:root {
    --bg: #ffffff;
    --text: #111827;
    --muted: #6b7280;
    --border: #e5e7eb;
    --card: #f9fafb;
    --link: #2563eb;
    --warnbg: #fff7ed;
    --warnbd: #fed7aa;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Noto Sans JP", "Hiragino Kaku Gothic ProN","Yu Gothic","Meiryo", Arial, sans-serif;
    color: var(--text);
    background: var(--bg);
    line-height: 1.75;
}

header {
    height: 90px;
    padding: 18px 16px;
    border-bottom: 1px solid var(--border);
    background: var(--bg);
    position: sticky;
    top: 0;
    z-index: 10;
    /*background-image: url(../img/main_background.jpg);*/
}
    header .header {
        display: flex;
    }
    header .logo {
        margin-right: 12px; /* ロゴと文字の間隔 */
    }
        header .logo img {
            height: 48px; /* ロゴ高さ（必要に応じて調整） */
            width: auto;
            display: block;
        }
    header .text {
        display: flex;
        flex-direction: column; /* 縦2段 */
        line-height: 1.2;
    }
    header .title {
        margin: 0;
        font-size: 18px;
        font-weight: 700;
    }

    header .sub {
        display: block;
        margin-top: 6px;
        font-size: 13px;
        color: var(--muted);
    }

    header a {
        color: inherit; /* 親要素の色を継承する */
        text-decoration: none; /* 下線も消したい場合はこれを追加 */
    }

main {
    max-width: 920px;
    margin: 0 auto;
    padding: 16px;
}

.card {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: 14px;
    padding: 14px;
    margin: 12px 0 18px;
}

a {
    color: var(--link);
    text-decoration: none;
}

    a:hover {
        text-decoration: underline;
    }


footer {
    margin-top: 24px;
    padding: 18px 16px 28px;
    border-top: 1px solid var(--border);
    font-size: 12px;
    color: var(--muted);
}

    footer .company {
        margin-bottom: 8px;
        font-weight: 600;
        color: #111827;
    }

.muted {
    color: var(--muted);
    font-size: 13px;
}

.small {
    font-size: 12px;
    color: var(--muted);
}

.btn {
    display: inline-block;
    padding: 10px 12px;
    border-radius: 12px;
    border: 1px solid var(--border);
    background: #fff;
    color: var(--text);
    font-weight: 600;
    cursor: pointer;
}

    .btn.primary {
        background: #111827;
        border-color: #111827;
        color: #fff;
    }

.error {
    color: #b91c1c;
}

.ok {
    color: #065f46;
}