:root {
    --background-page: #f9f9fc;
    --text-color: #333;
    --border-color: #dcdde1;
    --primary-color: #4CAF50;
    --primary-color-hover: #45a049;
    --white-color: #ffffff;
    --error-color: #d9534f;
    --input-focus-color: #4CAF50;
}

body {
    font-family: Arial, sans-serif;
    background-color: var(--background-page);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
}

.container {
    width: 90%;
    max-width: 500px;
    background-color: var(--white-color);
    padding: 25px;
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.1);
    border-radius: 10px;
    text-align: left;
}

h1 {
    font-size: 24px;
    color: var(--text-color);
    margin-bottom: 20px;
    text-align: center;
}

.required-note {
    color: var(--error-color);
    font-size: 0.85em;
    text-align: center;
}

form {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.form-group {
    display: flex;
    flex-direction: column;
    width: 100%;
}

label {
    font-weight: bold;
    color: var(--text-color);
    margin-bottom: 5px;
}

input[type="text"],
input[type="password"],
input[type="email"] {
    width: 100%;
    padding: 10px;
    border: 1px solid var(--border-color);
    border-radius: 5px;
    margin-top: 5px;
    box-sizing: border-box;
    transition: all 0.3s ease;
}

input[type="text"]:focus,
input[type="password"]:focus,
input[type="email"]:focus {
    outline: none;
    border-color: var(--input-focus-color);
    box-shadow: 0 0 8px rgba(76, 175, 80, 0.2);
}

.error {
    color: var(--error-color);
    font-size: 0.85em;
    margin-top: 5px;
}

.button-group {
    display: flex;
    gap: 10px;
    margin-top: 20px;
    justify-content: center;
}

.submit-button,
.back-button {
    padding: 12px 20px;
    font-size: 16px;
    color: var(--white-color);
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s ease;
    text-decoration: none;
}

.submit-button {
    background-color: var(--primary-color);
}

.submit-button:hover {
    background-color: var(--primary-color-hover);
}

.back-button {
    background-color: #555;
}

.back-button:hover {
    background-color: #444;
}