resp-bg);
    border-radius: 0.5rem;
    box-shadow: 0 2px 8px var(--shadow-color);
    padding: 0 1rem 1rem 1rem; /* Remove top padding to close gap */
    max-height: 400px;
    overflow-y: auto;
    position: relative;
    overscroll-behavior: contain;
    -webkit-overflow-scrolling: touch;
}

#custom .text-muted {
    color: var(--primary-color) !important;
}