:root {
    --primary: #dc2626;
    --primary-dark: #b91c1c;
    --secondary: #ef4444;
    --accent: #fef2f2;
    --dark: #111827;
    --light: #ffffff;
    --gray-50: #fafafa;
    --gray-100: #f4f4f5;
    --gray-200: #e4e4e7;
    --gray-300: #d4d4d8;
    --gray-800: #27272a;
    --success: #22c55e;
    --error: #ef4444;
    --warning: #f59e0b;
    --shadow-offset: 4px;
}

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

body {
    background-color: var(--gray-50);
    color: var(--dark);
    line-height: 1.6;
}

.container {
    width: 100%;
    max-width: 1440px;
    margin: 0 auto;
}

/* Header Styles - Neo-brutalism */
.header {
    background: var(--primary);
    color: var(--light);
    padding: 3rem 0;
    text-align: center;
    position: relative;
    margin-bottom: 2rem;
    border: 3px solid var(--dark);
    box-shadow: var(--shadow-offset) var(--shadow-offset) 0 var(--dark);
    border-radius: 0 0 1rem 1rem;
}

.header h1 {
    font-size: 2.75rem;
    font-weight: 800;
    margin-bottom: 0.5rem;
    text-transform: uppercase;
}

.header p {
    font-size: 1.2rem;
    opacity: 0.9;
    font-weight: 500;
}

/* Stats Container */
.stats-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
    margin: 0 1.5rem 2rem;
}

.stat-card {
    background: var(--light);
    border: 2px solid var(--dark);
    box-shadow: var(--shadow-offset) var(--shadow-offset) 0 var(--dark);
    border-radius: 0.5rem;
    padding: 1.75rem;
    transition: transform 0.2s;
}

.stat-card:hover {
    transform: translate(-2px, -2px);
    box-shadow: calc(var(--shadow-offset) + 2px) calc(var(--shadow-offset) + 2px) 0 var(--dark);
}

.stat-card h3 {
    color: var(--gray-800);
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.stat-card p {
    color: var(--primary);
    font-size: 1.75rem;
    font-weight: 700;
}

/* Main Content */
.main-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
    gap: 2rem;
    margin: 0 1.5rem 2.5rem;
}

.form-group {
    background: var(--light);
    border: 2px solid var(--dark);
    box-shadow: var(--shadow-offset) var(--shadow-offset) 0 var(--dark);
    border-radius: 0.5rem;
    padding: 2rem 1.5rem;
}

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

label {
    display: block;
    font-weight: 600;
    color: var(--gray-800);
    margin-bottom: 0.5rem;
    text-transform: uppercase;
    font-size: 0.9rem;
    letter-spacing: 0.5px;
}

input[type="file"],
input[type="text"],
input[type="number"],
textarea {
    width: 100%;
    padding: 0.875rem 1rem;
    border: 2px solid var(--dark);
    border-radius: 0.5rem;
    font-size: 1rem;
    transition: all 0.2s;
    background: var(--gray-50);
}

input:focus,
textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 4px 4px 0 var(--primary);
    transform: translate(-2px, -2px);
}

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

button {
    background: var(--primary);
    color: var(--light);
    padding: 0.875rem 1.75rem;
    border: 2px solid var(--dark);
    box-shadow: var(--shadow-offset) var(--shadow-offset) 0 var(--dark);
    border-radius: 0.5rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    font-size: 0.9rem;
}

button:hover {
    transform: translate(-2px, -2px);
    box-shadow: calc(var(--shadow-offset) + 2px) calc(var(--shadow-offset) + 2px) 0 var(--dark);
}

button:active {
    transform: translate(0, 0);
    box-shadow: var(--shadow-offset) var(--shadow-offset) 0 var(--dark);
}

