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

body {
    font-family: 'Comic Sans MS', 'Arial', sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    background: white;
    border-radius: 20px;
    padding: 30px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
}

header {
    text-align: center;
    margin-bottom: 30px;
    padding-bottom: 20px;
    border-bottom: 3px solid #667eea;
}

h1 {
    color: #667eea;
    font-size: 2.5em;
    margin-bottom: 10px;
}

.subtitle {
    color: #666;
    font-size: 1.2em;
}

/* Tabs Navigation */
.tabs {
    display: flex;
    gap: 10px;
    margin-bottom: 30px;
    flex-wrap: wrap;
}

.tab-btn {
    flex: 1;
    padding: 15px 20px;
    font-size: 1.1em;
    font-weight: bold;
    border: 3px solid #667eea;
    background: white;
    color: #667eea;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s;
    min-width: 150px;
}

.tab-btn:hover {
    background: #f0f0f0;
    transform: translateY(-2px);
}

.tab-btn.active {
    background: #667eea;
    color: white;
}

/* Tab Content */
.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

.tab-content h2 {
    color: #667eea;
    margin-bottom: 10px;
    font-size: 2em;
}

.instruction {
    color: #666;
    margin-bottom: 20px;
    font-size: 1.1em;
}

/* Coins */
.coin {
    width: 70px;
    height: 70px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    font-size: 14px;
    color: white;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
    border: 3px solid rgba(255, 255, 255, 0.3);
    cursor: pointer;
    transition: transform 0.2s, opacity 0.3s;
}

.coin:hover {
    transform: scale(1.1);
}

.cent-1 {
    background: linear-gradient(135deg, #8B4513, #D2691E);
}

.cent-2 {
    background: linear-gradient(135deg, #CD7F32, #E9967A);
}

.cent-5 {
    background: linear-gradient(135deg, #8B4513, #D2691E);
}

.cent-10 {
    background: linear-gradient(135deg, #FFD700, #FFA500);
}

.cent-20 {
    background: linear-gradient(135deg, #FFD700, #FFA500);
}

.cent-50 {
    background: linear-gradient(135deg, #FFD700, #FFA500);
}

.euro-1 {
    background: linear-gradient(135deg, #C0C0C0, #E8E8E8);
    color: #333;
}

.euro-2 {
    background: linear-gradient(135deg, #C0C0C0, #E8E8E8);
    color: #333;
    border: 3px solid #FFD700;
}

/* Bills */
.bill {
    width: 110px;
    height: 55px;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    font-size: 16px;
    color: white;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
    cursor: pointer;
    transition: transform 0.2s, opacity 0.3s;
}

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

.bill-5 {
    background: linear-gradient(135deg, #808080, #A9A9A9);
}

.bill-10 {
    background: linear-gradient(135deg, #DC143C, #FF6347);
}

.bill-20 {
    background: linear-gradient(135deg, #4169E1, #6495ED);
}

.bill-50 {
    background: linear-gradient(135deg, #FF8C00, #FFA500);
}

/* Coin Builder */
.coin-builder-area {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
}

.builder-column h3 {
    color: #667eea;
    margin-bottom: 15px;
}

.coin-selector {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.coin-option {
    display: flex;
    align-items: center;
    gap: 15px;
    padding: 10px;
    background: #f5f5f5;
    border-radius: 10px;
}

.add-coin-btn {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: #667eea;
    color: white;
    border: none;
    font-size: 24px;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.2s;
}

.add-coin-btn:hover {
    background: #5568d3;
    transform: scale(1.1);
}

.add-coin-btn:active {
    transform: scale(0.95);
}

.coin-collection {
    min-height: 200px;
    background: #f9f9f9;
    border: 2px dashed #667eea;
    border-radius: 10px;
    padding: 15px;
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    align-content: flex-start;
}

.total-display {
    margin: 20px 0;
    padding: 15px;
    background: #667eea;
    color: white;
    border-radius: 10px;
    text-align: center;
    font-size: 1.5em;
}

.clear-btn {
    width: 100%;
    padding: 12px;
    background: #dc3545;
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1em;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.2s;
}

