body {
    font-family: Arial, sans-serif;
    background: #f3f4f6;
    display: flex;
    justify-content: center;
    padding-top: 100px;
}

header {
    position: fixed;
    top: 20px;
    left: 20px;
}

.text-logo {
    text-decoration: none;
    color: #4f46e5;
    font-size: 22px;
    font-weight: bold;
}

.container {
    width: 100%;
    max-width: 550px;
    background: white;
    padding: 30px;
    border-radius: 16px;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.08);
}

h1 {
    text-align: center;
    color: #4f46e5;
    margin-bottom: 25px;
}

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

input,
textarea {
    padding: 14px;
    border: 2px solid #ddd;
    border-radius: 10px;
}

textarea {
    min-height: 150px;
    resize: vertical;
}

.btn {
    padding: 14px;
    background: #4f46e5;
    color: white;
    border: none;
    border-radius: 10px;
    cursor: pointer;
}

.mail-icon-area {
    text-align: center;
    margin-top: 30px;
}

.mail-icon {
    font-size: 42px;
    text-decoration: none;
}

.btn {
    font-size: 18px;
    font-weight: bold;
}

.btn:hover {
    opacity: 0.8;
}

/* メール問い合わせ設定 */
.mail-button {
    display: block;
    width: 100%;
    padding: 14px;
    margin-top: 15px;

    background: #4f46e5;
    color: white;
    text-decoration: none;
    text-align: center;

    border-radius: 10px;
    box-sizing: border-box;
    cursor: pointer;
}

.mail-button:hover {
    opacity: 0.8;
}

/* サンクスページ設定 */
.back-btn {
    display: block;
    width: 100%;
    padding: 14px;
    margin-top: 20px;

    background: #4f46e5;
    color: white;
    text-decoration: none;
    text-align: center;

    border-radius: 10px;
    box-sizing: border-box;

    font-size: 18px;
    font-weight: bold;
}

.back-btn:hover {
    opacity: 0.8;
}

.thanks-container {
    text-align: center;
}

input:focus,
textarea:focus {
    outline: 2px solid #4f46e5;
    border-color: #4f46e5;
}

/* ===== レスポンシブ対応 ===== */

/* タブレット（768px以下） */
@media (max-width: 768px) {
    body {
        padding-top: 70px;
    }

    .container {
        margin: 0 16px;
        padding: 24px;
    }
}

/* スマートフォン（480px以下） */
@media (max-width: 480px) {
    body {
        padding-top: 60px;
    }

    .container {
        margin: 0 12px;
        padding: 20px;
    }

    h1 {
        font-size: 22px;
    }

    input,
    textarea {
        padding: 12px;
        font-size: 16px;
        /* iOSの自動ズームを防ぐ */
    }

    .btn,
    .mail-button,
    .back-btn {
        font-size: 16px;
        padding: 12px;
    }
}