:root {
    --bg-page: #f4f7f6;
    --surface: #ffffff;
    --primary-color: #7cb9a8;
    --primary-hover: #5a9e8a;
    --accent-color: #d1e7dd;
    --positive-color: #48bb78;
    --negative-color: #e53e3e;

    --text-main: #2d3748;
    --text-muted: #718096;

    --card-border: #e2e8f0;
    --card-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);

    --font-family: 'Outfit', sans-serif;
    --transition: all 0.2s ease;
}

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

body {
    font-family: var(--font-family);
    background-color: var(--bg-page);
    color: var(--text-main);
    min-height: 100vh;
    padding: 1rem;
}

/* Container */
.calculator-container {
    max-width: 1400px;
    margin: 0 auto;
}

/* Header */
.header {
    background: linear-gradient(to right, #ffffff, #f8fafc);
    border-bottom: 1px solid var(--card-border);
    margin-bottom: 2rem;
    padding: 1.25rem 2rem;
    border-radius: 0 0 16px 16px;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1360px;
    margin: 0 auto;
}

.brand h1 {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-dark);
    margin: 0;
    line-height: 1.2;
}

.brand h1 .accent {
    color: var(--primary-color);
}

.slogan {
    color: var(--text-muted);
    font-size: 0.85rem;
    margin: 0.25rem 0 0 0;
    font-weight: 400;
    letter-spacing: 0.2px;
}

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

.reset-btn {
    background: white;
    border: 1px solid #e2e8f0;
    color: #64748b;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    font-size: 0.85rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    gap: 0.4rem;
}

.reset-btn:hover {
    background: #f1f5f9;
    border-color: #cbd5e1;
    color: var(--negative-color);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

/* Grid Layout */
.layout-grid {
    display: grid;
    grid-template-columns: 340px 1fr;
    gap: 2rem;
    align-items: start;
}

/* Sidebar */
.sidebar {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

/* Control Panels */
.control-panel {
    background: var(--surface);
    border: 1px solid var(--card-border);
    border-radius: 12px;
    padding: 1.25rem;
    box-shadow: var(--card-shadow);
}

.control-panel h3 {
    font-size: 0.85rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 1rem;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

/* Input Groups */
.input-group {
    margin-bottom: 0.9rem;
}

.input-group:last-child {
    margin-bottom: 0;
}

.input-group label {
    display: block;
    margin-bottom: 0.3rem;
    color: var(--text-main);
    font-size: 0.85rem;
    font-weight: 500;
}

.input-group label small {
    color: var(--text-muted);
    font-weight: 400;
}

/* Input Rows */
.input-row {
    display: flex;
    gap: 0.75rem;
    align-items: flex-start;
}

.input-row.two-col>* {
    flex: 1;
    min-width: 0;
}

/* Input Wrappers */
.input-wrapper,
.select-wrapper {
    display: flex;
    align-items: center;
    gap: 0.4rem;
}

.input-wrapper input,
.select-wrapper select {
    flex: 1;
    padding: 0.6rem;
    background: #f8fafc;
    border: 1px solid var(--card-border);
    border-radius: 8px;
    color: var(--text-main);
    font-family: var(--font-family);
    font-size: 0.95rem;
    outline: none;
    transition: var(--transition);
}

.input-wrapper input:focus,
.select-wrapper select:focus {
    border-color: var(--primary-color);
    background: #fff;
    box-shadow: 0 0 0 3px var(--accent-color);
}

.currency-symbol,
.unit-symbol {
    color: var(--text-muted);
    font-weight: 500;
    font-size: 0.9rem;
    white-space: nowrap;
}

/* Plain inputs */
input[type="number"],
input[type="date"],
select {
    width: 100%;
    padding: 0.6rem;
    background: #f8fafc;
    border: 1px solid var(--card-border);
    border-radius: 8px;
    color: var(--text-main);
    font-family: var(--font-family);
    font-size: 0.9rem;
    outline: none;
    transition: var(--transition);
}

input:focus,
select:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px var(--accent-color);
}

/* Hide number spinners */
input[type=number]::-webkit-inner-spin-button,
input[type=number]::-webkit-outer-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

/* Select styling */
.select-wrapper::after {
    content: '▼';
    font-size: 0.6rem;
    color: var(--text-muted);
    position: absolute;
    right: 0.8rem;
    pointer-events: none;
}

.select-wrapper select {
    appearance: none;
    cursor: pointer;
    padding-left: 0.6rem;
}

/* Toggle Buttons */
.toggle-group {
    display: flex;
    gap: 0;
    border-radius: 8px;
    overflow: hidden;
    border: 1px solid var(--card-border);
}