.clear-btn:hover {
    background: #c82333;
    transform: translateY(-2px);
}

.suggestion {
    margin-top: 20px;
    padding: 15px;
    background: #fff3cd;
    border: 2px solid #ffc107;
    border-radius: 10px;
    color: #856404;
    font-weight: bold;
    display: none;
}

.suggestion.show {
    display: block;
}

/* Money Sandbox */
.sandbox-area {
    width: 100%;
}

.sandbox-wallet h3,
.sandbox-controls h3 {
    color: #667eea;
    margin-bottom: 15px;
}

.money-display {
    min-height: 200px;
    background: #f9f9f9;
    border: 2px dashed #667eea;
    border-radius: 10px;
    padding: 15px;
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    align-content: flex-start;
}

.money-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(130px, 1fr));
    gap: 15px;
    margin-bottom: 20px;
}

.money-btn {
    padding: 10px;
    background: white;
    border: 3px solid #667eea;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
}

.money-btn:hover {
    background: #f0f0f0;
    transform: translateY(-2px);
}

.money-btn:active {
    transform: scale(0.95);
}

.action-buttons {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.action-btn {
    padding: 12px;
    background: #28a745;
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1em;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.2s;
}

.action-btn:hover {
    background: #218838;
    transform: translateY(-2px);
}

.action-btn:disabled {
    background: #ccc;
    cursor: not-allowed;
    transform: none;
}

/* Shop */
.shop-area {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 30px;
}

.shop-items h3,
.shop-checkout h3 {
    color: #667eea;
    margin-bottom: 15px;
}

.items-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
    gap: 15px;
}

.shop-item {
    background: white;
    border: 3px solid #667eea;
    border-radius: 10px;
    padding: 15px;
    text-align: center;
    transition: all 0.2s;
}

.shop-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
}

.item-image {
    font-size: 3em;
    margin-bottom: 10px;
}

.item-name {
    font-weight: bold;
    color: #333;
    margin-bottom: 5px;
}

.item-price {
    color: #667eea;
    font-size: 1.2em;
    font-weight: bold;
    margin-bottom: 10px;
}

.buy-btn {
    width: 100%;
    padding: 8px;
    background: #667eea;
    color: white;
    border: none;
    border-radius: 5px;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.2s;
}

.buy-btn:hover {
    background: #5568d3;
}

.buy-btn:disabled {
    background: #ccc;
    cursor: not-allowed;
}

.transaction-area {
    background: #f9f9f9;
    border: 2px solid #667eea;
    border-radius: 10px;
    padding: 15px;
    margin-top: 20px;
}

.transaction-info {
    margin-bottom: 15px;
}

.transaction-info p {
    margin-bottom: 5px;
}

.payment-area h4,
.change-area h4 {
    color: #667eea;
    margin-bottom: 10px;
}

.payment-buttons {
    display: flex;
    gap: 10px;
    margin-top: 15px;
}

.payment-buttons button {
    flex: 1;
}

.change-area {
    margin-top: 20px;
    padding-top: 20px;
    border-top: 2px solid #667eea;
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    z-index: 1000;
}

.modal.show {
    display: flex;
    align-items: center;
    justify-content: center;
}

.modal-content {
    background: white;
    border-radius: 20px;
    padding: 30px;
    max-width: 600px;
    width: 90%;
    max-height: 80vh;
    overflow-y: auto;
}

.modal-content h3 {
    color: #667eea;
    margin-bottom: 20px;
    text-align: center;
}

.modal-money-btn {
    padding: 10px;
    background: white;
    border: 3px solid #667eea;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
}

.modal-money-btn:hover {
    background: #f0f0f0;
    transform: scale(1.05);
}

.modal-money-btn:active {
    transform: scale(0.95);
}

/* Responsive Design */
@media (max-width: 768px) {
    .coin-builder-area,
    .sandbox-area,
    .shop-area,
    .shop-area-new {
        grid-template-columns: 1fr;
    }

