/* --- GLOBAL STYLES & VARIABLES --- */
        :root {
            --primary-brand-color: #2196F3; /* Modern Blue */
            --primary-brand-dark: #1976D2;
            --primary-brand-light: #64B5F6;

            --secondary-accent-color: #4CAF50; /* Green for success/action */
            --secondary-accent-dark: #388E3C;

            --background-page: #e9eef2; /* Light bluish-grey for body */
            --background-card: #ffffff;
            --background-input: #f8fbfd; /* Very light blue-grey for input fields */

            --text-dark: #2c3e50; /* Rich charcoal blue */
            --text-medium: #5a708a; /* Softer grey-blue for labels */
            --text-light: #9ab7cc; /* For placeholders */

            --border-color-default: #dce4eb;
            --border-color-focus: var(--primary-brand-color);

            --error-color: #ef5350; /* Soft red */
            --error-bg: #ffebee;

            --shadow-subtle: 0 5px 25px rgba(0, 0, 0, 0.08);
            --shadow-hover: 0 8px 30px rgba(0, 0, 0, 0.12);
            --shadow-input-focus: 0 0 0 0.2rem rgba(33, 150, 243, 0.25);

            --border-radius-card: 20px;
            --border-radius-input: 12px;
            --button-height: 58px;
            --input-height: 58px;
        }

        body {
            font-family: 'Roboto', sans-serif;
            background-color: var(--background-page);
            display: flex;
            justify-content: center;
            align-items: center;
            min-height: 100vh;
            margin: 0;
            overflow-x: hidden;
            line-height: 1.6;
            color: var(--text-dark);
            font-size: 16px;
        }

        /* --- REGISTER CONTAINER --- */
        .register-container {
            background: var(--background-card);
            padding: 45px 40px;
            border-radius: var(--border-radius-card);
            box-shadow: var(--shadow-subtle);
            width: 90%;
            max-width: 500px;
            text-align: center;
            animation: fadeIn 0.8s ease-out;
            border: 1px solid var(--border-color-default); /* Subtle border */
        }

        @keyframes fadeIn {
            from { opacity: 0; transform: translateY(30px); }
            to { opacity: 1; transform: translateY(0); }
        }

        /* --- HEADER LOGO (CHANTIER) --- */
        .header-logo {
            font-family: 'Montserrat', sans-serif;
            font-size: 3.5rem;
            font-weight: 800; /* Bolder */
            margin-bottom: 40px;
            letter-spacing: 4px;
            text-transform: uppercase;
            background: linear-gradient(90deg, var(--primary-brand-color), var(--primary-brand-light), var(--primary-brand-color));
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            text-shadow: 2px 2px 8px rgba(0,0,0,0.1);
            position: relative; /* For the subtle underline */
        }
        .header-logo::after {
            content: '';
            position: absolute;
            bottom: -15px;
            left: 50%;
            transform: translateX(-50%);
            width: 80px;
            height: 4px;
            background-color: var(--secondary-accent-color);
            border-radius: 2px;
        }

        /* --- INPUT GROUPS & FIELDS --- */
        .input-group {
            margin-bottom: 25px; /* More spacing */
            position: relative;
        }

        .input-group-prepend-icon {
            position: absolute;
            left: 20px;
            top: 50%;
            transform: translateY(-50%);
            z-index: 2;
            color: var(--text-medium);
            font-size: 1.25rem; /* Larger icon */
            transition: color 0.3s ease;
        }

        .form-control, .form-select {
            background-color: var(--background-input);
            border: 1px solid var(--border-color-default);
            border-radius: var(--border-radius-input);
            font-size: 1.05rem;
            padding: 16px 20px;
            padding-left: 60px; /* Space for icon */
            color: var(--text-dark);
            height: var(--input-height);
            transition: all 0.3s ease;
            box-shadow: inset 0 1px 3px rgba(0,0,0,0.05); /* Inner shadow for depth */
        }

        .form-control::placeholder {
            color: var(--text-light);
            opacity: 1;
        }

        .form-control:focus, .form-select:focus {
            border-color: var(--border-color-focus);
            box-shadow: var(--shadow-input-focus);
            background-color: var(--background-card);
            outline: none;
        }

        .input-group:focus-within .input-group-prepend-icon {
            color: var(--primary-brand-color);
        }

        /* --- PHONE CODE SELECT STYLES --- */
        .input-group-text-custom {
            background-color: var(--background-input);
            border: 1px solid var(--border-color-default);
            border-right: none;
            border-top-left-radius: var(--border-radius-input);
            border-bottom-left-radius: var(--border-radius-input);
            color: var(--text-dark);
            padding: 0 18px;
            display: flex;
            align-items: center;
            height: var(--input-height);
            margin-right: -1px;
            transition: all 0.3s ease;
            font-size: 1.05rem;
        }
        .input-group-text-custom i {
            margin-right: 12px;
            color: var(--text-medium);
            font-size: 1.25rem;
        }
        .input-group-text-custom select {
            background: none;
            border: none;
            color: var(--text-dark);
            padding: 0;
            height: auto;
            appearance: none;
            -webkit-appearance: none;
            -moz-appearance: none;
            cursor: pointer;
            font-size: 1.05rem;
            max-width: 100px; /* Restrict width */
        }
        .input-group-text-custom select:focus {
            outline: none;
            box-shadow: none;
        }
        .input-group-text-custom:focus-within {
            border-color: var(--primary-brand-color);
            box-shadow: var(--shadow-input-focus);
            background-color: var(--background-card);
        }

