body {
        font-family: "Segoe UI", sans-serif;
        background: #f0f2f5;
        display: flex;
        justify-content: center;
        align-items: center;
        height: 100vh;
        margin: 0;
    }

    .login-box {
        background: #fff;
        padding: 40px;
        border-radius: 12px;
        box-shadow: 0 4px 20px rgba(0,0,0,0.1);
        width: 320px;
        text-align: center;
    }

    h2 {
        margin-bottom: 25px;
        color: #333;
    }

    input[type="text"],
    input[type="password"] {
        width: 100%;
        padding: 12px;
        margin: 10px 0;
        border: 1px solid #ccc;
        border-radius: 6px;
        font-size: 16px;
    }

    button {
        width: 100%;
        padding: 12px;
        background: #0078d4;
        border: none;
        color: #fff;
        font-size: 16px;
        border-radius: 6px;
        cursor: pointer;
        margin-top: 10px;
    }

    button:hover {
        background: #005fa3;
    }

    .footer {
        margin-top: 15px;
        font-size: 12px;
        color: #777;
    }

    /* ▼ スマホ専用調整 */
    @media (max-width: 480px) {
        .login-box {
            width: 90%; /* 画面幅に合わせて広がる */
        }
        .title {
            font-size: 22px;
        }
        input {
            font-size: 17px;
            padding: 14px 10px;
        }
        button {
            font-size: 17px;
            padding: 14px;
        }
    }