:root {
    /* Base Variables (Default Dark / Cosmic) */
    --bg-color: #0b0f19;
    --bg-gradient: radial-gradient(circle at 15% 50%, rgba(76, 29, 149, 0.15), transparent 25%),
        radial-gradient(circle at 85% 30%, rgba(14, 165, 233, 0.15), transparent 25%);
    --card-bg: rgba(30, 41, 59, 0.6);
    --card-border: rgba(255, 255, 255, 0.08);

    --text-primary: #ffffff;
    --text-secondary: #94a3b8;

    --accent-primary: #8b5cf6;
    --accent-secondary: #0ea5e9;
    --accent-gradient: linear-gradient(135deg, #8b5cf6, #0ea5e9);

    --success-color: #10b981;
    --danger-color: #ef4444;

    --font-family: 'Outfit', sans-serif;
    --card-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --glow-shadow: 0 0 20px rgba(139, 92, 246, 0.15);

    --chart-grid: rgba(255, 255, 255, 0.05);
    --chart-text: #94a3b8;

    --modal-overlay: rgba(11, 15, 25, 0.85);
    --modal-bg: rgba(30, 41, 59, 0.8);
    --input-bg: rgba(11, 15, 25, 0.6);
}

/* Light Mode Variables */
[data-theme="light"] {
    --bg-color: #f8fafc;
    --bg-gradient: radial-gradient(circle at 15% 50%, rgba(139, 92, 246, 0.05), transparent 25%),
        radial-gradient(circle at 85% 30%, rgba(14, 165, 233, 0.05), transparent 25%);
    --card-bg: rgba(255, 255, 255, 0.9);
    --card-border: rgba(148, 163, 184, 0.2);

    --text-primary: #0f172a;
    --text-secondary: #64748b;

    --accent-primary: #7c3aed;
    /* Darker violet for better contrast */
    --accent-secondary: #0284c7;

    --card-shadow: 0 4px 6px -1px rgba(148, 163, 184, 0.1), 0 2px 4px -1px rgba(148, 163, 184, 0.06);
    --glow-shadow: 0 4px 12px rgba(124, 58, 237, 0.2);

    --chart-grid: rgba(0, 0, 0, 0.05);
    --chart-text: #64748b;

    --modal-overlay: rgba(255, 255, 255, 0.85);
    --modal-bg: rgba(255, 255, 255, 0.95);
    --input-bg: #f1f5f9;
}

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

body {
    background-color: var(--bg-color);
    background-image: var(--bg-gradient);
    background-attachment: fixed;
    color: var(--text-primary);
    font-family: var(--font-family);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    transition: background-color 0.3s, color 0.3s;
}

.app-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 2rem;
    width: 100%;
}

/* Header */
header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2.5rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid var(--card-border);
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.75rem;
    font-weight: 700;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    filter: drop-shadow(0 0 10px rgba(139, 92, 246, 0.3));
}

.logo i {
    font-size: 2rem;
    color: #8b5cf6;
    /* Fallback for icon if gradient doesn't apply well to FA */
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* Theme Toggle Button */
.theme-toggle {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-size: 1.25rem;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 50%;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.theme-toggle:hover {
    background: rgba(124, 58, 237, 0.1);
    color: var(--accent-primary);
}

.date-controls {
    display: flex;
    align-items: center;
    gap: 1rem;
    background: var(--card-bg);
    /* Use card-bg which adapts */
    padding: 0.5rem 1rem;
    border-radius: 16px;
    border: 1px solid var(--card-border);
    backdrop-filter: blur(12px);
    transition: background-color 0.3s, border-color 0.3s;
}

input[type="date"] {
    background: transparent;
    border: 1px solid transparent;
    color: var(--text-primary);
    font-family: var(--font-family);
    font-size: 0.95rem;
    padding: 0.4rem 0.6rem;
    border-radius: 8px;
    transition: all 0.3s ease;
}

input[type="date"]:hover,
input[type="date"]:focus {
    background: var(--input-bg);
    border-color: var(--card-border);
}

input[type="date"]::-webkit-calendar-picker-indicator {
    filter: invert(1);
    cursor: pointer;
    opacity: 0.7;
    transition: opacity 0.2s;
}

input[type="date"]::-webkit-calendar-picker-indicator:hover {
    opacity: 1;
}

/* Fix calendar icon color in light mode */
[data-theme="light"] input[type="date"]::-webkit-calendar-picker-indicator {
    filter: none;
    opacity: 0.6;
}

.separator {
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
}

.btn-primary {
    background: var(--accent-gradient);
    color: white;
    border: none;
    padding: 0.6rem 1.5rem;
    border-radius: 12px;
    font-family: var(--font-family);
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: var(--glow-shadow);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px -5px rgba(139, 92, 246, 0.4);
    filter: brightness(1.1);
}

.btn-primary:active {
    transform: translateY(0);
}

.btn-secondary {
    background: transparent;
    border: 1px solid var(--card-border);
    color: var(--text-secondary);
    padding: 0.6rem 1.2rem;
    border-radius: 12px;
    cursor: pointer;
    font-family: var(--font-family);
    transition: all 0.2s;
}

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

.hidden {
    display: none !important;
}

/* Cards & Layout */
.card {
    background: var(--card-bg);
    border-radius: 20px;
    padding: 1.75rem;
    border: 1px solid var(--card-border);
    box-shadow: var(--card-shadow);
    backdrop-filter: blur(16px);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 30px -10px rgba(0, 0, 0, 0.1);
    border-color: var(--text-secondary);
}

.card-header-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.25rem;
}

h3 {
    color: var(--text-secondary);
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: 0;
    /* Remove bottom margin as it's handled by header-row now if used */
    font-weight: 600;
}

