:root {
    --primary: #10b981;
    --primary-dark: #059669;
    --primary-light: #d1fae5;
    --secondary: #f59e0b;
    --secondary-dark: #d97706;
    --danger: #ef4444;
    --danger-dark: #dc2626;
    --success: #10b981;
    --warning: #f59e0b;
    --info: #3b82f6;
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: white;
    min-height: 100vh;
    padding: 20px;
    color: var(--gray-900);
}

.container {
    max-width: 480px;
    margin: 0 auto;
    background: white;
    border-radius: 24px;
    padding: 30px 20px;
    box-shadow: var(--shadow-md);
    animation: slideUp 0.3s ease-out;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.header {
    text-align: center;
    margin-bottom: 40px;
}

.header h1 {
    font-size: 32px;
    color: var(--gray-900);
    margin-bottom: 10px;
    font-weight: 700;
}

.header p {
    color: var(--gray-600);
    font-size: 16px;
}

/* App Branding */
.app-logo {
    font-size: 80px;
    margin-bottom: 20px;
    display: inline-block;
    animation: bounce 2s infinite;
}

@keyframes bounce {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

.app-name {
    font-size: 36px;
    font-weight: 800;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 10px;
}

.app-tagline {
    color: var(--gray-600);
    font-size: 16px;
    font-weight: 500;
}

.role-selection h2 {
    text-align: center;
    color: #2d3748;
    margin-bottom: 30px;
    font-size: 24px;
}

.role-card {
    display: block;
    background: white;
    border: 2px solid var(--gray-200);
    border-radius: 20px;
    padding: 35px 30px;
    margin-bottom: 20px;
    text-align: center;
    text-decoration: none;
    transition: all 0.3s ease;
    cursor: pointer;
    box-shadow: var(--shadow);
    position: relative;
    overflow: hidden;
}

.role-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary), var(--secondary));
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

.role-card:hover::before {
    transform: scaleX(1);
}

.role-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary);
}

.role-card.buyer:hover {
    background: linear-gradient(135deg, #ecfdf5 0%, #d1fae5 100%);
}

.role-card.seller:hover {
    background: linear-gradient(135deg, #fffbeb 0%, #fef3c7 100%);
}

.role-card .icon {
    font-size: 72px;
    margin-bottom: 20px;
    display: inline-block;
    transition: transform 0.3s ease;
}

.role-card:hover .icon {
    transform: scale(1.1) rotate(5deg);
}

.role-card h3 {
    font-size: 24px;
    color: var(--gray-900);
    margin-bottom: 10px;
    font-weight: 700;
}

.role-card p {
    color: var(--gray-600);
    font-size: 16px;
    font-weight: 500;
}

.footer {
    text-align: center;
    margin-top: 50px;
    padding-top: 20px;
    border-top: 1px solid var(--gray-200);
    color: var(--gray-400);
    font-size: 13px;
}

/* Feature Cards */
.feature-card {
    display: flex;
    align-items: center;
    gap: 15px;
    padding: 20px;
    background: white;
    border-radius: 16px;
    box-shadow: var(--shadow-sm);
    transition: all 0.3s ease;
}

.feature-card:hover {
    box-shadow: var(--shadow-md);
    transform: translateX(5px);
}

.feature-icon {
    font-size: 40px;
    flex-shrink: 0;
}

.feature-content strong {
    display: block;
    color: var(--gray-900);
    margin-bottom: 5px;
    font-weight: 600;
}

.feature-content span {
    color: var(--gray-600);
    font-size: 14px;
}

/* Mobile-first large buttons */
.btn {
    display: block;
    width: 100%;
    padding: 20px;
    font-size: 20px;
    font-weight: 600;
    border: none;
    border-radius: 12px;
    cursor: pointer;
    text-align: center;
    text-decoration: none;
    transition: all 0.3s ease;
    margin-bottom: 15px;
    min-height: 70px;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: white;
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-2px);
}

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

.btn-secondary {
    background: linear-gradient(135deg, var(--secondary) 0%, var(--secondary-dark) 100%);
    color: white;
    box-shadow: var(--shadow-md);
}

