:root {
    --primary: #13a4ec;
    --primary-dark: #0e86c2;
    --primary-light: #e7f6fd;
    --background-light: #f6f7f8;
    --background-dark: #101c22;
    --surface-light: #ffffff;
    --surface-dark: #1a2a33;
    --text-light: #0f172a;
    --text-dark: #f8fafc;
    --text-muted-light: #64748b;
    --text-muted-dark: #94a3b8;
    --border-light: #e2e8f0;
    --border-dark: #2d3e4a;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

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

body {
    background-color: var(--background-light);
    color: var(--text-light);
    transition: background-color 0.3s, color 0.3s;
    min-height: 100dvh;
}

body.dark {
    background-color: var(--background-dark);
    color: var(--text-dark);
}

.app-container {
    max-width: 430px;
    margin: 0 auto;
    background-color: var(--surface-light);
    min-height: 100dvh;
    display: flex;
    flex-direction: column;
    position: relative;
    box-shadow: var(--shadow-lg);
}

.dark .app-container {
    background-color: var(--surface-dark);
}

/* Common UI Components */
.btn-primary {
    background-color: var(--primary);
    color: white;
    border: none;
    padding: 1rem 1.5rem;
    border-radius: var(--radius-lg);
    font-weight: 700;
    cursor: pointer;
    transition: transform 0.2s, background-color 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.btn-primary:active {
    transform: scale(0.98);
}

.card {
    background-color: var(--surface-light);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-xl);
    padding: 1.25rem;
    box-shadow: var(--shadow-sm);
}

.dark .card {
    background-color: rgba(255, 255, 255, 0.03);
    border-color: var(--border-dark);
}

/* Navigations */
.bottom-nav {
    position: sticky;
    bottom: 0;
    width: 100%;
    background-color: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    border-top: 1px solid var(--border-light);
    display: flex;
    justify-content: space-around;
    padding: 0.75rem 1rem calc(0.75rem + env(safe-area-inset-bottom));
    z-index: 100;
}

.dark .bottom-nav {
    background-color: rgba(26, 42, 51, 0.9);
    border-color: var(--border-dark);
}

.nav-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.25rem;
    text-decoration: none;
    color: var(--text-muted-light);
    font-size: 0.7rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    transition: color 0.2s;
    background: none;
    border: none;
    cursor: pointer;
}

.nav-item.active {
    color: var(--primary);
}

.dark .nav-item {
    color: var(--text-muted-dark);
}

.dark .nav-item.active {
    color: var(--primary);
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }

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

@keyframes slideUp {
    from {
        transform: translateY(100%);
    }

    to {
        transform: translateY(0);
    }
}

.screen {
    animation: fadeIn 0.4s ease-out;
    padding: 1rem;
    flex: 1;
}

.tip-btn.active .tip-star {
    color: #D69E2E !important;
    filter: drop-shadow(0 0 5px rgba(214, 158, 46, 0.4));
}

.tip-btn.active span:last-child {
    color: #D69E2E !important;
    font-weight: 900;
}

.city-delete {
    padding: 0.5rem;
    color: #ef4444;
    cursor: pointer;
    opacity: 0.6;
    transition: opacity 0.2s, transform 0.2s;
}

.city-delete:hover {
    opacity: 1;
    transform: scale(1.1);
}

#solar-map {
    border-radius: 1rem;
    z-index: 1;
}

.flex-wrap {
    flex-wrap: wrap;
}

.gap-4 {
    gap: 1rem;
}

.gap-3 {
    gap: 0.75rem;
}

/* Hide Spinners */
input::-webkit-outer-spin-button,
input::-webkit-inner-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

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

.hide {
    display: none !important;
}

.leaflet-container {
    background: #aad3df !important;
}

/* Premium Skin Previews */
.skin-preview-cyber {
    background: linear-gradient(135deg, #00f2fe 0%, #4facfe 100%);
    box-shadow: 0 0 15px rgba(79, 172, 254, 0.4);
}

.skin-preview-midnight {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    box-shadow: 0 0 15px rgba(118, 75, 162, 0.4);
}

.skin-preview-default {
    background: #13a4ec;
}

.skin-card.locked {
    filter: grayscale(1) opacity(0.5);
    cursor: not-allowed;
}

.skin-card.selected {
    border-color: var(--primary) !important;
    transform: translateY(-4px);
}

/* Split Slider UX */
#split-slider {
    background: linear-gradient(to right, var(--slider-color, var(--primary)) 0%, var(--slider-color, var(--primary)) var(--progress, 0%), rgba(226, 232, 240, 1) var(--progress, 0%));
    margin-bottom: 24px;
    transition: background 0.1s ease;
    width: 100%;
    height: 6px;
    border-radius: 9999px;
    appearance: none;
    outline: none;
}

#split-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 24px;
    height: 24px;
    background: #fff;
    border: 3px solid var(--slider-color, var(--primary));
    border-radius: 50%;
    cursor: pointer;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
    transition: transform 0.1s ease, border-color 0.2s ease;
    margin-top: 0;
    /* Center in track */
}

#split-slider::-webkit-slider-thumb:active {
    transform: scale(1.2);
}

.slider-ticks {
    position: relative;
    height: 30px;
    margin-top: -8px;
    padding: 0 12px;
    /* Precision offset for 24px thumb */
    width: 100%;
}

.slider-tick {
    position: absolute;
    font-size: 10px;
    font-weight: 800;
    color: #94a3b8;
    transform: translateX(-50%);
    cursor: pointer;
    text-align: center;
    padding: 10px 0;
    width: 30px;
}

.slider-tick::before {
    content: '';
    position: absolute;
    top: 4px;
    left: 50%;
    transform: translateX(-50%);
    width: 2px;
    height: 4px;
    background: #cbd5e1;
    border-radius: 1px;
}