    .tabs {
        flex-direction: column;
    }

    .tab-btn {
        min-width: unset;
    }

    h1 {
        font-size: 1.8em;
    }

    .money-grid {
        grid-template-columns: repeat(auto-fill, minmax(100px, 1fr));
    }

    .items-grid {
        grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
    }
    
    .coin-selector-grid {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .money-grid-compact {
        grid-template-columns: repeat(5, 1fr);
    }
    
    .floating-menu {
        min-width: 90%;
    }
    
    .checkout-modal-content {
        max-width: 95%;
    }
    
    .checkout-item-info {
        flex-direction: column;
        text-align: center;
    }
}

/* Animations */
@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.tab-content.active {
    animation: slideIn 0.3s ease-out;
}

@keyframes bounce {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.2);
    }
}

.coin.added,
.bill.added {
    animation: bounce 0.3s;
}

/* ===== NEW COIN BUILDER STYLES ===== */
.coin-selector-grid {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 15px;
    margin-bottom: 20px;
}

.select-coin-btn {
    padding: 10px;
    background: white;
    border: 3px solid #667eea;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s;
}

.select-coin-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.3);
}

.select-coin-btn.selected {
    background: #667eea;
    border-color: #5568d3;
    box-shadow: 0 0 20px rgba(102, 126, 234, 0.5);
}

.breakdown-display {
    min-height: 300px;
    background: #f9f9f9;
    border: 2px dashed #667eea;
    border-radius: 10px;
    padding: 20px;
}

.breakdown-header {
    color: #667eea;
    font-size: 1.2em;
    margin-bottom: 20px;
    text-align: center;
}

.breakdown-option {
    background: white;
    border: 2px solid #667eea;
    border-radius: 10px;
    padding: 15px;
    margin-bottom: 15px;
    transition: all 0.3s;
}

.breakdown-option:hover {
    transform: translateX(5px);
    box-shadow: 0 3px 10px rgba(0, 0, 0, 0.1);
}

.breakdown-description {
    font-weight: bold;
    color: #667eea;
    margin-bottom: 10px;
    font-size: 1.1em;
}

.breakdown-visualization {
    display: grid;
    grid-template-columns: repeat(10, 1fr);
    gap: 8px;
    padding: 10px;
    background: #f5f5f5;
    border-radius: 8px;
}

.empty-message {
    text-align: center;
    color: #999;
    font-size: 1.2em;
    padding: 50px 20px;
}

/* Small coins and bills */
.coin-small {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    font-size: 11px;
    color: white;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
    border: 2px solid rgba(255, 255, 255, 0.3);
}

.bill-small {
    width: 80px;
    height: 40px;
    border-radius: 5px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    font-size: 14px;
    color: white;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
}

/* ===== NEW MONEY SANDBOX STYLES ===== */
.sandbox-area {
    width: 100%;
}

.sandbox-main {
    width: 100%;
}

.money-display-large {
    min-height: 250px;
    background: #f9f9f9;
    border: 3px dashed #667eea;
    border-radius: 15px;
    padding: 20px;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(70px, 1fr));
    gap: 15px;
    align-content: flex-start;
}

.coin.selected,
.bill.selected {
    border: 4px solid #ffd700;
    box-shadow: 0 0 20px rgba(255, 215, 0, 0.6);
    transform: scale(1.1);
    animation: pulse 0.5s ease-in-out;
}

@keyframes pulse {
    0%, 100% {
        transform: scale(1.1);
    }
    50% {
        transform: scale(1.15);
    }
}

.money-grid-compact {
    display: grid;
    grid-template-columns: repeat(10, 1fr);
    gap: 10px;
    margin: 20px 0;
}

.money-btn-compact {
    padding: 8px;
    background: white;
    border: 2px solid #667eea;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s;
}

.money-btn-compact:hover {
    transform: scale(1.05);
    box-shadow: 0 3px 10px rgba(0, 0, 0, 0.2);
}

