:root {
    --background-color: #08041b;
    --container-color: #211e33;
    --text-color: #FFFFFF;
    --error-color: #FF0000;
    --button-gradient-left: #FF6200;
    --button-gradient-right: #FF0000;
    --select-all-bg: #e9e8ed;
    --select-all-text: #000000;
    --border-radius: 10px;
    --transition-speed: 0.3s;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    color: var(--text-color);
    background-color: var(--background-color);
    margin: 0;
    padding: 0;
}

.gradient-header {
    background: transparent;
}

header h1 {
    margin: 0;
    font-weight: 600;
    font-size: 2rem;
    color: var(--text-color);
}

/* Container Styling */
main.container {
    background-color: var(--container-color);
    border-radius: var(--border-radius);
    padding: 2rem;
    max-width: 700px;
    margin: 0 auto;
}

/* Form styles */
form {
    border: none;
    border-radius: var(--border-radius);
    box-shadow: none;
    background-color: transparent;
    padding: 0;
}

.form-control, .form-select {
    border-radius: var(--border-radius);
    border: 1px solid #FFFFFF;
    background-color: #FFFFFF;
    color: #333;
    padding: 0.75rem;
    transition: all var(--transition-speed) ease;
}

.form-control:focus, .form-select:focus {
    border-color: #FFFFFF;
    box-shadow: none;
}

.form-control.is-invalid, .form-select.is-invalid {
    border-color: var(--error-color);
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' fill='none' stroke='%23FF0000' viewBox='0 0 12 12'%3E%3Ccircle cx='6' cy='6' r='4.5'/%3E%3Cpath stroke-linejoin='round' d='M5.8 3.6h.4L6 6.5z'/%3E%3Ccircle cx='6' cy='8.2' r='.6' fill='%23FF0000' stroke='none'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right calc(0.375em + 0.1875rem) center;
    background-size: calc(0.75em + 0.375rem) calc(0.75em + 0.375rem);
}

.form-control::placeholder, .form-select option[disabled] {
    color: #999;
}

.form-label {
    font-weight: 500;
    margin-bottom: 0.5rem;
    color: var(--text-color);
}

.invalid-feedback {
    color: var(--error-color);
}

/* Checkbox Group */
.checkbox-group {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 10px;
}

.checkbox-group label {
    display: flex;
    align-items: center;
    gap: 5px;
    color: var(--text-color);
}

.checkbox-group input[type="checkbox"] {
    margin: 0;
    vertical-align: middle;
    background-color: #FFFFFF;
    border: 1px solid #FFFFFF;
}

.checkbox-group input[type="checkbox"]:checked {
    background-color: var(--button-gradient-left);
    border-color: var(--button-gradient-left);
}

/* Select All Button */
.btn-secondary {
    background-color: var(--select-all-bg);
    color: var(--select-all-text);
    border: none;
    border-radius: var(--border-radius);
    transition: background-color var(--transition-speed) ease;
}

.btn-secondary:hover {
    background-color: #d0d0d5;
}

/* Button Styling */
.gradient-button {
    background: linear-gradient(90deg, var(--button-gradient-left), var(--button-gradient-right));
    border: none;
    border-radius: var(--border-radius);
    padding: 1rem 2rem;
    font-weight: 600;
    color: var(--text-color);
    transition: transform var(--transition-speed) ease;
}

.gradient-button:hover {
    transform: translateY(-2px);
    background: linear-gradient(90deg, var(--button-gradient-right), var(--button-gradient-left));
}

.gradient-button:active {
    transform: translateY(0);
}

/* Response Items */
.response-item {
    background-color: var(--container-color);
    padding: 15px;
    border-radius: var(--border-radius);
    border: 1px solid rgba(255, 255, 255, 0.1);
    margin-bottom: 15px;
}

.response-item h3 {
    color: var(--text-color);
    font-size: 20px;
    margin-bottom: 10px;
}

.response-item p {
    color: var(--text-color);
    font-size: 16px;
    margin: 0;
}

/* Loader */
.loader {
    border: 4px solid rgba(255, 255, 255, 0.2);
    border-top: 4px solid var(--button-gradient-left);
    border-radius: 50%;
    width: 30px;
    height: 30px;
    animation: spin 1s linear infinite;
    display: inline-block;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Responsive Adjustments */
@media (max-width: 768px) {
    header h1 {
        font-size: 1.5rem;
    }

    .gradient-button {
        padding: 0.75rem 1.5rem;
    }

    main.container {
        max-width: 100%;
        padding: 1.5rem;
    }

    .checkbox-group {
        grid-template-columns: 1fr;
    }

    .response-item h3 {
        font-size: 18px;
    }

    .response-item p {
        font-size: 14px;
    }
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--background-color);
}

::-webkit-scrollbar-thumb {
    background: #FFFFFF;
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: #CCCCCC;
}