:root {
            --primary: #6366f1;
            --primary-dark: #4f46e5;
            --primary-light: #a5b4fc;
            --secondary: #10b981;
            --secondary-dark: #059669;
            --accent: #f59e0b;
            --dark: #1e1b4b;
            --light: #f8fafc;
            --gray: #e2e8f0;
            --gray-dark: #475569;
            --text: #1e293b;
            --text-light: #64748b;
            --danger: #ef4444;
            --success: #10b981;
            --warning: #f59e0b;
            --info: #3b82f6;
            --shadow: 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);
            --radius: 16px;
            --radius-sm: 8px;
            --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        }

        .dark-mode {
            --bg-dark: #0f172a;
            --card-dark: #1e293b;
            --text-dark: #f1f5f9;
            --text-light-dark: #cbd5e1;
            --gray-dark: #334155;
            --shadow-dark: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -1px rgba(0, 0, 0, 0.2);
            --shadow-lg-dark: 0 10px 15px -3px rgba(0, 0, 0, 0.3), 0 4px 6px -2px rgba(0, 0, 0, 0.2);
        }

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

        body {
            background: linear-gradient(135deg, #f0f4ff 0%, #e0e7ff 100%);
            color: var(--text);
            line-height: 1.6;
            min-height: 100vh;
            padding: 20px;
            transition: var(--transition);
        }

        body.dark-mode {
            background: linear-gradient(135deg, #0f172a 0%, #1e1b4b 100%);
            color: var(--text-dark);
        }

        .container {
            max-width: 480px;
            margin: 0 auto;
        }

        .header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 24px;
        }
/* Para Birimi Seçici */
.currency-selector {
    display: flex;
    gap: 10px;
    margin-bottom: 10px;
}

.currency-option {
    padding: 8px 16px;
    border: 2px solid #334155;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: 500;
    background: #1e293b;
}

.currency-option.selected {
    background: #3b82f6;
    border-color: #3b82f6;
    color: white;
}

.currency-option:hover {
    border-color: #3b82f6;
}

/* Çift Önizleme */
.amount-previews {
    display: flex;
    gap: 15px;
    margin-top: 10px;
}

.amount-preview {
    flex: 1;
    padding: 12px;
    background: #1e293b;
    border-radius: 8px;
    border-left: 4px solid #3b82f6;
}

.amount-preview-label {
    font-size: 12px;
    color: #94a3b8;
    margin-bottom: 5px;
}

.amount-preview-value {
    font-size: 16px;
    font-weight: 600;
    color: #3b82f6;
}

        .logo {
            display: flex;
            align-items: center;
            gap: 12px;
        }

        .logo-icon {
            width: 48px;
            height: 48px;
            background: linear-gradient(135deg, var(--primary), var(--primary-dark));
            border-radius: 12px;
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            font-size: 1.5rem;
            box-shadow: var(--shadow);
        }

        .logo-text h1 {
            font-size: 1.75rem;
            font-weight: 700;
            background: linear-gradient(135deg, var(--primary), var(--dark));
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            margin-bottom: 4px;
            line-height: 1.2;
        }

        .logo-text p {
            color: var(--text-light);
            font-size: 0.875rem;
            font-weight: 500;
        }

        .dark-mode .logo-text p {
            color: var(--text-light-dark);
        }

        .theme-toggle {
            background: white;
            color: var(--primary);
            border: none;
            border-radius: 12px;
            width: 48px;
            height: 48px;
            display: flex;
            align-items: center;
            justify-content: center;
            cursor: pointer;
            transition: var(--transition);
            box-shadow: var(--shadow);
        }

        .dark-mode .theme-toggle {
            background: var(--card-dark);
            color: var(--primary-light);
        }

        .theme-toggle:hover {
            transform: rotate(15deg) scale(1.05);
            box-shadow: var(--shadow-lg);
        }

        .card {
            background: white;
            border-radius: var(--radius);
            box-shadow: var(--shadow);
            padding: 28px;
            margin-bottom: 24px;
            transition: var(--transition);
            border: 1px solid rgba(255, 255, 255, 0.8);
        }

        .dark-mode .card {
            background: var(--card-dark);
            box-shadow: var(--shadow-dark);
            border: 1px solid rgba(255, 255, 255, 0.05);
        }

        .card:hover {
            transform: translateY(-5px);
            box-shadow: var(--shadow-lg);
        }

        .dark-mode .card:hover {
            box-shadow: var(--shadow-lg-dark);
        }

        .card-header {
            margin-bottom: 24px;
            text-align: center;
        }

        .card-header h2 {
            font-size: 1.5rem;
            color: var(--dark);
            margin-bottom: 8px;
            font-weight: 700;
        }

