:root {
    /* Color Palette - Neon Dark */
    --bg-app: #0f1115;
    --bg-panel: #161b22;
    --bg-card: #1c2128;
    --bg-input: #0d1117;

    --text-primary: #f0f6fc;
    --text-secondary: #8b949e;
    --text-muted: #586069;

    --accent-primary: #58a6ff;
    /* Blue Core */
    --accent-glow: rgba(88, 166, 255, 0.4);

    --neon-green: #3fb950;
    --neon-purple: #bc8cff;
    --neon-pink: #ff7b72;

    --border-subtle: #30363d;
    --border-active: #58a6ff;

    --font-main: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;

    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;

    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 18px;

    --shadow-card: 0 4px 12px rgba(0, 0, 0, 0.3);
    --shadow-glow: 0 0 15px var(--accent-glow);

    --chart-line-growth: var(--neon-green);
    --chart-line-drawdown: var(--neon-purple);
}

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

body {
    background-color: var(--bg-app);
    color: var(--text-primary);
    font-family: var(--font-main);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
}

/* Layout */
.app-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--spacing-md);
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
}

@media (min-width: 900px) {
    .app-container {
        grid-template-columns: 380px 1fr;
        /* Sidebar Inputs | Main Output */
        padding: var(--spacing-xl);
        height: 100vh;
        overflow: hidden;
    }

    .input-section {
        overflow-y: auto;
        padding-right: var(--spacing-sm);
        /* Scrollbar styling */
        scrollbar-width: thin;
        scrollbar-color: var(--border-subtle) transparent;
    }

    .output-section {
        display: flex;
        flex-direction: column;
        gap: var(--spacing-lg);
        height: 100%;
        overflow-y: auto;
    }
}

/* Typography */
h1 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
    letter-spacing: -0.5px;
}

h2 {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
    text-transform: uppercase;
    letter-spacing: 1px;
    font-size: 0.8rem;
}

h3 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
}

.subtitle {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
}

/* Cards */
.card {
    background: var(--bg-card);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    border: 1px solid var(--border-subtle);
    box-shadow: var(--shadow-card);
    margin-bottom: var(--spacing-md);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.card:hover {
    border-color: var(--text-secondary);
}

/* Inputs */
.input-group {
    margin-bottom: var(--spacing-lg);
}

.input-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-sm);
}

.label-main {
    font-weight: 500;
    color: var(--text-primary);
    font-size: 0.95rem;
}

.input-row {
    display: flex;
    gap: var(--spacing-md);
    align-items: center;
}

.currency-input-wrapper {
    position: relative;
    flex: 1;
}

.currency-symbol {
    position: absolute;
    left: 12px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-secondary);
    pointer-events: none;
}

input[type="number"],
input[type="text"] {
    width: 100%;
    background: var(--bg-input);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-sm);
    padding: 10px 12px 10px 24px;
    color: var(--text-primary);
    font-family: var(--font-main);
    font-size: 1rem;
    transition: all 0.2s;
}

input[type="number"]:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(88, 166, 255, 0.1);
}

/* Range Sliders */
.range-wrapper {
    margin-top: var(--spacing-sm);
}

input[type="range"] {
    -webkit-appearance: none;
    width: 100%;
    height: 6px;
    background: var(--bg-input);
    border-radius: 3px;
    outline: none;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--accent-primary);
    cursor: pointer;
    box-shadow: 0 0 10px rgba(88, 166, 255, 0.5);
    transition: transform 0.1s;
    margin-top: -6px;
    /* center on track */
}

input[type="range"]::-webkit-slider-runnable-track {
    height: 6px;
    background: var(--border-subtle);
    border-radius: 3px;
    /* We will use JS to update the background gradient for progress */
}

input[type="range"]:active::-webkit-slider-thumb {
    transform: scale(1.2);
}

/* Toggles & Chips */
.toggle-group {
    display: flex;
    background: var(--bg-input);
    padding: 4px;
    border-radius: var(--radius-sm);
    gap: 4px;
}

.toggle-option {
    flex: 1;
    text-align: center;
    padding: 6px 12px;
    font-size: 0.85rem;
    color: var(--text-secondary);
    cursor: pointer;
    border-radius: 4px;
    transition: all 0.2s;
    user-select: none;
}

.toggle-option.active {
    background: var(--bg-panel);
    color: var(--text-primary);
    font-weight: 500;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.2);
}

.chip {
    padding: 4px 10px;
    background: var(--bg-input);
    border: 1px solid var(--border-subtle);
    border-radius: 20px;
    font-size: 0.75rem;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.2s;
}

.chip:hover {
    border-color: var(--accent-primary);
    color: var(--accent-primary);
}

.chip.active {
    background: rgba(88, 166, 255, 0.1);
    border-color: var(--accent-primary);
    color: var(--accent-primary);
}

.presets-row {
    display: flex;
    gap: 8px;
    margin-top: 8px;
    flex-wrap: wrap;
}

/* Collapsible Advanced */
.advanced-toggle {
    width: 100%;
    text-align: left;
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 0.9rem;
    padding: var(--spacing-md) 0;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 8px;
}

