* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Hiragino Sans', 'Hiragino Kaku Gothic ProN', 'Noto Sans JP', sans-serif;
}

body {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background-color: #f5f5f5;
    padding: 20px;
}

a {
    text-decoration: none;
}

label {
    display: block;
    margin-bottom: 5px;
    color: #555;
    font-weight: bold;
}

input, select {
    width: 100%;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-size: 16px;
}

#registration-form{
    width: 520px;
}

.message{
    position: fixed;
    top: 0px;
    border-radius: 0 0 5px 5px;
    padding: 5px 20px;
    cursor: pointer;
}

.message.success{
    background-color: lightgreen;
    color: #333;
}

.message.error{
    background-color: hotpink;
    color: #FFF;
}

.message.hidden{
    display: none;
}

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

.radio-group {
    display: flex;
    gap: 20px;
}

.radio-option {
    display: flex;
    align-items: center;
}

.radio-option input {
    width: auto;
    margin-right: 8px;
}

.submit-container {
    margin-top: 30px;
}

.form-title {
    margin-bottom: 30px;
    padding-bottom: 10px;
    border-bottom: 1px solid #eee;
}

.back-link {
    display: block;
    margin-top: 15px;
    color: #666;
    text-align: center;
}

.back-link:hover {
    color: #4285F4;
}

.required:after {
    content: "*";
    color: #ff4d4d;
    margin-left: 3px;
}

.login-container {
    display: flex;
    width: 100%;
    max-width: 900px;
    background-color: white;
    border-radius: 20px;
    overflow: hidden;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
}

.image-column {
    flex: 1;
    background-color: #4285F4;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.image-column img {
    max-width: 100%;
    height: auto;
    border-radius: 10px;
}

.content-column {
    flex: 2;
    padding: 40px;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

h1 {
    margin-bottom: 20px;
    color: #333;
    font-size: 28px;
}

p {
    /*
    margin-bottom: 25px;
    */
    margin: 10px 0 0px;
    color: #555;
    line-height: 1.6;
}

.button-container {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.button {
    padding: 12px 20px;
    border-radius: 8px;
    font-weight: bold;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    border: none;
    font-size: 16px;
}

.login-button {
    background-color: #4285F4;
    color: white;
}

.login-button:hover {
    background-color: #3367d6;
}

.register-button {
    background-color: white;
    color: #4285F4;
    border: 2px solid #4285F4;
}

.register-button:hover {
    background-color: #f0f7ff;
}

/* タブレット対応 */
@media (max-width: 768px) {
    .login-container {
        flex-direction: column;
        max-width: 500px;
    }
    
    .image-column {
        min-height: 200px;
    }
    
    .content-column {
        padding: 30px;
    }
}

/* スマホ対応 */
@media (max-width: 480px) {
    .content-column {
        padding: 20px;
    }
    
    h1 {
        font-size: 24px;
    }
    
    .button {
        padding: 10px 15px;
    }
}