/* Floating Action Menu */
.floating-menu {
    position: fixed;
    bottom: -100px;
    left: 50%;
    transform: translateX(-50%);
    background: white;
    border-radius: 20px 20px 0 0;
    box-shadow: 0 -5px 30px rgba(0, 0, 0, 0.3);
    padding: 20px 30px;
    transition: bottom 0.3s ease-out;
    z-index: 1000;
    min-width: 400px;
}

.floating-menu.show {
    bottom: 0;
}

.floating-menu.exchanging {
    animation: exchange-shake 0.5s;
}

.floating-menu.removing {
    animation: remove-fade 0.3s;
}

@keyframes exchange-shake {
    0%, 100% { transform: translateX(-50%) rotate(0deg); }
    25% { transform: translateX(-50%) rotate(-5deg); }
    75% { transform: translateX(-50%) rotate(5deg); }
}

@keyframes remove-fade {
    0% { opacity: 1; }
    100% { opacity: 0.5; }
}

.floating-menu-content {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.floating-menu-header {
    display: flex;
    justify-content: space-between;
    font-weight: bold;
    color: #667eea;
    font-size: 1.1em;
}

.floating-menu-actions {
    display: flex;
    gap: 10px;
}

.float-action-btn {
    flex: 1;
    padding: 12px 20px;
    border: none;
    border-radius: 10px;
    font-size: 1em;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

.exchange-btn {
    background: #28a745;
    color: white;
}

.exchange-btn:hover:not(:disabled) {
    background: #218838;
    transform: translateY(-2px);
}

.exchange-btn:disabled {
    background: #ccc;
    cursor: not-allowed;
}

.remove-btn {
    background: #dc3545;
    color: white;
}

.remove-btn:hover {
    background: #c82333;
    transform: translateY(-2px);
}

.btn-icon {
    font-size: 1.3em;
}

/* ===== NEW FAKE SHOP STYLES ===== */
.shop-area-new {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
}

.shop-wallet-section {
    width: 100%;
}

.shop-items-full {
    width: 100%;
}


.checkout-modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.7);
    z-index: 2000;
    align-items: center;
    justify-content: center;
    animation: fadeIn 0.3s;
}

.checkout-modal.show {
    display: flex;
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

.checkout-modal-content {
    background: white;
    border-radius: 20px;
    max-width: 600px;
    width: 90%;
    max-height: 90vh;
    overflow-y: auto;
    animation: slideUp 0.3s;
}

@keyframes slideUp {
    from {
        transform: translateY(50px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.checkout-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 30px;
    border-bottom: 2px solid #667eea;
}

.checkout-header h3 {
    color: #667eea;
    margin: 0;
}

.close-checkout {
    background: none;
    border: none;
    font-size: 2em;
    cursor: pointer;
    color: #999;
    transition: color 0.2s;
}

.close-checkout:hover {
    color: #dc3545;
}

.checkout-body {
    padding: 30px;
}

.checkout-item-info {
    display: flex;
    gap: 20px;
    align-items: center;
    margin-bottom: 30px;
    padding: 20px;
    background: #f9f9f9;
    border-radius: 15px;
}

.checkout-item-large {
    font-size: 4em;
}

.checkout-details p {
    margin: 5px 0;
    font-size: 1.1em;
}

.payment-section {
    margin-bottom: 30px;
}

.payment-section h4 {
    color: #667eea;
    margin-bottom: 15px;
}

.payment-money-display {
    min-height: 150px;
    background: #f9f9f9;
    border: 2px dashed #667eea;
    border-radius: 10px;
    padding: 15px;
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    align-content: flex-start;
    margin-bottom: 15px;
}

.payment-money-display .coin.available,
.payment-money-display .bill.available {
    opacity: 0.4;
    transition: all 0.2s;
}

.payment-money-display .coin.available:hover,
.payment-money-display .bill.available:hover {
    opacity: 0.7;
    transform: scale(1.05);
}

.payment-money-display .coin.in-payment,
.payment-money-display .bill.in-payment {
    border: 3px solid #28a745;
    animation: popIn 0.3s;
}

@keyframes popIn {
    0% {
        transform: scale(0);
    }
    50% {
        transform: scale(1.2);
    }
    100% {
        transform: scale(1);
    }
}