/* View Switcher */
.view-switcher {
    display: flex;
    background: var(--input-bg);
    border-radius: 8px;
    padding: 2px;
    border: 1px solid var(--card-border);
}

.view-btn {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    padding: 0.3rem 0.8rem;
    font-size: 0.8rem;
    font-family: var(--font-family);
    cursor: pointer;
    border-radius: 6px;
    transition: all 0.2s;
}

.view-btn.active {
    background: var(--accent-gradient);
    color: white;
    font-weight: 600;
}

.view-btn:hover:not(.active) {
    color: var(--text-primary);
}

.summary-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.total-cost-card .value {
    font-size: 3rem;
    font-weight: 700;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    margin-bottom: 0.5rem;
    letter-spacing: -0.02em;
}

.trend-card .value {
    font-size: 1.75rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

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

#topRegionAmount {
    color: var(--accent-secondary);
    font-weight: 600;
    font-size: 1.1rem;
}

.charts-container {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 1.5rem;
}

@media (max-width: 1024px) {
    .charts-container {
        grid-template-columns: 1fr;
    }
}

.chart-wrapper {
    position: relative;
    height: 380px;
    width: 100%;
}

/* Table */
.table-container {
    overflow-x: auto;
}

table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
}

th,
td {
    padding: 1rem 0.5rem;
    text-align: left;
    border-bottom: 1px solid var(--card-border);
}

th {
    color: var(--text-secondary);
    font-weight: 600;
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

td {
    font-size: 0.95rem;
    color: var(--text-primary);
}

tbody tr {
    transition: background-color 0.2s;
}

tbody tr.main-row {
    cursor: pointer;
}

tbody tr.main-row:hover {
    background-color: var(--input-bg);
}

/* Expandable rows */
.nested-row {
    background-color: rgba(0, 0, 0, 0.1);
    display: none;
}

.nested-row.show {
    display: table-row;
}

.nested-table {
    width: 95%;
    margin: 0.5rem auto;
    background: transparent;
}

.nested-table td {
    padding: 0.5rem;
    font-size: 0.85rem;
    color: var(--text-secondary);
    border-bottom: 1px dashed var(--card-border);
}

.nested-table tr:last-child td {
    border-bottom: none;
}

.row-toggle-icon {
    display: inline-block;
    width: 16px;
    transition: transform 0.2s;
    margin-right: 0.5rem;
    color: var(--accent-secondary);
}

.main-row.expanded .row-toggle-icon {
    transform: rotate(90deg);
}

tr:last-child td {
    border-bottom: none;
}

.error-banner {
    background: rgba(239, 68, 68, 0.1);
    border: 1px solid var(--danger-color);
    color: var(--danger-color);
    padding: 0.75rem 1rem;
    border-radius: 12px;
    font-size: 0.85rem;
    margin-bottom: 1.5rem;
    text-align: center;
    animation: shake 0.5s cubic-bezier(.36, .07, .19, .97) both;
}

@keyframes shake {

    10%,
    90% {
        transform: translate3d(-1px, 0, 0);
    }

    20%,
    80% {
        transform: translate3d(2px, 0, 0);
    }

    30%,
    50%,
    70% {
        transform: translate3d(-4px, 0, 0);
    }

    40%,
    60% {
        transform: translate3d(4px, 0, 0);
    }
}

/* Modal */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--modal-overlay);
    /* Darker backdrop */
    backdrop-filter: blur(12px);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 2000;
}

.modal-content {
    background: var(--modal-bg);
    padding: 2.5rem;
    border-radius: 24px;
    border: 1px solid var(--card-border);
    width: 100%;
    max-width: 450px;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
    position: relative;
    overflow: hidden;
}

/* Little glow effect on modal top */
.modal-content::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--accent-gradient);
}

.modal-header {
    text-align: center;
    margin-bottom: 2rem;
}

.modal-header h2 {
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    font-size: 1.75rem;
    font-weight: 700;
}

.demo-note {
    margin-top: 1rem;
    font-size: 0.85rem !important;
    opacity: 0.6;
    font-style: italic;
    margin-bottom: 0.5rem;
}

.help-link {
    display: inline-block;
    color: var(--accent-secondary);
    text-decoration: none;
    font-size: 0.85rem;
    margin-top: 0.5rem;
    transition: all 0.2s;
}

.help-link:hover {
    color: var(--accent-primary);
    text-decoration: underline;
}

.help-link i {
    margin-right: 4px;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
    font-weight: 500;
}

.form-group input {
    width: 100%;
    background: var(--input-bg);
    border: 1px solid var(--card-border);
    padding: 0.85rem;
    border-radius: 12px;
    color: var(--text-primary);
    font-family: var(--font-family);
    outline: none;
    transition: all 0.2s;
}

.form-group input:focus {
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 2px rgba(139, 92, 246, 0.2);
}

.button-group {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
}

.button-group button {
    flex: 1;
}

/* Loader */
.loader-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(11, 15, 25, 0.9);
    backdrop-filter: blur(5px);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 3000;
    transition: opacity 0.3s;
}

.loader-overlay.hidden {
    opacity: 0;
    pointer-events: none;
}

.spinner {
    width: 50px;
    height: 50px;
    border: 4px solid rgba(255, 255, 255, 0.1);
    border-top-color: var(--accent-primary);
    border-radius: 50%;
    animation: spin 1s cubic-bezier(0.55, 0.085, 0.68, 0.53) infinite;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

/* Scrollbar */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-color);
}

::-webkit-scrollbar-thumb {
    background: #334155;
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: #475569;
}