.auth-title {
    color: #1f2937;
    font-size: 30px;
    font-weight: 700;
    text-align: center;
    margin-bottom: 28px;
}
.auth-card {
    box-sizing: border-box;
    width: 100%;
    max-width: 620px;
    margin: 0 auto;
    padding: 40px;
    background: #fff;
    border: 1px solid #e5e7eb;
    border-radius: 20px;
    box-shadow: 0 18px 40px rgba(15, 23, 42, .08);
}
.auth-card .auth-control {
    box-sizing: border-box;
    width: 100%;
    max-width: none;
    min-width: 0;
    height: 56px;
    min-height: 56px;
    border-radius: 10px;
    font-family: "Noto Sans JP", sans-serif;
    font-size: 16px;
    line-height: 24px;
    padding: 0 8px;
}
.auth-card .auth-input,
.auth-card .register-input {
    padding: 0 18px;
    border: 2px solid #e5e7eb;
    background: #fff;
}
.auth-card .password-input-wrapper input { padding-right: 48px; }
.auth-card .auth-provider-buttons {
    display: grid;
    width: 100%;
    max-width: none;
    gap: 12px;
    margin: 0;
}
.auth-provider-buttons form { width: 100%; margin: 0; }
.auth-card .auth-social,
.auth-card .gsi-material-button-content-wrapper {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    text-decoration: none;
    font-weight: 500;
    letter-spacing: normal;
    white-space: nowrap;
}
.auth-card .gsi-material-button-contents { flex: 0 1 auto; overflow: visible; }
.auth-card .auth-provider-icon {
    display: block;
    flex: 0 0 24px;
    width: 24px;
    height: 24px;
    object-fit: contain;
}
.auth-card .auth-line { background: #06c755; color: #fff; border: 1px solid #06c755; }
.auth-card .auth-google { background: #fff; color: #1f1f1f; border: 1px solid #747775; }
.auth-card .auth-submit { background: #667eea; color: #fff; border: 0; cursor: pointer; font-weight: 700; }
.auth-card .auth-control:focus-visible { outline: 3px solid #2563eb; outline-offset: 3px; }
.auth-card .auth-social:hover { opacity: .85; }
@media screen and (max-width: 750px) {
    .auth-card { padding: 26px 20px; border-radius: 16px; }
}

.auth-migration-message { font-size: 16px; line-height: 1.8; margin-bottom: 24px; overflow-wrap: anywhere; }
.auth-migration-error { color: #b91c1c; background: #fef2f2; border-radius: 10px; padding: 14px 16px; margin-bottom: 18px; font-size: 14px; }
.auth-title.auth-migration-title {
    line-height: 1.5;
}

@media (max-width: 480px) {
    .auth-title.auth-migration-title {
        font-size: 18px;
    }
}