.payment-total {
    text-align: center;
    font-size: 1.3em;
    color: #667eea;
    margin-bottom: 15px;
}

.checkout-buttons {
    display: flex;
    gap: 10px;
}

.pay-btn-large {
    width: 100%;
    padding: 15px;
    background: #28a745;
    color: white;
    border: none;
    border-radius: 10px;
    font-size: 1.2em;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.2s;
}

.pay-btn-large:hover:not(:disabled) {
    background: #218838;
    transform: translateY(-2px);
}

.pay-btn-large:disabled {
    background: #ccc;
    cursor: not-allowed;
}

/* Change Section */
.change-section {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 15px;
    padding: 30px;
    color: white;
    opacity: 0;
    transition: opacity 0.3s;
}

.change-section.show {
    opacity: 1;
}

.change-animation {
    text-align: center;
}

.change-title {
    font-size: 2em;
    font-weight: bold;
    margin-bottom: 20px;
    animation: bounce 1s infinite;
}

.change-money-display {
    min-height: 120px;
    background: rgba(255, 255, 255, 0.2);
    border: 2px dashed white;
    border-radius: 10px;
    padding: 20px;
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    justify-content: center;
    align-items: center;
    margin-bottom: 20px;
}

.change-money-display .coin,
.change-money-display .bill {
    animation: popIn 0.5s;
}

.change-total {
    font-size: 1.5em;
    margin-bottom: 20px;
}

.collect-btn {
    width: 100%;
    padding: 15px;
    background: white;
    color: #667eea;
    border: none;
    border-radius: 10px;
    font-size: 1.2em;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.2s;
}

.collect-btn:hover {
    background: #f0f0f0;
    transform: scale(1.05);
}

/* Responsive adjustments */
@media (max-width: 768px) {
    .floating-menu {
        min-width: 90%;
    }
    
    .checkout-modal-content {
        max-width: 95%;
    }
    
    .checkout-item-info {
        flex-direction: column;
        text-align: center;
    }
}

/* Money animations */
.fading-out {
    animation: fadeOut 0.3s forwards;
}

@keyframes fadeOut {
    from {
        opacity: 1;
        transform: scale(1);
    }
    to {
        opacity: 0;
        transform: scale(0.5);
    }
}

.pop-in {
    animation: popIn 0.4s ease-out;
}

@keyframes popIn {
    0% {
        opacity: 0;
        transform: scale(0);
    }
    50% {
        transform: scale(1.2);
    }
    100% {
        opacity: 1;
        transform: scale(1);
    }
}

/* Exchange preview in floating menu */
.exchange-preview {
    display: none;
    align-items: center;
    justify-content: center;
    margin-left: 10px;
    padding: 5px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 8px;
}

/* Split preview in floating menu */
.split-preview {
    display: none;
    align-items: center;
    justify-content: center;
    margin-left: 10px;
    padding: 5px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 8px;
    gap: 3px;
}

.float-action-btn {
    position: relative;
}

.split-btn {
    background: #17a2b8;
    color: white;
}

.split-btn:hover:not(:disabled) {
    background: #138496;
    transform: translateY(-2px);
}

.split-btn:disabled {
    background: #ccc;
    cursor: not-allowed;
}

.split-btn.enabled {
    background: #17a2b8;
}

/* ===== CHALLENGES STYLES ===== */
.challenge-mode-selector {
    display: flex;
    gap: 15px;
    margin-bottom: 30px;
    justify-content: center;
}

.challenge-mode-btn {
    padding: 15px 30px;
    font-size: 1.1em;
    font-weight: bold;
    border: 3px solid #667eea;
    background: white;
    color: #667eea;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s;
}

.challenge-mode-btn:hover {
    background: #f0f0f0;
    transform: translateY(-2px);
}

.challenge-mode-btn.active {
    background: #667eea;
    color: white;
}

.challenge-container {
    display: none;
}

.challenge-container.active {
    display: block;
}

.challenge-info {
    text-align: center;
    margin-bottom: 30px;
    padding: 20px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border-radius: 15px;
}