        /* --- BUTTONS --- */
        .btn {
            font-weight: 600;
            font-size: 1.2rem; /* Slightly larger */
            padding: 17px 0;
            border-radius: var(--border-radius-input);
            transition: all 0.3s ease;
            width: 100%;
            letter-spacing: 0.8px; /* More spacing */
            text-transform: uppercase;
        }

        .btn-register {
            background: linear-gradient(45deg, var(--secondary-accent-color), var(--secondary-accent-dark));
            border: none;
            color: white;
            margin-top: 35px;
            box-shadow: 0 6px 20px rgba(76, 175, 80, 0.3);
        }
        .btn-register:hover {
            background: linear-gradient(45deg, var(--secondary-accent-dark), var(--secondary-accent-color));
            transform: translateY(-5px);
            box-shadow: 0 10px 25px rgba(76, 175, 80, 0.4);
        }
        .btn-register:active {
            transform: translateY(0);
            box-shadow: 0 4px 15px rgba(76, 175, 80, 0.2);
        }

        .btn-download-app {
            background-color: transparent;
            color: var(--primary-brand-color);
            border: 2px solid var(--primary-brand-color);
            margin-top: 18px; /* More space */
            box-shadow: none; /* No initial shadow */
        }
        .btn-download-app:hover {
            background-color: var(--primary-brand-color);
            color: white;
            transform: translateY(-5px);
            box-shadow: 0 6px 15px rgba(33, 150, 243, 0.25);
        }
        .btn-download-app:active {
            transform: translateY(0);
            box-shadow: 0 2px 10px rgba(33, 150, 243, 0.15);
        }

        /* --- LOGIN LINK --- */
        .login-link {
            margin-top: 40px; /* Increased space */
            font-size: 1.05rem;
            color: var(--text-dark);
        }
        .login-link a {
            color: var(--primary-brand-color); /* Consistent branding */
            text-decoration: none;
            font-weight: 700; /* Bolder */
            transition: color 0.3s ease, text-decoration 0.3s ease;
        }
        .login-link a:hover {
            color: var(--primary-brand-dark);
            text-decoration: underline;
        }

        /* --- ERROR MESSAGE --- */
        .error-message {
            color: var(--error-color);
            font-size: 0.98rem;
            margin-bottom: 28px;
            text-align: center;
            padding: 14px;
            background-color: var(--error-bg);
            border-left: 6px solid var(--error-color);
            border-radius: var(--border-radius-md);
            animation: slideInDown 0.4s ease-out;
            font-weight: 500;
            display: flex;
            align-items: center;
            gap: 10px;
            justify-content: center;
        }
        .error-message i {
            font-size: 1.2em;
        }

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

        /* --- CAPTCHA SPECIFIC STYLES --- */
        .verification-code-input {
            display: flex;
            align-items: center;
            justify-content: space-between;
        }
        .verification-code-input .form-control {
            flex-grow: 1;
            margin-right: 15px;
            padding-left: 60px; /* Keep space for icon */
        }
        .verification-code-image {
            height: var(--input-height);
            width: 130px; /* Slightly wider for better readability */
            object-fit: cover;
            cursor: pointer;
            border-radius: var(--border-radius-input);
            border: 1px solid var(--border-color-default);
            padding: 8px; /* Inner padding for the image */
            vertical-align: middle;
            background-color: var(--background-input);
            transition: all 0.3s ease;
            box-shadow: inset 0 1px 3px rgba(0,0,0,0.05);
        }
        .verification-code-image:hover {
            box-shadow: 0 0 0 0.2rem rgba(33, 150, 243, 0.25);
            border-color: var(--primary-brand-color);
        }


        /* --- RESPONSIVE ADJUSTMENTS --- */
        @media (max-width: 576px) {
            .register-container {
                padding: 30px 25px;
                border-radius: 15px;
                max-width: 95%;
            }
            .header-logo {
                font-size: 2.8rem;
                margin-bottom: 30px;
            }
            .header-logo::after {
                bottom: -10px;
                width: 60px;
            }
            .form-control, .form-select, .btn {
                font-size: 0.95rem;
                padding: 14px 18px;
                height: 50px;
                padding-left: 50px;
            }
            .input-group-prepend-icon {
                left: 15px;
                font-size: 1.15rem;
            }
            .input-group-text-custom {
                height: 50px;
                padding: 0 15px;
            }
            .input-group-text-custom i {
                margin-right: 8px;
                font-size: 1.15rem;
            }
            .verification-code-image {
                height: 50px;
                width: 110px;
            }
            .btn-register, .btn-download-app {
                padding: 15px 0;
            }
            .login-link {
                margin-top: 30px;
                font-size: 0.95rem;
            }
            .error-message {
                font-size: 0.9rem;
                padding: 10px;
            }
        }