/* Base Styles & Variables */
:root {
    --bg-color: #121212;
    --card-bg: #1e1e1e;
    --text-primary: #e0e0e0;
    --text-secondary: #a0a0a0;
    --accent-color: #3b82f6;
    --accent-hover: #2563eb;
    --success-color: #22c55e;
    --warning-color: #eab308;
    --danger-color: #ef4444;
    --input-bg: #2d2d2d;
    --border-color: #404040;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    padding: 1rem;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.container {
    width: 100%;
    max-width: 900px;
    /* Slightly wider for the extra column */
    padding-bottom: 120px;
}

/* Header */
header {
    margin-bottom: 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

header .title-group {
    display: flex;
    align-items: center;
    gap: 1rem;
}

h1 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
}

.icon-btn {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 50%;
    transition: background 0.2s;
}

.icon-btn:hover {
    background: var(--input-bg);
}

.settings-group {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background: var(--card-bg);
    padding: 0.5rem 1rem;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    flex-wrap: wrap;
}

.settings-group label {
    font-size: 0.875rem;
    color: var(--text-secondary);
    white-space: nowrap;
}

.vat-input {
    width: 50px;
    background: transparent;
    border: none;
    color: var(--accent-color);
    font-weight: 700;
    font-size: 1rem;
    text-align: right;
    border-bottom: 1px solid transparent;
}

.vat-input:focus {
    outline: none;
    border-bottom: 1px solid var(--accent-color);
}

/* Calculator Card (Row) */
.calc-row {
    background-color: var(--card-bg);
    border-radius: 12px;
    padding: 1rem;
    margin-bottom: 1rem;
    border: 1px solid var(--border-color);
    position: relative;
    transition: transform 0.2s, box-shadow 0.2s;
}

.calc-row:hover {
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

.row-header {
    display: flex;
    justify-content: space-between;
    margin-bottom: 0.75rem;
    align-items: center;
    color: var(--text-secondary);
    font-size: 0.85rem;
}

.row-actions {
    display: flex;
    gap: 0.5rem;
}

.action-btn {
    background: transparent;
    border: none;
    cursor: pointer;
    font-size: 1rem;
    padding: 2px 6px;
    border-radius: 4px;
    transition: background 0.2s;
}

.remove-btn {
    color: var(--danger-color);
    font-size: 1.2rem;
}

.clear-btn {
    color: var(--text-secondary);
    font-size: 0.9rem;
    border: 1px solid var(--border-color);
}

.clear-btn:hover {
    background: var(--input-bg);
    color: var(--text-primary);
}

/* Input Grid */
.input-grid {
    display: grid;
    /* Default 4 columns: [Cost] [Margin] [SellEx] [SellInc] */
    grid-template-columns: 1fr 1fr 1fr 1fr;
    gap: 0.75rem;
    margin-bottom: 1rem;
    transition: grid-template-columns 0.3s ease;
}

/* 5-Column Mode when RRP is visible */
.input-grid.has-rrp {
    /* [RRP] [Cost] [Margin] [SellEx] [SellInc] */
    grid-template-columns: 1fr 1fr 1fr 1fr 1fr;
}

.input-group {
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
}

/* RRP Group Toggling */
.rrp-group {
    display: flex;
    /* Normal state */
}

.rrp-group.hidden {
    display: none !important;
}

.input-group label {
    font-size: 0.75rem;
    color: var(--text-secondary);
    font-weight: 500;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.rrp-label {
    color: var(--warning-color) !important;
}

input[type="number"] {
    background-color: var(--input-bg);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 0.6rem;
    border-radius: 6px;
    font-size: 1rem;
    width: 100%;
    transition: border-color 0.2s;
}

input[type="number"]:focus {
    outline: none;
    border-color: var(--accent-color);
}

/* Readonly fields styling (like Calculated Cost) */
input[readonly] {
    opacity: 0.7;
    border-style: dashed;
    cursor: not-allowed;
}