        .dark-mode .card-header h2 {
            color: var(--text-dark);
        }

        .card-header p {
            color: var(--text-light);
            font-size: 0.95rem;
        }

        .dark-mode .card-header p {
            color: var(--text-light-dark);
        }

        .form-group {
            margin-bottom: 20px;
        }

        .form-label {
            display: block;
            margin-bottom: 8px;
            font-weight: 600;
            color: var(--text);
            font-size: 0.95rem;
            display: flex;
            align-items: center;
            gap: 8px;
        }

        .dark-mode .form-label {
            color: var(--text-dark);
        }

        .form-control {
            width: 100%;
            padding: 16px 18px;
            border: 2px solid var(--gray);
            border-radius: 12px;
            font-size: 1rem;
            transition: var(--transition);
            background-color: white;
            color: var(--text);
            font-weight: 500;
        }

        .dark-mode .form-control {
            background-color: var(--bg-dark);
            border-color: var(--gray-dark);
            color: var(--text-dark);
        }

        .form-control:focus {
            outline: none;
            border-color: var(--primary);
            box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
        }

        .form-control::placeholder {
            color: var(--text-light);
            font-weight: 400;
        }

        .dark-mode .form-control::placeholder {
            color: var(--text-light-dark);
        }

        .crypto-options {
            display: flex;
            gap: 12px;
            margin-bottom: 24px;
        }

        .crypto-option {
            flex: 1;
            text-align: center;
            padding: 20px 12px;
            border: 2px solid var(--gray);
            border-radius: 12px;
            cursor: pointer;
            transition: var(--transition);
            background: white;
            position: relative;
            overflow: hidden;
        }

        .dark-mode .crypto-option {
            background: var(--bg-dark);
            border-color: var(--gray-dark);
        }

        .crypto-option:hover {
            border-color: var(--primary-light);
            transform: translateY(-3px);
            box-shadow: var(--shadow);
        }

        .crypto-option.selected {
            border-color: var(--primary);
            background: linear-gradient(135deg, rgba(99, 102, 241, 0.05), rgba(79, 70, 229, 0.1));
            position: relative;
        }

        .dark-mode .crypto-option.selected {
            background: linear-gradient(135deg, rgba(99, 102, 241, 0.15), rgba(79, 70, 229, 0.2));
        }

        .crypto-option.selected::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            height: 3px;
            background: linear-gradient(90deg, var(--primary), var(--primary-dark));
        }

        .crypto-option.selected::after {
            content: "✓";
            position: absolute;
            top: 8px;
            right: 8px;
            background: var(--primary);
            color: white;
            width: 20px;
            height: 20px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 12px;
            font-weight: bold;
        }

        .crypto-icon {
            width: 48px;
            height: 48px;
            border-radius: 12px;
            background: linear-gradient(135deg, var(--primary-light), var(--primary));
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 12px;
            color: white;
            font-size: 1.25rem;
            box-shadow: var(--shadow);
        }

        .crypto-name {
            font-weight: 700;
            margin-bottom: 6px;
            color: var(--text);
            font-size: 1.1rem;
        }

        .dark-mode .crypto-name {
            color: var(--text-dark);
        }

        .crypto-price {
            font-size: 0.875rem;
            color: var(--text-light);
            margin-bottom: 4px;
            font-weight: 500;
        }

        .dark-mode .crypto-price {
            color: var(--text-light-dark);
        }

        .price-change {
            font-size: 0.75rem;
            font-weight: 600;
            padding: 2px 6px;
            border-radius: 4px;
            display: inline-block;
        }

        .price-change.positive {
            background: rgba(16, 185, 129, 0.1);
            color: var(--success);
        }

        .price-change.negative {
            background: rgba(239, 68, 68, 0.1);
            color: var(--danger);
        }

        .btn {
            display: block;
            width: 100%;
            padding: 18px;
            background: linear-gradient(135deg, var(--primary), var(--primary-dark));
            color: white;
            border: none;
            border-radius: 12px;
            font-size: 1.1rem;
            font-weight: 600;
            cursor: pointer;
            transition: var(--transition);
            text-align: center;
            box-shadow: var(--shadow);
            position: relative;
            overflow: hidden;
        }

        .btn::before {
            content: '';
            position: absolute;
            top: 0;
            left: -100%;
            width: 100%;
            height: 100%;
            background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
            transition: left 0.5s;
        }

        .btn:hover {
            transform: translateY(-3px);
            box-shadow: var(--shadow-lg);
        }

        .btn:hover::before {
            left: 100%;
        }

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

        .btn i {
            margin-right: 8px;
        }

        .btn:disabled {
            background: var(--gray);
            cursor: not-allowed;
            transform: none;
            box-shadow: none;
        }

