:root {
    --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --card-bg: rgba(255, 255, 255, 0.95);
    --shadow-sm: 0 4px 6px rgba(0, 0, 0, 0.07);
    --shadow-lg: 0 20px 35px -10px rgba(0, 0, 0, 0.15);
    --border-radius: 24px;
    --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}

body.modal-open { overflow: hidden; }

.upg-container {
    max-width: 1400px;
    margin: 2rem auto;
    padding: 2rem;
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: linear-gradient(145deg, #f5f7ff 0%, #eef2ff 100%);
    border-radius: 48px;
    position: relative;
}

.upg-header {
    text-align: center;
    margin-bottom: 3rem;
}
.upg-header h2 {
    font-size: 2.8rem;
    font-weight: 800;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

.upg-payment-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1.8rem;
}

.upg-card {
    background: var(--card-bg);
    border-radius: var(--border-radius);
    padding: 1.8rem;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: var(--shadow-sm);
    border: 1px solid rgba(255,255,255,0.3);
}
.upg-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-lg);
}
.upg-card-logo {
    width: 80px;
    height: 80px;
    margin: 0 auto 1rem;
    object-fit: contain;
}
.upg-card h3 { margin: 0.5rem 0; font-size: 1.3rem; }
.payment-desc { font-size: 0.8rem; color: #6b7280; margin-top: 0.25rem; }

/* MODALS - fully centered */
.upg-modal {
    display: none;
    position: fixed;
    z-index: 9999;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.75);
    backdrop-filter: blur(8px);
    align-items: center;
    justify-content: center;
}
.upg-modal-content {
    background: white;
    margin: 20px auto;
    padding: 2rem;
    border-radius: 32px;
    max-width: 560px;
    width: 90%;
    max-height: 85vh;
    overflow-y: auto;
    position: relative;
    animation: slideUp 0.3s ease;
    box-shadow: 0 25px 50px -12px rgba(0,0,0,0.25);
}
@keyframes slideUp {
    from { transform: translateY(40px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}
.upg-modal-close {
    position: absolute;
    right: 1.2rem;
    top: 1rem;
    font-size: 1.8rem;
    cursor: pointer;
    color: #aaa;
    transition: 0.2s;
    z-index: 10;
}
.upg-modal-close:hover { color: #333; }

/* Amount step modal */
.upg-amount-input {
    width: 100%;
    padding: 1rem;
    font-size: 1.2rem;
    border: 2px solid #e5e7eb;
    border-radius: 60px;
    margin: 1rem 0;
    text-align: center;
}
.upg-modal-buttons {
    display: flex;
    gap: 1rem;
    margin-top: 1.5rem;
}
.upg-btn {
    background: var(--primary-gradient);
    color: white;
    border: none;
    padding: 0.8rem 1.2rem;
    border-radius: 60px;
    font-weight: 600;
    cursor: pointer;
    flex: 1;
    transition: 0.2s;
}
.upg-btn:hover { transform: translateY(-2px); filter: brightness(1.05); }
.cancel-btn { background: linear-gradient(135deg, #ef4444, #dc2626); }

/* Final payment details modal */
.modal-header-with-logo {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
    border-bottom: 2px solid #eef2ff;
    padding-bottom: 1rem;
}
.modal-logo {
    width: 55px;
    height: 55px;
    object-fit: contain;
}
.upg-instructions {
    background: #f8fafc;
    padding: 1rem;
    border-radius: 20px;
    margin: 1rem 0;
    text-align: left;
    border-left: 4px solid #667eea;
}
.upg-instructions ol { padding-left: 1.2rem; margin: 0.5rem 0; }
.upg-instructions li { margin: 0.6rem 0; font-size: 0.9rem; line-height: 1.4; }
.email-highlight {
    background: #e0e7ff;
    padding: 0.2rem 0.5rem;
    border-radius: 8px;
    font-family: monospace;
    display: inline-block;
    word-break: break-all;
}
.copy-email-btn {
    background: #667eea;
    border: none;
    color: white;
    padding: 0.2rem 0.6rem;
    border-radius: 20px;
    margin-left: 0.5rem;
    cursor: pointer;
}
.crypto-address {
    background: #f3f4f6;
    padding: 1rem;
    border-radius: 16px;
    word-break: break-all;
    font-family: monospace;
    margin: 1rem 0;
}
.qr-code { text-align: center; margin: 1rem 0; }
.qr-code img { max-width: 180px; border-radius: 16px; }
.copy-toast {
    position: fixed;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    background: #1e293b;
    color: white;
    padding: 0.6rem 1.2rem;
    border-radius: 50px;
    z-index: 10000;
    animation: fadeOut 2s forwards;
}
@keyframes fadeOut {
    0% { opacity: 1; }
    70% { opacity: 1; }
    100% { opacity: 0; visibility: hidden; }
}
.spinner {
    width: 40px;
    height: 40px;
    border: 3px solid #e2e8f0;
    border-top-color: #667eea;
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
    margin: 1rem auto;
}
@keyframes spin { to { transform: rotate(360deg); } }

@media (max-width: 640px) {
    .upg-container { padding: 1rem; }
    .upg-header h2 { font-size: 1.8rem; }
    .upg-modal-content { padding: 1.2rem; width: 95%; max-height: 80vh; }
    .modal-logo { width: 45px; height: 45px; }
    .upg-instructions li { font-size: 0.8rem; }
}