/* CSS Custom Properties */
:root {
    --color-primary: #2563eb;
    --color-primary-dark: #1d4ed8;
    --color-positive: #16a34a;
    --color-negative: #dc2626;
    --color-bg: #f8fafc;
    --color-bg-card: #ffffff;
    --color-text: #1e293b;
    --color-text-muted: #64748b;
    --color-border: #e2e8f0;
    --color-input-bg: #ffffff;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
    --radius: 8px;
    --radius-lg: 12px;
    --transition: 0.2s ease;
}

[data-theme="dark"] {
    --color-bg: #0f172a;
    --color-bg-card: #1e293b;
    --color-text: #f1f5f9;
    --color-text-muted: #94a3b8;
    --color-border: #334155;
    --color-input-bg: #0f172a;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5);
}

/* Reset & Base */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background-color: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    transition: background-color var(--transition), color var(--transition);
}

/* Header */
.header {
    background-color: var(--color-bg-card);
    border-bottom: 1px solid var(--color-border);
    padding: 1rem 1.5rem;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-sm);
}

.header-content {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-text);
}

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

.theme-toggle {
    background: none;
    border: 2px solid var(--color-border);
    border-radius: var(--radius);
    padding: 0.5rem;
    cursor: pointer;
    font-size: 1.25rem;
    line-height: 1;
    color: var(--color-text);
    transition: border-color var(--transition), background-color var(--transition);
}

.theme-toggle:hover {
    border-color: var(--color-primary);
    background-color: var(--color-bg);
}

.icon-moon { display: none; }
[data-theme="dark"] .icon-sun { display: none; }
[data-theme="dark"] .icon-moon { display: inline; }

/* Hero Section */
.hero {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem 1.5rem 1rem;
    text-align: center;
}

.hero h2 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--color-text);
    margin-bottom: 0.5rem;
}

.hero p {
    font-size: 1.125rem;
    color: var(--color-text-muted);
    max-width: 600px;
    margin: 0 auto;
}

@media (max-width: 640px) {
    .hero {
        padding: 1.5rem 1rem 0.75rem;
    }

    .hero h2 {
        font-size: 1.5rem;
    }

    .hero p {
        font-size: 1rem;
    }
}

/* Quick Nav */
.quick-nav {
    background-color: var(--color-bg-card);
    border-bottom: 1px solid var(--color-border);
    padding: 1rem 1.5rem;
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 0.5rem;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
}

.quick-nav a {
    color: var(--color-text);
    text-decoration: none;
    padding: 0.625rem 1.25rem;
    border-radius: 50px;
    font-size: 0.875rem;
    font-weight: 500;
    white-space: nowrap;
    background-color: var(--color-bg);
    border: 1px solid var(--color-border);
    transition: all var(--transition);
    box-shadow: var(--shadow-sm);
}

.quick-nav a:hover {
    background-color: var(--color-primary);
    border-color: var(--color-primary);
    color: white;
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

/* Ad Containers */
.ad-container {
    display: none; /* Temporarily hidden */
    max-width: 1200px;
    margin: 1.5rem auto;
    padding: 0 1.5rem;
}

.ad-placeholder {
    background-color: var(--color-bg-card);
    border: 2px dashed var(--color-border);
    border-radius: var(--radius);
    padding: 2rem;
    text-align: center;
    color: var(--color-text-muted);
    font-size: 0.875rem;
}

.ad-leaderboard .ad-placeholder {
    min-height: 90px;
}

.ad-inline .ad-placeholder {
    min-height: 250px;
}

.ad-image {
    display: block;
    max-width: 100%;
    height: auto;
    margin: 0 auto;
    border-radius: var(--radius);
}

.ad-leaderboard {
    text-align: center;
}

.ad-inline {
    text-align: center;
}

/* Main Content */
.main-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

/* Calculator Cards */
.calculator-card {
    background-color: var(--color-bg-card);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    overflow: hidden;
    transition: box-shadow var(--transition);
}