.conditional-section {
    background: #f8fafc;
    border: 1px solid #e2e8f0;
    border-radius: 8px;
    padding: 1rem;
    margin-top: 0.5rem;
    margin-bottom: 1rem;
    animation: slideDown 0.3s ease-out;
}

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

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.muted-label {
    display: block;
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-top: 0.25rem;
}

.toggle-btn {
    flex: 1;
    padding: 0.5rem 1rem;
    border: none;
    background: #f8fafc;
    color: var(--text-muted);
    font-family: var(--font-family);
    font-size: 0.85rem;
    cursor: pointer;
    transition: var(--transition);
}

.toggle-btn.active {
    background: var(--primary-color);
    color: #fff;
}

.toggle-btn:hover:not(.active) {
    background: #edf2f7;
}

/* Chart Header */
.chart-section {
    margin-bottom: 2rem;
}

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

.chart-header h3 {
    margin: 0;
    font-size: 1.1rem;
    color: var(--text-dark);
}

.toggle-group {
    display: flex;
    background: #f1f5f9;
    padding: 0.2rem;
    border-radius: 8px;
    gap: 0.1rem;
}

.chart-toggle .toggle-btn {
    padding: 0.3rem 0.8rem;
    font-size: 0.75rem;
    border-radius: 6px;
    border: none;
    background: transparent;
}

.chart-toggle .toggle-btn.active {
    background: #fff;
    color: var(--primary-color);
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

.chart-toggle .toggle-btn:hover:not(.active) {
    background: rgba(0, 0, 0, 0.05);
}

/* Highlight Group */
.highlight-group {
    background: rgba(124, 185, 168, 0.08);
    border: 1px dashed var(--primary-color);
    padding: 0.75rem;
    border-radius: 8px;
    margin-top: 0.5rem;
}

/* Intervention Form */
.intervention-form {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.intervention-form .input-group {
    margin-bottom: 0.5rem;
}

/* Add Button */
.add-btn {
    background: var(--primary-color);
    color: #fff;
    border: none;
    border-radius: 8px;
    padding: 0.6rem 1rem;
    font-size: 0.85rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    white-space: nowrap;
    margin-top: 1.4rem;
}

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

/* Intervention List */
.intervention-list {
    margin-top: 0.75rem;
    max-height: 200px;
    overflow-y: auto;
}

.intervention-item {
    background: #f8fafc;
    border: 1px solid var(--card-border);
    padding: 0.5rem 0.75rem;
    margin-bottom: 0.4rem;
    border-radius: 6px;
    font-size: 0.8rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.remove-btn {
    color: var(--negative-color);
    cursor: pointer;
    padding: 0 0.25rem;
    font-size: 1rem;
}

/* Results Area */
.results-area {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

/* Summary Cards - Single Row Strip */
.summary-cards {
    display: flex;
    flex-wrap: wrap;
    gap: 2rem;
    align-items: center;
    background: var(--surface);
    border: 1px solid var(--card-border);
    border-radius: 12px;
    padding: 1rem 1.5rem;
    box-shadow: var(--card-shadow);
}

.card {
    background: transparent;
    border: none;
    border-radius: 0;
    padding: 0;
    text-align: left;
    box-shadow: none;
    display: flex;
    flex-direction: column;
    justify-content: center;
    min-height: auto;
    border-right: 1px solid #edf2f7;
    padding-right: 2rem;
}

.card:last-child {
    border-right: none;
    padding-right: 0;
}

.result-card {
    background: transparent;
    border-color: transparent;
}

.card h2 {
    color: var(--text-muted);
    font-size: 0.65rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 0.1rem;
}

.big-stat {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-main);
}

.big-stat.primary {
    color: var(--primary-color);
    font-size: 1.4rem;
}

.big-stat.positive {
    color: var(--positive-color);
}

.stat-label {
    font-size: 0.7rem;
    color: var(--text-muted);
    margin-top: 0.1rem;
}

/* Chart */
.chart-container {
    background: var(--surface);
    border: 1px solid var(--card-border);
    border-radius: 12px;
    padding: 1rem;
    height: 480px;
    box-shadow: var(--card-shadow);
}

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

.ledger-container h3 {
    margin: 0;
    color: var(--text-main);
    font-size: 1rem;
}