.advanced-toggle:hover {
    color: var(--text-primary);
}

.chevron {
    transition: transform 0.3s;
}

.advanced-section {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease-out;
}

.advanced-section.open {
    max-height: 2000px;
    /* arbitrary large number */
    transition: max-height 0.4s ease-in;
}

/* Output Panel */
.output-dashboard {
    background: linear-gradient(145deg, var(--bg-card), var(--bg-panel));
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    border: 1px solid var(--border-subtle);
    position: relative;
    overflow: hidden;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
}

.output-dashboard::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--neon-green), var(--neon-purple));
}

.big-metric {
    margin-bottom: var(--spacing-lg);
}

.metric-label {
    font-size: 0.9rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 4px;
}

.metric-value {
    font-size: 3rem;
    font-weight: 800;
    color: var(--text-primary);
    /* Gradient text */
    background: linear-gradient(90deg, #fff, var(--text-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    font-variant-numeric: tabular-nums;
}

.metric-sub {
    font-size: 1.1rem;
    color: var(--neon-green);
    font-weight: 600;
    margin-top: -5px;
}

.secondary-metrics {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: var(--spacing-md);
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--border-subtle);
}

.mini-metric .label {
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.mini-metric .value {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--text-primary);
    font-variant-numeric: tabular-nums;
}

/* Chart Container */
.chart-container {
    background: var(--bg-card);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    border: 1px solid var(--border-subtle);
    flex-grow: 1;
    min-height: 300px;
    position: relative;
}

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

/* Sticky Mobile Summary */
.mobile-summary {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: rgba(22, 27, 34, 0.95);
    backdrop-filter: blur(10px);
    padding: var(--spacing-md);
    border-top: 1px solid var(--border-subtle);
    display: flex;
    justify-content: space-between;
    align-items: center;
    z-index: 100;
    transform: translateY(100%);
    transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

.mobile-summary.visible {
    transform: translateY(0);
}

@media (min-width: 900px) {
    .mobile-summary {
        display: none;
    }
}

/* Validation */
.validation-msg {
    color: var(--neon-pink);
    font-size: 0.8rem;
    margin-top: 4px;
    display: none;
    animation: fadeIn 0.3s;
}

.validation-msg.visible {
    display: block;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(-5px);
    }

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

/* Accessibility - Reduced Motion */
@media (prefers-reduced-motion: reduce) {
    * {
        transition: none !important;
        animation: none !important;
    }
}

/* Value Inputs (Interactive Numbers) */
.value-input {
    background: transparent;
    border: 1px solid transparent;
    border-radius: var(--radius-sm);
    color: var(--accent-primary);
    font-size: 1.1rem;
    font-weight: 700;
    width: 60px;
    text-align: right;
    padding: 2px 4px;
    transition: all 0.2s;
    cursor: text;
    -moz-appearance: textfield;
}

.value-input:hover {
    background: var(--bg-input);
    border-color: var(--border-subtle);
}

.value-input:focus {
    background: var(--bg-input);
    border-color: var(--accent-primary);
    outline: none;
    width: 70px;
    /* Slight expansion */
}

.value-input::-webkit-outer-spin-button,
.value-input::-webkit-inner-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

/* Tooltip Styles */
.tooltip {
    position: relative;
    display: inline-flex;
    align-items: center;
    margin-left: 4px;
}

.tooltip-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: rgba(88, 166, 255, 0.15);
    color: var(--accent-primary);
    font-size: 11px;
    font-weight: 600;
    cursor: help;
    transition: all 0.2s;
    user-select: none;
}

.tooltip-icon:hover {
    background: rgba(88, 166, 255, 0.25);
    transform: scale(1.1);
}

.tooltip-content {
    position: absolute;
    bottom: calc(100% + 8px);
    left: 50%;
    transform: translateX(-50%);
    background: var(--bg-panel);
    border: 1px solid var(--border-active);
    border-radius: var(--radius-sm);
    padding: 8px 12px;
    font-size: 0.8rem;
    line-height: 1.4;
    color: var(--text-primary);
    white-space: nowrap;
    max-width: 280px;
    white-space: normal;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.4);
    z-index: 1000;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.2s;
}

/* Special positioning for tooltips in toggle buttons to avoid clipping */
.toggle-option .tooltip-content {
    bottom: auto;
    top: calc(100% + 8px);
    left: auto;
    right: 0;
    transform: none;
}

.tooltip-content::after {
    content: '';
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%);
    border: 6px solid transparent;
    border-top-color: var(--border-active);
}

/* Adjust arrow for right-aligned tooltips that display below */
.toggle-option .tooltip-content::after {
    top: auto;
    bottom: 100%;
    left: auto;
    right: 12px;
    transform: none;
    border-top-color: transparent;
    border-bottom-color: var(--border-active);
}

.tooltip:hover .tooltip-content,
.tooltip-icon:focus+.tooltip-content {
    opacity: 1;
    pointer-events: auto;
}

/* Mobile: Show on tap */
@media (hover: none) {
    .tooltip-icon:active+.tooltip-content {
        opacity: 1;
        pointer-events: auto;
    }
}