.calculator-card:hover {
    box-shadow: var(--shadow-lg);
}

.card-header {
    padding: 1.5rem;
    border-bottom: 1px solid var(--color-border);
}

.card-header h2 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.card-description {
    color: var(--color-text-muted);
    font-size: 0.9375rem;
}

.calculator-body {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
    padding: 1.5rem;
}

@media (min-width: 768px) {
    .calculator-body {
        grid-template-columns: 1fr 1fr;
    }
}

/* Input Section */
.inputs-section {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.inputs-section-wide {
    grid-column: 1 / -1;
}

.input-section-title {
    font-size: 0.875rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-text-muted);
    margin-top: 0.5rem;
}

.input-group {
    display: flex;
    flex-direction: column;
    gap: 0.375rem;
}

.input-group label {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--color-text);
}

.input-wrapper {
    position: relative;
}

.input-wrapper.currency::before {
    content: '$';
    position: absolute;
    left: 0.75rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--color-text-muted);
    font-size: 0.875rem;
}

.input-wrapper.percent::after {
    content: '%';
    position: absolute;
    right: 0.75rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--color-text-muted);
    font-size: 0.875rem;
}

.input-wrapper.currency input {
    padding-left: 1.75rem;
}

.input-wrapper.percent input {
    padding-right: 1.75rem;
}

input[type="number"],
select {
    width: 100%;
    padding: 0.625rem 0.75rem;
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    font-size: 1rem;
    color: var(--color-text);
    background-color: var(--color-input-bg);
    transition: border-color var(--transition), box-shadow var(--transition);
}

input[type="number"]:focus,
select:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

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

input[type="number"] {
    -moz-appearance: textfield;
}

/* Formula Details */
.formula-details {
    margin-top: 0.5rem;
    font-size: 0.8125rem;
}

.formula-details summary {
    cursor: pointer;
    color: var(--color-primary);
    font-weight: 500;
}

.formula-details p {
    margin-top: 0.5rem;
    padding: 0.75rem;
    background-color: var(--color-bg);
    border-radius: var(--radius);
    font-family: 'SF Mono', Monaco, 'Courier New', monospace;
}

.formula-legend {
    font-family: inherit !important;
    font-size: 0.75rem;
    color: var(--color-text-muted);
}

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

.results-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: 1rem;
}

.results-grid-2col {
    grid-template-columns: repeat(2, 1fr);
}

.result-item {
    background-color: var(--color-bg);
    padding: 1rem;
    border-radius: var(--radius);
    text-align: center;
}

.result-item-large {
    grid-column: 1 / -1;
    padding: 1.5rem;
}

.result-label {
    display: block;
    font-size: 0.75rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-text-muted);
    margin-bottom: 0.25rem;
}

.result-value {
    display: block;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-text);
}

.result-item-large .result-value {
    font-size: 2rem;
}

.result-value.positive {
    color: var(--color-positive);
}

.result-value.negative {
    color: var(--color-negative);
}

.result-hint {
    display: block;
    font-size: 0.6875rem;
    color: var(--color-text-muted);
    margin-top: 0.25rem;
}

/* Tax breakdown table */
.tax-table {
    width: 100%;
    font-size: 0.8125rem;
    border-collapse: collapse;
}

.tax-table td {
    padding: 0.375rem 0;
    border-bottom: 1px solid var(--color-border);
}

.tax-table td:last-child {
    text-align: right;
    font-family: 'SF Mono', Monaco, 'Courier New', monospace;
}

.tax-table tr.tax-total td {
    border-bottom: none;
    border-top: 2px solid var(--color-border);
    padding-top: 0.5rem;
}

.tax-breakdown {
    margin-bottom: 1rem;
}

.input-hint {
    font-size: 0.75rem;
    color: var(--color-text-muted);
    margin-top: 0.25rem;
}

.input-row {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.input-flex {
    flex: 1;
}