/* QR Code Container */
#qrcode {
    background: var(--light);
    padding: 2rem 0;
    border: 2px solid var(--dark);
    box-shadow: var(--shadow-offset) var(--shadow-offset) 0 var(--dark);
    border-radius: 0.5rem;
    text-align: center;
    min-height: 200px;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* Chart Container */
.chart-container {
    background: var(--light);
    border: 2px solid var(--dark);
    box-shadow: var(--shadow-offset) var(--shadow-offset) 0 var(--dark);
    border-radius: 0.5rem;
    padding: 1.75rem 0;
    margin: 0 1.5rem 2.5rem;
    height: 400px;
}

/* Transaction History */
.history-container {
    background: var(--light);
    border: 2px solid var(--dark);
    box-shadow: var(--shadow-offset) var(--shadow-offset) 0 var(--dark);
    border-radius: 0.5rem;
    overflow: hidden;
    margin: 0 1.5rem;
}

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

.history-table th {
    background: var(--gray-100);
    padding: 1.25rem 1rem;
    text-align: left;
    font-weight: 600;
    color: var(--gray-800);
    text-transform: uppercase;
    font-size: 0.9rem;
    letter-spacing: 0.5px;
    border-bottom: 2px solid var(--dark);
}

.history-table td {
    padding: 1.25rem 1rem;
    border-bottom: 1px solid var(--gray-200);
}

.history-table tr:hover {
    background: var(--gray-50);
}

/* Merchant Suggestions */
.merchant-suggestions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    margin-top: 0.75rem;
}

.merchant-suggestion-btn {
    background: var(--gray-100);
    color: var(--dark);
    padding: 0.5rem 1rem;
    border: 2px solid var(--dark);
    box-shadow: 2px 2px 0 var(--dark);
    border-radius: 0.5rem;
    font-size: 0.875rem;
    cursor: pointer;
    transition: all 0.2s;
}

.merchant-suggestion-btn:hover {
    background: var(--primary);
    color: var(--light);
    transform: translate(-1px, -1px);
    box-shadow: 3px 3px 0 var(--dark);
}

/* Toast Notifications */
.toast {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    padding: 1rem 1.5rem;
    border: 2px solid var(--dark);
    box-shadow: var(--shadow-offset) var(--shadow-offset) 0 var(--dark);
    border-radius: 0.5rem;
    color: var(--light);
    font-weight: 500;
    opacity: 0;
    transform: translateY(1rem);
    transition: all 0.3s;
    z-index: 1000;
}

.toast.success {
    background: var(--success);
}

.toast.error {
    background: var(--error);
}

.toast.warning {
    background: var(--warning);
}

.toast.show {
    opacity: 1;
    transform: translateY(0);
}

/* Loading Animation */
.loading {
    width: 20px;
    height: 20px;
    border: 2px solid var(--light);
    border-radius: 50%;
    border-top-color: transparent;
    animation: spin 1s linear infinite;
}

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

/* Responsive Design */
@media (max-width: 768px) {
    :root {
        --shadow-offset: 3px;
    }
    
    .header {
        padding: 2rem 1rem;
    }

    .header h1 {
        font-size: 2rem;
    }
    
    .main-content {
        grid-template-columns: 1fr;
        margin: 0 1rem 2rem;
    }
    
    .stats-container {
        margin: 0 1rem 2rem;
    }
    
    .chart-container,
    .history-container {
        margin: 0 1rem 2rem;
    }
    
    .form-group {
        padding: 1.5rem 1rem;
    }
    
    .button-container {
        flex-direction: column;
    }
    
    button {
        width: 100%;
    }
    
    .toast {
        left: 1rem;
        right: 1rem;
        bottom: 1rem;
        text-align: center;
    }

    .stats-container {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    :root {
        --shadow-offset: 2px;
    }

    .header h1 {
        font-size: 1.75rem;
    }

    .stat-card p {
        font-size: 1.5rem;
    }

    .form-group {
        padding: 1.25rem 0.75rem;
    }
    
    .main-content,
    .stats-container,
    .chart-container,
    .history-container {
        margin: 0 0.75rem 2rem;
    }
}