.slider-tick.active {
    color: var(--primary);
}

.slider-tick.active::before {
    background: var(--primary);
}

/* Pro Section Styling */
.pro-card {
    background: linear-gradient(135deg, rgba(16, 185, 129, 0.05) 0%, rgba(19, 164, 236, 0.05) 100%);
    border: 1px dashed rgba(19, 164, 236, 0.3);
    border-radius: 1.5rem;
    padding: 1.25rem;
}

.premium-tag {
    background: linear-gradient(90deg, #fbbf24, #f59e0b);
    color: white;
    padding: 2px 8px;
    border-radius: 6px;
    font-size: 9px;
    font-weight: 900;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    display: inline-flex;
    align-items: center;
    gap: 3px;
    box-shadow: 0 2px 4px rgba(245, 158, 11, 0.2);
}

/* --- Final Integration Fixes --- */
.dark #bill-amount {
    color: #ffffff !important;
}

.dark input::placeholder {
    color: rgba(255, 255, 255, 0.3) !important;
}

header button:active {
    transform: scale(0.9);
}

.locked-slot {
    border-style: dashed !important;
    background: rgba(148, 163, 184, 0.05);
    filter: grayscale(0.5);
}

.dark .locked-slot {
    background: rgba(255, 255, 255, 0.02);
}

.unlock-cities-btn {
    width: 100%;
    background: linear-gradient(135deg, var(--primary) 0%, #4facfe 100%);
    color: white;
    border: none;
    border-radius: var(--radius-xl);
    font-weight: 800;
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    cursor: pointer;
    box-shadow: 0 4px 15px rgba(19, 164, 236, 0.3);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.unlock-cities-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(19, 164, 236, 0.4);
}

.benefit-card {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 1.25rem;
    padding: 1.25rem;
    display: flex;
    gap: 1rem;
    align-items: flex-start;
    transition: transform 0.2s;
}

.benefit-card:hover {
    transform: scale(1.02);
}

.benefit-icon-wrapper {
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

/* OCR Animation */
@keyframes scan-pulse {
    0% {
        transform: scale(1);
        opacity: 1;
    }

    50% {
        transform: scale(1.05);
        opacity: 0.8;
    }

    100% {
        transform: scale(1);
        opacity: 1;
    }
}

.scanning-active {
    animation: scan-pulse 1s infinite ease-in-out;
    background: var(--primary) !important;
    color: white !important;
}

/* Bottom Sheet */
.bottom-sheet-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 1000;
    display: flex;
    align-items: flex-end;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s, visibility 0.3s;
}

.bottom-sheet-overlay.active {
    opacity: 1;
    visibility: visible;
}

.bottom-sheet {
    width: 100%;
    max-width: 430px;
    margin: 0 auto;
    background: var(--surface-light);
    border-radius: var(--radius-xl) var(--radius-xl) 0 0;
    padding: 1.5rem;
    transform: translateY(100%);
    transition: transform 0.3s ease-out;
}

.dark .bottom-sheet {
    background: var(--surface-dark);
}

.bottom-sheet-overlay.active .bottom-sheet {
    transform: translateY(0);
}

.modal-option {
    width: 100%;
    padding: 1rem;
    text-align: left;
    background: none;
    border: none;
    border-bottom: 1px solid var(--border-light);
    font-weight: 600;
    color: var(--text-light);
    cursor: pointer;
}

.dark .modal-option {
    border-color: var(--border-dark);
    color: var(--text-dark);
}

.modal-option:last-child {
    border-bottom: none;
}

/* Solar Map placeholder */
.solar-map-card {
    background: linear-gradient(to bottom, #101c22, #1a2a33);
    height: 120px;
    border-radius: var(--radius-xl);
    position: relative;
    overflow: hidden;
}

.solar-map-overlay {
    position: absolute;
    inset: 0;
    background: url('https://lh3.googleusercontent.com/aida-public/AB6AXuBk9L30tJGCFjU61sG5MnYWcG_6yHHNLhswIWqsqyZCgkeYauQl1P7_YyXzvef6rvmGAodt1TEOJPwUVbMR9wAyJwdciTAOuAXnRIHsoFGi9YIb2XDwdqwkAcmKwtQ93icQqR9ESpjE4LknuW8ESa4hClUxaxSF2vg612KNgXYvdOl9kGqeSoCSxW85scsIbsW2ba2UCAH1REFZjM1Ni8ezGOpdQzNV8BrekJ9nOXb-FabRIxEFAJicaLOhGQl9fuPxXqruV97g1J3U');
    background-size: cover;
    opacity: 0.3;
    filter: grayscale(100%);
}

/* Search Dropdown */
.search-dropdown {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--surface-light);
    border: 1px solid var(--border-light);
    border-radius: 0 0 var(--radius-lg) var(--radius-lg);
    box-shadow: var(--shadow-lg);
    z-index: 200;
    max-height: 200px;
    overflow-y: auto;
    margin-top: 4px;
}

.dark .search-dropdown {
    background: var(--surface-dark);
    border-color: var(--border-dark);
}

.search-item {
    width: 100%;
    padding: 0.75rem 1rem;
    text-align: left;
    background: none;
    border: none;
    border-bottom: 1px solid var(--border-light);
    color: var(--text-light);
    font-size: 0.85rem;
    cursor: pointer;
    transition: background 0.2s;
}

.dark .search-item {
    border-color: var(--border-dark);
    color: var(--text-dark);
}

.search-item:hover {
    background: var(--primary-light);
    color: var(--primary);
}

.dark .search-item:hover {
    background: rgba(19, 164, 236, 0.1);
}