        .btn:disabled::before {
            display: none;
        }

        .dark-mode .btn:disabled {
            background: var(--gray-dark);
        }

        .btn-secondary {
            background: linear-gradient(135deg, var(--success), var(--secondary-dark));
            box-shadow: 0 4px 12px rgba(16, 185, 129, 0.3);
        }

        .btn-secondary:hover {
            box-shadow: 0 6px 16px rgba(16, 185, 129, 0.4);
        }

        .timer {
            text-align: center;
            padding: 24px;
            background: linear-gradient(135deg, #fffbeb, #fef3c7);
            border-radius: var(--radius);
            margin: 24px 0;
            border: 2px dashed #f59e0b;
            position: relative;
            overflow: hidden;
        }

        .dark-mode .timer {
            background: linear-gradient(135deg, #451a03, #7c2d12);
            border-color: #f59e0b;
        }

        .timer::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            height: 4px;
            background: linear-gradient(90deg, #f59e0b, #fbbf24, #f59e0b);
            animation: progress 10s linear infinite;
        }

        @keyframes progress {
            0% { transform: translateX(-100%); }
            100% { transform: translateX(100%); }
        }

        .timer-title {
            font-size: 1rem;
            color: #d97706;
            margin-bottom: 8px;
            font-weight: 600;
        }

        .timer-display {
            font-size: 2.5rem;
            font-weight: 700;
            color: #d97706;
            font-family: 'Courier New', monospace;
            letter-spacing: 2px;
        }

        .payment-info {
            background: var(--light);
            border-radius: var(--radius);
            padding: 24px;
            margin-top: 24px;
            border: 1px solid var(--gray);
        }

        .dark-mode .payment-info {
            background: var(--bg-dark);
            border-color: var(--gray-dark);
        }

        .payment-info h3 {
            margin-bottom: 20px;
            color: var(--dark);
            font-size: 1.2rem;
            display: flex;
            align-items: center;
            gap: 10px;
        }

        .dark-mode .payment-info h3 {
            color: var(--text-dark);
        }

        .payment-info h3 i {
            color: var(--primary);
        }

        .payment-detail {
            display: flex;
            justify-content: space-between;
            margin-bottom: 16px;
            padding-bottom: 16px;
            border-bottom: 1px solid var(--gray);
        }

        .dark-mode .payment-detail {
            border-bottom: 1px solid var(--gray-dark);
        }

        .payment-detail:last-child {
            border-bottom: none;
            margin-bottom: 0;
        }

        .payment-label {
            font-weight: 600;
            color: var(--text);
            display: flex;
            align-items: center;
            gap: 8px;
        }

        .dark-mode .payment-label {
            color: var(--text-dark);
        }

        .payment-value {
            color: var(--text);
            font-weight: 600;
        }

        .dark-mode .payment-value {
            color: var(--text-dark);
        }

        .iban-box {
            background: white;
            border: 2px dashed var(--primary);
            border-radius: 12px;
            padding: 20px;
            text-align: center;
            margin: 20px 0;
            cursor: pointer;
            transition: var(--transition);
            position: relative;
            overflow: hidden;
        }

        .dark-mode .iban-box {
            background: var(--bg-dark);
        }

        .iban-box:hover {
            background: rgba(99, 102, 241, 0.05);
            transform: translateY(-2px);
            box-shadow: var(--shadow);
        }

        .dark-mode .iban-box:hover {
            background: rgba(99, 102, 241, 0.1);
        }

        .iban-label {
            font-size: 0.9rem;
            color: var(--text-light);
            margin-bottom: 8px;
            font-weight: 500;
        }

        .dark-mode .iban-label {
            color: var(--text-light-dark);
        }

        .iban-value {
            font-size: 1.1rem;
            font-weight: 700;
            color: var(--primary);
            font-family: 'Courier New', monospace;
            letter-spacing: 1px;
            padding: 8px 12px;
            background: rgba(99, 102, 241, 0.05);
            border-radius: 8px;
            display: inline-block;
        }

        .dark-mode .iban-value {
            background: rgba(99, 102, 241, 0.1);
        }

        .copy-notification {
            position: absolute;
            top: -40px;
            left: 50%;
            transform: translateX(-50%);
            background: var(--success);
            color: white;
            padding: 8px 16px;
            border-radius: 20px;
            font-size: 0.9rem;
            font-weight: 500;
            opacity: 0;
            transition: opacity 0.3s ease;
            box-shadow: var(--shadow);
        }