/* Margin Input Styling */
.margin-input {
    font-weight: bold;
}

.margin-high {
    color: var(--success-color);
    border-color: var(--success-color) !important;
}

.margin-med {
    color: #facc15;
    border-color: #facc15 !important;
}

.margin-low {
    color: var(--danger-color);
    border-color: var(--danger-color) !important;
}

/* Results Section inside Row */
.results-inline {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 0.5rem;
    background: rgba(0, 0, 0, 0.2);
    padding: 0.75rem;
    border-radius: 8px;
}

.result-box {
    text-align: center;
}

.result-label {
    font-size: 0.7rem;
    color: var(--text-secondary);
    display: block;
    margin-bottom: 0.25rem;
}

.result-value {
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--text-primary);
}

.profit {
    color: var(--success-color);
}

.profit-item {
    transition: background-color 0.3s, color 0.3s;
    border-radius: 4px;
    padding: 2px 4px;
}

.profit-item.loss .profit {
    color: var(--danger-color);
}

.profit-item.loss {
    background-color: rgba(239, 68, 68, 0.1);
}

/* Floating Action Button */
.fab-container {
    position: fixed;
    bottom: 100px;
    right: 1.5rem;
    z-index: 50;
}

.fab {
    width: 56px;
    height: 56px;
    border-radius: 50%;
    background-color: var(--accent-color);
    color: white;
    border: none;
    font-size: 2rem;
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.5);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform 0.2s;
}

.fab:hover {
    transform: scale(1.05);
}

/* Grand Total Footer */
.grand-total-bar {
    position: fixed;
    bottom: 0;
    left: 0;
    width: 100%;
    background: var(--card-bg);
    border-top: 1px solid var(--border-color);
    padding: 1rem;
    display: flex;
    justify-content: space-around;
    align-items: center;
    box-shadow: 0 -4px 20px rgba(0, 0, 0, 0.4);
    z-index: 60;
    flex-wrap: wrap;
    gap: 1rem;
}

.total-group {
    text-align: center;
}

.total-label {
    font-size: 0.75rem;
    color: var(--text-secondary);
    display: block;
}

.total-value {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
}

#total-profit {
    color: var(--success-color);
}

/* Modal Styling */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
}

.modal.hidden {
    display: none;
}

.modal-content {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 12px;
    width: 90%;
    max-width: 400px;
    border: 1px solid var(--border-color);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.close-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 1.5rem;
    cursor: pointer;
}

.primary-btn {
    width: 100%;
    padding: 0.8rem;
    background: var(--accent-color);
    color: #000;
    border: none;
    border-radius: 6px;
    font-weight: 600;
    cursor: pointer;
    margin-top: 1rem;
}

/* Legend Styling */
.legend {
    display: flex;
    gap: 1rem;
    margin-top: 1rem;
    padding: 1rem;
    background: var(--bg-color);
    border-radius: 6px;
}

.legend-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.9rem;
}

.dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
}

.dot.green {
    background: var(--success-color);
}

.dot.yellow {
    background: var(--warning-color);
}

.dot.red {
    background: var(--danger-color);
}

/* --- Mobile / Responsive --- */
@media (max-width: 768px) {
    header {
        flex-direction: column;
        align-items: stretch;
        gap: 1rem;
    }

    header .title-group {
        justify-content: space-between;
    }

    .settings-group {
        justify-content: space-between;
    }

    .input-grid {
        /* On tablet/mobile, default to 2 columns */
        grid-template-columns: 1fr 1fr;
    }

    /* When RRP is visible, how do we handle 5 items on mobile? 
       2 cols is still best, it will just wrap to 3 rows.
       RRP | Cost
       Margin | SellEx
       SellInc | [Empty]
    */
    .input-grid.has-rrp {
        grid-template-columns: 1fr 1fr;
    }

    .grand-total-bar {
        padding: 0.75rem;
        justify-content: space-between;
    }

    .grand-total-bar button {
        width: 100%;
        margin-bottom: 0.5rem;
    }

    .total-group {
        flex: 1;
    }
}