/* 共通スタイル */
 * {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'Poppins', sans-serif;
}

body {
    background: linear-gradient(135deg, #87CEFA, #00AEEF);
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    padding: 20px;
}

.login-container {
    background: white;
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    width: 100%;
    max-width: 400px;
    text-align: center;
    animation: fadeIn 0.5s ease-in-out;
}

h2 {
    margin-bottom: 20px;
    color: #007ACC;
    font-weight: 600;
}

.input-group {
    width: 100%;
    margin-bottom: 15px;
    position: relative;
}

.input-group input {
    width: 100%;
    padding: 12px;
    border: 2px solid #ddd;
    border-radius: 8px;
    font-size: 16px;
    transition: all 0.3s ease-in-out;
}

.input-group input:focus {
    border-color: #00AEEF;
    box-shadow: 0 0 8px rgba(0, 174, 239, 0.5);
    outline: none;
}

.checkbox-group {
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 14px;
    margin-bottom: 15px;
}

.checkbox-group label {
    display: flex;
    align-items: center;
    cursor: pointer;
    color: #333;
}

button {
    width: 100%;
    padding: 12px;
    background: linear-gradient(90deg, #00AEEF, #007ACC);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    cursor: pointer;
    transition: all 0.3s ease-in-out;
}

button:hover {
    background: linear-gradient(90deg, #007ACC, #005F99);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0, 100, 180, 0.3);
}

.error-message {
    color: red;
    font-size: 14px;
    margin-bottom: 10px;
}

.register-link {
    display: block;
    margin-top: 10px;
    font-size: 14px;
    color: #007ACC;
    text-decoration: none;
}

.register-link:hover {
    text-decoration: underline;
}

/* フェードインアニメーション */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@media (max-width: 400px) {
    .login-container {
        padding: 20px;
    }

    .input-group input {
        font-size: 14px;
    }

    button {
        font-size: 14px;
    }
}