.btn-secondary:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-2px);
}

.btn-danger {
    background: linear-gradient(135deg, var(--danger) 0%, var(--danger-dark) 100%);
    color: white;
    box-shadow: var(--shadow-md);
}

.btn-danger:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-2px);
}

.btn-outline {
    background: white;
    color: var(--gray-700);
    border: 2px solid var(--gray-300);
    box-shadow: var(--shadow-sm);
}

.btn-outline:hover {
    background: var(--gray-50);
    border-color: var(--primary);
    color: var(--primary);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

/* Navigation */
.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    padding-bottom: 20px;
    border-bottom: 2px solid var(--gray-200);
}

.nav .back-btn {
    font-size: 28px;
    text-decoration: none;
    color: var(--gray-600);
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 12px;
    transition: all 0.3s ease;
}

.nav .back-btn:hover {
    background: var(--gray-100);
    color: var(--primary);
}

.nav h2 {
    font-size: 22px;
    color: var(--gray-900);
    font-weight: 700;
}

.nav .menu-btn {
    font-size: 24px;
    color: var(--gray-600);
    cursor: pointer;
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 12px;
    transition: all 0.3s ease;
}

.nav .menu-btn:hover {
    background: var(--gray-100);
}

/* Cards */
.card {
    background: white;
    border: 1px solid var(--gray-200);
    border-radius: 16px;
    padding: 20px;
    margin-bottom: 15px;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
}

.card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
}

.card-title {
    font-size: 20px;
    font-weight: 600;
    color: #2d3748;
}

.card-body {
    color: #4a5568;
    line-height: 1.6;
}

/* Form elements */
.form-group {
    margin-bottom: 20px;
}

.form-label {
    display: block;
    font-size: 18px;
    font-weight: 600;
    color: #2d3748;
    margin-bottom: 10px;
}

.form-input {
    width: 100%;
    padding: 16px;
    font-size: 18px;
    border: 2px solid var(--gray-300);
    border-radius: 12px;
    transition: all 0.3s ease;
    background: var(--gray-50);
}

.form-input:focus {
    outline: none;
    border-color: var(--primary);
    background: white;
    box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.1);
}

/* Product grid */
.product-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 15px;
    margin-bottom: 20px;
}

.product-card {
    background: white;
    border: 2px solid #e2e8f0;
    border-radius: 12px;
    overflow: hidden;
    transition: all 0.3s ease;
}

.product-card:hover {
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    transform: translateY(-2px);
}

.product-image {
    width: 100%;
    height: 200px;
    background: #f7fafc;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 64px;
}

.product-info {
    padding: 15px;
}

.product-name {
    font-size: 20px;
    font-weight: 600;
    color: #2d3748;
    margin-bottom: 5px;
}

.product-price {
    font-size: 24px;
    color: #48bb78;
    font-weight: 700;
    margin-bottom: 10px;
}

.product-details {
    color: #718096;
    font-size: 14px;
    margin-bottom: 15px;
}

/* Status badges */
.badge {
    display: inline-block;
    padding: 6px 14px;
    border-radius: 20px;
    font-size: 13px;
    font-weight: 600;
    letter-spacing: 0.3px;
}

.badge-success {
    background: #d1fae5;
    color: #065f46;
}

.badge-warning {
    background: #fef3c7;
    color: #92400e;
}

.badge-danger {
    background: #fee2e2;
    color: #991b1b;
}

.badge-info {
    background: #dbeafe;
    color: #1e40af;
}

/* Stats */
.stats-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
    margin-bottom: 30px;
}

.stat-card {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: white;
    padding: 24px 20px;
    border-radius: 16px;
    text-align: center;
    box-shadow: var(--shadow-md);
    transition: all 0.3s ease;
}

.stat-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.stat-value {
    font-size: 36px;
    font-weight: 800;
    margin-bottom: 8px;
}

.stat-label {
    font-size: 14px;
    opacity: 0.95;
    font-weight: 500;
}

/* Empty state */
.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: #a0aec0;
}

.empty-state .icon {
    font-size: 64px;
    margin-bottom: 20px;
}

.empty-state h3 {
    font-size: 20px;
    color: #4a5568;
    margin-bottom: 10px;
}