.challenge-info h3 {
    font-size: 1.8em;
    margin-bottom: 10px;
}

.challenge-info p {
    font-size: 1.1em;
    opacity: 0.95;
}

.challenge-item-display {
    display: flex;
    justify-content: center;
    margin-bottom: 30px;
}

.challenge-item {
    background: white;
    border: 4px solid #667eea;
    border-radius: 15px;
    padding: 30px;
    text-align: center;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.15);
    min-width: 200px;
}

.challenge-item-emoji {
    font-size: 5em;
    margin-bottom: 15px;
}

.challenge-item-name {
    font-size: 1.5em;
    font-weight: bold;
    color: #333;
    margin-bottom: 10px;
}

.challenge-item-price {
    font-size: 2em;
    font-weight: bold;
    color: #667eea;
}

.challenge-section {
    margin-bottom: 25px;
}

.challenge-section h4 {
    color: #667eea;
    margin-bottom: 15px;
    font-size: 1.2em;
}

.challenge-money-display {
    min-height: 150px;
    background: #f9f9f9;
    border: 3px dashed #667eea;
    border-radius: 10px;
    padding: 20px;
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    align-content: flex-start;
    justify-content: center;
}

.challenge-money-display.payment-area {
    background: #fff9e6;
    border-color: #ffc107;
}

.challenge-money-display .coin,
.challenge-money-display .bill {
    cursor: pointer;
    transition: all 0.2s;
}

.challenge-money-display .coin:hover,
.challenge-money-display .bill:hover {
    transform: scale(1.1);
}

.challenge-total {
    text-align: center;
    font-size: 1.3em;
    color: #667eea;
    margin-top: 15px;
    padding: 10px;
    background: white;
    border-radius: 8px;
}

.challenge-buttons {
    display: flex;
    gap: 15px;
    justify-content: center;
    margin: 30px 0;
}

.challenge-btn {
    padding: 15px 40px;
    font-size: 1.2em;
    font-weight: bold;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s;
}

.check-btn {
    background: #28a745;
    color: white;
}

.check-btn:hover {
    background: #218838;
    transform: translateY(-3px);
    box-shadow: 0 5px 15px rgba(40, 167, 69, 0.3);
}

.next-btn {
    background: #667eea;
    color: white;
}

.next-btn:hover {
    background: #5568d3;
    transform: translateY(-3px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.3);
}

.challenge-feedback {
    display: none;
    padding: 20px;
    border-radius: 10px;
    text-align: center;
    font-size: 1.3em;
    font-weight: bold;
    margin-top: 20px;
    animation: slideIn 0.3s ease-out;
}

.challenge-feedback.show {
    display: block;
}

.challenge-feedback.success {
    background: #d4edda;
    color: #155724;
    border: 3px solid #28a745;
}

.challenge-feedback.error {
    background: #f8d7da;
    color: #721c24;
    border: 3px solid #dc3545;
}

/* Give Change Scenario */
.change-scenario {
    margin-bottom: 30px;
    padding: 25px;
    background: white;
    border: 3px solid #667eea;
    border-radius: 15px;
}

.scenario-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 20px;
}

.scenario-item {
    text-align: center;
    padding: 15px;
    background: #f9f9f9;
    border-radius: 10px;
}

.scenario-item.highlight {
    background: #fff3cd;
    border: 2px solid #ffc107;
}

.scenario-label {
    font-weight: bold;
    color: #666;
    margin-bottom: 10px;
    font-size: 0.9em;
}

.scenario-emoji {
    font-size: 3em;
    margin: 10px 0;
}

.scenario-value {
    font-size: 1.1em;
    color: #333;
    font-weight: bold;
}

.scenario-value.large {
    font-size: 1.5em;
    color: #667eea;
}

@media (max-width: 768px) {
    .challenge-mode-selector {
        flex-direction: column;
    }
    
    .scenario-row {
        grid-template-columns: 1fr;
    }
    
    .challenge-buttons {
        flex-direction: column;
    }
    
    .challenge-btn {
        width: 100%;
    }
}