.table-wrapper {
    background: var(--surface);
    border: 1px solid var(--card-border);
    border-radius: 12px;
    max-height: 350px;
    overflow-y: auto;
    box-shadow: var(--card-shadow);
}

table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.8rem;
}

th {
    background: #f1f5f9;
    padding: 0.75rem 0.5rem;
    text-align: left;
    position: sticky;
    top: 0;
    color: var(--text-muted);
    font-weight: 600;
    font-size: 0.75rem;
    text-transform: uppercase;
}

td {
    padding: 0.6rem 0.5rem;
    border-bottom: 1px solid var(--card-border);
    color: var(--text-main);
}

tr:hover {
    background: #f8fafc;
}

tr.highlight {
    background: rgba(124, 185, 168, 0.12);
}

/* Fixed Rate Row Highlight */
tr.fixed-rate-row {
    background-color: rgba(66, 153, 225, 0.08);
    /* Light blue tint */
    border-left: 3px solid #4299e1;
}

tr.fixed-rate-row:hover {
    background-color: rgba(66, 153, 225, 0.15);
}

/* Split Rate Row Highlight */
tr.split-rate-row {
    background-color: rgba(72, 187, 120, 0.08);
    /* Light green tint */
    border-left: 3px solid #48bb78;
}

tr.split-rate-row:hover {
    background-color: rgba(72, 187, 120, 0.15);
}

/* Responsive */
/* Responsive */
@media (max-width: 1000px) {
    .layout-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    .summary-cards {
        grid-template-columns: repeat(3, 1fr);
    }

    .card {
        border-right: none;
        padding-right: 0;
        border-bottom: 1px solid #edf2f7;
        padding-bottom: 1rem;
        margin-bottom: 1rem;
    }
}

@media (max-width: 768px) {
    .header {
        padding: 1rem;
        border-radius: 0;
    }

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

    .header-actions {
        width: 100%;
        justify-content: flex-end;
    }

    .brand h1 {
        font-size: 1.5rem;
    }

    .summary-cards {
        grid-template-columns: repeat(2, 1fr);
        gap: 1rem;
    }

    .input-row.two-col {
        flex-direction: column;
    }

    .chart-container {
        height: 350px;
        padding: 0.5rem;
    }

    .ledger-container {
        overflow-x: auto;
    }

    table {
        min-width: 600px;
        /* Ensure table remains scrollable */
    }
}

@media (max-width: 480px) {
    body {
        padding: 0;
    }

    .calculator-container {
        padding: 0.5rem;
    }

    .summary-cards {
        grid-template-columns: 1fr;
    }

    .card {
        border-bottom: 1px solid #edf2f7;
        padding-bottom: 0.8rem;
        margin-bottom: 0.8rem;
        flex-direction: row;
        justify-content: space-between;
        align-items: center;
        border-right: none;
        padding-right: 0;
    }

    .card:last-child {
        border-bottom: none;
        margin-bottom: 0;
        padding-bottom: 0;
    }

    .card h2 {
        margin-bottom: 0;
    }

    .big-stat {
        font-size: 1rem;
    }

    .chart-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
    }

    .toggle-group {
        width: 100%;
    }

    .toggle-btn {
        padding: 0.4rem;
        font-size: 0.8rem;
    }
}

/* Info Area (FAQ & Support) */
.info-area {
    margin-top: 3rem;
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
    border-top: 1px solid var(--card-border);
    padding-top: 2rem;
}

/* FAQ Accordion */
.faq-section {
    background: var(--surface);
    border: 1px solid var(--card-border);
    border-radius: 12px;
    box-shadow: var(--card-shadow);
    overflow: hidden;
}

.faq-header {
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 1.5rem;
    background: none;
    border: none;
    cursor: pointer;
    transition: background 0.2s;
}

.faq-header:hover {
    background: #f8fafc;
}

.faq-header h3 {
    font-size: 1rem;
    color: var(--text-main);
    margin: 0;
}

.faq-header .arrow {
    color: var(--text-muted);
    font-size: 0.8rem;
    transition: transform 0.3s;
}

.faq-header.active .arrow {
    transform: rotate(180deg);
}

.faq-content {
    padding: 0 1.5rem 1.5rem 1.5rem;
    color: var(--text-main);
    border-top: 1px solid #f1f5f9;
    background: #fff;
    animation: slideDown 0.2s ease-out;
}

.faq-item {
    margin-bottom: 1rem;
}

.faq-item:last-child {
    margin-bottom: 0;
}

.faq-item h4 {
    font-size: 0.9rem;
    color: var(--primary-color);
    margin-bottom: 0.3rem;
}

.faq-item p {
    font-size: 0.85rem;
    color: #4a5568;
    line-height: 1.5;
}

/* Disclaimer Section */
.disclaimer-section {
    background: #fffaf0;
    border: 1px solid #fbd38d;
    border-radius: 12px;
    padding: 1.5rem;
    color: #744210;
    text-align: left;
}

.disclaimer-section h3 {
    font-size: 1rem;
    margin-bottom: 0.5rem;
    color: #975a16;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.disclaimer-section p {
    font-size: 0.85rem;
    line-height: 1.5;
    margin: 0;
}