:root {
    --primary-color: #0a0a0a;
    --secondary-color: #1a1a1a;
    --font-color: #e0e0e0;
    --accent-color: #007bff;
    --border-color: #333;
    --error-color: #e53935;
    --success-color: #43a047;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--primary-color);
    color: var(--font-color);
    line-height: 1.6;
    margin: 0;
    padding: 20px;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    background-color: var(--secondary-color);
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
}

header {
    text-align: center;
    margin-bottom: 30px;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 20px;
}

.logo {
    max-width: 150px;
    margin-bottom: 15px;
}

h1 {
    color: var(--font-color);
    font-size: 2.5em;
    margin-bottom: 10px;
}

header p {
    font-size: 1.1em;
    color: #aaa;
}

fieldset {
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 20px;
    margin-bottom: 25px;
}

legend {
    padding: 0 10px;
    font-size: 1.4em;
    font-weight: bold;
    color: var(--accent-color);
}

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

label {
    display: block;
    font-weight: bold;
    margin-bottom: 8px;
    font-size: 1.1em;
}

input[type="text"],
input[type="email"],
input[type="tel"] {
    width: 100%;
    padding: 12px;
    background-color: var(--primary-color);
    border: 1px solid var(--border-color);
    border-radius: 5px;
    color: var(--font-color);
    font-size: 1em;
    box-sizing: border-box;
}

input[type="text"]:focus,
input[type="email"]:focus,
input[type="tel"]:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 5px rgba(0, 123, 255, 0.5);
}

.radio-group label {
    display: block;
    margin-bottom: 10px;
    font-weight: normal;
    background-color: var(--primary-color);
    padding: 10px;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.2s ease-in-out;
}

.radio-group label:hover {
    background-color: #2a2a2a;
}

input[type="radio"] {
    margin-right: 10px;
}

button[type="submit"] {
    display: block;
    width: 100%;
    padding: 15px;
    background-color: var(--accent-color);
    color: #fff;
    border: none;
    border-radius: 5px;
    font-size: 1.2em;
    font-weight: bold;
    cursor: pointer;
    transition: background-color 0.3s;
}

button[type="submit"]:hover {
    background-color: #0056b3;
}

#form-status {
    text-align: center;
    margin-top: 20px;
    font-size: 1.1em;
}

.hidden {
    display: none;
}

#loading-spinner {
    border: 4px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top: 4px solid var(--accent-color);
    width: 40px;
    height: 40px;
    animation: spin 1s linear infinite;
    margin: 20px auto;
}

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

/* Responsive Design */
@media (max-width: 600px) {
    body {
        padding: 10px;
    }
    .container {
        padding: 20px;
    }
    h1 {
        font-size: 2em;
    }
    legend {
        font-size: 1.2em;
    }
}