        .copy-notification.show {
            opacity: 1;
        }

        .note {
            background: rgba(16, 185, 129, 0.1);
            border-left: 4px solid var(--success);
            padding: 16px;
            border-radius: 8px;
            margin-top: 20px;
            font-size: 0.9rem;
            color: #065f46;
            display: flex;
            align-items: flex-start;
            gap: 10px;
        }

        .dark-mode .note {
            background: rgba(16, 185, 129, 0.15);
            color: #a7f3d0;
        }

        .warning {
            background: rgba(245, 158, 11, 0.1);
            border-left: 4px solid var(--warning);
            padding: 16px;
            border-radius: 8px;
            margin-top: 20px;
            font-size: 0.9rem;
            color: #92400e;
            display: flex;
            align-items: flex-start;
            gap: 10px;
        }

        .dark-mode .warning {
            background: rgba(245, 158, 11, 0.15);
            color: #fcd34d;
        }

        .hidden {
            display: none;
        }

        .fade-in {
            animation: fadeIn 0.5s ease;
        }

        @keyframes fadeIn {
            from { opacity: 0; transform: translateY(10px); }
            to { opacity: 1; transform: translateY(0); }
        }

        .loading {
            text-align: center;
            padding: 40px 20px;
            color: var(--text-light);
        }

        .dark-mode .loading {
            color: var(--text-light-dark);
        }

        .loading i {
            font-size: 2.5rem;
            margin-bottom: 16px;
            color: var(--primary);
        }

        .loading p {
            font-size: 1rem;
            font-weight: 500;
        }

        .success-animation {
            text-align: center;
            margin: 30px 0;
        }

        .success-animation i {
            font-size: 5rem;
            color: var(--success);
            animation: pulse 1.5s infinite;
        }

        @keyframes pulse {
            0% { transform: scale(1); }
            50% { transform: scale(1.1); }
            100% { transform: scale(1); }
        }

        .transaction-details {
            background: var(--light);
            border-radius: var(--radius);
            padding: 24px;
            margin: 20px 0;
            text-align: center;
            border: 1px solid var(--gray);
        }

        .dark-mode .transaction-details {
            background: var(--bg-dark);
            border-color: var(--gray-dark);
        }

        .transaction-id, .estimated-time {
            margin-bottom: 12px;
            font-weight: 600;
            color: var(--text);
            display: flex;
            justify-content: center;
            align-items: center;
            gap: 8px;
        }

        .dark-mode .transaction-id, .dark-mode .estimated-time {
            color: var(--text-dark);
        }

        .payment-actions {
            display: flex;
            gap: 12px;
            margin-top: 20px;
        }

        .payment-actions .btn {
            flex: 1;
        }

        footer {
            text-align: center;
            margin-top: 40px;
            color: var(--text-light);
            font-size: 0.9rem;
            padding: 20px 0;
        }

        .dark-mode footer {
            color: var(--text-light-dark);
        }

        footer a {
            color: var(--primary);
            text-decoration: none;
            font-weight: 500;
            transition: var(--transition);
        }

        footer a:hover {
            text-decoration: underline;
        }

        .error-message {
            color: var(--danger);
            font-size: 0.85rem;
            margin-top: 6px;
            display: none;
            font-weight: 500;
        }

        .form-control.error {
            border-color: var(--danger);
            box-shadow: 0 0 0 3px rgba(239, 68, 68, 0.1);
        }

        .form-control.success {
            border-color: var(--success);
            box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.1);
        }

        .amount-preview {
            background: var(--light);
            border-radius: 10px;
            padding: 16px;
            margin-top: 16px;
            text-align: center;
            border: 1px solid var(--gray);
        }

        .dark-mode .amount-preview {
            background: var(--bg-dark);
            border-color: var(--gray-dark);
        }

        .amount-preview-label {
            font-size: 0.875rem;
            color: var(--text-light);
            margin-bottom: 6px;
        }

        .dark-mode .amount-preview-label {
            color: var(--text-light-dark);
        }

        .amount-preview-value {
            font-size: 1.25rem;
            font-weight: 700;
            color: var(--primary);
        }

        .telegram-notification {
            background: rgba(0, 136, 204, 0.1);
            border-left: 4px solid #0088cc;
            padding: 16px;
            border-radius: 8px;
            margin-top: 20px;
            font-size: 0.9rem;
            color: #006699;
            display: flex;
            align-items: center;
            gap: 10px;
        }

        .dark-mode .telegram-notification {
            background: rgba(0, 136, 204, 0.15);
            color: #66c2ff;
        }

        @media (max-width: 480px) {
            .container {
                padding: 0 10px;
            }
            
            .card {
                padding: 20px;
            }
            
            .crypto-options {
                flex-direction: column;
            }
            
            .payment-actions {
                flex-direction: column;
            }
        }