.input-small {
    width: 80px;
    flex-shrink: 0;
}

.input-or {
    color: var(--color-text-muted);
    font-size: 0.875rem;
}

/* Tip calculator buttons */
.input-buttons {
    display: flex;
    gap: 0.5rem;
}

.tip-btn {
    flex: 1;
    padding: 0.5rem 0.75rem;
    border: 2px solid var(--color-border);
    border-radius: var(--radius);
    background: var(--color-input-bg);
    color: var(--color-text);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition);
}

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

.tip-btn.active {
    background: var(--color-primary);
    border-color: var(--color-primary);
    color: white;
}

.split-btn {
    width: 40px;
    height: 40px;
    border: 2px solid var(--color-border);
    border-radius: var(--radius);
    background: var(--color-input-bg);
    color: var(--color-text);
    font-size: 1.25rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition);
}

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

.input-row input[type="number"] {
    width: 60px;
    text-align: center;
}

/* Scenario buttons */
.scenario-buttons {
    display: flex;
    gap: 0.5rem;
}

.scenario-btn {
    flex: 1;
    padding: 0.625rem 0.5rem;
    border: 2px solid var(--color-border);
    border-radius: var(--radius);
    background: var(--color-input-bg);
    color: var(--color-text);
    cursor: pointer;
    transition: all var(--transition);
    text-align: center;
}

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

.scenario-btn.active {
    background: var(--color-primary);
    border-color: var(--color-primary);
    color: white;
}

.scenario-label {
    display: block;
    font-size: 0.8125rem;
    font-weight: 600;
}

.scenario-detail {
    display: block;
    font-size: 0.6875rem;
    opacity: 0.8;
    margin-top: 0.125rem;
}

/* Currency swap button */
.swap-btn {
    width: 44px;
    height: 44px;
    border: 2px solid var(--color-border);
    border-radius: 50%;
    background: var(--color-input-bg);
    color: var(--color-primary);
    font-size: 1.25rem;
    cursor: pointer;
    transition: all var(--transition);
}

.swap-btn:hover {
    background: var(--color-primary);
    border-color: var(--color-primary);
    color: white;
    transform: rotate(180deg);
}

/* Footer copyright */
.footer-copyright {
    margin-top: 0.5rem;
    font-size: 0.75rem;
    opacity: 0.7;
}

.positive-text {
    color: var(--color-positive);
}

.negative-text {
    color: var(--color-negative);
}

/* Charts */
.chart-container {
    min-height: 200px;
    position: relative;
}

.chart-container-dual {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
}

.chart-container canvas {
    max-width: 100%;
}

.chart-container-dual .chart-wrapper {
    width: 100%;
    max-width: 300px;
    margin: 0 auto;
}

/* Net Worth Columns */
.net-worth-columns {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
}

@media (min-width: 640px) {
    .net-worth-columns {
        grid-template-columns: 1fr 1fr;
    }
}

.nw-column {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

/* Footer */
.footer {
    text-align: center;
    padding: 2rem 1.5rem;
    color: var(--color-text-muted);
    font-size: 0.875rem;
    border-top: 1px solid var(--color-border);
    margin-top: 2rem;
}

.footer-links {
    margin-top: 0.5rem;
}

.footer-links a {
    color: var(--color-primary);
    text-decoration: none;
}

.footer-links a:hover {
    text-decoration: underline;
}

/* Responsive adjustments */
@media (max-width: 640px) {
    .header {
        padding: 0.75rem 1rem;
    }

    .logo {
        font-size: 1.25rem;
    }

    .quick-nav {
        padding: 0.5rem 1rem;
    }

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

    .card-header {
        padding: 1rem;
    }

    .card-header h2 {
        font-size: 1.25rem;
    }

    .calculator-body {
        padding: 1rem;
    }

    .result-value {
        font-size: 1.25rem;
    }

    .result-item-large .result-value {
        font-size: 1.5rem;
    }

    .chart-container-dual {
        grid-template-columns: 1fr;
    }

    .chart-container-dual .chart-wrapper {
        max-width: 250px;
    }
}