@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap');

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

        :root {
            --primary-color: #4a90e2;
            --secondary-color: #357abd;
            --accent-color: #5ba3f5;
            --text-dark: #1f2937;
            --text-light: #6b7280;
            --surface-light: rgba(255, 255, 255, 0.95);
            --surface-glass: rgba(255, 255, 255, 0.1);
            --error-color: #dc3545;
            --success-color: #28a745;
            --warning-color: #ffc107;
        }

        body {
            font-family: 'Inter', sans-serif;
            background: linear-gradient(to bottom, 
                #4a90e2 0%, 
                #357abd 40%, 
                #2c7cc4 65%, 
                #ffffff 65%, 
                #f8fafc 100%);
            background-repeat: no-repeat;
            background-size: 100% 100vh;
            min-height: 100vh;
            color: var(--text-dark);
            overflow-x: hidden;
        }

        @supports (-webkit-touch-callout: none) {
            body {
                background-attachment: scroll;
                position: relative;
            }
            
            body::before {
                content: '';
                position: fixed;
                top: 0;
                left: 0;
                width: 100%;
                height: 100vh;
                background: linear-gradient(to bottom, 
                    #4a90e2 0%, 
                    #357abd 40%, 
                    #2c7cc4 65%, 
                    #ffffff 65%, 
                    #f8fafc 100%);
                z-index: -1;
                pointer-events: none;
            }
        }

        @supports not (-webkit-touch-callout: none) {
            body {
                background-attachment: fixed;
            }
        }

        .container {
            max-width: 850px;
            margin: 0 auto;
            padding: 60px 20px;
            position: relative;
            z-index: 2;
        }

        .header {
            text-align: center;
            margin-bottom: 50px;
        }

        .header h1 {
            font-size: 2.8rem;
            font-weight: 700;
            margin-bottom: 12px;
            color: white;
        }

        .header p {
            font-size: 1.3rem;
            color: rgba(255, 255, 255, 0.9);
        }

        .form-container {
            background: var(--surface-light);
            backdrop-filter: blur(20px) saturate(180%);
            border-radius: 24px;
            padding: 60px 70px;
            border: 1px solid rgba(255, 255, 255, 0.2);
            box-shadow: 
                0 20px 40px rgba(0, 0, 0, 0.1),
                0 1px 2px rgba(0, 0, 0, 0.05),
                inset 0 1px 0 rgba(255, 255, 255, 0.2);
            animation: slideInUp 0.8s ease-out;
        }

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

        .form-title {
            color: #4a90e2;
            font-size: 2rem;
            margin-bottom: 35px;
            font-weight: 600;
            text-align: center;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 12px;
        }

        .form-row {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 24px;
        }

        .form-group {
            margin-bottom: 28px;
        }

        .form-row .form-group {
            margin-bottom: 0;
        }

        label {
            display: block;
            margin-bottom: 10px;
            font-weight: 500;
            color: var(--text-dark);
            font-size: 15px;
        }

        .required {
            color: var(--error-color);
            font-weight: 600;
        }

        input[type="text"],
        input[type="email"],
        input[type="tel"],
        input[type="password"] {
            width: 100%;
            padding: 18px 24px;
            border: 2px solid rgba(74, 144, 226, 0.2);
            border-radius: 12px;
            font-size: 17px;
            font-family: 'Inter', sans-serif;
            transition: all 0.3s ease;
            background: rgba(255, 255, 255, 0.8);
        }

        input:focus {
            outline: none;
            border-color: #4a90e2;
            background: rgba(255, 255, 255, 0.95);
            box-shadow: 0 0 0 3px rgba(74, 144, 226, 0.1);
            transform: translateY(-2px);
        }

        /* Validation visuelle uniquement après interaction */
        input.touched:invalid {
            border-color: var(--error-color);
        }

        .checkbox-group {
            margin-bottom: 24px;
            padding: 18px 20px;
            background: rgba(74, 144, 226, 0.05);
            border-radius: 12px;
        }

        .checkbox-label {
            display: flex;
            align-items: flex-start;
            cursor: pointer;
            font-size: 15px;
            line-height: 1.6;
        }

        .checkbox-label input[type="checkbox"] {
            margin-right: 12px;
            margin-top: 3px;
            width: 20px;
            height: 20px;
            cursor: pointer;
        }

        .checkbox-label a {
            color: #4a90e2;
            text-decoration: none;
            font-weight: 500;
        }

        .checkbox-label a:hover {
            text-decoration: underline;
        }

        .password-strength {
            margin-top: 10px;
            font-size: 14px;
            font-weight: 500;
            height: 20px;
        }

        .strength-weak {
            color: var(--error-color);
        }

        .strength-medium {
            color: var(--warning-color);
        }

        .strength-strong {
            color: var(--success-color);
        }

        .btn {
            width: 100%;
            padding: 20px;
            background: linear-gradient(135deg, #4a90e2 0%, #357abd 100%);
            color: white;
            border: none;
            border-radius: 12px;
            font-size: 17px;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s ease;
            font-family: 'Inter', sans-serif;
        }

        .btn:hover {
            transform: translateY(-2px);
            box-shadow: 0 10px 25px rgba(74, 144, 226, 0.3);
        }

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

        .loading {
            display: none;
        }

        .links {
            text-align: center;
            margin-top: 35px;
            padding-top: 35px;
            border-top: 1px solid rgba(74, 144, 226, 0.1);
        }

        .links p {
            margin-bottom: 12px;
            color: var(--text-light);
            font-size: 15px;
        }

        .links a {
            color: #4a90e2;
            text-decoration: none;
            font-weight: 500;
            font-size: 15px;
            transition: all 0.2s ease;
        }

        .links a:hover {
            color: #357abd;
            text-decoration: underline;
        }

        .alert {
            padding: 18px 24px;
            border-radius: 12px;
            margin-bottom: 28px;
            font-weight: 500;
            font-size: 15px;
            animation: slideIn 0.3s ease;
        }

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

        .alert-error {
            background: rgba(239, 68, 68, 0.1);
            color: #dc2626;
            border: 1px solid rgba(239, 68, 68, 0.2);
        }

        .alert-success {
            background: rgba(34, 197, 94, 0.1);
            color: #16a34a;
            border: 1px solid rgba(34, 197, 94, 0.2);
        }

        @media (min-width: 1440px) {
            .container {
                max-width: 920px;
            }
        }

        @media (max-width: 1024px) {
            .container {
                max-width: 700px;
            }
            
            .form-container {
                padding: 50px;
            }
        }

        @media (max-width: 768px) {
            .container {
                max-width: 600px;
                padding: 40px 15px;
            }
            
            .header h1 {
                font-size: 2.2rem;
            }
            
            .header p {
                font-size: 1.1rem;
            }
            
            .form-container {
                padding: 35px 30px;
            }
            
            .form-row {
                grid-template-columns: 1fr;
                gap: 0;
            }
            
            .form-row .form-group {
                margin-bottom: 25px;
            }
            
            input[type="text"],
            input[type="email"],
            input[type="tel"],
            input[type="password"] {
                font-size: 16px;
                padding: 16px 20px;
            }
            
            .btn {
                font-size: 16px;
                padding: 18px;
            }
        }

        @media (max-width: 480px) {
            .container {
                padding: 30px 15px;
            }
            
            .header h1 {
                font-size: 2rem;
            }
            
            .form-container {
                padding: 25px 20px;
            }
        }